Science.gov

Sample records for brake fluid service

  1. Brake Fluid Compatibility with Hardware

    DTIC Science & Technology

    2014-05-19

    had two servo valves for each wheel. One of the wheel servo valves controlled pressurized fluid to the brake calipers , while the second servo valve...was responsible for anti-lock or brake release action by relieving caliper circuit pressure back to the reservoir. Brake circuit action was initiated...

  2. Brake Fluid Compatibility Studies with Advanced Brake Systems

    DTIC Science & Technology

    2016-01-16

    brake fluid in a hydraulic power brake system revealed deposits only with the silicone brake fluid after 20,000- cycles of testing. These results are...revealed deposits formed only with the silicone brake fluid after 20,000- cycles of testing. The objective was accomplished by conducting static soak...testing to halt when testing MIL-PRF-46176. Deposits were not present in SAE J1703 testing for the same number of test cycles . The objective of this

  3. Brakes Specialist. Teacher Edition. Automotive Service Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for a course on becoming an automotive brakes specialist, based on the National Institute of Automotive Service Excellence task lists. The course consists of three instructional units: service brake hydraulic system and wheel bearings, service drum brakes, and service disc brakes. Depending on the…

  4. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2011-10-01 2011-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  5. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2010-10-01 2010-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  6. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2012-10-01 2012-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  7. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2014-10-01 2014-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  8. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall... 49 Transportation 6 2013-10-01 2013-10-01 false Service brake system. 570.59 Section 570.59... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any...

  9. Effect of surface texture and working gap on the braking performance of the magnetorheological fluid brake

    NASA Astrophysics Data System (ADS)

    Wang, Na; Li, Dong Heng; Li Song, Wan; Chao Xiu, Shi; Zhi Meng, Xiang

    2016-10-01

    In this paper, the effect of the surface textures of braking disc on the braking performance is experimentally investigated under the conditions of different working gaps and applied currents. For this purpose, a new configuration of magnetorheological fluid brake (MRB) with adjustable working gap is developed to improve the manufacturing accuracy and cost, and to reduce the problem of replacing the braking disc. In addition, the braking discs with three types of surface texture are designed and machined. Based on the test bed developed for the proposed MRB, a series of experiments are carried out on the manufactured prototype and the results are presented to obtain the relationship among the surface texture of the braking disc, applied current, working gap and the braking performance. The results show that the braking torque is significantly influenced by the working gap and surface texture of the braking disc, and the maximum braking torque is obtained on the conditions of 0.25 mm working gap and the braking disc with square surface texture.

  10. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  11. Brake Fundamentals. Automotive Articulation Project.

    ERIC Educational Resources Information Center

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  12. An Instructor's Guide for a Program in Brake Services.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The instructor's guide is designed to present an understanding of the automotive hydraulic brake system and to help individuals develop new skills for employment in this specialized field of automotive service. Applicable for secondary or adult education, this guide describes: the brake system, types of brakes, diagnosis and correction of brake…

  13. Computational thermo-fluid analysis of a disk brake

    NASA Astrophysics Data System (ADS)

    Takizawa, Kenji; Tezduyar, Tayfun E.; Kuraishi, Takashi; Tabata, Shinichiro; Takagi, Hirokazu

    2016-06-01

    We present computational thermo-fluid analysis of a disk brake, including thermo-fluid analysis of the flow around the brake and heat conduction analysis of the disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning disk. The disk brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space-Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the brake, we do the heat conduction analysis of the disk, from the start of the breaking until the disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

  14. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing... 49 Transportation 6 2010-10-01 2010-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  15. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing... 49 Transportation 6 2012-10-01 2012-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  16. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing... 49 Transportation 6 2011-10-01 2011-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  17. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing... 49 Transportation 6 2013-10-01 2013-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  18. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing... 49 Transportation 6 2014-10-01 2014-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  19. Brakes Specialist. Teacher Edition. Automotive Service Series. Second Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide for automatic brakes service is one in a series of automotive service speciality publications that is based on the National Institute of Automotive Service Excellence task lists. The curriculum is composed of four units. Each unit of instruction may contain some or all of the following components: objective sheet, suggested…

  20. Design and testing of a rotational brake with shear thickening fluids

    NASA Astrophysics Data System (ADS)

    Tian, Tongfei; Nakano, Masami

    2017-03-01

    A rotational brake working with shear thickening fluid (STF) was designed and tested in this study. With the optimisation in design, most of the STF in the brake can receive the same shear rate when the brake rotates. The parts of this brake were fabricated with a 3D printer and then assembled manually. Three types of STFs with various carrier fluids and different particles were fabricated and tested with a rheometer. Then the brake with each STF was separately tested with the rheometer. The estimated and measured torques as a function of the angular velocity fit each other well. The stability of the rotational STF brake was investigated in repeated tests, which proved the function of the brake for a long time.

  1. Boiling point measurement of a small amount of brake fluid by thermocouple and its application.

    PubMed

    Mogami, Kazunari

    2002-09-01

    This study describes a new method for measuring the boiling point of a small amount of brake fluid using a thermocouple and a pear shaped flask. The boiling point of brake fluid was directly measured with an accuracy that was within approximately 3 C of that determined by the Japanese Industrial Standards method, even though the sample volume was only a few milliliters. The method was applied to measure the boiling points of brake fluid samples from automobiles. It was clear that the boiling points of brake fluid from some automobiles dropped to approximately 140 C from about 230 C, and that one of the samples from the wheel cylinder was approximately 45 C lower than brake fluid from the reserve tank. It is essential to take samples from the wheel cylinder, as this is most easily subjected to heating.

  2. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  3. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  4. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  5. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  6. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  7. Design of a squeeze film magnetorheological brake considering compression enhanced shear yield stress of magnetorheological fluid

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-02-01

    A magnetorheological brake, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnet, is proposed to replace the conventional heavy weight low response hydraulic disk brake. The frictional characteristics of the proposed brake can be controlled by regulating the yield stress of the MR fluid as function of magnetic field and normal compressive force. The controllable yield stress retards the surfaces of rotating disks, thus MR fluid can be used as a brake lining material. The present research work attempts designing a squeeze film MR brake by accounting compression enhanced shear yield stress of magnetorheological fluid. Theoretical calculations indicate that the estimated braking torque of the six plate squeeze film MR brake, under compression, is in the order of 600Nm. To validate the theoretical design and its findings, a prototype of single-plate squeeze film MR disk brake has been developed. Experimental test setup helps to illustrate braking torque under different control currents (0.0 to 1.25 A).

  8. 49 CFR 236.507 - Brake application; full service.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION... Train Stop, Train Control and Cab Signal Systems Standards § 236.507 Brake application; full service. The automatic train stop or train control apparatus shall, when operated, cause a full...

  9. 49 CFR 236.507 - Brake application; full service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION... Train Stop, Train Control and Cab Signal Systems Standards § 236.507 Brake application; full service. The automatic train stop or train control apparatus shall, when operated, cause a full...

  10. 49 CFR 236.507 - Brake application; full service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION... Train Stop, Train Control and Cab Signal Systems Standards § 236.507 Brake application; full service. The automatic train stop or train control apparatus shall, when operated, cause a full...

  11. 49 CFR 236.507 - Brake application; full service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION... Train Stop, Train Control and Cab Signal Systems Standards § 236.507 Brake application; full service. The automatic train stop or train control apparatus shall, when operated, cause a full...

  12. 49 CFR 236.507 - Brake application; full service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION... Train Stop, Train Control and Cab Signal Systems Standards § 236.507 Brake application; full service. The automatic train stop or train control apparatus shall, when operated, cause a full...

  13. Vibration control of an artificial muscle manipulator with a magnetorheological fluid brake

    NASA Astrophysics Data System (ADS)

    Tomori, H.; Midorikawa, Y.; Nakamura, T.

    2013-02-01

    Recently, proposed applications of robots require them to contact human safely. Therefore, we focus on pneumatic rubber artificial muscle. This actuator is flexible, light, and has high-power density. However, because the artificial muscle is flexible, it vibrates when there is a high load. Therefore, we paid attention to the magnetorheological (MR) fluid. We propose a control method of the MR brake considering energy of the manipulator system. By this control method, MR brake dissipates energy leading to vibration of the manipulator. In this paper, we calculated the energy and controlled the MR brake. And, we deliberated the proposal method by simulation using the dynamic model of the manipulator, and experiment.

  14. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... wheel cylinder cup into a test jar, immersed in water-wet brake fluid, capped and placed in an oven at..., the strips, SBR wheel cylinder cup and fluid are examined and tested. The performance results are... cylinder cups tested in each jar. One jar is heated to 70 degrees Celsius (158 degrees Fahrenheit) and...

  15. Well servicing fluid

    SciTech Connect

    Liao, A.

    1991-07-02

    This patent describes a well servicing fluid. It comprises an aqueous medium from about 0.2 to about 5 pounds per barrel of a partially hydrolyzed homopolymer of acrylamide having an average molecular weight greater than 1 million, and a calcium-controlling additive. It comprises from about 0.1 to about 2.5 pounds per barrel of the fluid of an alkali metal bicarbonate, from about 0.1 to about 2.5 pounds per barrel of the fluid of a water-soluble, carboxylic acid, and from about 0.1 to about 1.5 pounds per barrel of the fluid of a terpolymer containing from about 40 to about 70% by weight acrylamide, from about 20 to about 40% by weight of an acrylic acid and from about 5 to about 20% by weight of 2-acrylamido-2-methylpropanesulfonic acid, the terpolymer having an average molecular weight of from about 5 to about 10 million.

  16. 78 FR 21189 - Agency Requests for Approval of a New Information Collection: Motor Vehicle Brake Fluids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... as packagers of hydraulic system mineral oils. The information to be collected will be used to and/or... performance and design requirements for motor vehicle brake fluids and hydraulic system mineral oils. Section... packagers of hydraulic system mineral oils. The information on the label of a container of motor...

  17. Braking system

    DOEpatents

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  18. Optimal design of a new 3D haptic gripper for telemanipulation, featuring magnetorheological fluid brakes

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.; Lee, Y. S.; Han, M. S.

    2013-01-01

    In this research work, a new configuration of a 3D haptic gripper for telemanipulation is proposed and optimally designed. The proposed haptic gripper, featuring three magnetorheological fluid brakes (MRBs), reflects the rolling torque, the grasping force and the approach force from the slave manipulator to the master operator. After describing the operational principle of the haptic gripper, an optimal design of the MRBs for the gripper is performed. The purpose of the optimization problem is to find the most compact MRB that can provide a required braking torque/force to the master operator while the off-state torque/force is kept as small as possible. In the optimal design, different types of MRBs and different MR fluids (MRFs) are considered. In order to obtain the optimal solution of the MRBs, an optimization approach based on finite element analysis (FEA) integrated with an optimization tool is used. The optimal solutions of the MRBs are then obtained and the optimized MRBs for the haptic gripper are identified. In addition, discussions on the optimal solutions and performance of the optimized MRBs are given.

  19. Passive-type rehabilitation systems for upper limbs with MR fluid brake and its training software.

    PubMed

    Haraguchi, Makoto; Furusho, Junji

    2013-01-01

    It is important to construct rehabilitation system for elderly people, people who have suffered strokes, and so on. In recent years, the need for rehabilitation support systems is increasing that using force display devices. When using force display systems, it is most important to ensure safety mechanically in order to prevent operators from hurting. Conventional force display systems are active-type devices with actuators but these devices may become dangerous when going out of control. On the other hand, passive-type force display devices with only passive elements are thought to be an effective method for assuring inherent safety. In this paper, we evaluate force display ability about a 2-D passive-type force display device with fast-response MR (Magneto-Rheological) fluid brakes to apply this device to rehabilitation training.

  20. Preliminary survey report: evaluation of brake-drum service controls at Pennsylvania Bureau of Vehicle Management, Vehicle Maintenance Division, Harrisburg, Pennsylvania

    SciTech Connect

    Van Wagenen, H.D.

    1987-03-01

    Exposure to asbestos during the servicing of brakes on state-owned vehicles at the Bureau of Vehicle Management Maintenance Division, Harrisburg, Pennsylvania, was investigated as part of a study of control technologies. Brakes had been serviced at this garage facility for the previous year using a BCE-1000 Clayton brake-cleaning unit, sized for cars, vans, and pickups. The brake-cleaning unit consisted of a transparent enclosure hood and a HEPA vacuum filter dust collector, designed to contain and collect all brake-lining dust during vehicular brake maintenance and replacement. The authors conclude that the Clayton BCE-1000 dust-control unit appeared to be effective in containing and collecting brake dust during all vehicular brake maintenance and replacement jobs in this situation.

  1. Preliminary survey report: evaluation of brake-drum service controls at Louisville Gas and Electric Company, Louisville, Kentucky

    SciTech Connect

    Godbey, F.W.

    1985-12-01

    A survey of technology for controlling exposure to asbestos during brake-drum service operators was conducted. The major component of the engineering-control system was a Nilfisk Asbestos/Clene system that removed asbestos fibers generated while servicing the brakes. Each system consisted of a filtered dust collector and a brake-encapsulation cylinder. The workers were encouraged to use good work practices, such as completely vacuuming all exposed parts prior to handling, gently removing and handling all contaminated parts, and consistently using all required personal-protective equipment. The workers used approved masks. All employees were given annual chest x-rays and pulmonary function tests. The facility's vehicular brake-servicing facility appears to be well designed and maintained.

  2. Characterization of vehicular brake service personnel exposure to airborne asbestos and particulate.

    PubMed

    Weir, F W; Tolar, G; Meraz, L B

    2001-12-01

    Evaluation of fibers and total particulate generated during the servicing of drum brakes on motor vehicles as well as during the resurfacing (arcing) of brake shoes was conducted. Conditions for the studies were based on review of contemporary (approximately 1950-1980) working practices in the industry. This work was conducted in two parts. Phase 1 estimated the release of asbestos fibers and total particulate during brake inspection and replacement of light-duty vehicle rear drum brakes at an auto/truck repair facility. Two distinct work practices were evaluated: One rear wheel from each vehicle was serviced using compressed air to remove dust while the second rear wheel was serviced without compressed air. Area and personal monitoring of fiber levels demonstrated counts (without compressed air) that ranged from 0.05 to 0.2 f/cc. Fiber counts when using compressed air averaged from 0.05 to 0.9 f/cc. Results from real-time aerosol monitoring indicated elevated dust levels for about 15 minutes after blow out. With shop doors open, dust levels increased to 5.0 mg/m3 at blow out and returned to 0.08 mg/m3 within two minutes. When the shop doors were closed, the dust levels reached 13.5 mg/m3 at blow out and decreased to 1.68 mg/m3 within one minute and to background within 14 minutes. The Phase 2 series evaluated the release of fibers and other particulate from are grinding. For operations conducted under conditions simulating a workplace, a mean of 0.19 f/cc +/- 0.16 was determined. Dust levels averaged 0.25 mg/m3 +/- 0.05. Brake service monitoring in these tests demonstrates that asbestos fiber concentrations, considered on a time weighted average basis, should not exceed currently acceptable workplace standards whether or not the worker uses compressed air, nor during the arc grinding process when arcing is conducted in accord with the design of the equipment.

  3. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  4. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  5. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  6. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  7. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500... hole end of the test strip), the metal test strips shall not show pitting or etching to an...

  8. Preliminary survey report: evaluation of brake drum service controls at Indianapolis Power and Light Company, Indianapolis, Indiana

    SciTech Connect

    Godbey, F.W.

    1988-08-01

    An evaluation was made of various control technologies designed to reduce asbestos exposures during brake drum servicing at Indianapolis Power and Light Company, Indianapolis, Indiana. The garage at this facility serviced about 425 vehicles each year with about 200 brake repair jobs being done annually. During servicing, a regular wet and dry vacuum cleaner was used, along with a steam jenny containing liquid soap, and a liquid spray can. Once the wheel was removed, the entire hub area was sprayed with steam foam at 90 pounds per square inch from the steam jenny containing liquid soap. The hub area was vacuumed prior to and following removal. The vacuum cleaner was not equipped with an HEPA filter. A liquid spray can was used to clean the plates. The brake shoe area was vacuumed. Once the brake area was free of all accumulated dust, the brakes were serviced. The author concludes that control measures did not appear to be sufficient to keep asbestos dust from emanating into the atmosphere. The facility was not selected for an in-depth evaluation.

  9. Fluid Flow-Related Transport Phenomena in Steel Slab Continuous Casting Strands under Electromagnetic Brake

    NASA Astrophysics Data System (ADS)

    Wang, Yufeng; Zhang, Lifeng

    2011-12-01

    In the current study, a three-dimensinal (3D) numerical model is built to investigate the effect of a local-type electromagnetic brake (EMBr) on the fluid flow, heat transfer, and inclusion motion in slab continuous casting strands. The results indicate that the magnetic force affects the jet characteristics, including jet angle, turbulent kinetic energy, and its dissipation rate. To reduce the top surface velocity and stabilize the top surface, the magnetic flux intensity should be larger than a critical value. With a 0.39 T magnetic flux intensity, the top surface velocity and its fluctuation can be well controlled, and less slag is entrained. The motion of argon bubbles is also studied. More bubbles, especially >2.0-mm bubbles, escape from the top surface between the mold submerged entry nozzle (SEN) and 1/4 width for the case with a 0.39 T EMBr. This may push the top slag away and create an open "eye" on the top slag. Small bubbles (≤1 mm) tend to escape from one side of wide face no matter with or without EMBr, which is induced by the swirl flow from the SEN outport. EMBr has a little effect on the overall removal fraction of inclusions; however, it affects the local distribution of inclusion in the slab. With EMBr, more inclusions accumulate the region just below the surface, thus a worse subsurface quality, whereas the inner quality of the slab is better than that without EMBr. For heat transfer in the mold, the heat flux on the narrow face and the area of possible break-out zones can be reduced by using EMBr. Prevention of bias flow and/or asymmetrical flow in mold by EMBr is also concluded.

  10. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  11. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  12. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... the braking surface. (iii) Braking is to be performed using only those braking systems, including... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  13. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  14. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  15. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... initial speed at 20 mph Emergency brake systems Application and braking distance in feet from initial...-system application and braking distance in feet” (column 4) is a definite measure of the...

  16. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... the braking surface. (iii) Braking is to be performed using only those braking systems, including... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  17. Preliminary survey report: evaluation of brake-drum-service controls at US Army Armor Center, Fort Knox, Kentucky

    SciTech Connect

    Godbey, F.W.

    1988-08-01

    A visit was made to the U.S. Army Armor Center, Fort Knox, Kentucky, as part of a study of asbestos hazards encountered during the maintenance and repair of vehicular brakes. Approximately 800 vehicles were maintained at the center each year with about 100 brake jobs being needed during that course of time. Exposure to asbestos may occur during cleaning, maintenance, and repair of brakes. Workers were encouraged to use good work practices including the complete water rinsing and wet-bristle brushing of all exposed parts prior to handling, gently removing and handling all parts, consistently using all required personal protective equipment, and following instructions for use of asbestos-control devices. Annual physical examinations were provided for workers performing vehicular brake-repair services. The author concludes that the facility did not appear to have asbestos controls sufficient to protect the workers from asbestos dust arising from service operations. The advisability of conducting an in depth evaluation of the controls at the facility will be made in the future, after all the preliminary surveys and finalization of the protocol for the project has been reached.

  18. Four-wheel dual braking for automobiles

    NASA Technical Reports Server (NTRS)

    Edwards, H. B.

    1981-01-01

    Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

  19. Design of MR brake featuring tapered inner magnetic core

    NASA Astrophysics Data System (ADS)

    Sohn, Jung Woo; Oh, Jong-Soek; Choi, Seung-Bok

    2015-04-01

    In this work, a new type of MR brake featuring tapered inner magnetic core is proposed and its braking performance is numerically evaluated. In order to achieve high braking torque with restricted size and weight of MR brake system, tapered inner magnetic core is designed and expands the area that the magnetic flux is passing by MR fluid-filled gap. The mathematical braking torque model of the proposed MR brake is derived based on the field-dependent Bingham rheological model of MR fluid. Finite element analysis is carried out to identify electromagnetic characteristics of the conventional and the proposed MR brake configuration. To demonstrate the superiority of the proposed MR brake, the braking torque of the proposed MR brake is numerically evaluated and compared with that of conventional MR brake model.

  20. Gravity brake

    DOEpatents

    Lujan, Richard E.

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  1. Better Brakes

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

  2. Brakes. Auto Mechanics Curriculum Guide. Module 6. Instructor's Guide.

    ERIC Educational Resources Information Center

    Allain, Robert

    This module is the sixth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Eight units cover: introduction to automotive brake systems; disc and drum brake system components and how they operate; properties of brake fluid and procedures for bleeding the brake system; diagnosing and determining needed repairs on…

  3. Modelling and validation of magnetorheological brake responses using parametric approach

    NASA Astrophysics Data System (ADS)

    Z, Zainordin A.; A, Abdullah M.; K, Hudha

    2013-12-01

    Magnetorheological brake (MR Brake) is one x-by-wire systems which performs better than conventional brake systems. MR brake consists of a rotating disc that is immersed with Magnetorheological Fluid (MR Fluid) in an enclosure of an electromagnetic coil. The applied magnetic field will increase the yield strength of the MR fluid where this fluid was used to decrease the speed of the rotating shaft. The purpose of this paper is to develop a mathematical model to represent MR brake with a test rig. The MR brake model is developed based on actual torque characteristic which is coupled with motion of a test rig. Next, the experimental are performed using MR brake test rig and obtained three output responses known as angular velocity response, torque response and load displacement response. Furthermore, the MR brake was subjected to various current. Finally, the simulation results of MR brake model are then verified with experimental results.

  4. Magnetostrictive Brake

    NASA Technical Reports Server (NTRS)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

    A magnetostrictive brake has been designed as a more energy-efficient alternative to a magnetic fail-safe brake in a robot. (In the specific application, failsafe signifies that the brake is normally engaged; that is, power must be supplied to allow free rotation.) The magnetic failsafe brake must be supplied with about 8 W of electric power to initiate and maintain disengagement. In contrast, the magnetostrictive brake, which would have about the same dimensions and the same torque rating as those of the magnetic fail-safe brake, would demand only about 2 W of power for disengagement. The brake (see figure) would include a stationary base plate and a hub mounted on the base plate. Two solenoid assemblies would be mounted in diametrically opposed recesses in the hub. The cores of the solenoids would be made of the magnetostrictive alloy Terfenol-D or equivalent. The rotating part of the brake would be a ring-and spring- disk subassembly. By means of leaf springs not shown in the figure, this subassembly would be coupled with the shaft that the brake is meant to restrain. With no power supplied to the solenoids, a permanent magnet would pull axially on a stepped disk and on a shelf in the hub, causing the ring to be squeezed axially between the stepped disk and the hub. The friction associated with this axial squeeze would effect the braking action. Supplying electric power to the solenoids would cause the magnetostrictive cylinders to push radially inward against a set of wedges that would be in axial contact with the stepped disk. The wedges would convert the radial magnetostrictive strain to a multiplied axial displacement of the stepped disk. This axial displacement would be just large enough to lift the stepped disk, against the permanent magnetic force, out of contact with the ring. The ring would then be free to turn because it would no longer be squeezed axially between the stepped disk and the hub.

  5. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  6. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  7. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  8. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... mobile equipment shall be equipped with a service brake system capable of stopping and holding...

  9. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... provided in this section. (b) Service brakes—(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September 2, 1983, must, at a minimum, have a service...—partial failure of service brakes—(1) Hydraulic brake systems. Motor vehicles manufactured on or...

  10. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... provided in this section. (b) Service brakes—(1) Hydraulic brake systems. Motor vehicles equipped with hydraulic brake systems and manufactured on or after September 2, 1983, must, at a minimum, have a service...—partial failure of service brakes—(1) Hydraulic brake systems. Motor vehicles manufactured on or...

  11. Preliminary survey report: evaluation of brake-drum-service controls at Ohio Department of Transportation, Maintenance Facility, Lebanon, Ohio

    SciTech Connect

    Sheehy, J.W.

    1986-07-01

    The Ohio Department of Transportation, Maintenance Facility, Lebanon, Ohio, was visited as part of a study of asbestos control during the maintenance and repair of vehicular brakes. The effectiveness of various control technologies designed to reduce asbestos exposure were evaluated.

  12. BRAKE DEVICE

    DOEpatents

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  13. Automotive Brake Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

  14. Optimal design of a novel configuration of MR brake with coils placed on the side housings

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc Hung; Nguyen, Ngoc Diep; Choi, Seung-Bok

    2014-03-01

    It is well known that in design of traditional magneto-rheological brake (MRB), coils are placed on the cylindrical housing of the brake. In this study, a new configuration of MR brake with coils placed on the side housings of the brake is proposed and analyzed. After briefly explaining the operating principle of the proposed configuration, the braking torque of the MR brake is analyze based on Bingham-plastic rheological model of MR fluid. The optimization of the proposed and conventional MR brakes is then performed considering maximum braking torque and mass of the brake. Based on the optimal results, a comparison between the proposed MR brakes and the conventional ones is undertaken. In addition, experimental test of the MR brakes is conducted and the results are presented in order to validate the performance characteristics of the proposed MR brake.

  15. Electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, Susan R.

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  16. Electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  17. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  18. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  19. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  20. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  1. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  2. 76 FR 9717 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ..., however, specify performance requirements for the emergency brakes, after the service braking system has... antilock braking systems (ABS) on the lead unit. Some of the combinations tested exceeded 75 feet in length... & Associates, Inc., Vehicle Systems Consultants (August 1996). ``Braking and Offtracking Tests on...

  3. 76 FR 56318 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-13

    .../pdf/E8-785.pdf . II. Abbreviations ABS antilock braking systems. ACC Automobile Carriers Conference... performance requirements for the emergency brakes, which deploy after the service braking system has failed... for Safe Operation; Saddle-Mount Braking Requirements AGENCY: Federal Motor Carrier...

  4. In-depth survey report: evaluation of brake drum service controls at United States Postal Service Vehicle Maintenance Facility, Louisville, Kentucky

    SciTech Connect

    Cooper, T.C.; Sheehy, J.W.; O'Brien, D.M.; McGlothlin, J.D.; Todd, W.F.

    1987-12-01

    A control technology assessment of various methods to control worker exposure to asbestos during brake repair was reported for the Vehicle Maintenance Facility at the U.S. Post Office Building in Louisville, Kentucky. Results indicated that effective control of asbestos dust was achieved with the system used; one of 22 samples had a detectable level. Recommendations for better work practices were presented.

  5. Optimal design and selection of magneto-rheological brake types based on braking torque and mass

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Lang, V. T.; Choi, S. B.

    2015-06-01

    In developing magnetorheological brakes (MRBs), it is well known that the braking torque and the mass of the MRBs are important factors that should be considered in the product’s design. This research focuses on the optimal design of different types of MRBs, from which we identify an optimal selection of MRB types, considering braking torque and mass. In the optimization, common types of MRBs such as disc-type, drum-type, hybrid-type, and T-shape types are considered. The optimization problem is to find an optimal MRB structure that can produce the required braking torque while minimizing its mass. After a brief description of the configuration of the MRBs, the MRBs’ braking torque is derived based on the Herschel-Bulkley rheological model of the magnetorheological fluid. Then, the optimal designs of the MRBs are analyzed. The optimization objective is to minimize the mass of the brake while the braking torque is constrained to be greater than a required value. In addition, the power consumption of the MRBs is also considered as a reference parameter in the optimization. A finite element analysis integrated with an optimization tool is used to obtain optimal solutions for the MRBs. Optimal solutions of MRBs with different required braking torque values are obtained based on the proposed optimization procedure. From the results, we discuss the optimal selection of MRB types, considering braking torque and mass.

  6. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  7. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  8. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  9. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  10. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system,...

  11. Space transportation system disconnect. [replenishing fluids during orbital servicing

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The use of medium duty 300 psi fluid disconnects for orbital servicing was demonstrated to be both practical and technically feasible. A prototype disconnect was designed and tested, based on criteria formulated from a survey of expected usage requirements for orbital servicing concepts. Testing involved the comparison of three seal materials (EPR, Neoprene and Teflon), and two test media (helium and Freon 21), and was conducted over a temperature range of -150 F to +225 F. Results indicate low helium leakage (10 to the -4 power sccs) and extremely low engagement forces (56 lb sub f). Testing was also performed on a new seal design. Design concepts for a cryogenic disconnect and a high pressure disconnect were investigated. Results of an industry survey for usable orbital servicing disconnects and areas needing attention in future studies are discussed.

  12. Antiskid braking system

    NASA Technical Reports Server (NTRS)

    Pazdera, J. S.

    1974-01-01

    Published report describes analytical development and simulation of braking system. System prevents wheels from skidding when brakes are applied, significantly reducing stopping distance. Report also presents computer simulation study on system as applied to aircraft.

  13. Geometric optimal design of a magneto-rheological brake considering different shapes for the brake envelope

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Lang, V. T.; Nguyen, N. D.; Choi, S. B.

    2014-01-01

    When designing a magneto-rheological brake (MRB), it is well known that the shape of the brake envelope significantly affects the performance characteristics of the brake. In this study, different shapes for the MR brake envelope, such as rectangular, polygonal or spline shape, are considered and the most suitable shape identified. MRBs with different envelope shapes are introduced followed by the derivation of the braking torque based on Bingham-plastic behavior of the magneto-rheological fluid (MRF). Optimization of the design of the MRB with different envelope shapes is then done. The optimization problem is to find the optimal value for the significant geometric dimensions of the MRB that can produce a certain required braking torque while the brake mass is minimized. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions for the MRBs. From the results, the most suitable shape for the brake envelope is identified and discussed with the reduction of mass. In addition, the results of the analysis are compared with the experimental results to verify the proposed optimal design characteristics.

  14. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... 16 17 18 19 20 Service Brake Maximum Stopping Distance—Feet 0-36,000 34 38 43 48 53 59 64 70 76 83 89... 140,000-250,000 56 62 69 77 84 92 100 108 116 125 133 250,000-400,000 59 66 74 81 89 97 105 114...

  15. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-11-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel-Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0-2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

  16. Reel safety brake

    NASA Technical Reports Server (NTRS)

    Carle, C. E. (Inventor)

    1976-01-01

    A braking apparatus is described for a tape transport device having two stacked coaxial reels and feelers mounted in proximity to the reels for sensing the tape being wound on each reel. A device is mounted in proximity to adjacent central hubs of the reels to a simultaneously, frictionally engage both hubs and brake both reels. A mechanical actuator is coupled to both feelers and to the brake device. The brake means comprises a pair of rubber shoulders that extend in opposite directions relative to a common axis, and turns about the axis in response to either of the feelers.

  17. An antilock molecular braking system.

    PubMed

    Sun, Wei-Ting; Huang, Shou-Ling; Yao, Hsuan-Hsiao; Chen, I-Chia; Lin, Ying-Chih; Yang, Jye-Shane

    2012-08-17

    A light-driven molecular brake displaying an antilock function is constructed by introducing a nonradiative photoinduced electron transfer (PET) decay channel to compete with the trans (brake-off) → cis (brake-on) photoisomerization. A fast release of the brake can be achieved by deactivating the PET process through addition of protons. The cycle of irradiation-protonation-irradiation-deprotonation conducts the brake function and mimics the antilock braking system (ABS) of vehicles.

  18. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake...

  19. A New Dynamometer Brake

    NASA Technical Reports Server (NTRS)

    Segre, Marco

    1921-01-01

    The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.

  20. Development of a multi-pole magnetorheological brake

    NASA Astrophysics Data System (ADS)

    Shiao, Yaojung; Nguyen, Quang-Anh

    2013-06-01

    This paper presents a new approach in the design and optimization of a novel multi-pole magnetorheological (MR) brake that employs magnetic flux more effectively on the surface of the rotor. MR brakes with conventional single ring-type electromagnetic poles have reached the limits of torque enhancement. One major reason is the limitation of the magnetic field strength within the active area of the MR fluid due to the geometric constraints of the coil. The multi-pole MR brake design features multiple electromagnetic poles surrounded by several coils. As a result, the active chaining areas for the MR fluid are greatly increased, and significant brake torque improvement is achieved. The coil structure, as a part of the stator, becomes flexible and customizable in terms of space usage for the winding and bobbin design. In addition, this brake offers extra options in its dimensions for torque enhancement because either the radial or the axial dimensions of the rotor can be increased. Magnetic circuit analysis was conducted to analyze the effects of the design parameters on the field torque. After that, simulations were done to find the optimal design under all major geometric constraints with a given power supply. The results show that the multi-pole MR brake provides a considerable braking torque increase while maintaining a compact and solid design. This is confirmation of its feasibility in actual braking applications.

  1. Braking system for use with an arbor of a microscope

    DOEpatents

    Norgren, Duane U.

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  2. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the terminal complex with passengers; (2) Prior to the first morning departure of each commuter or... operator first takes charge of the train, except for face-to-face relief. (b) A Class II brake test shall... locomotives that utilize an electric signal to communicate a service brake application and only a...

  3. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets...

  4. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets...

  5. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....315(a)(1); (3) When previously tested units (i.e., cars that received a Class I brake test within the... hours) are added to the train; (4) When cars or equipment are removed from the train; and (5) When an... locomotives that utilize an electric signal to communicate a service brake application and only a...

  6. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....315(a)(1); (3) When previously tested units (i.e., cars that received a Class I brake test within the... hours) are added to the train; (4) When cars or equipment are removed from the train; and (5) When an... locomotives that utilize an electric signal to communicate a service brake application and only a...

  7. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the...

  8. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the...

  9. WIND BRAKING OF MAGNETARS

    SciTech Connect

    Tong, H.; Xu, R. X.; Qiao, G. J.; Song, L. M.

    2013-05-10

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L{sub x}<- E-dot{sub rot} may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  10. Optimal design of a magneto-rheological brake absorber for torsional vibration control

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.

    2012-02-01

    This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given.

  11. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, Susan R.

    1994-01-01

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

  12. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, S.R.

    1994-10-25

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

  13. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its... Class I or IA brake test. Passenger equipment hauled or used in service in a commuter or passenger train... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which...

  14. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its... Class I or IA brake test. Passenger equipment hauled or used in service in a commuter or passenger train... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which...

  15. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its... Class I or IA brake test. Passenger equipment hauled or used in service in a commuter or passenger train... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which...

  16. Development of a multilayered wide-ranged torque magnetorheological brake

    NASA Astrophysics Data System (ADS)

    Rossa, Carlos; Jaegy, Adrien; Micaelli, Alain; Lozada, José

    2014-02-01

    This paper presents the design of a multilayered magnetorheological brake from modelling to prototyping and characterization. A magnetostatic model intended to provide a specific magnetic flux density over a fluid gap regardless of the dimensions of the fluid surface is proposed. The ferromagnetic path and the coil are dimensioned in consequence. The model needs only three inputs to completely define the brake, i.e. the number of fluid gaps, the inner radius of the smallest fluid gap and the fluid gap depth. The evaluation criteria are defined by the torque density, the controllability and the reactivity, described as a function of the dimensions and the number of fluid gaps. The model has been optimized to improve the torque density. The brake has four fluid gaps and has been built and characterized. The expected torque when the fluid reaches the desired induction is 3.4 N m and the measured torque is 3.6 N m. This represents a relative error of 5.5%. The brake has 60 mm diameter, 39 mm width with a hollow shaft of 12 mm diameter. When exploited up to complete saturation, the measured torque is 5.3 N m with 19 W power consumption. The brake has a torque density of 48.1 kN m-2 and a maximum-to-minimum torque ratio of 176, with 50 ms electromechanical time constant.

  17. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    NASA Astrophysics Data System (ADS)

    Wibowo, Zakaria, Lambang, Lullus; Triyono, Muhayat, Nurul

    2016-03-01

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  18. Improved Electromagnetic Brake

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may

  19. A preliminary assessment of asbestos awareness and control measures in brake and clutch repair services in Knoxville and Knox County, Tennessee

    SciTech Connect

    Phillips, C.C. ); Hamilton, C.B.

    1994-04-01

    The pending OSHA standard revision proposed in 1990 to lower the asbestos Permissible Exposure Limit (PEL) and to mandate effective asbestos control measures (ACM) in brake and clutch assembly work may have a profound effect on industries involved in such operations. Health protection of workers will be improved and costs of improved control methods and training will increase. Considering these facts, this preliminary study was designed to assess the level of worker and management awareness of asbestos hazards associated with brake and clutch repair and to determine what ACM had been implemented by businesses in Knoxville and Knox County, Tennessee. The study, in a metropolitan area of approximately 336,000 people, revealed eight different categories of businesses conducting brake and clutch repair work with an estimated 363 potentially exposed employees. Results of the study suggest that managers and employees of the 80 businesses studied were in need of asbestos hazard awareness training and more adequate asbestos control measures.

  20. Braking System for Wind Turbines

    NASA Technical Reports Server (NTRS)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  1. Design optimization of a magnetorheological brake in powered knee orthosis

    NASA Astrophysics Data System (ADS)

    Ma, Hao; Liao, Wei-Hsin

    2015-04-01

    Magneto-rheological (MR) fluids have been utilized in devices like orthoses and prostheses to generate controllable braking torque. In this paper, a flat shape rotary MR brake is designed for powered knee orthosis to provide adjustable resistance. Multiple disk structure with interior inner coil is adopted in the MR brake configuration. In order to increase the maximal magnetic flux, a novel internal structure design with smooth transition surface is proposed. Based on this design, a parameterized model of the MR brake is built for geometrical optimization. Multiple factors are considered in the optimization objective: braking torque, weight, and, particularly, average power consumption. The optimization is then performed with Finite Element Analysis (FEA), and the optimal design is obtained among the Pareto-optimal set considering the trade-offs in design objectives.

  2. Vehicle brake testing system

    SciTech Connect

    Stevens, Samuel S; Hodgson, Jeffrey W

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  3. Evaluation of materials and design modifications for aircraft brakes

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  4. A Comparative Study on Automotive Brake Testing Standards

    NASA Astrophysics Data System (ADS)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  5. The antilock braking system anomaly: a drinking driver problem?

    PubMed

    Harless, David W; Hoffer, George E

    2002-05-01

    Antilock braking systems (ABS) have held promise for reducing the incidence of accidents because they reduce stopping times on slippery surfaces and allow drivers to maintain steering control during emergency braking. Farmer et al. (Accident Anal. Prevent. 29 (1997) 745) provide evidence that antilock brakes are beneficial to nonoccupants: a set of 1992 model General Motors vehicles equipped with antilock brakes were involved in significantly fewer fatal crashes in which occupants of other vehicles, pedestrians, or bicyclists were killed. But, perversely, the risk of death for occupants of vehicles equipped with antilock brakes increased significantly after adoption. Farmer (Accident Anal. Prevent. 33 (2001) 361) updates the analysis for 1996- 1998 and finds a significant attenuation in the ABS anomaly. Researchers have put forward two hypotheses to explain this antilock brake anomaly: risk compensation and improper operation of antilock brake-equipped vehicles. We provide strong evidence for the improper operation hypothesis by showing that the antilock brake anomaly is confined largely to drinking drivers. Further, we show that the attenuation phenomenon occurs consistently after the first three to four years of vehicle service.

  6. Safety brake for tape reels

    NASA Technical Reports Server (NTRS)

    Carle, C. E.

    1977-01-01

    All-mechanical device senses end of tape and stops reel, even in event of electronic system failure. Assembly includes stop to prevent brake from overriding tape. Recentering mechanism returns brake to neutral position after torque is removed from reels.

  7. Brake-By-Wire Program

    DTIC Science & Technology

    2006-05-31

    SUPPLEMENTARY NOTES Report contains color. 14. ABSTRACT Two design iterations for electric calipers and two systems (full brake by wire and hybrid brakes ...were developed for use on a ground vehicle. The program demonstrated a fully integrated electric caliper and full brake -by-wire system on a sports...release. Project Context The development of an electric brake caliper and associated systems for automotive application represented a significant

  8. Optimal design of a novel hybrid MR brake for motorcycles considering axial and radial magnetic flux

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.

    2012-05-01

    This work presents an optimal solution of a new type of motorcycle brake featuring different smart magnetorheological (MR) fluids. In this study, typical types of commercial MR fluid are considered there for the design of a motorcycle MR brake; MRF-122-2ED (low yield stress), MRF-132-DG (medium yield stress) and MRF-140-CG (high yield stress). As a first step, a new configuration featuring a T-shaped drum MR brake is introduced and a hybrid concept of magnetic circuit (using both axial and radial magnetic flux) to generate braking force is analyzed based on the finite element method. An optimal design of the MR brake considering the required braking torque, the temperature due to friction of the MR fluid, the mass of the brake system and all significant geometric dimensions is then performed. For the optimization, the finite element analysis (FEA) is used to achieve principal geometric dimensions of the MR brake. In addition, the size, mass and power consumption of three different MR motorcycle brakes are quantitatively analyzed and compared.

  9. Optimal design of disc-type magneto-rheological brake for mid-sized motorcycle: experimental evaluation

    NASA Astrophysics Data System (ADS)

    Sohn, Jung Woo; Jeon, Juncheol; Nguyen, Quoc Hung; Choi, Seung-Bok

    2015-08-01

    In this paper, a disc-type magneto-rheological (MR) brake is designed for a mid-sized motorcycle and its performance is experimentally evaluated. The proposed MR brake consists of an outer housing, a rotating disc immersed in MR fluid, and a copper wire coiled around a bobbin to generate a magnetic field. The structural configuration of the MR brake is first presented with consideration of the installation space for the conventional hydraulic brake of a mid-sized motorcycle. The design parameters of the proposed MR brake are optimized to satisfy design requirements such as the braking torque, total mass of the MR brake, and cruising temperature caused by the magnetic-field friction of the MR fluid. In the optimization procedure, the braking torque is calculated based on the Herschel-Bulkley rheological model, which predicts MR fluid behavior well at high shear rate. An optimization tool based on finite element analysis is used to obtain the optimized dimensions of the MR brake. After manufacturing the MR brake, mechanical performances regarding the response time, braking torque and cruising temperature are experimentally evaluated.

  10. Evaluation of the Flush/Fill and High-Pressure Air Purge Procedures for Converting Army Vehicles to Silicone Brake Fluid.

    DTIC Science & Technology

    1982-02-01

    dispersed spray/ fog . 4 100 Acetylene 50 The initial spray was ignited by the torch Torch and burned until the fluid/air ratio be- came too low to support... burning . 5 150 None 40 A spray ot large droplets followed by a very finely dispersed spray/ fog . 6 150 Acetylene 40 The initial spray was ignited by...Results ! 50 None 60 Initially a spray of large droplets followed by a very fine mist/ fog . 2 50 Acetylene 60 The initial mist was ignited by the torch

  11. Heat distribution in disc brake

    NASA Astrophysics Data System (ADS)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

    This article is deals by the thermal analysis of the disc brake with floating caliper. The issue is solved by numerically. The half 2D model is used for solution in program ADINA 8.8. Two brake discs without the ventilation are solved. One disc is made from cast iron and the second is made from stainless steel. Both materials are an isotropic. By acting the pressure force on the brake pads will be pressing the pads to the brake disc. Speed will be reduced (slowing down). On the contact surface generates the heat, which the disc and pads heats. In the next part of article is comparison the maximum temperature at the time of braking. The temperatures of both materials for brake disc (gray cast iron, stainless steel) are compares. The heat flux during braking for the both materials is shown.

  12. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., 1974) at 40 mph, omitting water delivery as specified in paragraphs 7.1 and 7.2 of that method... brake system—fade and recovery. These requirements do not apply to a motor-driven cycle whose speed... cycle whose speed attainable in 1 mile is 30 mph or less. S5.5.1Service brake system. The service...

  13. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  14. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  15. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  16. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  17. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  18. Experiments with airplane brakes

    NASA Technical Reports Server (NTRS)

    Michael, Franz

    1931-01-01

    This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading. From the load distribution we merely defined the position of the normal force resultant, while for the rest, the effect of the distribution was disregarded in the comparison of the different shoe dispositions.

  19. Deployable Engine Air Brake

    NASA Technical Reports Server (NTRS)

    2014-01-01

    On approach, next-generation aircraft are likely to have airframe noise levels that are comparable to or in excess of engine noise. ATA Engineering, Inc. (ATA) is developing a novel quiet engine air brake (EAB), a device that generates "equivalent drag" within the engine through stream thrust reduction by creating a swirling outflow in the turbofan exhaust nozzle. Two Phase II projects were conducted to mature this technology: (1) a concept development program (CDP) and (2) a system development program (SDP).

  20. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  1. Combined hydraulic and regenerative braking system

    SciTech Connect

    Venkataperumal, Rama R.; Mericle, Gerald E.

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  2. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  3. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  4. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  5. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  6. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.53 Brake gauges. All... engineer to aid in the control or braking of the train or locomotive shall be located so that they may...

  7. Emergency Brake for Tracked Vehicles

    NASA Technical Reports Server (NTRS)

    Green, G. L.; Hooper, S. L.

    1986-01-01

    Caliper brake automatically stops tracked vehicle as vehicle nears end of travel. Bar on vehicle, traveling to right, dislodges block between brake pads. Pads then press against bar, slowing vehicle by friction. Emergencybraking system suitable for elevators, amusement rides and machine tools.

  8. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... pedal force upon the service brake. (2) Without the application of pedal force, when the level of brake....1Baseline check—minimum and maximum pedal forces. The pedal and lever forces used in establishing the fade... pedal force that does not exceed 400 Newtons (90 pounds), and a hand lever force that does not...

  9. Automatic transmission brake assembly including an overrunning roller brake and a friction brake

    SciTech Connect

    Premiski, V.; Hohnel, R.; Premiski, C.

    1988-10-11

    This patent describes an overrunning roller brake assembly for a planetary gear unit in an automatic transmission for automobiles, the gear unit having a ring gear, a carrier and a sun gear, the carrier having planet pinions thereon engaging the sun and ring gears; a brake for anchoring a reaction member of the gear unit, at least one other member of the gear unit being adapted to receive driving torque; the brake comprising an annular inner brake race surrounding a fixed part of the transmission, an annular outer brake race connected to the reaction member and surrounding the inner race, the outer race comprising an extrusion with an outer brake drum surface adapted to be engaged by a reaction friction brake band; overrunning brake rollers between the races, a pair of support rings between the races on either side of the rollers; the support rings having a C-shaped cross section whereby the inner and outer surfaces thereof provide a bearing support for the races; retainer rings enclosed within the support rings, the retainer rings having a radial thickness approximately equal to the radial inside dimension of the C-shaped cross section of the support rings whereby radial loads are transmitted between the races through the retainer rings and support rings.

  10. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  11. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  12. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  13. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... indicators. 393.53 Section 393.53 Transportation Other Regulations Relating to Transportation (Continued... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial... vehicle at the time it was manufactured. (c) Brake adjustment indicator (air brake systems). On...

  14. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  15. 49 CFR 393.53 - Automatic brake adjusters and brake adjustment indicators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... brake adjustment indicators. (a) Automatic brake adjusters (hydraulic brake systems). Each commercial motor vehicle manufactured on or after October 20, 1993, and equipped with a hydraulic brake system, shall meet the automatic brake adjustment system requirements of Federal Motor Vehicle Safety...

  16. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  17. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  18. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  19. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... reading by the number of brakes and determine the brake amperage value. (b) Electric brake...

  20. Pulsation dampening device for super critical fluid expansion engine, hydraulic engine or pump in cryogenic service

    SciTech Connect

    Ness, L.A.

    1989-11-07

    This patent describes a surge bottle or pressure pulsation dampening device for cryogenic services. It comprises: a liquid sump section, wherein the liquid sump section is comprised of an enclosed area containing a volume of an incompressible fluid; a warm gas volume section, wherein the warm gas volume section is comprised of an enclosed area containing a volume of a compressible warm gas; and a laminar flow section which connects and allows for communication between the liquid sump section and the warm gas volume section. The laminar flow section is comprised of a number of small bore, thin walled tubes which contain the incompressible fluid in the end connected to the liquid sump section and the compressible warm gas in the end connected to the warm gas volume section wherein the bore of the tubes are such that any movement of the either the compressible warm gas or the incompressible fluid would be laminar flow. During operation, the incompressible fluid and the warm compressible gas within the small bore, thin walled tubes move or oscillate a short distance in each of the tubes with minimal intermixing of the incompressible fluid and the warm compressible gas thereby minimizing heat leak from the warm gas volume section to the liquid sump section into the liquid in the sump.

  1. Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

    NASA Astrophysics Data System (ADS)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Liu, Yahui; Song, Jian; Ran, Xu

    2016-02-01

    Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

  2. Electrorheological fluids

    SciTech Connect

    Adolf, D.; Anderson, R.; Garino, T.; Halsey, T.C.; Hance, B.; Martin, J.E.; Odinek, J.

    1996-10-01

    An Electrorheological fluid is normally a low-viscosity colloidal suspension, but when an electric field is applied, the fluid undergoes a reversible transition to a solid, being able to support considerable stress without yield. Commercial possibilities for such fluids are enormous, including clutches, brakes, valves,shock absorbers, and stepper motors. However, performance of current fluids is inadequate for many proposed applications. Our goal was to engineer improved fluids by investigating the key technical issues underlying the solid-phase yield stress and the liquid to solid switching time. Our studies focused on field-induced interactions between colloidal particles that lead to solidification, the relation between fluid structure and performance (viscosity, yield stress), and the time evolution of structure in the fluid as the field is switched on or off.

  3. Prosthetic leg powered by MR brake and SMA wires

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  4. Mechanical Mixer for Rudder/Braking Wedge

    NASA Technical Reports Server (NTRS)

    Grimm, D.

    1985-01-01

    Right and left rudder panels moved separately. Mechanical mixer enables panels of two-panel rudder to rotate in same direction for steering or in opposite directions for dynamic braking. Steering and braking inputs separate so any combination of steering and braking motions executed simultaneously. Developed for aerodynamic braking of Space Shuttle orbiter, steering/braking drive train and rudder arrangement used for similar purposes on aircraft, thereby reducing sizes of thrust reversers.

  5. Wheel brakes and their application to aircraft

    NASA Technical Reports Server (NTRS)

    Dowty, G H

    1928-01-01

    The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls.

  6. Brake Stops Both Rotation And Translation

    NASA Technical Reports Server (NTRS)

    Allred, Johnny W.; Fleck, Vincent J., Jr.

    1995-01-01

    Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

  7. Regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1982-01-12

    Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

  8. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  9. Fuel cell assembly unit for promoting fluid service and electrical conductivity

    DOEpatents

    Jones, Daniel O.

    1999-01-01

    Fluid service and/or electrical conductivity for a fuel cell assembly is promoted. Open-faced flow channel(s) are formed in a flow field plate face, and extend in the flow field plate face between entry and exit fluid manifolds. A resilient gas diffusion layer is located between the flow field plate face and a membrane electrode assembly, fluidly serviced with the open-faced flow channel(s). The resilient gas diffusion layer is restrained against entering the open-faced flow channel(s) under a compressive force applied to the fuel cell assembly. In particular, a first side of a support member abuts the flow field plate face, and a second side of the support member abuts the resilient gas diffusion layer. The support member is formed with a plurality of openings extending between the first and second sides of the support member. In addition, a clamping pressure is maintained for an interface between the resilient gas diffusion layer and a portion of the membrane electrode assembly. Preferably, the support member is spikeless and/or substantially flat. Further, the support member is formed with an electrical path for conducting current between the resilient gas diffusion layer and position(s) on the flow field plate face.

  10. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... first morning departure of each commuter or short-distance intercity passenger train, unless all of the... repeated at the first passenger terminal if the train remains on a source of compressed air and: (1) The... that utilize an electric signal to communicate a service brake application and only a pneumatic...

  11. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic.... (3) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets this requirement. [64 FR 25660, May 12, 1999, as amended at 65 FR...

  12. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic.... (3) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets this requirement....

  13. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment of each cab car shall be..., KB-HS1, or Fastbrake brake systems. (2) Every 1,476 days for that portion of the cab car brake system... that portion of the cab car brake system using brake valves that are identical to the locomotive...

  14. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment of each cab car shall be..., KB-HS1, or Fastbrake brake systems. (2) Every 1,476 days for that portion of the cab car brake system... that portion of the cab car brake system using brake valves that are identical to the locomotive...

  15. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is... the case of tread or disc brakes by determining that the brake shoe or pad provides pressure to the... of the clearance between the brake shoe and the wheel or between the brake pad and the brake disc....

  16. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is... the case of tread or disc brakes by determining that the brake shoe or pad provides pressure to the... of the clearance between the brake shoe and the wheel or between the brake pad and the brake disc....

  17. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is... the case of tread or disc brakes by determining that the brake shoe or pad provides pressure to the... of the clearance between the brake shoe and the wheel or between the brake pad and the brake disc....

  18. A Demonstration of Car Braking Instabilities.

    ERIC Educational Resources Information Center

    Irwin, Jack; Swinson, Derek

    1990-01-01

    Detailed are the construction of a demonstration car, apparatus and procedures used in the demonstration, and the analysis of the effects of car braking. The cases of rear-wheel and front-wheel braking are considered. (CW)

  19. Compact, Lightweight Servo-Controllable Brakes

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  20. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  1. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  2. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  3. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... wheel braking system must not exceed the pressure specified by the brake manufacturer. (d) If antiskid devices are installed, the devices and associated systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of...

  4. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  5. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  6. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect

    Wilson, DF

    2002-10-22

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

  7. Interactive design optimization of magnetorheological-brake actuators using the Taguchi method

    NASA Astrophysics Data System (ADS)

    Erol, Ozan; Gurocak, Hakan

    2011-10-01

    This research explored an optimization method that would automate the process of designing a magnetorheological (MR)-brake but still keep the designer in the loop. MR-brakes apply resistive torque by increasing the viscosity of an MR fluid inside the brake. This electronically controllable brake can provide a very large torque-to-volume ratio, which is very desirable for an actuator. However, the design process is quite complex and time consuming due to many parameters. In this paper, we adapted the popular Taguchi method, widely used in manufacturing, to the problem of designing a complex MR-brake. Unlike other existing methods, this approach can automatically identify the dominant parameters of the design, which reduces the search space and the time it takes to find the best possible design. While automating the search for a solution, it also lets the designer see the dominant parameters and make choices to investigate only their interactions with the design output. The new method was applied for re-designing MR-brakes. It reduced the design time from a week or two down to a few minutes. Also, usability experiments indicated significantly better brake designs by novice users.

  8. Design and evaluation of a novel magnetorheological brake with coils placed on the side housings

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc Hung; Diep Nguyen, Ngoc; Bok Choi, Seung

    2015-04-01

    In the design of a traditional magnetorheological brake (MRB), coils are often placed on the cylindrical housing of the brake. This results in many disadvantages such as a ‘bottle-neck’ problem of magnetic flux. Moreover, in this design a nonmagnetic bobbin is required, and difficulties in manufacturing and maintenance exist. In order to resolve this problem, in this study a new configuration of MRB with coils placed on the side housings of the brake is proposed, optimally designed and experimentally evaluated. After describing an introduction of the proposed configuration, braking torque of the MRB is analyzed based on the Bingham-plastic rheological model of magnetorheological fluid (MRF). The optimization of the proposed and conventional MRBs is then performed considering maximum braking torque and mass of the brakes. In the optimization, both rectangular and polygonal shapes of the brake housing are considered. Based on the optimal results, a comparison of the performance characteristics of the proposed MRB and the conventional one is undertaken. In addition, an experimental test of the MRBs is conducted, and the results are presented in order to validate the performance characteristics of the proposed MRB.

  9. Bidirectional drive and brake mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A. (Inventor)

    1991-01-01

    A space transport vehicle is disclosed as including a body which is arranged to be movably mounted on an elongated guide member disposed in outer space and driven therealong. A drive wheel is mounted on a drive shaft and arranged to be positioned in rolling engagement with the elongated guide carrying the vehicle. A brake member is arranged on the drive shaft for movement into and out of engagement with an adjacent surface of the drive wheel. An actuator is mounted on the body to be manually moved back and forth between spaced positions in an arc of movement. A ratchet-and-pawl mechanism is arranged to operate upon movements of the actuator in one direction between first and second positions for coupling the actuator to the drive wheel to incrementally rotate the wheel in one rotational direction and to operate upon movements of the actuator in the opposite direction for uncoupling the actuator from the wheel. The brake member is threadedly coupled to the drive shaft in order that the brake member will be operated only when the actuator is moved on beyond its first and second positions for shifting the brake member along the drive shaft and into frictional engagement with the adjacent surface on the drive wheel.

  10. Brake blending strategy for a hybrid vehicle

    SciTech Connect

    Boberg, Evan S.

    2000-12-05

    A hybrid electric powertrain system is provided including a transmission for driving a pair of wheels of a vehicle and a heat engine and an electric motor/generator coupled to the transmission. A friction brake system is provided for applying a braking torque to said vehicle. A controller unit generates control signals to the electric motor/generator and the friction brake system for controllably braking the vehicle in response to a drivers brake command. The controller unit determines and amount of regenerative torque available and compares this value to a determined amount of brake torque requested for determining the control signals to the electric motor/generator and the friction brake system.

  11. Eddy current braking experiment using brake disc from aluminium series of A16061 and A17075

    NASA Astrophysics Data System (ADS)

    Baharom, M. Z.; Nuawi, M. Z.; Priyandoko, G.; Harris, S. M.

    2012-09-01

    The electromagnetic braking using eddy current was studied, focused on two series of aluminium as the brake disc which are A16061 and A17075. This paper presents the comparison for both series in a few varied parameters related to eddy current braking such as air-gap, number of turns and brake disc thickness. Optical tachometer has been used along with PULSE analyzer to capture the speed (rpm) and time (s). The findings shows that the smaller the air-gap, the larger of electromagnet turns and the thicker disc thickness is, will generate higher braking torque to stop the rotational motion of disc brake and give great performance for eddy current braking. Thos parameters that been evaluated also addressed a potential on expanding this knowledge to develop an electromagnetic braking system to replace the conventional braking system.

  12. Preliminary survey report: control technology for brake lining at Northwest Local School District, Cincinnati, Ohio

    SciTech Connect

    Cooper, T.C.; McGlothlin, J.D.; Godbey, F.W.; Sheehy, J.W.; O'Brien, D.M.

    1986-05-01

    A walk-through survey of control technology for reducing asbestos exposure during maintenance and repair of vehicular brakes was conducted at Northwest Local School District, Cincinnati, Ohio in January, 1986. The primary method for controlling and collecting dust during brake servicing was a wet-washing technique and good work practices, ensuring that exposure to hazardous physical or chemical agents was reduced or eliminated. Also available was an enclosed-type brake assembly cleaner designed to be connected to the shop air and a vacuum system. The brake assembly cleaner did not have a viewing port to examine the area being cleaned. The operator had to remove the unit to inspect the cleaned area potentially exposing himself to any dust remaining on the brake shoes or hub. The unit itself was a potential dust source as it was designed to fit 16-inch wheels and did not form a tight seal on the smaller 15-inch wheels of the newer buses. The authors conclude that the wet wash technique is an excellent method for controlling asbestos emissions during brake maintenance. The vacuum brake-assembly cleaner is inadequate and potentially hazardous. An in-depth survey of the wet technique is recommended.

  13. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  14. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  15. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  16. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  17. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  18. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  19. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  20. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (6) Pad and pad holders. Caliper brake pad shall be replaceable and adjustable to engage the braking... caliper assembly. The brake pad material shall be retained in its holder without movement when the bicycle.... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b)...

  1. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles... 49 Transportation 5 2011-10-01 2011-10-01 false Parking brake system. 393.41 Section 393.41...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  2. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  3. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles... 49 Transportation 5 2010-10-01 2010-10-01 false Parking brake system. 393.41 Section 393.41...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  4. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  5. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  6. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  7. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  8. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  9. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  10. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  11. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  12. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  13. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  14. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Single car air brake tests. 232.305 Section 232... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in... single car air brake test on a car when: (1) A car has its brakes cut-out or inoperative when...

  15. Space shuttle wheels and brakes

    NASA Technical Reports Server (NTRS)

    Carsley, R. B.

    1985-01-01

    The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

  16. Electromagnetic braking for Mars spacecraft

    NASA Technical Reports Server (NTRS)

    Holt, A. C.

    1986-01-01

    Aerobraking concepts are being studied to improve performance and cost effectiveness of propulsion systems for Mars landers and Mars interplanetary spacecraft. Access to megawatt power levels (nuclear power coupled to high-storage inductive or capacitive devices) on a manned Mars interplanetary spacecraft may make feasible electromagnetic braking and lift modulation techniques which were previously impractical. Using pulsed microwave and magnetic field technology, potential plasmadynamic braking and hydromagnetic lift modulation techniques have been identified. Entry corridor modulation to reduce loads and heating, to reduce vertical descent rates, and to expand horizontal and lateral landing ranges are possible benefits. In-depth studies are needed to identify specific design concepts for feasibility assessments. Standing wave/plasma sheath interaction techniques appear to be promising. The techniques may require some tailoring of spacecraft external structures and materials. In addition, rapid response guidance and control systems may require the use of structurally embedded sensors coupled to expert systems or to artificial intelligence systems.

  17. Design and Analysis of a Novel Centrifugal Braking Device for a Mechanical Antilock Braking System.

    PubMed

    Yang, Cheng-Ping; Yang, Ming-Shien; Liu, Tyng

    2015-06-01

    A new concept for a mechanical antilock braking system (ABS) with a centrifugal braking device (CBD), termed a centrifugal ABS (C-ABS), is presented and developed in this paper. This new CBD functions as a brake in which the output braking torque adjusts itself depending on the speed of the output rotation. First, the structure and mechanical models of the entire braking system are introduced and established. Second, a numerical computer program for simulating the operation of the system is developed. The characteristics of the system can be easily identified and can be designed with better performance by using this program to studying the effects of different design parameters. Finally, the difference in the braking performance between the C-ABS and the braking system with or without a traditional ABS is discussed. The simulation results indicate that the C-ABS can prevent the wheel from locking even if excessive operating force is provided while still maintaining acceptable braking performance.

  18. Gravity Slides With Magnetic Braking

    NASA Technical Reports Server (NTRS)

    Goodrick, Thomas F.

    1995-01-01

    Slides with magnetic braking enable safe emergency descent from tall buildings, fire-truck ladders, towers, and like. According to concept, slide includes sled that moves along stationary aluminum track tilted against top of building. Sled holds set of permanent magnets at preset small distance from surface of track. Passenger stands on, sits on, or strapped to platform on sled. Release device at top of slide holds sled in place until passenger prepared for descent.

  19. What brakes the Crab pulsar?

    NASA Astrophysics Data System (ADS)

    Čadež, A.; Zampieri, L.; Barbieri, C.; Calvani, M.; Naletto, G.; Barbieri, M.; Ponikvar, D.

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

  20. Mountain Braking Test Venue Study

    DTIC Science & Technology

    2013-12-12

    estimates used in this analysis are based upon engine friction measurements measured by TARDEC on a Caterpillar 3116 Diesel engine as shown in Figure 1...This engine is the predecessor of and similar to the Caterpillar C7 engine used in some MRAP vehicles. The engine braking horsepower based on a...5 UNCLASSIFIED Figure 1: Caterpillar 3116 Diesel Engine Horsepower and Torque Seventy-five to eighty percent of the power absorbed by

  1. Design of a new MR brake mount system considering vertical and horizontal vibrations

    NASA Astrophysics Data System (ADS)

    Do, Xuan Phu; Quoc Hung, Nguyen; Park, Joon Hee; Choi, Seung-Bok

    2014-03-01

    In this paper, a new type of magnetorheological fluid (MRF) mount is proposed. This design is based on the well-known of two modes of MRF such as flow mode and shear mode. These modes are applied in the design which includes two components: MR mount for controlling vertical vibrations, and MR brake for controlling horizontal vibrations. The structure of MR valve is applied in design mount part, while the disk type of structure is employed in design brake part. These structures contribute to the initial requirements such as small structure, high damping force and high braking force. The theoretical analysis for the design is undertaken followed by design optimization using ANSYS ADPL software. The objective functions are concentrated on maximal damping force for MR mount and maximum braking force for MR brake. As traditional design, rubber mount is used in the proposed design for suffering static loads. It has been shown through computer simulation that the initial requirements with high damping force and high braking force have been successfully achieved.

  2. NAC Aftermarket Brake Components Project (Secondary Items)

    DTIC Science & Technology

    2006-09-25

    NAC Aftermarket Brake Components Project (Secondary Items) SAE Paper #2006-01-3192 25 September 2006, Grapevine Version R4 (Final) Report...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE NAC Aftermarket Brake Components Project (Secondary Items) 5a. CONTRACT NUMBER 5b...PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 NAC Aftermarket Brake Components Project By: Leo Miller, USA

  3. Braking, Wheeled Vehicles. Test Operations Procedure (TOP)

    DTIC Science & Technology

    2008-05-20

    are as follows: a. Micrometer calipers (inside, outside, and dial types). b. Surface finish gauges. c. Torque wrench. d. Brake shoe...is imminent. 11. Front Disc Brakes Procedure: Step 1: Visually inspect and measure rotors, calipers , and pads. Equipment needed...4. TITLE AND SUBTITLE Test Operations Procedure (TOP) 2-2-608 Braking , Wheeled Vehicles 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e

  4. PREDICTING RANGES FOR PULSARS' BRAKING INDICES

    SciTech Connect

    Magalhaes, Nadja S.; Miranda, Thaysa A.; Frajuca, Carlos

    2012-08-10

    The theoretical determination of braking indices of pulsars is still an open problem. In this paper we report results of a study concerning such determination based on a modification of the canonical model, which admits that pulsars are rotating magnetic dipoles, and on data from the seven pulsars with known braking indices. In order to test the modified model, we predict ranges for the braking indices of other pulsars.

  5. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    ERIC Educational Resources Information Center

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  6. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  7. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  8. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  9. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  10. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... designs of braking systems, the design process shall include computer modeling or dynamometer simulation... equipment operating speeds. A new simulation is required prior to implementing a change in...

  11. Bidirectional Drive-And-Brake Mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A.

    1991-01-01

    Vehicle that crawls along monorail combines features of both bicycle and railroad handcar. Bidirectional drive-and-brake mechanism includes selectable-pawl-and-ratchet overrunning clutch (drive mechanism) and mating stationary and rotating conical surfaces pressing against each other (brake mechanism). Operates similarly to bicycle drive-and-brake mechanism except limits rotation of sprocket in both directions and brakes at both limits. Conceived for use by astronaut traveling along structure in outer space, concept also applied on Earth to make very small railraod handcars or crawling vehicles for use on large structures, in pipelines under construction, or underwater.

  12. Optimal design of a new multipole bilayer magnetorheological brake

    NASA Astrophysics Data System (ADS)

    Shiao, Yaojung; Ngoc, Nguyen Anh; Lai, Chien-Hung

    2016-11-01

    This article presents a new high-torque multipole bilayer magneto-rheological brake (MRB). This MRB has a unique structural design with multiple electromagnetic poles and multiple media layers of magnetorheological fluid (MRF). The MRB has two rotors located on the outer and inner sides of a six-pole stator, and therefore, it can provide higher torque and a larger torque-to-volume ratio (TVR) than conventional single- or multipole single-layer MRBs can. Moreover, the problem of potential MRF leakage is solved by using cylindrical separator rings around the stator. In this study, first, the structure of the proposed MRB is introduced. An analog magnetic circuit was built for the MRB to investigate the effects of the MRB parameters on the magnetic field intensity of the MRF layers. In addition, a 3D electromagnetic model of the MRB was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. An approximate optimization method was then applied to obtain the optimal geometric dimensions for the major dimensional parameters of the MRB. The MRB was manufactured and tested to validate its torque and dynamic characteristics. The results showed that the proposed MRB exhibited great enhancement of the braking torque and TVR.

  13. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    NASA Astrophysics Data System (ADS)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

  14. Braking index of isolated pulsars

    NASA Astrophysics Data System (ADS)

    Hamil, O.; Stone, J. R.; Urbanec, M.; Urbancová, G.

    2015-03-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities Ω , and their time derivatives that show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of detailed debate, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of Ω . This relation leads to the power law Ω ˙ =-K Ωn where n is called the braking index. The MDR model predicts n exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of n , individually accurate to a few percent or better, in the range 1 braking index within the MDR model. Four microscopic equations of state are employed as input to two different computational codes that solve Einstein's equations numerically, either exactly or using the perturbative Hartle-Thorne method, to calculate the

  15. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  16. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  17. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  18. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  19. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  20. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  1. Constraining the braking indices of magnetars

    NASA Astrophysics Data System (ADS)

    Gao, Z. F.; Li, X.-D.; Wang, N.; Yuan, J. P.; Wang, P.; Peng, Q. H.; Du, Y. J.

    2016-02-01

    Because of the lack of long-term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index n of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of the mean braking indices of eight magnetars with SNRs, and find that they cluster in the range of 1-42. Five magnetars have smaller mean braking indices of 1 < n < 3, and we interpret them within a combination of magneto-dipole radiation and wind-aided braking. The larger mean braking indices of n > 3 for the other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with 1 < n < 3, and the dipolar magnetic field decay rates for the magnetars with n > 3, within the updated magneto-thermal evolution models. Although the constrained range of the magnetars' braking indices is tentative, as a result of the uncertainties in the SNR ages due to distance uncertainties and the unknown conditions of the expanding shells, our method provides an effective way to constrain the magnetars' braking indices if the measurements of the SNR ages are reliable, which can be improved by future observations.

  2. Orbital-Transfer Vehicle With Aerodynamic Braking

    NASA Technical Reports Server (NTRS)

    Scott, C. D.; Nagy, K.; Roberts, B. B.; Ried, R. C.; Kroll, K.; Gamble, J.

    1986-01-01

    Vehicle includes airbrake for deceleration into lower orbit. Report describes vehicle for carrying payloads between low and high orbits around Earth. Vehicle uses thin, upper atmosphere for braking when returning to low orbit. Since less propellant needed than required for full retrorocket braking, vehicle carries larger payload and therefore reduces cost of space transportation.

  3. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  4. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  5. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  6. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal...

  7. Air brake-dynamometer accurately measures torque

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  8. Accelerometer-controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1973-01-01

    Braking system, which employs angular accelerometer to control wheel braking and results in low level of tire slip, has been developed and tested. Tests indicate that system is feasible for operations on surfaces of different slipperinesses. System restricts tire slip and is capable of adapting to rapidly-changing surface conditions.

  9. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) In addition, for commuter...

  10. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) For airplanes required to meet §...

  11. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) In addition, for commuter...

  12. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... determination required by § 23.75, the pressure on the wheel braking system must not exceed the pressure... systems must be designed so that no single probable malfunction or failure will result in a hazardous loss of braking ability or directional control of the airplane. (e) For airplanes required to meet §...

  13. Method and apparatus for electromagnetically braking a motor

    NASA Technical Reports Server (NTRS)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  14. Landing and Braking of Airplanes

    NASA Technical Reports Server (NTRS)

    Breguet, Louis

    1929-01-01

    In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.

  15. Some wear studies on aircraft brake systems

    NASA Technical Reports Server (NTRS)

    Ho, T. L.

    1975-01-01

    An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

  16. Brake performance of core-shell structured carbonyl iron/silica based magnetorheological suspension

    NASA Astrophysics Data System (ADS)

    Nguyen, Phuong-Bac; Do, Xuan-Phu; Jeon, Juncheol; Choi, Seung-Bok; Liu, Ying Dan; Choi, Hyoung Jin

    2014-10-01

    Chemically stable core-shell structured magnetic particles were synthesized by coating soft-magnetic carbonyl iron (CI) microspheres with silica through a sol-gel reaction, and applied as magnetorheological (MR) materials for a specially designed small-sized MR brake. The dynamic yield stress of the MR suspension containing the synthesized particles was also measured using a rotational rheometer under an applied magnetic field. The performance characteristics of the MR brake, including field dependent torque, hysteresis, time and torque tracking control responses were examined. The results showed that with the exception of the settling time, the other response times were faster than those of the pristine CI based MR fluid.

  17. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    ERIC Educational Resources Information Center

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

  18. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... with other than an AB, ABD, ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment of each cab car shall be cleaned, repaired, and tested at intervals in accordance with the following schedule: (1) Every 1,476 days for that portion of the cab car brake system using brake valves that...

  19. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  20. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  1. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  2. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  3. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Breakaway and emergency braking. 393.43 Section... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped...

  4. The Effect of Swirl Braked Grooved Seals on the Stability and the Unbalance Response of a Flexible Rotor

    NASA Astrophysics Data System (ADS)

    Ishimaru, Hidetsugu; Iwatsubo, Takuzo

    Swirl Braked Grooved Seal (SBGS) is an advanced grooved annular seal for rotordynamic stability improvement. SBGS has circumferential or helical grooves in which several swirl brakes are placed. The swirl brakes can prevent the circumferential flow that might generate unstable dynamic fluid force in the seal. The stability and the unbalance response of a simply supported Jeffcott rotor, having a seal near the disk, are analyzed by FEM in which measured rotordynamic coefficients of seals are used. The rotordynamic analysis is performed for 18 different types of seals, including 13 SBGS, 4 conventional grooved seals (1 circumferential and 3 helical), and a smooth seal. Results show that the SBGS with circumferential grooves have high stability and low sensitivity to unbalance. On the other hand, the swirl brakes did not improve either stability or unbalance response for the helically grooved seals.

  5. Modeling regenerative braking and storage for vehicles

    SciTech Connect

    Wicks, F.; Donnelly, K.

    1997-12-31

    The fuel savings benefits of regenerative braking and storage for vehicles are often described but not quantified. For example, the federal government and automobile manufacturers are sponsoring a Program for a New Generation of Vehicles (PGNV) with a goal of obtaining a performance of 80 mpg in a family size car. It is typically suggested that such a vehicle will be a hybrid engine and electric drive with regenerative braking. The authors note that while regenerative braking has the potential of saving fuel, it may also do more harm than good as a result of additional weight, less than ideal charge/discharge efficiency on the batteries or storage flywheels and the limited portion of the entire driving cycle when regenerative braking can be utilized. The authors also noted that if regenerative braking can have a net benefit, it would be on a heavy vehicle such as a municipal bus because of the frequent stop and go requirements for both traffic light and passengers. Thus the authors initiated a study of regenerative braking on such a vehicle. The resulting analysis presented in this paper includes data following municipal buses to define the driving cycle, modeling the bus power requirements from weight, aerodynamics and rolling resistance, and then calculating the fuel saving that could result from an ideal regenerative braking system.

  6. Selection of magnetorheological brake types via optimal design considering maximum torque and constrained volume

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.

    2012-01-01

    This research focuses on optimal design of different types of magnetorheological brakes (MRBs), from which an optimal selection of MRB types is identified. In the optimization, common types of MRB such as disc-type, drum-type, hybrid-types, and T-shaped type are considered. The optimization problem is to find the optimal value of significant geometric dimensions of the MRB that can produce a maximum braking torque. The MRB is constrained in a cylindrical volume of a specific radius and length. After a brief description of the configuration of MRB types, the braking torques of the MRBs are derived based on the Herschel-Bulkley model of the MR fluid. The optimal design of MRBs constrained in a specific cylindrical volume is then analysed. The objective of the optimization is to maximize the braking torque while the torque ratio (the ratio of maximum braking torque and the zero-field friction torque) is constrained to be greater than a certain value. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions of the MRBs. Optimal solutions of MRBs constrained in different volumes are obtained based on the proposed optimization procedure. From the results, discussions on the optimal selection of MRB types depending on constrained volumes are given.

  7. Durability investigation on torque control of a magneto-rheological brake: experimental work

    NASA Astrophysics Data System (ADS)

    Kim, Wan Ho; Park, Jhin Ha; Kim, Gi-Woo; Shin, Cheol Soo; Choi, Seung-Bok

    2017-03-01

    This study experimentally investigates the torque control durability of a disc brake featuring a magneto-rheological (MR) fluid. An appropriate size of MR disc brake is designed based on a mathematical model, and a prototype is manufactured. A small-scale laboratory-scale test bed is then developed using a DC motor, in-line torque sensor, and the MR brake. S45C and S20C steels are inserted into a tapered hole on the surface of the brake disc. After 105 cycles of operation in shear mode, the wear properties of the MR brake are characterized by average surface roughness measurements, scanning electron microscope images, and energy dispersive x-ray spectra. The torque control performances before and after the operation cycles are examined using open-loop control and closed-loop proportional-integral-derivative control. As expected, the control performance degraded after 105 cycles of operation in the open-loop case, but not in the closed-loop case. This aspect is demonstrated by the sinusoidal torque-tacking control performance before and after the operation cycles.

  8. Performance of an aircraft tire under cyclic braking and of a currently operational antiskid braking system

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1972-01-01

    An experimental investigation was conducted to study the performance of an aircraft tire under cyclic braking conditions and to study the performance of a currently operational aircraft antiskid braking system. Dry, damp, and flooded runway surface conditions were used in the investigation. The results indicated that under cyclic braking conditions the braking and cornering-force friction coefficients may be influenced by fluctuations in the vertical load, flexibility in the wheel support, and the spring coupling between the wheel and the tire-pavement interface. The cornering capability was shown to be negligible at wheel slip ratios well below a locked-wheel skid under all test surface conditions. The maximum available brake-force friction coefficient was shown to be dependent upon the runway surface condition, upon velocity, and, for wet runways, upon tire differences. Moderate reductions in vertical load and brake system pressure did not significantly affect the overall wet-runway performance of the tire.

  9. Review of NASA antiskid braking research

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1982-01-01

    NASA antiskid braking system research programs are reviewed. These programs include experimental studies of four antiskid systems on the Langley Landing Loads Track, flights tests with a DC-9 airplane, and computer simulation studies. Results from these research efforts include identification of factors contributing to degraded antiskid performance under adverse weather conditions, tire tread temperature measurements during antiskid braking on dry runway surfaces, and an assessment of the accuracy of various brake pressure-torque computer models. This information should lead to the development of better antiskid systems in the future.

  10. Structure Topology Optimization of Brake Pad in Large- megawatt Wind Turbine Brake Considering Thermal- structural Coupling

    NASA Astrophysics Data System (ADS)

    Zhang, S. F.; Yin, J.; Liu, Y.; Sha, Z. H.; Ma, F. J.

    2016-11-01

    There always exists severe non-uniform wear of brake pad in large-megawatt wind turbine brake during the braking process, which has the brake pad worn out in advance and even threats the safety production of wind turbine. The root cause of this phenomenon is the non-uniform deformation caused by thermal-structural coupling effect between brake pad and disc while braking under the conditions of both high speed and heavy load. For this problem, mathematical model of thermal-structural coupling analysis is built. Based on the topology optimization method of Solid Isotropic Microstructures with Penalization, SIMP, structure topology optimization of brake pad is developed considering the deformation caused by thermal-structural coupling effect. The objective function is the minimum flexibility, and the structure topology optimization model of brake pad is established after indirect thermal- structural coupling analysis. Compared with the optimization result considering non-thermal- structural coupling, the conspicuous influence of thermal effect on brake pad wear and deformation is proven as well as the rationality of taking thermal-structural coupling effect as optimization condition. Reconstructed model is built according to the result, meanwhile analysis for verification is carried out with the same working condition. This study provides theoretical foundation for the design of high-speed and heavy-load brake pad. The new structure may provide design reference for improving the stress condition between brake pad and disc, enhancing the use ratio of friction material and increasing the working performance of large-megawatt wind turbine brake.

  11. Screw-released roller brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  12. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  13. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  14. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  15. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  16. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  17. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... must be in a three point static ground attitude. Horizontal reactions parallel to the ground and... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  18. 14 CFR 29.921 - Rotor brake.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  19. 14 CFR 27.921 - Rotor brake.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  20. Power-Factor Controller With Regenerative Braking

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1982-01-01

    Modified power-factor motor-control circuit operates motor as a phase-controlled generator when load attempts to turn at higher than synchronous speed. An induction motor is required to act at times as a brake. Circuit modification allows power-factor controller to save energy in motoring mode and convert automatically to an induction-generator controller in generating, or braking, mode.

  1. Oscillatory flow braking: inner magnetosphere observations

    NASA Astrophysics Data System (ADS)

    Panov, E. V.; Nakamura, R.; Baumjohann, W.; Angelopoulos, V.

    2013-12-01

    We search for damped oscillatory flow braking events observed by THEMIS/ARTEMIS in the near-Earth plasma sheet when their counterpart in the inner magnetosphere was observed. By comparing the particle and magnetic field data in the two locations we analyze the feedback of the inner magnetosphere to plasma sheet oscillatory flow braking. We discuss the possible role of the oscillatory flow events for plasma injection into the inner magnetosphere.

  2. Method and apparatus for wind turbine braking

    DOEpatents

    Barbu, Corneliu; Teichmann, Ralph; Avagliano, Aaron; Kammer, Leonardo Cesar; Pierce, Kirk Gee; Pesetsky, David Samuel; Gauchel, Peter

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  3. NAC Aftermarket Brake Components Project (Secondary Items)

    DTIC Science & Technology

    2007-02-06

    Supporting the Objective Force – NAC Aftermarket Brake Components Project Version: 06 February 2007 Final UNCLAS: Dist A. Approved for public...release NAC Aftermarket Brake Components Project (Secondary Items) Version: 06 February 2007 Final UNCLAS: Dist A. Approved for public release Leo Miller...Technology Insertion Project Officer (TIPO) US Army National Automotive Center ( NAC ) Warren, MI Report Documentation Page Form ApprovedOMB No. 0704

  4. NAC Off-Vehicle Brake Testing Project

    DTIC Science & Technology

    2007-05-01

    Supporting the Objective Force – NAC Off-vehicle Brake Testing Project -Version: 01 May 2007 FinalR1 UNCLAS: Dist A. Approved for public release NAC ...Project Officer (TIPO) US Army National Automotive Center ( NAC ) Warren, MI Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden... NAC Off-vehicle Brake Testing Project 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Miller, Leo 5d. PROJECT NUMBER

  5. 77 FR 46633 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... Highway Traffic Safety Administration NPRM Notice of Proposed Rulemaking OOS out of service SAE Society of... Engineers (SAE) (now known as SAE International) developed International Recommended Practice J1817 (SAE... brake actuator. The 2001 revision of SAE J1817 includes tables listing recommended values for...

  6. 76 FR 54721 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... National Highway Traffic Safety Administration. NPRM Notice of Proposed Rulemaking. OOS out of service. SAE... brakes should be readjusted. Subsequently, in June 1991, the Society of Automotive Engineers (SAE) developed International Recommended Practice J1817 (SAE J1817) to provide a marking system...

  7. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... train from the propulsion motor(s)) does not apply any electromotive force to the propulsion motor(s). Any electromotive force that is applied to the propulsion motor(s) automatically remains in effect... service brakes also performs the following test series. Conduct 10 stopping tests from a speed of 100...

  8. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... train from the propulsion motor(s)) does not apply any electromotive force to the propulsion motor(s). Any electromotive force that is applied to the propulsion motor(s) automatically remains in effect... service brakes also performs the following test series. Conduct 10 stopping tests from a speed of 100...

  9. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... train from the propulsion motor(s)) does not apply any electromotive force to the propulsion motor(s). Any electromotive force that is applied to the propulsion motor(s) automatically remains in effect... service brakes also performs the following test series. Conduct 10 stopping tests from a speed of 100...

  10. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... train from the propulsion motor(s)) does not apply any electromotive force to the propulsion motor(s). Any electromotive force that is applied to the propulsion motor(s) automatically remains in effect... service brakes also performs the following test series. Conduct 10 stopping tests from a speed of 100...

  11. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... train from the propulsion motor(s)) does not apply any electromotive force to the propulsion motor(s). Any electromotive force that is applied to the propulsion motor(s) automatically remains in effect... service brakes also performs the following test series. Conduct 10 stopping tests from a speed of 100...

  12. Brake for counter rotating bladed members

    SciTech Connect

    Cedoz, R.W.

    1987-02-10

    This patent describes a propulsion system including a gas turbine engine having an output shaft and a gear drive having a planetary gear set with a first element connected to the engine output shaft and a second element connected to a first bladed member and a third element connected to a second bladed member whereby the first and second bladed members are rotated in opposite directions by the output shaft. A brake is described comprising, a first transfer shaft supported on a stationary housing for rotation about an axis of the latter, a second transfer shaft supported on the stationary housing for rotation about the axis, gear means between one of the counter rotating bladed members and the first transfer shaft and gear means between the other of the counter rotating bladed members and the second transfer shaft. The brake also includes a selectively operable brake actuator on the housing movable between an extended position and a retracted position, and friction means between the brake actuator and each of first and second transfer shafts operative in the extended position of the brake actuator to simultaneously frictionally retard rotation of each of the first and the second transfer shafts whereby each of the counter rotating bladed members is simultaneously braked.

