A method for manufacturing a straight steel monofilament for the reinforcement of belt ply of a pneumatic tyre, where the arc-height of the straight steel monofilament is less than 30 mm. The steel monofilament is plastically deformed by a twisting along the axis of the steel monofilament on a double-twist apparatus. The plastic twist deformation eliminates the surface stress difference on the steel monofilament and provides a strainght steel monofilament for belt ply reinforcement. This provides a simple solution with existing apparatus to manufacture straight steel monofilament suitable for tire reinforcement with high speed for mass production.

A tire includes a carcass ply, a tread disposed radially outward of a crown region of the carcass ply, and a belt structure having an overall axial width substantially equal to a tread width interposed between the tread and the crown region in circumferential surrounding relation to the carcass ply. The belt structure includes a first belt layer and a second belt layer radially adjacent the first belt layer. The first belt layer includes a first reinforced composite with first reinforcement cords embedded in a first rubber matrix. The first reinforcement cords have a construction of 1100/4 dtex with a twist between 150 TPM and 250 TPM and a dipping tension between 100 mN/tex and 200 mN/tex.

Heavy goods vehicle tire, having a crown portion covered radially on the outside by a tread, this tread having at least two cut-outs, the central portion of the tread having a width Lc of between 35% and 70%, the crown portion comprising a reinforcement having at least two working layers having reinforcing elements, these reinforcing elements consisting of UHT-grade threads, having a mechanical breaking strength R satisfying the following relation: R≥(4180−2130×D), where D is the diameter of the thread expressed in millimetres, this tread being formed of at least two layers of superimposed material, the material forming the first layer with a breaking elongation of more than 600% at a temperature of 60° C., this tread being such that, in the central portion, the cavity ratio per unit volume is not more than 10% and the surface cavity ratio as new is not more than 10%.

The invention relates to a rubberized reinforcing ply (1) for articles consisting of an elastomeric material, preferably for vehicle tires, wherein the reinforcing ply (1) has a multiplicity of textile strengthening members (2) which are arranged parallel to and spaced apart from one another, wherein each textile strengthening member (2) is composed of at least one twisted multifilament yarn, and wherein the textile strengthening member (2) is not composed of the material rayon. The reinforcing ply (1) satisfies the following condition: (D.sup.2/E.sub.0) in mm corresponds to a value in a range from 0.22 mm to 0.38 mm, and the reinforcing ply (1) has a strength of >10 kN/dm, where D is the diameter of the textile strengthening member (2) in mm and lies in a range from 0.38 mm to 0.52 mm, and where E.sub.0=100/epdm.

The invention provides a steel cord for rubber reinforcement. The steel cord comprises a core strand and at least three outer strands twisted around the core strand, the core strand comprises at least one first core filament and multiple first outer filaments twisted around the first core filament, each outer strand comprises a number of second filaments, at least one of multiple first outer filaments is preformed prior to being twisted into the core strand, and at least one of second steel filaments is straight prior to being twisted to form each outer strand. The steel cord has improved performance on core filament migration.

Provided is a pneumatic tire with an annular-shaped tread portion extending in a tire circumferential direction, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed inward of these sidewall portions in a tire radial direction. This pneumatic tire is also provided with a reinforcing member which includes a plurality of reinforcing cords oriented in at least three directions, and has a mesh-like structure with at least three of the reinforcing cords oriented in different directions joined together at at least a portion of intersecting locations of the reinforcing cords.

A steel cord includes a two-layer stranded construction including a core in which two or three core filaments are twisted, and including a one-layer outer sheath in which outer sheath filaments are helically wound around the core and along a longitudinal direction of the core. The core filaments have same filament diameters as the outer sheath filaments, length of lay for the core is same as length of lay for the outer sheath, and length of lay/filament diameter, which indicates a ratio of length of lay to a filament diameter, is between 50 and 75. Two or more filaments selected from among the core filaments and the outer sheath filaments, are crimped filaments each including bent sections and non-bent sections that are repeatedly disposed along the longitudinal direction.

A pneumatic tire includes a belt having an intersecting belt with a wide belt layer, a narrow belt layer, and a reinforcing layer between the wide belt layer and the narrow belt layer. A widthwise inner end of the reinforcing layer is on an inner side of the narrow belt layer, a widthwise outer end of the reinforcing layer is on an outer side of the narrow belt layer but on the inner side of the wide belt layer; core-sheath type composite fibers, whose core portion is composed of a high-melting-point resin having a melting point of 150 C. or higher and sheath portion composed of resin material containing an olefin-based polymer having a melting point not higher than tire vulcanization temperature, are embedded in the reinforcing layer; and an angle of the core-sheath type composite fibers is substantially the same as a reinforcing cord of the narrow belt layer.

Crown of a tire for a heavy vehicle that is desensitized to attacks. The tire (1) comprises tread (2) having a median degree of surface siping TL.sub.C, expressed in m/m.sup.2, equal to the ratio between the cumulative length L.sub.DC of the cuts (21), present in a median portion of tread of axial width W.sub.C, and the median area A.sub.C of the radially outer surface (23) of the tread (2), and protective reinforcement (4) comprising at least two protective layers (41, 42) that are formed of elastic metallic reinforcers and have a maximum breaking strength R.sub.max, expressed in daN/m, such that the median degree of surface siping TL.sub.C of tread (2) is at least equal to 5 m/m.sup.2 and a coupling ratio C.sub.C, equal to the ratio between the maximum breaking strength R.sub.max and the median degree of surface siping TL.sub.C, is at least equal to 18 000 daN.

Provided is a heavy load tire that includes: the first belt layer including a cord extending in the tire circumferential direction; the second belt layer including a cord extending to be inclined with respect to the tire circumferential direction; and the third belt layer including a cord extending to be inclined at an angle of 30 or less with respect to the tire circumferential direction in a direction opposite to that of the cord of the second belt layer. The first, the second, and the third belt layer are arranged in the stated order from the inner side to the outer side in the tire radial direction. The third belt layer has a width w.sub.3 that is 80% or more of a tread width w, and the second belt layer has a width w.sub.2. The width w.sub.2 and the width w.sub.3 satisfy the relation w.sub.2<w.sub.3.