Abstract: A wire (10) is disclosed. Said wire (10), when viewed in cross-section, has at least one first portion (12) and at least one second portion (14) that are interconnected by a third portion (16) in which the wire (10) has a reduced cross-section.

Abstract: In one aspect, a method of manufacturing a protective textile may include steps of (a) twisting a first yarn with a tungsten filament; and (b) using a second yarn to cover the yarn-tungsten product generated in step (a). The yarn generated in step (b) is further twisted with an elastic spandex. In one embodiment, the first yarn is selected from a group of Nylon, Polyethylene Terephthalate (PET), cotton yarn, bamboo fiber and Tencel. In another embodiment, a Polyethylene (PE) fiber is the second yarn, and the third yarn may include Nylon, PET or PE. The protective textile is advantageous because it is light, thin, soft and highly cut resistant. Also, it has great electrical conductivity and chemical stability, and it is not easy to deform after washing.

Abstract: An apparatus for producing an assembly of filamentary elements that are wound together in a helix includes a twisting device, a preforming device, and an assembling device. The twisting device is structured to twist at least first and second filamentary elements individually, such that each filamentary element is twisted separately from another filamentary element, to produce at least first and second twisted filamentary elements. The preforming device, which is arranged downstream of the twisting device, is structured to preform each of the twisted filamentary elements individually into separate preformed helixes, to produce at least first and second preformed helixes. The assembling device, which is arranged downstream of the preforming device, is structured to assemble the preformed helixes into an assembly.

Abstract: Provided is a steel cord for reinforcing rubber articles which, when applied to a belt of a tire, can attain lightweight without reducing the durability of the tire, and in particular, to a steel cord for reinforcing rubber articles in which the properties of a treat after rubberizing are excellent and a pneumatic radial tire using the same. Also provided is a steel cord for reinforcing rubber articles comprising a core formed by arranging two core filaments 1 in parallel without being twisted together, and N (2?N?4) sheath filaments 2 which are twisted together around the core. Letting the diameter of the core filament 1 be d1, and the diameter of the sheath filament 2 be d2, d1>d2.

Abstract: A steel cord (10) adapted for the reinforcement of elastomeric products comprises a core strand (12) and a layer of outer strands (14) arranged around the core strand (12). The core strand (12) comprises a core and at least a layer arranged around the core. The core further comprises one to three core filaments and the layer further comprises three to nine layer filaments. The core strand (12) has a first wave form and each filament of the outer strands (14) has a second wave form such that the first wave form is substantially different from the second wave form. This allows to guarantee full rubber penetration.

Abstract: A stranding apparatus including a preformer attached to a preformer shaft; an adjustable core guide attached to the preformer shaft; and a ring positioned away from the preformer and centered on a longitudinal axis of the preformer shaft; wherein a gap is formed between the ring and the adjustable core guide, through which a stranding element can pass.

Abstract: A steel cord (30) with a high elongation at break of at least 5% comprises n strands (20), each of said strands (20) has m filaments (10) twisted together, n ranges from 2 to 7. m ranges from 2 to 9. The strands and the filaments are twisted in a same direction. The lay length of the cord is Lc and the lay length of said strand is Ls. The ratio of Ls to Lc (Ls/Lc) ranges from 0.25 to 1. Lc ranges from 16 mm to 26 mm. The strands are helically preformed. The E-modulus of the cord is more than 150000 N/mm2. The helical preforming of the strands allows to obtain a high elongation at break and a high E-modulus despite its long lay length Lc.

Abstract: A steel cord (10) adapted for the reinforcement of rubber products, the steel cord (10) comprises a core (12) and three or more outer strands (14) twisted around the core (12) in a cord twisting direction. The outer strands (14) comprise outer filaments (16) twisted in a strand twisting direction which is the same as the cord twisting direction. The outer strands (14) have a wavy form which makes spaces between the core (12) and the outer strands. The steel cord (10) has improvements on elongation at break and impact resistance capacity.

Abstract: A two-layer cord having a number of wires in the outer layer, enclosing, but not completely, a cord core formed by a plurality of core wires, and in which the core wires are not preformed, while at least some of the outer wires are preformed.

Abstract: A steel cord (50) comprises a core layer and an outer layer. The core layer comprises a number of first steel filaments (10) and the outer layer comprises a number of second steel filaments (20). The outer layer is helically twisted around the core layer. The first steel filaments have a twisting pitch greater than 310 mm. At least one of the first steel filaments (10) is wavy preformed in one plane. At least one of the second steel filaments (20) is polygonally preformed.

Abstract: A termination for an end of a braid formed as a flat closed loop of braided strands expandable to an annular cylinder having a selected wall thickness includes a sleeve having a selected internal diameter. Spacers are configured to be applied on the braid such that when in contact with each other form an annular cylinder having an external diameter selected to fit inside the sleeve. The spacers have a bevel at one longitudinal end. A substantially cylindrical insert has a bevel at one longitudinal end at substantially a same bevel angle as on the spacers. A diameter of the insert combined with twice the wall thickness of the braid is larger than an internal diameter the spacers. When axial tension is applied to the braid, the bevel on the insert with braid thereon laterally urges the spacers outward. The sleeve limits lateral outward movement of the spacers.

Abstract: A metal cord includes at least one preformed elementary metal wire. The metal cord has an elongation at break, measured on the bare cord, higher than or equal to 3%, preferably 4% to 6%; an elongation at break, measured on the rubberized and vulcanized cord, which differs in an amount not higher than or equal to 15%, preferably 2% to 10% with respect to the elongation at break measured on the bare cord; a part load elongation, measured on the bare cord, higher than or equal to 0.4%, preferably 0.5% to 1.5%; a part load elongation, measured on the rubberized and vulcanized cord, which differs in an amount not higher than or equal to 15%, preferably 0.5% to 10%, with respect to the part load elongation measured on the bare cord.

Abstract: The present invention relates to an electrically conductive metal composite embroidery yarn and embroidered circuit using thereof which may be applicable to smart textiles. More particularly, this invention relates to an electrically conductive metal composite embroidery yarn and embroidered circuit for smart textiles which can be used as power supply and signal transmission lines. The present invention provides an embroidered circuit which consists of a metal composite embroidery yarn and a dielectric fabric substrate, wherein the electrically conductive metal composite embroidery yarn is embroidered on the dielectric fabric substrate to form a circuit.

Abstract: The durability is improved by using as a carcass ply cord or a belt cord of a tire a cord formed by twisting plural steel filaments having a tensile strength of not less than 2700 N/mm2, and a total elongation at break of the cord of 3.0-7.0% without sacrificing the excellent ride comfort.

Abstract: A metal cord includes at least one preformed elementary metal wire. The metal cord has an elongation at break, measured on the bare cord, higher than or equal to 3%, preferably 4% to 6%; an elongation at break, measured on the rubberized and vulcanized cord, which differs in an amount not higher than or equal to 15%, preferably 2% to 10% with respect to the elongation at break measured on the bare cord; a part load elongation, measured on the bare cord, higher than or equal to 0.4%, preferably 0.5% to 1.5%; a part load elongation, measured on the rubberized and vulcanized cord, which differs in an amount not higher than or equal to 15%, preferably 0.5% to 10%, with respect to the part load elongation measured on the bare cord.

Abstract: A tire for a vehicle wheel includes at least one metallic reinforcing cord comprising a single strand of elementary filaments preformed by sinusoidal waving and wound together. The number of filaments is greater than or equal to 3 and less than or equal to 8. A diameter of each filament is greater than or equal to 0.12 mm and less than or equal to 0.35 mm. A linear density of the at least one reinforcing cord is greater than or equal to 0.18 g/m and less than or equal to 4.0 g/m. A value of a breaking-stress integral of the at least one reinforcing cord is greater than or equal to 5,000 J/m3. In a two-wheeled vehicle, the at least one reinforcing cord in a tire for front-mounting may be distributed with a variable density while, in a tire for rear-mounting, the density may be constant.

Abstract: A pneumatic tire includes metal cords each made of metal filaments twisted together, the metal cords having an initial elongation in a range of from 0.05 to 0.20% and a standard deviation of the initial elongation in a range of not more than 0.02. A method of manufacturing the metal cord comprises shaping metal filaments in a two-dimensional zigzag waveform, and twisting the shaped metal filaments together, wherein the number of the filaments is in a range of from 8 to 12, the metal filaments have the same diameter (d) of from 0.15 to 0.30 mm, the shaped metal filaments have the same zigzag waveforms, the zigzag waveform of each said shaped metal filament has constant wave lengths (P) and constant wave heights (h) wherein the ratio (P/d) is in the range of 100/3 to 700/3, and the ratio (h/d) is in the range of 5/3 to 80/3.

