US2481932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Supervisory signaling in telephone systems
Assignee: AT&T Inc
•
Filing: 1946-12-27
•
Granted: 1949-09-13
•
Expires: 1966-12-27
Abstract
No abstract record available.
Inventors
- 👤 Lindley A Kille
- 👤 Theodore D Robb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:28
CPC Classifications
H; H04; H04Q; H04Q3/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1990437A
Cited
US2298751A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-09-12 | 1953-03-14 | 1953-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-09-12 | 1957-03-14 | 1957-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-09-12 | 1961-03-14 | 1961-09-13 | $7700.00 | Window Closed / Lapsed |