GB468376A - Improvements in locking devices for doors or gates - Google Patents

Abstract

468,376. Locking doors of lifts. EXPRESS LIFT CO., Ltd., and COVE, W. J. Jan. 1, 1936, No. 65. [Class 78 (iii)] [Also in Group XXV] A locking device for the door or gate of a lift comprises a ratchet wheel rotated upon movement of the door &c., a pawl adapted to hold the wheel against rotation, and means at the floor served by the lift to release the wheel when the lift is at said floor. As shown, a collapsable sliding gate comprising vertical members 1 connected by lazytongs (not shown), suspended by rollers 2 running on a rail 3, is operated by a threaded motor-driven shaft 5 co-operating with an internally threaded part 61 carried on an extension 4 of the gate. The thread is of such pitch that whilst rotation of the shaft can move the gate, lateral movement of the gate can rotate the shaft. A ratchet wheel 7 carried by the shaft may be held against rotation by a pawl 8. As shown, the ratchet teeth are of such shape that the pawl. prevents clockwise rotation corresponding with opening movement of the gate, but allows movement in reverse direction. The teeth may be shaped so that the pawl prevents movement in both directions. The pawl is withdrawn from engagement by energization of a solenoid 14, the core 13 of which lifts a rod 12 so that its upper end engages a pin 11 on the pawl arm and rocks the pawl on its pivot 9. Hand release in emergency may be effected by rocking a member 30 on its pivot 31, the upper part of member 30 having a slot 33, one end of which engages a pin 34 on a depending arm 35 which moves with the pawl. Rod 12 has collars serving to rock arms 17, 18 carrying bridging contacts 19, 20 co-operating with pairs of fixed contacts 21, 22 for the purpose of indicating the state of the lock at a remote station. In an alternative arrangement the pawl forms one arm of a bell-crank lever, the other arm of which carries a roller co-operating with a cam in the lift well to rock the pawl out of engagement. An additional latch may be provided on the gate connected with the pawl by a link so that when the pawl is retracted the latch is also rendered ineffective. With a manually operated gate, closing the gate may raise a weight or otherwise store energy to be used for opening the gate when the pawl is released, and the screw-shaft may be threaded only near one end so that the ratchet wheel is rotated only as the gate is near the closed position. With a door arranged to rotate on a vertical shaft, the shaft carries a ratchet wheel cooperating with a pawl. With a motor-operated door a cam-operated or other switch may be provided for de-energizing the motor when the door is substantially closed, and for preparing door-opening circuits.