US1838280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric transformer
Assignee: Ferranti International PLC
•
Filing: 1928-07-06
•
Granted: 1931-12-29
•
Expires: 1948-07-06
Abstract
No abstract record available.
Inventors
- 👤 Norris Eric Douglas Tobias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:54
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/28; H01F27/2823
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) | 1934-12-28 | 1935-06-29 | 1935-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-12-28 | 1939-06-29 | 1939-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-12-28 | 1943-06-29 | 1943-12-29 | $7700.00 | Window Closed / Lapsed |