Patent ID: 7011560

Claim:
A method of constructing a ground electrode ( 14 , 114 ) for a spark plug ( 10 ) comprising the steps of: providing a segment of metal wire having an upper surface ( 38 , 138 ) and a lower surface ( 40 , 140 ); forming a through hole ( 20 , 120 ) in the wire, said through hole ( 20 , 120 ) extending between and opening to each of said upper ( 38 , 138 ) and lower ( 40 , 140 ) surfaces; providing a firing tip ( 18 , 118 ) having a longitudinal axis; inserting the firing tip ( 18 , 118 ) within the through hole ( 20 ); and compressing the firing tip ( 18 , 118 ) in the direction of its longitudinal axis such that a first end ( 46 , 146 ) of the firing tip ( 18 , 118 ) flares outwardly from the longitudinal axis and a bulging portion ( 51 , 151 ) is formed inside the through hole ( 20 , 120 ) between the upper ( 38 , 138 ) and lower ( 40 , 140 ) surfaces of the wire.