  13. Consideration of Materials for Aircraft Brakes

    NASA Technical Reports Server (NTRS)

    Peterson, M. B.; Ho, T.

    1972-01-01

    An exploratory investigation was conducted concerning materials and their properties for use in aircraft brakes. Primary consideration was given to the heat dissipation and the frictional behavior of materials. Used brake pads and rotors were analyzed as part of the investigation. A simple analysis was conducted in order to determine the most significant factors which affect surface temperatures. It was found that where size and weight restrictions are necessary, the specific heat of the material, and maintaining uniform contact area are the most important factors. A criterion was suggested for optimum sizing of the brake disks. Bench friction tests were run with brake materials. It was found that there is considerable friction variation due to the formation and removal of surface oxide films. Other causes of friction variations are surface softening and melting. The friction behavior at high temperature was found to be more characteristic of the steel surface rather than the copper brake material. It is concluded that improved brake materials are feasible.

  14. Automated visual inspection of brake shoe wear

    NASA Astrophysics Data System (ADS)

    Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

    2015-10-01

    With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

  15. 75 FR 63042 - Airworthiness Directives; Fokker Services B.V. Model F.28 Mark 0070 and 0100 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-14

    ... disconnected) brake QD coupling. Further investigation of the service experience files at Fokker Services... QD [quick- disconnect] couplings loosened and/or disconnected during operation. In a few cases... hot brakes. Loosened couplings may cause a hydraulic leak with the risk of a brake fire....

  16. Braking Index of GEMINGA Pulsar

    NASA Astrophysics Data System (ADS)

    Ramanamurthy, P. V.; Mattox, J. R.; EGRET Science Team

    1993-12-01

    The pulsar Geminga, also known as 2CG195+04, IE0630+178 and the faint star G", is a remarkable object in the sense that its energy output is almost all in high energy gamma rays. The pulsar elements of this 237 ms pulsar as given by various authors are surveyed. The braking index, $ n = ftimes ddot f / (dot f)(2) as obtained from the elements given by any one group (Hermsen et al. 1992; Bertsch et al. 1992) based on their own data set appears to be too high or has a very large upper limit compared with 3, the value expected for magnetic dipole radiation. This is largely due to the uncertainty in the value of \\ddot f. It is difficult to carry the absolute phase from one set of observations to another for a variety of reasons. Rather than fitting a polynomial in elapsed time to the event phases over different data sets, we have taken a different approach to determine \\ddot f. Hermsen et al. (1992) and Mattox et al. (1993) have determined f and \\dot f from COS-B and EGRET data respectively at two widely separated epochs. Assuming that there were no glitches, we obtained \\ddot f by dividing the difference in \\dot f values at the two epochs by the time difference between the two epochs; the resulting value of \\ddot f is (4 \\pm 2) times 10^{-26} s^{-3} . Combining this with the f and \\dot f values we obtained a value of (4.5 \\pm 2.3) for the braking index. This value agrees well with the expected. With more observations of Geminga scheduled for the Compton GRO, we expect that the error in \\dot f and consequently the errors in \\ddot f and n$ will decrease further in future. \\leftline{Bertsch et al. (1992) Nature, 357, 306} \\leftline{Hermsen et al. (1992) IAU Circular # 5541} \\leftline{Mattox et al. Proc. 2nd Compton Symp., (September, 1993), College} \\leftline{\\quad Park, Md., U.S.A.}

  17. Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization

    NASA Astrophysics Data System (ADS)

    Lü, Hui; Yu, Dejie

    2014-12-01

    An uncertain optimization method for brake squeal reduction of vehicle disc brake system with interval parameters is presented in this paper. In the proposed method, the parameters of frictional coefficient, material properties and the thicknesses of wearing components are treated as uncertain parameters, which are described as interval variables. Attention is focused on the stability analysis of a brake system in squeal, and the stability of brake system is investigated via the complex eigenvalue analysis (CEA) method. The dominant unstable mode is extracted by performing CEA based on a linear finite element (FE) model, and the negative damping ratio corresponding to the dominant unstable mode is selected as the indicator of instability. The response surface method (RSM) is applied to approximate the implicit relationship between the unstable mode and the system parameters. A reliability-based optimization model for improving the stability of the vehicle disc brake system with interval parameters is constructed based on RSM, interval analysis and reliability analysis. The Genetic Algorithm is used to get the optimal values of design parameters from the optimization model. The stability analysis and optimization of a disc brake system are carried out, and the results show that brake squeal propensity can be reduced by using stiffer back plates. The proposed approach can be used to improve the stability of the vehicle disc brake system with uncertain parameters effectively.

  18. 49 CFR 236.508 - Interference with application of brakes by means of brake valve.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS..., AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake valve. The automatic train stop, train control,...

  19. 49 CFR 236.508 - Interference with application of brakes by means of brake valve.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS..., AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake valve. The automatic train stop, train control,...

  20. 49 CFR 236.508 - Interference with application of brakes by means of brake valve.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS..., AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake valve. The automatic train stop, train control,...

  1. 49 CFR 236.508 - Interference with application of brakes by means of brake valve.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS..., AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake valve. The automatic train stop, train control,...

  2. 49 CFR 236.508 - Interference with application of brakes by means of brake valve.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interference with application of brakes by means of brake valve. 236.508 Section 236.508 Transportation Other Regulations Relating to Transportation..., AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards §...

  3. Adaptive controller for regenerative and friction braking system

    DOEpatents

    Davis, R.I.

    1990-10-16

    A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

  4. Recent studies of tire braking performance. [for aircraft

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.; Leland, T. J. W.

    1973-01-01

    The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

  5. Adaptive controller for regenerative and friction braking system

    SciTech Connect

    Davis, Roy I.

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  6. Braking Index of Isolated Pulsars

    NASA Astrophysics Data System (ADS)

    Hamil, Oliver; Stone, Jirina; Urbanec, Martin; Urbancova, Gabriela

    2015-04-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities Ω, and their time derivatives which show unambiguously that the pulsars are slowing down. The exact mechanism of the spin-down is a question of debate in detail, but the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR). The energy loss by a rotating pulsar is proportional to a model dependent power of Ω. This relation leads to the power law Ω˙ = -K Ωn where n is called the braking index, equal to the ratio (ΩΩ̈)/ Ω˙2 . The simple MDR model predicts the value of n = 3, but observations of isolated pulsars provide rather precise values of n, individually accurate to a few percent or better, in the range 1 < n < 2.8, which is consistently less than the predictions of the MDR model. In this work, we study the dynamical limits of the MDR model as a function of angular velocity. The effects of variation in the rest mass, the moment of inertia, and the dependence on a realistic Equation of State of the rotating star are considered. Furthermore, we introduce a simulated superfluid effect by which the angular momentum of the core is eliminated from the calculation.

  7. Electromagnetic brake/clutch device

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1994-01-01

    An electromagnetic brake/clutch device includes a drive shaft supported by at least one bearing for transmitting torque, a housing, affixed to prevent its rotation, surrounding the drive shaft, and an electromagnetically activated device within the housing to selectively prevent and allow rotation of the drive shaft. The electromagnetically activated device includes a plurality of cammed rollers to prevent counter-clockwise rotation of the drive shaft. The drive shaft includes a circumferential disk and the housing includes a reaction ring for engagement with the plurality of cammed rollers. The plurality of cammed rollers are released from engagement with the circumferential disk and the reaction ring by a plurality of tripping mechanisms within the housing. The tripping action uses the locking force to act as a release force merely by changing the boundary conditions of the roller interface angles. The tripping mechanisms include trippers for disengaging the plurality of cammed rollers and an anvil shaped portion for providing lateral movement of the trippers. The plurality of cammed rollers is preloaded to engagement with the circumferential disk and reaction ring by a spring, and is located with respect to an adjacent tripping mechanism with another spring.

  8. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  9. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  10. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  11. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  12. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electrical integrity test of the dynamic brake to determine if electrical current is being received at the... an electrical integrity test of the dynamic brake to determine if electrical current is...

  13. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.493 Braked...

  14. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.493 Braked...

  15. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.493 Braked...

  16. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.493 Braked...

  17. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.493 Braked...

  18. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.493 Braked...

  19. 1. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE SHOES AND BRAKE HANDLE, LOOKING NORTH - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  20. 2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE SHOES, BRAKE HANDLE, AND REDUCTION GEARS, LOOKING SOUTHWEST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  1. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  2. 49 CFR 393.49 - Control valves for brakes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Control valves for brakes. 393.49 Section 393.49 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Brakes § 393.49 Control valves for brakes. (a) General rule. Except as...

  3. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  4. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  5. The Scaling of Information to Action in Visually Guided Braking

    ERIC Educational Resources Information Center

    Fajen, Brett R.

    2005-01-01

    Braking to avoid a collision can be controlled by keeping the deceleration required to stop (i.e., ideal deceleration) in the "safe" region below maximum deceleration, but maximum deceleration is not optically specified and can vary as conditions change. When brake strength was manipulated between participants using a simulated braking task, the…

  6. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Emergency braking for electric hoists. 57.19017... Hoisting Hoists § 57.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  7. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Emergency braking for electric hoists. 56.19017... Hoisting Hoists § 56.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  8. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  9. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  10. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  11. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  12. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  13. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  14. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  15. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  16. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  17. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  18. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  19. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Emergency braking for electric hoists. 57.19017... Hoisting Hoists § 57.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  20. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Emergency braking for electric hoists. 56.19017... Hoisting Hoists § 56.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  1. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Emergency braking for electric hoists. 56.19017... Hoisting Hoists § 56.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  2. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Emergency braking for electric hoists. 57.19017... Hoisting Hoists § 57.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  3. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Emergency braking for electric hoists. 57.19017... Hoisting Hoists § 57.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  4. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Emergency braking for electric hoists. 56.19017... Hoisting Hoists § 56.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  5. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Emergency braking for electric hoists. 57.19017... Hoisting Hoists § 57.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  6. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Emergency braking for electric hoists. 56.19017... Hoisting Hoists § 56.19017 Emergency braking for electric hoists. Each electric hoist shall be equipped with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  7. 49 CFR 396.25 - Qualifications of brake inspectors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Qualifications of brake inspectors. 396.25 Section..., REPAIR, AND MAINTENANCE § 396.25 Qualifications of brake inspectors. (a) Motor carriers and intermodal... require or permit any employee who does not meet the minimum brake inspector qualifications of...

  8. 49 CFR 396.25 - Qualifications of brake inspectors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Qualifications of brake inspectors. 396.25 Section..., REPAIR, AND MAINTENANCE § 396.25 Qualifications of brake inspectors. (a) Motor carriers and intermodal... require or permit any employee who does not meet the minimum brake inspector qualifications of...

  9. 49 CFR 396.25 - Qualifications of brake inspectors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Qualifications of brake inspectors. 396.25 Section..., REPAIR, AND MAINTENANCE § 396.25 Qualifications of brake inspectors. (a) Motor carriers and intermodal... require or permit any employee who does not meet the minimum brake inspector qualifications of...

  10. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... operable by the driver except upon application of the control that activates the braking system. The device... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  11. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... operable by the driver except upon application of the control that activates the braking system. The device... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  12. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Braking system. 75.1404-1 Section 75.1404-1... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for...

  13. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Braking system. 75.1404-1 Section 75.1404-1... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for...

  14. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... operable by the driver except upon application of the control that activates the braking system. The device... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  15. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... operable by the driver except upon application of the control that activates the braking system. The device... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  16. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Braking system. 75.1404-1 Section 75.1404-1... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for...

  17. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Braking system. 75.1404-1 Section 75.1404-1... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for...

  18. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Braking system. 75.1404-1 Section 75.1404-1... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for...

  19. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... operable by the driver except upon application of the control that activates the braking system. The device... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  20. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inclined conveyors: backstops or brakes. 56... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  1. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inclined conveyors: backstops or brakes. 56... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  2. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inclined conveyors: backstops or brakes. 57... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  3. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inclined conveyors: backstops or brakes. 57... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  4. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inclined conveyors: backstops or brakes. 56... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  5. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inclined conveyors: backstops or brakes. 57... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  6. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inclined conveyors: backstops or brakes. 56... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  7. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inclined conveyors: backstops or brakes. 56... Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  8. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inclined conveyors: backstops or brakes. 57... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  9. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inclined conveyors: backstops or brakes. 57... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14113 Inclined conveyors: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  10. Magnetic braking in weakly ionized media

    NASA Technical Reports Server (NTRS)

    Konigl, Arieh

    1987-01-01

    The combined magnetic braking-ambipolar diffusion problem in weakly ionized, rigidly rotating disks is studied. An analytical solution is presented for a disk whose angular velocity and magnetic yield vectors are aligned with the symmetry axis, illustrating the effects of the relative azimuthal drift of neutrals and ions. The effects of radial drift are added, commenting on the ratio of the characteristic ambipolar diffusion and magnetic braking time scales in high-mass and low-mass disks. A numerical calculation is used to show the combined action of these two processes.

  11. The UKNEQAS scheme for cerebrospinal fluid haem pigments: a paradigm for service improvement.

    PubMed

    Beetham, Robert; Egner, William; Patel, Dina

    2011-11-01

    We describe the programme of an established External Quality Assurance (EQA) provider and a Specialist Advisory Group (SAG) to develop a successful EQA scheme for cerebrospinal fluid (CSF) haem pigments as an example of a professionally led, unfunded initiative with the real potential to benefit patients. Within three years, we had assured sample stability, stoichiometry, and published best practice guidelines, enabling both analytical results and interpretation to be assessed and reported with an educative summary of the desired responses. Misclassification scoring of analysis and interpretation was introduced. Following audit, guidelines were modified and republished. The outcomes were as follows: Participant numbers increased from 63 at inception to 150 10 years later; The percentage of participants using visual inspection, a poor practice indicator, decreased from 27% to less than 1%; In all, 94-100% of participants consistently detected minor increases in bilirubin over the last four years of the scheme; More than 93% of participants were able to interpret analytical results linked to straightforward clinical scenarios; Misclassification scoring demonstrated that more complex scenarios repeatedly posed problems and is the next challenge to address. Scheme success is attributed to the experience of the operator and the formation of a voluntary expert advisory group, with both concerned to advance science and patient safety and thus contribute unpaid time and effort in order to succeed. In times of fiscal constraint, such resource may not be so readily available, yet is a vital part of continuous quality improvement for the benefit of patients.

  12. The design of aircraft brake systems, employing cooling to increase brake life

    NASA Technical Reports Server (NTRS)

    Scaringe, R. P.; Ho, T. L.; Peterson, M. B.

    1975-01-01

    A research program was initiated to determine the feasibility of using cooling to increase brake life. An air cooling scheme was proposed, constructed and tested with various designs. Straight and curved slotting of the friction material was tested. A water cooling technique, similar to the air cooling procedure, was evaluated on a curved slotted rotor. Also investigated was the possibility of using a phase-change material within the rotor to absorb heat during braking. Various phase-changing materials were tabulated and a 50%, (by weight) LiF - BeF2 mixing was chosen. It was shown that corrosion was not a problem with this mixture. A preliminary design was evaluated on an actual brake. Results showed that significant improvements in lowering the surface temperature of the brake occurred when air or water cooling was used in conjunction with curved slotted rotors.

  13. REPORT on the TRUCK BRAKE LINING WORKSHOP and FLEET OPERATORS' SURVEY

    SciTech Connect

    Blau, P.J.

    2003-02-03

    The report summarizes what transpired during brake linings-related workshop held at the Fall 2003 meeting of the Technology and Maintenance Council (TMC) in Charlotte, NC. The title of the workshop was ''Developing a Useful Friction Material Rating System''. It was organized by a team consisting of Peter Blau (Oak Ridge National Laboratory), Jim Britell (National Highway Traffic Safety Administration), and Jim Lawrence (Motor and Equipment Manufacturers Association). The workshop was held under the auspices of TMC Task Force S6 (Chassis), chaired by Joseph Stianche (Sanderson Farms, Inc.). Six invited speakers during the morning session provided varied perspectives on testing and rating aftermarket automotive and truck brake linings. They were: James R. Clark, Chief Engineer, Foundation Brakes and Wheel Equipment, Dana Corporation, Spicer Heavy Axle and Brake Division; Charles W. Greening, Jr, President, Greening Test Labs; Tim Duncan, General Manager, Link Testing Services;Dennis J. McNichol, President, Dennis NationaLease; Jim Fajerski, Business Manager, OE Sales and Applications Engineering, Federal Mogul Corporation; and Peter J. Blau, Senior Materials Development Engineer, Oak Ridge National Laboratory. The afternoon break-out sessions addressed nine questions concerning such issues as: ''Should the federal government regulate aftermarket lining quality?''; ''How many operators use RP 628, and if so, what's good or bad about it?''; and ''Would there be any value to you of a vocation-specific rating system?'' The opinions of each discussion group, consisting of 7-9 participants, were reported and consolidated in summary findings on each question. Some questions produced a greater degree of agreement than others. In general, the industry seems eager for more information that would allow those who are responsible for maintaining truck brakes to make better, more informed choices on aftermarket linings. A written fleet operator survey was also conducted during the

  14. Calculations enable optimum design of magnetic brake

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G.

    1966-01-01

    Mathematical analysis and computations determine optimum magnetic coil configurations for a magnetic brake which controllably decelerates a free falling load to a soft stop. Calculations on unconventionally wound coils determine the required parameters for the desired deceleration with minimum electrical energy supplied to the stationary coil.

  15. A High Braking Index for a Pulsar

    NASA Astrophysics Data System (ADS)

    Archibald, R. F.; Gotthelf, E. V.; Ferdman, R. D.; Kaspi, V. M.; Guillot, S.; Harrison, F. A.; Keane, E. F.; Pivovaroff, M. J.; Stern, D.; Tendulkar, S. P.; Tomsick, J. A.

    2016-03-01

    We present a phase-coherent timing solution for PSR J1640-4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640-4631 to be n = 3.15 ± 0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than three are allowed in nature; hence, other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3σ upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  16. Braking mechanism is self actuating and bidirectional

    NASA Technical Reports Server (NTRS)

    Pizzo, J.

    1966-01-01

    Mechanism automatically applies a braking action on a moving item, in either direction of motion, immediately upon removal of the driving force and with no human operator involvement. This device would be useful wherever free movement is undesirable after an object has been guided into a precise position.

  17. Wind-Tunnel Investigations of Diving Brakes

    NASA Technical Reports Server (NTRS)

    Fucha, D.

    1942-01-01

    Unduly high diving speeds can be effectively controlled by diving brakes but their employment involves at the same time a number of disagreeable features: namely, rotation of zero lift direction, variation of diviving moment, and, the creation of a potent dead air region.

  18. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment with... surface-operated equipment at underground mines when an MSHA inspector has reasonable cause to...

  19. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment with... surface-operated equipment at underground mines when an MSHA inspector has reasonable cause to...

  20. A HIGH BRAKING INDEX FOR A PULSAR

    SciTech Connect

    Archibald, R. F.; Ferdman, R. D.; Kaspi, V. M.; Tendulkar, S. P.; Gotthelf, E. V.; Guillot, S.; Harrison, F. A.; Keane, E. F.; Pivovaroff, M. J.; Stern, D.; Tomsick, J. A.

    2016-03-01

    We present a phase-coherent timing solution for PSR J1640–4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640–4631 to be n = 3.15 ± 0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than three are allowed in nature; hence, other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3σ upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  1. Experimental investigation of an accelerometer controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1972-01-01

    An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

  2. Pedestrian injury mitigation by autonomous braking.

    PubMed

    Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

    2010-11-01

    The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness.

  3. 75 FR 27961 - Airworthiness Directives; Fokker Services B.V. Model F.28 Mark 0070 and 0100 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    ... necessarily disconnected) brake QD coupling. Further investigation of the service experience files at Fokker... QD [quick- disconnect] couplings loosened and/or disconnected during operation. In a few cases... hot brakes. Loosened couplings may cause a hydraulic leak with the risk of a brake fire....

  4. Braking hazards of golf cars and low speed vehicles.

    PubMed

    Seluga, K J; Ojalvo, I U

    2006-11-01

    Research and analysis of braking issues for golf cars and other low speed vehicles (LSVs) are reported in this study. It is shown that many such vehicles only provide braking for their rear wheels, which can lead to a driver losing control during travel on typical steep downgrades. The braking performance of a golf car equipped with brakes on two or four wheels was analyzed to determine the effects of two and four wheel brake designs on braking efficiency and vehicle yaw stability. Besides reducing braking efficiency, it is demonstrated that installing brakes on only the rear wheels can lead to directional instability (fishtailing) and rollover when the rear wheels are braked until skidding occurs. The nonexistence of golf course standards and the inadequacy of golf car and LSV standards are noted and a connection between this and the comparatively high level of accidents with such vehicles is inferred. Based on these results, it is advisable to install brakes on all four wheels of golf cars and LSVs. In addition, new safety standards should be considered to reduce the occurrence of golf car accidents on steep downhill slopes.

  5. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inspected for leaks in the brake system. (n) Securement of unattended equipment. A train's air brake shall... brakes. (f) Each car in a train shall have its air brakes in effective operating condition unless the car is being moved for repairs in accordance with §§ 232.15 and 232.609. The air brakes on a car are...

