Patent US3930130A successfully refreshed from Google Patents.
US3930130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbon fiber strengthened speaker cone
Assignee: BP Corp North America Inc
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Filing: 1973-09-21
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Granted: 1975-12-30
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Expires: 1993-09-21
Abstract
Abstract A novel speaker diaphragm having a high specific modulus for use in conventional loudspeakers including the magnetic and electrostatic type loudspeakers, the diaphragm comprising a carbonaceous fibrous web impregnated by a resin. The speaker diaphragm has a sonic velocity that is comparable to or exceeds that of a speaker diaphragm made of aluminum.
Inventors
- 👤 Samuel M Boszor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:43
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
87 words
A LOUDSPEAKER DIAPHRAGM, SAID DIAPHRAGM CONSISTING ESSENTIALLY OF A CARBONACEOUS FIBROUS WEB OF CARBON FIBERS AND A RESIN, SAID CARBON FIBERS REPRESENTING BETWEEN ABOUT 30% AND ABOUT 70% BY VOLUME OF SAID DIAPHRAGM, THE BALANCE BEING SAID RESIN, SAID DIAPHRAGM HAVING A YOUND''S MODULUS BETWEEN ABOUT 3 MILLION PSI AND ABOUT 30 MILLIONS PSI AND A DENSITY BETWEEN ABOUT 0.8 GM/CM2 AND ABOUT 1.7 GM/CM3 SO AS TO PROVIDE A SONIC VELOCITY FOR SAID DIAPHRAGM BETWEEN ABOUT 2.5 X 10**5 CM/SEC AND ABOUT 11 X 10**5 CM/SEC.
Claim 2
Dependent Claim
87 words
A LOUDSPEAKER DIAPHRAGM, SAID DIAPHRAGM CONSISTING ESSENTIALLY OF A CARBONACEOUS FIBROUS WEB OF CARBON FIBERS AND A RESIN, SAID CARBON FIBERS REPRESENTING BETWEEN ABOUT 30% AND ABOUT 70% BY VOLUME OF SAID DIAPHRAGM, THE BALANCE BEING SAID RESIN, SAID DIAPHRAGM HAVING A YOUND''S MODULUS BETWEEN ABOUT 3 MILLION PSI AND ABOUT 30 MILLIONS PSI AND A DENSITY BETWEEN ABOUT 0.8 GM/CM2 AND ABOUT 1.7 GM/CM3 SO AS TO PROVIDE A SONIC VELOCITY FOR SAID DIAPHRAGM BETWEEN ABOUT 2.5 X 10**5 CM/SEC AND ABOUT 11 X 10**5 CM/SEC.
Claim 3
Dependent Claim
15 words
A diaphragm as defined in claim 1 wherein said carbon fibers are staple carbon fibers.
Claim 4
Dependent Claim
24 words
A diaphragm as defined in claim 2 wherein said resin is a resin selected from the group consisting of epoxy, furane, phenolic and melamine.
Claim 5
Dependent Claim
23 words
A diaphragm as defined in claim 3 wherein staple pitch fibers represent between about 60% to about 70% by volume of said diaphragm.
Claim 6
Dependent Claim
22 words
A diaphragm as defined in claim 1 wherein the sonic velocity of said diaphragm is greater than about 4.6 X 105 cm/sec.
Claim 7
Dependent Claim
18 words
A diaphragm as defined in claim 1 having a thickness between about 0.005 inches and about 0.025 inches.
Claim 8
Dependent Claim
14 words
A diaphragm as defined in claim 1 wherein said loudspeaker is an electrostatic loudspeaker.
Claim 9
Dependent Claim
18 words
A diaphragm as defined in claim 11 having a thickness between about 0.005 inches and about 0.010 inches.
Claim 10
Dependent Claim
14 words
A diaphragm as defined in claim 8 wherein said thickness is about 0.007 inches.
Claim 11
Dependent Claim
23 words
A diaphragm as defined in claim 1 wherein said carbon fibers represent between about 60% and about 70% by volume of said diaphragm.
Claim 12
Dependent Claim
19 words
A diaphragm as defined in claim 5 wherein said sonic velocity is greater than about 10 X 105 cm/sec.
References Cited (Backward Citations)
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US3367812A
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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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |