Patent ID: 7923909
Filing Date: 2011-04-12
Classification: H01T

Abstract:
1. An ignition device for an internal combustion engine, comprising: a housing having an opening; an insulator secured within the housing with an end of the insulator exposed through said opening in the housing; a center electrode mounted within the insulator and having a free end extending beyond the insulator; a ground electrode extending from the housing with a portion of the ground electrode being located opposite the free end of the center electrode to define a spark gap therebetween; at least a selected one of said center electrode or ground electrode having a platinum-based firing tip; a resistance weld joint bonding said firing tip to said selected electrode, said resistance weld joint defining a lower surface of said firing tip embedded a first distance beneath an outer surface of said selected electrode; and a continuous bead of overlapping laser weld pools formed over an outer periphery of said firing tip further bonding said firing tip to said selected electrode, said overlapping weld pools extending a second distance beneath said outer surface of said selected electrode, wherein said second distance is greater than said first distance and said firing tip is free from undercuts from said laser weld pools.