GB349077A - - Google Patents

Abstract

349,077. Fluid-pressure brakes. WESTINGHOUSE BRAKE & SAXBY SIGNAL CO., Ltd., 82, York Road, King's Cross, London.-(Assignees of Whitaker, U. A.; 1011, Fulton Road, Canton, Ohio, U.S.A.) Feb. 20, 1930, No. 5670. Convention date, March 12, 1929. [Class 103 (i).] In brake apparatus wherein the train-pipe is vented to a chamber in making an application of the brakes, this chamber is exhausted to an extent dependent upon the pressure retained in the brake cylinder when the brakes are only partially released by the provision of a pressure retaining valve so that the effective capacity of the chamber and thus a further application of the brakes is reduced. A triple valve of the retarded release type is shown comprising a spring stop 16 for preventing the movement of the valve from the full release position shown. In this position, air feeds from the trainpipe 2 to the auxiliary reservoir 3 through passage 8, piston chamber 7 passages 23, 25, valve chamber 12 and passage 13. The brake cylinder 4 exhausts through passage 26 valve cavity and a pressure retaining valve 6 provided with a cock 21 whereby the cylinder may as shown be directly connected to the atmosphere by the port 29 or through a spring loaded valve 17 and restricted port 20. In the release position of the valve also, the trainpipe venting chamber 5 is connected by passage 30 and valve cavity 31 to the brake cylinder passage 26 and thus to the exhaust passage 28. When the train-pipe pressure is reduced to effect a service application of the brakes, the valve port 32 is uncovered by the graduating valve and registers with the passage 26 to supply the brake cylinders from the valve chamber 12. At the same time the train-pipe is connected to the chamber 5 by the passages 8, 34, valve cavity 31 and passage 30. If the train pipe is subsequently raised to return the valve to release position both the brake cylinder and the chamber 5 are connected to the exhaust passage 28 and if the pressure retaining valve 17 is operative the chamber 5 only partially exhausts and to the same degree as the brake cylinder. If then a subsequent application of the brakes is made the effective capacity of the chamber 5 and the venting of the train-pipe effected by it is diminished.