GB374251A - Improvements in vehicle control for brake and door apparatus - Google Patents

Abstract

374,251. Controlling motorbus doors. NATIONAL PNEUMATIC CO., 420, Lexington Avenue, New York, U.S.A. May 26, 1931, No. 15423. Convention date, May 28, 1930. [Class 79 (v).] Means for controlling motor bus doors comprise pneumatic door-operating motors which cannot be operated to open the doors until the brakes are applied and while the doors are open the brakes cannot be released or the accelerator depressed. Further the doors cannot be closed until the doorway is clear of passengers. The vehicle is stopped by brake pedal 7 which operates valve 6 to pass fluid from a source 8 through pipe 4 to the brake cylinders 2. Fluid also passes through pipe 9 to operate pneumatic switch 10 and interconnect wires 22, 23. Current then flows through wires 20, 22, 23, 24 to switch 25 and through wires 23, 54 to stop lamp 55. When the bus stops the switch 25 is momentarily closed by the operator and current flows through wires 26, 27 to energize a magnet 33 and pull over a lever 31 which prevents depression of the accelerator 29. Current also flows through wire 26 to energize a magnet valve 36 and connect ports 110, 111, Fig. 3. This exposes a plunger 83 to fluid pressure and presses it against a valve seating thereby closing exhaust passage 81. When plunger 83 is seated a ball 82 of a check valve moves to the right against the action of a spring and exposes the cylinder of a pneumatic switch 12 to the fluid. The consequent movement of the piston bridges contacts 34, 70 and establishes a holding circuit for the magnet valve 36 so that it remains open after the switch 25 is opened. If a passenger is standing above one of the treadle switches 37 circuit 24, 70, 36<1>, 37, 38 is completed and a magnet valve 39 is operated to throw open the larger cylinder of the pneumatic dooroperating motor 41 to the atmosphere and open the door. Should an attempt be made to release the brakes while the doors are open by removing pressure on the pedal 7 to cut off the fluid supply, fluid under pressure will flow from the switch 12 through pipes 79, 5, 4. As soon as the treadles 37 are free magnet valve 39 is de-energized and fluid pressure is supplied to the large cylinder of the door engine to close the doors. As they close a drum 48 breaks the holding circuit of the valve 36 and establishes the circuit to the signal light 53 indicating that the doors are closed. The doors can be operated without a passenger standing on the treadle switch 37 by closing a switch 57. Further the doors can be opened from outside the motor bus by a key-operated switch 59.