Patent US2531505A successfully refreshed from Google Patents.
US2531505A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Noise suppression means for communication receiving apparatus
Assignee: Hitachi Rail STS USA Inc
•
Filing: 1947-10-08
•
Granted: 1950-11-28
•
Expires: 1967-10-08
Abstract
No abstract record available.
Inventors
- 👤 Kenneth E Doriot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:39
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/22; H03G3/26; H03G3/28
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2070354A
Cited
US2239901A
Cited
US2098286A
Cited
US2345966A
Cited
US2334468A
Cited
US2372934A
Cited
US2400948A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-11-27 | 1954-05-29 | 1954-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-27 | 1958-05-29 | 1958-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-27 | 1962-05-29 | 1962-11-28 | $7700.00 | Window Closed / Lapsed |