Patent US4070642A successfully refreshed from Google Patents.
US2453243A
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Frequency modulating and harmonic producer apparatus
Assignee: AT&T Inc
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Filing: 1943-10-21
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Granted: 1948-11-09
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Expires: 1963-10-21
Abstract
No abstract record available.
Inventors
- 👤 Warren P Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:34
CPC Classifications
H; H03; H03F; H03F11/00; H03C; H03C3/00; H03C3/10; H03C7/00; H03C7/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1894687A
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US2071564A
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US2182377A
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US2191315A
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US2188154A
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US2230649A
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US2256931A
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US2306555A
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US2298085A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-11-09 | 1952-05-10 | 1952-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-11-09 | 1956-05-10 | 1956-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-11-09 | 1960-05-10 | 1960-11-09 | $7700.00 | Window Closed / Lapsed |