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:
May. 05, 1987
Filed:
Mar. 20, 1986
Shinichi Aratani, Matsusaka, JP;
Tadashi Muramoto, Matsusaka, JP;
Central Glass Company Limited, Ube, JP;
Abstract
In toughening a glass sheet, e.g. for use as an automobile window, by heating it to a temperature above the strain point and quenching the heated glass sheet by blowing a cooling medium such as compressed air against both sides of the glass sheet from two opposite sets of nozzles, the cooling medium is caused to impinge on each side of the glass sheet in such a pattern that the glass sheet is more efficiently quenched and consequently more highly toughened in a generally circular central region and a plurality of generally annular regions, which are substantially concentrical about the center of the glass sheet and radially spaced from one another, than in the remaining regions. This is effective in preventing the presence of impermissibly elongated particles when the glass sheet is fractured and also in lessening the difference between the maximum and minimum numbers of particles in unit areas of the fractured glass sheet. For example, the desired pattern can be produced by arranging each set of the nozzles on a plurality of concentrical circumferences. Every nozzle may be directed perpendicular to the glass sheet or, rather preferably, tangentially inclined from the direction perpendicular to the glass sheet.