04947964 is referenced by 35 patents and cites 11 patents.

An apparatus for opening and closing the car door of an elevator car which is situated in the door opening zone of a floor is coupled together with a shaft door, and is driven automatically by a drive motor or, in the case of a power failure, manually by a passenger. If the elevator car is situated outside a door opening zone, the car door remains locked by the same apparatus. The car door is driven through a drive belt by way of an entraining parallelogram linkage, which linkage includes a rigid cam and a movable cam and is mounted at the upper part of a car door. For free travel through a door opening zone, the linkage is closed, and the linkage opens for the coupling with the shaft door between two coupling rollers mounted on the shaft door before a movement of the doors takes place. The movable cam includes a compressible ramp cam which, during the travel and on stopping outside a door opening zone, lifts off from a rigid cam carrier due to leaf springs. On the coupling with the coupling rollers of a shaft door, the ramp cam is pressed against the rigid cam carrier for the unlocking of a car door bolt. The linkage is connected to the drive belt by an actuating lever which cooperates with a pair of abutments to define the open and closed positions of the linkage.

Door drive apparatus with locking mechanism for elevators
Application Number
Publication Number
Application Date
March 13, 1989
Publication Date
August 14, 1990
Josef Husmann
Marshall & Melhorn
B66B 13/00
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