(under subclass 118) Subject matter having an ignition electrode whose shape is that of a ball or a substantial portion of a ball.
(1) Note. This subclass relates, for example, to spark plugs in which one electrode is a substantially hemispherical or hemispheroidal surface formed of a thin sheet material.
SEE OR SEARCH THIS CLASS, SUBCLASS:
325, and the subclasses specified in the notes thereto for other discharge devices having ball electrodes, and subclass 326 for the electrodes, per se.
