GB1051392A - - Google Patents

Abstract

1,051,392. Coated threads. CHAMPION SPARK PLUG CO. April 15, 1965 [May 15, 1964], No. 16395/65. Heading B2K. An engine component having threaded means for engagement with a cooperatively threaded opening of an internal combustion engine has adhered at least to the thread of the threaded means a coating of an organo polysiloxane resin, the resin being crosslinked to such an extent, relative to the average chain length thereof, that the average ratio of organic groups to silicon atoms is from about 1 to 1.6 and it is effective substantially to reduce metalto-metal contact when the threads of the threaded means are engaged in the threaded opening of the internal combustion engine. The component may be a spark discharge device for igniting fuel in a combustion chamber of an internal combustion engine. The resin may be crosslinked through silicon-oxygen-silicon linkages or through the organic groups. The organo groups of the resin may include lower alkyl groups and optionally include some phenyl groups. The resin may be a methyl polysiloxane resin, all the organo groups may be methyl groups; and the resin may contain an average number of 1.15 methyl groups per 'silicon atom. The coating of the polysiloxane resin may be from 0.00001 to 0.00025 inches thick. The resin may be sprayed or painted onto the threaded means, or the means may be dipped into the polysiloxane resin.