US2619528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective signaling system
Assignee: AT&T Inc
•
Filing: 1950-08-15
•
Granted: 1952-11-25
•
Expires: 1970-08-15
Abstract
No abstract record available.
Inventors
- 👤 Vroom Edward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:55
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/02; H04W88/022; H04W88/025; H04W88/028
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1498544A
Cited
US1814524A
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US2361766A
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US2405096A
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US2404106A
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US2503402A
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US2570279A
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US2563127A
Cited
US2564062A
Cited
US2568177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-11-25 | 1956-05-26 | 1956-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-11-25 | 1960-05-26 | 1960-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-11-25 | 1964-05-26 | 1964-11-25 | $7700.00 | Window Closed / Lapsed |