Patent US4221773A successfully refreshed from Google Patents.
US4221773A
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Method of producing a carbon diaphragm for an acoustic instrument
Assignee: Pioneer Corp
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Filing: 1978-12-13
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Granted: 1980-09-09
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Expires: 1998-12-13
Abstract
Abstract A method of producing a diaphragm of an acoustic instrument having the steps of blending powders of carbon such as graphite, carbon black or the like and a thermoplastic or a thermosetting resin, shaping the resultant blend into a desired form and then carbonizing the shaped blend. As a result, it has become possible to produce a diaphragm of an acoustic instrument, having a light weight, high rigidity and a large ratio of Young's modulus to density.
Inventors
- 👤 Tsunehiro Tsukagoshi
- 👤 Teruo Toma
- 👤 Shinichi Yokozeki
- 👤 Toshikazu Yoshino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:02
CPC Classifications
H; H04; H04R; H04R31/00; H04R31/003; G; G10; G10K; G10K13/00; H04R7/00; H04R7/02
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
69 words
A method of producing a diaphragm of an acoustic instrument comprising the steps of blending and kneading scale-like graphite powder and a thermoplastic resin with each other, rolling the resulting blend into a plate form to orient the graphite, making the plate form infusible by baking the form, and carbonizing the rolled blend, thereby producing a diaphragm which is substantially distortion-free and has a high specific modulus of elasticity.
Claim 2
Independent Claim
69 words
A method of producing a diaphragm of an acoustic instrument comprising the steps of blending and kneading scale-like graphite powder and a thermoplastic resin with each other, rolling the resulting blend into a plate form to orient the graphite, making the plate form infusible by baking the form, and carbonizing the rolled blend, thereby producing a diaphragm which is substantially distortion-free and has a high specific modulus of elasticity.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1, wherein said scale-like graphite powder has a grain size of 0.1 to 100 microns.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 1, wherein said scale-like graphite powder has a grain size of 0.1 to 5 microns.
Claim 5
Dependent Claim
29 words
A method as claimed in claim 1, wherein said blend includes 10 to 90 parts by weight of graphite and 90 to 10 parts by weight of the resin.
Claim 6
Dependent Claim
30 words
A method as claimed in claim 1, wherein said blend preferably includes 40 to 70 parts by weight of graphite and 60 to 30 parts by weight of the resin.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1, wherein said thermoplastic resin is a resin selected from a group consisting of vinyl, silicone, and acryl resins.
Claim 8
Dependent Claim
22 words
A method as claimed in claim 6, wherein said vinyl resin is selected from a group consisting of vinyl chloride and styrene.
Claim 9
Dependent Claim
14 words
A method as claimed in claim 6, wherein said silicone resin includes trimethylchlorosilane compound.
Claim 10
Dependent Claim
14 words
A method as claimed in claim 6, wherein said acryl resin includes polymethyl methacrylate.
Claim 11
Dependent Claim
20 words
A method as claimed in claim 1, wherein said blend includes about 1.9 to about 25% by weight of plasticizer.
Claim 12
Dependent Claim
20 words
A method as claimed in claim 1, wherein said blend includes about 45 to about 61% by weight of solvent.
Claim 13
Dependent Claim
22 words
A method as claimed in claim 1, wherein said blend includes a stabilizer in an amount sufficient to provide the stabilizing effect.
Claim 14
Dependent Claim
31 words
A method as claimed in claim 1, wherein said carbonizing step includes a step of heating the plate form at 1000° to 1500° C. for one hour, in a non-oxidizing atmosphere.
Claim 15
Dependent Claim
41 words
A method as claimed in claim 13, wherein said baking step comprises raising the temperature in an oxidizing atmosphere at a rate of 1° to 20° C./hour up to 400° C. and at a rate of 10° to 100° C. thereafter.
Claim 16
Dependent Claim
32 words
A method as claimed in claim 1 further comprising after said rolling, shaping of said plate form by vacuum, or a press at a temperature of the softening point of the blend.
Claim 17
Dependent Claim
69 words
A diaphragm for use in an acoustic instrument, said diaphragm being made by a process comprising blending and kneading scale like graphite powder with a thermoplastic resin, rolling the resulting blend into a plate form, making the plate form infusible by baking the form and carbonizing the rolled blend wherein the graphite scales are oriented and the diaphragm is substantially distortion-free and has a high specific modulus of elasticity.
Claim 18
Dependent Claim
69 words
A diaphragm for use in an acoustic instrument, said diaphragm being made by a process comprising blending and kneading scale like graphite powder with a thermoplastic resin, rolling the resulting blend into a plate form, making the plate form infusible by baking the form and carbonizing the rolled blend wherein the graphite scales are oriented and the diaphragm is substantially distortion-free and has a high specific modulus of elasticity.
Claim 19
Dependent Claim
37 words
The diaphragm of claim 16 wherein said blend includes 10 to 90 parts by weight of graphite having a particle size of 0.1 to 100 microns and 90 to 10 parts by weight of said thermoplastic resin.
Claim 20
Dependent Claim
38 words
A diaphragm of claim 16 wherein said baking step comprises increasing the temperature in an oxidizing atmosphere at a rate of 1° to 20°/hour up to 400° C. and at a rate of 10° to 100° C. thereafter.
Claim 21
Dependent Claim
34 words
The diaphragm of claim 17 wherein said blend includes 40-70 parts by weight of graphite having a particle size of 0.1 to 5 microns and 60 to 30 parts by weight of the resin.
Claim 22
Dependent Claim
21 words
The diaphragm of claim 16 wherein said thermoplastic resin is selected from the group consisting of vinyl, silicone and acryl resins.
Claim 23
Dependent Claim
22 words
The diaphragm of claim 20 wherein said resin is selected from the group consisting of vinyl chloride, styrene, trimethylchlorosilane, and polymethyl methacrylate.
Claim 24
Dependent Claim
26 words
The diaphragm of claim 16 wherein said blend further includes about 1.9% to 25% by weight of a plasticizer and a stabilizing amount of a stabilizer.
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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) | 1983-09-09 | 1984-03-10 | 1984-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-09 | 1988-03-10 | 1988-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-09 | 1992-03-10 | 1992-09-09 | $7700.00 | Window Closed / Lapsed |