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.

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.

Assembly comprising a tire and a mounting rim, the tire comprising two beads each comprising at least one annular reinforcing structure and a carcass reinforcement anchored in the two beads by a turn-up, each bead comprising a filler of a rubber composition extending radially a radial distance DBE from the radially innermost point of the annular reinforcing structure, DBE being less than or equal to 10% of the radial height H of the tire, at least one sidewall further comprising a stiffening reinforcement of metallic reinforcing elements oriented at an angle less than or equal to 10 degrees to the circumferential direction, and positioned such that the distance DAE between the radially innermost point of the annular reinforcing structure and the radially outer end of the stiffening reinforcement is greater than or equal to 20% and less than or equal to 40% of H and that the distance DAI between the radially inner point of the annular reinforcing structure and the radially inner end of the stiffening reinforcement is less than or equal to 20% of H.

A tire includes a carcass structure including at least one carcass ply, a belt structure applied in a radially outer position with respect to the carcass structure and a tread band applied in a radially outer position with respect to the belt structure. The belt structure includes at least one reinforcing strip incorporating a plurality of reinforcing elements arranged substantially in the circumferential direction. The reinforcing elements include at least one high-elongation metal cord. The metal cord includes a plurality of intertwined strands and each strand includes a plurality of filaments. Advantageously all the filaments of each strand have a diameter not greater than 0.175 mm.

A rubber-metal adhesion promoter characterized by including: a metal salt (1) of a carboxylic acid which is a metal salt of an aliphatic carboxylic acid having 2 to 25 carbon atoms and in which the metal is bismuth, copper, antimony, silver or niobium; or a compound (2) represented by the following general formula (A): [wherein Z represents a structure selected from the following formulae (z-1) to (z-4); M represents bismuth, copper, antimony, silver or niobium; (RCOO) represents a residue of an aliphatic carboxylic acid having 2 to 25 carbon atoms; and x represents the valence of M minus 1]. ##STR00001##

This steel cord for reinforcing a rubber article includes one core strand having a two-layer twisted layer structure formed by intertwining a plurality of steel filaments, and a plurality of sheath strands having a twisted layer structure formed by intertwining a plurality of steel filaments. The sheath strands are intertwined around the core strand, a core of the core strand is formed by two core filaments, and the diameter of outermost layer sheath filaments forming an outermost layer sheath of each sheath strand is greater than the diameter of filaments inside the outermost layer sheath of the sheath strand.

A steel cord includes one or more core filaments, and outer sheath filaments provided so as to surround the one or more core filaments. The one or more core filaments and the outer sheath filaments have an identical wire diameter and an identical twist pitch. At least one of the one or more core filaments is a waved filament having a bent portion and a non-bent portion along a longitudinal direction.

A heavy-duty pneumatic tire includes a section width being equal to or less than 335 mm, an aspect ratio being equal to or less than 55%, and a toroidal carcass extending between axially spaced bead portions through a tread portion and sidewall portions. The carcass includes a carcass ply which includes a main portion and a turn-up portion turned up around a bead core of each bead portion. A belt layer is disposed radially outward of the carcass in the tread portion, wherein a radially outer end of the turn-up portion is located between the main portion and the belt layer in the tread portion. A sheeted rubber layer is disposed between the main portion and the turn-up portions in each sidewall portion.

At least a metallic part of a metal or metallized reinforcer, at least the surface of which is at least partially metallic, is coated with a polybenzoxazine, the repeat units of which comprise at least one unit corresponding to the formulae (I) or (II): ##STR00001##
in which Z.sub.1 represents an at least divalent, aliphatic, cycloaliphatic or aromatic bonding group comprising at least one carbon atom and optionally at least one heteroatom selected from O, S, N and P; X.sub.1 and X.sub.2, which are identical or different, represent O or S; Ar.sub.1 and Ar.sub.2, which are identical or different, represent a substituted or unsubstituted phenylene group; and Z.sub.2 represents O or (S).sub.n, the symbol “n” representing an integer equal to 1 or greater than 1. Such a reinforcement can be used for the reinforcement of a rubber article, in particular a motor vehicle tyre.

The method allows the manufacture of at least first and second assemblies (26, 28) of M1 filamentary elements and M2 filamentary elements, at least one of the first and second assemblies (26, 28) comprising several filamentary elements (14) wound together in a helix.

The method comprises a step of assembling M filamentary elements (14) together into a layer of the M filamentary elements (14) around a temporary core (16) to form a temporary assembly (22), and a step of splitting the temporary assembly (22) into at least the first and second assemblies (26, 28) of M1 filamentary elements and M2 filamentary elements.