US2589133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical filter
Assignee: Individual
•
Filing: 1948-01-13
•
Granted: 1952-03-11
•
Expires: 1968-01-13
Abstract
No abstract record available.
Inventors
- 👤 Ellison S Purington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:45
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1313070A
Cited
US1678653A
Cited
US1759952A
Cited
US1689318A
Cited
US1902031A
Cited
US2425968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-03-11 | 1955-09-10 | 1956-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-03-11 | 1959-09-10 | 1960-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-03-11 | 1963-09-10 | 1964-03-11 | $7700.00 | Window Closed / Lapsed |