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:
Feb. 12, 1991
Filed:
Jul. 08, 1987
Jacques Lewiner, 92210 Saint Cloud, FR;
Claude Hennion, 75005 Paris, FR;
Other;
Abstract
An installation for controlling and monitoring the different coded locks of an assembly embodying: An issuer for elaborating coded keys for controlling said locks and a reader associated with each lock, adapted for unlocking this lock on simple presentation thereto of a correctly coded key, this issuer and this reader being adapted so that detection by said reader of the code y recorded by said issuer on each new key of order p assigned to the lock associated with this reader results in the invalidation of the code x recorded on the key of order p-1 previously assigned to this lock, each code y being derived from code x by an algorithm y=f(x) stored at least in the issuer. At any time the reader is responsive simultaneously to a number m greater than 2 of a non invalidated codes of the succession x, f(x), f.sup.2 (x) . . . f.sup.n (x) and is adapted so that by reading any one of these codes it automatically invalidates all the lower rank codes of the succession considered.