Patent · US Expired

Releasable hoistway door safety interlock

US4469200A · kind A · utility

4Cited by
2References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 29, 1981
Grant dateSep 4, 1984
Priority date
Expiry dateOct 29, 2001

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T70/8946
  • WIPO fieldHandling
  • WIPO sectorMechanical engineering

Abstract

To prevent passengers in an elevator from opening the hoistway door when the car is well above the floor, a rotatable arm is located below the car and engages the hall door to prevent it from being opened. This arm may be reached from the floor, by opening the hoistway doors slightly, and rotated to disengage it from the door, which may then be fully opened.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.