US2541120A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable speed electric motor
Assignee: BIRTMAN ELECTRIC Co
•
Filing: 1946-10-31
•
Granted: 1951-02-13
•
Expires: 1966-10-31
Abstract
No abstract record available.
Inventors
- 👤 Sparklin Charles Harold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:43
CPC Classifications
H; H02; H02K; H02K11/00; H02K11/20; H02K11/21; H02K11/23
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1434640A
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US1965669A
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US2099050A
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US2103589A
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US2143921A
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US2188559A
Cited
US2187272A
Cited
US2241528A
Cited
US2381914A
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US2292567A
Cited
US2353314A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-12 | 1954-08-14 | 1955-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-12 | 1958-08-14 | 1959-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-12 | 1962-08-14 | 1963-02-13 | $7700.00 | Window Closed / Lapsed |