Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

Hervé Ferigo

Olivier Muhlhoff

Hélène Emorine

Mathieu Vandaele

Richard Cornille

Sabrina Rih

José Merino Lopez

Pascal Prost

Gael Roty

Jacky Pineau

Sophie Gander

Kazutaka Yokokawa

Yann Chaylard

Frédéric Vallence

A tire () comprises a crown () comprising a tread (), a crown reinforcement (), a carcass reinforcement (), two side walls (), two beads (), each side wall () linking each bead () to the crown (), the crown reinforcement () extending in the crown () in a circumferential direction (Z) of the tire (). The textile wire-like hoop reinforcer element (), the wire-like working reinforcer elements () and the wire-like carcass reinforcer elements () are arranged so as to define, in projection on the equatorial circumferential plane (E), a triangular mesh. The textile wire-like hoop reinforcer element comprises a core composed of a first strand comprising at least one monofilament, and a layer comprising at least two second strands, each second strand comprising at least one monofilament, each second strand of the layer being helically wound around the core.

Tire comprising specified hooping ply

The rolling resistance of a tire has been improved without degrading industrial performance. The sidewall () consists of two sub-layers. A first sub-layer (FE) of thickness E1 and volume V1 provides the expected protection functions of a sidewall as the outer wall of the tire, and a second sub-layer of the sidewall (FE) of thickness E2 and volume V2 is optimized at low hysteresis to improve rolling resistance. The ratio V1/(V1+V2) of the volumes of the two sub-layers (FE, FE) is less than or equal to 0.3. The elongation at break of the compound of FEis greater than or equal to 200% measured at a temperature of 100° C., and the viscoelastic loss of the compound of FE, Tan(δ)max, is less than or equal to 0.10.

Tire having optimized performance in terms of rolling resistance without impairing the industrial performance

The invention relates to a tyre () comprising a hooping ply () comprising at least one textile wire-like hoop reinforcer element making an angle strictly less than 10° with the circumferential direction (Z) of the tyre (). The bonded textile wire-like reinforcer element has, before the step of production of the hooping ply (), a tangent modulus less than or equal to 5 cN/tex/% for any elongation less than or equal to 3%. The textile wire-like hoop reinforcer element has, once extracted from the tyre (), a tangent modulus greater than or equal to 5 cN/tex/% for any elongation greater than or equal to 4%.

Pneumatic tire comprising specified hoop reinforcer element

A tire for a motor vehicle comprising: two beads (); two sidewalls () meeting at a crown (); at least one carcass reinforcement () extending from the beads () through the sidewalls () as far as the crown (), the carcass reinforcement () having a plurality of carcass reinforcing elements and anchored in the two beads () by a turn-up around the annular reinforcing structure (), so as to form in each bead a main strand () and a turn-up strand (); and a stiffening reinforcement () arranged in at least one sidewall of the tire, said stiffening reinforcement () having a radially inner end () and a radially outer end (), the stiffening reinforcement being formed of a plurality of stiffening elements oriented at an angle less than or equal to 10° relative to a circumferential direction of the tire.

Tire having a reinforced lower zone

Tire with sidewalls () having, on their outer surfaces, a set of protuberances () that alternate with voids (). The tread () comprises a circumferential groove () at at least one axially outermost end (). Each protuberance () is disposed at the surface of a sidewall, the different protuberances being disposed regularly or irregularly and continuously or discontinuously between a point A and a point E. The inner wall () of the carcass ply () of the tire is partially or entirely covered with at least one layer of a self-sealing composition ().

Extended-mobility cross-ply or radial tire

The invention relates to a tire having at least one carcass reinforcement () comprising reinforcers, surmounted radially on the outside by a crown reinforcement () comprising two axial ends S, itself radially on the inside of a tread (), said crown reinforcement () being made up of at least one layer of reinforcement elements, said tread () being connected to two beads () by way of two sidewalls (), said beads () being intended to come into contact with a rim flange having a rim flange top C, each bead having at least one circumferential reinforcement element () known as a bead wire, said carcass reinforcement () comprising an end () at each bead (), the end () of the carcass reinforcement () being turned up once in an outward radial direction of the tire and about said bead wire, so as to form a turnup, then being folded in the radially outward direction so as to form a fold of the carcass ply (), said fold forming a radially external end () and three adjacent parts along an axial axis made up of a central part (), of an axially internal lateral part (), and of an axially external lateral part (), the fold being executed in an outward axial direction with respect to the center of the tire, characterized in that a decoupling elastomer composition () having a secant modulus at 10% extension of greater than or equal to 10 MPa and preferably greater than or equal to 30 MPa and less than or equal to 60 MPa is present between the axially internal lateral part and the central part of said turnup, and at the radially external end () of said turnup (), said elastomer composition being present along a radial length comprised between the radially external end of the turnup and a radially internal point F with respect to the end of said turnup, said point being situated on the sidewall and at a distance from said radially external end by a length greater than 10 mm, and in that the radially external end () of the turnup () is disposed between the rim flange top C and a point D, said points C and D being situated at the surface of the sidewall () and disposed on either side of a point E situated on the sidewall corresponding to the nominal section width, said point D being disposed at a maximum radial length equal to 85% of the length present between the axial end S of the crown reinforcement () and the rim flange top C.

Reinforced cross-ply or radial tire

The invention relates to a tire having at least one carcass reinforcement comprising reinforcers, surmounted radially on the outside by a crown reinforcement, itself radially on the inside of a tread, said crown reinforcement being made up of at least one layer of reinforcement elements, said tread being connected to two beads by way of two sidewalls, said beads being intended to come into contact with a rim flange having a rim flange top C, each bead having at least one circumferential reinforcement element, said carcass reinforcement comprising an end at each bead, the end of the carcass reinforcement being turned up once in an outward radial direction of the tire and about said bead wire, so as to form a turnup, then being folded in said radially inward direction so as to form a fold forming a radially external end and three adjacent parts along an axial axis made up of a central part, of an axially internal lateral part, and of an axially external lateral part. The tire is characterized in that the radially external end of the turnup is disposed between the rim flange top C and a point D, said points C and D being situated at the surface of the sidewall and disposed on either side of a point E situated on the sidewall corresponding to the nominal section width, said point D being disposed at a maximum radial length equal to 85% of the length present between the axial end S of the crown reinforcement and the rim flange top C.

Reinforced bias- or radial-carcass tire

A tire comprising a carcass reinforcement () surmounted radially on the outside by a crown reinforcement (), itself radially on the inside of a tread () having two axially outermost ends. The crown reinforcement () has a layer of reinforcing elements. The tread is connected to two beads () by two sidewalls (), each bead () comprising at least one circumferential reinforcing element. Sidewalls () comprise, on their exterior surface, a series of protuberances () alternating with voids (). The tread () comprises, at least at one axially outermost end (), a circumferential groove (), wherein each protuberance () is positioned at the surface of a sidewall, the different protuberances being arranged regularly or irregularly and continuously between a point A and a point E, and wherein at least one protuberance () partially or completely interrupts or does not interrupt the circumferential groove ().

Growing community of inventors

Clermont-Ferrand, France

Hervé Ferigo