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Combination lock monitoring system

  • US 4,453,390 A
  • Filed: 01/06/1982
  • Issued: 06/12/1984
  • Est. Priority Date: 01/14/1981
  • Status: Expired due to Fees
First Claim
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1. A monitoring system for a combination lock which includes a first apertured, rotatable combination wheel, a withdrawable lock bolt mechanism, and a lock drop arm enterable within the aperture in said wheel to permit withdrawal of said bolt mechanism, said monitoring system comprising two optical sensors each incorporating an LED and a light sensing detector fixed with respect to the combination lock and focused on respective regions of the combination lock corresponding to a face of the rotatable combination wheel and a location occupied by a part of the lock bolt mechanism when withdrawn or otherwise by part of the lock drop arm when not entered within the aperture of said wheel, said face of the combination wheel having both light reflecting and non-reflecting areas and said parts of the lock bolt mechanism and said lock drop arm each having an area one of which areas is light reflecting and the other is non-reflecting, and electronic means responding to the combined response state of said optical sensors to provide an indication of the operated condition of the combination lock.

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