US3867235A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical viewpoint
Assignee: Camelot Industries Corp
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Filing: 1972-11-02
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Granted: 1975-02-18
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Expires: 1992-11-02
Abstract
Abstract Optical viewports are disclosed which comprise an optically clear, relatively brittle, layer, such as glass, and an optically clear, flexible, tough polymeric film weakly bonded to the back of the brittle layer. A sharp impact force on the surface of the brittle layer results in fragmentation of that layer and partial delamination of the polymeric film from the surface of the brittle layer. The delamination results in improved dissipation of the impact energy, and the tough polymeric film retains its structural integrity thereby preventing fragments of the brittle layer from being projected rearwardly. Such an optical viewport can be used as an opthalmic safety lens to prevent injuries to the wearers eye upon receipt of an impact force on the lens.
Inventors
- 👤 Hollis E French
- 👤 Stanley C Herbine
- 👤 Gerald L Mcleod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:47
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/0073; B32; B32B; B32B17/00; B32B17/06; B32B17/10; B32B17/10005; B32B17/10009; B32B17/10018; B32B17/10036; B32B27/00; G; G02; G02B; G02B1/00; G02B1/10; G02B1/14; B32B2250/00; B32B2250/03; B32B2327/00; B32B2327/06; B32B2367/00; B32B2369/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31616; Y10T428/31634; Y10T428/31638
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
AN OPTICAL VIEWPOINT CONSISTING ESSENTIALLY OF AN OPTICALLY CLEAR, RELATIVELY BRITTLE, GLASS LAYER WHICH IS SUSCEPTIBLE TO FRAGMENTATION UPON THE RECEIPT OF A SUBSTANTIALY IMPACT FORCE AT ITS OUTER SURFACE AND AN OPTICALLY CLEAR, FLEXIBLE, TOUGH POLYMERIC FILM SUFFICIENT TO PREVENT REWARD PROJECTION OF GLASS FRAGMENTS UPON FRAGMENTATION OF SAID BRITTLE LAYER, SAID FILM BEING BONDED TO THE INNER SURFACE OF SAID BRITTLE LAYER BY A BOND WEAK ENOUGH TO CAUSE PARTIAL DELAMINATION OF THE FILM FROM THE BRITTLE LAYER WHEN SAID BRITTLE LAYR RECIEVES AN IMPACT FORCE SUFFICIENT TO CAUSE FRAGEMEMTATION THEREOF, SUCH DELAMINATION HELPING TO DISSIPATE IMPACT FORCE.
Claim 2
Dependent Claim
100 words
AN OPTICAL VIEWPOINT CONSISTING ESSENTIALLY OF AN OPTICALLY CLEAR, RELATIVELY BRITTLE, GLASS LAYER WHICH IS SUSCEPTIBLE TO FRAGMENTATION UPON THE RECEIPT OF A SUBSTANTIALY IMPACT FORCE AT ITS OUTER SURFACE AND AN OPTICALLY CLEAR, FLEXIBLE, TOUGH POLYMERIC FILM SUFFICIENT TO PREVENT REWARD PROJECTION OF GLASS FRAGMENTS UPON FRAGMENTATION OF SAID BRITTLE LAYER, SAID FILM BEING BONDED TO THE INNER SURFACE OF SAID BRITTLE LAYER BY A BOND WEAK ENOUGH TO CAUSE PARTIAL DELAMINATION OF THE FILM FROM THE BRITTLE LAYER WHEN SAID BRITTLE LAYR RECIEVES AN IMPACT FORCE SUFFICIENT TO CAUSE FRAGEMEMTATION THEREOF, SUCH DELAMINATION HELPING TO DISSIPATE IMPACT FORCE.
Claim 3
Dependent Claim
16 words
A viewport of claim 1 wherein the weak bond is formed by an intermediate bonding layer.
Claim 4
Dependent Claim
35 words
A viewport of claim 1 wherein said polymeric film is selected from group consisting of a cellulose acetate, cellulose propionate, polyester, polyvinyl chloride or copolymer of polyvinyl chloride with vinylidene chloride, polycarbonate or polyphenylene ether.
Claim 5
Dependent Claim
21 words
A viewport of claim 1 wherein the weak bond has a peel strength of less than 1/4 pound per linear inch.
Claim 6
Dependent Claim
22 words
A viewport of claim 3 wherein said intermediate bonding layer is selected from group consisting of polyvinyl acetate, polyvinyl butyrate or polystyrene.
Claim 7
Dependent Claim
36 words
A viewport of claim 4 wherein said polymeric film is selected from group consisting of a cellulose acetate, cellulose propionate, polyester, polyvinyl chloride or a copolymer of polyvinyl chloride with vinylidene chloride, polycarbonate or polyphenylene ether.
Claim 8
Dependent Claim
23 words
A viewport of claim 6 wherein said intermediate bonding layer is selected from group consisting of a polyvinyl acetate, polyvinyl butyrate or polystyrene.
Claim 9
Dependent Claim
19 words
A viewport of claim 2 wherein said bond has a peel strength below about 0.1 pounds per linear inch.
Claim 10
Dependent Claim
14 words
A viewport of claim 8 wherein said plastic film is formed from polyethylene terephthalate.
Claim 11
Dependent Claim
12 words
A viewport of claim 9 wherein said bonding layer is polyvinyl acetate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |