GB191226371A - Improvements in Valve-gear applicable for use with Automatic Vacuum Brakes. - Google Patents

Abstract

26,371. Vacuum Brake Co., and Dover, H. J. Nov. 16. Fluid-pressure.-In vacuum brakes for electric trains, tramcars, &c., a deadman' valve is used in connexion with valve apparatus constructed as shown in Fig. 3 to admit air to the train-pipe when the driver becomes incapacitated. The train-pipe is formed in two portions b, d, leading respectively from the valve apparatus and ' deadman ' valve a, Fig. 1, to the exhaust pump c, and to the brake cylinder e and vacuum reservoir f. The valve apparatus comprises a diaphragm g, open above to the atmosphere and connected below by a passage h to the pilot valve of the deadman ' valve and by a restricted passage j with the train-pipe b. The stem g<1> is connected also to a second diaphragm k and to valves k<1>, l. When the pilot valve is actuated due to failure of the driver, air is admitted to the valve apparatus by the passage h and raises the diaphragms, thus closing the valve k<1> and cutting off the right-hand portion of the pipe b, which leads to the exhaust pump, from the left-hand portion which communicates with the pipe d through the driver's valve. At the same time, the pipe d is opened to atmosphere past the valve l. In a multiple-unit system, the portions b, d, of the train-pipe on each vehicle are coupled separately throughout the train, so that operation can be effected from the driver's valve of any vehicle. A spring- .loaded valve in the pipe b admits air when the vacuum reaches a certain maximum.