US2544330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective signaling device
Assignee: AT&T Inc
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Filing: 1947-11-04
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Granted: 1951-03-06
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Expires: 1967-11-04
Abstract
No abstract record available.
Inventors
- 👤 Jr Walter Koenig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:31
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)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-03-05 | 1954-09-04 | 1955-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-03-05 | 1958-09-04 | 1959-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-03-05 | 1962-09-04 | 1963-03-06 | $7700.00 | Window Closed / Lapsed |