US2754368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone system
Assignee: AT&T Inc
•
Filing: 1952-05-03
•
Granted: 1956-07-10
•
Expires: 1972-05-03
Abstract
No abstract record available.
Inventors
- 👤 Kermit S Dunlap
- 👤 Enoch B Ferrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:19
CPC Classifications
H; H04; H04Q; H04Q5/00; H04Q5/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2431692A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-07-10 | 1960-01-09 | 1960-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-07-10 | 1964-01-09 | 1964-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-07-10 | 1968-01-09 | 1968-07-10 | $7700.00 | Window Closed / Lapsed |