Patent US2921267A successfully refreshed from Google Patents.
US2921267A
Expired / Lapsed
US
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Protection against failure of pilot wave in carrier communication systems
Assignee: International Standard Electric Corp
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Filing: 1956-02-23
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Granted: 1960-01-12
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Expires: 1976-02-23
Abstract
No abstract record available.
Inventors
- 👤 Thomas David Lane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:51
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0082; H03F; H03F1/00; H03F1/34; H03F1/36; H03F3/00; H03F3/181; H03F3/26; H03F3/28; H03G3/00; H03G3/20; H03G3/22; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-11 | 1963-07-13 | 1964-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-11 | 1967-07-13 | 1968-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-11 | 1971-07-13 | 1972-01-12 | $7700.00 | Window Closed / Lapsed |