Abstract: A steel cord (10) adapted for the reinforcement of elastomeric products comprises a core and a layer arranged around the core. The core comprises one to four core filaments (12) and the layer comprises three to ten layer filaments (14). At least one of the core filaments (12) have a first wave form and at least one of the layer filaments (14) have a second wave form such that the first wave form is substantially different from said second wave form.This allows to control the size of the micro-gaps and to guarantee rubber penetration.

Abstract: The steel wire is made using a carbon steel wire rod material containing 0.70 to 0.75 wt % carbon and has the characteristics that its diameter is 0.10 to 0.40 mm and Y.gtoreq.-1960d+3580 ?Y: tensile strength (N/mm.sup.2), d: diameter (mm)!. Furthermore, the torque decrease factor of the steel wire is less than 7% in a torsion-torque curve in a torsion-torque test wherein forward twisting and then reverse twisting are applied. A preferred steel cord has two steel wires bundled together substantially in parallel and one steel wire is wound around this bundle. This steel cord is made from steel wires having the diameter, tensile strength and toughness characteristics set forth above, and also the ratio B/A of the strength B of the twisted steel cord to the aggregate strength A of the steel wires before they are twisted together into the steel cord is 0.935 or over.

Abstract: A steel cord for reinforcing a rubber product includes a core consisting of one steel filament and a sheath consisting of a plurality of steel filaments wound around the core. The steel filament of the core alternately having straight portions, whose axes of the straight portions are disposed on one line, and protrusions formed by bending. The peak of each protrusion is disposed outside of the sheath. The steel cord for reinforcing a rubber product is used in a pneumatic tire. The pneumatic tire includes a carcass having a crown portion and having a toroidal shape, a pair of beads over which the toroidal shape extends, a belt layer or belt layers for reinforcing the crown portion of the carcass, and rubber surrounding the carcass, the pair of bead, and the belt layer(s). The steel cord is used in the carcass and/or the belt layer(s).

Abstract: A pneumatic radial tire includes a belt layer, comprised of steel cords having a lateral flat cross-section, arranged around an outer periphery of a tread portion of a carcass layer so that the diameter direction of the steel cords is made to follow the planar direction of the belt layer, the steel cord is made a flat 1.times.6 twist structure comprised of filaments of a filament diameter d of 0.20 to 0.40 mm, the long diameter D.sub.L and twist pitch P of the steel cord taken out from the tire are made with respect to the filament diameter d as follows:3.67 d-0.04.ltoreq.D.sub.L .ltoreq.3.67 d+0.1630d.ltoreq.P.ltoreq.45dand the elongation of the steel cord caused when increasing a load from 0.25 kg to 5.0 kg is made 0.25% or less.

Abstract: The steel wire for making steel cord used in rubber product reinforcement has a tensile strength, Y in N/mm.sup.2, such that Y.gtoreq.-1960d+3920, wherein d is the wire diameter in mm, and also a flat Vickers hardness distribution in a cross-section perpendicular to a length direction thereof from the surface to the interior, but excluding a central portion having a central portion diameter corresponding to 1/4 of the wire diameter. The steel wire is made by a method including wet drawing a carbon steel wire rod material containing 0.80 to 0.89% by weight carbon to a predetermined intermediate diameter and subsequently heat-treating and plating to form a final raw material and then wet drawing the final raw material to form the steel wire. The wet drawing steps are performed with drawing dies, each of which is provided with a drawing hole having a drawing hole diameter d.sub.1 and the drawing die has an approach angle 2.alpha. equal to from 8.degree. to 10.degree. and a bearing length of 0.3 d.sub.1.

Abstract: A steel cord (114) comprises strength elements (100, 132) and having a length, a longitudinal central axis (112) and a cord pitch. At least one of the elements (100) has a projection on a plane YZ perpendicular to the longitudinal central axis (112). This projection takes the form of a curve with a radius of curvature which alternates between a maximum and a minimum. The curve further has a center of curvature. The radius of curvature and the center of curvature lie inside the curve so that a convex curve is obtained. The cord (114) is further characterized by one or both of following features:(i) the distance between two minimum radii of curvature of said curve measured along the longitudinal central axis (112) is different from half the cord pitch; or(ii) if all of said elements (100) provide a convex curve, at least one of said convex curves substantially differs from another convex curve.

