Patent US2421018A successfully refreshed from Google Patents.
US2799818A
Expired / Lapsed
US
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Electrical control systems for adjusting and controlling the speed of a series wound electric motor
Assignee: Individual
•
Filing: 1953-05-01
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Granted: 1957-07-16
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Expires: 1973-05-01
Abstract
No abstract record available.
Inventors
- 👤 Walter J Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:31
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/30; H02P7/305
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) | 1960-07-15 | 1961-01-14 | 1961-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-15 | 1965-01-14 | 1965-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-15 | 1969-01-14 | 1969-07-16 | $7700.00 | Window Closed / Lapsed |