Abstract: A machine for manufacturing a cord consisting of twisted metallic wires comprises a pair of crimping wheels with meshing toothed surfaces for crimping a plurality of wires when they are passed between said meshing toothed surfaces, and a twisting means for twisting together the wires along a twisting path downstream of the pair of twisting wheels. The pair of crimping wheels is arranged at the beginning of the twisting path and the twisting together of the wires preferably starts between the meshing toothed surfaces.

Abstract: A method for making strings for sport rackets includes a step of extruding two wires of different materials and a step of twining the two wires along an axis to form a string. The string includes a core wire of a first material and a sun-wire of a second material is twined to the core wire. No acid-wash is needed and the two steps can be completed within one machine.

Abstract: A zero degree tire reinforcing steel cord is formed by twisting together four to seven individual wires having a wire diameter of 0.20 to 0.45 mm, wherein the steel cord has a substantially spiral or a substantially planar wavy deformation, has an elongation of 1.2% to 2.0% under a tensile load of 50 N and becomes substantially linear with its wavy deformation disappearing under a tensile load of 50 to 250 N. The steel cord stretches to a moderate extent so as to track expansion of the tire in the radial direction during the vulcanization process and thereafter restrains expansion of the tire in the radial direction during continued high speed rotation of the tire.

Abstract: A metal cord for reinforcing rubber articles and a pneumatic tire including metal cords to reinforce tire components such as carcass, breaker and band are disclosed, wherein a metal cord according to one aspect of the present invention comprises filaments having a tensile strength of from 4000 to 5500 N/sq.mm and a diameter of from 0.10 to 0.35 mm and the filaments are twisted together, the filaments before twisted are two-dimensionally waved so that the elongation after fracture of the cord becomes in a range of from 2 to 6%. According to another aspect of the present invention, the metal cord is a single filament having a tensile strength of from 4000 to 5500 N/sq.mm and a diameter D of from 0.10 to 0.35 mm, and the filament is two-dimensionally waved so that the elongation after fracture becomes in a range of from 2 to 6%.

Abstract: A unidirectional three dimensional fiber structure is provided which does not require weaving, displays a high level of interlayer strength and does not suffer from cracking, and which can also be easily produced with any arbitrary cross-section. A unidirectional three dimensional fiber structure is produced by inserting a plurality of long fibers which have been aligned unidirectionally into an inlet at one end of a cylindrical die with a plurality of needle holes in the peripheral walls thereof, and then performing needlepunch through the needle holes while drawing the plurality of long fibers out from an outlet at the opposite end of the cylindrical die.

Abstract: A steel cord is composed of three to six steel filaments each having a filament diameter of from 0.25 to 0.45 mm, the three to six steel filaments including shaped filaments and twisted together, wherein the shaped filaments are, before twisted together, coiled to be set in a form of coil having a coil diameter of less than 5 mm and a coil pitch of more than 5 mm, the shaped filaments include at least two kinds of shaped filaments which are different in respect of the form of coil, the shaped filaments are twisted together while the coil diameter is reduced, the elongation of the cord at 50 N load is less than 0.2%, and the cord strength is in a range of from 2500 to 3500 N/sq.mm.

Abstract: Steel cord includes a first group and a second group. The second group is helically twisted around the first group with a cord twisting step. The first group includes a first number of first steel filaments. The first number ranges between three and eight. The second group comprises a second number of second steel filaments. The second number is equal to or greater than the first number. The first filaments having a twist step greater than 300 mm. At least one of the second filaments is polygonally performed in order to allow rubber penetration.

Abstract: A device re-shapes formed wire after processes such as annealing where wire is wound on bobbins. The device includes a reservoir for containing lubricant having a first open end and a second open end. The first end of the reservoir is closed by a guide mechanism for guiding the wire into the reservoir. The second end of the reservoir is closed by a wire shaping for shaping the wire when the wire is pulled therethrough. The wire shaping mechanism reduces the cross-sectional area of the wire by no more than 24%.

