US2258303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for converting direct current into periodic varying current
Assignee: Individual
•
Filing: 1938-07-20
•
Granted: 1941-10-07
•
Expires: 1958-07-20
Abstract
No abstract record available.
Inventors
- 👤 Schmidt Karl Hermann
- 👤 Widakowich Marius
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:19
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/54; H02M7/58; H02M7/62
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) | 1944-10-06 | 1945-04-07 | 1945-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-10-06 | 1949-04-07 | 1949-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-10-06 | 1953-04-07 | 1953-10-07 | $7700.00 | Window Closed / Lapsed |