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Patent US2575993A successfully refreshed from Google Patents.
US2575993A
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US
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Multiple carrier transmission system
Assignee: AT&T Inc
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Filing: 1948-11-27
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Granted: 1951-11-20
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Expires: 1968-11-27
Abstract
No abstract record available.
Inventors
- 👤 William R Bennett
- 👤 Carl B H Feldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:32
CPC Classifications
H; H03; H03B; H03B19/00; H03B19/06; H03B19/08; H03B19/12; H04; H04J; H04J1/00; H04J1/02; H04J1/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1956397A
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US2144380A
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US2188500A
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US2287925A
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US2371988A
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GB556079A
Cited
US2433343A
Cited
US2408692A
Cited
US2445618A
Cited
US2444928A
Cited
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 |