Abstract: A tire for a vehicle wheel, includes a torus-shaped carcass, a tread located on a periphery of the carcass, and a pair of axially-facing side walls ending with beads reinforced with bead wires and respective bead-filling elements for mounting the tire on a corresponding rim. The tire includes rubberized fabrics reinforced with metal reinforcing cords. At least one of the metal reinforcing cords comprises at least two wires helicoidally double-twisted around a longitudinal axis of the metal cord. Further, at least one of the wires is permanently deformed by a substantially-sinusoidal deformation lying in a plane.

Abstract: A metallic cord is composed of metallic filaments gathered together, the metallic filaments include at least one patterned filament which is, before gathered together, two-dimensionally waved so as to have a wave form defined by plural kinds of cycles different from each other in respect of the wave length and/or wave height. A pneumatic tire includes the metallic cords as its carcass cords.

Abstract: The invention improves rubber permeability while making a cord diameter compact. A metal cord is constituted by a layered structure having a core comprising totally 6 to 12 filaments sectioned into 1 to 4 filament bundles, and a sheath comprising 8 to 15 filaments arranged around the core. Each of the filament bundles includes a waved filament modeled in a two-dimensional wave shape and a non-waved filament, in a state before being bundled. The core makes the wave of the waved filament three-dimensional within the core by applying torsion to each of the filament bundles.

Abstract: A process for manufacturing a metal cord includes the steps of permanently deforming at least one wire using a substantially sinusoidal deformation lying in a plane and stranding the at least one wire together with one or more other wires by helicoidally double twisting the wires around a longitudinal axis of the metal cord. The metal cord may include at least two wires each with diameter greater than or equal to 0.10 mm and less than or equal to 0.50 mm. An associated metal cord includes at least two wires. One or more of the at least two wires is permanently deformed using a substantially sinusoidal deformation lying in a plane. The at least two wires are stranded together by helicoidally double twisting the at least two wires around a longitudinal axis of the metal cord.

Abstract: A pneumatic tire comprises a tread reinforcing belt made of metallic cords, each of the metallic cords is made up of six to twelve metallic filaments whose diameter is not less than 0.15 mm but less than 0.25 mm, the six to twelve metallic filaments are grouped into a plurality of bunches each including two to four filaments, the filaments of each bunch are twisted together at a first twisting pitch, the bunches are twisted together into the cord at a final twist pitch Pc of from 10 to 40 mm, the first twisting pitch is more than the final twist pitch, and the bunches each include at least one waved filament which is two-dimensionally waved at wave pitches Pw in a range of from 5 to 30 times the diameter (d) of the filament and a wave height (h) in a range of from 0.2 to 3.0 times the diameter (d).

Abstract: The invention relates to a false twister (10), especially for producing spiral filaments. The false twister comprises a rotatably driven twister (17) with at least one guide roller (18) around which the filaments (11) are wrapped. The aim of the invention is to reduce the forces that act upon the spiral filaments (11′). To this end, at least one guide roller (18) is driven. According to a method for producing spiral filaments (11) the power necessary for moving the filaments (11) through the false twister (10) is at least partially applied on the filaments (11) in the false twister (10).

Abstract: A steel cord is composed of three to six steel filaments each having a filament diameter of from 0.25 to 0.45 mm, the three to six steel filaments including shaped filaments and twisted together, wherein the shaped filaments are, before twisted together, coiled to be set in a form of coil having a coil diameter of less than 5 mm and a coil pitch of more than 5 mm, the shaped filaments include at least two kinds of shaped filaments which are different in respect of the form of coil, the shaped filaments are twisted together while the coil diameter is reduced, the elongation of the cord at 50N load is less than 0.2%, and the cord strength is in a range of from 2500 to 3500 N/sq.mm.

Abstract: A metal cord for reinforcing rubber articles and a pneumatic tire including metal cords to reinforce tire components such as carcass, breaker and band are disclosed, wherein a metal cord according to one aspect of the present invention comprises filaments having a tensile strength of from 4000 to 5500 N/sq.mm and a diameter of from 0.10 to 0.35 mm and the filaments are twisted together, the filaments before twisted are two-dimensionally waved so that the elongation after fracture of the cord becomes in a range of from 2 to 6%. According to another aspect of the present invention, the metal cord is a single filament having a tensile strength of from 4000 to 5500 N/sq.mm and a diameter D of from 0.10 to 0.35 mm, and the filament is two-dimensionally waved so that the elongation after fracture becomes in a range of from 2 to 6%.

Abstract: Device for manufacturing metal cords to be used particularly for reinforcing composite elastomeric products, comprising: a supporting structure (100); a rotor (5) engaged with respect to said supporting structure (100) and rotatable according to a predefined axis; a cradle fastened to said supporting structure (100) according to an oscillation axis which coincides with the rotation axis of the rotor (5); feeding devices operatively fitted on said cradle to feed several elementary wires from the respective feeding spools (8), said elementary wires being driven onto said rotor (5) according to a stranding path with and sections (10A, 10C) coinciding with the rotation axis of the rotor (5) and with a central section (10B) distanced from said rotation axis; at least one preforming device (15) operatively engaged with the cradle and operating on one of said elementary wires in a section upstream with respect to the first end section (10A) of the stranding path.

Abstract: A machine for manufacturing metal cords includes a supporting structure, a rotor engaged with respect to the supporting structure, a cradle fastened to the supporting structure, feeding devices operatively fitted on the cradle to feed a plurality of elementary wires from respective feeding spools, and at least one preforming device operatively engaged with the cradle and operating on at least one of the elementary wires in a section upstream with respect to a first end section of the stranding path. The elementary wires are driven onto the rotor according to a stranding path. The stranding path has end sections coinciding with the rotation axis of the rotor and a central section distanced from the rotation axis of the rotor. The at least one preforming device provides the at least one of the elementary wires a substantially sinusoidal deformation lying in a plane.

Abstract: Disclosed herein are a tire-reinforcing steel cord and a pneumatic radial tire using the same. The tire-reinforcing steel cord includes an inner layer consisting of 3 filaments and an outer layer consisting of 7 or 8 filaments and surrounding the inner layer. The inner layer and the outer layer are twisted in such a manner that they have the same twist direction and the same twist pitch length, whereby the number of the twisting steps in the manufacture of the steel cord is reduced, and also the penetration of rubber into the steel cord is improved such that the steel cord has an improved durability upon application to tires.

Abstract: A method and a device for facilitating the sliding, along a track, of an element having a predominant axial dimension subjected to an intense force pressing it against the track, particularly for facilitating the sliding of a wire subjected to stranding in stranding machines. The method consists in interposing between the element and the track a pressurized fluid which contrasts the force that presses the element against the track. In this way, the sliding friction of the element on the track is reduced and it is possible to reduce the force to be applied to the element in order to achieve its advancement along the track.

Abstract: Steel cord is manufactured by: forming a plurality of bends, per filament length equivalent to one twist pitch, on each of filaments which constitute an outer layer sheath, with the filament length equivalent to one twist pitch being a cycle; twisting these filaments while the bends belonging to the same phase are aligned in a cord axial direction; and subjecting cord side surfaces to compression processing. As a result, flat side surface portions are formed, in which a plurality of filaments forming the outer layer sheath are positioned substantially in the same plane. The steel cord thus formed is used in reinforcement plies for pneumatic radial tires such that the reinforcement plies are laminated in a manner in which the flat side surface portions are mutually parallel.

Abstract: A rubber reinforcing steel cord of a bundle-twisted+layer-twisted structure obtained by arranging 9 steel filaments around 3 steel filaments each being two-dimensionally wave-like shaped in the lengthwise direction, intertwining all of these steel filaments in one operation to form a bundle-twisted cord, and further arranging 14 steel filaments around the bundle-twisted cord followed by intertwining. Also, a heavy duty pneumatic radial tire using the rubber reinforcing steel cord as the cord of the carcass layer thereof.

Abstract: A machine for manufacturing metal cords includes a supporting structure, a rotor engaged with respect to the supporting structure, a cradle fastened to the supporting structure, feeding devices operatively fitted on the cradle to feed a plurality of elementary wires from respective feeding spools, and at least one preforming device operatively engaged with the cradle and operating on at least one of the elementary wires in a section upstream with respect to a first end section of the stranding path. The elementary wires are driven onto the rotor according to a stranding path. The stranding path has end sections coinciding with the rotation axis of the rotor and a central section distanced from the rotation axis of the rotor. The at least one preforming device provides the at least one of the elementary wires a substantially sinusoidal deformation lying in a plane.

