Patent ID: 8272909

Claim:
A method of assembling a spark plug comprising the steps of: providing a generally tubular insulator having an upper terminal end and a lower nose end, and a central passage extending longitudinally between the terminal and nose ends; inserting a center electrode into the central passage of the insulator such that a lower sparking end of the center electrode is exposed through the nose end, the center electrode further including an electrode head seated in the central passage; filling the central passage with loose granular or pelletized sealing materials; compressing the loose sealing materials against the electrode head; heating the insulator, center electrode and loose sealing materials to a temperature at which the loose sealing materials become fluidic and begin to coalesce; inserting an intermediate connecting pin into the central passage, the connecting pin having a lower shank portion; displacing the coalescing sealing materials with the shank of the connecting pin; and holding a tapered head of the connecting pin against an intermediate tapered section in the central passage, generally midway between the terminal end and the electrode head at least until the sealing materials begin to solidify into an elastic solid.