US4040823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing an electrical resistant fluid-permeable heat generating member
Assignee: Individual
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Filing: 1976-04-09
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Granted: 1977-08-09
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Expires: 1996-04-09
Abstract
Abstract A fluid-permeable electrically energized heat generating member of a desired shape, such as a rectangular brick, is formed by (1) mixing (a) about 87 to 94% by weight of a first material which contains about 80 to 95% by weight of SiC and about 5 to 20% by weight of a mixture of carbonyl iron, nickel-chromium alloy, cobalt and carbon; (b) about 5 to 10% by weight of a second material which contains about 75 to 95% by weight of an organic binder material, such as a linseed oil and about 5 to 25% by weight of a foaming material, such as methylene diphenyl isocyanate; and (c) about 0.2 to 3% by weight of a third material selected from the group consisting of polystyrene preformed powder, sawdust, wood flour, starch, corn flour and mixtures thereof; (2) placing the resultant mixture in a select mold and subjecting the mold to curing conditions sufficient to provide self-sustaining members composed of the foregoing mixture; (3) removing the self-sustaining members from the molds and subjecting them to a heat at a temperature in the range of about 250° to 350° F. for a period of time sufficient to render the bodies electrically conductive; (4) sintering the electrically conductive bodies as by passing a controlled electrical current through each member until a temperature in the range of about 1000° to 1600° F. is achieved within the member; and (5) metallizing terminal sides of each member, as by applying an aluminum layer thereon for contact with a suitable electrical circuit.
Inventors
- 👤 Takeshi Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:10
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/10; B22F3/11; B22F3/1121; C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; F; F24; F24H; F24H1/00; F24H1/10; F24H1/101; H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/148; B22F2998/00; H05B2203/00; H05B2203/021
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
258 words
A method of manufacturing sintered electrically resistive fluid-permeable heat generating members comprising the sequential steps of: I. mixing a starting material mixture into a substantially homogeneous mass, said starting material mixture being composed of: A about 87% to 94% by weight of said starting mixture of a first material comprised of about 80% to 95% by weight of silicon carbide particles and about 50% to 20% by weight of a mixture of carbonyl iron particles, nickel-chromium alloy particles, metallic cobalt particles and carbon particles; B. about 5% to 10% by weight of said starting mixture of a second material comprised of about 75% to 95% by weight of a liquid organic binder and about 5% to 25% by weight of an isocyanate; C. about 0.2% to 3% by weight of said starting mixture of a third material selected from the group consisting of polystyrene powder, sawdust, wood flour, starch, corn flour and mixtures thereof; Ii. placing said homogeneous mass into selected molds and subjecting said filled molds to initial curing conditions sufficient to form self-sustaining members from said homogeneous mass: Iii. removing the self-sustaining members from said molds and subjecting said members to further curing conditions sufficient to impart electrical conductivity characteristics to said members; and Iv. sintering the electrically conductive members by gradually heating said members to a temperature in the range of about 1000° to 1600° F. and maintaining said conditions for a period of time sufficient to substantially destroy all organic material within said members and sinter the remaining materials into a uniformly porous body.
Claim 2
Independent Claim
258 words
A method of manufacturing sintered electrically resistive fluid-permeable heat generating members comprising the sequential steps of: I. mixing a starting material mixture into a substantially homogeneous mass, said starting material mixture being composed of: A about 87% to 94% by weight of said starting mixture of a first material comprised of about 80% to 95% by weight of silicon carbide particles and about 50% to 20% by weight of a mixture of carbonyl iron particles, nickel-chromium alloy particles, metallic cobalt particles and carbon particles; B. about 5% to 10% by weight of said starting mixture of a second material comprised of about 75% to 95% by weight of a liquid organic binder and about 5% to 25% by weight of an isocyanate; C. about 0.2% to 3% by weight of said starting mixture of a third material selected from the group consisting of polystyrene powder, sawdust, wood flour, starch, corn flour and mixtures thereof; Ii. placing said homogeneous mass into selected molds and subjecting said filled molds to initial curing conditions sufficient to form self-sustaining members from said homogeneous mass: Iii. removing the self-sustaining members from said molds and subjecting said members to further curing conditions sufficient to impart electrical conductivity characteristics to said members; and Iv. sintering the electrically conductive members by gradually heating said members to a temperature in the range of about 1000° to 1600° F. and maintaining said conditions for a period of time sufficient to substantially destroy all organic material within said members and sinter the remaining materials into a uniformly porous body.
Claim 3
Dependent Claim
41 words
A method as defined in claim 1, wherein step (II) initial curing conditions comprise heating the filled molds at a temperature in the range of about 200° to 300° F. for a period of time of about 5 to 10 minutes.
Claim 4
Dependent Claim
41 words
A method as defined in claim 1, wherein step (III) further curing conditions comprise heating the self-sustaining members at a temperature in the range of about 250° to 350° F. for a period of time of about 45 to 75 minutes.
Claim 5
Dependent Claim
78 words
A method as defined in claim 1, wherein step (IV) comprises connecting each electrically conductive member to a controllable electrical current and passing an electrical current of an initial voltage of about 10 to 15 volts through each member and raising said voltage about 10 to 15 volts approximately every 30 minutes until a voltage of about 80 to 120 volts is attained within about 4 hours and maintaining the attained voltage for about 1 to 3 hours.
Claim 6
Dependent Claim
32 words
A method as defined in claim 4, wherein step (IV) includes placing the electrically conductive members in a protective environment for preventing oxidation of materials within said members during the sintering step.
Claim 7
Dependent Claim
47 words
A method as defined in claim 1, wherein step (IV) comprises heating the electrically conductive members from room temperature to about 1000° to 1600° F. over a period of time of about 2 to 4 hours and maintaining the attained temperature for about 1 to 3 hours.
Claim 8
Dependent Claim
32 words
A method as defined in claim 6, wherein step (IV) includes placing the electrically conductive members in a protective environment for preventing oxidation of materials within said members during the sintering step.
Claim 9
Dependent Claim
34 words
A method as defined in claim 1, which includes applying an electrically conductive metal layer to opposing sides of the sintered members for connection with a select electrical circuit capable of heating said members.
Claim 10
Dependent Claim
15 words
A method as defined in claim 8, wherein the metal layer is composed of aluminum.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |