US 11,258,235 B2 · High thread jamb nut with retaining clip

Abstract

A spark plug is provided that includes an improved jamb nut configuration, which provides improved torque transfer and prevents inadvertent separation of the jamb nut from the remaining components of the spark plug, particularly during removal from the engine head. The spark plug is configured for axial insertion into the plug hole, and may have a non-axisymmetric ground shield that fits into the plug hole, wherein the plug hole is also provided with a complementary non-axisymmetric shape. The spark plug includes a central insulator, which has an inner end surrounding a central electrode and supporting the ground shield, which is mounted on the insulator to support a ground strap adjacent the electrode for forming a spark therebetween. The insulator and ground shield are axially slidable into the plug hole, and the jamb nut is rotatable to fix the spark plug in position in a predefined orientation. The insulator includes a retaining clip outwardly of the jamb nut that permits rotation of the jamb nut relative to the insulator but prevents axial separation of the jamb nut during removal of the spark plug from the engine head. An improved tool is also provided which better distributes torque transfer to the jamb nut and includes a catch to facilitate pulling of the spark plug from the engine head.

Claims20

Dependent claims

A spark plug for an internal combustion engine, the spark plug comprising:

an elongated center electrode having a center electrode tip at a first end and a terminal proximate a second, opposite end;
an insulator substantially surrounding the center electrode;
a ground shield surrounding a portion of the insulator proximate said center electrode tip in spaced relation to define a spark gap therebetween, a shell substantially surrounding the insulator and defining a drive shoulder at one end and a seating shoulder at an opposite end proximate said ground shield for seating engagement with a spark plug hole of an engine head;
a jamb nut rotatably supported on said insulator axially outwardly of said drive shoulder, said jamb nut having a first end portion comprising a threaded portion proximate said shell for threaded engagement with said plug hole, said jamb nut being rotatable relative to said insulator and said first end portion terminating at a drive rim which axially contacts said drive shoulder of said shell to axially drive said spark plug into said plug hole, said jamb nut having a second end portion opposite said first end portion which includes a drive collar for rotatable driving by a tool;
and a retaining member fixed on said insulator adjacent said second end portion of said jamb nut to prevent axial separation of said jamb nut from said insulator during spark plug removal from said plug hole.

2 more elements

A spark plug for an internal combustion engine, the spark plug comprising:

an elongated center electrode having a center electrode tip at a first end and a terminal proximate a second, opposite end;
an insulator substantially surrounding the center electrode and defining an enlarged intermediate section defined by first and second insulator shoulders;
a ground shield surrounding a portion of the insulator proximate said center electrode tip in spaced relation to define a spark gap therebetween, a shell substantially surrounding the insulator and defining a drive shoulder at one end and a seating shoulder at an opposite end proximate said ground shield for seating engagement with a spark plug hole of an engine head, said drive shoulder and said seating shoulder abutting against said first and second insulator shoulders to prevent axial displacement of said shell along said insulator;
a jamb nut rotatably supported on said insulator axially outwardly of said drive shoulder, said jamb nut having a first end portion comprising a threaded portion proximate said shell for threaded engagement with said plug hole where reversing rotation of said jamb nut moves said spark plug into and out of said plug hole, said jamb nut being rotatable relative to said insulator and said shell, and said first end portion terminating at a drive rim which axially contacts said drive shoulder of said shell to axially drive said spark plug into said plug hole during rotation of said jamb nut in a first rotation direction during spark plug installation, said jamb nut having a second end portion opposite said first end portion which includes a drive collar for rotatable driving by a tool in said first rotation direction and an opposite second rotation direction;
and a retaining member fixed on said insulator adjacent said second end portion of said jamb nut to prevent axial separation of said jamb nut from said insulator during rotation of said jamb nut in said second rotation direction during spark plug removal.

2 more elements

Dependencies are inferred from the claim text.

High thread jamb nut with retaining clip

Life of this patent

High thread jamb nut with retaining clip

Life of this patent

Abstract

Claims20