GB186991A - Improvements in and relating to car control equipments - Google Patents

Abstract

186,991. British Thomson-Houston Co., Ltd., (General Electric Co.). July 7, 1921. Fluid-pressure.-Relates to air brake and safety car-control equipment for traction cars of the type in which the brakes are automatically applied when the operator moves his hand from the controller handle, or alternatively his foot from a combined cut-off and foot-valve at the operating end of the car and comprises an arrangement whereby the safety control features may be rendered inoperative so that the car may be used as a trailer, the brakes then being operated by the equipment on the head operating car. An arrangement is shown for preventing the release of the brakes until all the car doors are closed. The Figure shows the invention applied to a known double end air brake and safety car control equipment comprising a driver's brake valve 1, a motor controller 2, and a combined foot and cut-off valve 3 at. each end of the car, and a main reservoir 4, a triple valve 5, and a brake cylinder 6. The driver's valve has connected to it an emergency exhaust pipe 9, an emergency brake pipe 10, a straight air exhaust pipe 11, a straight air brake pipe 12, and a main reservoir pipe 13. The controller 2 is of the type in which the handle, when released, operates' a valve to vent a safety control pipe 15. The cut off valve 3 has a spring-pressed valve 24 which may be closed by pressing with the foot on a button 26. It is also closed when a straight application of the brakes is made by air from the pipe 12 passing a valve 28 and acting on a piston 27. The triple valve 5 functions in the usual way, the safety control pipe 15 being connected so that when it is vented a valve 22 opens the space 18 to atmosphere and brings about an emergency application of the brakes. A double check valve 35 and non-return by-pass valves 15' are provided for automatic actuation when the driver changes from one end to the other. The means for rendering the safety control features inoperative comprise a pipe 31 connecting the valves 3 and adapted to be connected by a three-way valve 30 either to the pressure reservoir 4 or to atmosphere. When open to the reservoir, the pressure acts on the pistons 27 to close the valves 24, the venting of the safety control pipe 15 being thus prevented when the handle 2 is released. At the same time the pressure moves a plunger in a cylinder 40 which opens a circuit-breaker 41 in the motor circuit. With this setting of the valve 30 the car is used as a trailer, the deadman handles 2 being inoperative, and the power cut off by the circuit.- breaker 41. The brakes will be operated by the driver's valve and safety control equipment on the head operating car through the pipes 10, 12. When however the valve 30 is set to open the pipe 31 to atmosphere, the deadman handles 2 become operative, and the power may be switched on so that the car may be used as an operating car. The arrangement for preventing the brakes being taken off until the car doors are closed comprises a magnet valve 32 which closes the straight exhaust pipe 11 when de-energized. A double throw over switch 36, door switches 33, and a train wire 37 are provided. When used as an operating car without trailer, the circuit is energized from the trolley 38 through the contact breaker 41, and is connected to earth through the switches 36, 33 as shown. When a trailer is used both switches 36 are thrown over. The circuit on the operating car, which is energized as before, then earths through the train wire 37 and the switches 33. 36 on the trailer car. In order that an emergency application of the brakes may be made at all times independently of the position of the doors each brake valve is arranged in its emergency position to establish communication between the emergency pipe 1C, and an exhaust pipe 9 opening to atmosphere.