Patent ID: 7856851
Filing Date: 2010-12-28
Classification: C03B,Y10T

Abstract:
1. A process for bending a glass panel, comprising: a first step of bending the glass panel by making said glass panel sag under gravity on a first support, giving said glass panel a first central sag; then a second step that continues the bending and that includes contacting said glass panel to a second support thereby bending the glass panel by sagging under gravity, on said second support, giving said glass panel a second central sag more pronounced than the first central sag and until the entire periphery of the glass panel comes into contact with the second support, a third step that continues the bending and that includes maintaining the glass panel on the second support at a sagging temperature high enough for the central part of the glass panel to continue to sag after contact of the entire periphery of the glass panel with the second support, wherein during said maintaining the glass panel continues to bend by sagging under gravity, giving said glass panel a third central sag more pronounced than the second central sag, the entire periphery of the glass panel still being in contact with the second support; and then a fourth step that includes stopping the sagging of the glass panel by cooling the glass panel, giving the glass panel a desired final shape, wherein the first support comprises a first peripheral support that supports said glass panel during said first step at said periphery of said glass panel and the second support comprises a second peripheral support that supports said glass panel during said second step at said periphery of said glass panel, the second peripheral support having at least partially a concavity greater than that of the first peripheral support, wherein said second peripheral support is a skeleton support, and wherein the first support further comprises an internal support that contacts said glass panel during said first step at more than 5 cm from the periphery of the glass panel, and wherein said internal support no longer contacts said glass panel during said third step.