A quick release valve for a vehicle fluid pressure braking system includes a housing having inlet, exhaust and delivery ports. A bead circumscribes the inlet port to provide a valve seating area for a flexible diaphragm within the valve housing, and the exhaust port includes a projecting portion which preloads the flexible diaphragm into engagement with the bead circumscribing the inlet port. Accordingly, pressure variations between the ports cannot force the flexible diaphragm to vibrate to create an undesirable honking noise. Furthermore, the circumferentially extending bead assures a pressure-tight seal with the flexible diaphragm, and also establishes a predetermined sealing area for the diaphragm, thereby reducing valve hysteresis by preventing sealing of the diaphragm at varying areas on the housing.
A valve has a direct flow passage extending therethrough. A flexible diaphragm (170) is positioned between a main valve seat (156) and an exhaust seat (172). Flow of pressurized air into the valve (110) through the inlet port (142) deflects the diaphragm (170) away from the main seat (156) and seals it against the exhaust seat (172). Higher pressure at the delivery port (144) than the inlet port (142) move the diaphragm (170) away from the exhaust seat (172) and against the main seat (156). A shunt passageway communicates portions of the flow passage on opposite sides of the diaphragm (170) to prevent maintenance of residual positive pressure on the delivery side of the diaphragm (170). The shunt passageway includes a groove (161) along the frustoconical main seat (156) and peripheral cutouts (171) on the diaphragm (170). In one embodiment (210) of the valve, a push member (272,276) moves against the diaphragm (270) to help unseat it from the exhaust seat (272).
A simplified and less-costly quick-release valve with controlled hysteresis for a vehicle spring-set air-release parking brake system lengthens the operating life of the valve, reduces energy consumption, extends compressor life and alleviates noise problems. The valve comprises a valve body and a plurality of internal passageways each of which is selectively connectable to at least another of the passageways. The selective connection is controlled by an integrally-formed flexural spring-brake-control release diaphragm within the valve body and disposed to either isolate or selectively connect the passageways depending on the relative pressure conditions within the passageways and respective areas of the diaphragm exposed to the pressures. The components are designed so that the normal variations or cycling of the supply or intake pressurized air does not cause cycling of the pressure in the spring-brake chambers.
A flow control device in which a plurality of flow channels converge in a two-part housing containing a free-floating and pre-biased flow control diaphragm and an injection site. The free-floating diaphragm is at the entry position of an intermediate channel which extends to an output channel of the injection site. The control diaphragm is pre-biased by a prong which extends from a base portion of the two-part housing.
A pressure piloted release valve (80) is disposed within an adaptive braking system (10) having shuttle valves (34, 44, 54, 64). The release valve (80) provides for a quick release of fluid pressure buildup within the adaptive braking system (10) so that an associated shuttle valve (34, 44, 54, 64) will return to a normal braking position and cease restricting fluid flow with an associated wheel brake (30, 40, 50, 60). The release valve (80) includes a differential area release valve (100) received with a valve body (83) having a stepped bore (90). The valve body (83) includes a frustoconical-shaped body chamber (120) with a radial passage (124) such that displacement of the release valve (100) results in a second end (105) of the release valve (100) engaging sealingly a sloped end wall (102) of the body chamber (120) to prevent fluid flow through a longitudinal through passage (101) of the release valve (100) to a receptacle chamber (85) via the radial passage (124). The valve body (83) includes a poppet check valve passage (123) that communicates with the body chamber (120). A poppet check valve (130) normally permits fluid communication through the longitudinal through passage (101) to a receptacle end opening (84), and fluid pressure received at the receptacle end opening (84) causes the check valve (130) to close. When fluid pressure received from a master cylinder (12) and communicated with a first end opening (88) of the valve body (83) is terminated, the release valve (100) shuttles open very quickly and allows the fluid pressure at the receptacle end opening (84) to be communicated quickly to the master cylinder (12).
An integrated pressure exhaust valve and pneumatic coupling is used on a truck trailer for bringing air brake pressure from a tractor to the truck trailer. A gladhand coupling moiety is used for quick connection with an identical coupling moiety on the air pressure hose from the tractor. A check valve mechanism is incorporated in the body of the trailer coupling moiety for permitting air flow to the brakes when pressure from the tractor is greater than pressure in the trailer brake lines, and for permitting air flow from the brake lines to the atmosphere when pressure from the tractor is decreased. The integrated pressure exhaust valve and pneumatic coupling moiety can be mounted on the front of the trailer where it is found that pressure exhaust valve placement is most effective.
