US2224580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modulation system
Assignee: AT&T Inc
•
Filing: 1938-11-16
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Granted: 1940-12-10
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Expires: 1958-11-16
Abstract
No abstract record available.
Inventors
- 👤 Raymond O Wise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:08
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/34; H03F1/36; H03C; H03C3/00; H03C3/02; H03C3/04; H03D; H03D1/00; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26; H04J; H04J1/00; H04J1/02; H04J1/12
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) | 1943-12-10 | 1944-06-10 | 1944-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-12-10 | 1948-06-10 | 1948-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-12-10 | 1952-06-10 | 1952-12-10 | $7700.00 | Window Closed / Lapsed |