Patent US2688658A successfully refreshed from Google Patents.
US2688658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Call data recording telephone system
Assignee: AT&T Inc
•
Filing: 1947-07-07
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Granted: 1954-09-07
•
Expires: 1967-07-07
Abstract
No abstract record available.
Inventors
- 👤 Warren W Carpenter
- 👤 Raymond E Collis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:47
CPC Classifications
H; H04; H04M; H04M15/00; H04M15/04
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-09-06 | 1958-03-08 | 1958-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-09-06 | 1962-03-08 | 1962-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-09-06 | 1966-03-08 | 1966-09-07 | $7700.00 | Window Closed / Lapsed |