US2577609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Call data recording automatic telephone system
Assignee: AT&T Inc
•
Filing: 1949-05-05
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Granted: 1951-12-04
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Expires: 1969-05-05
Abstract
No abstract record available.
Inventors
- 👤 Thomas L Dimond
- 👤 Charles A Wingardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:17
CPC Classifications
H; H04; H04M; H04M15/00; H04M15/08
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) | 1954-12-03 | 1955-06-04 | 1955-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-03 | 1959-06-04 | 1959-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-03 | 1963-06-04 | 1963-12-04 | $7700.00 | Window Closed / Lapsed |