Abstract: A steel cord adapted for the reinforcement of an elastomer comprises steel filaments of a pearlitic structure. The steel cord has a plastic and elastic elongation at break of x % and a plastic and elastic elongation capability in the vulcanized elastomer of y %, the values x and y fulfilling following equation:y-0.50.ltoreq.x.ltoreq.y+0.50,which means that the total elongation at break does not fall down considerably after embedding the steel cord into an elastomer.

Abstract: The steel cord for reinforcement of an off-road tire has a superior resistance to penetration and durability with respect to sharp objects. It has a 3.times.3, a 3.times.4, a 4.times.3 or a 4.times.4 structure, an identical cord diameter at all points along the steel cord in a longitudinal direction, a cord lay length equal to from 3.5 to 7.5 times the cord diameter and an elongation at break of at least 4%. The steel cord is made up of element wires, each having a wire diameter of from 0.3 to 0.5 mm and a tensile strength of from 2000 to 3300 MPa.

Abstract: A tire cord which is improved in penetration of rubber into the cord and the fatigue resistance without increasing the diameter of the cord. The tire cord comprises a core and an inner sheath, the core consisting of three steel filaments twisted together, the inner sheath consisting of seven to nine steel filaments twisted around the core in the same direction as the core twist, the twist pitch length of the inner sheath being in the range of from 1.05 to 1.50 times the twist pitch length of the core, the diameter of the core filaments being in the range of from 0.8 to 1.0 times the diameter of the inner sheath filaments.

Abstract: A steel cord intended for use to reinforce rubber products is produced by drawing, into a steel filament of 0.10 to 0.40 mm in diameter and more than 3,000 N/mm.sup.2 in strength, a wire rod having a carbon content of more than 0.70% by weight, and twisting a plurality of such steel filaments together. Also a pneumatic tire is provided which employs in at least a portion of a reinforcing member thereof the steel cord improved in corrosion resistance and having an R.sub.1 /R.sub.0 ratio.times.100 which is less than 100, where R.sub.0 is the radius of spiral curvature of the spiraled steel filament resulting from untwisting said steel cord and R.sub.1 is the radius of spiral curvature of said steel filament of which the surface layer inside the spiral is removed by dissolving.

Abstract: A steel cord for reinforcing a rubber product has a multilayer structure consisting of two or more layers including a core, or a structure consisting of seven or more strands twisted in the same direction at the same pitch. In the steel cord, at least one of three strands that are successively adjacent to one another or that are in mutual contact is formed of two filaments that are paired substantially parallel to each other. The direction of pairing the two filaments of each strand is substantially the same over the entire length of the cord. Each of the remaining strands is formed of a single filament.

Abstract: The method for continuous production of a multifilament stretchable weft yarn for tire cord fabric includes swirling polyester-POY-filaments with an initial titre of from 170 to 260 dtex by means of a gas having a pressure of from 0.5 to 3 bar in a swirling nozzle, and immediately thereafter, shrinking with an overfeed of from 40 to 80% at from 220.degree. to 240.degree. C. for at least 0.2 sec to form a stretchable multifilament weft yarn. This weft yarn has a rough surface with non-slip properties, a tenacity of greater than 7 cN/tex, an elongation at break of from 170 to 270% and a thermal shrinkage at 160.degree. C. of from +2% to -2%, measured at 160.degree. C. during 15 minutes at a pretension of 0.1 cN/tex.

Abstract: A steel cord intended for use to reinforce rubber products is produced by drawing, into a steel filament of 0.10 to 0.40 mm in diameter and more than 3,000 N/mm.sup.2 in strength, a wire rod having a carbon content of more than 0.70% by weight, and twisting a plurality of such steel filaments together. Also a pneumatic tire is provided which employs in at least a portion of a reinforcing member thereof the steel cord improved in corrosion resistance and having an R.sub.1 /R.sub.0 ration.times.100 which is less than 100, where R.sub.0 is the radius of spiral curvature of the spiraled steel filament resulting from untwisting said steel cord and R.sub.1 is the radius of spiral curvature of said steel filament of which the surface layer inside the spiral is removed by dissolving.

