Patent US2448772A successfully refreshed from Google Patents.
US2448772A
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Differential relay
Assignee: Cook Electric Co
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Filing: 1943-11-26
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Granted: 1948-09-07
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Expires: 1963-11-26
Abstract
No abstract record available.
Inventors
- 👤 Carl P Clare
- 👤 Weinreich George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:33
CPC Classifications
H; H01; H01H; H01H51/00; H01H51/02; H01H51/04; H01H51/12; H01H50/00; H01H50/16; H01H50/18; H01H50/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US724366A
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US1562646A
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US1559110A
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US1825238A
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US2096419A
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US2219157A
Cited
US2208225A
Cited
US2307077A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-09-07 | 1952-03-08 | 1952-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-09-07 | 1956-03-08 | 1956-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-09-07 | 1960-03-08 | 1960-09-07 | $7700.00 | Window Closed / Lapsed |