Patent US2640393A successfully refreshed from Google Patents.
US2640393A
Expired / Lapsed
US
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Reflecting optical objective
Assignee: Taylor Taylor and Hobson Ltd
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Filing: 1952-03-07
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Granted: 1953-06-02
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Expires: 1972-03-07
Abstract
No abstract record available.
Inventors
- 👤 Wreathall William Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:42
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/08; G02B17/0856; G02B17/086; G02B17/0804; G02B17/0808; G02B17/0884
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2141884A
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US2336379A
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US2350112A
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US2380887A
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US2378301A
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US2477331A
Cited
US2403660A
Cited
US2571743A
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 |