US2224677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signaling system
Assignee: AT&T Inc
•
Filing: 1939-03-23
•
Granted: 1940-12-10
•
Expires: 1959-03-23
Abstract
No abstract record available.
Inventors
- 👤 Clarence D Hanscom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:06
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/52; H04Q3/525
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 |