Patent ID: 6752188
Filing Date: 2004-06-22
Classification: B29D,B60C,Y10T

Abstract:
A pneumatic tire comprisinga tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, a carcass comprising a carcass ply extending between the bead portions and turned up around the bead core in each bead portion to form two turnup portions and a main portion therebetween, each said turnup portion extending radially outwardly and adjoining the main portion from a certain height h above the bead core so as to form an adjoining part a bead core cover disposed between the carcass ply and the bead core for preventing cords of the carcass from directly contacting with the bead core, the bead core cover being made of a rubber layer, a space in each bead portion surrounded by the carcass ply main portion, the turnup portion and the bead core filled with a bead apex rubber, the bead apex rubber having a JIS-A hardness of 70 to 100 degrees and tapering radially outwardly from the bead core, the radially outer end of the bead apex disposed at said height h being in a range of from Hâˆ’15 mm to H+15 mm, wherein H is the height of a flange of a standard wheel rim on which the tire is intended to be mounted, and wherein said bead core cover is a rubber layer having a JIS-A hardness being in the range of from 50 to 80 degrees and being less than that of the bead apex rubber and having a substantially constant thickness of from 1.0 to 3.0 mm, and the bead core cover extends continuously from the axially inside to outside of the bead apex through the underside of the bead core, and said bead core cover extends continuously from both the axially inside and outside of the bead apex to the adjoining part so as to form a rubber layer between the carcass ply turnup portion and the main portion which rubber layer has a substantially constant thickness of from 2.0 to 6.0 mm, a JIS-A hardness of 50 to 80 degrees, and a length along the carcass ply of from 5 to 15 mm.