US2544871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-phase transformer
Assignee: McGraw Electric Co
•
Filing: 1947-04-24
•
Granted: 1951-03-13
•
Expires: 1967-04-24
Abstract
No abstract record available.
Inventors
- 👤 David E Wiegand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:29
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/24; H01F27/25; H01F41/00; H01F41/02; H01F41/0206; H01F41/0213; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49071; Y10T29/49075; Y10T29/49078
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US523572A
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US1390050A
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US1766654A
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US1780110A
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US2220732A
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US2408212A
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US2401952A
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US2355169A
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US2458112A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-03-12 | 1954-09-11 | 1955-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-03-12 | 1958-09-11 | 1959-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-03-12 | 1962-09-11 | 1963-03-13 | $7700.00 | Window Closed / Lapsed |