US2655631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting fluid movement in well bores
Assignee: California Research LLC
•
Filing: 1951-04-28
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Granted: 1953-10-13
•
Expires: 1971-04-28
Abstract
No abstract record available.
Inventors
- 👤 John E Walstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:31
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/10; E21B47/113
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1913293A
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US2184338A
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US2377501A
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US2475353A
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US2475354A
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US2517603A
Cited
US2550005A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-10-12 | 1957-04-13 | 1957-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-12 | 1961-04-13 | 1961-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-12 | 1965-04-13 | 1965-10-13 | $7700.00 | Window Closed / Lapsed |