  6. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... inspected for leaks in the brake system. (n) Securement of unattended equipment. A train's air brake shall... brakes. (f) Each car in a train shall have its air brakes in effective operating condition unless the car is being moved for repairs in accordance with §§ 232.15 and 232.609. The air brakes on a car are...

  7. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... inspected for leaks in the brake system. (n) Securement of unattended equipment. A train's air brake shall... brakes. (f) Each car in a train shall have its air brakes in effective operating condition unless the car is being moved for repairs in accordance with §§ 232.15 and 232.609. The air brakes on a car are...

  8. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... passenger equipment containing a power brake defect at the time a Class I or IA brake test is performed... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its consist passenger equipment containing a power brake defect at the time that a Class I or IA brake...

  9. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXVI, I--CATERPILLAR LUBRICATION SYSTEMS AND COMPONENTS, II--LEARNING ABOUT BRAKES (PART I).

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE FUNCTIONS OF DIESEL ENGINE LUBRICATION SYSTEMS AND COMPONENTS AND THE PRINCIPLES OF OPERATION OF BRAKE SYSTEMS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) THE NEED FOR OIL, (2) SERVICE CLASSIFICATION OF OILS, (3) CATERPILLAR LUBRICATION SYSTEM COMPONENTS (4)…

  10. Debiasing overoptimistic beliefs about braking capacity.

    PubMed

    Svenson, Ola; Eriksson, Gabriella; Mertz, C K

    2013-09-01

    We investigated, using questionnaires, different strategies for removing drivers' overoptimism (Svenson et al., 2012a) about how fast their speed could be decreased when they were speeding compared with braking at the speed limit speed. Three different learning groups and a control group made collision speed judgments. The first learning group had the distance a car travels during a driver's reaction time for each problem. The second group had this information and also feedback after each judgment (correct speed). The third group judged collision speed but also braking distance and received correct facts after each problem. The control group had no information at all about reaction time and the distance traveled during that time. The results suggested the following rank order from poor to improved performance: control, group 1, group 3 and group 2 indicating that information about distance driven during a driver's reaction time improved collision speed judgments and that adding stopping distance information did not add to this improvement.

  11. Wind turbine trailing edge aerodynamic brakes

    SciTech Connect

    Migliore, P G; Miller, L S; Quandt, G A

    1995-04-01

    Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).

  12. Plasma Braking Due to External Magnetic Perturbations

    NASA Astrophysics Data System (ADS)

    Frassinetti, L.; Olofsson, Kejo; Brunsell, P. R.; Khan, M. W. M.; Drake, J. R.

    2010-11-01

    The RFP EXTRAP T2R is equipped with a comprehensive active feedback system (128 active saddle coils in the full-coverage array) and active control of both resonant and non-resonant MHD modes has been demonstrated. The feedback algorithms, based on modern control methodology such as reference mode tracking (both amplitude and phase), are a useful tool to improve the ``state of the art'' of the MHD mode control. But this tool can be used also to improve the understanding and the characterization of other phenomena such as the ELM mitigation with a resonant magnetic perturbation or the plasma viscosity. The present work studies plasma and mode braking due to static RMPs. Results show that a static RMP produces a global braking of the flow profile. The study of the effect of RMPs characterized by different helicities will also give information on the plasma viscosity profile. Experimental results are finally compared to theoretical models.

  13. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... Distance—Feet 0-36000 34 38 43 48 53 59 64 70 76 83 89 36000-70000 41 46 52 58 62 70 76 83 90 97 104 70000...-400000 59 66 74 81 89 97 105 114 123 132 141 Over 400000 63 71 78 86 94 103 111 120 129 139 148...

  14. Optimization of vehicle accelerator-brake pedal foot travel time.

    PubMed

    Glass, S W; Suggs, C W

    1977-12-01

    This study was directed towards reducing the lag time between stimulus and incidence of braking. The effect of the relative vertical heights of the brake and accelerator pedals on foot travel time was the subject of the first part of the investigation. In the second part, two new pedal designs in which the accelerator was mounted directly on the brake pedal were evaluated. A significant reduction in foot travel time of approximately 12.5% was realised by locating the accelerator pedal 25-50 mm (1-2 in) higher than the brake pedal. Mounting of the accelerator pedal adjacent to or directly on the brake pedal allowed reductions in braking lag time of 46% to 74%.

  15. A high performance pneumatic braking system for heavy vehicles

    NASA Astrophysics Data System (ADS)

    Miller, Jonathan I.; Cebon, David

    2010-12-01

    Current research into reducing actuator delays in pneumatic brake systems is opening the door for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, these algorithms require the knowledge of variables that are impractical to measure directly. This paper introduces a sliding mode braking force observer to support a sliding mode controller for air-braked heavy vehicles. The performance of the observer is examined through simulations and field testing of an articulated heavy vehicle. The observer operated robustly during single-wheel vehicle simulations, and provided reasonable estimates of surface friction from test data. The effect of brake gain errors on the controller and observer are illustrated, and a recursive least squares estimator is derived for the brake gain. The estimator converged within 0.3 s in simulations and vehicle trials.

  16. Squeal noise in simple numerical brake models

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.

    2015-09-01

    Since the early 1920s, automotive disc brake squeal has caused warranty issues and customer dissatisfaction. Despite a good deal of progress achieved, predicting brake squeal propensity is as difficult as ever as not all mechanisms and interactions are known owing to their highly fugitive complex nature. In recent years, research has been focused on the prediction of unstable vibration modes by the complex eigenvalue analysis (CEA) for the mode-coupling type of instability. There has been very limited consideration given to the calculation of the acoustic radiation properties due to friction contact between a pad and a rotor. Recent analyses using a forced response analysis with harmonic contact pressure excitation indicates negative dissipated energy at some pad eigenfrequencies predicted to be stable by the CEA. A transient nonlinear time domain analysis with no external excitation indicates that squeal could develop at these eigenfrequencies. Here, the acoustic radiation characteristics of those pad modes are determined by analysing the acoustic power levels and radiation efficiencies of simplified brake models in the form of a pad rubbing on a plate or on a disc using the acoustic boundary element method based on velocities extracted from the forced response analysis. Results show that unstable pad modes trigger unstable disc vibrations resulting in instantaneous mode squeal similar to those observed experimentally. Changes in the radiation efficiency with pressure variations are smaller than those with friction coefficient variations and are caused by the phase difference of the velocities out-of-plane vibration between the pad and the disc.

  17. Longitudinal wheel slip during ABS braking

    NASA Astrophysics Data System (ADS)

    Hartikainen, Lassi; Petry, Frank; Westermann, Stephan

    2015-02-01

    Anti-lock braking system (ABS) braking tests with two subcompact passenger cars were performed on dry and wet asphalt, as well as on snow and ice surfaces. The operating conditions of the tyres in terms of wheel slip were evaluated using histograms of the wheel slip data. The results showed different average slip levels for different road surfaces. It was also found that changes in the tyre tread stiffness affected the slip operating range through a modification of the slip value at which the maximum longitudinal force is achieved. Variation of the tyre footprint length through modifications in the inflation pressure affected the slip operating range as well. Differences in the slip distribution between vehicles with different brake controllers were also observed. The changes in slip operating range in turn modified the relative local sliding speeds between the tyre and the road. The results highlight the importance of the ABS controller's ability to adapt to changing slip-force characteristics of tyres and provide estimates of the magnitude of the effects of different tyre and road operating conditions.

  18. Tau as a Potential Control Variable for Visually Guided Braking

    ERIC Educational Resources Information Center

    Rock, Paul B.; Harris, Mike G.

    2006-01-01

    D. N. Lee (1976) described a braking strategy based on optical expansion in which the driver brakes so that the target's time-to-contact declines around a constant slope in the range -0.5 less than or equal to tau less than 0. The present results from a series of braking simulations confirm and extend earlier reports (E. H. Yilmaz & W. H. Warren,…

  19. A proposal for dynamic calibration of brake tester

    NASA Astrophysics Data System (ADS)

    Ferreira, Paulo L. S.; Couto, Paulo R. G.; Cabral, Luiz C.; Reis, Ronaldo G.; Zillner, Marcos

    2015-10-01

    In Brazil there are about 400 security inspection lines carrier operating in Inspection Bodies accredited by Cgcre Inmetro [1]. The equipment in this proposal is a Brake Tester that measure vehicle braking forces and it is a component of an inspection line. This paper proposes a dynamic Brake Tester calibration using a reference torque transducer. This article can also be the basis for future discussions of the revised standard manufacturing of vehicle inspection line according to ABNT NBR 14040 [2].

  20. Status of recent aircraft braking and cornering research

    NASA Technical Reports Server (NTRS)

    Stubbs, S. M.; Tanner, J. A.

    1976-01-01

    The sources of degraded performance which sometimes occurs under adverse runway conditions, are investigated to obtain data necessary to the development of more advanced systems, in an effort to insure safe ground handling operations under all-weather conditions. Tire-to-ground friction characteristics are determined under braking conditions which closely resemble those of airplanes under heavy braking. Braking data from single-wheel landing loads track tests are related with those available from full-scale flight tests.

  1. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    PubMed

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  2. Aerodynamic braking of high speed ground transportation vehicles.

    NASA Technical Reports Server (NTRS)

    Marte, J. E.; Marko, W. J.

    1973-01-01

    The drag effectiveness of aerodynamic brakes arranged in series on a train-like vehicle was investigated. Fixed- and moving-model testing techniques were used in order to determine the importance of proper vehicle-ground interference simulation. Fixed-model tests were carried out on a sting-mounted model: alone; with a fixed ground plane; and in proximity to an image model. Moving-model tests were conducted in a vertical slide-wire facility with and without a ground plane. Results from investigations of one brake configuration are presented which show the effect of the number of brakes in the set and of spacing between brakes.

  3. 25. DETAIL SHOWING BRAKING MECHANISM FOR TRAIN, NOTE HOT RAIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. DETAIL SHOWING BRAKING MECHANISM FOR TRAIN, NOTE HOT RAIL ON LEFT - Jefferson National Expansion Memorial Arch, Mississippi River between Washington & Poplar Streets, Saint Louis, Independent City, MO

  4. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    NASA Astrophysics Data System (ADS)

    Minh, Vu Trieu; Oamen, Godwin; Vassiljeva, Kristina; Teder, Leo

    2016-11-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. This paper provides educational theories and practices on the design of control for system dynamics.

  5. Copper leaching from brake wear debris in standard extraction solutions.

    PubMed

    Hur, Jin; Yim, Soobin; Schlautman, Mark A

    2003-10-01

    Quantification of the copper content of and copper leaching from a disc brake wear debris sample was performed using microwave-assisted acid digestion, the Federal Toxicity Characteristic Leaching Procedure (TCLP), and the State of California Waste Extraction Test (WET). The brake wear debris tested was a composite sample obtained from a brake dynamometer test of one brake pad source material. Comparative digestion studies demonstrated that a modified aqua regia matrix (HNO3:HCl:H2O2 = 1:3:0.5) optimized the digestion effectiveness for determining the total copper content in the brake wear debris. No significant sample heterogeneity within the brake wear debris was observed, based on statistically indistinguishable total copper content results for subsamples with a wide range of sample masses. Upon pooling all subsample results, an overall total copper content for the composite brake wear debris sample was determined to be 10.8% (g/g), with a 95% confidence limit of +/- 0.5% (g/g). Copper leaching increased with decreasing solid-to-liquid ratios in TCLP tests, but was unaffected by the solid-to-liquid ratio in the WET. For a 1:10(4) (g/g) solid-to-liquid ratio, 85% and 99% of the total mass of copper present in the composite brake wear debris sample was leached into solution during the TCLP and WET, respectively. Rate studies also demonstrated that the WET resulted in a faster rate and higher extent of copper leaching relative to the TCLP. Compared to reference copper-containing materials, the composite brake wear debris sample exhibited relatively higher TCLP and WET copper leaching characteristics. The higher copper leaching exhibited by the brake wear debris sample may have resulted from its higher specific surface area and/or from changes in the chemical form of copper that occurred during the braking process.

  6. Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues

    NASA Astrophysics Data System (ADS)

    Varrica, D.; Bardelli, F.; Dongarrà, G.; Tamburo, E.

    2013-01-01

    Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy - energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed by an admixture of Sb(III) and Sb(V) in different relative abundances. Brake linings turned out to be composed by Sb(III) oxide (Sb2O3) and stibnite (Sb2S3). Stibnite was also detected in some of the particulate matter samples. The obtained data suggest that Sb2S3 during the brake abrasion process is easily decomposed forming more stable compounds such as antimony mixed oxidic forms. Sb redox speciation, in particular and well studied circumstances, may enhance the potential and selectivity of this element as a tracer of motor vehicle emissions in apportioning studies.

  7. On potentiality of brake rigging unification for freight cars with separate braking

    NASA Astrophysics Data System (ADS)

    Sinitsyn, V. V.; Kobishchanov, V. V.

    2017-02-01

    A possibility of unified rigging use with a brake cylinder (BC) in bogie areas or on a bogie in a freight car is defined. Two ranges of transmission ratios were obtained for freight cars with pressure control in cylinders with the aid of the automated mode. To change transmission ratios, two openings are supposed to be used in rigging.

  8. 30 CFR 57.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  9. Perceptual learning and the visual control of braking.

    PubMed

    Fajen, Brett R

    2008-08-01

    Performance on a visually guided action may improve with practice because observers become perceptually attuned to more reliable optical information. Fajen and Devaney (2006) investigated perceptual attunement, using an emergency braking task in which subjects waited until the last possible moment before slamming on the brakes. The subjects in that study learned to use more reliable optical variables with practice, allowing them to perform the task more successfully across changes in the size of the approached object and the speed of approach. In Experiment 1 of the present study, subjects completed blocks of normal, regulated braking before and after practice on emergency braking. Size and speed effects that were present at early stages diminished or were eliminated after practice, suggesting that perceptual attunement resulting from practice on emergency braking transfers to normal, regulated braking. In Experiment 2, practice on regulated braking alone also resulted in perceptual attunement. The findings suggest that braking is not always guided on the basis of an optical invariant and that perceptual attunement plays an important role in learning to perform a visually guided action.

  10. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  11. Method and apparatus for braking a derrick winch

    SciTech Connect

    Falcon, J.F.

    1989-09-12

    This patent describes an apparatus for braking a derrick winch with a winch brake. It comprises: a control lever remotely located from the winch; a servo-control circuit connecting the lever and brake for actuating the brake in response to movement of the lever, and including: a torque motor having a shaft mechanically coupled to the control lever; a brake activating device for actuating the winch brake; a first position transducer for sensing the position of the control lever; a second position transducer for sensing the position of the winch brake; a first force transducer for measuring the force applied to the winch brake; a first comparator; a second comparator. The first comparator being connected to receive signals from the first and second position transducers and to deliver an error signal to the torque motor and to the second comparator. The second comparator being connected to receive signals from the first comparator and from the first force transducer and to deliver an error signal to the actuating device.

  12. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... requirements of this section. The petition shall be filed as provided in § 238.21. (b) DMU and MU locomotives. The brake equipment and brake cylinders of each DMU or MU locomotive shall be cleaned, repaired, and...) Every 736 days if the DMU or MU locomotive is part of a fleet that is not 100 percent equipped with...

  13. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404 Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine shall be equipped with automatic brakes, where space permits. Where space does not permit...

  14. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404 Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine shall be equipped with automatic brakes, where space permits. Where space does not permit...

  15. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  16. 30 CFR 57.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  17. 30 CFR 57.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  18. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  19. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  20. 30 CFR 57.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  1. 30 CFR 57.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  2. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  3. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... road (free of ice and snow). Hydraulic-braked vehicles which were not subject to the parking brake... any condition of loading in which it is found on a public road (free of ice and snow). An agricultural... condition of loading in which it is found on a public road (free of ice and snow). (2) The parking...

  4. Experimental investigation of the dynamics of a brake shoe

    NASA Astrophysics Data System (ADS)

    Ivanova, T. B.; Erdakova, N. N.; Karavaev, Yu. L.

    2016-12-01

    The experimental stand is described and the results of investigation of the motion of a brake shoe are presented. In the noncritical region, the friction coefficient is determined experimentally. It is shown that its value corresponds to the condition of uniqueness of the solution for construction of this brake shoe. The dynamics observed in the paradoxical-motion region is described.

  5. Modified hydraulic braking system limits angular deceleration to safe values

    NASA Technical Reports Server (NTRS)

    Briggs, R. S.; Council, M.; Green, P. M.

    1966-01-01

    Conventional spring actuated, hydraulically released, fail-safe disk braking system is modified to control the angular deceleration of a massive antenna. The hydraulic system provides an immediate preset pressure to the spring-loaded brake shoes and holds it at this value to decelerate the antenna at the desired rate.

  6. Compressed gas system operates semitrailer brakes during winching operation

    NASA Technical Reports Server (NTRS)

    Tupper, W. E.

    1964-01-01

    To move van-type semi-trailers into and out of confined spaces, an auxiliary braking system is mounted on a standard dolly converter. Compressed nitrogen is used to actuate the brakes which are used in conjunction with a power winch.

  7. Optimal impulsive manoeuvres and aerodynamic braking

    NASA Technical Reports Server (NTRS)

    Jezewski, D. J.

    1985-01-01

    A method developed for obtaining solutions to the aerodynamic braking problem, using impulses in the exoatmospheric phases is discussed. The solution combines primer vector theory and the results of a suboptimal atmospheric guidance program. For a specified initial and final orbit, the solution determines: (1) the minimum impulsive cost using a maximum of four impulses, (2) the optimal atmospheric entry and exit-state vectors subject to equality and inequality constraints, and (3) the optimal coast times. Numerical solutions which illustrate the characteristics of the solution are presented.

  8. Magnetorheological Fluids-Earth Applications Video

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Principal investigator Alice Gast describes magnetorheological (MR) fluids and how they differ from other fluids, such as blood or milk. Gast is the principal investigator for Investigating the structure of Paramagnetic Aggregates from Colloidal Emulsions (InSPACE), which was conducted by the Expedition 6 crew onboard the International Space Station (ISS). The goal of inSPACE is to determine the true three-dimensional (3-D) low energy (equilibrium) structure of the MR fluids in a periodically interrupted magnetic field. Applications for MR fluids could include electrical clutches, brakes, robotic devices, seat suspension systems, and shock absorbers.

  9. Eigenvalue optimization against brake squeal: Symmetry, mathematical background and experiments

    NASA Astrophysics Data System (ADS)

    Spelsberg-Korspeter, Gottfried

    2012-09-01

    Brake squeal is still a challenge for design engineers and scientists. Due to cost reasons for the avoidance of brake noise only passive measures are meaningful for a broad industrial range. Many countermeasures against squeal are based on the introduction of damping, for example by using shims. In the literature on the modeling of brake squeal, the structural properties of the brake disc are most often not considered. It has however been shown analytically and experimentally that the stiffness properties of the disc are important and that splitting of double modes of the disc has a stabilizing effect. This knowledge can be used for structural optimization of brake rotors. The goal of this paper is to exploit the potential and to discuss some mathematical difficulties. Furthermore, experimental evidence for the relation of rotor asymmetry and squeal is given.

  10. Thermal Analysis and Cooling Optimization of the Magnetorheological Brake

    NASA Astrophysics Data System (ADS)

    Song, W. L.; Wang, W. Y.; Jin, X.

    2016-05-01

    In order to study the heat transfer of the magnetorheological brake, the brake was simplified to a two dimensional axisymmetric finite element model. The steady state solutions of temperature were calculated and the cloud figures of temperature of disk were plotted. The results of simulation show that the maximum temperature is 131.7°C. Based on the results of the analysis and the structure characteristics of the brake, a cooling device was design for reducing the temperature of MR brake. And then the configuration of the cooling device was optimized for lower maximum working temperature and less weight by the response surface optimization method based on finite element. Finally, the optimal geometric parameters of the magneto-rheological brake are obtained.

  11. Development of Hydraulic Friction Brake for Railway Rolling Stock

    NASA Astrophysics Data System (ADS)

    Chenvisuwat, Thum; Park, Sung-Hwan; Kitagawa, Ato

    A novel hydraulic brake pressure control (BPC) valve for the railway rolling stock was proposed in the part I of this study. As a second report, this paper is concerned with the dynamic analysis and the performance evaluation of the hydraulic brake system using the BPC valve. In order to analyze the behavior of the BPC valve, a simplified transfer function and a nonlinear model of the valve are derived respectively. By use of simple linear model, it is achieved to determine the initial values of essential parameter simply. In addition, it is also achieved to investigate overall dynamic performance of brake system and to evaluate the effect of design parameters through the numerical analysis using detailed nonlinear model. The validity of mathematical models is confirmed by experiments. Finally, the performance of the hydraulic brake system using newly manufactured BPC valve is confirmed with an actual braking device of the E2 series Shinkansen railway.

  12. Design of haptic master featuring small-sized MR brakes

    NASA Astrophysics Data System (ADS)

    Gang, Han Gyeol; Choi, Seung-Bok; Sohn, Jung Woo

    2016-04-01

    In this work, a new type of haptic master featuring small-sized MR brake is proposed and its performances are evaluated. The proposed haptic master consists of base frame, stick grip and small-sized four MR brakes for 3-DOF rotational motion and 1-DOF gripper motion. To obtain large braking torque under limited small size of MR brake, dual tapered shape inner magnetic core is proposed and its performance is evaluated via both numerical estimation and experimental test. After design and implementation of control algorithm, it has been demonstrated through experiment that the proposed actuator has good performances on tracking control of desired torques. Then, a new haptic master device is designed and constructed by adopting the proposed MR brakes and light weight frame structures. It is verified that the proposed haptic master device is effective for the real application in the field.

