Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

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Compagnie Generale Des Etablissments Michelin

Michelin Recherche Et Tehcnique, S.a.

Christophe Gayton

Walid Djabour

Benjamin Quantinet

Stéphane Oraison

Matthieu Vandaele

Arnaud Larregain

Damien Bardin

Fabien Marlier

Maxime Rolland

Hichem Rehab

Damien Thomasson

Tony Zivkovic

Philippe Gervais

Guillaume Demaziere

Vincent Martin

Saliou Dieng

Tire with radial carcass reinforcement having a tread of thickness E, this tread having a tread surface and at least one cut opening onto the tread surface to form edge corners. The cut extends into the tread over a total depth H. The cut is in the form of a sipe having a width D. There is also formed, in the vicinity, i.e. at a minimum distance from the said edge corner that is at most equal to five times the width D of the cut, of at least one edge corner of this cut and on the tread surface, at least one cavity having a depth h that is small in comparison with the depth of the cut, i.e. that is at most equal to 30% of the depth H. The at least one cavity reduces the compression rigidity of the tread in the vicinity of the the at least one edge corner.

Tread protection device

The tire tread having a tread surface and a total thickness E and at least one main groove which opens when new onto a tread surface. In the vicinity of this main groove, at least one discontinuous secondary groove has a plurality of hidden parts and a plurality of open parts. The open parts are open onto the tread surface when new. The main groove and the discontinuous secondary groove have roughly identical main directions. The mean distance L, which is a distance measured at the open parts between the mean surface of the main groove and the mean surface of the discontinuous groove, is less than the mean distance Lmeasured between the mean surface of the main groove and the mean surface of the discontinuous groove in the regions of the discontinuous groove that do not have open parts.

Tire tread

The tread has a total width W and two main grooves. The main grooves divide the tread into a middle region and edge regions. The middle region has an axial width Lm that is 45% to 70% of the total width W. The volume void ratio of the tread when new is less than 17%. An internal surface extends parallel to the tread surface when new and is in contact radially with the innermost points of the deepest main grooves. The middle part has a plurality of transverse sipes, each of which has a depth at least equal to the depth of the main grooves. The transverse sipes open into the main grooves. The middle region has a volume void ratio when new that is less than half the total volume void ratio of the tread, and at least one circumferential channel appears when the tread becomes part worn.

Tread for heavy vehicle tire

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.

Tire comprising a tread made up of several elastomeric compounds

A tire with radial carcass reinforcement comprising a crown reinforcement itself capped radially with a tread of which the tread pattern comprises at least two circumferential grooves. The tread is made up of at least three layers, a first layer forming the radially outer part of the tread of a first compound having an electrical resistivity per unit volume &#x3c1;such that log(&#x3c1;) is less than 6, a second layer radially on the inside of at least three parts, at least the axially outer parts of a second compound having an electrical resistivity per unit volume &#x3c1;such that log(&#x3c1;) is greater than 10, and at least part, radially extending the at least first elastomeric compound of the first layer, of a third elastomeric compound having an electrical resistivity per unit volume &#x3c1;such that log(&#x3c1;) is less than 6, a third layer radially furthest towards the inside of at least five parts, at least the axially outer parts of a third elastomeric compound having a maximum value of tan(&#x3b4;), denoted tan(&#x3b4;)max, of less than 0.080, at least two parts of the second compound, and at least part of the third layer, that radially extends the at least one part of the second layer of the third elastomeric compound.

Tire with radial carcass reinforcement having a tread of thickness E, this tread having a tread surface to come into contact with a roadway and comprising at least one cut opening onto the tread surface to form edge corners, this cut extending into the tread over a total depth H at most equal to the thickness E of the tread, this cut being, between the tread surface and a depth Hat most equal to the total depth H, in the form of a sipe having a width D suitable for being able to close up at least in part under normal running conditions of the tire. There is also formed, in the vicinity, i.e. at a minimum distance from the said edge corner that is at most equal to five times the width D of the cut, of at least one edge corner of this cut and on the tread surface, at least one cavity having a depth h that is small in comparison with the depth of the cut, i.e. that is at most equal to 30% of the depth H, this at least one cavity reducing the compression rigidity of the tread in the vicinity of the said at least one edge corner.

Growing community of inventors

Clermont-Ferrand, France

Christophe Gayton