GB1035376A - Railway vehicle braking apparatus - Google Patents

Abstract

1,035,376. Brakes for railway vehicles. GRESHAM & CRAVEN Ltd. June 22, 1965 [Aug. 14, 1964], No. 33170/64. Heading F2F. A railway vehicle braking apparatus comprises first and second brake cylinders 2, 3; the first brake cylinder 2 being operated in response to pressure in a train pipe 1 and the second brake cylinder 3 being connected to the train pipe via a valve 6 actuated in response to the load on the vehicle, which inter-connects the upper and lower chambers of the second brake cylinder to render it inoperative when the vehicle is unloaded and which connects it to the train pipe for operation together with the first brake cylinder when the vehicle is loaded. As shown, in a vacuum brake the load on a vehicle spring 23 operates the stem of valve 6 through levers 18, 19 and a link 21. The valve 6, Fig. 2 (not shown), comprises three ports 9, 10, 11 connected respectively to pipes 7, 4, 5. In the unloaded condition of the vehicle a spring 26 moves the lever 19, and hence a a valve stem 16, upwards to interrupt fluid connection between the port 9 (connected via pipe 7 to the train pipe 1) and port 11 (connected via pipe 5 to the lower chamber of the second brake cylinder) and to establish fluid connection between the upper and lower chambers of the second brake cylinder. When the vehicle is loaded above a predetermined amount the lever 19 moves downwards against the action of spring 26, moving the valve stem 16 downwards to establish fluid connection between ports 9 and 11, and to interrupt fluid connection between ports 10 and 11 so that the brake cylinder is connected to the train pipe 1 for normal operation. A non-return valve 31, Fig. 3 (not shown), is provided between ports 9 and 11 to permit air to flow from the train pipe into the second brake cylinder to return it to atmospheric pressure when the vehicle is unloaded and disconnected from the train.