Cushman, Darby & Cushman
Process and apparatus for vacuum forming
 A vacuum forming process, and an apparatus for carrying out the same, for imparting a predetermined shape to a sheet material. The process includes the steps of placing a thermally softened sheet material onto a molding surface of a mold and evacuating air remaining between the molding surface of the mold and the sheet material, thereby bringing the sheet material into a close contact with the molding surface of the surface of the mold. The vacuum forming process and apparatus is adapted for giving a predetermined shape to a sheet material having a low elongation ratio. In particular, when giving a predetermined shape to the sheet material, part of the sheet material is pressed with a pressing member against the molding surface of the mold, a peripheral portion of the sheet material is held with a holding member, and holding forces exerted by a plurality of holding portions of the holding member are varied in order to control movement amounts of the sheet material resulting from a pressing force of the pressing member. In this manner, a predetermined shape can be given to a sheet material without causing wrinkles thereto, even when the sheet material has a low elongation ratio. 
Toyoda Gosei Co., Ltd.
B B B B
B29C B29K B29C B29C
additional additional inventional inventional
Tetsuya Toru Akiyoshi Toshihiko
Fujii Kai Nagano Mori