US2640299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of forming a multifocal lens
Assignee: American Optical Corp
•
Filing: 1949-12-07
•
Granted: 1953-06-02
•
Expires: 1969-12-07
Abstract
No abstract record available.
Inventors
- 👤 Samuel T Sheard
- 👤 Louis F Rowe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:34
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/20; C03B23/22; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1282877A
Cited
US1596397A
Cited
US1734428A
Cited
US1912165A
Cited
US1845940A
Cited
US1996442A
Cited
US2054351A
Cited
US2053377A
Cited
US1980401A
Cited
US2112659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |