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:
Jun. 04, 1991
Filed:
Jan. 22, 1990
Paul J Kovacik, Ford City, PA (US);
Charles R Davidson, Natrona Heights, PA (US);
Kevin B Lindsay, Marshall, MN (US);
Darrel V Lundberg, Marshall, MN (US);
Cameron A Mulder, Minneota, MN (US);
Everett Boerboom, Amiret, MN (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
An insulated glass unit formed from a pair of glass sheets, one of which has an electroconductive coating, i.e. a first sheet, is fabricated by positioning the first sheet on a vacuum support and the other sheet, i.e. second sheet, spaced above the first sheet a sufficient distance therefrom to prevent arcing during electrical heating of the marginal edges of the second sheet. After the marginal edges of the second sheet are heated to a temperature sufficient to cause sagging of the marginal edges, the two sheets are brought together to join the marginal edges by fusion. A strip heater heats the edges of the sheet to a temperature sufficient to prevent chilling of the marginal edges of the upper sheet when contacting the marginal edges of the lower sheet. Thereafter, the sheets are separated from one another and air moved between the sheets to bloom the edes. After blooming the edges, the joined glass sheets are annealed, and an insulating gas moved into the airspace through a pore hole. Thereafter the pore hole is sealed.