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 sealing ring for a spark plug that has an external thread for screwing into an internal combustion engine, a collar and a thread undercut between the external thread and the collar. The sealing ring includes a ring-shaped solid sealing element made from metal. The sealing element has two planar annular sealing surfaces that are arranged parallel to one another. An annular retaining element composed of an elastomer for engaging in the thread undercut of the spark plug in a self-retaining manner is attached to the sealing element on the inner ring side thereof. Also included is a spark plug comprising such a sealing ring, and an internal combustion engine comprising such spark plugs.

A sealing ring for a spark plug that has an external thread for screwing into an internal combustion engine, a collar and a thread undercut between the external thread and the collar. The sealing ring includes a ring-shaped solid sealing element made from metal. The sealing element has two planar annular sealing surfaces that are arranged parallel to one another. An annular retaining element composed of an elastomer for engaging in the thread undercut of the spark plug in a self-retaining manner is attached to the sealing element on the inner ring side thereof. Also included is a spark plug comprising such a sealing ring, and an internal combustion engine comprising such spark plugs.

A spark plug having an insulating body defining a longitudinal axis and including a base portion and an obstruction portion, a first electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the first electrode extending through the base portion of the insulating body, and a second electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the second electrode extending through the base portion and the obstruction portion of the insulating body, wherein the obstruction portion axially extends beyond the distal portion of the first electrode.

A spark plug having a spark plug body and an insulator arranged therein, in which insulator a passage is provided in which a center electrode, an ignitor and a glass seal connecting the center electrode to the ignitor and acting as an interference-suppression resistor are arranged. At least one additional interference-suppression element is arranged in the passage of the insulator.

One example provides a spark plug including an axial centerline extending between a terminal end and a firing end, an insulative core including a central bore having a first diameter coincident with the axial centerline extending through the insulative core, an insulative nose proximate to the firing end, and a counter bore coincident with the axial centerline and extending axially into the insulative nose, the counter bore having a second diameter greater than the first diameter. A center electrode includes an electrode wire disposed within the central bore and having a first end extending into the counter bore, and an electrode head mechanically and electrically coupled to the first end of the electrode wire, a first portion of the electrode head seated within the counter bore to define an interface with the counter bore to provide a heat transfer path from the electrode head to the insulative core.

One example provides a spark plug including an axial centerline extending between a terminal end and a firing end, an insulative core including a central bore having a first diameter coincident with the axial centerline extending through the insulative core, an insulative nose proximate to the firing end, and a counter bore coincident with the axial centerline and extending axially into the insulative nose, the counter bore having a second diameter greater than the first diameter. A center electrode includes an electrode wire disposed within the central bore and having a first end extending into the counter bore, and an electrode head mechanically and electrically coupled to the first end of the electrode wire, a first portion of the electrode head seated within the counter bore to define an interface with the counter bore to provide a heat transfer path from the electrode head to the insulative core.

A housing for a spark plug. The housing includes a bore along the longitudinal axis X of the housing, as the result of which the housing has an outer side and an inner side, and an electroplated or chemically applied nickel-containing protective layer situated on at least one portion of the outer side of the housing and a sealing layer situated on the nickel-containing protective layer. The sealing layer contains silicon. A first intermediate layer is applied between the housing and the nickel-containing protective layer and/or a second intermediate layer is applied between the nickel-containing protective layer and the sealing layer and/or a cover layer is applied on the sealing layer. The sealing layer may be free of chromium.

A housing for a spark plug. The housing includes a bore along the longitudinal axis X of the housing, as the result of which the housing has an outer side and an inner side, and an electroplated or chemically applied nickel-containing protective layer situated on at least one portion of the outer side of the housing and a sealing layer situated on the nickel-containing protective layer. The sealing layer contains silicon. A first intermediate layer is applied between the housing and the nickel-containing protective layer and/or a second intermediate layer is applied between the nickel-containing protective layer and the sealing layer and/or a cover layer is applied on the sealing layer. The sealing layer may be free of chromium.