Patent US4492575A successfully refreshed from Google Patents.
Patent US2425981A successfully refreshed from Google Patents.
US2425981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Balanced frequency discriminator
Assignee: Hartford National Bank and Trust Co
•
Filing: 1943-10-27
•
Granted: 1947-08-19
•
Expires: 1963-10-27
Abstract
No abstract record available.
Inventors
- 👤 Bard Elliott
- 👤 Kobilsky Manuel Julio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:47
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/042
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2233198A
Cited
US2233778A
Cited
US2237522A
Cited
US2274184A
Cited
US2261286A
Cited
US2286377A
Cited
US2322588A
Cited
US2282092A
Cited
US2285957A
Cited
US2354827A
Cited
US2323596A
Cited
US2379748A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-08-18 | 1951-02-17 | 1951-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-08-18 | 1955-02-17 | 1955-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-08-18 | 1959-02-17 | 1959-08-19 | $7700.00 | Window Closed / Lapsed |