Patent US2561722A successfully refreshed from Google Patents.
US2561722A
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US
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Signaling system
Assignee: AT&T Inc
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Filing: 1948-03-06
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Granted: 1951-07-24
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Expires: 1968-03-06
Abstract
No abstract record available.
Inventors
- 👤 Henry M Bascom
- 👤 Robert F Massonneau
- 👤 Jr Bernard Ostendorf
- 👤 Wilton T Rea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:21
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H03; H03K; H03K23/00; H03K23/82; H04L; H04L27/00; H04L27/18; H04L27/24
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) | 1954-07-23 | 1955-01-22 | 1955-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-07-23 | 1959-01-22 | 1959-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-07-23 | 1963-01-22 | 1963-07-24 | $7700.00 | Window Closed / Lapsed |