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.

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.

A spark plug is provided that ensures that a ground electrode is positioned in a predefined, precise orientation when installed in a spark plug hole of an engine head. The spark plug is configured for axial insertion into the plug hole, and has a non-axisymmetric ground shield that fits into the plug hole, wherein the ground shield has an outer shield surface with a non-axisymmetric shape and 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 spark plug includes a jamb nut which is rotatable to fix the spark plug in position in a predefined orientation. Preferably, an outer surface of the insulator and an inner surface of the ground shield have complementary shapes wherein the ground shield fits closely on the insulator. For example, the outer insulator surface and the inner shield surface may have a complementary axisymmetric shape, such as cylindrical, or a non-axisymmetric shape, which may conform to the non-axisymmetric shape of the outer shield surface.

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.

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.

A spark plug is provided that ensures that a ground electrode is positioned in a predefined, precise orientation when installed in a spark plug hole of an engine head. The spark plug is configured for axial insertion into the plug hole, and has a non-axisymmetric ground shield that fits into the plug hole, wherein the ground shield has an outer shield surface with a non-axisymmetric shape and 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 spark plug includes a jamb nut which is rotatable to fix the spark plug in position in a predefined orientation. Preferably, an outer surface of the insulator and an inner surface of the ground shield have complementary shapes wherein the ground shield fits closely on the insulator. For example, the outer insulator surface and the inner shield surface may have a complementary axisymmetric shape, such as cylindrical, or a non-axisymmetric shape, which may conform to the non-axisymmetric shape of the outer shield surface.

A spark plug assembly is provided with an insulator body extending along a longitudinal axis and defining a first face extending radially and positioned between the first and second ends. A central electrode extends through the insulator body, and a side electrode is connected to the insulator body for rotation therewith. A retainer is connected to the second end of the insulator body and defines a second face extending radially. A jacket is rotatably supported by and surrounds the insulator body. The jacket is positioned between the first and second faces, and defines an inner surface and a threaded outer surface. A bushing is rotatably supported by and surrounds the insulator body, is positioned radially between the jacket and the insulator body, and is positioned between the first and second faces. The bushing defines a tapered outer surface to mate with the inner surface of the jacket.

A spark plug assembly is provided with an insulator body extending along a longitudinal axis and defining a first face extending radially and positioned between the first and second ends. A central electrode extends through the insulator body, and a side electrode is connected to the insulator body for rotation therewith. A retainer is connected to the second end of the insulator body and defines a second face extending radially. A jacket is rotatably supported by and surrounds the insulator body. The jacket is positioned between the first and second faces, and defines an inner surface and a threaded outer surface. A bushing is rotatably supported by and surrounds the insulator body, is positioned radially between the jacket and the insulator body, and is positioned between the first and second faces. The bushing defines a tapered outer surface to mate with the inner surface of the jacket.

In this disclosure the inventor is disclosing his Fulcrum Spark Plug for combustion engine; when the latch is on, the handle will not turn but with a thread allowance and a clock wise turn of the handle will automatically lower the latch so that the handle can turn where all corners of the triangle shape plug are in line with the shaft the plug can be manually raised.

In this disclosure the inventor is disclosing his Fulcrum Spark Plug for combustion engine; when the latch is on, the handle will not turn but with a thread allowance and a clock wise turn of the handle will automatically lower the latch so that the handle can turn where all corners of the triangle shape plug are in line with the shaft the plug can be manually raised.