GB1498039A - Lift systems and landing door lock auxiliary release mechanisms therefor - Google Patents

Abstract

1498039 Lift door lock mechanism BENNIE LIFTS Ltd S E KRUGER and A E GOTTS 7 March 1975 [8 March 1974] 10574/74 Heading B8L In a lift system, the landing doors 17, 18 of the lowest two levels in a lift shaft 16 each have a door lock release mechanism 29, 30 actuable by an electrically operated solenoid 13, in addition to a mechanical cam and roller 10 actuation effected by the lift car 22 arriving at a floor level, this electrical operation enabling the lift car to be sopped in maintenance positions adjacent the ground and first floor levels. Manually operable switches 19, 20 associated with respective lock release mechanisms 29, 30, are situated either in the lift car, in the motor room or at the respective landing level, and are operable via security devices, by authorized persons only, these switches operating the solenoids of respective lock release mechanisms 29, 30 whereafter the respective landing doors 17, 18 may be manually opened. In a modification, Fig. 4 (not shown), a second switch (27) either on the lift car or mounted in the lift shaft and set in series with the switch (19) or (20) in the circuit of each release mechanism, has to be closed before the associated door lock release mechanism solenoid can be energized. This closing is effected either by control cams, in the shaft, or by control cams on the lift car, as the car reaches the appropriate position in the shaft. A warning lamp may be set in series with each switch (27) to indicate the switch operating position of the lift car. The switches (27) may alternatively be operated magnetically or optically. In further embodiments, Figs. 6 and 7 (not shown), the switches (19, 20) are set in series with safety contacts (32, 33) to prevent movement of the lift car when one of the switches (19, 20) has been operated, or the switches (19, 20) may be further interlocked to prevent each lock mechanism being released unless the lift car has stopped.