US2673900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-frequency amplifying device
Assignee: AT&T Inc
•
Filing: 1946-10-23
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Granted: 1954-03-30
•
Expires: 1966-10-23
Abstract
No abstract record available.
Inventors
- 👤 William W Mumford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:37
CPC Classifications
B; B23; B23F; B23F5/00; B23F5/02; B23F5/06; H; H01; H01J; H01J23/00; H01J23/36; H01J23/40; H01J23/42; H01J23/48; H01J23/52
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2433074A
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US2442118A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-03-29 | 1957-09-28 | 1958-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-03-29 | 1961-09-28 | 1962-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-03-29 | 1965-09-28 | 1966-03-30 | $7700.00 | Window Closed / Lapsed |