US3022472A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable equalizer employing semiconductive element
Assignee: AT&T Inc
•
Filing: 1958-01-22
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Granted: 1962-02-20
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Expires: 1978-01-22
Abstract
No abstract record available.
Inventors
- 👤 Tanenbaum Morris
- 👤 Jr Robert L Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:25
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/40; H03; H03H; H03H1/00; H03H1/02; H10; H10D; H10D99/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2102138A
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US2143407A
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US2521507A
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US2502479A
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US2666814A
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US2586080A
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US2666873A
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US2870271A
Cited
US2936425A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-02-19 | 1965-08-21 | 1966-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-02-19 | 1969-08-21 | 1970-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-02-19 | 1973-08-21 | 1974-02-20 | $7700.00 | Window Closed / Lapsed |