US2381871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Communication system
Assignee: AT&T Inc
•
Filing: 1941-03-15
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Granted: 1945-08-14
•
Expires: 1961-03-15
Abstract
No abstract record available.
Inventors
- 👤 Walter M Bacon
- 👤 Fullerton S Kinkead
- 👤 Joseph A Krecek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:02
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/54
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) | 1948-08-13 | 1949-02-12 | 1949-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1952-08-13 | 1953-02-12 | 1953-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1956-08-13 | 1957-02-12 | 1957-08-14 | $7700.00 | Window Closed / Lapsed |