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Patent US2481381A successfully refreshed from Google Patents.
US2481381A
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Optical projection viewer for machine tools
Assignee: CLEVELAND GRINDING MACHINE Co
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Filing: 1946-04-25
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Granted: 1949-09-06
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Expires: 1966-04-25
Abstract
No abstract record available.
Inventors
- 👤 Banko George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:26
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1433877A
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US1687946A
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US2035780A
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US2197308A
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US2109849A
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US2155248A
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US2192529A
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US2221154A
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US2261772A
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US2372470A
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US2360772A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-09-05 | 1953-03-07 | 1953-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-09-05 | 1957-03-07 | 1957-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-09-05 | 1961-03-07 | 1961-09-06 | $7700.00 | Window Closed / Lapsed |