Abstract: An automatic emergency brake system for an automotive vehicle with an assistor having a backward push rod connected to a forward push rod coupled with a master cylinder's piston via a power piston and pushing the power piston so as to augment a force applied to a brake pedal by a driver, including a partition fixed to the backward push rod; a return spring disposed between the partition and a poppet; moving stoppers each having a moving rod, going in and out of a backward pushing rod housing, to support the back of the partition; an emergency spring disposed compressed between the moving stoppers and a housing end; a controller electrically connected to the moving stoppers to output a driving signal to the moving stoppers in accordance with a deceleration; and a deceleration/acceleration sensor electrically connected to the controller to input a reduced speed of the vehicle to the controller.

Abstract: Two methods of calibrating Fax machines are disclosed. The first method utilizes a pre-printed calibration chart and a computer connected to the Fax machine to be calibrated. The calibration chart is fed into the Fax machine which sends the resultant data to the computer. This data is analyzed by the computer to determine when the Fax machine started to scan the calibration chart. If the scan process did not occur at an optimum point, the computer sends a correction value back to the Fax machine to cause the Fax machine to begin scanning subsequent documents at an optimum point. In the second method, a calibration chart is printed by the Fax machine and then fed back into the machine. A copy of the scanned calibration chart is made to determine at what point the Fax machine began scanning the chart. If the Fax machine did not begin scanning at an optimum point, a user reads the copy and manually enters a corrective offset in to the Fax machine such that subsequent documents are scanned properly.

Abstract: A wheel safety system for a vehicle. The wheel safety system includes wheel sensors and a brake control module. The wheel sensors are mounted on the vehicle proximate each of the wheels. The sensors detect if a wheel has become disconnected. The brake control module is coupled to the brake system for the vehicle and in response to a wheel sensor detecting a disconnected wheel, the control module actuates the brake system to arrest movement of the wheel.

Abstract: A plurality of electrical fluid pressure control valves or a plurality of groups each comprised of a plurality of electrical fluid pressure control valves are operatively associated with respective power supply replays. The electrical fluid pressure control valves and a plurality of electrical switch valves are connected in parallel to a power source. A plurality of failure sensors are associated with the respective electrical fluid pressure control valves or the respective groups so as to detect whether an electrical system failure in any one of the electrical fluid pressure control valves or the groups occurs. If occurs, failure control unit is operable to control a corresponding one of the power supply relays so as to cause a corresponding one of the electrical switch valves to selectively connect a corresponding one of the wheel cylinders to a master cylinder.

Abstract: A parking brake control assembly for a motor vehicle is provided which includes a housing, a movable actuator disposed in the housing which is operable to apply or release parking brakes, and an actuator spring pivotably mounted in the housing. The actuator spring pivots in response to the movement of the movable actuator. A portion of the actuator spring is biased to a first position by a predetermined force, and if the force applied on the portion exceeds the predetermined force, the portion moves to a second position. The housing also houses a switch actuatable by movement of the movable actuator for indicating desired position of the parking brakes, and a piston in fluid communication with a source of fluid. The piston is positioned adjacent the portion of the actuator spring, and the piston is movable by the pivoting movement of the actuator spring to cause fluid to be ejected such that the ejected fluid indicates desired position of the parking brakes.

Abstract: A brake system for a motor vehicle selectively brakes single or multiple wheels. The brake system includes a hydraulic master cylinder which is actuated by a brake pedal and which is connected by an electrically controlled valve arrangement to hydraulically operated brakes on both sides of the vehicle. The brake system also includes an electric switching device for controlling the valve arrangement in order to selectively connect the master cylinder with the brakes of both sides of the vehicle or with a brake on one side of the vehicle The electrical switching device includes a manually operated, spring centered rocker switch which can be switched from a central position into two deflected positions.

Abstract: A brake device includes actuators (31) for brake pads (30), which can be pneumatically powered to which urge the brake pads (30) into engagement with a brake disc (20). The actuators (31) are mounted on a front housing portion (2) which is pivotable on a rear housing portion (4) to open the housing and allow access to the actuators (31), as for servicing. Opening the housing causes a normally closed orifice (49) in the compressed air supply line to be opened, relieving pressure on the actuators (31), and protecting them from damage.

