Patent GB-184683-A (GB)
Title: Improvements relating to fluid pressure controlling valves
IPC: F16K15/14
Filed: 1921-07-28
Abstract: 184,683. Tomlinson, A. V., (Westinghouse Air Brake Co.). July 28, 1921. Fluid-pressure.-A valve for controlling fluic pressure braking apparatus and the like comprises a flexible resilient element adapted to be deformed under pressure in such a manner that different portions of the element control the flow of fluid through different ports. The casing 1 is provided with a cover 3 having an inlet port 6, and an exhaust port 4 is arranged in the base. A flexible disc 9, preferably of rubber, normally closes the port 4 and its outer edge is pressed against the under side of the cover. The valve disc may be slightly grooved along a portion of its upper edge, or may be provided with a small aperture 10 to allow a slight leakage of fluid from one side to the other. Fig. 2 shows the application to a braking apparatus. When the valve 13 is set so as to allow pressure fluid to pass from the reservoir 12 to the control valve 15, the circumference of the rubber disc is pressed downwards and the fluid passes to the ports 11 and thence to the brake cylinders 17. When fluid is to be released from the brake cylinders, the valve 13 is moved so as to place the pipe 14 into communication with the air, so that the pressure falls in the space 8. The fluid pressure in the space below the valve disc thus raises the central part of the disc and the fluid is discharged through the port 4 to the air. The leakage allowed through the opening 10 serves to maintain the pressure in the space 8 and to prevent the disc from lifting from the seating 5 due to leakage in the pipe 14. Fig. 3 shows a braking system for a motor and trailer vehicle. A brake cylinder 18 is connected by a pipe 19 to a control valve 20 which is shown in section in Fig. 4. Pressure fluid is supplied from a pipe 21 through check valves 25, 26 to a reservoir 21. A train pipe 28 is connected between the valves 25, 26 so that any return flow from the pipe 28 to the pipe 24 is prevented, and also any loss of pres- - sure from the reservoir 21 if the pipe 28 is broken. The control valve 20 includes a valve disc 9 of similar construction to that shown in Fig. 1, but attached to a spindle 33 carrying conical valve members 32, 34. The space 35 is connected by a pipe 37 to a hand operated valve 22, and the space 35 is connected by a pipe 37 to a hand operated valve 22, and the space 36 by a pipe 38 to the reservoir 21. The pipe 19 is connected to the brake cylinder 18 and the pipe 39 to a train pipe 40 extending to the trailer vehicle. The brake cylinder 18<1> for the trailer vehicle is connected in a similar manner to a control valve 20<1>, and the latter to an auxiliary reservoir 42. The valve 22 is shown in section in Fig. 6. A diaphragm 44 is pressed downwards by a spring 45 controlled by a handle 46, and operates a valve 47 which connects the pipes 37, 39. A valve 48 opening to the air may be operated in the opposite direction. To apply tho brakes, the valve 47 is opened so that fluid passes from the reservoir 21 to the chamber 36, through the opening 10, and thence through the valve 22 to the pipe 39, valve 32, and cylinder 18. Fluid also passes through the pipes 40 and 39<1> to a similar control valve 20<1> and brake cylinder 18<1>. If the valve 22 is opened further, the excess of pressure in the space 36 lifts the disc 9 and allows the fluid to pass through the valve 34 to pipe 19. A reduction in pressure in the reservoir 21 results in a flow back through the pipe 28 and a reduction is pressure above the disc of the valve 20'. The disc is thus lifted with its attached valves, allowing fluid to pass from the reservoir 42 to the brake cylinder 18<1>.