US2928039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant electromagnetic field well logging system
Assignee: Welex Inc
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Filing: 1956-10-05
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Granted: 1960-03-08
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Expires: 1976-10-05
Abstract
No abstract record available.
Inventors
- 👤 Jr Richard H Huddleston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:00
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/26; G01V3/28
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) | 1963-03-08 | 1963-09-07 | 1964-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-03-08 | 1967-09-07 | 1968-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-03-08 | 1971-09-07 | 1972-03-08 | $7700.00 | Window Closed / Lapsed |