Abstract: A pneumatic tire includes a tread, a carcass and a belt. The belt includes inner and outer layers including steel cords and topping rubbers such that the cords in each layer are parallel-aligned and inclined with respect to equatorial plane and inclination directions of the cords in the layers are opposite to each other with respect to the plane, inclination angle ?s of the cords in the inner layer at edge is larger than inclination angle ?c at the plane, the edge of the inner layer is at position of 0.9 times axial direction width, inclination angle ?s of the cords in the outer layer at edge is larger than inclination angle ?c o at the plane, the edge of the outer layer is at position of 0.9 times axial direction width, and difference between the angles ?s and ?c is larger than difference between the angles ?s and ?c.

Abstract: To accurately measure a tread radius of a rotating tire. A method for measuring a tread radius has a tread radius measuring process which comprises a measurement step, an averaging step, and a calculation step. In the measurement step, the radial distances from three laser displacement meters to the tread surface of the rotating tire are measured to obtain radial distance data y1, y2, y3 whose number is m per the entire circumference of the tire. In the averaging step, an averaged value y1N, y2N, y3N is obtained by averaging the remaining radial distance data from which noise data have been removed by performing a smoothing process on the number m of the radial distance data y1, y2, y3. In the calculation step, a tread radius TR is calculated from the averaged values y1N, y2N, y3N and the distances x1, x2, x3 of the laser displacement meters in the axial direction of the tire.

Abstract: A pneumatic tire includes a tread, a carcass and a belt. The belt includes inner and outer layers including steel cords and topping rubbers such that the cords in each layer are parallel-aligned and inclined with respect to equatorial plane and inclination directions of the cords in the layers are opposite to each other with respect to the plane, inclination angle ?s of the cords in the inner layer at edge is larger than inclination angle ?c at the plane, the edge of the inner layer is at position of 0.9 times axial direction width, inclination angle ?s of the cords in the outer layer at edge is larger than inclination angle ?c o at the plane, the edge of the outer layer is at position of 0.9 times axial direction width, and difference between the angles as and ac is larger than difference between the angles ?s and ?c.

Abstract: To accurately measure a tread radius of a rotating tire. A method for measuring a tread radius has a tread radius measuring process which comprises a measurement step, an averaging step, and a calculation step. In the measurement step, the radial distances from three laser displacement meters to the tread surface of the rotating tire are measured to obtain radial distance data y1, y2, y3 whose number is m per the entire circumference of the tire. In the averaging step, an averaged value y1N, y2N, y3N is obtained by averaging the remaining radial distance data from which noise data have been removed by performing a smoothing process on the number m of the radial distance data y1, y2, y3. In the calculation step, a tread radius TR is calculated from the averaged values y1N, y2N, y3N and the distances x1, x2, x3 of the laser displacement meters in the axial direction of the tire.

Abstract: A heavy duty radial tire comprises a tread portion divided into four or five circumferential ribs and a tread reinforcing belt including a maximum width belt ply. The width Bw of the maximum width belt ply is 0.90 to 0.98 times the tread width Tw. The contour shape of the tire footprint has a ground contacting length CB at a 70% width position and a ground contacting length CC at a 97% width position, wherein the ratio CB/CC is 1.00 to 1.06. In a tread edge near region J, (1) the axially outermost shoulder rib is provided with no circumferential groove having a width of less than 5 mm, and a ratio Rs/Rc of an axial width Rs of the shoulder rib to an axial width Rc of a center rib is 1.25 to 1.

Abstract: A heavy duty tire comprises: a bead filler disposed radially outside a bead core and axially outside a carcass main portion; a bead-reinforcing layer made of steel cords; and a chafer made of a rubber extending along the bead bottom surface. The chafer rubber has a complex elastic modulus in a range of 8 to 12 MPa and a 100% modulus in a range of 4.0 to 5.5 MPa. In the bead-reinforcing layer, the steel cord count is 25 to 40/5 cm, the steel cord diameter is 0.8 to 1.2 mm, and the cord angle is 30 to 60 degrees with respect to the tire radial direction. The bead filler comprises a main filler made of a low modulus rubber and a fastening filler made of a high modulus rubber. The fastening filler has an L-shaped cross sectional shape and comprises an axially-extending base portion and a radially-extending axially inner portion. The main filler has a part wedged between the base portion and axially inner portion of the fastening filler.

Abstract: A heavy duty tire comprises a belt disposed radially outside a carcass. The belt consists of a innermost first ply, a second ply and a outermost third belt ply. With respect to the tire equator, the cords of the first ply are laid at an angle ?1 of 15 to 25 degrees; the cords of the second ply are laid at an angle ?2 of 15 to 25 degrees; the cords of the third ply are laid at an angle ?3 of 45 to 60 degrees; the cords of the second ply are inclined oppositely to the cords of the first ply; the cords of the third ply are inclined to the same direction as the cords of the second ply; |?2??1| is not more than 5 degrees; |?3??2| is 30 to 45 degrees; the axial widths W1, W2 and W3 of the first, second and third belt plies, respectively, satisfy W1>W2>W3; strengths S1, S2 and S3 of the first, second and third belt plies, respectively, satisfy S1>S2>S3 and 1.0>S2/S1>=0.6.

Abstract: A method includes a tubular carcass with core forming process (K1), a rubber laminate forming process (K2), and a tubular base tire forming process (K4). The forming process (K1) of forming a tubular carcass with bead core (6R3) on a first drum (20) comprises a tubular carcass forming step (K1a) to form a tubular carcass (6R2) by butt-jointing circumferential end faces of a carcass ply member (6R1) wound singly on the first drum (20), and a bead core joining step (K1b) to form integrally by diameter-expanding and pressing the tubular carcass (6R2) against the bead cores (5) outserted on the radially outer side. In the forming process (K2), rubber members for base tire (Ga) including an inner liner rubber member (G10a) are wound on a second drum (27) so as to form a rubber laminate (11).

Abstract: A heavy-load radial tire includes a bead apex rubber 8 composed of a high-elastic lower apex portion 11 and a low-elastic upper apex portion 12. The lower apex portion 11 has an L-shaped cross section composed of a bottom piece portion 11a disposed along the radially outer surface of a bead core 5 and a standing piece portion 11b standing from the axially inner end of the bottom piece portion 11a and radially outwardly extending along a ply main portion 6a of a carcass 6. At an outer end position P1 of a ply turnup portion 6b, the upper apex portion 12 has a thickness T1s of 0.50 to 0.75 times a core width Bw of the bead core 5. At an outer end position P2 of an outer wound-up portion 9o of a bead reinforcing cord layer 9, the upper apex portion 12 has a thickness T2s of 0.57 to 0.90 times the core width Bw. The core width Bw is 0.68 to 0.80 times a bead bottom width BL.

Abstract: A heavy-load tire has a wind bead structure in which a turned-up portion of a carcass ply is wound around a bead core, in which a bead portion is equipped with a bead reinforcing layer having a u-shaped cross section and a bead apex rubber having a triangular-shaped cross section. The turned-up portion has an auxiliary turned-up portion passing through the vicinity of a radially outer side of the bead core. The bead apex rubber includes a high complex elasticity modulus inner apex portion disposed at a radially inner side and a low complex elasticity modulus outer apex portion disposed at a radially outer side.

Abstract: A heavy-duty pneumatic tire includes a carcass ply turned up around a bead core in each bead portion from the inside to the outside of the tire so as to have a pair of turnup portions and a main portion therebetween; and a bead apex and an L-shaped reinforcing cord layer. The bead apex includes: an L-shaped high-modulus inner bead apex including a base part and a radial part; and a delta-shaped low-modulus outer bead apex disposed on the radially outside of the base part of the L-shaped inner bead apex and on the axially outside of the radial part of the L-shaped inner bead apex. The L-shaped reinforcing cord layer is made up of an radially inner part extending on the radially inner side of the bead core, and an radially outer part extending along the axially outer surface of the carcass ply turnup portion.

Abstract: A heavy duty tire comprises a belt disposed radially outside a carcass. The belt consists of a innermost first ply, a second ply and a outermost third belt ply. With respect to the tire equator, the cords of the first ply are laid at an angle ?1 of 15 to 25 degrees; the cords of the second ply are laid at an angle ?2 of 15 to 25 degrees; the cords of the third ply are laid at an angle ?3 of 45 to 60 degrees; the cords of the second ply are inclined oppositely to the cords of the first ply; the cords of the third ply are inclined to the same direction as the cords of the second ply; |?2??1| is not more than 5 degrees; |?3??2| is 30 to 45 degrees; the axial widths W1, W2 and W3 of the first, second and third belt plies, respectively, satisfy W1>W2>W3; strengths S1, S2 and S3 of the first, second and third belt plies, respectively, satisfy S1>S2>S3 and 1.0>S2/S1>=0.6.

Abstract: A heavy-load tire has a wind bead structure in which a turned-up portion of a carcass ply is wound around a bead core, in which a bead portion is equipped with a bead reinforcing layer having a U-shaped cross section and a bead apex rubber having a triangular-shaped cross section. The turned-up portion has an auxiliary turned-up portion passing through the vicinity of a radially outer side of the bead core. The bead apex rubber includes a high complex elasticity modulus inner apex portion disposed at a radially inner side and a low complex elasticity modulus outer apex portion disposed at a radially outer side.

Abstract: A heavy-load tire has a wind bead structure in which a turned-up portion of a carcass ply is wound around a bead core, in which a bead portion is equipped with a bead reinforcing layer having a u-shaped cross section and a bead apex rubber having a triangular-shaped cross section. The turned-up portion has an auxiliary turned-up portion passing through the vicinity of a radially outer side of the bead core. The bead apex rubber includes a high elasticity inner apex portion disposed at a radially inner side and a low elasticity outer apex portion disposed at a radially outer side. The inner apex portion has an L-shaped cross section including a bottom piece portion along the radially outer side of the auxiliary turned-up portion, and a raised piece portion which rises at an axially inner end side of the bottom piece portion and extends radially outwardly in a tapering manner along the body portion of the carcass ply.

Abstract: A heavy duty tire comprises: a carcass ply of cords extending between bead portions; and a bead reinforcing layer disposed in each of the bead portion. The carcass ply has edges winded around the bead cores so that the winded portion has a base part extending along the bead core from the axially inside to the axially outside thereof, and a radially outer part extending axially inwards on the radially outside of the bead core. The bead reinforcing layer comprises: a curved portion extending along the base part; an axially outer portion extending radially outwardly, separation from the base part; and an axially inner portion extending radially outwardly along a main portion of the carcass ply. The bead reinforcing layer is composed of a ply of cords laid side by side, and the spacing Da of the cords in an axially outer part beneath the bead core, of the curved portion is not less than 1.5 times and not more than 3.0 times the spacing Db of the cords in the axially outer portion.

Abstract: A heavy duty tire comprises a bead filler disposed in each bead portion (4). The bead filler (8) comprises: a main layer (13) having a complex elastic modulus E*2 of from 2.0 to 6.0 Mpa; and a fastening layer (12) having a complex elastic modulus E*1 of from 20 to 70 Mpa. The fastening layer comprises a base portion (12B) and an axially inner portion (12A) to have a L-shaped cross section. The height Ha of the axially inner portion (12A) is 35 to 100 mm and not more than the height Hb of the main layer (13), and the radial height Hb is 40 to 100 mm, each from the bead base line.

Abstract: A heavy duty radial tire comprises a tread portion divided into four or five circumferential ribs and a tread reinforcing belt including a maximum width belt ply. The width Bw of the maximum width belt ply is 0.90 to 0.98 times the tread width Tw. The contour shape of the tire footprint has a ground contacting length CB at a 70% width position and a ground contacting length CC at a 97% width position, wherein the ratio CB/CC is 1.00 to 1.06. In a tread edge near region J, (1) the axially outermost shoulder rib is provided with no circumferential groove having a width of less than 5 mm, and a ratio Rs/Rc of an axial width Rs of the shoulder rib to an axial width Rc of a center rib is 1.25 to 1.

Abstract: A heavy-load radial tire includes a bead apex rubber 8 composed of a high-elastic lower apex portion 11 and a low-elastic upper apex portion 12. The lower apex portion 11 has an L-shaped cross section composed of a bottom piece portion 11a disposed along the radially outer surface of a bead core 5 and a standing piece portion 11b standing from the axially inner end of the bottom piece portion 11a and radially outwardly extending along a ply main portion 6a of a carcass 6. At an outer end position P1 of a ply turnup portion 6b, the upper apex portion 12 has a thickness T1s of 0.50 to 0.75 times a core width Bw of the bead core 5. At an outer end position P2 of an outer wound-up portion 9o of a bead reinforcing cord layer 9, the upper apex portion 12 has a thickness T2s of 0.57 to 0.90 times the core width Bw. The core width Bw is 0.68 to 0.80 times a bead bottom width BL.

Abstract: A pneumatic tire 1 having improved uniformity and durability and including a toroidal carcass 6 extending from a tread portion 2 to each of bead cores 5 in bead portions 4 through sidewall portions 3, a belt layer 7 disposed radially outward of the carcass 6 in the tread portion 2, and a cushion rubber 9 having an approximately triangular cross section disposed between the carcass 6 and each of axial edge portions 7E of the belt layer 7, and a method for producing the same, wherein the cushion rubber 9 is made from a strip laminated body formed by circumferentially and spirally winding a first ribbon-like unvulcanized rubber strip and a second ribbon-like unvulcanized rubber strip having a different composition from that of the first rubber strip.

Abstract: A heavy duty tire comprises a belt disposed radially outside a carcass in the tread portion, and a belt cushion rubber layer inserted between the carcass and each axial edge portion of the belt. The complex elastic modulus of the belt cushion rubber layer is in a range of from 3.5 to 4.5 MPa. The belt is made up of three plies each made of parallel steel cords inclined at an angle of from 15 to 23 degrees with respect to the tire equator. With respect to the tire equator, the inclination of the belt cords of the radially innermost first ply is opposite to that of the middle second belt ply. The second belt ply is narrower than the first belt ply and wider than the radially outermost third belt ply. The ply strengths S1, S2 and S3 of the first, second and third belt plies, respectively, satisfy: (1) S1>S2, (2) S1>S3, (3) 55?S1?75, and (4) 1.25?S1/S2?1.65.