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:
Feb. 19, 1991
Filed:
Dec. 01, 1989
Harry S Koontz, Pittsburgh, PA (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
An electric field detector for a heatable windshield includes detector lines which extend around a portion of the perimeter of the windshield between the edge of the windshield's electroconductive coating and the leads to one of the windshield bus bars and are electrically insulated from the coating, bus bars and leads. The detector lines are electrically interconnected to the coating by a tab at a predetermined location between the bus bars. As electrical current passes through the coating, voltage in the coating at the predetermined location is monitored and the current to the coating is interrupted in response to predetermined variations in the measured coating voltage.