Patent · US Expired

Magnetic locking status detection system

US4516114A · kind A · utility

18Cited by
6References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 7, 1983
Grant dateMay 7, 1985
Priority date
Expiry dateMar 7, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG08B13/08
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

Magnetic door locks characteristically include a high strength electromagnet and a mating plate made of magnetically permeable material, or door strike, mounted on the door frame and the door, respectively. In addition, in order to determine whether the door strike is in engagement with the electromagnet, detection arrangements are provided; and in the present case, simplified detection arrangements are provided by separate portions of the electromagnetic core separated by non-conducting shims or the like, and the closing of a detection circuit extending between the two portions of the electromagnetic core by the magnetic and electrically conducting door strike bridging between the two sections of the core. In addition, the detection circuit may be electrically connected in parallel with electromagnet energization circuit, to positively indicate both that the electromagnet is energized and that the door is closed.

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