Patent US3578104A successfully refreshed from Google Patents.
US3578104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudspeaker
Assignee: Nippon Gakki Co Ltd
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Filing: 1969-05-12
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Granted: 1971-05-11
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Expires: 1989-05-12
Abstract
Abstract In a loudspeaker including a cap made of relatively rigid foamed plastics such as foamed polystyrene, an improvement comprising a small piece of rubberlike elastomer having relatively high specific gravity adhered to a central portion of said cap, thereby improving its frequency characteristic especially in a high frequency sound range.
Inventors
- 👤 Hiromi Sotome
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:35
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
61 words
In a loudspeaker having a generally conical diaphragm of relatively rigid foamed plastics material with a cap of relatively rigid foamed plastic material fixedly mounted across the smaller end of the diaphragm, the improvement comprising a small piece of rubberlike elastomer having relatively high specific gravity and adhered to a central portion of the surface of said cap opposite said diaphragm.
Claim 2
Dependent Claim
61 words
In a loudspeaker having a generally conical diaphragm of relatively rigid foamed plastics material with a cap of relatively rigid foamed plastic material fixedly mounted across the smaller end of the diaphragm, the improvement comprising a small piece of rubberlike elastomer having relatively high specific gravity and adhered to a central portion of the surface of said cap opposite said diaphragm.
References Cited (Backward Citations)
US3111187A
Cited
US3093207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |