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Method for clearing unlocking key codes in an electronic locking device

  • US 4,868,914 A
  • Filed: 12/21/1987
  • Issued: 09/19/1989
  • Est. Priority Date: 12/21/1987
  • Status: Expired due to Fees
First Claim
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1. A method for clearing unlocking key codes in an electronic locking device for use with a door that is operable between an open and a closed position, the locking device being of the type that includes a central processing unit that stores first and second unlocking key codes, the locking device actuating when a code carried by a card is identical with an unlocking key code set in the central processing unit, the method comprising:

  • providing a first clearing card carrying a first code, for clearing unlocking key codes only when the door is in the open position;

    providing a second clearing card carrying a second code, for clearing unlocking key codes only when the door is in the closed position;

    determining whether the door is in the open or closed position;

    comparing the code carried by one of the first and second clearing cards with the first and second unlocking key codes in the central processing unit;

    clearing the unlocking key codes if the door is in the open position and the code carried by the one clearing card is identical to the first unlocking key code set in the central processing unit; and

    clearing the unlocking key codes if the door is in the closed position and the code carried by the one clearing card is identical to the second unlocking key code set in the central processing unit.

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