GB443966A - Improvements relating to fluid pressure braking apparatus - Google Patents

Abstract

443,966. Fluid - pressure brakes. SIMMONS, A. W., and WESTINGHOUSE BRAKE & SAXBY SIGNAL CO., Ltd., 82, York Road, King's Cross, London. Sept. 4, 1934, No. 25473. [Class 103 (i)] In a driver's valve an additional or fast service position is interposed between the service and emergency positions in which a circuit of an electromagnetic valve is opened by the movement of the driver's valve, to release fluid from the train pipe, this circuit is also open in emergency position but closed in release, running, lap and service positions. The electromagnetic valve 11 is adapted when de-energized to be seated on its lower seat by a spring 12 and connect a chamber 16 to a passage 14. The chamber 16 is connected by a check valve with a chamber 21 connected to the train pipe and the passage 14 is connected to a venting chamber 15. When the valve 11 is energized and raised it closes connection between the train pipe and the chamber 15 and connects the bulb 15 to atmosphere by passages 31, 32, chamber 28 and passage 29. In the event of the valve 11 becoming improperly de-energized, i.e. when the driver's valve is not in fast service or emergency positions and during an ordinary service brake application, a relay valve 26 is opened, when the train pipe pressure is reduced by the driver's valve, pneumatically, to connect the train pipe to atmosphere by chambers 21, 27, 28 and passage 29 to effect a full brake application. The pressure in the chamber 21 falls with train pipe pressure and causes the piston 19 to open the valve 26 only when the capacity of the chamber 16 has been increased by connection to the chamber 15 by the valve 11, the capacity of the chamber 16 alone being insufficient to effect movement of the piston 19. When the valve 11 is improperly de-energized in running or release, a brake application is produced by connection of the train pipe to the bulb 15. The bulb 15 may have a restricted atmospheric port, or the bulb may be dispensed with and the valve 11 may connect the train pipe to atmosphere.