Process and plant for pressing flexible sheets
US4927479A · kind A · utility
Inventor
Key dates
| Filing date | Feb 28, 1989 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Feb 28, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T156/17
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The plant comprises a first vacuum plate with openings on which a sheet may be fixed in an exact planar way by suction. A second plate with a slightly arcuated surface and turned towards the first plate is adjustable in height by two compressing cylinders and is pivotingly fixed to the structure. The second plate is also a vacuum plate and may be unrolled on the first plate. During the unrolling motion, the second plate is conducted by means of retractable bolts which are engaged into corresponding openings of the first plate. To compress two sheets, a first sheet is fixed in an exact planar way to the first plate by suction and transferred by an unrolling motion of the second plate thereon, the suction force of the plate being reduced and that of the second plate being correspondingly increased. A second sheet is then fixed to the first plate and cold- or hot-compressed according to the same unrolling process as the first sheet. The plant is particularly appropriate for fabricating sheets or membrane keyboards.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.