A cord reinforces a rubber article. The cord includes a core strand having a two-layer twisted layer structure formed by intertwining a plurality of filaments, a plurality sheath strands intertwined around the core strand, the sheath strands having a twisted layer structure formed by intertwining a plurality of filaments, and a wrap wire applied around the core strand and at least one of the sheath strands. The wrap wire creating a permanent and stable minimum gap between the core strand and the sheath strands.

Provided is an elastomer reinforcement cord with improved rust inhibition. An elastomer reinforcement cord (10) includes metal filaments and a polymer material. The elastomer reinforcement cord (10) has a multi-strand structure which includes: at least one core strand (21) formed by twisting plural metal filaments (1a) and (1b) together; and two or more sheath strands (22) each formed by twisting plural metal filaments (11a) and (11b) together, and in which the sheath strands are twisted together around the core strand. In a region surrounded by a line connecting the centers of the metal filaments constituting the outermost sheath layer of the core strand at a cross-section in a direction orthogonal to an axial direction after vulcanization of the core strand, when a region occupied by other than the metal filaments is defined as a gap region, a filling rate, which is a ratio of the area of the polymer material with respect to the gap region, is 52% to 120%.

The invention relates to a metallic reinforcing cord (10) for tyres for vehicle wheels, comprising from two to ten metallic wires (11) twisted together with a twisting pitch (P) and each having a predetermined diameter. In at least some cross sections of the metallic reinforcing cord (10), at least two of said metallic wires (11) are arranged to a minimum mutual distance greater than, or equal to, 2.5 times the predetermined diameter.

Disclosed is a radial tire having a cap ply manufactured with a polyethylene terephthalate dip cord. The radial tire includes: a pair of parallel bead cores; at least one radial carcass ply wound around the bead cores; one or more inclined belt layers layered on the outer circumference of the carcass ply; and one or more cap ply layers layered in the circumferential direction of a tire on the outer circumference of the inclined belt layers, wherein the cap ply includes a dip cord manufactured using a yarn comprising 90 mol % or more of polyethylene terephthalate, and the dip cord has a shrinkage of 3.0-4.0%, a strength of 2.5-3.0 g/d at an elongation of 5%, a breaking strength of 6.5-7.5 g/d, and a dimensional stability index of 5.8-6.5.

A two-layer multi-strand cord (60) comprises an internal layer (CI) of the cord made up of J>1 internal strands (TI) and an external layer (CE) of the cord made up of L>1 external strands (TE). The cord satisfies the relationship 95≤MC≤175, where MC=(J×MI+L×ME)/(J+L); MI=200×cos.sup.4(α)×[Q×(D1/2).sup.2×cos.sup.4(β)+N×(D2/2).sup.2×cos.sup.4(γ)]/[Q×(D1/2).sup.2+N×(D2/2).sup.2]; and ME=200×cos.sup.4(α′)×[Q′×(D1′/2).sup.2×cos.sup.4(β′)+P′×(D2′/2).sup.2×cos.sup.4(δ′)+N′×(D3′/2).sup.2×cos.sup.4(β′)]/[Q′×(D1′/2).sup.2+P′×(D2/2).sup.2+N′×(D3′/2).sup.2], where D1, D1′, D2, D2′, and D3′ are in mm, α and α′ are the helix angle of each internal and external strand (TI), β and β′ are the helix angle of each internal thread (F1, F1′), δ′ is the helix angle of each intermediate thread (F2′) and γ and γ′ are the helix angle of each external thread (F2, F3′).

A cord (50) comprises a single layer (52) made up of N helically wound metal filamentary elements (54) having an outer diameter D, the metal filamentary elements (54) defining an internal enclosure (58) of the cord of diameter Dv. Each metal filamentary element (54) has a diameter Df and a helix radius of curvature Rf. With this cord (50), D, Dv, Df and Rf being expressed in millimeters: 0.10≤Jr≤0.25, 9≤Rf/Df≤30, and 1.60≤Dv/Df≤3.20, where Jr=N/(π*(D−Df))×(Dh×Sin(π/N)−(Df/Cos(αx π/180))) and α is the helix angle, expressed in degrees, of each metal filamentary element (54).

A two-layer multi-strand cord (60) comprises an internal layer (CI) of the cord made up of J>1 internal strands (TI) and an external layer (CE) of the cord made up of L>1 external strands (TE). The cord satisfies the relationship 100≤MC≤175, where MC=(J×MI+L×ME)/(J+L); MI=200×cos.sup.4(α)×[Q×(D1/2).sup.2×cos.sup.4(β)+N×(D2/2).sup.2×cos.sup.4(γ)]/[Q×(D1/2).sup.2+N×(D2/2).sup.2]; and ME=200×cos.sup.4(α′)×[Q′×(D1′/2).sup.2×cos.sup.4(β′)+N′×(D2′/2).sup.2×cos.sup.4(γ′)]/[Q′×(D1′/2).sup.2+N′×(D2′/2).sup.2], where D1, D1′, D2, D2′ are in mm, α and α′ are the helix angle of each internal and external strand (TI), β and β′ are the helix angle of each internal thread (F1, F1′), and γ and γ′ are the helix angle of each external thread (F2, F2′).

The method makes it possible to manufacture an assembly (A) comprising a layer (C) of metal filamentary elements (14) wound in a helix. The method comprises a step (100) of supplying a temporary assembly (22) comprising a layer (13) of M′>1 metal filamentary elements (14) and a temporary centre (16), and a step (110) of separating the temporary assembly (22) between a first split assembly (25), a second split assembly (27) and the temporary centre (16). The method comprises a step (140) of reassembling the first split assembly (25) with the second split assembly (27) so as to form the layer (C) of the assembly (A).

A steel cord for the reinforcement of elastomer products such as elevator belts, conveyor belts, synchronous or timing belts or hoses or tyres is presented. The steel cord comprises strands and monofilaments made of steel filaments. The strands themselves are also made of steel filaments twisted together. The strands form the outer layer of the steel cord. The monofilaments are twisted into the cord with the same lay length and direction as the strands and are positioned in the valleys between the strands on the radial outer side of the steel cord. The steel cord has the advantage that it has a better fill factor and a rounder aspect. Furthermore the monofilaments may act as an early wear indicator of the elastomer product.

A steel cord with a construction of m+n having a first group of core filaments having a number of m and a second group of sheath filaments having a number of n, the second group and the first group are twisted around each other with the same twist pitch and same twist direction, wherein the core filaments are not twisted with each other, the core filaments are parallel or have a twist pitch being more than 300 mm, and the sheath filaments have a twist pitch being less than or equal to 30mm, the core filaments have an average tensile strength Tc in MPa when being un-ravelled from said steel cord, the sheath filaments have an average tensile strength Ts in MPa when being un-ravelled from said steel cord, Tc and Ts satisfy: 5<(Tc-Ts)<200. The steel cord has high breaking load and high production efficiency without cost increase.