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:
Oct. 25, 1994
Filed:
Sep. 28, 1992
James S Murray, South Lyon, MI (US);
Stanley Home Automation, Novi, MI (US);
Abstract
A group of cabinets or other units each have a solenoid operated lock controlled by an electronic lock accessible by one or more electronic keys. The locks are linked together in a chain by power and data lines so that power is supplied through a single 12 volt transformer, and key codes are transmitted from a lock that reads a key to other locks, to open any cabinet programmed with an access code matching the transmitted key code. To limit power requirements, when one solenoid is being energized a busy signal is transmitted to prevent concurrent operation of other solenoids. A user installed master code stored in the lock and a corresponding master key are used to permit programming or erasing of other access key codes. A factory installed permanent reset code is stored in the lock and a secret algorithm known only to the manufacturer can derive the reset code from the cabinet serial number. When a master key is lost the user requests a reset key from the manufacturer who must use the secret algorithm to reveal the reset code and make a key containing the reset code. When that key is used, the master and access codes are erased, the lock is opened and the code in the reset key is scrambled to prevent its use for another reset operation.