Patent US2892042A successfully refreshed from Google Patents.
US2784255A
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Keyed frequency modulation carrier wave systems
Assignee: International Standard Electric Corp
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Filing: 1951-11-29
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Granted: 1957-03-05
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Expires: 1971-11-29
Abstract
No abstract record available.
Inventors
- 👤 Earp Charles William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:28
CPC Classifications
H; H04; H04J; H04J3/00; G; G06; G06G; G06G7/00; G06G7/12; G06G7/18; G06G7/184; H03; H03K; H03K7/00; H03K7/04; H03K9/00; H03K9/04; H04J3/02; H04J3/04
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) | 1960-03-04 | 1960-09-03 | 1961-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-04 | 1964-09-03 | 1965-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-04 | 1968-09-03 | 1969-03-05 | $7700.00 | Window Closed / Lapsed |