US2760005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone call originator
Assignee: AT&T Inc
•
Filing: 1955-03-07
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Granted: 1956-08-21
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Expires: 1975-03-07
Abstract
No abstract record available.
Inventors
- 👤 Fred N Williamson
- 👤 Edward C Zipf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:47
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/36; H04M3/362
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-08-21 | 1960-02-20 | 1960-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-08-21 | 1964-02-20 | 1964-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-08-21 | 1968-02-20 | 1968-08-21 | $7700.00 | Window Closed / Lapsed |