US2746558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reflex type loudspeakers
Assignee: LOUDSPEAKERS Inc, University of
•
Filing: 1952-06-24
•
Granted: 1956-05-22
•
Expires: 1972-06-24
Abstract
No abstract record available.
Inventors
- 👤 Sidney E Levy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:14
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/02; G10K11/025
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1170800A
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US1625325A
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GB246634A
Cited
GB243968A
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FR606003A
Cited
US1653144A
Cited
US2026919A
Cited
GB636245A
Cited
US2551177A
Cited
US2494134A
Cited
US2659590A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-05-22 | 1959-11-21 | 1960-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-22 | 1963-11-21 | 1964-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-22 | 1967-11-21 | 1968-05-22 | $7700.00 | Window Closed / Lapsed |