US2500680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining magnetic properties of well cores
Assignee: California Research LLC
•
Filing: 1947-12-06
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Granted: 1950-03-14
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Expires: 1967-12-06
Abstract
No abstract record available.
Inventors
- 👤 Henry N Herrick
- 👤 William M Schaufelberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:44
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/12; E; E21; E21B; E21B47/00; E21B47/02; E21B47/026; G01V; G01V3/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1792639A
Cited
USRE18555E
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US1916352A
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DE644858C
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US2150922A
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US2211158A
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US2359894A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-03-13 | 1953-09-12 | 1954-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-03-13 | 1957-09-12 | 1958-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-03-13 | 1961-09-12 | 1962-03-14 | $7700.00 | Window Closed / Lapsed |