Patent US2991397A successfully refreshed from Google Patents.
US2991397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective system for detecting breakdown resistance that would cause a short or ground of a power circuit
Assignee: Femco Inc
•
Filing: 1957-10-31
•
Granted: 1961-07-04
•
Expires: 1977-10-31
Abstract
No abstract record available.
Inventors
- 👤 Place Willard Porter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:02
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/16; H02H3/17
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1831338A
Cited
GB637392A
Cited
US2525393A
Cited
US2528237A
Cited
US2677014A
Cited
US2874337A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-03 | 1965-01-02 | 1965-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-03 | 1969-01-02 | 1969-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-03 | 1973-01-02 | 1973-07-04 | $7700.00 | Window Closed / Lapsed |