GB864378A - Improvements relating to compressed fluid braking apparatus of the graduated releasekind - Google Patents

Abstract

864,378. Fluid-pressure brakes. WESTINGHOUSE AIR BRAKE CO. July 23, 1957 [July 27, 1956], No. 23572/57. Class 103 (1). A compressed fluid braking apparatus of the graduated release kind comprises a control reservoir 3 charged from brake pipe 2 through a fast charging communication including passage 34, valve 95, choke 97, passage 98, bore 99 of valve 52, passage 100, chamber 46 in valve 45 and passage 16, and a slow - charging communication via a branch of passage 34, chamber 32 of valve 25, passage 33, past valve 68, passage 71, choke 103, passage 100, chamber 46 and passage 16, the valve 52 closing when control reservoir pressure acting in chamber 49 reaches a predetermined value, the valve 68 being associated with a quick service valve means 11 which, in response to a slight reduction in brake pipe pressure, closes the slow charging communication in addition to locally further reducing the brake pipe pressure, the valve 45 closing secondarily, the slow charging communication while the brakes are applied; an auxiliary reservoir 4, for supplying compressed fluid to at least one brake cylinder 5, is also charged through separate fast and slow communications. A valve 101 closes the auxiliary reservoir fast charging communication when pressure reaches a predetermined value and valves 68 and 45 both close the slow charging communication as for the control reservoir slow charging communication. The pressures in the control and auxiliary reservoirs 3, 4 equalizing with brake pipe pressure via the slow charging communications. A reduction ensuring valve means 12 controls the communication of a quick service volume 77 to atmosphere via passages &c. 76, 46, 94 and 93, the valve 82 closing the communication to port 93 in response to brake cylinder pressure in chamber 87 and control reservoir pressure in chamber 80 acting on diaphragms 86, 78, respectively, overcomes springs 88, 89 and the reduced 'brake pipe pressure in chamber 81. Reduction in brake pipe pressure acting in chamber 67 allows valve 68 to be moved by auxiliary reservoir pressure in chamber 66 to close passage 71 and then passage 70 from passage 33 and pipe 2, the pipe 2 being locally vented via passages &c. 34, 67, 72, 76 and volume 77. The brake pipe pressure in chamber 17 of service valve 7 allows control pressure in chamber 15 to raise valve 25 and poppet valve 37 to pressurize the brake cylinder from auxiliary reservoir 4 via passages &c. 39, 38, 37, 27 and 22, the valve 7 eventually being returned to a lap position by brake cylinder pressure in chamber 21. Brake cylinder pressure acts via passages &c. 22, 90, 91, in chamber 42 of valve 8 to shift valve 45 to close the slow-charging communication, and acts in chamber 87 of valve device 12 to move valve 82 to cut off the venting passage of volume 77. An increase in brake pipe pressure causes valve 7 to close valve 27 and release fluid from brake cylinder 5 via passages &c. 22, 27, 28, 29, 35 and choke 36. Specification 803,685 is referred to.