Patent US3558285A successfully refreshed from Google Patents.
Patent US3553555A successfully refreshed from Google Patents.
US3553555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motor speed control apparatus, system and method
Assignee: Systron Donner Corp
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Filing: 1967-06-27
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Granted: 1971-01-05
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Expires: 1987-06-27
Abstract
Abstract SPEED CONTROL APPARATUS CONSISTING OF A MOTOR IN WHICH THE ROTOR ROTATES PRECISELY IN SYNCHRONISM WITH A PREDETERMINED OR COMMANDED FREQUENCY BY AUTOMATIC SYNCHRONIZATION OF SHAFT ROTATION THROUGH USE OF A DIGITAL PHASE-LOCKED SPEED CONTROL. A PULSE SIGNAL GENERATED BY THE MOTOR IS COMPARED WITH A REFERENCE PULSE SIGNAL TO PRODUCE AN ERROR SIGNAL WHICH CONTROLS POWER TO THE MOTOR. FOR STABILIZATION, THE ERROR SIGNAL MAY BE MODIFIED BY THE INTEGRAL OF AN ANGULAR ACCELERATION FEEDBACK SIGNAL.
Inventors
- 👤 Harold D Morris
- 👤 Philip G Leigh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:05
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04; H02P27/045; H02P23/00; H02P23/18; H02P23/186; H02P27/048; H02P27/06; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/292; H02P7/293; H02P27/047
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |