Patent US3249840A successfully refreshed from Google Patents.
US3249840A
Expired / Lapsed
US
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Speed control device responsive to counter e. m. f.
Assignee: Hagglund and Soner AB
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Filing: 1962-02-20
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Granted: 1966-05-03
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Expires: 1982-02-20
Abstract
No abstract record available.
Inventors
- 👤 Eriksson Erik Einar
- 👤 Tegstrom Johan Olof
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:28
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; H02P7/2913; H02P7/292; H02P7/293; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917; Y10S388/918
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
134 words
AN APPARATUS FOR ADJUSTING A MAGNITUDE TO BE CONTROLLED, FOR EXAMPLE THE SPEED OF A MOTOR COMPRISING A D.C. MOTOR ARMATURE, A CONTROLLED CURRENT VALVE, A FEED CURRENT SOURCE CONNECTED TO SAID CURRENT VALVE, A VOLTAGE COMPARISON DEVICE, SAID CURRENT VALVE HAVING A CONTROL ELECTRODE CONNECTD TO SAID ARMATURE, A GENERATOR FOR PULSATING CONTROL VOLTAGE, MEANS CONNECTING SAID CONTROL ELECTRODE OF THE CURRENT VALVE TO SAID GENERATOR AND SAID VOLTAGE COMPARISON DEVICE, AND SIGNAL TRANSMITTING MEANS CONNECTED WITH SAID ARMATURE AND SAID VOLTAGE COMPARISON DEVICE, THE GENERATOR BEING ADJUSTED TO BE OUT IN OPERATION BY A SIGNAL FROM THE VOLTAGE COMPARISON DEVICE, COMPRISING A DIODE, THE ARMATURE BEING CONNECTED IN PARALLEL WITH SAID DIODE TO ELIMINATE INDUCTION VOLTAGES WHICH HAVE REVERSED POLARITY AND WHICH ARISE WHEN THE CURRENT IS BROKEN BY THE CONTROL VALVE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-05-02 | 1969-11-01 | 1970-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-05-02 | 1973-11-01 | 1974-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-05-02 | 1977-11-01 | 1978-05-03 | $7700.00 | Window Closed / Lapsed |