Patent US4681763A successfully refreshed from Google Patents.
US2761922A
Expired / Lapsed
US
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Automatic transmission measuring circuit for successively testing the idle trunks in a group of trunks
Assignee: AT&T Inc
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Filing: 1955-06-20
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Granted: 1956-09-04
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Expires: 1975-06-20
Abstract
No abstract record available.
Inventors
- 👤 William R Carroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:38
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/32
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) | 1959-09-04 | 1960-03-05 | 1960-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-09-04 | 1964-03-05 | 1964-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-09-04 | 1968-03-05 | 1968-09-04 | $7700.00 | Window Closed / Lapsed |