| 摘要 |
<p>The shortest distance (F, F') from an end face (11A) of each ground electrode (11, 11') to a porcelain insulator (1) is made smaller than the shortest distance (G, G') from the end face (11A) of each ground electrode (11, 11') to the peripheral side surface of a central electrode (2, 2'). An anti-spark consumption member (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32) is secured to a portion of the central electrode (2, 2') in such a way that it is spaced at least a specified distance (H) of from the end face of the porcelain insulator (1). <IMAGE></p> |
