Spectacle frame having snap-in lenses
US4196982A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 1978 |
| Grant date | Apr 8, 1980 |
| Priority date | — |
| Expiry date | Mar 23, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C1/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A plastic frame safety spectacle of the type provided with removeable concavo-convex lenses has a variable-depth lens channel formed in the respective plastic rims, each channel being configured to complementally receive a lens periphery whereby the lenses are securely held in position within the rims yet may be removed or replaced using only manual pressure and without requiring heating or other special processing of the frame. Each lens channel is continuous around its respective rim, gradually and progressively becoming deeper as the upper portion of the rim is approached such that maximum restraining is provided for the lenses along the top rims where deformation is most likely to occur from twisting or bending of the spectacle frame. The back portion of each rim is provided with a lens-engaging support ledge to preclude removal of the lenses from the backside of the frame thereby seating the lenses against dislodging by frontal impact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.