Abstract: A spark plug for an internal combustion engine comprises an elongated center electrode having a center electrode tip at one end and a terminal proximate the other end, an insulator substantially surrounding the center electrode, and a ground shield. The insulator has a substantially cylindrical body with at least a first insulator section and a second insulator section. The first and second insulator sections having first and second diameters respectively and are separated by an insulator shoulder. The ground shield has an elongated base section substantially surrounding the first insulator section, a frustoconical flange protruding from one end of the base section to engage the insulator shoulder, and a ground electrode extending from the other end of the base section to define an axial spark gap with respect to the center electrode tip. The base section and the ground electrode are formed as separate components and secured together to form the ground shield.

Abstract: A small diameter spark plug configuration is provided, the configuration has been found to provide additional volume for the insulator member. That is, by limiting the overall number of threads on the intermediate portion along with a limit of the overall diameter of the spark plug, additional volume of insulator material may be achieved in an interior cavity of a metal shell of the spark plug. This additional volume enables a portion of the insulator member to have a larger diameter and hence greater material thickness. The larger diameter of the insulator provides enhanced dielectric properties and protects internal components of the spark plug from high combustion chamber temperatures while simultaneously providing a robust attachment of the spark plug with an engine head.

Abstract: A spark plug is provided providing resistance to fouling. The spark plug includes a metal shell having a first end, a second end and an intermediate portion that collectively define a central cavity. The spark plug also includes an insulator that extends through the central cavity of the metal shell. The insulator includes a first end portion extending through an intermediate portion to a stepped tip portion having a first length. The stepped tip portion includes a first section and a substantially straight second section having a second length. The substantially straight second section includes a segment that extends beyond the second end of the metal shell to a third length. The second length of substantially straight portion is based upon at least one of the first length and the third length.

Abstract: A spark plug casing includes a single-piece shell having a nut portion, first and second tubular portions and a converging shell portion, which are configured to be removed from a cylinder head as an integral device. The first tubular portion extends from the nut portion and has a first cross-sectional size. The second tubular portion has a second cross-sectional size less than the first cross-sectional size. The converging shell portion is coupled between the first and second tubular portions. The casing further includes a ground strap having a third cross-sectional size less than the second cross-sectional size. The ground strap is received within an end portion of the second tubular portion opposite the converging shell portion, such that the ground strap and the cylinder head are in a spaced relationship with respect to each other for preventing carbon buildup from binding the ground strap to the cylinder head.

Abstract: Exemplary embodiments of the present invention provide a spark plug for use in conjunction with an internal combustion engine, and, more particularly, to a spark plug having a structure providing improved ignition capability. In one particular configuration, a spark plug is provided forming a gap between a center electrode and an insulator of the spark plug. However, it will become apparent that other configurations are contemplated as well, as shown and described herein.

Abstract: An igniter for an internal combustion engine, the igniter comprising: a center electrode; an insulator disposed about the center electrode; a ground shield disposed about the insulator, the insulator having a tip portion extending past an end portion of the ground shield and a tip portion of the center electrode extending through and away from the tip portion of the insulator; and a spark gap disposed between the tip portion of the center electrode and the end portion of the ground shield.

Abstract: A spark plug having a center electrode with a cylindrical body with a tip at one end and a terminal near the other end with an insulator radially surrounding the center electrode. A ground shield surrounds the insulator and includes a ground electrode near one end, having a portion thereof with an annular opening disposed above and radially separated from the center electrode tip to form a radial spark gap, with a sealing portion disposed between the ground electrode and the other end of the ground shield for sealing the engine combustion chamber from the outside environment when the spark plug is installed. The ground shield can be formed from two parts which are deformed during manufacturing to be in mechanical engagement and securely holding the insulator in place. The spark plug can also have also have an integral or separate retainer for securing the spark plug to the engine.

Abstract: A spark plug (80) having a center electrode (82) with a cylindrical body and having a tip (84) at one end and a terminal (123) near the other end with an insulator (86) extending around the center electrode (82). A ground shield and retainer unit extends around the insulator (86) and includes a threaded portion (88) near one end and a ground electrode (85) near the other end, having a portion thereof aligned with the center electrode tip (84) to form a spark gap, with a sealing portion (92) disposed therebetween for sealing the engine combustion chamber from the outside environment when the spark plug (80) is installed. The ground shield and retainer unit can be formed from two parts (88,90) which are deformed during manufacturing to be in mechanical engagement and securely holding the insulator (86) in place. The spark plug (80) can also have two or more center electrodes (82,84) with two or more corresponding ground electrodes (83,85) projecting from the ground shield (90).

Abstract: A spark plug (11) having a center conductive path (21) with a cylindrical body having a tip (33, 51, 77) at one end and a terminal (23) near the other end has an insulator (41, 45) radially surrounding the center electrode and a substantially cylindrical body with at least first and second diameter sections separated by a shoulder (29). A ground shield (37) surrounds the insulator first diameter section and including near one end a frustoconical section (31) juxtaposed with the insulator shoulder. There is a ground electrode (55, 57, 73) near the other end having a portion thereof (53, 75) aligned with the center electrode tip to form a spark gap. An annular retainer (59) surrounds the insulator second diameter section and including a threaded portion (61) threadedly engaging the threaded portion (17) of a generally cylindrical opening in the head of an internal combustion engine.

Abstract: A spark plug for use in an internal combustion engine having a insulator with a cylindrical body that surrounds a center electrode. The cylindrical body has a first diameter section separated from a second diameter section by a shoulder. A sleeve that surrounds the second diameter has an integral base that is positioned a fixed distance from the tip of the center electrode by the engagement of a flange on the sleeve with shoulder on the cylindrical body. A radial tab that extends from the sleeve is located in a slot in a head on a combustion chamber of an internal combustion engine to establish the position of a ground electrode defined by the base in the combustion chamber. An end nut that surrounds the first diameter and engages the flange to locate and position the spark plug within the combustion chamber.