Patent US3493847A successfully refreshed from Google Patents.
US3493847A
Expired / Lapsed
US
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On-load tap changing circuits
Assignee: English Electric Co Ltd
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Filing: 1966-12-01
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Granted: 1970-02-03
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Expires: 1986-12-01
Abstract
No abstract record available.
Inventors
- 👤 Vernon Rowley Hyde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:48
CPC Classifications
H; H01; H01F; H01F29/00; H01F29/02; H01F29/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2440983A
Cited
GB761983A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-02 | 1973-08-04 | 1974-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-02 | 1977-08-04 | 1978-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-02 | 1981-08-04 | 1982-02-03 | $7700.00 | Window Closed / Lapsed |