| 摘要 |
When sheets of glass or of another deformable material are shaped by a process which comprises the use of a partial vacuum support 50 in which the lower wall of sheet metal 54 comprises a series of openings 55 through which air is drawn by partial vacuum to seize a sheet and to shape it by partial vacuum, the series of openings must be greater than any dimension of the sheet to be shaped, with the result that at the time when the latter arrives at a shaping station in correctly aligned position to be seized by the partial vacuum support, there is a continuous line of openings outside each side of the sheet which is to be seized by partial vacuum. Otherwise, when the sheet is seized by suction, it is moved uncontrollably transversely and/or lengthwise, in the path which it covers in order to be applied against the perforated lower wall. <IMAGE>
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