Pirelli Tyre S.p.a.

Pirelli Pneumatici S.p.a.

Piero Losi

Fiorenzo Brivio

Matteo Braga

Gaetano Lo Presti

Maurizio Boiocchi

Alfredo Balini

Rodolfo Noto

Claudio Lacagnina

Pierluigi De Cancellis

Franco Tonezzer

Method for controlling the symmetry of the footprint area of a tyre miming on a straight trajectory with camber angle different from zero, wherein the method comprises the steps: —reducing the contact pressure of the tyre () on the footprint area at an inner shoulder (in case of negative camber) or at an outer shoulder (in case of positive camber); —disposing any medium line (Im) of the tread band () placed in correspondence with the footprint area substantially parallel to the ground; the invention also defines a tyre and a wheel for motor-vehicles, wherein the medium line (Im) of the tread hand () and the rotation axis (X-X) of the tyre () form an angle (a) substantially equal in absolute value to the camber angle (β); the invention also encompasses a process for manufacturing such tyres, wherein a green tyre with symmetric outer profile is deformed during the vulcanising and moulding step until a predetermined angle (a) different from zero is formed between any medium line (Im) of the tread band () and the rotation axis (X-X) of the vulcanised tyre ().

Method for controlling the footprint area of a tyre and tyre for vehicle wheels

Method for controlling the symmetry of the footprint area of a tyre miming on a straight trajectory with camber angle different from zero, wherein the method comprises the steps: &#x2014;reducing the contact pressure of the tyre () on the footprint area at an inner shoulder (in case of negative camber) or at an outer shoulder (in case of positive camber); &#x2014;disposing any medium line (Im) of the tread band () placed in correspondence with the footprint area substantially parallel to the ground; the invention also defines a tyre and a wheel for motor-vehicles, wherein the medium line (Im) of the tread hand () and the rotation axis (X-X) of the tyre () form an angle (a) substantially equal in absolute value to the camber angle (&#x3b2;); the invention also encompasses a process for manufacturing such tyres, wherein a green tyre with symmetric outer profile is deformed during the vulcanising and moulding step until a predetermined angle (a) different from zero is formed between any medium line (Im) of the tread band () and the rotation axis (X-X) of the vulcanised tyre ().

Tire

A green tyre has a symmetric profile in radial section having a radially outer tread band, two radially inner beads and two sidewalls each extended from one edge of the tread band to one of the beads. During a moulding and vulcanisation treatment of the green tyre, a movement is imposed to the tread band with respect to the beads along a direction parallel to a rotation axis of the tyre, to obtain a moulded and vulcanised tyre having an asymmetric profile in radial section. A mould for vulcanizing tyres for vehicle wheels is also described, having a tread wall axially asymmetric with respect to a middle line plane of the mould.

Vulcanising mould for manufacturing tyres for vehicle wheels

A method for controlling the symmetry of the footprint area of a tire running on a straight trajectory with camber angle different from zero, includes the steps: reducing the contact pressure of the tire on the footprint area at an inner shoulder (in case of negative camber) or at an outer shoulder (in case of positive camber); and disposing any medium line of the tread band placed in correspondence with the footprint area substantially parallel to the ground. A tire and a wheel for motor-vehicles, wherein the medium line of the tread band and the rotation axis of the tire form an angle substantially equal in absolute value to the camber angle. A process for manufacturing such tires, wherein a green tire with symmetric outer profile is deformed during the vulcanizing and moulding step until a predetermined angle different from zero is formed between any medium line of the tread band and the rotation axis of the vulcanized tire.

A green tire has a symmetric profile in radial section having a radially outer tread band, two radially inner beads and two sidewalls each extended from one edge of the tread band to one of the beads. During a molding and vulcanization treatment of the green tire, a movement is imposed to the tread band with respect to the beads along a direction parallel to a rotation axis of the tire, to obtain a molded and vulcanized tire having an asymmetric profile in radial section. A mold for vulcanizing tires for vehicle wheels is also described, having a tread wall axially asymmetric with respect to a middle line plane of the mold.

Process and vulcanising mould for manufacturing tyres for vehicle wheels

A wheel for vehicles includes: a rim and a tire mounted on the rim and inflated to an operating pressure; axial end portions of a tread band of the tire radially spaced apart the same distance from a rotation axis of the wheel and a median circumferential line of the tread band axially shifted by a predetermined distance relative to a mid-line plane of the wheel; the wheel mounted on a car with a camber angle substantially zero and with the median circumferential line shifted toward the outside of the car relative to the mid-line plane.

Tyre for vehicle wheels

A high performance rain tire includes a tread band, having an inner portion and an outer portion as well as a central zone. There are formed in the tread band: two circumferential grooves in the inner portion, a central circumferential groove and a plurality of inner transverse grooves and a plurality of outer transverse grooves, wherein the inner transverse grooves include a central inner section which defines an angle with respect to the equatorial plane of between approximately &#x2212;95&#xb0; and approximately &#x2212;135&#xb0; and the outer transverse grooves include a central outer section which defines an angle, relative to the equatorial plane, of between approximately +125&#xb0; and approximately +165&#xb0;.

High performance rain tyre

A pneumatic tire has a carcass structure having at least one carcass ply and at least one annual reinforcing structure associated with the carcass ply, a tread band made of an elastomeric material at a radially outer position with respect to the carcass structure, a belt structure interposed between the carcass structure and the tread band and a pair of axially opposite side walls on the carcass structure, wherein the tread band has i) at least one first sector, radially extending, substantially of a first elastomeric material; ii) a plurality of second sectors radially extending, positioned at axially opposite sides of the at least one first sector and substantially of a second elastomeric material; iii) at least one longitudinal groove formed in the at least one first sector and extending substantially for the entire circumferential development of the tread band, wherein the first elastomeric material has a modulus of elasticity under compression at 23&#xb0; C. greater than the modulus of elasticity under compression at 23&#xb0; C. of the second elastomeric material, and wherein the modulus of elasticity under compression at 23&#xb0; C. of the first elastomeric material is about 20 to about 80 MPa.

Pneumatic tire and process for its manufacture

A tire for a vehicle wheel includes a carcass, a tread band radially external to the carcass, and a pair of axially distanced sidewalls. The carcass includes at least one carcass ply including ends associated with bead cores. Each bead core is incorporated in a respective bead and each bead includes a bead filler. Each sidewall is disposed, in a radial direction, between the tread band and a respective bead and is disposed in an axially outermost position. Each bead core includes a plurality of windings of a single wire. The plurality of windings is axially arranged side-by-side in a plurality of radially superposed layers, defines a transverse hexagonal section symmetrical with respect to an axis substantially parallel to the radial direction, and includes radially innermost and radially outermost layers. An axial width of the radially innermost layer is greater than an axial width of the radially outermost layer.

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Milan, Italy

Piero Losi