US2575383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-frequency amplifying device
Assignee: AT&T Inc
•
Filing: 1946-10-22
•
Granted: 1951-11-20
•
Expires: 1966-10-22
Abstract
No abstract record available.
Inventors
- 👤 Lester M Field
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:15
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/16; H01J23/24; H01J23/30; H01J25/00; H01J25/34; H01J25/36; H01J25/38
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2064469A
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US2151992A
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US2266595A
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US2424576A
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US2413608A
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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) | 1954-11-19 | 1955-05-21 | 1955-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-19 | 1959-05-21 | 1959-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-19 | 1963-05-21 | 1963-11-20 | $7700.00 | Window Closed / Lapsed |