Patent US3817631A successfully refreshed from Google Patents.
Patent US2536664A successfully refreshed from Google Patents.
US2536664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereophonic sound system for recordings
Assignee: RCA Corp
•
Filing: 1945-09-10
•
Granted: 1951-01-02
•
Expires: 1965-09-10
Abstract
No abstract record available.
Inventors
- 👤 Chester M Sinnett
- 👤 Belar Herbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:00
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/68; G; G11; G11B; G11B23/00; G11B23/18; G11B3/00; H04; H04S; H04S1/00; Y; Y10; Y10S; Y10S84/00; Y10S84/09
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1675894A
Cited
US1685357A
Cited
US1855149A
Cited
US1707260A
Cited
US1799795A
Cited
US1797317A
Cited
US1910254A
Cited
US2114019A
Cited
US2292014A
Cited
US2261628A
Cited
US2258662A
Cited
US2343471A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-01-01 | 1954-07-03 | 1955-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-01-01 | 1958-07-03 | 1959-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-01-01 | 1962-07-03 | 1963-01-02 | $7700.00 | Window Closed / Lapsed |