GB746152A - Railway fluid pressure brake apparatus - Google Patents

Abstract

746,152. Fluid-pressure brakes. WESTING- HOUSE AIR BRAKE CO. Aug. 9, 1954 [Sept. 11, 1953], No. 23060/54. Class 103 (1). A triple valve for fluid pressure railway braking apparatus, connected to a brake pipe 2, supply reservoir 3 and brake cylinder 4 and having a service selector valve 6, graduating control device 7, brake cylinder inshot valve device 8, control reservoir cut-off valve device 9, quick service control valve device 10 and supply and control reservoir release valve device 11, is characterized mainly in that initial charging of the reservoir 3 from the brake pipe 2 occurs by way of one choke passage 184 which prevents overcharge of the reservoir to any appreciable extent during the time the brake pipe 2 may be overcharged at full main reservoir pressure, and an additional choke passage 500 combined with a check valve 501 is brought into action when an overcharge in the reservoir 3 is dissipated to the brake pipe when pressure therein is reduced to its full normal value. The size of the combined choke passages is made such that dissipation is sufficiently rapid to prevent an overcharge great enough to cause application of the brakes by an undesired operation of the quick service valve device 10, but not so great as to prevent a rapid drop in brake pipe pressure relative to supply reservoir pressure, to be brought about for initiating a brake application. During initial charging of the supply reservoir 3, the brake controlling valve device 7 will limit the pressure in passage 95 below the spring loaded recharge check valve 90 to prevent any charging of the supply reservoir via passages 60, 96, 60a, 26 and 27. Specification 702,100 is referred to.