Patent US2297931A successfully refreshed from Google Patents.
US2297931A
Expired / Lapsed
US
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Modulated high frequency transmitter
Assignee: EMI Ltd
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Filing: 1940-03-16
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Granted: 1942-10-06
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Expires: 1960-03-16
Abstract
No abstract record available.
Inventors
- 👤 White Eric Lawrence Casling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:18
CPC Classifications
H; H03; H03C; H03C1/00; H03C1/02; H03C1/06; H04; H04N; H04N5/00; H04N5/38; H04N5/40
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1945-10-05 | 1946-04-06 | 1946-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-10-05 | 1950-04-06 | 1950-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-10-05 | 1954-04-06 | 1954-10-06 | $7700.00 | Window Closed / Lapsed |