Patent US3539893A successfully refreshed from Google Patents.
US3539893A
Expired / Lapsed
US
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Hybrid motor control circuit for providing improved speed regulation
Assignee: International Business Machines Corp
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Filing: 1967-12-12
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Granted: 1970-11-10
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Expires: 1987-12-12
Abstract
No abstract record available.
Inventors
- 👤 Peter P Tong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:38
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; H02P7/2913; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3358206A
Cited
US3436635A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |