US2554778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency changer
Assignee: LENKURT ELECTRIC CO Inc
•
Filing: 1949-06-24
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Granted: 1951-05-29
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Expires: 1969-06-24
Abstract
No abstract record available.
Inventors
- 👤 Lennart G Erickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:33
CPC Classifications
H; H03; H03C; H03C1/00; H03C1/52; H03C1/54; H03C1/56; H03C1/58
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2144655A
Cited
US2462093A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-05-28 | 1954-11-27 | 1955-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-05-28 | 1958-11-27 | 1959-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-05-28 | 1962-11-27 | 1963-05-29 | $7700.00 | Window Closed / Lapsed |