Abstract: A brake cylinder maintaining system that combines a brake cylinder maintaining check valve and a quick service limiting valve into a single unit to have lower hysteresis, and thus more precise BCM regulation pressure and a smaller pressure offset. The check valve and quick service valve are coupled to provide a single system having multiple valve seats for selective communication between quick service pressure and brake cylinder pressure on one hand, and between a brake cylinder maintaining pressure and brake cylinder pressure on the other hand.

Abstract: A caliper brake device includes a brake shoe for exerting a friction force by sliding in contact with a disk, a caliper main body fixed to a vehicle and an actuator for pressing the brake shoe against the disk. The actuator includes an elastic film fixed to the caliper main body, a drive pressure chamber defined by the elastic film and supplied with a fluid, a valve introducing the fluid to the drive pressure chamber, and a piston interposed between the elastic film and the brake shoe. The fluid is supplied to the drive pressure chamber and the elastic film swells toward the brake shoe, whereby the piston brings the brake shoe into sliding contact with the disk. The valve introduces the fluid to the drive pressure chamber when the brake is applied while limiting the discharge of the fluid from the drive pressure chamber when the brake is released.

Abstract: A brake control system has a manual fluid pressure source and a power fluid pressure source. A fluid pressure actuator forms an X-pipe having a first channel and a second channel. The power fluid pressure source supplies the operating fluid to each wheel by using the first channel and the second channel. A channel system including the first channel and a channel system including the second channel can be isolated from each other by an isolation valve. The fluid pressure actuator includes a regulation unit configured to regulate a state of supplying the operating fluid such that a difference between a state occurring when the operating fluid is supplied to one of the first channel and the second channel after passing through the isolation valve, and a state occurring when the operating fluid is supplied to the other channel without passing through the isolation valve, is reduced.

Abstract: An electronic air charge controller for a tractor trailer vehicle air brake system includes a micro controller, a first pressure sensor interface coupled to the micro controller, a second pressure sensor interface coupled to the micro controller, and a vehicle control protocol interface coupled to the micro controller. The micro controller, in response to a signal received from the first pressure sensor interface indicative of an air supply recharge condition, a signal received from the second pressure sensor indicative of parking brake engagement condition, and a signal from the vehicle control protocol interface indicative of an engine start condition, supplies a maximum engine speed control signal to the vehicle control protocol interface. The time required to charge the air supply system to the required normal operating level is thereby minimized. In addition, a transmission sensor interface is preferably coupled to the micro controller.

Abstract: A compressed-air processing system, notably for motor vehicles, includes, in a housing, an electromagnetic pressure regulator and a multicircuit safety valve having at least one load circuit connected to it. Each load circuit can be locked separately by an assigned pressure control unit. Reliable and economical operation of the system is achieved by positioning a pressure limiter between at least one of the pressure control units and the pressure regulator output and by the fact that in the zero-current state, the pressure limiter acts on a supply hole for the control unit so as to limit the output pressure to a defined value.

Abstract: A portable, single-car test unit for a railway freight brake control valve for manually executing pressure manipulations to evaluate the operating conditions of the control valve. The pipe bracket portion is connected to a brake pipe, an auxiliary reservoir, an emergency reservoir, a brake cylinder retaining valve and a brake cylinder each being connected to a respective fluid passageway. The test unit accesses the fluid passageways at access ports, respectively connected to each passageway. Valves are utilized in the test unit to manipulate the pressure in the fluid passageways and pressure gauges measure fluid pressure in the passageways. An operator records each pressure measurement and calculates and stores the differences between selected pairs of the pressure measurements as well as elapsed time data for the measurements.

Abstract: A compressed air unloader for unloading compressed air used in the compressed air braking and suspension circuits of a motor vehicle is disclosed. The unloader includes a housing with an internal air chamber, an air inlet for passing compressed air into the air chamber, a compressed air outlet, and a controlled outlet valve in the compressed air outlet for venting compressed air in the air chamber to the atmosphere when the valve is opened. An electronic control unit opens and closes the outlet valve. The air chamber also has an air chamber check valve and a pressure sensor downstream of the check valve.

Abstract: A portable, microprocessor controlled single-car test unit for a railway freight brake control valve for automatically executing pressure manipulations to evaluate the operating conditions of the control valve. The pipe bracket portion is connected to a brake pipe, an auxiliary reservoir, an emergency reservoir, a brake cylinder retaining valve and a brake cylinder each being connected to a respective fluid passageway. The test unit accesses the fluid passageways at access ports, respectively connected to each passageway. Valves are utilized in the test unit to manipulate the pressure in the fluid passageways and pressure transducers measure fluid pressure in the passageways. The pressure transducers are controlled by a computer having a microprocessor connected to an input output device. The computer records and stores each pressure measurement, and calculates and stores the differences between selected pairs of the pressure measurements as well as elapsed time data for the measurements.

Abstract: A service brake inspection system engages service brake air lines downstream of a foot operated activation valve thereof to provide continuous engagement of the service brakes during inspection. The system includes a manually controlled air line which supplies air to a source port of an inversion valve. The inversion valve further includes an outlet port which is engaged to air lines supplying the vehicle service brake system via a double check valve in each of the primary and secondary service brake air lines, each being downstream of the foot operated valve. A third control port is connected to an air line disposed between a hand operated valve for exhausting the air lines to the spring parking brakes to set the parking brakes of the vehicle on. When the hand operated exhaust valve is set on, the pathway from the source to the outlet port in the inversion valve is opened to cause the service brakes to be continuously engaged for inspection.

