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Patent US2213294A successfully refreshed from Google Patents.
US2213294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential protection means
Assignee: Individual
•
Filing: 1938-12-24
•
Granted: 1940-09-03
•
Expires: 1958-12-24
Abstract
No abstract record available.
Inventors
- 👤 Robert I Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:26
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/28; H02H3/30; H02H3/307; H02H3/286
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) | 1943-09-03 | 1944-03-04 | 1944-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-09-03 | 1948-03-04 | 1948-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-09-03 | 1952-03-04 | 1952-09-03 | $7700.00 | Window Closed / Lapsed |