Champion Spark Plug Company

Joseph Nemeth

Charles I Kowalski

Robert H Insley

Paul E Rempes, Jr

Daniel L Tribble

Frank J Russell

Clifford C McMahon

Electrically semi-conducting and conducting open celled ceramic networks and methods for producing them are disclosed. The ceramic network is formed by impregnating an organic foam material with a semi-conducting or conducting ceramic composition, and firing the impregnated material to burn out the foam and to vitrify the ceramic. The semi-conducting or conducting ceramic composition may comprise, on a solids basis, from 45 to 80 percent of a lead-free ceramic frit, from 5 to 15 percent of mono aluminum phosphate, from 6 to 45 percent of a silicone resin, from 0.2 to 13.2 percent of a conducting carbon compound, and an organic solvent or water in an amount sufficient to form a dispersion having a viscosity ranging from 300 to 3000 centipoises, and, in the latter case, from 0.5 to 7 percent of a detergent. The electrically semi-conducting or conducting ceramic composition may also comprise, on a solids basis, a modified copper and alumina composition, from 6 to 45 percent of a silicone resin, and an organic solvent or water and detergent to produce a dispersion having a viscosity ranging from 300 to 3000 centipoises. The organic solvent systems and the aqueous systems both constitute dispersions.

Open-celled, electrically conductive ceramic network

An improved spark plug, capable of suppressing radio-frequency electromagnetic interference from internal combustion engine ignition systems such as those commonly used in motor vehicles, is disclosed. The plug comprises a shell releasably engageable with an engine, an insulator mounted in the shell, a center electrode seated within the insulator and a ground electrode structurally integral with the shell and in spark gap relationship with the center electrode. The spark plug is further characterized in that at least a portion of its insulator has a dielectric constant sufficiently high that the effective dielectric constant of the insulator is at least 30, and the relationships among the elements of the spark plug and the effective value of the dielectric constant of the insulator are such that the spark plug has a capacitance of at least 20 picofarads. Preferably, the spark plug has a capacitance of from 20 to 100 picofarads, most desirably from 30 to 80 picofarads.

Spark plug

A carbon resistor and a method for producing the resistor are disclosed. The method preferably comprises the steps of preparing a uniform, finely-divided mixture by blending a glass frit with at least one temporary binder and substantially 1/4 to 4 percent of conductive carbon, pressing a longitudinally extending shape having opposed ends from the mixture, heating the shape to 450-550 degrees F. for about 30 minutes and cooling to ambient temperature, applying a silver paint containing a lead borosilicate frit composition to the cooled shape to provide electrical contacts, and firing the shape and contacts to vitrify the frit of the resistor. A preferred lead borosilicate frit composition, by weight, consists essentially of from 5 to 15 percent of AlPO.sub.4, from 1/4 to 3 percent of conductive carbon, from 15 to 30 percent of a phenyl lower alkyl silicone resin and from 65 to 80 percent of a lead borosilicate glass frit which consists essentially of substantially 20 percent SiO.sub.2, 15 percent B.sub.2 O.sub.3, 59 percent PbO and 6 percent Na.sub.2 O.

Carbon resistor and method for producing same

A lead-free green ceramic body useful after firing as an electrical resistor, and a method for producing such a resistor, are disclosed. The method preferably comprises the steps of preparing a uniform, finely-divided mixture by blending, by weight, substantially 69 percent of a glass frit with substantially 8 percent of AlPO.sub.4, substantially 3 percent of conductive carbon and substantially 20 percent of a phenyl lower alkyl silicone resin which is curable to form a temporary binder for the conductive carbon and the glass frit. One preferred frit consists essentially of substantially 43 percent SiO.sub.2, 20 percent B.sub.2 O.sub.3, 21 percent Na.sub.2 O, 3 percent CaO, 8 percent BaO and 5 percent Li.sub.2 O. A shape is then pressed from the mixture; the shape is heated to 450-550 degrees F. for about 30 minutes and cooled to ambient temperature. Silver paint is then applied to the cooled shape and the painted shape is fired to vitrify the frit of the resistor. A lead-free carbon resistor according to the invention eliminates health hazards of human exposure to toxic lead compounds used in many resistors. A preferred resistor according to the invention also maintains an essentially constant resistance over time.

Green ceramic of lead-free glass, conductive carbon, silicone resin and

An improved method for producing a ceramic resistor is disclosed. The method comprises the steps of charging ceramic batch into a longitudinally extending die, pressing the batch in the die between opposing plungers, removing one plunger from the die, ejecting the blank by moving the other plunger relative to the blank and firing the blank. The improvement constitutes imparting rotational motion to the removable plunger as applied pressure thereon is being released to remove the plunger from the die, whereby the surface of the plunger in contact with the blank separates therefrom without sticking.

Production of a ceramic resistor

The present invention provides a novel cellular ceramic catalyst support. The support consists of a random-fiber ceramic framework having a high surface area. The support is fabricated by flocking an organic sponge with wood or textile fibers, and impregnating the flocked sponge with a high alumina slurry containing a silicone resin and a flux. The impregnated organic sponge is sintered at a high temperature to burn out the organic sponge material. A fired high-silica glaze can be applied to the sintered article, followed by a second sintering step. A second glaze containing from 10-25 parts by weight CuO and from 10-25 parts by weight ZrO.sub.2, can be applied, followed by a 2000.degree. F. sintering step. The high temperature causes recrystallization of the CuO onto the surface of the catalyst support thereby increasing the surface area. The glazed surface can be plated with copper or nickel and combinations thereof to function as a reducing unit in a catalytic converter. In addition, other reduction catalysts and oxidation catalysts, e.g., platinum are compatible with the support.

Open mesh, random fiber, ceramic structure, monolithic catalyst support

The present invention relates to a novel aqueous dispersion of a silicone resin and alumina. The dispersion is prepared by mixing 50-90 parts by weight of alumina, 6-45 parts by weight of a phenyl lower alkyl silicone resin and 1/2-6 parts by weight of a flux with from 1/2-7 parts by weight of an alkylolamine detergent in sufficient water to form a dispersion having a viscosity ranging from 300 to 3,000 centipoises.

Aqueous dispersion of ceramic slurry

An improved ceramic article useful after firing as an electrical suppressor element, especially suitable for use in spark plugs, is disclosed. The suppressor element is a copper-aluminum composition modified with a mangesium, calcium, strontium or barium metal compound. The numerical value of the atom ratio of the article,

Modified copper-aluminum suppressor element

An improved ceramic article useful after firing as an electrical suppressor element especially suitable for use in spark plugs is disclosed. The suppressor element is an aluminum-manganese oxide composition modified with a strontium compound which optionally may contain a nickel compound. The numerical value of the atom ratio of the article ##EQU1## IS CONTROLLED FROM 0.1 TO 1.5. The strontium/aluminum atom ratio has a value of from 0.5:1 to 0.95:1. The manganese constitutes from 50 percent to 100 percent based upon the total atoms of manganese and nickel present. The temperature coefficient of resistance of the suppressor, defined by ##EQU2## is between about -2.8%/.degree.C and -1.3%/.degree.C.

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St. Clair Shores, MI, United States of America

Joseph Nemeth