Patent US687209A successfully refreshed from Google Patents.
US2951982A
Expired / Lapsed
US
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Systems for electromagnetic investigation of media
Assignee: Schlumberger Well Surveying Corp
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Filing: 1955-07-22
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Granted: 1960-09-06
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Expires: 1975-07-22
Abstract
No abstract record available.
Inventors
- 👤 Nick A Schuster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:14
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/20; G01V3/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2735980A
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US1791933A
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US1803405A
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US2108463A
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US2669689A
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US2730673A
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US2712629A
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US2723374A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-09-06 | 1964-03-07 | 1964-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-09-06 | 1968-03-07 | 1968-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-09-06 | 1972-03-07 | 1972-09-06 | $7700.00 | Window Closed / Lapsed |