GB190925911A - Improvements in Air-brake Safety-valves. - Google Patents

Abstract

25,911. Gibson, O. April 5, [Convention date]. Fluid-pressure. -Valves are provided for preventing too sudden an application of air brakes when the pressure in the train-pipe is suddenly reduced by the breaking of the train-pipe, bursting of the hose couplings, or parting of the cars of the train. The valve comprises a casing 1 preferably connected to the train-pipe 2 and to the angle-cock 3 of the hose coupling, and provided with a partition 7, 8 formed with a valve seat 6. A cylinder 10 within the casing rests on the top of the wall 8 and is fitted with a piston 19, the rod of which is guided in a screw cover 13 provided with recesses 14, and is fitted at the underside of the cylinder with a valve 20. The train-pipe 2 is in communication with the recesses 14 by a passage 22, and the cylinder 10 communicates with the angle-cock 3 by a port 23. Thus the pressure is normally equal throughout the device, the parts being retained in the portion shown by a spring 21. If the pressure is suddenly reduced, say to the right of the Figure, the air rushes through the valve seat 6 and is withdrawn from the cylinder 10 through the port 23. The pressure above the piston 19, which has not been appreciably reduced as yet, forces the valve 20 on to the seat 6, whereupon the escape of air from the train-pipe takes place slowly through the passage 22, recesses 14, and port 23, the piston 19 having descended below this port. Each car is provided with one or two valves. Reference has been directed by the Comptroller to Specifications 12,475/91, 23,007/04, and 28,183/04.