| 摘要 |
A sheet of toughened glass, as for a wind-screen, comprises peripheral regions 6 toughened to a first degree of toughening, demarcation zones 7 contiguous to the regions 6 and toughened to a lesser degree and, within the zones 7, an area comprising regions 8 of highly toughened glass alternating with regions 9 of lesser toughened glass. The sheet is toughened by chilling blast which are intercepted on each <PICT:1092651/C1/1> side to give the lesser toughened areas by a pair of bars (4) or a frame (4, 4a) with a series of spaced parallel members (5a), (5b) between the bars 4 or the top and bottom parts (4) of the frame. Wire gauze may be provided between the members (5a) or (5b). |
