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. 19, 1983
Filed:
Oct. 17, 1980
Terry A Keifer, Pottstown, PA (US);
Check Mate Systems, Inc., King of Prussia, PA (US);
Abstract
A product monitoring device including a releasable locking device adapted to be secured to a product and actuatable between locked and unlocked positions. The locking device consists of a pair of movable members, one of which mounts a bimetallic member consisting of bimetal elements having different temperature coefficients of expansion, the bimetal elements being separated by an insulator. The locking device includes a detent cooperatively associated with the bimetallic member to maintain the members in a locked position. The device uses an electrifiable key for heating the bimetallic elements to effect displacement thereof relative to the detent to facilitate movement of the members to an unlocked position. The device incorporates structural features which increase strength in operation, and further serve to make unauthorized opening and/or breakage of portions, with the intent of permitting separation from an article to which attached, more difficult. Opening without use of the key is additionally more difficult in the improved device.