Ignition Device Having an Electrode With a Platinum Firing Tip and Method of Construction

An electrode assembly for an ignition device, comprising:

• an electrode body having an outer surface;
• a firing tip having a lower surface and an outer periphery;
• a resistance weld joint bonding said firing tip lower surface to said electrode body, said lower surface being embedded a first distance beneath said outer surface;
• and
• a continuous bead of overlapping laser weld pools formed over said firing tip outer periphery, said laser weld pools extending a second distance beneath said electrode body outer surface, said second distance being greater than said first distance.

A method of construction for an ignition device, comprising:

• providing an electrode body having an outer surface;
• providing a preformed piece of noble metal firing tip material;
• resistance welding said firing tip material to said body to at least partially form a firing tip and defining a lower surface of said firing tip a first distance beneath said outer surface;
• and
• laser welding a continuous bead of overlapping laser weld pools over an outer periphery of said firing tip so that said weld pools extending a second distance beneath said outer surface, wherein said second distance is greater than said first distance.

A method of constructing an ignition device for an internal combustion engine, comprising:

• providing a housing;
• securing an insulator within the housing with an end of the insulator exposed through an opening in the housing;
• mounting a center electrode body having an outer surface within the insulator with a firing tip region of the center electrode body extending beyond the insulator;
• extending a ground electrode body having an outer surface from the housing with a firing tip region of the ground electrode body being located opposite the firing tip region of the center electrode body to define a spark gap therebetween;
• providing at least one preformed piece of firing tip material formed from noble metal;
• resistance welding said at least one piece of firing tip material to at least one of said center electrode body or said ground electrode body to at least partially form a firing tip and defining a lower surface of said firing tip a first distance beneath said outer surface;
• and
• laser welding a continuous bead of overlapping laser weld pools over an outer periphery of said firing tip so that said weld pools extending a second distance beneath said outer surface, wherein said second distance is greater than said first distance.