GB297401A - Improvements relating to fluid pressure braking apparatus - Google Patents

Abstract

297,401. Le Clair, L. J., Brackenbury, A. G., and Westing-house Brake & Saxby Signal Co., Ltd. June 20, 1927. Fluid-pressure.-A release, accelerating or other controlling valve device for fluid-pressure braking-apparat.us is provided in the body of the valve device in a conduit leading from the train pipe to the brake cylinder with a non-return valve having an aperture therein, or a byepassage around the valve in order to restrict the flow of fluid to the brake cylinder, but allow free flow from the brake cylinder. The invention is shown applied to vacuum brakes but may be applied to fluid-pressure distributing, accelerating, &c. valves. In an accelerating valve for a vacuum brake, Fig. 3, the non-return valve comprises a pivoted flap 36, having an aperture 37, in the passage 35 leading to the brake cylinder. The accelerating poppet valve 27 is normally maintained closed by a spring 38. Increase of pressure in the train pipe 29 causes it to rise and admit air from the pipe 30 as the vacuum in a chamber 33 above a diaphragm 34 controlling the valve cannot be sufficiently quickly destroyed through the restricted aperture 32 through the valve. This valve device may be arranged in the branch pipe from the train pipe to the brake cylinder. The invention is also shown applied to a release valve and the non return valve comprises a poppet valve adapted to close grooves in the wall of the passage in which it is arranged when fluid flows from the train pipe to the brake cylinder, restricted flow of fluid being allowed through an aperture in the valve or a by-passage around it.