Improving endurance of bead of radial tire for heavy vehicle. Tire has two beads (2) contacting rim (3) connected by carcass reinforcement (4) having carcass layer (5), with main part (6) wrapped, in each bead (2), axially from inside towards outside of the tire, around bead wire (7) having diameter (L), to form turnup (8) having free end (E). Each bead (2) has filling element (9) with filling compound (10) and extending radially towards outside from bead wire (7) and axially between turnup (8) and main part (6). The distance (I) between turnup (8) and main part (6) decreases continuously from bead wire (7) as far as a first minimum distance (a) reached at a first point (A) of turnup (8), then increases continuously from the first point (A) of turnup (8) as far as a first maximum distance (b) reached at a second point (B) of turnup (8).

Resistance to unseating of a passenger is achieved by a tire comprising a bead having an axial width at the seat D comprising a circumferential reinforcing element (22) of which the radially innermost point (222) is at a radial distance Z and at an axial distance Y from the radially innermost point (211) of the bead, and such that Y/D is at least equal to 0.5 and Z/D is at most equal to 0.4. The end of the carcass reinforcement (311) is situated radially on the outside of the radially outermost point (223) of the circumferential reinforcing element. This same bead comprises at least one bead layer (23) surrounding the bead filler rubber (21) and such that its axially outermost end (231) is radially on the outside of the end (311) and such that its axially innermost end (232) is at least radially on the outside of the point (222).

A tire design for a heavy-duty vehicle of construction plant type has a crown reinforcement (40) radially on the inside of a tread (10) and radially on the outside of a carcass reinforcement (70). The carcass reinforcement (70) has at least two carcass layers (50, 60) having metal reinforcers coated in an elastomer compound. The carcass layers (50, 60) have respective stiffnesses per unit width R1, R2. Metal reinforcers of a first carcass layer (50) form, with the circumferential direction (XX′), an angle A1, and those of the second carcass layer form an angle A2, such that the angles A1 and A2, and the stiffnesses R1 and R2, simultaneously satisfy the following three relationships: R1*sin 2(2*A1)+R2*sin 2(2*A2)≥(R1+R2)*) sin 2(30°), and ∥A1|-|A2∥<10°, and 0.7≤R1/R2≤1.3. The metal reinforcers have a critical compression buckling deformation DF at least equal to 2.5% and a compression elastic modulus MC at least equal to 10 GPa.

There is provided an pneumatic tire including a pair of left and right beads each including a bead core and a bead filler, and a carcass ply extending between the pair of beads, wherein the carcass ply is wound up around the bead core from the outside to the inside in the widthwise direction of the tire, and an end portion of the wind-up portion of the carcass ply is provided with notches at a plurality of positions in the circumference direction of the tire.

A pneumatic tire includes: paired bead portions respectively including annular bead cores and bead fillers disposed on an outer side in a tire radial direction of the bead cores; sidewall portions respectively extending outward in the tire radial direction from the bead portions; a tread portion connected to cuter ends in the tire radial direction of the sidewall portions to form a tread; and a carcass layer suspended between the bead portions. The carcass layer has a first ply that continuously extends between the bead portions and that has opposite end portions respectively and a second ply that continuously extends on the outer side in the tire radial direction of the first ply, wherein the first ply has higher tensile strength than that of the second ply, and the end portion is positioned on the outer side in the tire radial direction of the end.

In a pneumatic tire, a bead filler is on an outer circumference of a bead core, a carcass turned up end is inward of an outer diameter side end of the bead filler, the carcass end is spaced from a carcass body, a steel reinforcement is in each bead, a sidewall rubber extends from the sidewall to the bead, and a support layer is between the bead filler and the sidewall rubber to cover the carcass end and an end of the steel reinforcement, the support layer extending toward an outer diameter side and contacting the carcass body on an outer diameter side of the bead filler outer diameter side end, and a 100% modulus of the support layer is at least 1.5 times that of the bead filler, and the sidewall rubber, the bead filler and the sidewall rubber being adjacent to the support layer.

A pneumatic tire 1 has a carcass 6 extending between a first bead portion 4A and a second bead portion 4B through a tread portion 2 and a pair of sidewall portions 3. The carcass 6 is composed of at least two carcass plies 7 including a first carcass ply 7A and a second carcass ply 7B which have the same ply length. Each of the first carcass ply 7A and the second carcass ply 7B is arranged asymmetrically with respect to the tire equator C.

In a pneumatic tire, a bead filler is radially outward of a bead core, a carcass turned up end is radially inward of an outer side end of the bead filler, the turned up end is spaced from a carcass body, a reinforcement layer is laterally outward of the bead filler, a sidewall rubber extends from a sidewall to the bead, an inner rubber reinforcing layer is between the bead filler and the reinforcement layer and adjacent to the turned up end, a crack suppression layer is between the reinforcement layer and the sidewall rubber, the crack suppression layer extends 5 mm or more from where the crack suppression layer overlaps, the reinforcement layer contacts the carcass body radially outwardly of the bead filler, and a 100% modulus Kc.sub.M100 of the crack suppression layer is at least 1.5 times that of the sidewall rubber.

A pneumatic tire includes: paired bead portions respectively including annular bead cores and bead fillers disposed on an outer side in a tire radial direction of the bead cores; sidewall portions respectively extending outward in the tire radial direction from the bead portions; a tread portion connected to outer ends in the tire radial direction of the sidewall portions to form a tread; a carcass layer suspended between the bead portions; and a belt layer provided on an outer side in the tire radial direction of the carcass layer in the tread portion. The carcass layer has a first ply that continuously extends between the bead portions and that has opposite end portions and a second ply that extends from a position in contact with an inner peripheral face of an end portion, wherein the second ply has higher tensile strength than the tensile strength of the first ply.

A pneumatic tire has a turned-up carcass ply and a non-turnup carcass ply. The turned-up carcass ply is turned up around bead cores in respective bead portions from the inside to outside of the tire so as to form a pair of turned up portions extending radially outwardly on the axially outsides of the respective bead cores, and a main portion extending between the turned up portions. The non-turnup carcass ply extends between the bead portions and terminates to have edges positioned on the axially outsides of the respective turned up portions. The bead portions are each provided on its outer surface with vent lines protruding therefrom and extending continuously in the tire circumferential direction. The vent lines include a radially outer vent line formed radially outside the edges of the non-turnup carcass ply, and a radially inner vent line formed radially inside the edges of the non-turnup carcass ply.