US2641329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loud-speaker diaphragm with transversely arched stiffener means
Assignee: LOUDSPEAKERS Inc, University of
•
Filing: 1950-05-29
•
Granted: 1953-06-09
•
Expires: 1970-05-29
Abstract
No abstract record available.
Inventors
- 👤 Sidney E Levy
- 👤 Abraham B Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:29
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02; H04R7/12; H04R7/122
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1673939A
Cited
US1876306A
Cited
US1757719A
Cited
US1846937A
Cited
GB368344A
Cited
US2007747A
Cited
US2070977A
Cited
US2141423A
Cited
US2124834A
Cited
US2269284A
Cited
US2231479A
Cited
US2193399A
Cited
GB611056A
Cited
US2580439A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-08 | 1956-12-08 | 1957-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-08 | 1960-12-08 | 1961-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-08 | 1964-12-08 | 1965-06-09 | $7700.00 | Window Closed / Lapsed |