  13. Energy-based control of a haptic device using brakes.

    PubMed

    Cho, Changhyun; Song, Jae-Bok; Kim, Munsang

    2007-04-01

    This paper proposes an energy-based control method of a haptic device with electric brakes. Unsmooth motion is frequently observed in a haptic system using brakes during a wall-following task. Since it is generally known that a haptic system using brakes is passive due to brake's characteristics, its energy behavior has seldom been investigated. However, force distribution at the end effector reveals that the unsmooth motion of a haptic system using brakes represents active behavior of the system in the specific direction. A force control scheme is proposed that computes the gain for smooth motion by considering the energy behavior of a system. Experiments show that smooth wall following is possible with a proposed force control scheme.

  14. Engineering report. Part 3: NASA lightweight wheel and brake sub-system. Lightweight brake development. [for application to space shuttle

    NASA Technical Reports Server (NTRS)

    Bok, L. D.

    1973-01-01

    The development of light weight wheel and brake systems designed to meet the space shuttle type requirements was investigated. The study includes the use of carbon graphite composite and beryllium as heat sink materials and the compatibility of these heat sink materials with the other structural components of the wheel and brake.

  15. Fluid imbalance

    MedlinePlus

    ... up in the body. This is called fluid overload (volume overload). This can lead to edema (excess fluid in ... Water imbalance; Fluid imbalance - dehydration; Fluid buildup; Fluid overload; Volume overload; Loss of fluids; Edema - fluid imbalance; ...

  16. Magnetic braking in weakly ionized circumstellar disks

    NASA Technical Reports Server (NTRS)

    Koenigl, A.

    1986-01-01

    Recent observations of disk-like mass distributions around newly formed stars have provided evidence for rapid rotation on scales similar to less than 0.1pc with specific angular momenta much higher than typical stellar values. A likely mechanism for the extraction of angular momentum from these regions is magnetic braking by means of Alfven waves that propagate into the lower-density ambient medium. However, because of the relatively high particle densities and the correspondingly low implied ionization fractions in these apparent disks, their constituent ions and neutrals need not be well coupled to each other and could develop large relative drift velocities. For this reason, previous treatments of magnetic braking that assumed perfect coupling between ions and neutrals have to be modified in this case. In particular, one has to take into account both the azimuthal drift that develops because only the ions are directly coupled to the magnetic field and the radial drift (or ambipolar diffusion) which leads to a redistribution (and leakage) of the magnetic flux. The results of a preliminary analysis of these effects are described.

  17. Fueling active galactic nuclei by magnetic braking

    NASA Technical Reports Server (NTRS)

    Krolik, Julian H.; Meiksin, Avery

    1990-01-01

    Recent detections of massive concentrations of molecular gas near the centers of galaxies hosting active nuclei suggest that these concentrations may be the source of accretion fuel for the nucleus. However, for that to be true, an angular momentum barrier must be overcome before the material in such a cloud can reach the nucleus. It is suggested that magnetic braking of the cloud may remove sufficient angular momentum to permit its material to draw considerably closer to the central object. The mechanism is particularly effective in the limit that the gas becomes self-gravitating because removal of a fraction of the initial angular momentum can lead to dynamical instability and collapse. Any small misalignment between the initial rotation axis of the cloud and the rotation axis of the galaxy can be substantially amplified as a result of the braking. It is argued that mass accretion onto the central object may occur in episodes, in some cases with a constant mass accretion rate during each episode.

  18. Variations in gear fatigue life for different wind turbine braking strategies

    SciTech Connect

    McNiff, B.P. ); Musial, W.D. ); Errichello, R. )

    1991-06-01

    A large number of gearbox failures have occurred in the wind industry in a relatively short period, many because service loads were underestimated. High-torque transients that occur during starting and stopping are difficult to predict and may be overlooked in specifying gearbox design. Although these events comprise a small portion of total load cycles, they can be the most damaging. The severity of these loads varies dramatically with the specific configuration of the wind turbine. The large number of failures in Danish-designed Micon 65 wind turbines prompted this investigation. The high-speed and low-speed shaft torques were measured on a two-stage helical gearbox of a single Micon 65 turbine. Transient events and normal running loads were combined statistically to obtain a typical annual load spectrum. The pitting and bending fatigue lives of the gear teeth were calculated by using Miner's rule for four different high-speed shaft brake configurations. Each breaking scenario was run for both a high- and a low-turbulence normal operating load spectrum. The analysis showed increases in gear life by up to a factor of 25 when the standard high-speed shaft brake is replaced with a dynamic brake or modified with a damper. 9 refs., 9 figs., 3 tabs.

  19. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rider in order to supply and regulate the energy required for braking the motorcycle. Driver mass means... rolling tire. Power-assisted braking system means a brake system in which the energy necessary to produce the braking force is supplied by the physical effort of the rider assisted by one or more...

  20. 49 CFR 232.211 - Class III brake tests-trainline continuity inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class III brake tests-trainline continuity... § 232.211 Class III brake tests-trainline continuity inspection. (a) A Class III brake test shall be... configuration of the train has changed in certain ways. In particular, a Class III brake test shall be...

  1. Airborne asbestos exposure during light aircraft brake replacement.

    PubMed

    Blake, Charles L; Johnson, Giffe T; Harbison, Raymond D

    2009-08-01

    Asbestos containing materials are a component of many vehicle brake systems, including those found in some light aircraft. To characterize the asbestos exposure that results from the installation and maintenance of these components, an aircraft fitted with asbestos containing brake pads had brake changes performed while both area and personal air samples were taken. The brake changing process took place in a closed, unventilated aircraft hanger and all operations were performed according to the manufacturer's recommended procedure. Personal air samples did not detect any measurable amount of asbestos fibers during the brake changing or subsequent cleanup procedures. Analysis of personal samples (n=9) using phase contrast microscopy indicated airborne fiber concentrations at or below 0.003f/ml as 8-h time weighted averages (TWAs) and less than 0.069f/ml averaged over 28-30min sampling periods. Airborne chrysotile fibers were detected by two area air samples with fiber concentrations remaining at or below 0.0013f/ml over an 8-h TWA. These results indicate that normal brake changing work practices on aircraft with asbestos containing brake pads does not produce a harmful level of asbestos exposure for aircraft mechanics.

  2. Development of Hydraulic Friction Brake for Railway Rolling Stock

    NASA Astrophysics Data System (ADS)

    Chenvisuwat, Thum; Park, Sung-Hwan; Kitagawa, Ato

    In this study, a novel hydraulic brake system is proposed in order to increase the reliability of railway brake systems. The reason hydraulic brake systems have not been taken up as a practical railway brake system until now is that the brake pressure control valve inherently has internal leakage and this causes insufficient fail-safe function. Accordingly, We focus on the development of a hydraulic brake pressure control valve (BPC valve) in this study. By virtue of adopting poppet elements in the valve, the braking force is maintained without internal leakage even when the electric power supply fails. The developed BPC valve includes a built-in pressure feedback mechanism and it enables the pressure control function to be maintained when the pressure transducer is broken. The operating principle and wear compensation methods for poppet elements are also examined in this study. The experimental results verify the linearity of static behavior, the stability, and the performance of the valve in maintaining output pressure.

  3. Reaction times to neon, LED, and fast incandescent brake lamps.

    PubMed

    Sivak, M; Flannagan, M J; Sato, T; Traube, E C; Aoki, M

    1994-06-01

    Standard incandescent brake lamps have a relatively slow rise time. It takes approximately a quarter of a second for them to reach 90% of asymptotic light output, causing potential delays in responses by following drivers. The present study evaluated reaction times to brake signals from standard incandescent brake lamps and from three alternative brake lamps with substantially faster rise times: neon, LED, and fast incandescent. The study, performed in a laboratory, simulated a daytime driving condition. The subject's task was to respond as quickly as possible to the onset of either of two brake lamps in the visual periphery, while engaged in a central tracking task. Brake signals were presented at two levels of luminous intensity. The results showed that reaction times to the alternative brake lamps were faster than to the standard incandescent lamp, with the advantage averaging 166 ms for the LED and neon lamps, and 135 ms for the fast incandescent lamp. A reduction of the signals' luminous intensity from 42 cd to 5 cd increased the reaction time by 84 ms.

  4. EEG potentials predict upcoming emergency brakings during simulated driving

    NASA Astrophysics Data System (ADS)

    Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  5. EEG potentials predict upcoming emergency brakings during simulated driving.

    PubMed

    Haufe, Stefan; Treder, Matthias S; Gugler, Manfred F; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h(-1) driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  6. Behavior of aircraft antiskid braking systems on dry and wet runway surfaces: Hydromechanically controlled system

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.; Stubbs, S. M.; Smith, E. G.

    1981-01-01

    The investigation utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC-9 series 10 airplane. The landing-gear strut was replaced by a dynamometer. During maximum braking, average braking behavior indexes based upon brake pressure, brake torque, and drag-force friction coefficient developed by the antiskid system were generally higher on dry surfaces than on wet surfaces. The three braking behavior indexes gave similar results but should not be used interchangeably as a measure of the braking of this antiskid sytem. During the transition from a dry to a flooded surface under heavy braking, the wheel entered into a deep skid but the antiskid system reacted quickly by reducing brake pressure and performed normally during the remainder of the run on the flooded surface. The brake-pressure recovery following transition from a flooded to a dry surface was shown to be a function of the antiskid modulating orifice.

  7. Gravitational waves from pulsars with measured braking index

    NASA Astrophysics Data System (ADS)

    de Araujo, José C. N.; Coelho, Jaziel G.; Costa, Cesar A.

    2016-09-01

    We study the putative emission of gravitational waves (GWs) in particular for pulsars with measured braking index. We show that the appropriate combination of both GW emission and magnetic dipole brakes can naturally explain the measured braking index, when the surface magnetic field and the angle between the magnetic dipole and rotation axes are time dependent. Then we discuss the detectability of these very pulsars by aLIGO and the Einstein Telescope. We call attention to the realistic possibility that aLIGO can detect the GWs generated by at least some of these pulsars, such as Vela, for example.

  8. Brake lock mechanism for the two axis pointing system

    NASA Technical Reports Server (NTRS)

    Posey, Alan; Clark, Mike; Mignosa, Larry

    1991-01-01

    Six months prior to shipment of the Broadband X-ray Telescope to the Kennedy Space Center for flight aboard the Space Shuttle Columbia, a major system failure occurred. During modal survey testing of the telescope's gimbal pointing system, the roll axis brake unexpectedly released. Low level vibration and static preloads present during the modal survey were within the expected flight environment. Brake release during shuttle liftoff or ascent was an unacceptable risk to mission success; thus, a Brake Lock Mechanism (BLM) was developed.

  9. Effect of Electromagnetic Brake on Decreasing Unbalanced Flow in Mold

    NASA Astrophysics Data System (ADS)

    Miki, Yuji; Furumai, Kohei

    2015-06-01

    In order to clarify the mechanism of suppression of unbalanced flow in the mold under high throughput conditions in continuous casting, the effect of using an electromagnetic brake on decreasing molten steel momentum and suppressing unbalanced flow in the mold was investigated. (1) The measured value of the effect of the electromagnetic brake on decreasing molten steel momentum was consistent with the calculated value. Molten steel momentum could be reduced by more than 50% when the Stuart number was more than 3. 5. (2) Increased mold level fluctuations caused by unbalanced flow in the mold are suppressed by applying the optimum magnetic flux density with an electromagnetic brake, even under high throughput conditions.

  10. Tribomaterial factors in space mechanism brake performance

    NASA Technical Reports Server (NTRS)

    Hawthorne, H. M.

    1990-01-01

    The asbestos/phenolic pads of Shuttle Remote Manipulator System (SRMS) brakes are unsuitable for use in long life space mechanisms because their friction decreases on extended sliding in high vacuum. Dehydration of the material and accumulation of wear debris in the conforming interface of this tribosystem induces the permanent friction changes. Other polymer and some ceramic based materials exhibit similar frictional torque behavior due to the development of minimal contact patches by the interfacial debris. In contrast, high friction occurs when other ceramics form many small contacts throughout fine debris beds. Generating this latter interfacial structure during run-in ensures that the in-vacuo friction remains stable thereafter. Such materials with low wear rates are potential candidates for friction elements in SSRMS and similar mechanisms.

  11. Braking formula for electrons of relativistic speed

    NASA Astrophysics Data System (ADS)

    Bethe, H.; Bartschat, Klaus

    2014-12-01

    The current translation is by Klaus Bartschat, Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA. An attempt has been made to preserve Bethe's writing style as much as possible, including his use of "Volt" instead of "electron volt". Even though the term "stopping power" is quite common in present scientific English, we generally use "braking [capability]" rather than "stopping [power]", in order to emphasize the act [and ability] of slowing down the particle rather than the ultimate result of bringing it to a complete halt. Also, a few typographical errors were kept in the English translation to ensure the translation replicates the original paper. Please, see Section 3 of the annotation to Bethe's article [Fontes, C.J., Bostock, C.J. and Bartschat, K. 2014. Eur. Phys. J. H, 39: 517-536] for a list. The references were converted to EPJH style, and the footnotes are numbered consecutively.

  12. A Pulsar Eases Off the Brakes

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    In 2006, pulsar PSR 18460258 unexpectedly launched into a series of energetic X-ray outbursts. Now a study has determined that this event may have permanently changed the behavior of this pulsar, raising questions about our understanding of how pulsars evolve.Between CategoriesA pulsar a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation can be powered by one of three mechanisms:Rotation-powered pulsars transform rotational energy into radiation, gradually slowing down in a predictable way.Accretion-powered pulsars convert the gravitational energy of accreting matter into radiation.Magnetars are powered by the decay of their extremely strong magnetic fields.Astronomical classification often results in one pesky object that doesnt follow the rules. In this case, that object is PSR 18460258, a young pulsar categorized as rotation-powered. But in 2006, PSR 18460258 suddenly emitted a series of short, hard X-ray bursts and underwent a flux increase behavior that is usually only exhibited by magnetars. After this outburst, it returned to normal, rotation-powered-pulsar behavior.Since the discovery of this event, scientists have been attempting to learn more about this strange pulsar that seems to straddle the line between rotation-powered pulsars and magnetars.Unprecedented DropOne way to examine whats going on with PSR 18460258 is to evaluate whats known as its braking index, a measure of how quickly the pulsars rotation slows down. For a rotation-powered pulsar, the braking index should be roughly constant. The pulsar then slows down according to a fixed power law, where the slower it rotates, the slower it slows down.In a recent study, Robert Archibald (McGill University) and collaborators report on 7 years worth of timing observations of PSR 18460258 after its odd magnetar-like outburst. They then compare these observations to 6.5 years of data from before the outburst. The team finds that the braking index for this bizarre

  13. Quantification of brake creep groan in vehicle tests and its relation with stick-slip obtained in laboratory tests

    NASA Astrophysics Data System (ADS)

    Neis, P. D.; Ferreira, N. F.; Poletto, J. C.; Matozo, L. T.; Masotti, D.

    2016-05-01

    This paper describes the development of a methodology for assessing and correlating stick-slip and brake creep groan. For doing that, results of tribotests are compared to data obtained in vehicle tests. A low velocity and a linear reduction in normal force were set for the tribotests. The vehicle tests consisted of subjecting a sport utility vehicle to three different ramp slopes. Creep groan events were measured by accelerometers placed on the brake calipers. The root mean square of the acceleration signal (QRMS parameter) was shown to be able to measure the creep groan severity resulting from the vehicle tests. Differences in QRMS were observed between front-rear and left-right wheels for all tested materials. Frequency spectrum analysis of the acceleration revealed that the wheel side and material type do not cause any significant shift in the creep groan frequency. QRMS measured in the vehicle tests presented good correlation with slip power (SP) summation. For this reason, SP summation may represent the "creep groan propensity" of brake materials. Thus, the proposed tribotest method can be utilized to predict the creep groan severity of brake materials in service.

  14. Mechanical testing and modelling of carbon-carbon composites for aircraft disc brakes

    NASA Astrophysics Data System (ADS)

    Bradley, Luke R.

    densities of the tested specimens.Two types of FE model were developed using a commercially available program. The first type was designed to analyse the model composite materials for comparison with mechanical test data for the purpose of validation of the FE model. Elastic moduli predicted by this type of FE model showed good agreement with the experimentally measured elastic moduli of the model composite materials. This result suggested that the use of layered FE models, which rely upon an isostrain assumption between the layers, can be useful in predicting the elastic properties of different lay-ups of the disc brake material.The second type of FE model analysed disc brake segments, using the experimentally measured bulk mechanical properties of the disc brake material. This FE model approximated the material as a continuum with in-plane isotropy but with different properties in the through-thickness direction. In order to validate this modelling approach, the results of the FE analysis were compared with mechanical tests on disc brake segments, which were loaded by their drive tenons in a manner intended to simulate in-service loading. The FE model showed good agreement with in-plane strains measured on the disc tenon face close to the swept area of the disc, but predicted significantly higher strains than those experimentally measured on the tenon fillet curve. This discrepancy was attributed to the existence of a steep strain gradient on the fillet curve.

  15. Driver Behavioral Changes through Interactions with an Automatic Brake System for Collision Avoidance

    NASA Astrophysics Data System (ADS)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

    This paper discusses driver's behavioral changes as a result of driver's use of an automatic brake system for preventing a rear-end collision from occurring. Three types of automatic brake systems are investigated in this study. Type 1 brake system applies a strong automatic brake when a collision is very imminent. Type 2 brake system initiates brake operation softly when a rear-end crash may be anticipated. Types 1 and 2 are for avoidance of a collision. Type 3 brake system, on the other hand, applies a strong automatic brake to reduce the damage when a collision can not be avoided. An experiment was conducted with a driving simulator in order to analyze the driver's possible behavioral changes. The results showed that the time headway (THW) during car following phase was reduced by use of an automatic brake system of any type. The inverse of time to collision (TTC), which is an index of the driver's brake timing, increased by use of Type 1 brake system when the deceleration rate of the lead vehicle was relatively low. However, the brake timing did not change when the drivers used Type 2 or 3 brake system. As a whole, dangerous behavioral changes, such as overreliance on a brake system, were not observed for either type of brake system.

  16. 28. UPPER STATION, LOWER FLOOR, BULL WHEEL ROOM, SAFETY BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. UPPER STATION, LOWER FLOOR, BULL WHEEL ROOM, SAFETY BRAKE ADJUSTING MACHINERY. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  17. 22. General view inside air brake shop section of roundhouse. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. General view inside air brake shop section of roundhouse. View to west. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  18. Deterioration of the high-mounted brake light.

    PubMed

    Cameron, D L

    1995-10-01

    An unusually high failure rate in the high-mounted, center brake light was observed in a survey of normal local traffic. Such failure increases the potential for delay or error in perception of the rear lights by following drivers.

  19. Metals associated with stormwater-relevant brake and tire samples

    PubMed Central

    McKenzie, Erica R.; Money, Jon E.; Green, Peter G.; Young, Thomas M.

    2009-01-01

    Properly apportioning the loads of metals in highway stormwater runoff to the appropriate sources requires accurate data on source composition, especially regarding constituents that help to distinguish among sources. Representative tire and brake samples were collected from privately owned vehicles and aqueous extracts were analyzed for twenty-eight elements. Correlation principal components analysis (PCA) revealed that tires were most influenced by Zn, Pb, and Cu, while brakes were best characterized by Na and Fe followed by Ba, Cu, Mg, Mn, and K; the latter three may be due to roadside soil contributions. Notably elevated Cd contributions were found in several brake samples. A targeted Cd-plated brake rotor was sampled, producing results consistent with the elevated levels found in the larger sample population. This enriched source of Cd is of particular concern due to high toxicity of Cd in aquatic ecosystems. PMID:19709720

  20. 49 CFR 393.44 - Front brake lines, protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... breakage. The means used to apply the brakes may be located forward of the driver's seat as long as it can be operated manually by the driver when the driver is properly restrained by any seat belt...

  1. 49 CFR 393.44 - Front brake lines, protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... breakage. The means used to apply the brakes may be located forward of the driver's seat as long as it can be operated manually by the driver when the driver is properly restrained by any seat belt...

