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Patent US2725511A successfully refreshed from Google Patents.
US2725511A
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US
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Polyphase motor speed control
Assignee: Harnischfeger Corp
•
Filing: 1951-05-19
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Granted: 1955-11-29
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Expires: 1971-05-19
Abstract
No abstract record available.
Inventors
- 👤 Henry S Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:11
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/16; H02P25/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US808944A
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US1713223A
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US1844704A
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US1955322A
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US2228078A
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US2379146A
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US2411608A
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US2440319A
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US2384864A
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US2384865A
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US2676292A
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US2559538A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-11-28 | 1959-05-30 | 1959-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-11-28 | 1963-05-30 | 1963-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-11-28 | 1967-05-30 | 1967-11-29 | $7700.00 | Window Closed / Lapsed |