Patent US2881654A successfully refreshed from Google Patents.
US2881654A
Expired / Lapsed
US
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Biconical refractor
Assignee: Individual
•
Filing: 1955-10-24
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Granted: 1959-04-14
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Expires: 1975-10-24
Abstract
No abstract record available.
Inventors
- 👤 Dominic S Toffolo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:43
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/001; G02B3/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US270132A
Cited
GB190929282A
Cited
US1202223A
Cited
FR686268A
Cited
FR714972A
Cited
US2059033A
Cited
US2514492A
Cited
US2587972A
Cited
US2821107A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-13 | 1962-10-13 | 1963-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-13 | 1966-10-13 | 1967-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-13 | 1970-10-13 | 1971-04-14 | $7700.00 | Window Closed / Lapsed |