04313525 is referenced by 14 patents and cites 6 patents.

The power operated sliding door of an elevator car is provided with a mechanical safety interlock which permits the car door to be moved more than a critical distance from its closed position only when the car is in a landing zone. A pivoted interlock hook on the car door has a normal position in which it engages an interlock lug on the car frame when the door moves the critical distance from closed position. A movable element on the car door is driven to move the hook to a clearance position relative to the interlock lug. Drive of the movable element occurs when it contacts an interengaging member on the hatch door as the car door first starts to move from closed position in a landing zone.

Title
Car door safety interlock
Application Number
6/156771
Publication Number
4313525
Application Date
June 5, 1980
Publication Date
February 2, 1982
Inventor
Emory W McDonald
Geneseo
IL, US
Agent
Wegner Stellman McCord Wood & Dalton
Assignee
Montgomery Elevator Company
IL, US
IPC
B66B 13/00
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