Abstract: A limited service application of the service brakes of the trailer portion of a tractor trailer combination vehicle is applied and held while the vehicle operator gets out of the cab to make a pre-trip inspection. The service actuation is initiated by releasing the trailer parking brakes while the tractor parking brakes remain applied and then making a momentary service brake actuation by use of the vehicle dual control valve. A control valve assembly responds to the service actuation to hold a service actuation of the trailer brakes until either the tractor parking brakes are released or the trailer parking brakes are applied.

Abstract: A brake system for automotive vehicles, comprising a tandem master cylinder (1) and a vacuum brake force booster (2). A pump (34) is connected to the supply chambers (10, 11) of the tandem master cylinder (1), which pump is actuated by an electromotor (35) started by a brake slip control device to replenish, in the brake slip control, the pressure fluid volume discharged from the working chambers (4, 5) of the tandem master brake cylinder (1), by way of the supply chambers (10, 11) and the sleeves of the master cylinder pistons (6, 7). To control the pump pressure, a pressure control valve (36) is provided to the control chamber (37) of which a control pressure is applied, which is generated in a control chamber (23) by a control piston (24) coupled ahead of the tandem master brake cylinder (1). The control chamber (23), by way of a magnetic valve (39), is pressure-relieved when the brake slip control device is turned off.

Abstract: A fluid brake system has a brake pipe, a control valve device, a brake cylinder and a brake rigging, and in addition, a handbrake pipe, a protective device, a fluid pressure releaseable spring handbrake cylinder, and a manually operable handbrake device for selectively governing brakes of the brake rigging under varying conditions, as when air supply is disconnected from a train. A moveable fulcrum in the manual handbrake device permits manual release of spring applied handbrakes in combination with a resetable toggle locking connection to a handbrake rod.

Abstract: A plunger system in a brake line between a master brake cylinder and a wheel brake cylinder of a vehicle, for modulating a brake pressure in the event of a sensor-detected danger of wheel locking or wheel spinning. The plunger system has a plunger that is axially displaceable in a housing. At one end, the plunger engages a variable pressure chamber toward the master brake cylinder and at the other it engages a variable pressure chamber toward the wheel brake cylinder. It has an axial bore, through which a rod passes, between the two pressure chambers, and this bore can be closed on opposite ends if there is a danger of wheel locking or if wheel spinning occurs. The closure of the axial bore is effected by an axial motion of the plunger, which takes place if the wheels lock, on the one hand, and if they spin, on the other.

Abstract: A brake control system for a railway vehicle having separately operated independent and automatic brake controls for controlling brake pressure via a double check valve and a multi-piston relay valve, wherein an adjustable regulating valve is set to exhaust the independent brake control pressure acting on one piston of the multi-piston relay valve when the relay valve delivery pressure (brake cylinder pressure) exceeds a predetermined value, to thereby limit the maximum brake cylinder pressure attainable from the combined independent and automatic brake controls unless the automatic brake pressure exceeds that predetermined value.

Abstract: In an air pressure proportioning variable load valve for a vehicle compressed air braking system the operating mechanism for a self-lapping valve assembly includes a fluid pressure responsive piston arrangement which is operable above a given fluid pressure (PI) to adjust the position of the self-lapping valve arrangement relative to a variable area pressure responsive assembly whereby the rising output pressure corresponds initially to rising input port pressure up to the given pressure (P1) followed by progressive adjustment before proportioning by virtue of relative areas of the variable area assembly.

Abstract: This invention relates to a valve assembly for a railway braking system, including a brake cylinder pressure-maintaining valve which, during brake application, takes air from the brake pipe and feeds it into the brake cylinder until it reaches minimum brake pressure. To avoid the need for an extra valve, the brake cylinder pressure-maintaining valve is used as a quick service bulb exhaust valve during brake release and member are provided to ensure that the brake cylinder pressure maintaining valve opens immediately on brake release. Once the brakes have been applied, pressure in the brake cylinder is maintained from the quick service bulb 59. Brake cylinder exhaust pressure taken from a point 124 after the brake cylinder exhaust valve 50, but before the brake cylinder exhaust choke 70, is directed to chamber G above the inshot and brake cylinder-maintaining valve diaphragm 131. Since the pressure in port 124 upstream of the brake cylinder exhaust choke 70 attains a pressure well within 10 p.s.i.

Abstract: A railway vehicle brake apparatus including a brake control valve device having a service piston valve device operative responsive to a reduction of pressure in the train brake pipe to connect fluid pressure from the auxiliary reservoir to a brake cylinder device to provide a service brake application, and a high pressure spool valve device operative responsive to said reductions of brake pipe pressure exceeding a certain chosen rate to connect fluid pressure from the emergency reservoir to the brake cylinder device in parallel with the auxiliary reservoir pressure connected thereto from said service piston valve device to provide a higher emergency brake application pressure, there being arranged a cut-off valve device between the high pressure spool valve device and brake cylinder device which interrupts the flow of emergency reservoir pressure thereto until the auxiliary reservoir pressure supplied to the brake cylinder device is reduced to a predetermined level and a one-way check valve between the servic

Abstract: A safety valve device for use in a multiple circuit fluid pressure operable brake system for insuring supply and preservation, in the event of fluid pressure failure in one or more of the circuits, in the remaining circuits for assuring, at least, limited operation of the brake system.