| 主权项 |
1. An apparatus for tempering glass sheets, which comprises a furnace heating glass sheets to a tempering temperature and including a conveyor track for glass sheets, and a quenching unit cooling glass sheets and including a conveyor track and cooling air enclosures set above and below the conveyor track and having cooling air blast openings in such a disposition that the cooling effect of a blast through the blast openings is directed to the top and bottom surfaces of a glass sheet across the entire width of the glass sheet moving in the quenching unit, wherein, in order to eliminate or reduce the bi-stability of a tempered, substantially flat glass sheet, at least one cooling air enclosure above the conveyor track includes a subarea of weakened cooling effect and at least one cooling air enclosure below the conveyor track includes a subarea of weakened cooling effect, said subareas having a weakened cooling effect as compared to the cooling effect of the cooling air enclosures outside the subareas over a surface area of the cooling air enclosures equivalent to the subareas, the subareas being located relative to the moving glass sheet in such a manner that the cooling effect generated by a blast occurring through the blast openings on both surfaces of the moving glass sheet is weaker on the glass sheet's middle lane than on both side lanes of the glass sheet. |
