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. 14, 1980
Filed:
Feb. 06, 1978
William C Cooke, Kingsport, TN (US);
AFG Industries, Inc., Kingsport, TN (US);
Abstract
A tamper-proof transparent security plate has a laminated structure of a break-resistant, normally transparent plate member which becomes opaque upon forceful penetration and a transparent alarm plate containing a plurality of frangible electrically conductive wires extending across an area to be protected. Efforts to break the laminated structure render it opaque, making it extremely difficult to locate and tamper with the wires of the alarm plate. Moreover, a selected subset of the wires can be excluded from a series alarm grid to further thwart efforts to bypass an associated alarm circuit. In a preferred embodiment, the voltage applied to the wires is adjustable to provide an optional heating, de-icing, or defogging capability.