SPARK PLUG CONSTRUCTION

摘要

A spark plug is disclosed and comprises: a metal tube which interiorly defines an axis and is externally-threaded for engine block engagement; an insulator having a portion which is disposed inside the tube and extends therebeyond; a positive electrode extending through the insulator and projecting beyond the extending portion of the insulator; and an annular ground electrode coupled to the tube. The electrodes are configured such that a spark gap defined therebetween comprises an elongate channel which opens axially and away from said insulator and is substantially unobstructed in the axial direction. The ground defines a void having: a central portion occupied by the positive electrode in use; 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

主权项

1. An adapter for use with a spark plug body and an engine block, said spark plug body defining a longitudinal axis and having: adjacent one end, a metal ring which is orientated coaxially with the longitudinal axis; a metal tube which is orientated coaxially with the longitudinal axis, extends from the ring towards the other end of said body and is externally-threaded for engagement in a corresponding threaded bore in said engine block in use; an insulator having a portion disposed inside the tube, which portion extends axially, from inside the tube, beyond the ring, and has an elongate void extending axially therethrough; and an elongate positive electrode which occupies the void and extends axially beyond the insulator to a terminus which defines the one end of said body;
the adapter being secured, in use, to said body, comprising: a positive electrode extender which, in use, is in electrically-conducting contacting relation to the positive electrode; and a ground electrode extender which, in use, is in electrically-conducting contacting relation to the metal ring; and being configured such that a spark gap defined between the positive and ground electrode extenders comprises an elongate channel which opens axially and away from said body and is substantially unobstructed in the axial direction.