Abstract: A motor vehicle safety device including a microswitch connected in series between the ignition system and battery power supply of a motor vehicle, and a float device disposed in the brake oil cup of the oil brake system of the motor vehicle and actuated to switch off the microswitch when the level of the brake fluid in the brake oil cup of the oil brake system of the motor vehicle drops below a predetermined level.

Abstract: A braking system which employs redundant hydraulic systems. The system has a first hydraulic system coupled to the brake of a first wheel through a first switching valve, and a second hydraulic system coupled to the brake of a second wheel through a second switching valve. Each switching valve will switch the coupled brake to the other hydraulic system, if the pressure within its system falls below a threshold value. For example, if the first hydraulic system fails, the first switching valve switches the first wheel to the second hydraulic system. If the second hydraulic system fails, the second switching valve switches the second wheel to the first hydraulic system.

Abstract: A tamper-resistant independent brake valve device for use in a brake equipment on railway locomotives including a main body casing carrying a movable handle, a rotatable cam, a pivotal cam dog and an exhaust and supply valve assembly, a spring housing attached to the main body casing by a plurality of one-way screws, a break-away adjusting screw for setting the maximum brake cylinder pressure on the railway locomotive, the pivotal cam dog including an enlarged head portion to preclude the insertion of a prying tool, and the pivotal cam dog having cam engaging roller which is rotated on a round head roller pin.

Abstract: An emergency brake system for wheeled vehicles includes a deformable brake wedge for each tire on one of the vehicle's axles. The brake wedges are constructed and arranged to transfer substantially all braking forces to the vehicle through the vehicle's tires during emergency braking. The system also includes releasable device for allowing the brake wedges to move between inoperative and operative positions and electrically-controlled device for retaining the brake wedges in those positions. While the brake wedges move from the inoperative position to the operative position, a control system temporarily applies the vehicle brakes associated with the tires that engage the brake wedges during emergency braking.

Abstract: A lock-out assembly having a latching mechanism by which means a plunger may be manually depressed and latched in a lock-out position in which a lock pin is pre-set by engagement with an actuator rod of an empty/load valve or the like, so that in response to axial extension of the actuator rod sufficient to align a locking groove in the actuator rod with the lock pin, locking engagement therebetween will occur to limit further axial extension of the actuator rod, without any further action on the part of the operator. Automatic disengagement of the lock pin from the locking groove of the actuator rod occurs in response to axial retraction of the actuator rod, by effecting disengagement of the latching mechanism to allow a return spring to reset the plunger.

Abstract: An operating brake valve for an electrically and pneumatically actuated braking system in a motor vehicle has a movable thrust piece (2) arranged within a housing (1) and a balance piston (4) actuated via a graduated spring (3), whereby a combined inlet/exhaust valve (7, 9, 10) is arranged downstream of the balanced piston. A position sensor (20) is provided which can be actuated via a push rod (17) connected to the thrust piece (2). A stop valve (29) is located in the connecting line (26) to the reservoir (12) or in the control line (15) coming from the balance chamber, whereby an electrically controlled solenoid valve (40) is provided for actuating the stop valve and, in the nonexcited state, for relieving the valve body of the stop valve (29) opposite to its closing direction.

Abstract: A parking brake system is provided which includes a dual solenoid operated valve located in series with the emergency brake control valve of a hydraulically operated brake system. The dual solenoid valve is operable to either one of two mechanical detent positions so that positioning of the valve is retained in the event of loss of power. The dual solenoid valve is controlled by the vehicle operator from the transmission console and removes fluid pressure from the brakes when actuated to a PARK position. An electronic control unit is provided for sensing the speed of the vehicle and the pressure in the hydraulic line to the brakes and provides a PARK enabling signal when the vehicle speed is below a predetermined amount. When a gear is selected at the console the dual solenoid valve is actuated to a position permitting fluid pressure to be applied to the brakes and effectively returns control of the brakes to the emergency brake control device.

