US2418406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective signaling system
Assignee: AT&T Inc
•
Filing: 1943-08-12
•
Granted: 1947-04-01
•
Expires: 1963-08-12
Abstract
No abstract record available.
Inventors
- 👤 Hanley Frank Harold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:18
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4902
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2168460A
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US2120971A
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US2321605A
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US2346251A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-03-31 | 1950-09-30 | 1951-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-03-31 | 1954-09-30 | 1955-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-03-31 | 1958-09-30 | 1959-04-01 | $7700.00 | Window Closed / Lapsed |