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:
Apr. 10, 1979
Filed:
Dec. 27, 1977
Rolf Willach, Au, CH;
Huwil-Werke GmbH, Mobelschloss- und Beschlagfabriken, Ruppichteroth, DE;
Abstract
An encoding circuit is provided permitting energization of an electromagnetic unlocking solenoid if a series of push-button switches is operated in accordance with a predetermined code. The circuit includes a memory which stores the sequence of operation of the push-buttons in accordance with the code in form of a binary code word. A comparison or decision stage is connected to the memory, typically a shift register, and connected to the memory position of all the digits of the code associated with the specific lock of a binary 1 value, as well as all the digits of the code in a binary 0 value, the decision circuit controlling the unlocking solenoid only if both the binary 1 and binary 0 values stored in the memory upon sequential push-button operation conform to the code associated with the lock, and, simultaneously, a timing circuit energized upon initiation of the first properly coded push-button still provides a timing energization signal, or operating energy to the circuit. In addition, the decision stage includes another input connected to a memory position, the value of which is unaffected by operation of the push-button switches so that additional safety against opening of the lock by trial-and-error operation of the push-buttons is provided.