US2938426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractors
Assignee: American Optical Corp
•
Filing: 1956-12-31
•
Granted: 1960-05-31
•
Expires: 1976-12-31
Abstract
No abstract record available.
Inventors
- 👤 John T Armbruster
- 👤 John R Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:12
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/02; A61B3/028; A61B3/0285
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US427688A
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US767392A
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US1678479A
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US1937228A
Cited
US1945940A
Cited
US2036337A
Cited
US2117441A
Cited
US2470012A
Cited
US2329907A
Cited
US2707901A
Cited
US2843935A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |