Michelin Recherche Et Technique S.a.

Compagnie Generale Des Etablissements Michelin

Societe Detechnologie Michelin

Compagnie Generale Des Establissements Michelin

Bertrand Fraenkel

Arnaud Frappart

Sébastien Fugier

Illyes Batnini

Marie-Helene Vantal

Nicolas Jamot

Vincent Ledieu

Michel Montarras

Marie-Hélène Vantal

A snow tire tread having a plurality of blocks separated by grooves and provided with sipe incisions dividing into several parts from a certain depth onwards, (complex sipes each having, when viewed in cross section, a rectilinear first part extending radially from the tread surface of the tread, and a second part extending the first part and comprising at least two branches each having an end. The tread has cavities each extending between the branches of a complex sipe and having a bottom situated at the same level as the ends of the branches. The cavities and the grooves of the tread are configured so that this tread has a voids surface ratio at the end of wear greater than or equal to 35%. Furthermore, the distance (D) between two branches of two adjacent complex sipes is at least equal to 2 mm.

Snow tire tread comprising incisions and cavities

The invention relates to an asymmetric tread for a tire comprising a plurality of basic patterns, for each of which there is defined a sipes density corresponding to where i is the number of sipes in the pattern, li is the length of the isipe on the tread surface, P is the pitch of the basic pattern and Wm is the width of the basic pattern, a sipes orientation level corresponding to where &#x3b1;i is the positive or negative angle formed on the tread surface by the isipe with the transverse direction and |&#x3b1;i|&#x2264;45 degrees and a steering pull criterion for the basic pattern corresponding to The sipes density is greater than or equal to 60 &#x3bc;m/mm, the sipes orientation level is greater than or equal to 1.5 degrees/mm and the steering pull criterion for the pattern is less than or equal to 0.2. The tread comprises an inboard half-tread adjacent to an inboard sidewall of the tire, the sipes orientation level relating to the inboard half-tread being greater than 2 degrees/mm.

Tire tread

A tread having a plurality of grooves formed on each half of the tread on each side of a midplane X-X', each opening axially to the outside and extending axially towards the midplane X-X&#x2032; so that the plurality of grooves forms a first pattern in the overall shape of a V pointing in a groove direction Xr. The tread includes a plurality of sipes. From a certain degree of wear onwards, all or some of the sipes become enlarged forming cavities extending in an oblique direction forming a second pattern in the overall shape of a V pointing in a cavity direction Xc. Each of these cavities opens into just one of the grooves of the tread, the plurality of grooves forming, at this level of wear, the same first pattern.

Tire tread with directional design

Pneumatic tire

Growing community of inventors

Saint-Pierre-Roche, France

Bertrand Fraenkel