Patent US1559920A successfully refreshed from Google Patents.
US1559920A
Expired / Lapsed
US
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Variable-speed induction motor
Assignee: NANCY J STEWART
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Filing: 1920-10-14
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Granted: 1925-11-03
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Expires: 1940-10-14
Abstract
No abstract record available.
Inventors
- 👤 Ralph E Stewart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:52
CPC Classifications
H; H02; H02K; H02K17/00; H02K17/02; H02K17/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1928-11-02 | 1929-05-04 | 1929-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1932-11-02 | 1933-05-04 | 1933-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1936-11-02 | 1937-05-04 | 1937-11-03 | $7700.00 | Window Closed / Lapsed |