| 摘要 |
1,119,191. Making hollow panels. OLIN MATHIESON CHEMICAL CORP. 22 Oct., 1965 [2 Nov., 1964], No. 44888/65. Heading B3A. [Also in Division B5] A blank, formed by a pair of superimposed sheets of which one sheet 8 is coated with patterns 12 and 13 of stopweld material, is rolled to selectively pressure weld the sheets together, fluid pressure is introduced into pattern 12 to expand the pattern and form a seal between the blank and a pair of supporting platens 24, 25, and the pattern 13 is then expanded. To control the expansion of the pattern 13 a relatively low fluid pressure is introduced into the space 26, the pressure causing the lower surface of the blank to remain flat after expansion of the pattern 13 or to distend outwards slightly. The pattern 12 is subsequently cut off and discarded. A constriction 15 between the two patterns is designed to open when the fluid pressure delivered at 10 reaches a predetermined value. Alternatively the patterns 12 and 13 can be provided with separate inlets (Fig. 4, not shown) extending to the edge 11 of the sheet 8, a rubber seal extending between the ends of the pattern 12. The two sheets may be of metal or plastics material, with one metal and one plastics sheet, if desired. |
