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US2424971A
Expired / Lapsed
US
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Frequency-shift radio telegraph transmitting system
Assignee: AT&T Inc
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Filing: 1944-07-21
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Granted: 1947-08-05
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Expires: 1964-07-21
Abstract
No abstract record available.
Inventors
- 👤 James R Davey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:07
CPC Classifications
H; H03; H03C; H03C1/00; H03C1/52; H03C1/60; H04; H04L; H04L27/00; H04L27/10; H04L27/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1666206A
Cited
US1831516A
Cited
US1773116A
Cited
US1976393A
Cited
US1892383A
Cited
US2198248A
Cited
US2118917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-08-04 | 1951-02-03 | 1951-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-08-04 | 1955-02-03 | 1955-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-08-04 | 1959-02-03 | 1959-08-05 | $7700.00 | Window Closed / Lapsed |