  2. View of main hoist wire rope drum and brakes, open ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of main hoist wire rope drum and brakes, open contact boards are in view at the far right wall - Puget Sound Naval Shipyard, Portal Gantry Crane No. 42, Pier 5, Farragut Avenue, Bremerton, Kitsap County, WA

  3. 27. UPPER STATION, LOWER FLOOR, BULL WHEEL, BRAKE AIR CYLINDER. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. UPPER STATION, LOWER FLOOR, BULL WHEEL, BRAKE AIR CYLINDER. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  4. 49. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST EQUIPMENT, BAYS 50-51/6 NORTH, TO EAST - Ford Motor Company Edgewater Assembly Plant, Assembly Building, 309 River Road, Edgewater, Bergen County, NJ

  5. 35. CONDUIT LAYOUT FOR BASCULE General overview with motors, brakes, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. CONDUIT LAYOUT FOR BASCULE General overview with motors, brakes, etc. Courtesy of Norwood Noonan Company, Chicago, 1930. - Congress Street Bascule Bridge, Spanning Fort Point Channel at Congress Street, Boston, Suffolk County, MA

  6. 54. West emergency brake in the south machinery room (interior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. West emergency brake in the south machinery room (interior of both machinery rooms is identical). Facing west. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  7. 17. VIEW SOUTHEAST, REDUCTION GEARING AND MOTOR (WITH SOLENOID BRAKE) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. VIEW SOUTHEAST, REDUCTION GEARING AND MOTOR (WITH SOLENOID BRAKE) FOR END LOCKS; VERTICAL SHAFT IN CENTER FOR MANUAL OPERATION - Grand Street Bridge, Spanning Pequonnock River at Grand Street, Bridgeport, Fairfield County, CT

  8. 50. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. FIRST FLOOR, POSSIBLE SUPPORTS FOR WATER OR BRAKE TEST EQUIPMENT, BAYS 52-53/3 NORTH, TO NORTHWEST - Ford Motor Company Edgewater Assembly Plant, Assembly Building, 309 River Road, Edgewater, Bergen County, NJ

  9. 4. FLOOR 3; GENERAL VIEW LOOKING NORTH SHOWS WALLOWER, BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. FLOOR 3; GENERAL VIEW LOOKING NORTH SHOWS WALLOWER, BRAKE LEVER, CASE FOR SCREENER, TOP OF GRAIN ELEVATOR, LAYSHAFT WHICH POWERS THE SCREENER AND ELEVATOR - Hayground Windmill, Windmill Lane, East Hampton, Suffolk County, NY

  10. 6. DETAIL OF THE BRAKE SHOE ON THE EAST DRUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. DETAIL OF THE BRAKE SHOE ON THE EAST DRUM AT THE STEWARD MINE, LOOKING EAST. THE EAST DRUM WAS UNDER SHOT, THE WEST OVERSHOT - Butte Mineyards, Stewart Mine, Intersection of Main & Woolman Streets, Butte, Silver Bow County, MT

  11. COUNTERWEIGHT, CONNECTED TO HYDRAULIC BRAKE SYSTEM, IN REAR OF VAULT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    COUNTERWEIGHT, CONNECTED TO HYDRAULIC BRAKE SYSTEM, IN REAR OF VAULT MOTOR ROOM, LOOKING SOUTHWEST. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  12. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    PubMed

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%.

  13. Experimental investigations for uncertainty quantification in brake squeal analysis

    NASA Astrophysics Data System (ADS)

    Renault, A.; Massa, F.; Lallemand, B.; Tison, T.

    2016-04-01

    The aim of this paper is to improve the correlation between the experimental and the numerical prediction of unstable frequencies for automotive brake systems considering uncertainty. First, an experimental quantification of uncertainty and a discussion analysing the contributions of uncertainty to a numerical squeal simulation are proposed. Frequency and transient simulations are performed considering nominal values of model parameters, determined experimentally. The obtained results are compared with those derived from experimental tests to highlight the limitation of deterministic simulations. The effects of the different kinds of uncertainty detected in working conditions of brake system, the pad boundary condition, the brake system material properties and the pad surface topography are discussed by defining different unstable mode classes. Finally, a correlation between experimental and numerical results considering uncertainty is successfully proposed for an industrial brake system. Results from the different comparisons reveal also a major influence of the pad topography and consequently the contact distribution.

  14. 11. STOVE NUT USED IN THE MILL WHEN THE BRAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. STOVE NUT USED IN THE MILL WHEN THE BRAKE WHEEL DROVE ONE PAIR OF MILLSTONES DIRECTLY; FOUND ON THE FIRST FLOOR OF THE WINDMILL AT WATERMILL - Windmill at Water Mill, Montauk Highway & Halsey Lane, Water Mill, Suffolk County, NY

  15. 6. North wall and east end of air brake shop ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. North wall and east end of air brake shop section of roundhouse at center. East end of boiler shop section of roundhouse to the right of air brake shop. East end of blacksmith shop section of roundhouse at far right. View to southeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  16. Modeling Hydraulic Components for Automated FMEA of a Braking System

    DTIC Science & Technology

    2014-12-23

    has to be based on a library of generic, context-independent component models. The systems that offer support to the automated generation of fault ...Modeling Hydraulic Components for Automated FMEA of a Braking System Peter Struss, Alessandro Fraracci Tech. Univ. of Munich, 85748 Garching...the hydraulic part of a vehicle braking system . We describe the FMEA task and the application problem and outline the foundations for automating the

  17. Perforated Brake Efficiency Measurements Using a 20-mm Cannon

    DTIC Science & Technology

    1993-03-01

    and exterior surfaces. Pb is the time- dependent breech pressure of the propellant gas, P0 is atmospheric pressure , and A is the bore area. The second...term is the sum of the integrals of the pressure forces generated by the N individual vents. P, is the time- and position- dependent pressure acting...brake ........................................ 37 Bla. Pressure histories for round 19534, 120-mm standard brake at 30 calibers. Data used in report

  18. Research study on antiskid braking systems for the space shuttle

    NASA Technical Reports Server (NTRS)

    Auselmi, J. A.; Weinberg, L. W.; Yurczyk, R. F.; Nelson, W. G.

    1973-01-01

    A research project to investigate antiskid braking systems for the space shuttle vehicle was conducted. System from the Concorde, Boeing 747, Boeing 737, and Lockheed L-1011 were investigated. The characteristics of the Boeing 737 system which caused it to be selected are described. Other subjects which were investigated are: (1) trade studies of brake control concepts, (2) redundancy requirements trade study, (3) laboratory evaluation of antiskid systems, and (4) space shuttle hardware criteria.

  19. Investigation of aerodynamic braking devices for wind turbine applications

    SciTech Connect

    Griffin, D.A.

    1997-04-01

    This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

  20. Reversing the antilock braking system theory for suture removal.

    PubMed

    Mangus, D J

    1987-06-01

    A simple and extremely practical technique for removal of long subcuticular sutures is possible by simply interposing a rubber band between the suture and the traction source. We have likened the technique in a reverse manner to the pulsing application of brakes in the antilock braking system now commonly found in modern automobiles. We also suggest with this paper that Prolene at this time be tried as the suture of choice in pullout repairs of all types.

  1. Hard Braking Events Among Novice Teenage Drivers By Passenger Characteristics

    PubMed Central

    Simons-Morton, Bruce G.; Ouimet, Marie Claude; Wang, Jing; Klauer, Sheila G.; Lee, Suzanne E.; Dingus, Thomas A.

    2010-01-01

    Summary In a naturalistic study of teenage drivers (N = 42) hard braking events of ≤−0.45 g were assessed over the first 6 months of licensure. A total of 1,721 hard braking events were recorded. The video footage of a sample (816) of these events was examined to evaluate validity and reasons for hard braking. Of these, 788 (96.6%) were estimated valid, of which 79.1% were due to driver misjudgment, 10.8% to risky driving behavior, 5.3% to legitimate evasive maneuvers, and 4.8% to distraction. Hard braking events per 10 trips and per 100 miles were compared across passenger characteristics. Hard braking rates per 10 trips among newly licensed teenagers during the first 6 months of licensure were significantly higher when driving with teen passengers and lower with adult passengers than driving alone; rates per 100 miles were lower with adult passengers than with no passengers. Further examination of the results indicates that rates of hard braking with teenage passengers were significantly higher compared with no passengers: 1) for male drivers; 2) during the first month of licensure. The data suggest that that novice teenage driving performance may not be as good or safe when driving alone or with teenage passengers than with adult passengers and provide support for the hypothesis that teenage passengers increase driving risks, particularly during the first month of licensure. PMID:21243109

  2. Hard Braking Events Among Novice Teenage Drivers By Passenger Characteristics.

    PubMed

    Simons-Morton, Bruce G; Ouimet, Marie Claude; Wang, Jing; Klauer, Sheila G; Lee, Suzanne E; Dingus, Thomas A

    2009-06-22

    In a naturalistic study of teenage drivers (N = 42) hard braking events of ≤-0.45 g were assessed over the first 6 months of licensure. A total of 1,721 hard braking events were recorded. The video footage of a sample (816) of these events was examined to evaluate validity and reasons for hard braking. Of these, 788 (96.6%) were estimated valid, of which 79.1% were due to driver misjudgment, 10.8% to risky driving behavior, 5.3% to legitimate evasive maneuvers, and 4.8% to distraction. Hard braking events per 10 trips and per 100 miles were compared across passenger characteristics. Hard braking rates per 10 trips among newly licensed teenagers during the first 6 months of licensure were significantly higher when driving with teen passengers and lower with adult passengers than driving alone; rates per 100 miles were lower with adult passengers than with no passengers. Further examination of the results indicates that rates of hard braking with teenage passengers were significantly higher compared with no passengers: 1) for male drivers; 2) during the first month of licensure. The data suggest that that novice teenage driving performance may not be as good or safe when driving alone or with teenage passengers than with adult passengers and provide support for the hypothesis that teenage passengers increase driving risks, particularly during the first month of licensure.

  3. Estimation of personal exposure to asbestos of brake repair workers.

    PubMed

    Cely-García, María Fernanda; Curriero, Frank C; Sánchez-Silva, Mauricio; Breysse, Patrick N; Giraldo, Margarita; Méndez, Lorena; Torres-Duque, Carlos; Durán, Mauricio; González-García, Mauricio; Parada, Patricia; Ramos-Bonilla, Juan Pablo

    2016-12-14

    Exposure assessments are key tools to conduct epidemiological studies. Since 2010, 28 riveters from 18 brake repair shops with different characteristics and workloads were sampled for asbestos exposure in Bogotá, Colombia. Short-term personal samples collected during manipulation activities of brake products, and personal samples collected during non-manipulation activities were used to calculate 103 8-h TWA PCM-equivalent personal asbestos concentrations. The aims of this study are to identify exposure determinant variables associated with the 8-h TWA personal asbestos concentrations among brake mechanics, and propose different models to estimate potential asbestos exposure of brake mechanics in an 8-h work-shift. Longitudinal-based multivariate linear regression models were used to determine the association between personal asbestos concentrations in a work-shift with different variables related to work tasks and workload of the mechanics, and some characteristics of the shops. Monte Carlo simulations were used to estimate the 8-h TWA PCM-Eq personal asbestos concentration in work-shifts that had manipulations of brake products or cleaning activities of the manipulation area, using the results of the sampling campaigns. The simulations proposed could be applied for both current and retrospective studies to determine personal asbestos exposures of brake mechanics, without the need of sampling campaigns or historical data of air asbestos concentrations.Journal of Exposure Science and Environmental Epidemiology advance online publication, 14 December 2016; doi:10.1038/jes.2016.76.

  4. Braking and cornering studies on an air cushion landing system

    NASA Technical Reports Server (NTRS)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

  5. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  6. Possible Evolution of the Pulsar Braking Index from Larger than Three to About One

    NASA Astrophysics Data System (ADS)

    Tong, H.; Kou, F. F.

    2017-03-01

    The coupled evolution of pulsar rotation and inclination angle in the wind braking model is calculated. The oblique pulsar tends to align. The pulsar alignment affects its spin-down behavior. As a pulsar evolves from the magneto-dipole radiation dominated case to the particle wind dominated case, the braking index first increases and then decreases. In the early time, the braking index may be larger than three. During the following long time, the braking index is always smaller than three. The minimum braking index is about one. This can explain the existence of a high braking index larger than three and a low braking index simultaneously. The pulsar braking index is expected to evolve from larger than three to about one. The general trend is for the pulsar braking index to evolve from the Crab-like case to the Vela-like case.

  7. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    NASA Astrophysics Data System (ADS)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  8. Loads Acting on the Mine Conveyance Attachments and Tail Ropes during the Emergency Braking in the Event of an Overtravel

    NASA Astrophysics Data System (ADS)

    Wolny, Stanisław

    2016-09-01

    It has now become the common practice among the design engineers that in dimensioning of structural components of conveyances, particularly the load bearing elements, they mostly use methods that do not enable the predictions of their service life, instead they rely on determining the safety factor related to the static loads exclusively. In order to solve the problem, i.e. to derive and verify the key relationships needed to determine the fatigue endurance of structural elements of conveyances expressed in the function of time and taking into account the type of hoisting gear, it is required that the values of all loads acting upon the conveyance should be determined, including those experienced under the emergency conditions, for instance during the braking phase in the event of overtravel. This study relies on the results of dynamic analysis of a hoisting installation during the braking phase when the conveyance approaches the topmost or lowermost levels. For the assumed model of the system, the equations of motion are derived for the hoisting and tail rope elements and for the elastic strings. The section of the hoisting rope between the full conveyance approaching the top station and the Keope pulley is substituted by a spring with the constant elasticity coefficient, equal to that of the rope section at the instant the conveyance begins the underwind travel. Recalling the solution to the wave equation, analytical formulas are provided expressing the displacements of any cross-profiles of hoisting and tail ropes, including the conveyance attachments and tail ropes, in the function of braking forces applied to conveyances in the overtravel path and operational parameters of the hoisting gear. Besides, approximate formulas are provided yielding: loading of the hoisting rope segment between the conveyance braking in the headgear tower and the Keope pulley deceleration of the conveyance during the braking phase. The results will be utilised to derive the function

  9. Thermal measurement of brake pad lining surfaces during the braking process

    NASA Astrophysics Data System (ADS)

    Piątkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Małachowski, Jerzy; Mazurkiewicz, Łukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  10. An integrated control strategy for the composite braking system of an electric vehicle with independently driven axles

    NASA Astrophysics Data System (ADS)

    Sun, Fengchun; Liu, Wei; He, Hongwen; Guo, Hongqiang

    2016-08-01

    For an electric vehicle with independently driven axles, an integrated braking control strategy was proposed to coordinate the regenerative braking and the hydraulic braking. The integrated strategy includes three modes, namely the hybrid composite mode, the parallel composite mode and the pure hydraulic mode. For the hybrid composite mode and the parallel composite mode, the coefficients of distributing the braking force between the hydraulic braking and the two motors' regenerative braking were optimised offline, and the response surfaces related to the driving state parameters were established. Meanwhile, the six-sigma method was applied to deal with the uncertainty problems for reliability. Additionally, the pure hydraulic mode is activated to ensure the braking safety and stability when the predictive failure of the response surfaces occurs. Experimental results under given braking conditions showed that the braking requirements could be well met with high braking stability and energy regeneration rate, and the reliability of the braking strategy was guaranteed on general braking conditions.

  11. Magnetostatic simulation on a novel design of axially multi-coiled magnetorheological brakes

    NASA Astrophysics Data System (ADS)

    Ubaidillah, Permata, A. N. S.; Wibowo, A.; Budiana, E. P.; Yahya, I.; Mazlan, S. A.

    2016-03-01

    This paper describes the 3D magnetostatic simulation of a novel design axially multi-coiled magnetorheological (MRB). The proposed model is expected to produce a concentrated magnetic flux on the surface of the rotor disk brake. Thus, the braking torque enhancement is expected to be higher than that of conventional big size single-coil-equipped disk-type MRB. The axially multi-coiled MRB design features multiple electromagnetic poles from by several coils placed in the axial direction outside the MRB body. The magnetostatic analysis was developed utilizing finite element software namely ANSOFT-MAXWELL in 3D environment. The distribution of magnetic flux was investigated in a pair of the coil that represents the other pairs of electromagnetic parts. The simulation was done in 0.5 mm gap filled by magnetorheological fluids (MRFs) (MRF-132DG). The simulation was performed in various applied currents i.e. 0.25, 0.5, 0.75, 1, 1.5, and 2 Amperes. The results showed that the axially multi-coiled MRB provides a considerable magnetic flux (maximum of 337 mT/area). The active energizing areas of the MRB are proven to be more intensive than the conventional MRB. The proposed MRB exhibited a compact and robust design for achieving high torque MRB.

  12. Large Eddy Simulation of Transient Flow and Inclusions Transport in Continuous Casting Mold under Different Electromagnetic Brakes

    NASA Astrophysics Data System (ADS)

    Liu, Zhongqiu; Li, Linmin; Li, Baokuan

    2016-08-01

    A mathematical model has been developed to analyze transient fluid flow and inclusions transport in a slab continuous casting mold, considering the effects of electromagnetic brake (EMBr) arrangement and magnetic field strength. Transient flow of molten steel in the mold is calculated by using the large eddy simulation. The electromagnetic force is incorporated into the Navier-Stokes equation. The transport of inclusion inside the mold is calculated using the Lagrangian approach based on the transient flow field. The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern and inclusion transport inside the mold exhibits satisfactory agreement with the corresponding measurements. With electromagnetic brake effect, the velocities around the braking region are significantly suppressed, and the recirculating flow in the lower part drops and tends to develop a plug-like flow. The EMBr arrangement has an insignificant effect on the overall removal fraction of inclusions, especially for larger inclusions. The inclusion removal rate for the flow-control mold (FCM arrangement) reduces instead compared with no EMBr, especially for smaller inclusions.

  13. A farewell to brake reaction times? Kinematics-dependent brake response in naturalistic rear-end emergencies.

    PubMed

    Markkula, Gustav; Engström, Johan; Lodin, Johan; Bärgman, Jonas; Victor, Trent

    2016-10-01

    Driver braking behavior was analyzed using time-series recordings from naturalistic rear-end conflicts (116 crashes and 241 near-crashes), including events with and without visual distraction among drivers of cars, heavy trucks, and buses. A simple piecewise linear model could be successfully fitted, per event, to the observed driver decelerations, allowing a detailed elucidation of when drivers initiated braking and how they controlled it. Most notably, it was found that, across vehicle types, driver braking behavior was strongly dependent on the urgency of the given rear-end scenario's kinematics, quantified in terms of visual looming of the lead vehicle on the driver's retina. In contrast with previous suggestions of brake reaction times (BRTs) of 1.5s or more after onset of an unexpected hazard (e.g., brake light onset), it was found here that braking could be described as typically starting less than a second after the kinematic urgency reached certain threshold levels, with even faster reactions at higher urgencies. The rate at which drivers then increased their deceleration (towards a maximum) was also highly dependent on urgency. Probability distributions are provided that quantitatively capture these various patterns of kinematics-dependent behavioral response. Possible underlying mechanisms are suggested, including looming response thresholds and neural evidence accumulation. These accounts argue that a naturalistic braking response should not be thought of as a slow reaction to some single, researcher-defined "hazard onset", but instead as a relatively fast response to the visual looming cues that build up later on in the evolving traffic scenario.

  14. Unusual Braking Indices in Young X-ray Pulsars

    NASA Astrophysics Data System (ADS)

    Frederic Archibald, Robert; Kaspi, Victoria M.; Beardmore, Andrew P.; Gehrels, Neil; Kennea, Jamie; Gotthelf, Eric V.; Ferdman, Robert; Guillot, Sebastien; Harrison, Fiona; Keane, Evan; Pivovaroff, Michael; Stern, Daniel; Tendulkar, Shriharsh P.; Tomsick, John

    2016-04-01

    Pulsars spin down over time. By measuring braking indices of pulsars, effectively the change in the spin-down rate over time, we can probe the underlying driving engine of the spin-down. For a magnetic dipole in a vacuum, n is predicted to be 3. To date, all measured braking indices are less than 3, which can be explained, e.g. by particle winds, changes in the magnetic field. In all models of braking indices, n should be nearly constant on year time-scales. Here, I will discuss two recent observation results that challenge this model, interestingly both coming from young X-ray pulsars with no detected radio emission. The first, a long-lived decrease in the braking index of PSR J1846-0258 following a burst of magnetar-like activity, and secondly, the first stationary braking index greater than three. Understanding neutron-star spin evolution is key to constraining these objects' long-term energy output and has relevance to topics ranging from pulsar wind nebulae and supernova remnants to core-collapse supernova rates, physics, and expected outcomes.

  15. The contribution of stereo vision to the control of braking.

    PubMed

    Tijtgat, Pieter; Mazyn, Liesbeth; De Laey, Christophe; Lenoir, Matthieu

    2008-03-01

    In this study the contribution of stereo vision to the control of braking in front of a stationary target vehicle was investigated. Participants with normal (StereoN) and weak (StereoW) stereo vision drove a go-cart along a linear track towards a stationary vehicle. They could start braking from a distance of 4, 7, or 10m from the vehicle. Deceleration patterns were measured by means of a laser. A lack of stereo vision was associated with an earlier onset of braking, but the duration of the braking manoeuvre was similar. During the deceleration, the time of peak deceleration occurred earlier in drivers with weak stereo vision. Stopping distance was greater in those lacking in stereo vision. A lack of stereo vision was associated with a more prudent brake behaviour, in which the driver took into account a larger safety margin. This compensation might be caused either by an unconscious adaptation of the human perceptuo-motor system, or by a systematic underestimation of distance remaining due to the lack of stereo vision. In general, a lack of stereo vision did not seem to increase the risk of rear-end collisions.

  16. Satellite Services Workshop, Volume 1

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Key issues associated with the orbital servicing of satellites are examined including servicing spacecraft and equipment, servicing operations, economics, satellite design, docking and berthing, and fluid management.

  17. 49 CFR 571.122a - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... that is common to all subsystems) shall not impair the operation of the other subsystem(s). S5... deceleration of not more than 10 f.p.s.p.s. On independently operated brake systems, the coldest brake shall...

  18. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... single subsystem (except structural failure of a housing that is common to all subsystems) shall not... deceleration of not more than 10 f.p.s.p.s. On independently operated brake systems, the coldest brake shall...

  19. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system....

  20. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... performance of the brake system....