Patent US2540589A successfully refreshed from Google Patents.
US2540589A
Expired / Lapsed
US
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Magnetic testing recording system for metallic bodies
Assignee: Shell Development Co
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Filing: 1950-07-03
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Granted: 1951-02-06
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Expires: 1970-07-03
Abstract
No abstract record available.
Inventors
- 👤 Marion V Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:09
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; G01N27/82; G01N27/90; G01N27/9046
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2365706A
Cited
US2067804A
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US1910418A
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US1992100A
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US1960350A
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US2038046A
Cited
US2104646A
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GB541942A
Cited
US2359894A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-05 | 1954-08-07 | 1955-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-05 | 1958-08-07 | 1959-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-05 | 1962-08-07 | 1963-02-06 | $7700.00 | Window Closed / Lapsed |