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: Method and machine for stranding two conductors, as two helices offset by a half stranding length in the same winding direction, without turning the conductors about respective axes thereof. The machine includes an arch-type stranding assembly which dispenses the two conductors so that one revolves around the other, a first support located at the exit of the arch-type stranding assembly to provide first contact points for the conductor proximate to a main rotation axis about which a conductor nrevolves around the other, second supports located downstream of the first support along the advancement direction of the two conductors and providing second contact points for the two conductors, and a die located downstream of the second supports to complete the pairing of the conductors. The first support and second supports revolve jointly with a first one of the conductors around the main axis.

Abstract: Rotating winch for stranding lines comprising a hollow rotor (1) wherein a motor (9) suitable for rotating a drawing drum (12) around an axis perpendicular to the axis of rotation of the rotor (1) is arranged, the external lateral surface (21) of said drawing drum (12) having a substantially concave profile which is included between two containment walls (22, 22′). Said profile is preferably symmetrical and has a substantially constant radius of curvature, equal to about the double of the distance between the containment walls (22, 22′) and to about ⅔ of the external diameter at the center of the drawing drum.

Abstract: The present invention relates to a method and an apparatus for manufacturing a steel cord. A method according to the present invention comprises the steps of: combining a plurality of the steel filaments supplied from the bobbin by means of the guide rollers; applying a twist pattern to the combined filaments by rotating a pair of flyers arranged between a pair of turn rollers in the counterclockwise direction, and advancing them; applying a further twist pattern to the advanced cord by rotating another pair of flyers arranged between another pair of turn rollers in the reverse direction; stabilizing the cord by means of the overtwist; and winding the resulted cord. The method and apparatus for manufacturing the steel cord have effects that productivity can be improved up to two times or six times even with the same revolution, as compared with the manufacturing apparatus of the prior art.

Abstract: For reinforcing rubber or plastics articles, particularly pneumatic tires, a wire filament is proposed which is spirally shaped and exhibits no elastic residual torsional stresses. A wire filament 8 according to the invention is produced by twisting drawn straight wire filaments 2 into the range of plastic deformation with subsequent return-twisting, at least two wire filaments being brought together and combined prior to return-twisting. Preferably at least two wire filaments 2 are brought together by means of a perforated disk 30, twisted about each other and plastically deformed in a false twister 20 and subsequently return-twisted in a further false twister 40.

Abstract: A steel cord according to this invention comprises 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 corrosion resistant steel cord for reinforcing rubber articles, particularly a belt and/or carcass of a pneumatic tire, has a residual compressive stress inside the twisting helix of each steel filament such that a ratio R.sub.1 /R.sub.0 is less than one, where R.sub.0 is the radius of curvature of a helix in each helically formed steel filament obtained by untwisting of the cord and R.sub.1 is the radius of curvature of the helix after removal of a surface layer from the inside of the helix in the steel filament. The steel filaments have a tensile strength of 4,000-4,800 N/mm.sup.2.

Abstract: A reinforcement ply for an elastomeric article comprises a plurality of parallel extensible reinforcing members laid at a substantially constant end count perpendicular to their longitudinal direction, the ply having different extensibilities in the longitudinal direction of the reinforcing members in different parts of the ply. The reinforcing members are preferably made such that they each have at least one filament which is displaced perpendicularly from the longitudinal centerline of the reinforcing member in one part of the reinforcing member compared to another part. A tire may include the reinforcement ply as a hoop or band in the ground contacting tread region.

Abstract: A heavy duty pneumatic tire comprises a belt disposed radially outside a carcass and radially inside a tread portion, the belt comprising at least one ply of at least one high-elongation steel cord, the high-elongation steel cord being formed by twisting at least three waving steel filaments together to form a core and a sheath surrounding the core. The waving 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, thereby defining a plurality of first parts with the core and a plurality of second parts without the core which are disposed alternately in the longitudinal direction of the cord. The elongation at break of the high-elongation steel cord is in the range of from 4 to 10%.

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.