US2631249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current transformer
Assignee: Individual
•
Filing: 1951-05-17
•
Granted: 1953-03-10
•
Expires: 1971-05-17
Abstract
No abstract record available.
Inventors
- 👤 Burton F B Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:59
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/02; H02M3/16; H02M3/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-03-09 | 1956-09-08 | 1957-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-03-09 | 1960-09-08 | 1961-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-03-09 | 1964-09-08 | 1965-03-10 | $7700.00 | Window Closed / Lapsed |