US4412675A
Expired / Lapsed
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Carbon spring and process for preparing the same
Assignee: MIRSUBISHI PENCIL Co Ltd
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Filing: 1981-07-27
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Granted: 1983-11-01
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Expires: 2001-07-27
Abstract
Abstract A carbon spring composed substantially of carbonaceous carbon or graphite carbon is prepared by shaping an organic linear material to a coiled spring and thereafter heating it to carbonize.
Inventors
- 👤 Takamasa Kawakubo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:26
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/524; C04B35/71; C04B35/78; C04B35/80; C04B35/83; F; F16; F16F; F16F1/00; F16F1/02; F16F1/021; F16F1/04
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
77 words
A carbon spring prepared by a process, comprising: shaping an organic linear material, the organic constituent of which is selected from the group consisting of a thermoplastic resin, a thermosetting resin, a pitch, a natural high molecular weight substance, a synthetic high molecular weight substance containing a condensed polycyclic aromatic base structure which is high in carbon yield and mixtures thereof, into the form of a coiled spring; and then carbonizing the spring shaped organic linear material.
Claim 2
Dependent Claim
77 words
A carbon spring prepared by a process, comprising: shaping an organic linear material, the organic constituent of which is selected from the group consisting of a thermoplastic resin, a thermosetting resin, a pitch, a natural high molecular weight substance, a synthetic high molecular weight substance containing a condensed polycyclic aromatic base structure which is high in carbon yield and mixtures thereof, into the form of a coiled spring; and then carbonizing the spring shaped organic linear material.
Claim 3
Dependent Claim
36 words
The carbon spring of claim 1, wherein said pitch is petroleum asphalt, coal tar pitch, cracked naphtha pitch or a carbonized material of a hydrocarbon compound of petroleum asphalt, coal tar pitch or a synthetic resin.
Claim 4
Dependent Claim
29 words
The carbon spring of claim 1, wherein said natural organic high molecular weight substance is lignin, cellulose, tragacanth gum, gum arabi, natural rubber or humic acid and derivatives thereof.
Claim 5
Dependent Claim
35 words
The carbon spring of claim 1, wherein said synthetic high molecular weight substance is a formalin condensate of naphthalene sulfonic acid, dinitronaphthalene or indanthrene vat dyes derived from pyrene, pyranthrone, violanthrone, benzanthrone or intermediates thereof.
Claim 6
Dependent Claim
46 words
The carbon spring of claim 1, wherein said thermoplastic resin is polyvinyl chloride, polyacrylonitrile, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl pyrrolidone, ethyl cellulose, polyvinyl chloride-vinyl acetate copolymer, polyacrylonitrile-styrene copolymer, polyacrylonitrile-vinyl chloride copolymer, polyamide, carboxymethylcellulose, polyphenylene oxide, polyparaxylene, polysulfone, polyimide, polyamideimide, polyester imide, polybenzimidazole or polyoxadiazole.
Claim 7
Dependent Claim
28 words
The carbon spring of claim 1, wherein said thermosetting resin is a phenol resin, an epoxy resin, a xylene resin, an alkyd resin or an unsaturated polyester resin.
Claim 8
Dependent Claim
27 words
The carbon spring of claim 1, wherein said organic linear material is further composed of carbon fibers, graphite whiskers, or crystalline graphite powder as a reinforcing material.
Claim 9
Dependent Claim
21 words
The carbon spring of claim 7, wherein said reinforcing material comprises 20 to 80% by weight of the organic linear material.
Claim 10
Dependent Claim
79 words
A process for fabricating a coiled carbon spring, which comprises: shaping an organic linear material, the organic constituent of which is selected from the group consisting of a thermoplastic resin, a thermosetting resin, a pitch, a natural high molecular weight substance, a synthetic high molecular weight substance containing a condensed polycyclic aromatic base structure which is high in carbon yield and mixtures thereof, into the form of a coiled spring; and then carbonizing the spring shaped organic linear material.
Claim 11
Dependent Claim
79 words
A process for fabricating a coiled carbon spring, which comprises: shaping an organic linear material, the organic constituent of which is selected from the group consisting of a thermoplastic resin, a thermosetting resin, a pitch, a natural high molecular weight substance, a synthetic high molecular weight substance containing a condensed polycyclic aromatic base structure which is high in carbon yield and mixtures thereof, into the form of a coiled spring; and then carbonizing the spring shaped organic linear material.
Claim 12
Dependent Claim
28 words
The process of claim 9, wherein said carbonization step comprises heating said shaped organic linear material to a temperature of 500° to 1500° C. in an inert atmosphere.
Claim 13
Dependent Claim
32 words
The process of claim 10, wherein said carbonized organic linear material is further heated to a temperature of 2000° to 3000° C. in an inert atmosphere to further complete the carbonization process.
Claim 14
Dependent Claim
42 words
The process of claim 9, wherein after shaping said organic linear material into the shape of a coiled spring, the organic linear material is heated to a temperature of 50° to 300° C. in an active or inert atmosphere prior to carbonization.
Claim 15
Dependent Claim
31 words
The process of claim 9, wherein said organic linear material is cured by a crosslinking reaction after said organic linear material is shaped, but before carbonization of said organic linear material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |