Abstract: A brake control apparatus includes: a master cylinder; a wheel cylinder; a hydraulic pressure source; a control valve arranged to increase or reduce the pressure of the wheel cylinder; an outside gate valve arranged to connect or disconnect between the master cylinder and the wheel cylinder; a brake operation sensing section configured to sense a driver's brake operation; and a control unit configured to control the hydraulic pressure source, the control valve, and the outside gate valve, to perform an automatic-brake pressure-increasing control to control the outside gate valve in a valve closing direction, to drive the hydraulic pressure source, and thereby to increase the pressure of the wheel cylinder in accordance with a vehicle condition, and to increase a driving quantity of the hydraulic pressure source when the brake operation is sensed during the automatic-brake pressure-increasing control.

Abstract: A brake pipe control apparatus of the type that defines primary and control passage networks has been improved. The primary passage network interconnects the brake pipe to at least one pneumatic valve in the apparatus. The control passage network interconnects a source of control pressure to at least one magnet valve used to cause operation of the pneumatic valve(s). The improvement includes first and second check valves and a passageway added between the two passage networks. The first check valve is incorporated into the control passage network between an inlet channel thereof that connects to the source and a branched channel thereof that connects to the magnet valve(s). The first check valve is situated to prevent air from flowing to the source from the branched channel when pressure in the source is low relative to pressure in the branched channel. The passageway interconnects the branched channel and the primary passage network.

Abstract: A proportioning valve assembly (10, 130) in a housing (12) is pressure responsive to control the flow of fluid to a wheel brake cylinder. The proportioning valve assembly (10, 130) includes a movable retainer (50) coupled with a differential piston (30) for movement therewith, a stationary retainer (70) mounted by the housing (12) and surrounding a second piston (80) having an enlarged diameter portion (88) that defines with an end (11, 16) of the housing (12) a chamber (90). The second piston (80) has a poppet (84) extending into an interior opening (54) of the movable retainer (50), the movable retainer (50) supporting a seal (56) disposed about the extension (82) of the second piston (80). The seal (56) is positioned for closing an opening (73) of the stationary retainer (70) through which the second piston (80) extends.

Abstract: An empty or loaded railroad brake control device includes a valve adapted to communicate a brake cylinder pressure chamber with a supplemental volume reservoir when the railroad car is not fully loaded. The valve is held in the closed position by a spring, but when a car is less than fully loaded, a load sensing device determines the relative position of the sprung and unsprung portions of the vehicle and transmits this information to the valve which opens to communicate the supplemental volume reservoir with the brake cylinder pressure chamber. The valve includes a pressure release valve, adapted to release the pressure from the supplemental volume reservoir when the brakes are released. An overpressure valve permits partial build-up of the pressure in the brake cylinder before the supplemental volume reservoir is connected.

Abstract: A service brake accelerator having a line chamber (3) connected to the main air supply line (1) and a reference pressure chamber (6) connected to the line chamber via a nozzle (7). The line chamber is separated from the reference pressure chamber by a diaphragm piston (5) which is biased by a spring (10) against a valve seat (9) projecting into the reference pressure chamber and restricting a nozzle opening (23) to the inner chamber (24) of a second valve seat (20). A second diaphragm piston (17) is biased against this second valve seat by a spring (21). The space (16) surrounding the second valve seat can be connected, partly throttled, via a nozzle (14), to the line chamber by way of a shut-off valve (12, 13) which opens laterally of the reference pressure chamber upon overbalancing pressure upon the first diaphragm piston; this space is always open to atmosphere via a further nozzle (25). The accelerator operates cyclically and has a safe, stable neutral position between its work cycles and rest position.

Abstract: This invention relates to a railway vehicle continual quick service valve device that operates in reoccurring cycles so long as fluid under pressure is being released from a train brake pipe by a brake valve device on the locomotive to, upon each cycle, locally release fluid under pressure from the train brake pipe to atmosphere via this valve device on each vehicle.