Process and apparatus for vacuum forming
US5128090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1990 |
| Grant date | Jul 7, 1992 |
| Priority date | — |
| Expiry date | Dec 10, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2995/0077
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.