Abstract: A heavy duty tire comprises a single carcass ply and a tread reinforcing belt. Each carcass ply turnup portion comprises a base part under a bead core and a radially outer part extending axially inwardly towards the carcass ply main portion. The belt consists of three plies of cords, wherein the cords of the radially outer ply are inclined toward one direction at an angle of from 13 to 23 degrees with respect the fire equator; the cords of the intermediate ply are inclined at an angle of from 13 to 23 degrees toward one direction being opposite to that of the radially outer ply; and the cords of the radially inner ply are arranged at an angle of from 30 to 70 degrees toward one direction being opposite to that of the radially outer belt ply.

Abstract: A pneumatic tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions with a bead core therein, and a carcass ply extending between the bead portions through the tread portion and sidewall portions and wound around the bead core in each of the bead portions from the axially inside to the axially outside of the tire so as to form a pair of wound portions and a main portion therebetween. The bead core has a cross sectional shape elongated in a direction substantially parallel to the bottom of the bead portion so that the width thereof measured in this direction is in a range of from 1.5-2.5 times the height thereof measured perpendicularly thereto. The bead core is covered with a high modulus rubber layer having a complex elastic modulus E*1 of from 20-100 Mpa and a thickness of t1 of from 0.5-3.0 mm.

Abstract: A heavy duty tire comprises a bead core disposed in each bead portion, and a carcass ply of steel cords extending between the bead portions. The edges of the carcass ply are winded around the bead cores from the axially inside to outside of the tire to form a pair of winded portions and a main portion therebetween. The winded portion around the bead core comprises an axially inwardly extending turnback part above the bead core, and a base part under the bead core. The base part is curved concavely so as to form a space between the base part and the bead core, and an anchor rubber having a complex elastic modulus of from 20 to 80 MPa is disposed in the space to tightly pinch the carcass cords between the anchor rubber and the bead seat of the wheel rim.

Abstract: A heavy duty tire including bead portions each with a bead core, and a carcass ply containing a main portion extending between bead portions and a pair of edge portions wound around the bead cores, the wound edge portion including a turnback part extending axially inwardly from a position on the axially outside of the bead core and an auxiliary cord layer disposed on the radially outside of the turnback part, whereby the end of the turnback part is positioned at a distance of from 2.0 to 8.0 mm from the radially outer surface of the bead core. In a normally inflated unloaded state of the tire, the turnback part is curved such that the diameter of the turnback part decreases continuously from the end to the position in the axial outside of the bead core.

Abstract: A pneumatic tire comprises a tread portion with tread edges, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a carcass ply of cords comprising a main portion extending between the bead cores through the tread portion and sidewall portions and a wound portion wound around the bead core in each said bead portion from the inside to the outside of the tire, and an edge of the wound portion is disposed between the bead core and a bead apex rubber disposed radially outside the bead core to be secured therebetween.

Abstract: A heavy duty tire comprises a bead core disposed in each bead portion, and a carcass ply of steel cords extending between the bead portions. The edges of the carcass ply are winded around the bead cores from the axially inside to outside of the tire to form a pair of winded portions and a main portion therebetween. The winded portion around the bead core comprises an axially inwardly extending turnback part above the bead core, and a base part under the bead core. The base part is curved concavely so as to form a space between the base part and the bead core, and an anchor rubber having a complex elastic modulus of from 20 to 80 MPa is disposed in the space to tightly pinch the carcass cords between the anchor rubber and the bead seat of the wheel rim.

Abstract: A heavy duty tire comprises a carcass ply turned up around a bead core in each bead portion to form a pair of turnup portions and a main portion, and a bead reinforcing layer disposed in the bead portion and comprising an axially outer part and an axially inner part, wherein under a 50 kPa state of the tire in which the tire is mounted on a standard rim and inflated to 50 kpa: the turnup portion inclines towards the carcass ply main portion at an angle of less than 90 degrees; the distance La of the end of the turnup portion 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 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.

Abstract: A heavy duty tire comprises a single carcass ply and a tread reinforcing belt. Each carcass ply turnup portion comprises a base part under a bead core and a radially outer part extending axially inwardly towards the carcass ply main portion. The belt consists of three plies of cords, wherein the cords of the radially outer ply are inclined toward one direction at an angle of from 13 to 23 degrees with respect the tire equator; the cords of the intermediate ply are inclined at an angle of from 13 to 23 degrees toward one direction being opposite to that of the radially outer ply; and the cords of the radially inner ply are arranged at an angle of from 30 to 70 degrees toward one direction being opposite to that of the radially outer belt ply. The total of strengths of the three belt plies is in a range of from 120 to 170 kN. Preferably, the strengths satisfy (1) Intermediate ply>=Outer ply>=Inner ply and (2) Intermediate ply>Inner ply.

Abstract: A heavy duty tire comprises a carcass ply turned up around a bead core in each bead portion to form a pair of turnup portions and a main portion, and a bead reinforcing layer disposed in the bead portion and comprising an axially outer part and an axially inner part, wherein under a 50 kPa state of the tire in which the tire is mounted on a standard rim and inflated to 50 kpa: the turnup portion inclines towards the carcass ply main portion at an angle of less than 90 degrees; the distance La of the end of the turnup portion 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 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.

Abstract: A pneumatic tire comprises a tread portion with tread edges, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a carcass ply of cords comprising a main portion extending between the bead cores through the tread portion and sidewall portions and a wound portion wound around the bead core in each said bead portion from the inside to the outside of the tire, and an edge of the wound portion is disposed between the bead core and a bead apex rubber disposed radially outside the bead core to be secured therebetween.