Patent ID: 7040368

Claim:
A heavy duty tire comprising a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, a carcass ply extending between the bead portions through the tread portion and sidewall portions, and turned up around the bead core in each said bead portion from the axially inside to the axially outside of the tire to form a pair of turnup portions and a main portion between the bead cores, and a bead reinforcing layer disposed in each said bead portion, wherein the turnup portion comprises a base part which curves along an axially inner side, a radially inner side and an axially outer side of the bead core, and a deviating part extending axially inwards away from the bead core, said bead reinforcing layer comprises a curved part extending along the radially inside of the base part of the turnup portion, an axially outer part extending radially outwardly away from the base part, while slightly inclining axially outwards, and an axially inner part extending along the axially inside of the carcass ply main portion, under a 50 kPa state of the tire in which the tire is mounted on a standard rim and inflated to 50 kPa; said deviating part inclines towards the carcass ply main portion at an angle theta of less than 90 degrees with respect to the radially outer side of the bead core; the distance La of the end of said deviating part from the radially outer side of the bead core is in a range of from 5 to 12 mm; the radial height Ho of the axially outer part from the bead base line is in a range of from 20 to 35 mm; the distance To of the end of the axially outer part from the axially outer surface of the bead portion is in a range of from 6 to 12 mm; and the ratio To/Ho of the distance To to the height Ho is in a range of from 0.25 to 0.5.