Patent US2771577A successfully refreshed from Google Patents.
US2771577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic switching circuits
Assignee: Fkg Fritz Kesselring Geratebau AG
•
Filing: 1951-07-20
•
Granted: 1956-11-20
•
Expires: 1971-07-20
Abstract
No abstract record available.
Inventors
- 👤 Kesselring Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:55
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/02; H02M7/40
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US684378A
Cited
US1265354A
Cited
US2094361A
Cited
US2293296A
Cited
US2465682A
Cited
US2381309A
Cited
US2617974A
Cited
US2610231A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-11-20 | 1960-05-21 | 1960-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-11-20 | 1964-05-21 | 1964-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-11-20 | 1968-05-21 | 1968-11-20 | $7700.00 | Window Closed / Lapsed |