SPARK PLUG

摘要

The plug comprises a nut, a coupling extending from the nut and adapted to receive an ignition wire and an insulator extending from the nut and away from the coupling. A positive electrode extends through the insulator. An externally-threaded tubular portion extends from the nut in surrounding relation to the insulator and terminating, short of the insulator end, in a cap that is disposed in spaced relation to the insulator. The cap defines a void having: a central portion into which the positive electrode extends; an annular channel surrounding the central portion; and a plurality of lobes, each positioned with respect to the central portion as the planet gears are positioned with respect to the sun gear in a planetary gear. The cap has a central surface that is axially spaced from the insulator and a convex surface that surrounds and extends to the central surface.

主权项

1. A spark plug for use with an engine block/cylinder head having a threaded bore and also for use with a spark plug wrench and an ignition wire, the plug comprising:
a nut portion adapted to be turned by the wrench; a coupling portion extending from the nut portion and adapted to receive the ignition wire; an insulator portion extending from the nut portion and away from the coupling portion to an end; a positive electrode extending through and beyond the end of the insulator portion; and a ground electrode including
a tubular metal portion extending from the nut portion in surrounding relation to the insulator portion, the tubular portion being orientated coaxially about and defining a longitudinal axis and further being externally-threaded for engagement in the threaded bore in said engine block in use; anda cap portion to which the metal portion extends and disposed in spaced relation to the insulator portion, the cap portion
defining a void having: a central portion into which the positive electrode extends; an annular channel surrounding the central portion; and a plurality of lobes, each being positioned with respect to the central portion in a manner analogous to the placement of the planet gears with respect to the sun gear in a planetary gear.having: a central surface axially spaced from that portion of the insulator that protrudes beyond the tubular portion; and a convex surface that surrounds and extends to the central surface.