US2503371A
Expired / Lapsed
US
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Selective signaling system
Assignee: AT&T Inc
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Filing: 1949-02-21
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Granted: 1950-04-11
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Expires: 1969-02-21
Abstract
No abstract record available.
Inventors
- 👤 Albert E Bachelet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:08
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-04-10 | 1953-10-10 | 1954-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-04-10 | 1957-10-10 | 1958-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-04-10 | 1961-10-10 | 1962-04-11 | $7700.00 | Window Closed / Lapsed |