US3281633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lowering speed control for a.-g. hoist
Assignee: ABB Inc USA
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Filing: 1963-07-05
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Granted: 1966-10-25
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Expires: 1983-07-05
Abstract
No abstract record available.
Inventors
- 👤 Jensen Otto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:12
CPC Classifications
B; B66; B66C; B66C13/00; B66C13/18; B66C13/22; B66C13/23; B66C13/26; B66C2700/00; B66C2700/08; B66C2700/081
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
167 words
IN AN A.-C. HOIST COMPRISING AN A.-C. MOTOR HAVING A STATOR ENERGIZABLE FROM AN A.-C. SOURCE, A ROTOR, AND A D.-C. CURRENT INJECTION CIRCUIT INDEPENDENT OF SAID A.-C. SOURCE FOR INJECTING D.-C. CURRENT INTO SAID STATOR DURING LOWERING OPERATION SIMULTANEOUSLY WITH THE APPLICATION OF LOWERING A.-C. POWER TO SAID STATOR; SAID D.-C. CURRENT INJECTION CIRCUIT INCLUDING AN AMPLIFIER MEANS, A FIRST ADJUSTABLE CONSTANT D.-C. VOLTAGE SOURCE, AND A SECOND D.-C. SOURCE HAVING A VOLTAGE OUTPUT RESPONSIVE TO THE SPEED OF SAID ROTOR; SAID AMPLIFIER MEANS HAVING AN OUTPUT CIRCUIT FOR INJECTING SAID D.-C. CURRENT INTO SAID STATOR AND AN INPUT CIRCUIT FOR CONTROLLING THE CURRENT MAGNITUDE OF SAID OUTPUT CIRCUIT; SAID INPUT CIRCUIT BEING CONNECTED IN SERIES WITH SAID FIRST AND SECOND D.-C. SOURCES WITH THE POLARITIES OF SAID FIRST AND SECOND D.-C. SOURCES OPPOSING ONE ANOTHER; SAID SPEED OF SAID ROTOR BEING CHANGED BY INJECTED D.-C. CURRENT IN SAID STATOR IN A DIRECTION TO DECREASE THE OUTPUT VOLTAGE DIFFERENCE BETWEEN SAID FIRST AND SECOND D.-C. SOURCES.
Claim 2
Dependent Claim
167 words
IN AN A.-C. HOIST COMPRISING AN A.-C. MOTOR HAVING A STATOR ENERGIZABLE FROM AN A.-C. SOURCE, A ROTOR, AND A D.-C. CURRENT INJECTION CIRCUIT INDEPENDENT OF SAID A.-C. SOURCE FOR INJECTING D.-C. CURRENT INTO SAID STATOR DURING LOWERING OPERATION SIMULTANEOUSLY WITH THE APPLICATION OF LOWERING A.-C. POWER TO SAID STATOR; SAID D.-C. CURRENT INJECTION CIRCUIT INCLUDING AN AMPLIFIER MEANS, A FIRST ADJUSTABLE CONSTANT D.-C. VOLTAGE SOURCE, AND A SECOND D.-C. SOURCE HAVING A VOLTAGE OUTPUT RESPONSIVE TO THE SPEED OF SAID ROTOR; SAID AMPLIFIER MEANS HAVING AN OUTPUT CIRCUIT FOR INJECTING SAID D.-C. CURRENT INTO SAID STATOR AND AN INPUT CIRCUIT FOR CONTROLLING THE CURRENT MAGNITUDE OF SAID OUTPUT CIRCUIT; SAID INPUT CIRCUIT BEING CONNECTED IN SERIES WITH SAID FIRST AND SECOND D.-C. SOURCES WITH THE POLARITIES OF SAID FIRST AND SECOND D.-C. SOURCES OPPOSING ONE ANOTHER; SAID SPEED OF SAID ROTOR BEING CHANGED BY INJECTED D.-C. CURRENT IN SAID STATOR IN A DIRECTION TO DECREASE THE OUTPUT VOLTAGE DIFFERENCE BETWEEN SAID FIRST AND SECOND D.-C. SOURCES.
References Cited (Backward Citations)
US2919391A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-10-24 | 1970-04-25 | 1970-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-10-24 | 1974-04-25 | 1974-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-10-24 | 1978-04-25 | 1978-10-25 | $7700.00 | Window Closed / Lapsed |