Patent US2397559A successfully refreshed from Google Patents.
US2397559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Facsimile signal inverter
Assignee: Western Union Telegraph Co
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Filing: 1942-05-16
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Granted: 1946-04-02
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Expires: 1962-05-16
Abstract
No abstract record available.
Inventors
- 👤 Frederic L O'brien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:28
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; H04N1/4072
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1949-04-01 | 1949-10-01 | 1950-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-04-01 | 1953-10-01 | 1954-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-04-01 | 1957-10-01 | 1958-04-02 | $7700.00 | Window Closed / Lapsed |