Mold and a method of hot-forming a thermoplastic lens
US6884369B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2001 |
| Grant date | Apr 26, 2005 |
| Priority date | — |
| Expiry date | Dec 22, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The mold comprises two dies mounted in a sheath to slide along the axis of the sheath and each presenting a forming face facing the other. The two dies and the sheath are provided with intrinsic heat transfer means.A parison or preform of said thermoplastic material is placed between the two dies and the assembly is enclosed in the sheath; the dies and the sheath are heated by their intrinsic heat transfer means up to a forming temperature;The dies are moved towards each other to shape the material by plastic deformation until a predetermined relative position is reached corresponding to the thickness desired for the lens; the dies and the sheath are cooled by their intrinsic heat transfer means down to an unmolding temperature; and the finished lens is extracted from the mold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.