US2690231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic device
Assignee: LOUDSPEAKERS Inc, University of
•
Filing: 1950-03-09
•
Granted: 1954-09-28
•
Expires: 1970-03-09
Abstract
No abstract record available.
Inventors
- 👤 Sidney E Levy
- 👤 Saul J White
- 👤 Abraham B Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:19
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/28; H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/345
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1314980A
Cited
US1477556A
Cited
US1747830A
Cited
US1754425A
Cited
US1689009A
Cited
FR775561A
Cited
US2537141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-09-27 | 1958-03-29 | 1958-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-09-27 | 1962-03-29 | 1962-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-09-27 | 1966-03-29 | 1966-09-28 | $7700.00 | Window Closed / Lapsed |