Patent US3225280A successfully refreshed from Google Patents.
US3225280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load protection circuits
Assignee: Singer Co
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Filing: 1963-08-12
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Granted: 1965-12-21
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Expires: 1983-08-12
Abstract
No abstract record available.
Inventors
- 👤 Happe Reynold
- 👤 Lawrence R Goetz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:50
CPC Classifications
H; H02; H02H; H02H5/00; H02H5/04; H02H5/042; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/292; H02P7/295
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
138 words
A COMBINED MOTOR PROTECTION AND SPEED CONTROL CIRCUIT COMPRISING A PAIR OF TERMINALS FOR CONNECTION TO AN A.C. VOLTAGE SOURCE, MOTOR WINDINGS, A FIRST CONTROLLED RECTIFIER, MEANS CONNECTING SAID MOTOR WINDINGS IN SERIES WITH THE ANODE-CATHODE CIRCUIT OF THE FIRST RECTIFIER AND SAID TERMINALS, ADJUSTABLE VOLTAGE-DIVIDER MEANS CONNECTED TO SAID TERMINALS FOR OBTAINING AN ADJUSTABLE VOLTAGE, A SECOND CONTROLLED RECTIFIER, MEANS INCLUDING THE ANODECATHODE CIRCUIT OF THE SECOND RECTIFIER FOR RENDERING THE ADJUSTABLE VOLTAGE EFFECTIVE TO SUPPLY ADJUSTABLE GATING SIGNALS TO THE GATE-CATHODE CIRCUIT OF THE FIRST RECTIFIER, MEANS COUPLED TO SAID TERMINALS FOR SUPPLYING A FIXED GATING SIGNAL TO THE SECOND RECTIFIER SUFFICIENT TO CAUSE IT NORMALLY TO FIRE, AND A THERMISTOR CONNECTED ELECTRICALLY IN SHUNT WITH THE GATE AND CATHODE OF THE SECOND RECTIFIER AND PHYSICALLY LOCATED IN GOOD HEAT TRANSFER RELATION WITH THE MOTOR WINDINGS.
Claim 2
Dependent Claim
138 words
A COMBINED MOTOR PROTECTION AND SPEED CONTROL CIRCUIT COMPRISING A PAIR OF TERMINALS FOR CONNECTION TO AN A.C. VOLTAGE SOURCE, MOTOR WINDINGS, A FIRST CONTROLLED RECTIFIER, MEANS CONNECTING SAID MOTOR WINDINGS IN SERIES WITH THE ANODE-CATHODE CIRCUIT OF THE FIRST RECTIFIER AND SAID TERMINALS, ADJUSTABLE VOLTAGE-DIVIDER MEANS CONNECTED TO SAID TERMINALS FOR OBTAINING AN ADJUSTABLE VOLTAGE, A SECOND CONTROLLED RECTIFIER, MEANS INCLUDING THE ANODECATHODE CIRCUIT OF THE SECOND RECTIFIER FOR RENDERING THE ADJUSTABLE VOLTAGE EFFECTIVE TO SUPPLY ADJUSTABLE GATING SIGNALS TO THE GATE-CATHODE CIRCUIT OF THE FIRST RECTIFIER, MEANS COUPLED TO SAID TERMINALS FOR SUPPLYING A FIXED GATING SIGNAL TO THE SECOND RECTIFIER SUFFICIENT TO CAUSE IT NORMALLY TO FIRE, AND A THERMISTOR CONNECTED ELECTRICALLY IN SHUNT WITH THE GATE AND CATHODE OF THE SECOND RECTIFIER AND PHYSICALLY LOCATED IN GOOD HEAT TRANSFER RELATION WITH THE MOTOR WINDINGS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-20 | 1969-06-21 | 1969-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-20 | 1973-06-21 | 1973-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-20 | 1977-06-21 | 1977-12-21 | $7700.00 | Window Closed / Lapsed |