Patent ID: 6589091
Filing Date: 2003-07-08
Classification: H01T

Abstract:
A fabricating method of fabricating a spark plug with at least two ground electrodes which are bent to an L-shape to have ends facing through spark gaps a center electrode installed in a housing, the fabricating method comprising the steps of:welding at least two electrode bars to the housing of the spark plug at a given interval away from each other; placing a first die at a location where the center electrode is to be installed between the electrode bars, the die having curves each contoured to conform with the L-shape of the ground electrodes; moving a second die to urge one of the electrode bars into contact of an inner surface thereof with said first die; pushing said second die to press the one of the electrode bars against a corresponding one of the curves of the first die, thereby bending the one of the electrode bars to fabricate one of the ground electrodes of the L-shape; moving a third die to urge the other electrode bar into contact of an inner surface thereof with said first die; and pushing said third die to press the other electrode bar against the other curve of the first die, thereby bending the other electrode bar to fabricate the other ground electrode of the L-shape.