Pirelli Pneumatici S.p.a.

Pirelli Coordinamento Pneumatici S.p.a.

Omero Noferi

Marco Cipparrone

A vehicle wheel tire includes a carcass, a tread, a pair of side walls ending with beads for mounting the tire on a rim, a belt structure, and at least one breaker layer. The belt structure includes first, second, and third belts strips. The first and second belt strips each include metal cords parallel with respect to each other. The first metal cords are crossed with respect to the second metal cords. The third belt strip is in a radially external position with respect to the first and second belt strips. The at least one breaker layer includes reinforcing cords that are inclined with respect to the equatorial plane and is in a radially external position with respect to the belt structure. At least one reinforcing cord of the at least one breaker layer includes at least one metal wire deformed by a substantially sinusoidal deformation lying in a plane.

Tire for a vehicle wheel including at least one breaker layer

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.

Tire comprising metal cord

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.

Metal cord and process for manufacturing a metal cord

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.

Method and device for manufacturing a metal cord for reinforcing elastomeric products, particularly tires

A cord comprising at least a first pair and a second pair of wires (,) of different diameter randomly disposed in transverse cross section thereof, is obtained by arranging in a nacelle (,) of a double-twisting laying machine, a twister (,) operating upstream of a preformer (,). The twister (,), rotating in a direction opposite to that of the impeller (,) and at a speed which is twice that of the impeller, neutralizes the internal torsional stresses induced in the wires (,) 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 (,) disposed parallel in respectively coplanar axes is enabled. The obtained cord (,), within each laying pitch and only under a traction condition involving a load not exceeding 5 kg, has at least one right cross section in which at least one wire (,) is spaced apart from at least one of the adjacent wires so as to facilitate the rubberizing step, by enabling access of the blend to the cross section and penetration thereof along the cord axis. The cord is preferably used as a reinforcing element for the belt structure.

Process and apparatus for the manufacture of reinforcing metallic cord for elastomer-matrix composite articles

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. The obtained cord (1), within each laying pitch and only under a traction condition involving a load not exceeding 5 kg, has at least one right cross section in which at least one wire (2a, 2b) is spaced apart from at least one of the adjacent wires so as to facilitate the rubberizing step, by enabling access of the blend to the cross section and penetration thereof along the cord axis. The cord is preferably used as a reinforcing element for the belt structure.

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San Giovanni Valdarno, Italy

Omero Noferi