Patent GB-281765-A (GB)
Title: Improvements in apparatus for operating and controlling the doors of tramway or like vehicles
IPC: E05F15/56
Filed: 1926-09-08
Abstract: 281,765. Peters & Co., Ltd., G. D., Hockley, H. R., and White, H. B. Sept. 8, 1926. Operating and controlling doors electrically and pneumatically and by treadles and the like.-In a system for operating and controlling the doors of an electric tramway car or other electrically propelled vehicle the control by the driver of the operations of the apparatus to open and close the doors is effected, under normal running conditions, solely by movements of the main traction controller handle, the movements of which also effect the application and release of the electric or other brake of the car or vehicle, and make and break the circuits of the electromagnetically-actuated valves controlling the supply of compressed air to the door motors. Specifications 254,347 and 262,854 are referred to. In the control system, shown diagrammatically, each pneumatically-operated door-engine 1 is controlled by a valve 2 with a valve-puller 3 that is supplied with compressed air from the main reservoir and water trap 4 through suitable valves. The compressed air reservoir is directly connected with an electropneumatic-valve device A, which controls the supply of air to the pipe 5. The wiring diagram of the system includes electromagnetically-operated valve devices 14 and 10 for the valve-pullers 3 and device A respectively, treadle-operated contacts 16 for the exit doors, a change-over swith 15 at each end of the car under the control of the driver, positioned at 25, an electrically-operated interlocking switch 17, shown more particularly in Fig. 1 (Comp.), traction-controller drum switches 18, and a control governor 19 that serves to break the electric feed to the main controllers when compressed air is not available. The switch device 17 comprises coils 17a, 17<b> with fixed covers 42, 43 and movable plungers 32, 33 which, when the coils are energized, move pawl levers 34, 35 to produce a rotational movement of a ratchet wheel 38 and its contact drum 39. Assuming the car to be travelling to the left, with the left-hand change-over switch 15 being closed as shown, on the traction-controller handle carrying the switch drums 18 being moved halfway towards the first notch of the power position, a circuit is completed at the contacts 44, 45 and current is caused to flow across the fingers 21, 20 and thence through the coil 17. The core 32 is attracted, the lever 34 raised and, through the pawl 34<a>, the ratchet wheel 38 and contact drum 39 are turned through 18‹ in an anticlockwise direction. This causes the circuit of the power coil 17<a> to be broken and also breaks the contacts 22, 23 connected to the line. On moving the controller handle further into brake position, contact is made by the contacts 46, 47 of the drum 18 so that current flows through the brake coil 17<b> to move the core 33 and the pawl lever 35 into a raised position. Subsequent movement of the controller handle past the brake notch causes the coil 17 to be de-energized, when the weight 48 depresses the pawl 35<a> and causes the ratchet wheel 38 and drum 39 to be further rotated through 18‹ in an anticlockwise direction. The contacts 20, 21 for the power coil are thus re-made and the lower contacts 22, 23 made for the line. In this position, the circuits of the electropneumatic valves of the appropriate doors for the direction of running are completed to open the entrance door and, if the treadle switch 16 is closed, the exit door. To close the doors the controller handle is moved into power position and the coil 17<a> energized, the drum 39 being moved to break the circuit at 22, 23 and deenergize the electromagnets of the valves 14. With the valves 14 in this position, compressed air is admitted to the valve-pullers 3 to admit compressed air to the door engines 1 to hold the doors closed, the doors being opened only when the valve devices 14 are energized and the valve pullers 3 placed to exhaust. The supply of compressed air from the reservoir 4 to the pipe line 5 is under the control of the electromagnet 10 of the valve device A. When the coil 10 is energized its core 11 is held in a position to close the admission of air to the piston chamber 30, the valve 9<a> being unseated by the spring 8 to open communication between the reservoir 4 and the pipe line 5, the valve 9 closing the exhaust pipe 12. Failure of the line current results in the coil 10 being de-energized, its core 11 then dropping and admitting air to the piston 31 to force it to the left to unseat the exhaust valve 9 and, by closing the valve 9<a>, cutting off the supply of compressed air to the pipe line 5 and door engines. A cock 13 serves to isolate the door motors when this is required. A deadman's handle may be furnished in connection with the controller handle.