Abstract: In one embodiment the invention comprises a system (50; 200) for controlling service brake and parking functions of at least one wheel of a vehicle comprising: an electric motor (64) drivingly connected to a hydraulic pump (66) for pressurizing hydraulic fluid; the output of the pump communicated to at least one service brake (58a,b), comprising a first hydraulic cylinder (62a,b), an electronics circuit for controlling the speed of the motor (64) to regulate hydraulic pressure in the first hydraulic cylinder in response to operator braking activity (56, 64, 62), the motor and pump providing the primary means of service brake activation.

Abstract: A multi-disk braking device for a vehicle, particularly a train equipped with a braking retarder, includes a first set of metallic braking disks and a second set of carbon braking disks. Under normal operation of the train, the braking retarder is used to slow the train to a predetermined relatively slow speed, and the metallic disks are then actuated to complete the stop. If the braking retarder fails, the carbon disks, not used in normal operation, are actuated to bring the train to a slow speed or to a complete stop.

Abstract: A fluid leakage preventing device incorporated in a hydraulically-operated system which includes an accumulator for storing a working fluid under pressure, an actuator operated by the fluid supplied from the accumulator, and a control valve having an open position and a closed position for fluid communication and disconnection between the accumulator and the actuator, respectively. The fluid leakage preventing device includes a fluid leakage detector for generating an output signal indicative of the leakage flow of the fluid from said accumulator through the control valve placed in the closed position. The device further includes a valve reciprocating arrangement responsive to the output signal of said fluid leakage detector, for effecting at least one reciprocating movement of a valving member of the control valve.

Abstract: The present invention features a safety device that activates the air-brake system immediately upon the detection and/or occurrence of a railroad car derailment condition. The safety device includes a bar entension disposed beneath each car of a train. The extension bar is disposed transverse to the parallel rails and is positioned a few (approximately four) inches above them. When any one of the cars is caused to derail, the extension bar contacts the rail, causing a trip valve in the air-brake line to open. The opening of the trip valve gradually releases the air pressure in the line, thus automatically and instantaneously actuating the air-brake system throughout the train. The gradual release of the air pressure in the air-brake system provides more time for the engineer of the train to bring the train under control and reduces the possibility of damage and injury caused by the derailment.

Abstract: An improved hydraulically actuated brake system for off-road heavy vehicles is disclosed that include a first accumulator, a second accumulator, a first manual and pilot actuated brake valve for controlling the flow from the first accumulator to the front brakes and to a first and a second pressure comparing devices and a second manual and pilot actuated brake valve for controlling the flow from the second accumulator to the first and second pressue comparing devices. The higher pressure from the first and second pressure comparing devices is output to the rear brakes so the front brakes are set by the pressure in the first accumulator while the rear brakes are set by the higher pressure of the first and second accumulators. A separate manually actuated brake valve controls the flow from the second accumulator to a third pressure comparing device which also is connected to receive the output of the first manual and pilot actuated brake valve.

Abstract: A brake release apparatus for a vehicle equipped with a spring-applied hydraulically-released brake system. The apparatus includes a tow hook attached to the vehicle and operably connected to a hydraulic cylinder so that a towing force on the tow hook actuates the hydraulic cylinder. The hydraulic cylinder is connected to transmit a hydraulic pressure to the vehicle brakes, releasing the brakes to permit towing. A spring returns the tow hook to its original position when the towing force is removed, thereby permitting the spring-activated brakes to be reapplied.

Abstract: The present invention entails a method and a system for chocking at least one wheel of a gas truck to assure that the gas truck is not driven away from a loading station while one or more gas hose nozzles from a storage tank are connected to a tank carried by the gas truck. The tire chock interlock system of the present invention includes a tire chock assembly that is stationed adjacent a loading platform or station and includes a chock that is movable from an extended position where the same aligns with and chocks a wheel associated with the gas truck to a retracted position away from that particular wheel leaving the gas truck free to move from the loading station. A pair of nozzle cradles are provided adjacent the loading station. When not being used to fill the tank of a gas truck, the hose nozzles from a main storage tank rest on the cradle.

Abstract: A pressurized fluid control module is provided for a tractor-trailer brake system to effect the appropriate braking function.

Abstract: A safety brake for braking a moving member includes at least one active member co-operating by friction with a passive member. The active member is kept at a distance from the passive member by an incompressible fluid which opposes the effect of a drive element (7) that is coupled to the active member and tends to urge the active member against the passive member. The incompressible fluid is enclosed in a circuit (6) which possesses a frangible portion (8) such that when the frangible portion is broken in order to activate the safety brake, it constitutes an exhaust opening to allow the incompressible fluid to escape from the circuit (6).

Abstract: The invention relates to a dual brake compensator for a motor vehicle, comprising two correcting valves, of which the inlets are intended to be connected separately to two independent brake-pressure sources and the outlets to two independent brake motors, each correcting valve being capable of controlling the values of the pressures at its inlet and at its outlet according to a predetermined relation and comprising a piston subjected to elastic return means by an inlet member. According to the invention, the dual corrector includes a mechanism for comparing the positions of the inlet members of each correcting valve.

Abstract: An all-hydraulic brake release system is disclosed for use on a vehicle having a transmission fluid pressure source, a brake fluid pressure source and a spring-applied, fluid pressure-released vehicle brake. The system has a control valve block which is hydraulically connected to the transmission fluid pressure source, the brake fluid pressure source and the brake. A first, transmission clutch pressure-responsive valve in the block controls the fluid connection between the brake fluid pressure source and the vehicle brake. A second, brake fluid pressure-responsive valve in the block controls the communication of brake fluid pressure to a pilot end of the first valve. If either brake fluid pressure or transmission clutch pressure falls below respective predetermined values, the first valve closes to cut off the supply of brake fluid pressure to the brake such that the brake is applied to stop vehicle movement.

Abstract: A hydraulic braking system for controlling the hydraulic pressure of the brake actuator and wheel cylinders includes a dynamic hydraulic pressure control system which transmits boosted hydraulic pressure in response to movement of a brake pedal. A master cylinder receives brake fluid pressure from a reservoir and transmits the fluid pressure from a pressure chamber in the master cylinder to a changeover valve. The changeover valve changes over the connection between wheel cylinders of the vehicle and the dynamic hydraulic pressure control system when the powered pressure which is transmitted from the dynamic hydraulic pressure control system is less than a predetermined pressure. A valve member of the changeover valve is movable between a first and second position so as to transmit the powered hydraulic fluid from the boost pressure chamber to the wheel cylinders of the rear wheels in a first position and block the transmission of the fluid in the second position.

Abstract: The circuit according to the invention is provided with a wheel anti-lock device of the type with independent control of the front wheels and control of the back wheel brakes by way of the pressure in the brake associated with the back wheel having the lowest resistance to skid. It comprises a safety device protecting the normal functioning of the circuit against escapes from the release valves (18, 18', 18") of the isolation-release electrovalves (11, 11', 11") and against the failure of a single pump (28) which resupplies the circuit directly from the reservoir (3) of the tandem master cylinder (2). A pressure regulator (7) avoids reactions on the brake pedal (2). The circuit may be applied to an anti-locking brake circuit having increased compactness and reliability.

Abstract: A vehicle wheel brake system having a service braking section and a wheel lock control (ABS) section is provided. Under certain conditions the wheel lock control section may not be able to generate sufficient pressure to operate the vehicle wheel brakes when the master cylinder output pressure has been isolated from the wheel brakes. When such conditions occur, the displacement piston of the ABS control section moves to open a bypass valve which connects master cylinder output pressure to the vehicle wheel brake even though the ABS system has isolated it from that wheel brake. The bypass valve is a two-stage orifice valve arrangement which provides orifice control of master cylinder pressure during initial brake actuation and provides two stage valve opening action when the master cylinder output pressure is to be delivered to the wheel brake to actuate that brake irrespective of the attempted control of the wheel brake by the ABS section of the brake system.

Abstract: A dual-circuit brake system for utility vehicles is disclosed which enables simultaneous anti-skid regulation in two brake circuits (I, II). To this end, the brake cylinders of the axle of the first brake circuit (I) that is equipped with sensors is monitored directly by pressure control valves and dependent thereon the brake cylinders of the second brake circuit (II) are monitored via relay valves. The circuits are secured from one another via a pressure control lock valve.

Abstract: A manually/electrically operated brake system for applying a brake to a wheel of a vehicle, including a master cylinder operated by a brake operating member, to generate a manually controlled braking pressure according to an operation of the brake operating member, a wheel brake cylinder for applying a brake to the wheel, a primary fluid passage for connecting the master cylinder to the wheel brake cylinder, an electrically controlled pressure generating device for generating an electrically controlled braking pressure to produce a required braking effect determined based on at least one of an operating force and an operating stroke of the brake operating member, and a switching device provided in the primary fluid passage, for applying the electrically controlled braking pressure to the wheel brake cylinder while disconnecting the master cylinder from the wheel brake cylinder when the electrically controlled pressure generating device is normally functioning, and for applying the manually controlled braking

Abstract: A brake source select system for selecting one of a plurality of sources of pressurized hydraulic fluid for use in actuating a brake system. The brake source select system (10) includes a primary, secondary and reserve source (20, 22 and 24) of pressurized hydraulic fluid connected in fluid communication respectively to a primary selector valve (32), a secondary selector valve (96) and a reserve selector valve (102). Pressurized hydraulic fluid from the primary source (20) is applied to deselect ports (94 and 100) on the secondary and reserve selector valves, causing those valves to block fluid flow from their associated sources to the brake system, so long as the primary source is operative.

Abstract: A brake control apparatus for a vehicle includes a brake apparatus of the drum brake type; an electromagnetic valve arranged in a conduit between a wheel cylinder and a master cylinder; and a detector for detecting one directional movement of the brake friction members of the brake apparatus due to a backward rotational force of a wheel and another directional movement of the brake friction members due to a forward rotational force of the wheel when the brake friction members are pressed to the frictional surface of the rotator. The brake friction members being able to move within a predetermine range in accordance with the torque of the wheel. The detector includes a slide anchor slidably fitted to a through hold in a stationary anchor, the brake friction members being engaged with the slide anchor, and an electrical switch for detecting the movement of the slide anchor. The valve being closed and opened by the detecting output of the electrical switch.

Abstract: A hydraulically-actuated brake system for off-road, heavy vehicles that includes separate accumulators for braking the front and rear brakes and brake valves that are both manual and pilot actuated for controlling the flow of hydraulic fluid from the accumulators to the brakes. Also included are valves for comparing the pressure in the front and rear accumulators so that, should one of the systems become low, the brakes are immediately set. Also included is a manual valve for overriding the brake valves in the event that a malfunction occurs in one of the brake valves.

Abstract: An improved automatic train-line air brake pressure monitoring system includes circuits that emulate an automatic brake valve and cause an automatic brake manifold release whenever a four psi increase in pressure is sensed. The system includes a pressure sensor amplifier (10) which provides a signal proportional to the sensed pressure in a brake pipe. This signal is tracked by a peak hold circuit (12) that stores the peak value of the signal. The output of the sensor amplifier is subtracted from the output of the peak hold circuit in a subtractor (14) to provide a difference signal. The difference signal is tracked by a reduction hold circuit (22) which stores the minimum value of the difference output from the subtractor. An increase in measured pressure from the stored minimum value is compared in a comparator (24) with a reference value representing the four psi level, and when the increased pressure exceeds the reference value, a system reset is generated.

Abstract: The invention is a hydraulic failure compensating switch which incorporates a differential pressure valve which responds to a hydraulic failure in one of a pair of vehicle braking circuits and altering the pressure reducing function of the braking system proportioning valve(s) in response thereto to increase braking torque at the vehicle's rear wheels.

Abstract: A hydraulic dual-circuit brake system for automobiles, comprising wheel brakes positioned at the front and rear wheels, a master brake cylinder, brake lines for transmitting brake pressure from the master brake cylinder to the wheel brakes to actuate the latter, a brake pressure regulator device incorporating a hydraulically operated switching off device interposed between the rear wheel brakes and the master brake cylinder, and a brake slip regulation device including a hydraulic unit, sensors for providing a signal output representative of wheel movement behavior, and an electronic anti-skid control and regulating device responsive to the signal output for controlling the hydraulic unit to affect the brake pressure transmitted by the hydraulic unit to the switching off endangered wheel brake.

Abstract: A differential pressure switch includes a housing which carries a switch assembly which is actuated by movement of a differential pressure responsive piston slidable within the housing. The piston shifts in response to pressure differentials between the pressure levels in the chambers defined between the ends of the piston and the corresponding ends of the housing. The piston includes a pressure responsive stop that responds to pressure levels above a predetermined pressure level to engage the housing to thereby prevent shifting of the piston and actuation of the switch assembly regardless of the pressure differential across the piston, thereby limiting operation of the pressure switch to pressure levels below the predetermined maximum pressure level.

Abstract: A fluid pressure control apparatus for a vehicle includes: an inlet port connected to a master cylinder; an outlet port connected to a wheel cylinder of a brake apparatus for a front wheel; a valve apparatus arranged in a path connecting the inlet and outlet ports; a movable plunger for closing and opening the valve apparatus, receiving fluid pressures at both sides; a first spring for urging the plunger in the direction to open the valve apparatus; an electromagnetic coil to be energized by a signal transmitted on the basis of the driver's operation for driving the vehicle backwards; the valve apparatus including a valve body which can be separated from and slated on a valve seat formed on the plunger; a second spring for urging the valve body to the first position where the valve body cannot contact with the valve seat of the plunger in spite of movement of the plunger; and the valve body being moved by energization of the electromagnetic coil to the second position where the valve body can contact with the

Abstract: A three way check valve for a vehicle fluid pressure braking system includes a housing having first, second and third inlet ports and an outlet port. A pair of shuttles are slidably mounted in the housing, and are responsive to variations in the fluid pressure at the first, second and third inlet ports to communicate the inlet port having the highest pressure level to the outlet port, and to terminate communication through the other inlet ports to prevent back-flowing from one inlet port to the other inlet port.

Abstract: An actuator including a motor having a rotary output, an actuating arm mounted for reciprocating movement, and a mechanism, interconnecting the output and the arm to convert rotary motion to reciprocating motion. The mechanism includes a rotary element. A brake is provided including a friction plate and first and second reaction plates. A solenoid and spring are operable to move the reaction plate into or out of engagement with the friction plate and cams associated with the rotary element are operable to move the reaction plate into engagement with the friction plate.

Abstract: In a hydraulic motor vehicle servo brake comprising a tandem master cylinder (11), a brake valve (17) is provided which upon actuation through the brake pedal (16) applies, in controlled manner, pressure medium supplied by a hydraulic pump (18) connected to an intake reservoir (27) to the first master piston (24) and to a brake circuit (III) directly, to provide there a controlled pressure. A wheel slip brake control system at an initial slip of one or more motor vehicle wheels, will reduce automatically the brake force on the motor vehicle wheels to a value just sufficient to turn the wheels. Two switch valves (21, 21') to which the controlled pressure is applied are normally closed and open upon a beginning slip of one or several motor vehicle wheels to apply the controlled pressure to the master cylinder (11) from where the pressure medium is passed by way of two check valves (23, 123) to the pressure chambers located behind the master pistons (24, 80).

Abstract: Hydraulic vehicle brake comprising a hydraulic accumulator (1), a brake valve adjustment device (4) supplied thereby, and a brake pressure line section (7) to the brake cylinders attached to the latter via an emergency brake valve (6). In the emergency braking position of the emergency brake valve, this connection is broken, and the brake pressure line section is directly connected to the hydraulic accumulator via a nozzle (10) which is bridged by a cylinder (13) in which a piston is sealingly displaceable. A spring (17) biases the piston in the displacement direction to the accumulator side end connection (11) of the cylinder. During emergency braking, the piston (14) first forces an amount of hydraulic medium sufficient for brake application out of the brake cylinder side chamber (16) of the cylinder (13). This is followed by a damped increase in brake pressure through additional supply of hydraulic medium from the hydraulic accumulator (1) through the nozzle (10) into the brake cylinders.

Abstract: An auxiliary air brake system is provided for a mobile vehicle which has a drive selector having reverse and other positions and which has a main air brake system which includes a plurality of compressed air tanks, main conduit including a foot brake line and a hand brake line for connecting at least one of the tanks to wheel brake chambers, and air control valves in the main conduit for controlling air pressure at the wheel brake chambers.

Abstract: An emergency brake system for a vehicle, the system including an actuator rotatable upon operation of the service brake, a follower rotatable coaxially with the actuator and normally maintained out of the path of actuator movement, and a sensor sensing malfunction of the service brake to shift the follower into the path of actuator movement, the follower being connected to the parking brake for operation of the latter by the actuator in response to a service brake malfunction.

Abstract: A backup fuel pump (16) has a thermal fuse (40) positioned in a bearing. The fuse is adapted to melt at a predetermined temperature during dry running of the pump. Melting of the fuse causes a spring urged braking member (42) to screw into a shaft journal (26) and terminate operation of the pump.

Abstract: An improved brake control apparatus for a brake system having redundant brake application fluid circuits 30, 32 and a brake retraction fluid circuit 62. A valve assembly 34, including a slidable two position valve element 60 communicates one brake application fluid circuit 30 with the retraction circuit 62, during normal brake actuation. The valve element 60 is biased towards one position by the combination of pressure in the other brake application circuit 32 and a resilient biasing arrangement 68, and biased towards the second position by pressure in the one application circuit 30. In the event of failure in the other application 32 circuit, the loss of biasing fluid pressure causes the valve element to shift to the second position, interrupting fluid communication from the one application circuit to the retraction circuit and drains fluid pressure in the retraction circuit into the failed circuit.

Abstract: A shut-off cylinder for use in a hydraulic braking system comprising a cylindrical housing, an inlet end cap and an outlet end cap received and secured in the open ends of the housing, the inlet end cap having an inlet port in fluid communication with the interior of the housing and connected to an inflow source of hydraulic fluid from a hydraulic reservoir of the braking system, the outlet end cap having an outlet port in fluid communication with the interior of the housing and connected at its output end to an outflow source of hydraulic fluid to the braking system, a piston slidably received in the interior of the housing between the inlet end cap and the outlet end cap, a coil spring received in the space between the piston and the outlet end cap biasing the movement of the piston under normal operating conditions against the pressure of the inflow source, a by-pass tube communicating with the inlet and outlet ports of the housing, a valve for opening and closing communication between the by-pass tube and

Abstract: Brake equipment for an underground mining machine, which in use traverses to and fro adjacent to a stationary rail extending along a longwall face and which includes a hydraulic haulage drive motor for hauling the machine along the longwall face, is activated to engage the stationary rail if other than a normal haulage condition of the drive motor is sensed, a control for the drive motor being moved into a neutral, machine non-traversing mode when the brake is applied.

Abstract: In an automatic train-line air brake pressure monitoring system, a peak detector and hold circuit determines the peak voltage of an input signal representing the air pressure in the air brake system. A signal representing the present peak voltage of the input signal from the previously detected peak voltage is subtracted from the presently detected peak voltage to provide a subtraction output signal such that signals representative of the air brake pressure can be generated. The monitoring system may provide emergency air brake condition signals, as well as a number of programmable monitoring signals representative of different pressures within the air brake pressure system.

Abstract: Downwardly depending contact members are secured to the undercarriage of railroad cars and positioned inboard from the wheels of the cars and also positioned above the level at which the wheels contact the underlying tracks. These contact members are upwardly displaceable when the train derails upon contact with a rail or ground debris to release fluid pressure in the train brake system and thereby activate the brakes of all of the cars.