RFI suppression spark plug

Claim 2

A spark plug for suppressing radio frequency interference and having particular application utility in an ignition system of the capacitor-discharge type, said spark plug comprising; an outer body, an insulator attached to said body and a center electrode assembly disposed within said insulator, said center electrode assembly including in electrical series therewith an inductor element having a minimum resistance, said inductor element being of wound wire having relatively high electrical conductivity and substantially enclosed within said insulator.

Claim 3

The device of claim 1 wherein said inductor element is wire wound upon a core of high dielectric strength.

Claim 4

The device of claim 2 further including a compression spring to maintain said inductor element in electrical contact within said center electrode assembly.

Claim 5

The device of claim 2 wherein said wire wound inductor element has an inductance of from 10 to 100 microhenries.

Claim 6

The device of claim 4 wherein said wire wound inductor element has a resistance of less than 1,000 ohms.

Claim 7

A radio frequency interference suppressing spark plug including an outer body comprising the ground electrode of the plug, an insulator retained within said outer body, a center electrode disposed within said insulator and together with said outer body forming the spark gap of the spark plug characterized by an inductor encased within said insulator and in electrical series with said center electrode, said inductor preferably having an inductance of 10 to 50 microhenries and a resistance of less than 100 ohms.

Claim 8

A radio frequency interference suppressing spark plug including an outer body comprising the ground electrode of the plug, an insulator retained within said outer body, a center electrode disposed within said insulator and together with said outer body forming the spark gap of the spark plug characterized by an inductor encased within said insulator and in electrical series with said center electrode, said inductor preferably having an inductance of 10 to 50 microhenries and a resistance of less than 100 ohms.

Claim 9

A spark plug comprising; an outer metallic body comprising an annular ground electrode, an insulating sleeve extending within and attached to said outer body, a center electrode disposed within said insulating sleeve and with said annular ground electrode forming an annular spark gap, and, a wire wound inductor also disposed within said insulating sleeve and in electrical series with said center electrode, said inductor element being of wound wire having relatively high electrical conductivity and capable of substantially suppressing radio frequency interference generating oscillations Initiated by the firing of the spark plug without adversely affecting the performance of the engine in which it is operating.

Claim 10

A spark plug comprising; an outer metallic body comprising an annular ground electrode, an insulating sleeve extending within and attached to said outer body, a center electrode disposed within said insulating sleeve and with said annular ground electrode forming an annular spark gap, and, a wire wound inductor also disposed within said insulating sleeve and in electrical series with said center electrode, said inductor element being of wound wire having relatively high electrical conductivity and capable of substantially suppressing radio frequency interference generating oscillations Initiated by the firing of the spark plug without adversely affecting the performance of the engine in which it is operating.

Claim 11

The spark plug of claim 7 wherein said inductor element comprises a single layer coil winding having a diameter substantially equal to the largest diameter of said center electrode.

Claim 12

The device of claim 1, in which said inductor element has a resistance of less than 50 ohms.

Claim 13

In a spark-plug construction for suppressing radio-frequency interference, said construction comprising an outer body, a center electrode within said insulator, and an external terminal carried by said insulator for application of excitation voltage to said electrode, the improvement which comprises a coiled-wire inductance establishing the electrical series connection of said electrode to said terminal, said inductance being substantially contained within said insulator and of wire having relatively high electrical conductivity and therefore minimum resistance.

Claim 14

In a spark-plug construction for suppressing radio-frequency interference, said construction comprising an outer body, a center electrode within said insulator, and an external terminal carried by said insulator for application of excitation voltage to said electrode, the improvement which comprises a coiled-wire inductance establishing the electrical series connection of said electrode to said terminal, said inductance being substantially contained within said insulator and of wire having relatively high electrical conductivity and therefore minimum resistance.