Abstract: An endless power transmission belt construction, cord therefor and methods of making the same are provided, the cord having the yarns and the plies thereof respectively twisted on a 2 for 1 twister so as to cause the longitudinal axes of the fiber filaments to be disposed generally in the longitudinal direction of the cord with the denier of the fiber filaments of each yarn being approximately 1500. The twist multiplier of three plies is 3.7687 as the plies are twisted together at a rate of approximately 2.9 turns per linear inch of the cord, and the twist multiplier for the two yarns is 3.6765 as the two yarns for each ply are twisted together at a rate of approximately 4.9 turns per linear inch of that ply. The twist multiplier for five plies is 3.6986 as the plies are twisted together at a rate of approximately 1.8 turns per linear inch of the cord, and the twist multiplier for three yarns is 3.5838 as the three yarns for each ply are twisted together at a rate of approximately 3.

Abstract: A two-layered twisted steel cord for reinforcing rubber articles, comprising a core including two filaments and a sheath including six or seven filaments wound around the core, in which an average twist pitch of the core is set to be at least 30 mm, and when six filaments are used for the sheath, a ratio of diameter ds of each filament of the sheath to diameter dc of each filament of the core, ?(ds/dc).times.100!, is set in a range of 58.0 %<ds/dc<161.5%. When seven filaments are used for the sheath, the ratio of diameter ds to diameter dc is set in a range of 47.3%<ds/dc<121.1%. The two-layered twisted steel cords are used for reinforcing rubber articles, such as a pneumatic radial tire.

Abstract: The present invention relates to a steel cord comprising two core wires and five outer wires each having a diameter larger than that of each core wire and integrally twisted on the core wires, wherein a strand constituted by the five outer wires and the two core wires has an oblong cross-section.

Abstract: A cord comprising at least a first pair and a second pair of wires (2a, 2b) of different diameter randomly disposed in transverse cross section thereof, is obtained by arranging in a nacelle (7) of a double-twisting laying machine, a twister (16) operating upstream of a preformer (15). The twister (16), rotating in a direction opposite to that of the impeller (5) and at a speed which is twice that of the impeller, neutralizes the internal torsional stresses induced in the wires (2a, 2b) by effect of the double twisting carried out upon the action of the impeller itself. Thus, a better control of the preforming operation executed on the wires (2a, 2b) disposed parallel in respectively coplanar axes is enabled.

Abstract: A steel cord (10) for the reinforcement of timing belts or transmission belts comprises only two to five strands (12) tightly twisted with each other in a first direction at a cord twisting pitch. Each of said strands (12) comprises only two to seven steel filaments (14) tightly twisted with each other in this first direction at a strand twisting pitch. The steel filaments (14) have a diameter ranging from 0.03 to 0.40 mm. The ratio strand twisting pitch to filament diameter is greater than 30, the ratio cord twisting pitch to filament diameter is greater than 30, and the ratio cord twisting pitch to strand twisting pitch is greater than 1. Such a steel cord has an acceptable low torsion moment under axial loads.

Abstract: The pneumatic tire has a single carcass ply reinforced with parallel metallic cords, each cord composed of at least one filament having a tensile strength of at least (-2000.times.D+4400 MPa).times.95%, where D is the filament diameter in millimeters. The turnup portion of the single carcass ply 12 in the bead portion of a pneumatic tire is interposed between the bead core 11 and a toe guard 18, and the radially outer edge of each turnup portion being in contact with the main portion of the carcass ply and extending to an end point 0.5 to 4.0 inches (12.7 to 101.6 mm) radially outward of the bead core. The toe guard 18 has a first and second end and each end is disposed directly adjacent to the carcass ply. The first end 18a of the toe guard is located on the axially inner side of the main portion of the carcass ply at a location about 0.4 to 3.

Abstract: A pneumatic tire comprises a carcass toroidally extending between a pair of bead portions and a belt arranged outside the carcass in a radial direction of the tire and composed of at least one belt layer, in which the belt layer is made from a plurality of steel cords, each cord being formed by twisting 2 to 4 filament bundles each consisting of two steel filaments paralleled with each other so as to have a structure that major axes of the filament bundles constituting the cord are set toward substantially the same direction. In the belt layer, the major axes of the filament bundles in the cords constituting the belt layer are arranged substantially in a row in a widthwise direction of the belt.

Abstract: A steel cord (10) comprises eight or more strands (12, 14) twisted together. Each of the strands has a substantially same cord twisting direction and a substantially same cord twisting pitch in the steel cord, and each of the strands consists of two to five individual filaments (16, 18) twisted together. Such a multi-strand steel cord can be manufactured without having to twist the individual strands separately and beforehand.

Abstract: A steel cord is disclosed, which has a core-sheath double layer structure having a 2+7 cord construction or a 2+8 cord construction. A twisting direction of the core is the same as that of the sheath, a forming rate Rc of filaments of the core is 103 to 120%, and a forming rate Rs of filaments of the sheath is 102 to 115%. A pneumatic radial tire using such steel cords in a belt layer is also disclosed.

Abstract: A pneumatic tire has organic fiber carcass cords. The organic fiber carcass cords comprise double-twisted fiber yarns and satisfy the following equations. ##EQU1## where D.sub.1 is the original denier, D.sub.2 is the total of the original denier, N.sub.1 is a ply-twisting coefficient, N.sub.2 is a cable-twisting coefficient, n.sub.1, is the ply-twisting number (turns/10 cm), n.sub.2 is the cable-twisting number (turns/10 cm) and .rho. is the specific gravity of the organic fiber.

Abstract: A steel cord (30) consists of a first group and a second group. The first group comprises two or more plastically deformed outer steel filaments (10) twisted around each other with a first twist pitch and the second group comprises one or more plastically deformed inner steel filaments (20) twisted around each other with a second twist pitch. The second group is twisted around the first group with a cord twist pitch. One of the inner or the outer steel filaments having a part load elongation of x %, all the other inner and outer steel filaments having a part load elongation of y %, whereby x and y fulfil the equation:x-0.10.ltoreq.y.ltoreq.x+0.10,and where all the inner and outer steel filaments have a deforming pitch that is substantially equal to the cord twist pitch.

Abstract: A metallic cord for the reinforcement of elastomers comprising seven strands of two filaments wherein one strand is surrounded by six strands and the six strands are twisted in the same direction and have the same lay length.

Abstract: A steel cord effective for reinforcing a super-large off-road tire wherein strands made by simultaneously twisting together 3 to 6 steel wires in the same twisting direction with the same pitch length are used and the steel cord is made by twisting together 3 to 6 such strands in the same direction as the twisting direction of the strands and with the same pitch length. Each of the steel wires constituting the strands continuously has a small wavy pattern of a pitch length smaller than the lay length of the strands and therefore each of the strands has a compound pattern comprising a wavy pattern formed by the twisting and said small wavy pattern and in a gap is formed between steel wires each of the strands by the small wavy pattern. The lay length P.sub.1 of the steel cord is 8 to 15 times the steel cord diameter D and the elongation on breakage by tension of the steel cord is over 5%.

Abstract: A wire, generally made of steel and used to make composite elements of elastomeric material, is submitted to an electrodeposition process in an electrolytic bath for being coated with a zinc/cobalt alloy in which the average cobalt content is lower than 1%. In the coating thickness made of the zinc/cobalt alloy, different cobalt concentrations exist, that is a 1% to 3% concentration at the area close to the metal and a concentration as low as 0.5% maximum at the overlying area. Adhesion promoters for example consisting of cobalt neodecanate, added to the elastomeric material, promote the adhesion of said elastomeric material to the wire.

Abstract: A steel cord for reinforcing rubber articles comprises one wave-form or helical core steel filament and five to eight sheath steel filaments disposed around the core steel filament, the pitch Pc of the core steel filament is 3.0 dc/0.34.ltoreq.Pc.ltoreq.10.0 dc/0.34 (dc=diameter of steel core filament) and the core forming ratio Rc=Lc/dc (Lc is an amplitude of the wave or helix of the core steel filament) is within a particular range varying depending on the number of sheath steel filaments. A pneumatic tire contains a cross belt reinforced with the above-mentioned steel cords where(i) an angle .theta. formed by the reinforcing steel cords and the equatorial plane of the tire is:12.degree..ltoreq..theta..ltoreq.30.degree.(ii) a gap between any two adjacent steel cords in the same layer of the cross belt, I, is:0.5 mm.ltoreq.I.ltoreq.2.0 mm(iii) a gauge of the gum between any two facing steel cords in different layers of the cross belt, G, is:0.35 mm.ltoreq.G.ltoreq.2.0 mm.

