Patent US2881535A successfully refreshed from Google Patents.
US2881535A
Expired / Lapsed
US
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Sonar signal simulator
Assignee: Individual
•
Filing: 1954-09-17
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Granted: 1959-04-14
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Expires: 1974-09-17
Abstract
No abstract record available.
Inventors
- 👤 Robert H Harwood
- 👤 Zack D Reynolds
- 👤 Earl G Hedger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:27
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/48; G06G7/78; G09; G09B; G09B9/00; G09B9/56
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2713729A
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US2524847A
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US2517591A
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US2529468A
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US2522541A
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US2548684A
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US2605556A
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US2445712A
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 |