Patent US4972331A successfully refreshed from Google Patents.
Patent US2504804A successfully refreshed from Google Patents.
US2504804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical protective apparatus
Assignee: Nortel Networks Ltd
•
Filing: 1948-12-11
•
Granted: 1950-04-18
•
Expires: 1968-12-11
Abstract
No abstract record available.
Inventors
- 👤 John L Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:24
CPC Classifications
H; H01; H01T; H01T4/00; H01T4/08; H01H; H01H85/00; H01H85/02; H01H85/44
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-04-17 | 1953-10-17 | 1954-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-04-17 | 1957-10-17 | 1958-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-04-17 | 1961-10-17 | 1962-04-18 | $7700.00 | Window Closed / Lapsed |