Patent US2217446A successfully refreshed from Google Patents.
US2217446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc-back indicator
Assignee: Westinghouse Electric Corp
•
Filing: 1938-03-31
•
Granted: 1940-10-08
•
Expires: 1958-03-31
Abstract
No abstract record available.
Inventors
- 👤 Leon R Ludwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:45
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/1209; H01; H01J; H01J13/00; H01J13/02; H01J13/48
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1943-10-08 | 1944-04-08 | 1944-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-10-08 | 1948-04-08 | 1948-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-10-08 | 1952-04-08 | 1952-10-08 | $7700.00 | Window Closed / Lapsed |