US2491918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereophonic receiving system
Assignee: —
•
Filing: —
•
Granted: 1949-12-20
•
Expires: 1966-12-20
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:56
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/86; H04H20/88
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1641431A
Cited
US2004107A
Cited
US1854247A
Cited
US2004126A
Cited
US1922059A
Cited
US1940097A
Cited
US1914103A
Cited
US2027022A
Cited
US2352696A
Cited
US2305917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-12-19 | 1953-06-20 | 1953-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-12-19 | 1957-06-20 | 1957-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-12-19 | 1961-06-20 | 1961-12-20 | $7700.00 | Window Closed / Lapsed |