GB122471A - Improvements in and relating to Railway Train Controlling Systems. - Google Patents

Abstract

122,471. McKenzie, Holland, & Westinghouse Power Signal Co., (Union Switch & Signal Co.). Jan. 23, 1918. Valves controlled by pilot or relay valves.- The train-carried valve apparatus shown in Fig. 2 includes a pneumaticallycontrolled brake - pipe venting-valve subject to two controls dependent respectively upon the electromagnets 22, 37 in the local circuits of the relays P, P<1>, the magnet 22 being de-energized if either relay P, P<1> is deenargized and the magnet 37 only if both are simultaneously de-energized. Both magnets control the escape of pressure fluid from the pipe 24, which is connected to the chamber 26 containing a piston 28 which has a leakage port 29; through which the pressure on its two sides is equalized; the pipe 30 is connected to the main reservoir. Under running conditions, the piston 29 occupies the position shown under the action of the spring 31. and the slide valve 27 connects the feed pipe 33 to the main reservoir and cuts off the brake pipe 32 from the exhaust port 44. When the pressure in pipe 24 is released the piston 29 is moved against the spring 31 to close the feed pipe and exhaust the brake-pipe. The magnet 37 directly controls a needle-valve 35, through which the pipe 24 may be exhausted. Another needle-valve 25 is controlled jointly by the magnet 22, and a centrifugal governor device 14. The magnet 22 moves a valve 20, 21 to charge or discharge a timing reservoir 23 and a chamber 18 which is closed by a diaphragm acted on by the air pressure and a spring 17 on one side and by the governor on the other side. The time interval between the opening of the valves 21, 25 is thus dependent upon the speed of the train. A stop-release magnet 40 and a manual switch 42 are provided for resetting the valves; the relay 40 remains energized until relay P or P<1> is energized.