| 摘要 |
An apparatus for supporting sheets of material such as glass on a cushion of gas, comprises a plurality of supporting zones alternating with gas escape passages, each supporting zone having a blowing zone in the form of a slot and a multi-directional gas flow zone, the blowing slot and escape zone being arranged so that one surrounds the other. In one form, elements comprise hollow cylindrical member 1 within which are members having an upper cylindrical portion 2, and a lower conical portion 4 and cylindrical portion 5. The outer member 1 is fixed into and communicates with a plenum chamber 10, gas from which passes through openings 7, 8 in the member 1 into the annular slot 3 formed between members 1 and 2. The gas exhausts through passages 12. In another embodiment the support bed comprises a multiplicity of groups of elements fixed to a sole plate 30, e.g. of fused silica, the individual elements being attached to a cylindrical member 21 which contains a hemispherical cavity 22. Gas passes from a plenum chamber 31 into <PICT:1076872/C1/1> <PICT:1076872/C1/2> the cavity 22 and thence through passages 27 to the individual slots 26 of the elements, exhausting through passages 35. In a further form the exhaust passages are at the centre of the elements. The gas may be heated to heat a glass sheet 11 supported thereon or may be cold for tempering purposes. The support bed may be horizontal or slightly inclined and may include means for moving the sheet over the bed. If desired, the bed may have a predetermined curvature or be made to change its curvature along its length so as to heat bent sheets or cause flat sheets to be bent. |
