GB846314A - Improvements relating to compressed fluid braking apparatus - Google Patents

Abstract

846,314. Fluid-pressure brakes. WESTING- HOUSE BRAKE & SIGNAL CO. Ltd., SIMMONS, A. W., and WASHBOURN, J. Sept. 25, 1958 [Sept. 25, 1957], No. 30088/57. Class 103 (1). In a direct release triple valve device for compressed fluid braking apparatus, particularly for railway vehicles, of the kind including an application valve 17 controlling the communication between a source of compressed fluid afforded by an auxiliary reservoir and a brake cylinder, not shown, the valve 17 being operable by a diaphragm 13 subject respectively on its opposite sides to auxiliary reservoir pressure in chamber 15 and the pressure in the normally charged brake pipe in chamber 14, the effective area of the diaphragm 13 exposed to brake pipe pressure is greater, at least in the normal undeflected position of the diaphragm corresponding to closure of the application valve, then the effective area exposed to the auxiliary reservoir pressure. This condition is inherent in the construction shown, as the effective area exposed to chamber 14 is substantially undiminished by the central spindle member whereas the effective area of the lower face of the diaphragm 13 is diminished by the cross-sectional area of the stems 26 and 27, which pass sealingly through bores in the respective valve bodies 28 and 29. The unbalance of effective area above and below the diaphragm 13 provides a biasing force which is sufficient to ensure that the auxiliary reservoir pressure must exceed the brake pipe pressure by more than a certain amount before the diaphragm will be moved upwardly, thus providing a resistance to movement by jolting or small fluctuations of the controlling pressure. Specification 846,313 is referred to.