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US 4,165,228 AGranted
Process and apparatus for heat treating edge of plate glass
AssigneesAgency of Industrial Science and Technology, Central Glass Company, Limited
InventorsYoshihiro Ebata, Tsutomu Ueno, Nagamasa Kataoka, Akimasa Akao
Life of this patent
Estimating the term…
Abstract
The edge portion of a plate glass is locally heated to a temperature higher than that in the other portion of the plate glass, after the whole of the plate glass is heated. Electric current is thereafter applied to the edge portion of the plate glass in order to further heat the edge portion so that the edge of the plate glass is slightly melted.
Claims18
A process for treating an edge of a flat plate glass, comprising:
- heating the whole of the plate glass to a first temperature;
- heating only a straight and elongate edge portion of the plate glass including the edge to a second temperature higher than that in the other portion of the plate glass and lower than the softening temperature of the plate glass, said second temperature being higher than said first temperature, said heating the edge portion being carried out by using a straight and elongate heating unit disposed along the edge portion of the plate glass, said heating unit being located spaced apart from and near the surface of the edge portion;
- applying electric current to the edge portion of the plate glass through a pair of electrodes which are contacted to both side surfaces of the edge portion, respectively, thereby to raise the temperature in the edge portion to the softening temperature of the plate glass.
An apparatus for treating an edge of a flat plate glass, comprising:
- supporting means for supporting the plate glass;
- first heating means for heating the whole of the supported plate glass to a first temperature;
- second heating means for heating only a straight and elongate edge portion of the plate glass including the edge to a second temperature which is higher than that of the other portion of the plate glass and lower than the softening temperature of the plate glass, said second temperature being higher than said first temperature, said second heating means including a straight and elongate heating unit secured to said supporting means along the edge portion of the supported plate glass, said heating unit being located spaced apart from and near the surface of the edge portion;
- a pair of electrodes contacted to both side surfaces of the edge portion of the plate glass, respectively, which both side surfaces are opposite to each other, said electrodes being supplied with electric current to raise the temperature in the edge portion to the softening temperature of the plate glass.
1 more element
Dependencies are inferred from the claim text.