Patent US3308374A successfully refreshed from Google Patents.
US3308374A
Expired / Lapsed
US
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Tap changing apparatus for a transformer
Assignee: Toshiba Corp
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Filing: 1963-11-27
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Granted: 1967-03-07
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Expires: 1983-11-27
Abstract
No abstract record available.
Inventors
- 👤 Kagawa Masaaki
- 👤 Watanabe Akira
- 👤 Watanabe Junichi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:53
CPC Classifications
B; B60; B60L; B60L9/00; B60L9/02; B60L9/08; H; H01; H01F; H01F29/00; H01F29/02; H01F29/04; B60L2200/00; B60L2200/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
168 words
TAP CHANGING APPARATUS COMPRISING A COMBINATION OF AN ELECTRIC TRANSFORMER INCLUDING A WINDING PROVIDED WITH A PLURALITY OF VOLTAGE ADJUSTING TAPS AND CONNECTED TO BE ENERGIZED FROM A SOURCE OF ALTERNATING CURRENT, A LOAD SUPPLIED WITH A VARIABLE VOLTAGE FROM SAID TRANSFORMER, A PLURALITY OF FIRST CONTACTORS EACH ASSOCIATED WITH ONE OF SAID TAPS OF SAID TRANSFORMER WINDING TO CONNECT SAID ONE TAP TO SAID LOAD, A PAIR OF BRANCH CIRCUITS EACH INCLUDING A REACTOR WINDING AND A SECOND CONTACTOR FOR CONNECTING ALTERNATING ONES OF SAID FIRST CONTACTORS TO SAID LOAD, A THIRD CONTACTOR CONNECTED ACROSS TERMINALS OF SAID REACTOR WINDINGS WHICH ARE CLOSE TO SAID TRANSFORMER WINDING, SAID THIRD CONTACTOR BEING ARRANGED TO BE CLOSED WHEN ONE OF SAID TAPS IS SELECTED BUT OPENED DURING TAP CHANGING, A PAIR OF SEMICONDUCTOR SWITCHES CONNECTED IN REVERSE PARALLEL RELATION ACROSS THE OPPOSITE TERMINALS OF SAID REACTOR WINDINGS TO PASS POSITIVE AND NEGATIVE HALF CYCLES, RESPECTIVELY OF SAID ALTERNATING CURRENT WHEN SAID SECOND CONTACTORS ARE OPERATED DURING TAP CHANGING OPERATION.
Claim 2
Dependent Claim
168 words
TAP CHANGING APPARATUS COMPRISING A COMBINATION OF AN ELECTRIC TRANSFORMER INCLUDING A WINDING PROVIDED WITH A PLURALITY OF VOLTAGE ADJUSTING TAPS AND CONNECTED TO BE ENERGIZED FROM A SOURCE OF ALTERNATING CURRENT, A LOAD SUPPLIED WITH A VARIABLE VOLTAGE FROM SAID TRANSFORMER, A PLURALITY OF FIRST CONTACTORS EACH ASSOCIATED WITH ONE OF SAID TAPS OF SAID TRANSFORMER WINDING TO CONNECT SAID ONE TAP TO SAID LOAD, A PAIR OF BRANCH CIRCUITS EACH INCLUDING A REACTOR WINDING AND A SECOND CONTACTOR FOR CONNECTING ALTERNATING ONES OF SAID FIRST CONTACTORS TO SAID LOAD, A THIRD CONTACTOR CONNECTED ACROSS TERMINALS OF SAID REACTOR WINDINGS WHICH ARE CLOSE TO SAID TRANSFORMER WINDING, SAID THIRD CONTACTOR BEING ARRANGED TO BE CLOSED WHEN ONE OF SAID TAPS IS SELECTED BUT OPENED DURING TAP CHANGING, A PAIR OF SEMICONDUCTOR SWITCHES CONNECTED IN REVERSE PARALLEL RELATION ACROSS THE OPPOSITE TERMINALS OF SAID REACTOR WINDINGS TO PASS POSITIVE AND NEGATIVE HALF CYCLES, RESPECTIVELY OF SAID ALTERNATING CURRENT WHEN SAID SECOND CONTACTORS ARE OPERATED DURING TAP CHANGING OPERATION.
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) | 1970-03-06 | 1970-09-05 | 1971-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-03-06 | 1974-09-05 | 1975-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-03-06 | 1978-09-05 | 1979-03-07 | $7700.00 | Window Closed / Lapsed |