Method of manufacturing electric resistors
OwnerYasuo Ikedainventor
Life of this patent
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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.
Claims11
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;
- e. sintering said compressed body to form a sintered body;
- and
- f. cutting said sintered body into at least one flat, flexible electrical resistor.
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.
Dependencies are inferred from the claim text.