Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

Jacques Besson

Hichem Rehab

Nathalie Salgues

François Barbarin

Alain Domingo

Robert Ciprian Radulescu

Aurore Lardjane

Eric Berger

Sébastien Noel

Vincent Martin

Gilles Sallaz

Charlotte Caffeau

François Dimier

Mukul Gupta

Denis Bijaoui

David Lavialle

Philippe Tramond

Tire comprising a crown reinforcement formed of at least two working crown layers each formed of reinforcing elements inserted between two skim layers of rubber compound. First layer S of polymer compound is in contact with a working crown layer and the carcass reinforcement. The crown reinforcement comprises a layer of circumferential reinforcing elements. The elastic modulus under tension at 10% elongation of a skim layer of a working crown layer is less than 8.5 MPa, the maximum value of tan(&#x3b4;) of the skim layer of a working crown layer is &#x3c;0.100. First layer S comprises a filled elastomer blend having a macro dispersion coefficient Z&#x2265;65 and a maximum tan(&#x3b4;) value &#x3c;0.100 and its complex dynamic shear modulus G*, measured at 10% and 60&#xb0; C. on the return cycle is &#x3e;1.35 MPa.

Tire comprising a layer of circumferential reinforcing elements

Tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements. First layer C of rubber compound is placed between ends of the two working crown layers. Second layer S of polymer compound is in contact with at least one working crown layer and with the carcass reinforcement. The crown reinforcement includes at least one layer of circumferential reinforcing elements. The elastic modulus under tension at 10% elongation of first layer C is less than 8 MPa, the maximum value of tan(&#x3b4;) of first layer C is less than 0.100. The second layer S is made up of a filled elastomer blend having a macro dispersion coefficient Z greater than or equal to 65 and a maximum tan(&#x3b4;) value less than 0.100, and its complex dynamic shear modulus G*, measured at 10% and 60&#xb0; C. on the return cycle, is greater than 1.35 MPa.

Tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements, crossed from one layer to the other making with the circumferential direction angles comprised between 10&#xb0; and 45&#xb0;. A first layer S of polymer compound is in contact with at least one working crown layer and in contact with the carcass reinforcement, the first layer S of polymer compound extending axially as far as at least the axial end of the tread, the first layer S of compound polymer compound is made up of a filled elastomer blend having a macro dispersion coefficient Z greater than or equal to 65 and a maximum tan(&#x3b4;) value, denoted tan(&#x3b4;)max, less than 0.100 and its complex dynamic shear modulus G*, measured at 10% and 60&#xb0; C. on the return cycle is greater than 1.35 MPa.

Tire having improved dynamic properties

A tire comprising a crown reinforcement formed from at least two working crown layers of reinforcing elements and at least one layer of circumferential reinforcing elements, wherein, the tensile modulus of elasticity at 10% elongation of at least one skim coat of at least one working crown layer is greater than 9 MPa and the maximum value of tan(&#x3b4;), denoted tan(&#x3b4;)max, of said skim coat is less than 0.100.

Tire comprising a crown reinforcement comprising two working crown layers having unequal axial widths. Layer C of rubber compound is placed between ends of the working crown layers. Second layer S of polymer compound is in contact with at least one working crown layer and the carcass reinforcement, which comprises a layer of circumferential reinforcing elements arranged radially between two working crown layers. Distance d between the end of the axially narrowest working layer and the working layer separated from it by layer C is 1.1&#xf8;&#x3c;d&#x3c;2.2&#xf8;, &#xf8; being the diameter of the reinforcing elements, in a meridian plane. Second layer S is made up of a filled elastomer blend having a macro dispersion coefficient Z&#x2265;65 and a maximum tan(&#x3b4;) value less than 0.100. Its complex dynamic shear modulus G*, measured at 10% and 60&#xb0; C. on the return cycle is greater than 1.35 MPa.

Tire comprising a layer of circumferential reinforcement elements

The invention relates to a tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements the ends of which are radially uncoupled by a polymer compound. According to the invention, the reinforcing elements of at least one working crown layer are metal cords with saturated layers, at least one internal layer being sheathed with a layer consisting of a polymer composition such as a rubber composition and in each of the shoulders of the tire, at least the uncoupling polymer compound in contact with the ends of at least two working crown layers exhibits, in the sorption test, a gas content lower than 0.06 m/m.

Tire comprising a crown reinforcement

A tire having a crown reinforcement formed of at least two working crown layers having unequal axial widths, a layer C of rubber mixture being positioned between at least the ends of the said at least two working crown layers, and the crown reinforcement having at least one layer of circumferential reinforcing elements positioned radially between two working crown layers. The distance d between the end of the axially narrowest working layer and the working layer separated from the axially narrowest working layer by the layer C of rubber mixture is such that 1.1&#xf8;&#x3c;d&#x3c;2.2&#xf8;, &#xf8; being the diameter of the reinforcing elements of the said at least one layer of circumferential reinforcing elements, and, in a meridian plane, the thickness of the layer C of rubber mixture is substantially uniform.

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Clermont-Ferrand, France

Jacques Besson