Patent ID: 6362562
Filing Date: 2002-03-26
Classification: H01T

Abstract:
A spark plug comprising:(a) a spark plug housing defining a longitudinal axis extending from a first end of the housing to a second opposing end of the housing; (b) a center electrode disposed along the longitudinal axis of the housing and defining a first spark propagation surface at its free end, the free end being proximate the first end of the housing, and the first spark propagation surface extending a distance parallel to the longitudinal axis of the center electrode towards the second end of the housing; (c) a ground electrode defining a second spark propagation surface proximate the first end of the housing, the second spark propagation surface being parallel to and radially spaced from the first spark propagation surface of the center electrode, and extending a distance parallel to the longitudinal axis of ground electrode towards the second end of the housing; and (d) the first and second spark propagation surfaces defining parallel, opposing and longitudinally extending surface areas between which sparks may continue to propagate as the free end of the center electrode wears from use; (e) a plurality of parallel sharp edges formed in the longitudinally extending surface area of one of the spark propagation surfaces, each of the sharp edges lying in a plane oblique to the longitudinal axis of the spark plug housing, and the plurality of sharp edges providing a series of breaks along the surface of the electrode in which they are formed to continuously facilitate the propagation of sparks as the center electrode wears from use.