Patent US2497859A successfully refreshed from Google Patents.
US2497859A
Expired / Lapsed
US
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Frequency diversity telegraph system
Assignee: Western Union Telegraph Co
•
Filing: 1947-11-19
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Granted: 1950-02-21
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Expires: 1967-11-19
Abstract
No abstract record available.
Inventors
- 👤 John E Boughtwood
- 👤 Alfred E Michon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:36
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/02; H04L1/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1875165A
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US2070418A
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US2154921A
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US2253832A
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US2282526A
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US2253867A
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US2309678A
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US2358448A
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US2373495A
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US2386844A
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US2420868A
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US2384456A
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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) | 1953-02-20 | 1953-08-22 | 1954-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-02-20 | 1957-08-22 | 1958-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-02-20 | 1961-08-22 | 1962-02-21 | $7700.00 | Window Closed / Lapsed |