US4055615A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing electric resistors
Assignee: Individual
•
Filing: 1974-09-17
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Granted: 1977-10-25
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Expires: 1994-09-17
Abstract
Abstract An electrical resistor is manufactured by molding a mixture of the powders of tetrafluoropolyethylene, carbon and metal and then sintering the molded body. Terminals comprising a mixture of a powder of tetrafluoropolyethylene and a powder of soft metal are provided by simultaneously molding a lamination of the first mentioned mixture and the second mentioned mixture.
Inventors
- 👤 Yasuo Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:09
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/30
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
102 words
A method of manufacturing a thin, flat, flexible electrical resistor heating element for use in electric blankets, said method comprising the steps of: a. mixing tetrafluoropolyethylene powder and a mixture of carbon powder and metal powder to form an admixture, said mixture of carbon and metal powders not exceeding 30% by volume of said tetrafluoropolyethylene powder in said admixture; b. charging said powder admixture in a metal mold; c. compressing said powder admixture in said mold for a sufficient time interval to eliminate air voids and bond said powder admixture into a compressed body; d. removing said compressed body from said mold;
Claim 2
Independent Claim
102 words
A method of manufacturing a thin, flat, flexible electrical resistor heating element for use in electric blankets, said method comprising the steps of: a. mixing tetrafluoropolyethylene powder and a mixture of carbon powder and metal powder to form an admixture, said mixture of carbon and metal powders not exceeding 30% by volume of said tetrafluoropolyethylene powder in said admixture; b. charging said powder admixture in a metal mold; c. compressing said powder admixture in said mold for a sufficient time interval to eliminate air voids and bond said powder admixture into a compressed body; d. removing said compressed body from said mold;
Claim 3
Dependent Claim
24 words
e. sintering said compressed body to form a sintered body; and f. cutting said sintered body into at least one flat, flexible electrical resistor.
Claim 4
Dependent Claim
24 words
e. sintering said compressed body to form a sintered body; and f. cutting said sintered body into at least one flat, flexible electrical resistor.
Claim 5
Dependent Claim
20 words
The method according to claim 1 wherein said metal is selected from group consisting of copper, silver, gold and brass.
Claim 6
Dependent Claim
17 words
The method according to claim 1 wherein said powder of metal is in the form of flakes.
Claim 7
Dependent Claim
22 words
The method according to claim 1 wherein said compressed body is sintered at a temperature of from 320° C to 390° C.
Claim 8
Dependent Claim
22 words
The method according to claim 1 wherein said molding is performed under a pressure of from 600 to 700 kg/cm 2 .
Claim 9
Dependent Claim
15 words
The method according to claim 1 wherein said interval ranges from 5 to 7 minutes.
Claim 10
Dependent Claim
36 words
The method according to claim 1 wherein a hollow cylindrical sintered body is formed, the body is sliced into annular discs, and the annular discs are then formed with radial gaps thereby forming substantially annular resistors.
Claim 11
Dependent Claim
32 words
A method according to claim 1 wherein a hollow cylindrical sintered body is formed and then the cylindrical sintered body is cut spirally along its periphery to form a flexible web-shaped resistor.
Claim 12
Independent Claim
221 words
A method of concurrently manufacturing a thin, flat, flexible electrical resistor and integral terminals for use in electric blankets, said electric resistor having a resistance value sufficiently high to serve as a heating element and said terminals having a substantially lower resistance value to avoid heating thereof, said process comprising the steps of: a. mixing tetrafluoropolyethylene powder and a mixture of carbon powder and metal powder to form a first admixture to be formed into said flexible resistor, said mixture of carbon and metal powders not exceeding 17% by volume of said tetrafluoropolyehtylene powder in said first admixture; b. mixing tetrafluoropolyethylene powder and electroconductive metal powder to form a second admixture to be formed into said terminals; c. charging said first and second powder admixtures in a metal mold in a predetermined order such that said first powder admixture is located between spaced portions of said second powder admixture to form a powder admixture body; d. compressing said powder admixture body in said mold for a sufficient time interval to eliminate air voids and bond said first and second powder admixtures into a compressed body; e. removing said compressed body from said mold; f. sintering said compressed body to form a sintered body; and g. cutting said sintered body into at least one flat, flexible electrical resistor with integral spaced terminals.
Claim 13
Independent Claim
221 words
A method of concurrently manufacturing a thin, flat, flexible electrical resistor and integral terminals for use in electric blankets, said electric resistor having a resistance value sufficiently high to serve as a heating element and said terminals having a substantially lower resistance value to avoid heating thereof, said process comprising the steps of: a. mixing tetrafluoropolyethylene powder and a mixture of carbon powder and metal powder to form a first admixture to be formed into said flexible resistor, said mixture of carbon and metal powders not exceeding 17% by volume of said tetrafluoropolyehtylene powder in said first admixture; b. mixing tetrafluoropolyethylene powder and electroconductive metal powder to form a second admixture to be formed into said terminals; c. charging said first and second powder admixtures in a metal mold in a predetermined order such that said first powder admixture is located between spaced portions of said second powder admixture to form a powder admixture body; d. compressing said powder admixture body in said mold for a sufficient time interval to eliminate air voids and bond said first and second powder admixtures into a compressed body; e. removing said compressed body from said mold; f. sintering said compressed body to form a sintered body; and g. cutting said sintered body into at least one flat, flexible electrical resistor with integral spaced terminals.
Claim 14
Dependent Claim
32 words
The method according to claim 9 wherein the amount of said electroconductive metal in said second mixture is selected to be more than 12%, by volume, of the amount of said tetrafluoropolyethylene.
Claim 15
Dependent Claim
40 words
The method according to claim 9 wherein a cylindrical sintered body is formed and then the sintered body is cut spirally along the periphery thereof to form a flexible web-shaped resistor with integral terminals on the opposite side edges thereof.
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) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |