US2697140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic testing system
Assignee: AT&T Inc
•
Filing: 1949-12-20
•
Granted: 1954-12-14
•
Expires: 1969-12-20
Abstract
No abstract record available.
Inventors
- 👤 Warren A Cornell
- 👤 Nathan I Hall
- 👤 Harold E Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:11
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/32; H04M3/323
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2457892A
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US2434989A
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US2400574A
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US2438492A
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US2414443A
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US2582691A
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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) | 1957-12-13 | 1958-06-14 | 1958-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-12-13 | 1962-06-14 | 1962-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-12-13 | 1966-06-14 | 1966-12-14 | $7700.00 | Window Closed / Lapsed |