Patent ID: 9478946
Filing Date: 2016-10-25
CPC Classification: H01T

Claim Text:
1. A spark plug for use with an engine block/cylinder head, said spark plug comprising: a metal tube which is orientated coaxially about and defines a longitudinal axis 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 beyond the tube; a rod-like shaped positive electrode extending through the insulator and projecting beyond the portion of the insulator that extends beyond the tube; a ground electrode coupled to the metal tube, the ground electrode is annular and defines a void having: a central portion which is occupied by the positive electrode in use; an annular 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, the lobes being equally spaced around a circumference of the round electrode; and wherein the positive and ground electrodes are configured such that a spark gap defined between the positive and ground electrodes includes an elongate channel which opens axially and away from said insulator and is substantially unobstructed in the axial direction.