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Patent US2511615A successfully refreshed from Google Patents.
US2511615A
Expired / Lapsed
US
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Power line carrier frequency telephone system
Assignee: AT&T Inc
•
Filing: 1946-10-11
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Granted: 1950-06-13
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Expires: 1966-10-11
Abstract
No abstract record available.
Inventors
- 👤 John M Barstow
- 👤 Albert G Lang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:15
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/54; H04B2203/00; H04B2203/54; H04B2203/5429; H04B2203/5437; H04B2203/5462; H04B2203/5466
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1226389A
Cited
US1773613A
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US2294905A
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US2289048A
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US2383908A
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US2378326A
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US2440239A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-06-12 | 1953-12-12 | 1954-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-06-12 | 1957-12-12 | 1958-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-06-12 | 1961-12-12 | 1962-06-13 | $7700.00 | Window Closed / Lapsed |