Abstract: A tread of elastomeric material for tires, this tread being provided with a plurality of incisions, each incision of average width e being defined by facing walls, this tread being characterized in that at least one of the walls defining each incision comprises at least one first series and one second series of lines of motifs forming reliefs relative to said wall and having a maximum height measured perpendicular to said wall at least equal to 1/10 of the width e, each series of lines comprising a plurality of lines extending in the same direction, the lines of the first series intersecting the lines of the second series, and in that at least one of the walls is provided over its entire surface with an average roughness of between 1/100 and 1/10 of the width e of the incision.

Abstract: A tread of elastomeric material for tires, this tread being provided with a plurality of incisions, each incision of average width e being defined by facing walls, this tread being characterized in that at least one of the walls defining each incision comprises at least one first series and one second series of lines of motifs forming reliefs relative to said wall and having a maximum height measured perpendicular to said wall at least equal to {fraction (1/10)} of the width e, each series of lines comprising a plurality of lines extending in the same direction, the lines of the first series intersecting the lines of the second series, and in that at least one of the walls is provided over its entire surface with an average roughness of between {fraction (1/100)} and {fraction (1/10)} of the width e of the incision.

Abstract: A mold for molding a tread, in particular of a tire, having first elements in relief and second elements in relief for cooperating in the molding configuration to form a molding element intended to mold a single cutout opening both on to the running surface of the tread and on to one of the lateral edges of said tread and to define at least one orifice intended to allow the rubber mix to pass during the molding of the tread.

Abstract: A tread for a tire having, on at least one lateral part, and radially to the inside of the running surface of said tread, a plurality of cavities oriented virtually transversely and opening onto at least one of the edges of the tread, the cavities being intended to form grooves and incisions opening radially towards the outside of the tread after wear of between 15% and 45% of the thickness of the tread when new. Also, a mold adapted for the molding of such a tread pattern and including, on at least one part molding one of the sidewalls, elements in relief for molding cavities radially beneath the running surface of a tread when new.

Abstract: A molding element intended to equip a mold for molding, in a tread made of a rubber compound, a non-demoldable pattern, the element including at least one part molding a part of a pattern with an undercut. The molding element is one wherein during at least part of the demolding operation, the projected area of each part molding a pattern with an undercut onto a plane perpendicular to the demolding direction is smaller than the area of the same part projected onto the same plane in the molding position, so as to make demolding of the molding element easier.

Abstract: A tire tread (10) comprising at least some elements in relief, provided w at least one incision (1), each of the facing walls P of which has a surface in relief, formed of protrusions (2) and of cavities (3) arranged on opposite sides of a central wall surface M, each of such protrusions (2) and cavities (3) having, on said central surface (M), a quadrilateral base (b.sub.S, b.sub.C) and a vertex (S, O', A', B', C') spaced from said surface, the base b.sub.S of a protrusion (2) being completely surrounded by bases b.sub.C of cavities (3).

Abstract: In order to optimize the behavior of a conventional passenger car on snow-covered and icy ground, the driving axle of said vehicle is equipped with tires the treads (1) of which are provided with elements in relief (11) having incisions (14) of a width other than zero, the traces of which are transverse while the load-bearing axle of the same vehicle is equipped with tires of the same structure but with treads (2, 3) provided with elements in relief or blocks (21, 31) having incisions (24, 34) of a width other than zero, the traces of which are elliptical.

Abstract: In order to improve the compromise between the properties of adherence to ow-covered or icy ground and its wear properties, the tread of a tire which is provided with incisions having a width other than zero and, seen in cross section, fork-shaped traces with two branches, has grooves the walls of which are provided with an incision which forms with the trace of the groove a trace which is symmetrical to the trace of the incision which is parallel to and closest to said groove.

Abstract: Certain elements in relief (11, 13) of a tread (1) for a radial tire are vided at least with incisions (41, 42, 43) which in cross-section have a fork-shaped outline with at least two branches (41B, 41C) forming an extension of a single part (41A), the number of incisions (41) in the element in relief (11, 13) being multiplied by a factor equal to at least 1.5 starting from the depth (h.sub.1) of the double-branched incision (41). Use of such treads for tires intended to travel on wet, snow-covered or icy ground.

Abstract: In order to improve the wear life of a tread having elements in relief which are provided with numerous incisions, each element in relief which is defined by circumferential grooves and transverse grooves comprises an even number of incisions which have rectilinear traces on the surface of the tread and, in cross-section, broken line or undulated line traces, the mean axes of which are perpendicular to the surface of the tread, and in such manner that the trace of one incision is identical to the symmetrical trace, with respect to its mean axis, of the trace of a circumferentially adjacent incision.