(under subclass 118) Subject matter having the insulating core formed of a plurality of parts.
(1) Note. For the purpose of classification in this subclass, stacked parallel laminations of mica will not be considered to be plural members, but mica members whose planes are not parallel (as, for example, a rolled mica tube surrounded by flat mica washers) are considered to be plural members. A thin cement layer which is utilized to adhere together parts of the spark plug or to make joints gas tight is not considered to be an insulating member even though it may, in fact, be an insulator.
(2) Note. The different parts of the core may be cemented together or may be held together by mechanical means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
130+, for spark plugs having an insulating member in or closely adjacent to the spark gap.
SEE OR SEARCH CLASS
174, Electricity: Conductors and Insulators, 152+, for insulated bushings, including spark plug type bushings (i.e., not having claimed ignition spark electrodes).
