GB972825A - Improvements relating to compressed fluid braking apparatus - Google Patents

Abstract

972,825. Fluid-pressure brakes. WESTING HOUSE BRAKE & SIGNAL CO. Ltd. June 13, 1961, No. 21280/61. Heading F2F. In an improvement in, or modification of, the direct release triple valve device claimed in Claim 1 of Specification 846,313, the single movable pressure-sensitive element in the form of a diaphragm 2 is provided with an operating spindle 17 for the application valve 8 arranged such that the end of the spindle acting on the application valve 8, as well as guide means therefor, is situated within the auxiliary reservoir pressure chamber of the valve housing and directly exposed to the auxiliary reservoir pressure over its entire cross-section. The diaphragm 2 of the valve, which is subjected to brake pipe pressure on one side 3 via connection tion 5 and to auxiliary reservoir pressure on the other side 4 via connection 6, includes an operating spindle 17 acting on the balanced application valve 8 forming the means which is directly exposed to the auxiliary reservoir pressure. The balanced application valve comprises a spring-loaded balancing valve member 19 surrounding part of the spindle 17, one end of the spindle having a guiding piston-like end 20 of substantially the same diameter as the balancing valve member 19, both the guiding piston end and the balancing valve member being reciprocal within a bore 21 extending from the auxiliary reservoir pressure chamber of the valve housing. Assuming that after a brake application the brakes have just been released, the brake pipe 5 is in the process of being charged to its fixed maximum braking pressure which acts in the chamber 3 to maintain the diaphragm 2 in its lowest position, as illustrated. The auxiliary reservoir charging valve 13 is held open and the compressed air passes to the auxiliary reservoir from the brake pipe 5 through a charging choke 14 and the valve 13. When the pressure in the brake pipe 5 is reduced and the diaphragm 2 rises so that the auxiliary reservoir charging valve 13 is then closed as also is the brake cylinder exhaust valve 9 and the quick service bulb exhaust valve 11. The quick service accelerator valve 7 opens and compressed air from the brake pipe fills a quick service bulb 15. The application valve 8 is lifted off its seat by spindle 17 and compressed air from the auxiliary reservoir flows to the brake cylinder through a regulating choke 16.