US2440480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical insulation testing apparatus
Assignee: AT&T Inc
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Filing: 1944-03-31
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Granted: 1948-04-27
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Expires: 1964-03-31
Abstract
No abstract record available.
Inventors
- 👤 Clay E Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:50
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/50; G01R31/58
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) | 1951-04-27 | 1951-10-27 | 1952-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-27 | 1955-10-27 | 1956-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-27 | 1959-10-27 | 1960-04-27 | $7700.00 | Window Closed / Lapsed |