Patent US2270638A successfully refreshed from Google Patents.
US2270638A
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Diode oscillator
Assignee: AT&T Inc
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Filing: 1940-02-17
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Granted: 1942-01-20
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Expires: 1960-02-17
Abstract
No abstract record available.
Inventors
- 👤 Frederick B Llewellyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:36
CPC Classifications
H; H01; H01J; H01J25/00; H01J25/74; H03; H03B; H03B9/00; H03B9/01
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) | 1945-01-19 | 1945-07-21 | 1946-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-01-19 | 1949-07-21 | 1950-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-01-19 | 1953-07-21 | 1954-01-20 | $7700.00 | Window Closed / Lapsed |