Patent · US Expired

Tamper-proof door switch and latch device

US5520424A · kind A · utility

55Cited by
4References
27Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 30, 1995
Grant dateMay 28, 1996
Priority date
Expiry dateJan 30, 2015

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T292/702
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

In a door latching and switch contact controlling device, an actuator having first and second radially extending angularly spaced apart members is mounted on a common shaft in a housing with a latching member for the member and actuator to rotate together. A striker fastened to a door strikes the first radially extending member when the door closes to turn the actuator so the second member rotates into an opening in the striker to thereby conceal the first member. An electroresponsive device positions a latching element into the path of a stop on the latching member when the device is energized, thereby preventing the actuator from turning reversely if an attempt is made to open the door. The device locks the door if it is closed, if the actuator is rotated by the striker and the electroresponsive device is energized, whereupon a pair of contacts are compelled to make contact to complete a circuit for signalling a controller that it can initiate existence of a hazardous condition that is prevented from being accessed by the locked door.

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