Patent GB-1156890-A (GB)
Title: Door Operating Mechanism
IPC: H02P7/00
Filed: 1967-10-12
Abstract: 1,156,890. Control of A.C. motors. STANLEY WORKS. 12 Oct., 1967 [15 Nov., 1966], No. 46585/67. Heading H2J. [Also in Division E2] An electromechanical door operating device comprises a reversible drive including a drive motor for powering a swinging door through door opening and closing cycles, and a traffic responsive control therefor, said traffic responsive control including a brake energized to hold the door in a closed position, a sensor for sensing door position, and electric circuit means responsive to said sensor for de-energizing the brake and for energizing said motor to return the door to closed position when the door is displaced therefrom in either direction. Switches are actuated respectively by traffic approaching the door in opposite directions, the motor operating as a brake to stop the door when both switches are actuated simultaneously and the door is displaced in the opening direction by less than a predetermined angle. The normal opening and closing cycle of the door is initiated by the closure of an approach switch 38 by traffic passing on to a carpet at the entrance. Relays A and C are energized to energize relay D through cam-operated position switches S3, S6, whilst relay J is de-energized to remove brake 12 and to energize the driving motor 16. As the door approaches its fully-open position, switch S4 is actuated to energize relay F whereby resistor 164 is shunted across motor winding 33a for operation at reduced speed. When the door reaches its fully-open position, switch S3 is actuated to de-energize relay D and to energize reverse door-closing relay I. The motor winding 33a is short-circuited to stop the motor, and relay J is energized, after a delay determined by resistor 172 and capacitor 174, to open the motor circuit and apply the brake, whereupon relay I is de-energized. For so long as traffic engages either the entrance carpet or a safety carpet on the other side of the door, the brake is applied and the door positively locked in the open position. When there is no traffic through the door-way, both switch 38 and safety carpet switch 42 are open to de-energize relay A. Relay C is deenergized after a time delay to energize reverse motor relay E through switch S2. The brake is removed to free the motor for rotation, full line voltage being applied to the motor which drives the door towards the closed position. As the door moves from the full-open position, switch S4 interrupts the supply to relay G which releases after a delay-period. While relay G is energized, the closure of switch 42 will cause the door to re-open. Further closing movement of the door causes relay F to be energized for a period to reduce the motor speed. If wind pressure tends to prevent complete closure of the door during the time delay provided by the relay F, full power is re-applied to close the door. At the closed position of the door, the motor winding 33 is short-circuited, the motor is disconnected, and the brake applied. After the relay G is de-energized, and before the door is fully closed, the door will open in the reverse direction when closure of safety carpet switch 42 energizes relay B. Relay F is energized for low-speed operation through the door-closed position until the door is opened a predetermined amount in the reverse direction whereupon relay B is de-energized and relay A is energized. As the door approaches the full-open position in the reverse direction, the motor is disconnected and braked as before. The door remains open if either switch 38 or 42 is closed. When both carpets are cleared, the door is re-closed. The motor will positively drive and locate the door at its closed position despite variations in wind pressure. If the door is driven past the closed position, the motor is braked electrically and then reversed. When the door is in the closed position and the touch control switch 19 is not opened, closure of switch 42 fails to initiate the opening operation until the traffic leaves the exit carpet. If, when the door is opening in a direction to sweep across the safety exit carpet and has moved less than 30 degrees, closure of switch 42 causes the door to be stopped by the motor and then become free-wheeling so as to be moved manually for passage of traffic. After the door has moved more than 30 degrees under these circumstances, closure of switch 42, causes the door to be reversed at low torque to open it in the other direction. If traffic then passes on to the entrance carpet, the motor is braked electrically and the door becomes free-wheeling until both carpets are closed, whereupon the door is closed. The relay G is energized when the door is opened beyond thirty and twenty degrees respectively in the process of opening or closing so that the door is moved to the open position to allow the passage of traffic in both directions. After the relay G is de-energized, closure of switch 38 causes the door to close at reduced power and then to open in the opposite direction. Emergency exit is provided by traffic passing on to the safety carpet to close switch 42 when the door is closed. The brake is released since the switch 19 is opened so that the door may be pushed manually for a short distance, whereupon the door is automatically opened under motor power. In the event of power failure, the brake is removed for manual operation of the door, a solenoid 117 being de-energized so that plunger 116 engages slot 115 when the door is closed to prevent rotation of cam washer 110. The door is moved against the pressure provided by spring washers 113 as the cam surfaces of washers 110, 112, rotate with respect to each other. Upon release of the manual pressure on the door, the mating cam-surfaces 111, 119, produce a torque to return the door to its closed position. A switch 19 requires contact with the door before the brake is released under emergency conditions. The system may be modified, so that the door will swing away from approaching traffic, by operating selector switch SS.