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:
Dec. 11, 1990
Filed:
May. 15, 1989
Michael A Loda, Hanover Park, IL (US);
Other;
Abstract
Generally there is provided a cabinet alarm device having a protruding switch lever arm arranged such that it is held open during closure of a cabinet door, but is allowed to close when the cabinet door is opened. The switch is pivotally mounted and urged toward its closed positionby a spring under tension, such as a rubber strip or O-ring fixed to the switch arm and alarm case. This switch controls power to the electronic circuit which includes two oscillator and two controlling comparators. A first oscillator drives an annunciator at a preset high resonant frequency, while a second oscillator operating at a low frequency pulsates the tone. A first controlling comparator circuit operates to disable the tone circuit after a fixed time delay to allow an audible battery check during that delay but preventing further tone unless the circuit is energized for a longer period. A second controlling comparator disables the first comparator and thereby enables the alarm circuit after a preset longer delay or upon detection of sufficient multiple operations.