US2939077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase discriminating system
Assignee: Shell USA Inc
•
Filing: 1954-09-27
•
Granted: 1960-05-31
•
Expires: 1974-09-27
Abstract
No abstract record available.
Inventors
- 👤 Jr Franklin H Branin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:24
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2627539A
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US1645618A
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US2200863A
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US2457727A
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US2337540A
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US2577668A
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US2525780A
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US2617858A
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US2693576A
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US2558190A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |