The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 15, 1980
Filed:
May. 26, 1978
Leonard J Genest, Santa Ana, CA (US);
Vache B Madenlian, Huntington Beach, CA (US);
Chromalloy Electronics Corporation, St. Louis, MO (US);
Abstract
A combination changing system and method for controlling access to a locked area and updating a lock combination or memory includes encoded key cards and storing lock code combinations in a memory. Each lock may be opened by a properly encoded key card. The lock code combination is automatically changed each time a new key card is generated and used. Specifically, first and second fields of a stored code combination are stored in an active memory of the lock and first and second fields of a key code combination to be compared therewith are encoded on a key card. When the key card is inserted into a card reader connected to the lock, two fields of the stored code combination are first compared with the two fields of the key code combination, respectively. If there is a match, an appropriate signal is generated to open the lock. If there is no match, the second field of the stored code combination and first field of the key code combination are compared. If there is a match at this second stage, an appropriate signal is generated to store the two fields of the key code combination in the lock memory in place of the two fields of the stored code combination.