US2428767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motor control circuits
Assignee: AT&T Inc
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Filing: 1943-09-15
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Granted: 1947-10-14
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Expires: 1963-09-15
Abstract
No abstract record available.
Inventors
- 👤 Walter P Albert
- 👤 Richard C Davis
- 👤 Robert H Gumley
- 👤 William H T Holden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:25
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/16
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) | 1950-10-13 | 1951-04-14 | 1951-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-10-13 | 1955-04-14 | 1955-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-10-13 | 1959-04-14 | 1959-10-14 | $7700.00 | Window Closed / Lapsed |