(under subclass 118) Subject matter having significant joint structure.
(1) Note. Where there is a significant joint between the center electrode and core in addition to a joint between other parts, such as the shell and core, subclass 145 must also be searched.
SEE OR SEARCH THIS CLASS, SUBCLASS:
119, for spark plugs which are provided with a joint involving structure so that a part of the plug may be removed from operating position without stopping the engine (e.g., the insulator may be removed from the shell and means are provided to seal off the opening in the shell).
121, where the spark plug is provided with joint structure so that some part (e.g., the insulator) may be removed and replaced in the reverse position.
137, for the subject matter when the insulating core is formed of a plurality of parts. 238+, especially subclasses 243, 267 and 268 for other space discharge devices with supporting and spacing structures which involve joints between the parts.
SEE OR SEARCH CLASS
123, Internal-Combustion Engines,
169, for spark plugs in combination with an internal combustion engine or engine accessory. Included in Class 123 are joints between the spark plug and the cylinder where significant cylinder structure is recited. Also, included in Class 123 is the combination of a spark plug with an adapter designed to hold the plug at one end and designed to be attached to the cylinder at the other end (e.g., to use a small sized plug in a larger sized cylinder opening).
174, Electricity: Conductors and Insulators,
138, for miscellaneous insulated rod joints and subclass 152 for spark plug type electrical bushings (i.e., a spark plug with no ignition sparking electrodes claimed) having joint structure between the parts of the bushing.
285, Pipe Joints or Couplings, appropriate subclasses for mere pipe joints including insulated pipe joints.
403, Joints and Connections, appropriate subclasses for rod joints of general application. Note that insulated rod joints are in Class 174,
138, or one of the classes specified in the notes thereto.
439, Electrical Connectors,
625+, for an electrical connector mounted on or attached to an electrical insulator.
501, Compositions: Ceramic, appropriate subclasses for ceramic compositions or the electric insulating type, such as cements for joints, and for electric insulators defined merely by their composition, especially
127+, and 134+ for clay containing compositions; and subclasses 141+ for titanate and similar material containing compositions.
