Patent GB-765650-A (GB)
Title: Improvements in or relating to lift doors and their operation
IPC: B66B13/12
Filed: 1952-12-24
Abstract: 765,650. Operating lift doors. DEWHURST & PARTNER, Ltd., DEWHURST, M., WARD, A. J. C., and MINNS, G. E. Dec. 21, 1953 [Dec. 24, 1952], No. 32728/52. Class 65 (1). [Also in Group XXX] A lift system comprises a landing door having a beak which locks with a complementary part on the landing in the closed position and closes safety contacts which when the lift car is standing at the landing starts the lift car motor, the beak remaining in the unlocking position until it is moved into locking position as the result of operating a manual switch. The lift car door 1 is opened and maintained open by a motor 2 on the car operated by mechanism of the kind described in Specification 765,649. Mounted on the landing door is a channel member 9 rotatably supporting a spindle 10 carrying a pair of levers 11 mounting a wheel 12 and pivotally mounting a shaft 13 carrying a beak 14 biased by a spring acting on an arm 17 on the shaft 13 to engage a part on the landing wall contained in a box 19 to lock the landing. door. The beak has mounted a shorting bar 23 which bridges a pair of safety contacts 20 in the box. When the beak is rocked out of engagement the bar disengages contacts 24 and bridges a pair of sequence interlocking contacts 25 (not shown) in the box. Mounted on a rail 7 from which the car door is hung is a coupler 26. This comprises a fixed part 27 and a movable part 29 which is movable into contact with the wheel 12 both to lock the wheel to couple the car and landing doors and to rock the levers 11 to cause a rod 30 on the spindle 10 to engage a rod 31 on the shaft 13 to rock the beak out of engagement and free the landing door. The coupler is spring biased to coupling and is actuated to uncoupling by a solenoid 32 on top of the car. When the car door is opened, the coupler is disconnected from the solenoid, when the door is closed a lever projecting from the part 27 engages between flanges on the plunger rod 37 of the solenoid which when the solenoid is energized lifts the lever and the coupler is retracted to uncouple. In operation, when the motor 2 has been cut out and the doors have closed under bias, the bar 23 closes one set of contacts 25 when the up bush-button is pressed a circuit is closed for the winding of the solenoid relay energizing the solenoid causing the coupler to retract, uncoupling the doors and permitting the beak to engage the part in the box 19 opening on act of contacts and closing the other contacts 24 of the lower floor which closes a circuit for the lift car motor which is stopped when the car reaches the upper landing. The solenoid 32 is de-energized, causing coupling of the car and landing doors and unlocking the upper floor landing door and opening upper floor contacts 24 and closing the other upper floor contacts. The circuit for the motor 2 is completed and maintained by a timing relay closed for an interval by a dashpot. When the doors are opened one set of contacts open and the motor runs for the appropriate time then the doors close under bias. The car is similarly returned to a lower floor by pressing a door push-button.