Patent ID: 6891318
Filing Date: 2005-05-10
Classification: H01T

Abstract:
1. A spark plug comprising: a first electrode; a second electrode opposed to the first electrode through a given air gap; a noble metal member being in contact of a preselected portion thereof with a preselected portion of at least one of said first and second electrodes, said noble metal member being joined at a contact between said preselected portions with the one of said first and second electrodes by laser welding; and a fused portion that forms a weld between said noble metal member and the one of said first and second electrodes and is made of materials of said noble metal member and the one of said first and second electrodes fused together by the laser welding, said fused portion continuing over at least half a circumferential direction of the contact between said preselected portions of said noble metal member and the one of said first and second electrodes without interfaces of welds.