US1971730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for changing direct electric current into alternating current
Assignee: Individual
•
Filing: 1931-12-29
•
Granted: 1934-08-28
•
Expires: 1951-12-29
Abstract
No abstract record available.
Inventors
- 👤 Albert M Proctor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:55
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/20; H02M1/22
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) | 1937-08-27 | 1938-02-26 | 1938-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-08-27 | 1942-02-26 | 1942-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-08-27 | 1946-02-26 | 1946-08-28 | $7700.00 | Window Closed / Lapsed |