Patent GB-485094-A (GB)
Title: Improvements in vehicle door control system
IPC: E05F15/00
Filed: 1936-11-11
Abstract: 485,094. Door control systems. NATIONAL PNEUMATIC CO. Nov. 11, 1936, No. 30820. Convention date, July 7. [Class 65 (i)] In a door control system for vehicles or lifts, including power operating means for the doors and means for reversing the movement of a door if it strikes an object in closing, the reversing means is maintained in an operative condition for a period of time after the door is fully closed and is rendered ineffective on the attainment of a predetermined condition incident to the operation of the vehicle, e.g. on reaching a certain speed or by the change from first to second gear. Means may be provided to prevent starting of the vehicle while any door is open. In the arrangement shown in Fig. 1, the door is controlled by a device 15, e.g. an electromagnetic switch or valve, its circuit being completed to open the door by a passengers' treadle switch 16 and a control switch 8, which may be actuated by another door ; a signal device 28 is energized in parallel with the control device 15. A reversing switch 13 controlled by a sensitive door edge can also complete a circuit to open the door, but when the vehicle attains a certain speed its propulsion motor 1 energizes a winding 3 to open a contact 4 to render the switch 13 ineffective ; the contact 4 is held open by a winding 11, of insufficient strength to operate it, until the circuit of the latter winding is broken by a new operation of the switch 8. In a modification, the winding 11 is replaced by a stick relay having a normally-open contact in series with the contact 4, picked up by the switch 8. The contact 4 may be closed by a centrifugal switch or by the gear lever of the vehicle instead of the means shown. Fig. 8 shows a control system for a vehicle having front and rear doors operated by pneumatic engines FM, RM respectively, the front door being controlled bv a driver's valve V and the rear door by an electromagnetic valve 15. The front door actuates a switch FS which prepares a circuit for treadles switches 16 to open the rear door, the valve 15 being maintained energized through the speed control contact 4, a switch RS actuated by the rear door, and a resistance 85 which prevents operation of the valve 15 by means of this circuit; the holding circuit of the valve 15 includes an electromagnetic valve 89 for applying the brakes and a switch S which is closed when the brakes are applied to short-circuit the valve 89 ; this arrangement preventing full release of the brakes if the rear door is not closed, or applying them when the door starts to open. The switch FS also breaks the circuit of the coil 11 of the switch 4 and the traction motor (lead 74), which circuit is further broken by the switch RS when the rear door opens ; a signal device 99 indicates when this circuit is complete. When the rear door is fully open the circuit of the valve 15 is broken by the switch RS and the door starts to close ; if it strikes any object in closing, the reversing switch 13 is closed to re-energize the valve 15 to cause the door to reopen. In a vehicle having an internal - combustion engine, the control of the contact 4 by the propulsion motor is replaced by contact, in series with the contact 4, operated by the gear lever, and an electromagnetic valve energized when the circuit for opening the rear door is prepared may bring into action means for maintaining the brakes applied and means for locking the accelerator.