Patent GB-749935-A (GB)
Title: Improvements in devices for the automatic opening and closing of doors and the like
IPC: E05F15/624
Filed: 1954-03-10
Abstract: 749,935. Door-operating apparatus. BUNZL, H. H. March 10, 1954 [March 13, 1953], No. 6945/54. Class 65 (1). [Also in Groups X and XXXVII] A reversible electric motor is mounted on the door, which may swing, slide, or revolve, and drives a roller which is pressed against the floor or stationary track so that its rotation moves the door, means controlling the motor being actuated in dependence on the movements of the door. The roller, which may be toothed and engage a fixed rack, is preferably driven through a friction clutch to allow movement of the door by hand, and means are provided for lifting it from the floor or track; the device may be arranged at the top of a door. The switch by which the opening of the door is initiated may be actuated (mechanically or by electrical, pneumatic or hydraulic transmission) by a finger switch in the door frame, a footoperated switch, or photo-electric or other electronic control means; movement of the door by hand in the opening direction may cause the motor to start, or to reverse if the door is being closed. The motor may reverse immediately the door reaches the fully-open position, or the initiating device may be locked in the actuated position to delay closing. When applied to revolving doors, each operation of the starting switch preferably produces half a revolution of the door. The control circuits are arranged so that the door is slowed down during the later part of its opening movement, the closing movement is slower than the opening, and an increased final closing force is applied. In the form shown, for a hinged door, the motor 9, arranged in a casing 7 fixed to the door, drives through gearing a spindle on which is pivotally mounted an arm 11 carrying the roller 17, the arm containing gearing for driving the roller and being pressed downwards by a spring 18; the motor is adjustable about its own axis so that the axis of the roller may be placed to intersect the hinge axis of the door. A shaft 26 actuating switches controlling the motor has an extension bevel-geared to a vertical spindle arranged near the hinge of the door and rotated, as the door moves, by a telescopic arm hinged to the door-frame; the shaft extension may be fitted to either end of the shaft 26 according to the hand of the door. The shaft 26 frictionally actuates an arm 44 whereby a switch 47 is reversed at the beginning of each door movement, and carries cams 27 actuating other switches 38 ... 42 at predetermined positions of the door. Operation of the starting switch 4 causes energization of a relay 24 through 39, closing a holding circuit for 24 through 47 and 24b and a circuit for a relay 25 through 24a and 40 to start the motor 9 for opening the door through 25d, 38, 25b, 25a. 47 is immediately reversed, holding 25, and after a predetermined movement of the door 38 is operated to slow the motor by inserting resistance W1; movement of the door by hand actuates 47 to start the motor without using the switch 4 and relay 24. 39 is actuated during opening to render subsequent operation of 4 ineffective, and 41 and 42 are also actuated to prepare a closing circuit. When opening is complete 40 is actuated to de-energize 25 and start the closing movement of the motor through 47, 40, part of resistance W2, 25a, and 25b. The immediately-following reversal of 47 results in the whole of W2 being inserted in the circuit, which now passes through 4, 25c, 42, and 41 reversed. When the door is nearly closed 41 is actuated to cut out W2 to increase the closing force, and immediately before complete closing 42 is actuated to stop the motor. Closing may be delayed by keeping 4 in the opening position. In a modification the relays and resistances are dispensed with, one cam on the shaft actuating a reversing switch to start the closing movement while a second cam opens a circuit-breaker after the door is closed; the closing speed may be regulated by an adjustable resistance.