Method for simplifying the casting of ophthalmic lenses
US6733701B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2001 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | May 15, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for casting an ophthalmic lens having a toric surface includes the step of providing a casting cell that includes a conventional front mold, a novel gasket, and a novel toric back mold. An annular carrier ring is integrally formed with or attached to the toric back mold. The gasket has a first annular flat step against which the front mold squarely abuts and a second annular flat step against which the annular carrier ring squarely abuts. The gasket includes no toric annular seat against which the front surface of a toric back mold abuts. This eliminates the need for a lens maker to maintain a large inventory of toric back molds and gaskets. The square seating enhances the sealing capability of the mold, reduces leaks, and produces lenses having fewer bubbles and flash on the edge of the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.