GB464780A - Improvements relating to vacuum braking apparatus - Google Patents

Abstract

464,780. Fluid - pressure brakes. KERSHAW, A. G., SIMMONS, A. W., and WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Oct. 24, 1935, No. 29367. [Class 103 (i)] In automatic vacuum-brake apparatus communication between the lower chamber of the brake cylinder and the train pipe or atmosphere is electrically controlled by the driver and communication between the upper chamber of the brake cylinder and the atmosphere is automatically controlled by the retardation produced by the braking. The lower chamber 15, Fig. 2, of the brake cylinder 11 is adapted to be connected to the atmosphere by an application valve 9 to apply the brakes and to the train pipe 1 by a holding valve 10 which is closed to hold the brakes applied. A blowdown valve 20 is adapted to connect the upper chamber 23 of the brake cylinder 11 to atmosphere to release the brakes and is controlled by a retardation pendulum 34. To apply the brakes the manual controller 3 is operated to energize the application wire 4, and valves 9, 10 from the supply wire 31. The valve 9 on each vehicle of the train is opened and valve 10 closed to apply the brakes. To hold the brakes applied controller 3 is moved to de-energize wire 4 and valves 9 and valves 10 are maintained closed, valve 10 by energization of the other coil 14 by the holding wire 5. While the brakes are being applied, the retardation may be sufficient to cause the pendulum 34, Fig. 1, to swing away from contact 35 to engage contact 40, whereupon coil 36 of a contactor 38 is de-energized to de-energize the application wire 4 and application wire 5 is energized, thus holding the brakes applied. Further retardation causes the pendulum to leave contact 40 to engage a contact 41, thus de-energizing contactor 39 thus de-energizing the blow-down wire 7 and the blow-down valves 20, Fig. 2, which open to connect the upper chambers 23 of the brake cylinders 11 to the atmosphere, and also close the connection between the chamber 15 of the brake cylinder and the train pipe. The train pipe 1 is adapted to be connected to atmosphere to give pneumatic brake application by deenergization of valve 46 which is normally energized by connection to supply wire 31 by controller 3. This connection is broken on movement of controller to application position but energization is maintained by interlock wire 8, circuit through which is completed by contact 50 of valve 10 and contact 51 of valve 20, and a connection 52 to train wire 6 leading from supply wire 31. If valve 10 or valve 20 fail the valve 46 is de-energized by contact 50 or 51 and a pneumatic application takes place. An additional brake cylinder 53 is controlled by the valves 9, 10.