US4091057A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for injection molding lenses
Assignee: Aotec Inc
•
Filing: 1976-09-01
•
Granted: 1978-05-23
•
Expires: 1996-09-01
Abstract
Abstract A method and apparatus for injection molding thermoplastic lenses, such as prescription eyeglass lenses, in a single injection molding operation into a finished single vision or multifocal blank which does not require additional molding or polishing. Movable optical inserts (dies) are forced apart by injected polycarbonate, then the inserts are urged together forcing a portion of the injected polycarbonate into a pocket.
Inventors
- 👤 Hermann P. Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:44
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/00009; B29C; B29C45/00; B29C45/17; B29C45/26; B29C45/2669; B29C45/46; B29C45/56; B29C45/561; B29C2045/563; B29L; B29L2011/00; B29L2011/0016; Y; Y10; Y10S; Y10S425/00; Y10S425/808
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
155 words
A method for forming a thermoplastic optical lens blank in an injection molding apparatus where said apparatus includes an optical cavity for defining said optical lens blank comprising the steps of: injection molten plastic into said cavity at a first aperture along the edge of said cavity when said cavity has a volume greater than said optical lens said greater volume to assure better flow into the thinner section of said cavity; and compressing said cavity such that the thickness of said cavity is decreased so as to define said optical lens blank, thereby causing an flow of molten plastic from said optical cavity at a second aperture along said edge of said cavity, said second aperture spaced-apart from said first aperture; whereby said injected molten plastic flows into a cavity having a greater thickness than the thickness of said optical lens blank, thereby avoiding problems associated with conventional plastic flow into a thin cavity.
Claim 2
Independent Claim
155 words
A method for forming a thermoplastic optical lens blank in an injection molding apparatus where said apparatus includes an optical cavity for defining said optical lens blank comprising the steps of: injection molten plastic into said cavity at a first aperture along the edge of said cavity when said cavity has a volume greater than said optical lens said greater volume to assure better flow into the thinner section of said cavity; and compressing said cavity such that the thickness of said cavity is decreased so as to define said optical lens blank, thereby causing an flow of molten plastic from said optical cavity at a second aperture along said edge of said cavity, said second aperture spaced-apart from said first aperture; whereby said injected molten plastic flows into a cavity having a greater thickness than the thickness of said optical lens blank, thereby avoiding problems associated with conventional plastic flow into a thin cavity.
Claim 3
Dependent Claim
28 words
The method defined by claim 1 including the step of curing said lens blanking in said cavity after said flow of molten plastic from said cavity has ceased.
Claim 4
Dependent Claim
24 words
The method defined by claim 2 wherein pressure is applied to said blank during said curing so as to correct for shrinkage during curing.
Claim 5
Dependent Claim
12 words
The method defined by claim 3 wherein said molten plastic comprises polycarbonate.
Claim 6
Dependent Claim
21 words
The method defined by claim 4 wherein said cavity is heated prior to said injecting of molten polycarbonate into said cavity.
Claim 7
Independent Claim
129 words
A method for forming a thermoplastic optical lens in a cavity comprising the steps of: injection molten plastic into said cavity at a first aperture along the edge of said cavity when said cavity has a volume greater than said optical lens, said greater volume of said cavity obtained by the force of said injected molten plastic acting upon the surfaces defining said cavity during said injection of said molten plastic; applying first pressure to said injected molten plastic in said cavity so as to urge molten plastic to flow from said cavity through a second aperture along said edge of said cavity, said second aperture spaced-apart from said first aperture; applying second pressure to said molten plastic as said molten plastic cures; whereby an optical lens is formed.
Claim 8
Independent Claim
129 words
A method for forming a thermoplastic optical lens in a cavity comprising the steps of: injection molten plastic into said cavity at a first aperture along the edge of said cavity when said cavity has a volume greater than said optical lens, said greater volume of said cavity obtained by the force of said injected molten plastic acting upon the surfaces defining said cavity during said injection of said molten plastic; applying first pressure to said injected molten plastic in said cavity so as to urge molten plastic to flow from said cavity through a second aperture along said edge of said cavity, said second aperture spaced-apart from said first aperture; applying second pressure to said molten plastic as said molten plastic cures; whereby an optical lens is formed.
Claim 9
Dependent Claim
36 words
The method of claim 6 wherein said first pressure decreases the thickness of said cavity thereby urging said molten plastic from said cavity, said first pressure being applied until said cavity substantially defines said optical lens.
Claim 10
Dependent Claim
14 words
The method defined by claim 6 wherein said molten plastic comprises a molten polycarbonate.
References Cited (Backward Citations)
CA597171A
Cited
US2233057A
Cited
US2333131A
Cited
US2516373A
Cited
US3240854A
Cited
US3902693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |