US2721898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone system
Assignee: Automatic Electric Laboratories Inc
•
Filing: 1953-10-07
•
Granted: 1955-10-25
•
Expires: 1973-10-07
Abstract
No abstract record available.
Inventors
- 👤 Clarence E Lomax
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:18
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0016
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1944269A
Cited
US2291496A
Cited
US2372353A
Cited
US2569650A
Cited
US2574454A
Cited
US2647163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-10-24 | 1959-04-25 | 1959-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-24 | 1963-04-25 | 1963-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-24 | 1967-04-25 | 1967-10-25 | $7700.00 | Window Closed / Lapsed |