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:
Jan. 06, 1998
Filed:
Jan. 22, 1996
Robert F Tweadey, II, Farmington Hills, MI (US);
Kenneth J Gajewski, Woodhaven, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A glazing unit has a tempered glass pane or other frangible glazing pane carrying a glazing pane breakage detector assembly. The detector assembly includes spaced first and second electrically conductive bus pads formed of electrically conductive material on a surface of the glazing pane. An electrically resistive trace on the surface of the glazing pane is formed of electrically resistive material different from the electrically conductive material of the bus pads. The resistive trace establishes a non-short electrical interconnection between the bus pads, which can be formed of highly conductive material, such as silver-filled paint currently in widespread commercial use. Such bus pads afford a structurally sound attachment, with good electrical contact by soldering, electrically conductive epoxy or the like upon which upstanding attachment tabs are secured. Electrical leads can be attached to such upstanding tabs to connect the detector assembly to suitable security circuitry. The resistive trace is fragile, such that security circuitry can detect and respond to loss of electrical connection between the bus pads upon fracture of the glazing pane underlying the resistive trace. Security circuitry also can detect a change in the resistance of the electrical connection between the bus pads, such that security is not defeated by a jumper cable between the bus pads. The resistance value of the resistive trace between bus pads can be varied from one glazing pane to another to further enhance security.