Patent US2212839A successfully refreshed from Google Patents.
US2212839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency tuned circuits
Assignee: EMI Ltd
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Filing: 1938-07-02
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Granted: 1940-08-27
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Expires: 1958-07-02
Abstract
No abstract record available.
Inventors
- 👤 Lett Frederic Tom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:35
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/1638; H03; H03H; H03H7/00; H03H7/01; H03H7/0153; H03H7/0161; H03H7/17; H03H7/1741; H03H7/1775
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) | 1943-08-27 | 1944-02-26 | 1944-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-08-27 | 1948-02-26 | 1948-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-08-27 | 1952-02-26 | 1952-08-27 | $7700.00 | Window Closed / Lapsed |