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Patent US3520263A successfully refreshed from Google Patents.
US3520263A
Expired / Lapsed
US
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Constant depth buoyancy system
Assignee: United States Department of the Navy
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Filing: 1968-09-16
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Granted: 1970-07-14
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Expires: 1988-09-16
Abstract
No abstract record available.
Inventors
- 👤 Robert D Berry
- 👤 Jay Witcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:01
CPC Classifications
B; B63; B63G; B63G8/00; B63G8/14; B63G8/22; F; F42; F42B; F42B19/00; F42B19/01; F42B19/04; F42B22/00; F42B22/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |