US2538829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiplex telegraph system using frequency discrimination
Assignee: RCA Corp
•
Filing: 1945-04-21
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Granted: 1951-01-23
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Expires: 1965-04-21
Abstract
No abstract record available.
Inventors
- 👤 Gilbert R Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:25
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/06; H04L5/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1661962A
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US1361522A
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FR708641A
Cited
US2276154A
Cited
US2313209A
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US2301373A
Cited
US2291369A
Cited
US2424243A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-01-22 | 1954-07-24 | 1955-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-01-22 | 1958-07-24 | 1959-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-01-22 | 1962-07-24 | 1963-01-23 | $7700.00 | Window Closed / Lapsed |