US2719289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical conversion system with high and low voltage alarm
Assignee: AT&T Inc
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Filing: 1952-05-16
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Granted: 1955-09-27
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Expires: 1972-05-16
Abstract
No abstract record available.
Inventors
- 👤 Jr John M Barstow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:09
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/10
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) | 1958-09-26 | 1959-03-28 | 1959-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-09-26 | 1963-03-28 | 1963-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-09-26 | 1967-03-28 | 1967-09-27 | $7700.00 | Window Closed / Lapsed |