Conductivity path for non-conductive tire tread

A pneumatic tire, comprising:

• a tread cap rubber defining the tread of the tire, said tread cap rubber comprised of an electrically conductive rubber material;
• a tread base rubber disposed radially inside the tread cap rubber, said tread base rubber comprised of an electrically insulating rubber;
• a pair of nonconductive sidewall portions;
• a pair of bead bundles;
• a carcass extending between said pair of bead bundles and being wrapped around each said bead bundle;
• a belt cushion section disposed radially outside the carcass, said belt cushion section comprised of outer insulating portions separated circumferentially by an inner conducting portion;
• and
• at least one belt layer disposed radially outside of said belt cushion section but radially inward from said tread base rubber;
• wherein said tread cap rubber also defines a conducting bridge extending radially inward from said tread cap rubber, through said tread base rubber, so as to provide an electrically conductive path to said at least one belt layer.

A pneumatic tire, comprising:

• a tread cap rubber defining the tread of the tire, said tread cap rubber comprised of an electrically conductive rubber material;
• a tread base rubber disposed radially inside the tread cap rubber, said tread base rubber comprised of an electrically insulating rubber;
• a pair of nonconductive sidewall portions;
• a pair of bead bundles;
• a carcass section extending between said pair of bead bundles and being wrapped around each said bead bundle;
• a belt cushion section disposed radially outside the carcass section;
• at least one belt layer disposed radially outside of said belt cushion section but radially inward from said tread base rubber section;
• and
• wherein said tread cap rubber also defines a first conducting path extending radially inward from said tread cap rubber, through said tread base rubber, so as to provide for the conduction of electricity between said tread cap rubber and said at least one belt layer.

A method of manufacturing a pneumatic tire, comprising:

• providing a carcass section of a first electrically conductive material extending between a pair of bead bundles, the carcass section wrapping around each bead bundle;
• overlaying a belt cushion section of electrically insulating material onto the carcass section;
• forming a series of apertures spaced circumferentially along the belt cushion section;
• providing at least one belt layer of a second electrically conductive material disposed onto the belt cushion section radially outside of the belt cushion section,
• extruding a tread section, the tread section comprising (i) a tread cap rubber defining the tread of the tire and being constructed from an electrically conductive rubber material and (ii) a tread base rubber located radially inside the tread cap rubber, wherein the tread cap rubber also defines a first conducting path extending through the tread base rubber;
• applying the tread section onto the at least one belt layer to form an intermediate tire wherein the first conducting path is electrically connected to the at least one belt layer;
• and subjecting the intermediate tire to heat and pressure so as to cause the first and second electrically conductive materials from the carcass section and the at least one belt layer to migrate into the series of apertures and connect so as to provide a second conducting path between the carcass section and the at least one belt layer.