Patent GB-1036493-A (GB)
Title: Fluid pressure brake control valve device
Inventor: WILSON WILLIAM GEORGE
IPC: B60T15/30
Filed: 1964-05-04
Abstract: 1,036,493. Railway braking system. WESTINGHOUSE AIR BRAKE CO. May 4, 1964. No. 18392/64. Heading F2F. A brake arrangement is described wherein a detached rail vehicle having a high brake reservoir pressure may be coupled to a train having a brake pipe pressure below that of the vehicle's reservoir. The arrangement shown comprises a brake pipe 4, auxiliary and emergency reservoirs 2, 3, brake actuator 5, pistonoperated valves 16, quick action chamber 42, emergency valve 87, inshot valve 76, vent valve 94, manually operable release valve 132, piston valve 109 and valves 137 in chambers 133, 134, 135. Emergency and normal train braking.-The emergency valve 87 is normally in the position shown, while on controlled drop of brake pipe pressure at service braking the valve moves rightwards until slide valve 89 opens chambers 86 and 42 to the vent 95 by way of passages 92, 93, 94. During emergency braking the restriction of these passages prevent a sufficiently rapid fall in the pressure in 86 and the valve moves hard right, the main slide valve 88 allowing pressure in chambers 86 and 42 to reach chamber 98, open vent valve 100 and connect brake pipe chamber 36 to atmosphere by passages 103, 37 to reduce the brake pipe pressure through the train. Pressure in chambers 86, 42 is slowly vented through choke port 104 in piston 99 until valve 100 closes after a time lapse. The valves 88 and 23 respectively allow the pressure in reservoirs 2 and 3 and in the brake cylinder 5 to equalize. Connection of reservoir 2 with the cylinder 5 is by way of passages 27, 26, 25, 21, 68-75 and 77. Shunter control and re-connection,-Manual operation of valve handle 129 releases fluid from cylinder 5 without losing reservoir pressure, by connecting chamber 29 of the manual valve, which is connected to reservoir 2, to the lower chamber 112 to move up piston 109 to connect chamber 112 via passages 124, 116, 70, 60 to chamber 21 which is at the equalized pressure of reservoir 2. The handle is released and cylinder 5 is vented to atmosphere via passages 78, 77, 75, 74, 107, 72, and chamber 121. The equalized pressure may, for a car detached from a passenger train, be 85 to 95 p.s.i. With the connection of the car to a freight train operating at say 70 p.s.i. such pressure enters chambers 36 and 20 and, by passages 37, 145, 134, 143 to bore 138, to raise piston valve 140. This connects reservoir 2 to the brake pipe by passages 69, 70, 116, 124, 141, 144, 134, 137, 145, and 37, the pressures equalizing at about 65 p.s.i. At this lower pressure, which acts in chamber 58, the accelerated release valve 52 is actuated since the continuation of brake pipe pressure increase acts in chamber 57, which is connected to pipe 4 by passages 59, 40, 39, 36, 37. Diaphragm piston 56 moves left to open valve 61 and connect pressurized fluid from chamber 51, which is connected to the emergency reservoir 3 at 85 to 90 p.s.i., to the brake pipe and accelerate the build up of brake pipe pressure. As chamber 20 is connected to the brake pipe by passages 40, 39, 36 and 37, piston 16 moves back to connect the chamber 112 under piston 109 to atmosphere through passages 124, 70, 69, 148 and 149. Piston 109 then moves down, chamber 112 being then connected still to atmosphere by passages 124, 123, 125 and 130.