US2227438A
Expired / Lapsed
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Method of determining the petroleum oil content of earth samples
Assignee: RALPH H FASH
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Filing: 1938-09-24
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Granted: 1941-01-07
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Expires: 1958-09-24
Abstract
No abstract record available.
Inventors
- 👤 John G Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:08
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N33/00; G01N33/24; G01N33/241
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1944-01-07 | 1944-07-08 | 1945-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-01-07 | 1948-07-08 | 1949-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-01-07 | 1952-07-08 | 1953-01-07 | $7700.00 | Window Closed / Lapsed |