04364454 is referenced by 12 patents and cites 13 patents.

A locking mechanism, for the doors of an elevator car, which is disabled when the car is within a short distance from a landing but which otherwise permits the doors to be opened by an amount insufficient for a passenger to exit from the car and then locks the doors with respect to further opening movement. In the preferred form, a door carries a notched plate, and a latch bolt on a part of the car which is stationary relative to the door is controlled by an arm engageable with spaced cams in the hoistway so that the bolt will enter the notch of the plate when the car is away from a landing and the doors are partially opened.

Title
Vehicle door lock for limiting door opening to specified vehicle positions
Application Number
6/201307
Publication Number
4364454
Application Date
October 27, 1980
Publication Date
December 21, 1982
Inventor
Herbert P Glaser
Demarest
NJ, US
Walter Glaser
Montvale
NJ, US
Agent
Brooks Haidt Haffner & Delahunty
Assignee
G A L Manufacturing Corporation
NY, US
IPC
B66B 13/00
View Original Source