US4412103A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm for an electro-acoustic transducer
Assignee: Kuraray Co Ltd
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Filing: 1982-03-19
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Granted: 1983-10-25
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Expires: 2002-03-19
Abstract
Abstract A diaphragm for an electro-acoustic transducer comprising a sheet formed from a mixture of a polymer and mica, where the sheet contains (a) 30 to 95% by weight of a polymer selected from among polyolefins, polyesters, and polyamides and (b) 5 to 70% by weight of mica having a weight-average flake diameter not exceeding 500 microns and a weight-average aspect ratio of at least 10. By adding the specified mica, the sheet has a drastically improved dynamic modulus and a substantially unchanged loss tangent.
Inventors
- 👤 Kiyonobu Fujii
- 👤 Kotaro Ikeda
- 👤 Kenji Okuno
- 👤 Koichi Saito
- 👤 Osamu Ohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:35
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A moving coil loudspeaker comprising a diaphragm for an electro-acoustic transducer wherein said diaphragm comprises a sheet formed from a mixture of a polymer and mica, wherein said sheet comprises: (a) 30 to 95% by weight of a polymer selected from the group consisting of polyolefins, polyesters, and polyamides; and (b) 5 to 70% by weight of mica having a weight-average flake diameter of no more than 500 microns and a weight-average aspect ratio of at least 10.
Claim 2
Dependent Claim
78 words
A moving coil loudspeaker comprising a diaphragm for an electro-acoustic transducer wherein said diaphragm comprises a sheet formed from a mixture of a polymer and mica, wherein said sheet comprises: (a) 30 to 95% by weight of a polymer selected from the group consisting of polyolefins, polyesters, and polyamides; and (b) 5 to 70% by weight of mica having a weight-average flake diameter of no more than 500 microns and a weight-average aspect ratio of at least 10.
Claim 3
Dependent Claim
14 words
A loudspeaker as set forth in claim 1, wherein said polymer is a polyolefin.
Claim 4
Dependent Claim
31 words
A loudspeaker as set forth in claim 2, wherein said polyolefin is selected from the group consisting of polypropylene and crystallizable copolymers containing at least 50 mol % of propylene units.
Claim 5
Dependent Claim
22 words
A loudspeaker as set forth in claim 3, wherein said polyolefin has a melt index of no more than 3.5 g/10 min.
Claim 6
Dependent Claim
14 words
A loudspeaker as set forth in claim 1, wherein said polymer is a polyester.
Claim 7
Dependent Claim
23 words
A loudspeaker as set forth in claim 5, wherein said polyester is selected from the group consisting of polyethylene terephthalate and polybutylene terephthalate.
Claim 8
Dependent Claim
14 words
A loudspeaker as set forth in claim 1, wherein said polymer is a polyamide.
Claim 9
Dependent Claim
23 words
A loudspeaker as set forth in claim 7, wherein said polyamide is selected from the group consisting of nylon 6 and nylon 6/6.
Claim 10
Dependent Claim
18 words
A loudspeaker as set forth in claim 1, wherein said mica is treated with a silane coupling agent.
Claim 11
Dependent Claim
29 words
A loudspeaker as set forth in claim 1, wherein said sheet comprises 40 to 90% by weight of said polymer, and 10 to 60% by weight of said mica.
Claim 12
Dependent Claim
18 words
A loudspeaker as set forth in claim 1, wherein said sheet is obtained by melt forming said mixture.
Claim 13
Dependent Claim
16 words
A loudspeaker as set forth in claim 11, wherein said sheet is formed by melt extrusion.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |