Patent GB-191230036-A (GB)
Title: Improvements in or relating to Locking Devices for Lift-gates and the like.
Inventor: ANDREW HUGH FREDERICK
IPC: E05B65/00
Filed: 1912-12-31
Granted: 1913-12-24
Abstract: 30,036. Andrew, H. F. Dec. 31. [Cognate Application, 15,104/13.] Lift cages and doors, locking and unlocking. -Comprises a lock for lift gates in which a tripping or releasing device is mounted normally clear of a member carried by the cage, but such that when the cage is at a floor, an attempted operation of the gate-unlocking means brings the tripping-device into engagement with the member on the cage to allow the gate to be released, the movement of the gate-unlocking means being ineffective when the cage is absent. A switch in the control circuit is combined with the above-described device. In the form shown in Fig. 1, a fixed catch 2 on the gate engages a pivoted catch 5 in the housing 4. Pivoted at 16 is a bell-crank 14, 15 carrying at 17 another pivoted bell-crank 18, 19, of which the arm 18 engages a tail-piece on the catch 5. A switch member 7 is pivoted to the catch lever 5, the arm 8 engaging between the catch 2 and a stop on the housing. When the handle 13 is operated to unlock the gate, the part 12 engages the lever 14, 15, causing the lever 18, 19 to rock idly about its fulcrum. If the cage is present at the floor, the movement of the arm 19 is restricted by the member 20 on the cage, and the arm 18 lifts the catch 5, unlocking the gate and breaking the control circuit. The part 21 may be pivoted to the arm 19 and constrained by springs to take up normally the position shown, so that, if the cage is not at rest when parts 20, 21 engage, a rocking of the part 21 about its pivot ensues, and the gate cannot be unlocked. Fig. 4 shows diagrammatically a modification in which the tripping-member comprises a flap 23 pivotally mounted on the cage. The flap is adapted to come between levers 25, 26 when the cage is at a floor, and operation of the handle 13 then causes the latch 6 and a switch (not shown) to be released. Figs. 6 and 7 show a modification in which a pivoted latch 28 on the gate is engaged by a locking-piece 30. A spring 31 carried by a lever 32 engages a sneck on the piece 30, so that when the handle 13 is operated to lift the latch, the part 30 moves up with it and prevents its withdrawal. When the cage is present, the movement of the part 30 is restricted by engagement of the ramp 20 with a lever 33, and the latch may be withdrawn. The latch enters between arms 34 on a weighted part 35 carrying switch members Fig. 9 shows the. device applied to a lift with a vertically sliding shutter. Latches 40, 42 engage, and movement of the door 37 upward results in an idle movement of the lever 45 which is carried by an arm 38 pivoted to the shutter. When this is restrained by the presence of the cage, the catch 40 is released. The catch 40 enters into a forked switch member 43. A stop 44 limits the movement of the shutter 37 when the cage is absent. In a modification of the device shown in Fig. 1, a spring engages a lug on the lever 5 to force it up and break circuit when the catch 2 is removed. In a further modification, insulated contacts are carried by the catch 2 and by a lug on the catch lever 5.