Patent ID: 7808165
Filing Date: 2010-10-05
Classification: H01T

Abstract:
1. A spark plug for a spark-ignited internal combustion engine, said spark plug comprising: a generally tubular ceramic insulator; a conductive shell surrounding at least a portion of said ceramic insulator, said shell including at least one ground electrode; a center electrode disposed in said ceramic insulator, said center electrode having an upper terminal end and a lower sparking end in opposing relation to said ground electrode with a spark gap defining the space therebetween; said ground electrode extending from an anchored end adjacent said shell to a distal end adjacent said spark gap, said ground electrode including a ledge formed on said distal end, said ledge having at least one inset planar surface; a sparking tip located on said distal end of said ground electrode, said sparking tip having a base end attached to said inset planar surface of said ledge and a side peripheral surface extending from said base end; said inset planar surface intersecting said distal end of said ground electrode and completely covering said base end of said sparking tip, said inset planar surface being oversized in area relative to said base end so as to extend outwardly therefrom to provide an exposed peripheral interface portion of said inset planar surface adjacent said base end; said ledge further including an inset back wall spaced from said distal end and intersecting said planar surface, said peripheral surface of said sparking tip directly abutting said back wall of said ledge; and at least one weld bonding said base end of said sparking tip to said inset planar surface, and at least one weld bonding said peripheral surface of said sparking tip to said back wall of said ledge.