Patent US2457278A successfully refreshed from Google Patents.
US2457278A
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Frequency responsive system
Assignee: Curtiss Wright Corp
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Filing: 1945-05-12
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Granted: 1948-12-28
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Expires: 1965-05-12
Abstract
No abstract record available.
Inventors
- 👤 Joseph R Schoenbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:27
CPC Classifications
H; H02; H02P; H02P23/00; H02P23/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US679175A
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US1663086A
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US1708544A
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US1787997A
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US1762725A
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US1856707A
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US2153470A
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US2197485A
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US2228090A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-12-28 | 1952-06-28 | 1952-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-28 | 1956-06-28 | 1956-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-28 | 1960-06-28 | 1960-12-28 | $7700.00 | Window Closed / Lapsed |