Abstract: A steel cord for the reinforcement of rubber articles exhibits largely different bending rigidities in two crossing directions at section of the cord and comprises a bundle of plural strands each being obtained by twisting 3 or more steel filaments and a wrapping filament helically wound around the bundle. The steel filaments have a twisting pitch in the range of 3.0 to 30.0 mm. A single wrapping filament is helically wound around the bundle at a twisting pitch of 2.0-15 mm. Various cord structures may be used, for example, 1.times.3, 1.times.5, 2+6 and 3.times.4.

Abstract: A high elongation compact helical steel cord with a high degree of elongation at break of not less than 5% has a (1.times.n) structure comprising three or more base wires which are helically preformed at a predetermined pitch and which are twisted in the same direction and at the same pitch so that the ratio P/D of the cord diameter D to the twisting pitch P is in the range of 8-15 with the base wire preforming pitch being shorter than the cord twisting pitch. The finished cord has a helical composite structure with its elongation under a load of 35 kgf/mm.sup.2 being 0.71%-1.00% and that under a load of 70 kgf/mm.sup.2 being 1.18%-1.57%. A radial tire is reinforced with the steel cord preferably as a steel belt cord. An apparatus for making the steel cord is provided with revolving preformers on the wire introducing portion of a bunching machine such that the bunching machine is rotated in a direction reverse to the rotational direction of the revolving preformers.

Abstract: A steel cord which is suitable for reinforcing a rubber product and has excellent fatigue resistance. The steel cord has a layer-twisted structure formed by steel filaments respectively having a diameter of 0.15 mm to 0.25 mm. A core of the steel cord is formed by 1 to 4 steel filaments. A least 6 steel filaments are wound around the steel filaments of the core to form at least one layer. When the steel cord is bent from a straight state to a state in which a radius of curvature thereof is d/(17.times.10.sup.-3) wherein d is a diameter in millimeters of each steel filament in an outermost layer of the steel cord, a maximum amount of movement of each steel filament in the outermost layer in a cross-section of the steel cord is less than or equal to (-0.5454d+0.1454).times.10.sup.3 um. The steel cord preferably has a two-layer-twisted structure or a three-layer-twisted structure, and has an arrangement in which the diameters of the steel filaments gradually decrease from the core to the outermost layer.

Abstract: An aramid monofilament having high mechanical properties is provided. This monofilament has a slightly structured skin and resists fibrillation and abrasion. In addition, a process for the production of this monofilament is also provided. The process includes the following steps: (i) a solution of aromatic polyamide(s) is extruded as a liquid jet in a spinneret through a capillary; (ii) the jet is drawn from the capillary in a non-coagulating layer of fluid and (iii) the drawn liquid vein is introduced into a coagulating medium in order to form the monofilament, which is subsequently washed, dried and contacted with a solvent for said monofilament to produce the slightly structured skin. The aramid monofilament is characterized by the following relationships:1.7.ltoreq.Ti.ltoreq.260;50.ltoreq.D.ltoreq.480;T.gtoreq.180-D/3;Mi.gtoreq.1600;Ar>2.00; andEr>20.0 D/30.In the above relationship, Ti represents linear density in tex, D represents diameter in .mu.

Abstract: A steel cord for the reinforcement of rubber article has a three-layer twisting construction comprising a core layer comprised of a single steel filament, a first sheath layer comprised of six steel filaments and a second sheath layer comprised of steel filaments subtracted by 1 or 2 filament from maximum steel filament number arranged on a circumscribed circle of the first sheath layer without a wrap filament. In this steel cord, filament diameters of the core layer and the sheath layers satisfy the particular relationships. The steel cord is used in a carcass ply of a heavy duty pneumatic radial tire.

Abstract: A metal wire, having a steel core and being provided with a layer of cladding of a zinc/manganese alloy containing between 5% and 80% of manganese. The wire is used as a reinforcement structure for tires or other products of elastomer material. Several embodiments of a process for applying the cladding on the steel core by electrodeposition of the zinc/manganese alloy are also described.

Abstract: A tire cord which is improved in rubber penetration. The cord has at least four filaments twisted together so as to form a core and a sheath surrounding the core. The filaments change place repeatedly along the longitudinal direction of the cord such that one of the filaments forms the core in a portion, but in a different portion of the cord, the same filament forms part of the sheath.

Abstract: A steel cord (114) comprises strength elements (100, 132) and having a length, a longitudinal central axis (112) and a cord pitch. At least one of the elements (100) has a projection on a plane YZ perpendicular to the longitudinal central axis (112). This projection takes the form of a curve with a radius of curvature which alternates between a maximum and a minimum. The curve further has a center of curvature. The radius of curvature and the center of curvature lie inside the curve so that a convex curve is obtained. The cord (114) is further characterized by one or both of following features:(i) the distance between two minimum radii of curvature of said curve measured along the longitudinal central axis (112) is different from half the cord pitch; or(ii) if all of said elements (100) provide a convex curve, at least one of said convex curves substantially differs from another convex curve.

Abstract: A steel cord for reinforcing rubber articles comprises one wave-form or helical core steel filament and five to eight sheath steel filaments disposed around the core steel filament, the pitch Pc of the core steel filament is 3.0 dc/0.34.ltoreq.Pc.ltoreq.10.0 dc/0.34 (dc=diameter of steel core filament) and the core forming ratio Rc=Lc/dc (Lc is an amplitude of the wave or helix of the core steel filament) is within a particular range varying depending on the number of sheath steel filaments. A pneumatic tire contains a cross-belt reinforced with the above-mentioned steel cords wherei) an angle .theta. formed by the reinforcing steel cords and the equatorial plane of the tire is:12.degree..ltoreq..theta..ltoreq.30.degree.(ii) a gap between any two adjacent steel cords in the same layer of the cross belt, I, is:0.5 mm.ltoreq.I.ltoreq.2.0 mm(iii) a gauge of the gum between any two facing steel cords in different layers of the cross belt, G, is:0.35 mm .ltoreq.G.ltoreq.2.0 mm.

Abstract: A steel cord effective for reinforcing a super-large off-road tire wherein strands made by simultaneously twisting together 3 to 6 steel wires in the same twisting direction with the same pitch length are used and the steel cord is made by twisting together 3 to 6 such strands in the same direction as the twisting direction of the strands and with the same pitch length. Each of the steel wires constituting the strands continuously has a small wavy pattern of a pitch length smaller than the lay length of the strands and therefore each of the strands has a compound pattern comprising a wavy pattern formed by the twisting and said small wavy pattern and in a gap is formed between steel wires each of the strands by the small wavy pattern. The lay length P.sub.1 of the steel cord is 8 to 15 times the steel cord diameter D and the elongation on breakage by tension of the steel cord is over 5%.

Abstract: A rubber article-reinforcing steel cord includes a core obtained by forming a single filament in a wavy shape, an inner sheath formed by arranging 5 to 6 filaments around the core, and an outer sheath formed by arranging 9 to 12 filaments around the inner sheath. The inner sheath and said outer sheath are twisted together. The diameter of each of the filaments of the inner and outer sheaths is not greater than that of the filaments of the core, 5d .ltoreq.L.ltoreq.3d and 1.2.ltoreq.H.ltoreq.d2.0d in which L and H are a wave length and a wave height of a wave shape of the waved filaments of the core, respectively, and d is a diameter of the filament of the core, and a ratio p.sub.3 /p.sub.2 between the twisting pitch p.sub.2 of the inner sheath and the twisting pitch p.sub.3 of the outer sheath is in a range of 1.4 to 2.5. A heavy duty pneumatic radial tire is also disclosed, which uses such steel cords in a belt.

Abstract: A method for producing a steel cord from 3 to 6 steel filaments on which a coating is applied to retain the adhesion to a rubber, the steel cord being destined for use to reinforce a rubber product having a flat section, comprising the following steps of preforming steel filaments at a ratio of more than 120% by twisting them together to form an open-structure steel cord; and passing the steel cord through a flattening apparatus provided at each of outlet and inlet thereof with a roller having a groove formed in the center of the circumference thereof, and between the inlet and outlet rollers with at least a roller of which the circumferential surface is flat, to repeatedly bend the steel cord vertically or horizontally.

Abstract: Tires using high tensile reinforcement with values of at least 1240N (280 lbs) for U+T type cord and at least 2000N (450 lbs) for bunched type cord.

