Michelin Recherche Et Technique S.a.

Compagnie Generale Des Etablissements Michelin

Societe Detechnologie Michelin

Organisation Mecanographique Et Comptable Gervais Omc Gervais

Philippe Gervais

Benjamin Quantinet

Gilles Godeau

Pierre Durif

Lucien Bondu

Hichem Rehab

Christophe Gayton

Tony Zivkovic

Guillaume Bacher

Gilles Sallaz

Alain Durand

Stèphane Callamand

Stephane Vartanian

A tire tread having a tread surface () in the new state and at least one wavy groove () opening into the tread surface, the groove is the new state having external cavities () that open onto the tread surface in the new state along a length (Le) and internal cavities () that do not open onto the tread surface. The external cavities () have a bottom () of which the points that are innermost in the tread are at a distance (H) from the tread surface () in the new state, the internal cavities () having a bottom () of which the innermost points are at a distance (H) from the same tread surface (). The external cavities () and the internal cavities () being connected together by linking cavities (). The tread () being such that at least two sipes () are formed from the bottom () of the external cavities () and along an entire length (Le) of these external cavities ().

Tire of which the tread comprises wavy grooves

A tire with radial carcass reinforcement, comprising a crown reinforcement, itself capped radially by a tread connected to two beads by two sidewalls, the said tread comprising at least two radially superposed layers of polymer compound, a first layer of filled elastomeric compound, constituting the radially outer part of the tread, has a macrodispersion score Z higher than 80 and a maximum tan(&#x3b4;) value, denoted tan(&#x3b4;)max, lower than 0.130 and a second layer of elastomeric compound radially on the inside of the said first layer of elastomeric compound has an elongation at break at 60&#xb0; C. that is higher than 600%.

Tire comprising a tread made up of several elastomeric compounds

A tire the tread of which contains at least three circumferential grooves, having at least three radially superposed layers of elastomeric compounds. A first elastomeric compound constituting the first layer forming the radially outer part of the tread has a maximum value of tan(&#x3b4;)max, greater than 0.110, a second elastomeric compound constituting the second layer radially on the inside has a tan(&#x3b4;)max at least 10% lower than the first elastomeric compound, the radially innermost third layer of the tread consists of at least two first parts and of at least three second parts axially, each one in contact with at least one of the at least two first parts, the at least two first parts axially centered on a radial plane passing through one of the at least three circumferential grooves consisting of the second compound and the at least three second parts consisting of a third elastomeric compound having a maximum value of tan(&#x3b4;), denoted tan(&#x3b4;)max, at least 10% lower than the second elastomeric compound.

Pneumatic tire

A tire includes a radial carcass reinforcement surmounted radially by a crown reinforcement including a working reinforcement having two working crown plies of calendered inextensible metallic reinforcement elements and rubber mix. The reinforcement elements are parallel to each other within each ply and are crossed from one ply to the next, forming with the circumferential direction respective angles &#x3b1;and &#x3b1;of between 10&#xb0; and 45&#xb0;. The working crown plies have respective axial widths Land L. The tire also includes a protective ply of metallic reinforcement elements with an axial width Lsuch that L&#x3c;L, Lbeing the width of the working ply adjacent to the protective ply. A layer of cohesive rubber mix GB is arranged radially internal to the working reinforcement such that the axially outer end of the layer GB is at a distance from the equatorial plane greater than L/2.

Crown reinforcement for a radial tire

The invention relates to a tire in which at least one first profiled element P of rubber mix separates the axially widest ply of reinforcement elements from at least one end of a second ply, axially narrower than the axially widest ply, the axially outer end of said first profiled element P being located at a distance from the equatorial plane of the tire which is less than the distance between said plane and the end of the axially widest ply of reinforcement elements, said profiled element P being radially separated at least in part from the liner C of said axially narrower ply of reinforcement elements by a second profiled element of rubber mix G, and said first and second profiled elements of rubber mix P and G and said liner C having secant modules of elasticity under tension at 10% elongation MP, MG, MC respectively such that MC&#x2267;MG&#x3e;MP.

A tire for vehicles carrying heavy loads, comprising in at least one bead an additional reinforcement composed of a plurality of discontinuous reinforcing elements, these discontinuous reinforcing elements being orientated essentially circumferentially to form a plurality of circles C, C, Cconcentric on the rotation axis of the tire mounted on its rim, each circle being defined by a mean radius (R, R, R) measured relative to the said rotation axis.

Growing community of inventors

Clermont-Ferrand, France

Philippe Gervais