High electrical stiction spark plug

A spark plug comprising:

• an elongated electrical insulator body defining a first bore extending longitudinally along a central axis of the body from a connector end to a firing end;
• a sparking electrode communicating with the first bore, the sparking electrode including a firing tip defining a convex outer surface generally having a radius of curvature, the firing tip having an outermost point generally coinciding with the central axis;
• and
• a ground electrode including a sleeve adjacent to the firing tip of the sparking electrode, the sleeve defining a second bore accommodating at least a longitudinal end portion of the insulator body adjacent to the firing end, the ground electrode further including an elongated member extending outwardly from the sleeve, the elongated member including two support portions disposed at radially opposite ends of the sleeve relative to each other and extending generally outwardly from the sleeve toward the firing end, and the elongated member including a generally rectangularly shaped bridge portion extending between the support portions, the bridge portion having an inner surface extending between an upper surface and a lower surface of the bridge portion of the inner surface defining a generally circular hole, the inner surface forming a circle disposed generally in a plane transverse to and having a radial center coinciding with the central axis of the insulator body, whereby each differential segment of the inner surface radially thereabout is generally equidistant to the firing tip, the inner surface being a closest portion of the ground electrode relative to the firing tip, and at least a portion of the inner surface of the bridge portion opposing the firing tip having a radius of curvature of about that of the firing tip for providing a spark along a path of least resistance train the firing tip of the sparking electrode to a point of contact on the opposing inner surface defined by the bridge portion.

A spark plug comprising:

• an elongated electrical insulator body defining a first bore extending longitudinally along a central axis of the body from a connector end to a firing end;
• a sparking electrode communicating with the first bore, the sparking electrode including a firing tip defining a convex outer surface generally having a radius of curvature, the firing tip having an outermost point generally coinciding with the central axis;
• and
• a ground electrode including:
• a sleeve adjacent to the firing tip of the sparking electrode, the sleeve defining a second bore accommodating at least a longitudinal end portion of the insulator body adjacent to the firing end;
• an elongated member extending outwardly from the sleeve, the elongated member including two support portions disposed at radially opposite ends relative to each other and extending generally outwardly from the sleeve toward the firing end;
• a generally rectangularly shaped bridge portion extending between the support portions, the bridge portion having an inner surface extending between an upper surface and a lower surface of the bridge portion, the inner surface defining a generally circular hole, the inner surface forming a circle disposed generally in a plane transverse to and having a radial center coinciding with the central axis of the insulator body, whereby each differential segment of the inner surface radially thereabout is generally equidistant to the firing tip, the inner surface being a closest portion of the ground electrode relative to the firing tip, and at least a portion of the inner surface of the bridge portion opposing the firing tip having a radius of curvature of about that of the firing tip for providing a spark along a path of least resistance from the firing tip of the sparking electrode to a point of contact on the opposing inner surface defined by the bridge portion;
• and
• a cylindrical member disposed between the sleeve and the elongated member.