US3750272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Machining contact lenses of flexible material
Assignee: EssilorLuxottica SA
•
Filing: 1971-01-18
•
Granted: 1973-08-07
•
Expires: 1991-01-18
Abstract
Abstract A method for machining contact lenses of flexible material such as silicone. The lens is centered on two rotary spindles of which one is a driving spindle and is clamped therebetween. An annular supporting member having a surface with the same curvature as the face of the lens maintains the shape of the flexible lens during rotation of the lens until it is hardened by the spraying of a jet of cooling fluid which may be liquid nitrogen or liquid air. The spraying of the lens continues while the diameter is reduced, if such reduction is necessary. The supporting member is then removed and the peripheral edge of the lens is machined.
Inventors
- 👤 G Gomond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:15
CPC Classifications
B; B24; B24B; B24B9/00; B24B9/02; B24B9/06; B24B9/08; B24B9/14; B24B9/142; B29; B29D; B29D11/00; B29D11/00932; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49995; Y10T29/49996
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
21 words
A method as claimed in claim 1, and reducing the diameter of the lens before the removal of the supporting member.
Claim 2
Independent Claim
78 words
A method for machining the peripheral edge of a flexible contact lens, comprising centering and clamping the lens between coaxial rotary spindles, supporting one face of the lens on an annular support surface of the same shape as the lens, setting at least one of the spindles in rotation for rotating the lens, cooling the lens until hard, moving the support surface away from the lens, and machining the peripheral edge of the lens while continuing the cooling.
Claim 3
Dependent Claim
26 words
A method as claimed in claim 1, in which the centering of said lens is effected by a sleeve slidably mounted on one of the spindles.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 4, in which the lens initially has a peripheral reinforcing shoulder for facilitating its centering.
Claim 5
Dependent Claim
34 words
A method as claimed in claim 1, in which said lens is centered by means of a focometer disposed on the axis of said rotating spindles, said spindles being axially bored for that purpose.
Claim 6
Dependent Claim
52 words
A method as claimed in claim 2, in which said centering of the lens with respect to its optical center is effected on a focometer, said reducing of the diameter of the lens being effected by punching out a central portion of the lens while the lens is disposed on said focometer.
Claim 7
Dependent Claim
58 words
A method as claimed in claim 2, in which the running-up to speed of said spindles is effected in two stages, first at reduced speed, lower than 1,000 r.p.m. for the complete cooling of the lens by said cooling fluid, and then at full speed, higher than 15,000 r.p.m. for reducing the diameter and machining of said lens.
Claim 8
Dependent Claim
23 words
A method as claimed in claim 1, in which said cooling fluid is a liquefied gas at a temperature lower than -100* C.
References Cited (Backward Citations)
US3030859A
Cited
US3078560A
Cited
US3160039A
Cited
US3145506A
Cited
US3301105A
Cited
US3423886A
Cited
US3528326A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |