A tire (1) for a heavy construction plant vehicle with satisfactory compromise between the breaking strength of its circumferential hoop reinforcement (7), having an axial width LF and having a circumferential hooping layer (71, 72) with elastic metallic reinforcers having a structural elongation AS and a force at break FR, and forming an angle at most equal to 5° with the circumferential direction (XX), and the endurance of its working reinforcement (6), formed by two working layers (61, 62) with inextensible metallic reinforcers, the mean angle AM of which with the circumferential direction (XX′) is at least equal to 15° and at most equal to 45°. The axial width LF, the structural elongation As, the force at break Fr and the mean angle AM satisfy the relationship:

Zn/Z0*(T0+(a1+a2*As)/AM+b*LF*(AM−A0)/A0+c*AM)<Fr/CS, where Zn is the nominal load, Z0=100 t, T0=7000 N, a1=−230,000 N*°, a2=−160,000 N*°/%, b=−34,000 N/m, A0=29°, c=550 N/°, CS>=1.

In a pneumatic tire including a carcass layer mounted between a pair of bead portions and a belt reinforcing layer disposed on an outer circumferential side of the carcass layer, the carcass layer is formed of a carcass cord made of an organic fiber cord, an elongation at break of the carcass cord is set to 20% or more, an elongation under a load of 1.5 cN/dtex of the carcass cord in sidewall portions is set to from 5.0% to 8.0%, the belt reinforcing layer is formed of a cover cord made of an organic fiber cord, and a tensile strength of the cover cord per width of 50 mm at a 3.0% elongation is set to from 2.8 kN to 4.0 kN.

In a pneumatic tire including a carcass layer mounted between a pair of bead portions and a belt reinforcing layer disposed on an outer circumferential side of the carcass layer, the carcass layer is formed of a carcass cord made of an organic fiber cord, an elongation at break of the carcass cord is set to 20% or more, an elongation under a load of 1.5 cN/dtex of the carcass cord on the inner circumferential side of the belt layers is set to from 5.5% to 8.5%, the belt reinforcing layer is formed of a cover cord made of an organic fiber cord, and a tensile strength of the cover cord per width of 50 mm at a 3.0% elongation is set to from 2.8 kN to 4.0 kN.

Provided is a pneumatic tire. A belt cover layer including organic fiber cords spirally wound along the tire circumferential direction is provided on the outer circumferential side of a belt layer in a tread portion. The belt cover layer includes at least one full cover layer covering the entire width direction of the belt layer, and the number of layers in the shoulder region is two or less. Polyethylene terephthalate fiber cords of which the elastic modulus at a load of 2.0 cN/dtex at 100° C. is in a range of 3.5 cN/(tex•%) to 5.5 cN/(tex•%) are used as the organic fiber cords constituting the belt cover layer. The ratio Sh/Ce of a rising amount Sh in the shoulder region and a rising amount Ce at a tire equator position during traveling at 240 km/h is 0.85 to 1.15.

A pneumatic radial tire includes belt layers disposed on an outer circumferential side of a carcass layer in a tread portion. The belt layers are formed of steel cords in a N+M structure in which the number of wire strands N of an inner layer is 2 to 4 and the number of wire strands M of an outer layer is 2 to 7. A twist direction of the inner layer is different from a twist direction of the outer layer. The steel cords are inclined with respect to a tire circumferential direction to intersect each other in layers of the belt layers. A belt cover layer disposed on an outer circumferential side of the belt layers is formed of organic fiber cords having elongation of 2.0% to 4.0% under 2.0 cN/dtex load. The organic fiber cords are wound spirally along the tire circumferential direction.

Pneumatic vehicle tyres which have a bandage ply (8) comprising two lateral portions (10) and a center portion (12) in the axial extension, wherein each lateral portion (10) has at least one hybrid reinforcement, and wherein the center portion (12) has at least one reinforcement which has a lower modulus of elasticity than the hybrid reinforcements of the lateral portions (10), in each case measured as per ASTM D885M at an elongation of 3%. It is the object of the invention to provide a tyre with reduced rolling resistance and good high-speed characteristics with reliable producibility. This is achieved in that the hybrid reinforcement is a hybrid cord made of at least one low-modulus thread and one high-modulus thread twisted together, and in that the hybrid reinforcement has a fineness of at most 550 dtex, preferably at most 500 dtex, particularly preferably at most 460 dtex, and in that the reinforcement of the center portion (12) has a fineness of at most 1100 dtex, preferably at most 600 dtex, particularly preferably at most 500 dtex.

A radial tire (1) for a heavy-duty vehicle of construction plant type, and aims to increase the rupture strength of the hoop reinforcement thereof having circumferential layers, ensuring satisfactory endurance of the crown reinforcement thereof. According to the invention, the at least one circumferential hooping layer (71, 72) comprises a median portion (711, 721) having a median width (L11, L21) and a median tensile elastic modulus (E11, E21), and two lateral portions (712, 722) that axially extend the median portion (711, 721) on either side and each have a lateral width (L12, L22) and a lateral tensile elastic modulus (E12, E22), the lateral width (L12, L22) is at least equal to 0.05 times the median width (L11, L21), and the lateral tensile elastic modulus (E12, E22) is at most equal to 0.9 times the median tensile elastic modulus (E11, E21).

A pneumatic tire comprising a carcass 12, at least one inclined belt layer 13, at least one first circumferential cord layer 14 arranged inward in the tire radial direction of the inclined belt layer 13, a tread 16 arranged outward in the tire radial direction of the inclined belt layer 13, and a second circumferential cord layer 15 which is arranged outward in the tire radial direction so as to cover a tire width direction end of the inclined belt layer 13, and where X is defined as X=Y×n×m×d, Y is the Young's modulus (GPa) of the cord, n is the number of cords implanted (cords/50 mm), d is the cord diameter (mm), and m is the number of the first circumferential cord layers 14, X is smaller than X of the first circumferential cord layer 14.

A passenger vehicle tire having hooping layer (71) that has a force at break FR per mm of axial width of the hooping layer at least equal to 35 daN/mm and has a secant extension modulus MA at least equal to 250 daN/mm, for an applied force F equal to 15% of FR. Working reinforcement (6) comprises a single working layer (61) the working reinforcers of which form, with the circumferential direction (YY′), an angle A.sub.T at least equal to 30° and at most equal to 50°. The carcass reinforcers of the at least one carcass layer (81) form, with the circumferential direction (YY′) and in the equatorial plane (XZ), an angle A.sub.C2 at least equal to 55° and at most equal to 80° and having an orientation opposite of that of angle A.sub.T of the working reinforcers so that the carcass reinforcers and the working reinforcers constitute a triangulation.

The present invention relates to a tyre (1) comprising:—a carcass (5);—at least one high elongation belt (1, 2, 3, 4), being applied as a single cord externally to said carcass (5); and—an external tread portion (6), provided with two or more grooves (7) extending according to a circumferential direction (L) around said tread portion (6), wherein the axial width (Wg) of at least one of said grooves (7), measured according to an axial direction (A) parallel to an axis of rotation (R) of said tyre (10) and orthogonal to said circumferential direction (L), is at most equal to 2 millimeters.