(under subclass 118) Subject matter in which the whole or a portion thereof is reversible.
(1) Note. This subclass relates, for example, to spark plugs in which the core can be reversed, so that the center electrode tip becomes the binding post and vice versa.
SEE OR SEARCH THIS CLASS, SUBCLASS:
144+, for spark plugs having specific joint structure such as between the insulator and the shell.
236, for other discharge devices which are provided with a stand-by or spare electrode.
