GB467216A - Improvements relating to fluid pressure braking systems - Google Patents

Abstract

467,216. Fluid-pressure brakes. KERSHAW, A. G., SIMMONS, A. W., and WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Dec. 14, 1935, No. 34783. [Class 103 (i)] In a fluid-pressure brake system for railway and other vehicles, the braking pressure exerted by one or more brake cylinders is controlled in response to pressure variations in one brake pipe, and the pressure exerted by a further cylinder or cylinders is con. trolled both in accordance with the pressure variations in this brake pipe and also in a further brake pipe extending throughout the train, the pressure in the further brake pipe being varied in accordance with the speed of the train. Figs. 1, 2 and 3 show the equipment on the locomotive, the tender and a carriage of a train, respectively. A vacuum train-pipe 3 control. led by the driver's valve 4 controls by,valves 19, 30, 8, compressed air brake cylinders 17 29, 5 for the locomotive driving wheels, the tender and the carriage. The valves 19, 30 8 are adapted to control the pressure in the cylinders ir accordance with the degree o: vacuum in the pipe 3. The carriages are also provided with a vacuum brake cylinder 1 controlled by the pipe 3. The supply reservoirs 18, 31 for the cylinders 17, 29 are charged from the main reservoir 12 through a reducing valve 20, the connection for the reservoir 31 being by the pipe 25 and non-return valves 21, 32 being interposed. Brake cylinders 22 for the leading bogie of the locomotive are controlled by the pressure in the pipe 33 leading to the cylinders 17, this pressure controlling a relay valve 24 by which the supply and exhaust of the cylinders 22 is effected, the supply being from the reservoir 12 through the reducing valve 20. An additional train-pipe 10 is, during an application -of the brakes, maintained at a pressure which is varied in accordance with the speed so that the higher the speed the greater is the pressure. This is effected by a relay valve 14 which supplies pressure to or releases it from the pipe 10 under the control of a speed responsive valve device 36. The supply to the pipe 10 through the valve 14 is from the reservoir 12 through a reducing valve 13 and the supply to the control chamber of the valve 14 through the valve 36 is from the reservoir 18. The pressure in the pipe 10 controls relay valves 7, 34, 35 interposed in the connections to one of the cylinders 17, 29 and 5, on the locomotive, tender and carriages whereby the pressure in these cylinders when the brakes are applied by reducing the vacuum in the pipe 3 is higher the greater the speed. The pressure in the other cylinders is independent of the speed and is preferably insufficient to lock the wheels. The pressure in the pipe 10 is maintained at a maximum when the brakes are released to permit this pipe to be used for charging the carriage reservoirs 6 by the provision of a valve 37 controlled by the pressure in the supply pipe 33 of the cylinders 17 so that when there is no pressure in this pipe, the control chamber of the relay valve 14 is connected through a double-check valve 38 and valve 37 to the pipe 50. The braking pressure may also be varied in accordance with the load of the vehicle. Thus, the hydrostatic pressure of the water in.the tank of the tender may control a valve 39 which controls the pressure in a relay valve 40 interposed between the valve 30 and the brake cylinders 29.