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:
Mar. 23, 1993
Filed:
Dec. 20, 1991
Evert Nieuwkoop, Pijnacker, NL;
Chubb Lips Nederland bv, Dordrecht, NL;
Abstract
An electronic lock is constructed to resemble the appearance and functionality of a conventional cylinder lock. Its key has a bit in which is mounted an integrated circuit chip storing the key code and including a transmission coil for inductive coupling with a reading head in the lock. The latter includes a coil for generating a high frequency alternating magnetic field across a localized region of the keyway concentrated via a toroidal ferrite core structure which defines a gap spanning the keyway through which the chip passes when the key bit is inserted. This core structure includes a U-shaped part in the stationary lock housing around which the coil is wound, and two parts mounted in the barrel, one to either side of the keyway, which register with the part in the housing when the barrel is in the key-reading position. Further ferrite pads may be mounted to either side of the coil in the key itself, to register with the ferrite parts in the barrel. By virtue of this core structure, optimum flux coupling between the lock and key may be achieved, thereby minimizing power consumption.