| 摘要 |
Apparatus operable in accordance with the method of the present invention is provided for selectively cooling areas of a glass sheet during heating in the lehr in order to eliminate hot spots and minimize undesirable sagging of portions of the glass sheet. The apparatus includes a gas hearth block upon which the glass sheet is supported during heating and an air nozzle or air nozzles connected to a source of compressed room temperature air located over those areas of the glass sheet that tend to develop hot spots. The air nozzle or air nozzles blow cooler air onto those selected areas of the glass sheet and even out the temperature of the heated glass sheet. This may be done prior to forming and/or tempering the glass sheet. The method and apparatus of the present invention is particularly useful with automobile glazings, such as sidelights and rear windows, bearing peripheral dark banding which show an increased tendency to sag during heating, particularly at the top edge portions.
|