Abstract: A steel cord for the reinforcement of rubber articles is formed by twisting plural filament wires of a high carbon steel. In this case, the filament wire is drawn from a wire rod so as to satisfy a relationship of T.gtoreq.230-148 logD (wherein D is a diameter of the filament wire and T is a tensile strength of the filament wire) and a difference in tensile strength between a surface layer portion and an internal portion in the filament wire of not more than 80 kgf/mm.sup.2.

Abstract: The steel cord has the 1.times.9 structure, in which three core wires and six thicker outer wires are twisted in the same direction with the same pitch, and has a flat shape in the section which is taken perpendicularly to the longitudinal section thereof. The six outer wires having at least two gaps between adjacent ones and the core wires have at least one gap between adjacent ones.

Abstract: A steel cord for reinforcing rubber articles and a pneumatic radial tire having a belt layer using the same, in which the steel cord comprises a core made of a steel filament wave-shaped in a plane (crimped) and turned (curled) and 5-8 sheath filaments wound around the core in the same direction as the turn direction of the core. The wavelength .lambda.c of the core is preferably defined as 8 dc.ltoreq..lambda.c.ltoreq.30 dc when the diameter of the core filament is dc, and the turn-number nc of the core around the center axis of the core per one wave-length of the core is preferably defined as 0.12.ltoreq.nc.ltoreq.0.85 (turn/pitch).

Abstract: A steel cord for the reinforcement of rubber articles exhibits largely different bending rigidities in two crossing directions at section of the cord and comprises a bundle of plural strands each being obtained by twisting 3 or more steel filaments and a wrapping filament helically wound around the bundle.

Abstract: A composite rubber body is formed by embedding steel cords in rubber and vulcanization-building them. In this case, each of the steel cords is a single steel filament wire or plural twisted steel filament wires obtained by drawing of a wire rod of high carbon steel having a given composition. The filament wires satisfy given relationships between filament diameter and tensile strength before and after the vulcanization and have a retention of loop strength of not less than 55%.

Abstract: A steel cord is disclosed, which has a core-sheath double layer structure having a 2+7 cord construction or a 2+8 cord construction. A twisting direction of the core is the same as that of the sheath, a forming rate Rc of filaments of the core is 103 to 120% and a forming rate Rs of filaments of the sheath is 102 to 115%. A pneumatic radial tire using such steel cords in a belt layer is also disclosed.

Abstract: A steel cord for the reinforcement of rubber articles comprises a core comprised of three steel filaments, a first sheath formed by twisting nine wave-formed steel filaments around the core, and a second sheath formed by twisting fifteen wave-formed steel filaments around the first sheath in a direction opposite to the twisting direction of the first sheath, in which a forming ratio F.sub.1 of each filament in the first sheath and a forming ratio F.sub.2 of each filament in the second sheath are within a range of 0.75-0.95, respectively, and satisfy Fi.sub.1 <F.sub.2.

Abstract: A steel cord (10) adapted for the reinforcement of elastomeric articles including a center structure of one to five center filaments (16) and a maximum of two layers of layer filaments surrounding said center structure: an outer layer of outer layer filaments (12, 13) and optionally, an intermediate layer of intermediate layer filaments (24) between the center structure and the outer layer. All the center filaments (16) and all the layer filaments (12, 13, 24) have the same twist hand and have the same twist pitch. The outer layer filaments (12, 13) exert a force which is directed radially inward.

Abstract: A steel cord for reinforcing rubber articles comprises one wave-form or helical core steel filament and a plurality of sheath steel filaments disposed around the core steel filament, the pitch Pc of the core steel filament is 3.0 dc/0.34.ltoreq.Pc.ltoreq.10.0 dc/0.34 (dc=diameter of steel core filament) and the core forming ratio Rc=Lc/dc (Lc is an amplitude of the wave or helix of the core steel filament) is within a particular range varying depending on the number of sheath steel filaments. The rubber articles containing the steel cord have an improved resistance to corrosion propagation and a high strength. A pneumatic tire is reinforced with the above-mentioned steel cord and contains a cross belt layer where(i) an angle .theta. formed by a reinforcing steel cord and the equatorial plane of the tire is:12.degree..ltoreq..theta..ltoreq.30.degree.(ii) a gap between adjacent two steel cords in the same layer, I, is:0.5 mm.ltoreq.I.ltoreq.2.0 mm(iii) a gauge of the gum between two facing cords, G, is:0.35 mm.