A tread pattern of a pneumatic tire includes an inner circumferential main groove and an outer circumferential main groove that have groove walls extending in a tire circumferential direction while the angle of the groove walls relative to a contact surface varies with a predetermined amplitude, an inner lug groove extending from the inner circumferential main groove toward the outer circumferential main groove, an outer lug groove extending from the outer circumferential main groove toward the inner circumferential main groove, and a sipe configured to communicate the inner lug groove with the outer lug groove. A pair of chamfered surfaces are provided on walls of the sipe along an extension direction of the sipe on the contact surface.

A tire tread for a heavy-duty vehicle of construction plant type and aims to reduce the risk of cracking at the sipe bottom, without significantly reducing the volume of material of the tread so as not to shorten the lifetime of the tire in respect of wear. The tread (I) has transverse sipes (5) having a depth H and a width E, each transverse sipe (5) having a radially inner end formed by a bulge (53) having an end radius R, the transverse sipes (5) being distributed longitudinally at a longitudinal spacing B, the depth H, the width E of each transverse sipe (5), the end radius R of the bulge (53) and the longitudinal spacing B satisfying the relationship (R*B)/(E*H)>=1.8.

A pneumatic tire includes a tread having a pair of crown grooves, a pair of shoulder grooves, a crown land, a pair of middle lands, and a pair of shoulder lands. No grooves having width of 2 mm or more are formed in the crown and middle lands, the tread has first and second halves and has first sipes in the first half such that each has width of less than 2 mm and extends from the crown to shoulder lands via the grooves, second sipes in the second half such that each has width of less than 2 mm and extends from the crown to shoulder lands via the grooves without reaching the ground contact edge, and third sipes in the middle land in the second half such that each has width of less than 2 mm and extends in axial direction between second sipes adjacent in circumferential direction.

Tire tread (1) is divided into central part (20) and edge parts (30), central part (20) having width Lc between 40% and 90% of total width W of the tread. Edge parts (30) do not have any transverse cuts. Central part (20) has a tread pattern with circumferentially oriented sipe (21) and transversely oriented sipes (22, 22′, 22″) distributed around the periphery of the tread, such sipes having a depth at least equal to 60% of thickness E of material to be worn away and being interconnected to form a network. Such sipes are continued by hidden channels (210, 220). Central part (20) is delimited axially by transverse sipes (22′, 22″), each of which ends in end channel (221′, 221″) that opens onto tread surface (10) and extends into the thickness of the tread, and each end channel (221′, 221″) is connected to the network formed by the hidden channels.

A tread pattern of a pneumatic tire includes continuous lands provided in half treads on first and second sides, circumferential main grooves, and sipes having a chamfered configuration. The sipes extend inward in a lateral direction from the circumferential main grooves and are closed in the middle of regions of the continuous lands. An edge shape of each of sipes on the first side includes an extending portion extending inward in the lateral direction constantly in an extension direction and a bent portion that is provided to be joined to an end of the first extending portion and that has the edge shape bent from the extension direction of the first extending portion to a direction close to the circumferential direction. Every portion of the first extending portion and the bent portion of the sipes are provided with a main body portion and a sipe chamfered portion.

The tread has four grooves that delimit a central, intermediate and edge regions. Each intermediate region is divided into elongated raised elements that delimit oblique grooves which open into the circumferential grooves and are inclined at an average angle of between 30 and 60 degrees relative to the circumferential direction. The raised elements have an average circumferential length of between 50 and 70 mm. The depth of the oblique grooves is at least 30% of the depth of the circumferential grooves. Each raised element has a plurality of sipes that open into the oblique grooves. Each raised element also has an internal and oblique cut that has a total depth at least equal to 75% of the thickness PMU to be worn away. The oblique cut has a wide part and a part that forms a sipe that extends by a channel that forms a new groove after wear.

A tire comprises a tread portion including a first land portion provided with axially extending first lateral sipes. The first lateral sipe has a first sipe wall and a second sipe wall, and opens at a ground contacting top surface via a chamfer portion. The chamfer portion comprises a first sloped surface and a second sloped surface respectively connected to the first sipe wall and the second sipe wall. In a top view of the first land portion, the width W1 of the first sloped surface is larger than the width W2 of the second sloped surface.

A pneumatic tire that lowers a temperature of a tread portion by promoting heat dissipation thereof is provided. On a tread surface, a narrow groove is formed extending in a direction inclined with respect to a tire circumferential direction and having a width smaller than a depth, and an inflow portion opening to the tread surface is also formed on at least one of walls of the narrow groove facing each other in the tire circumferential direction.

A shear-controlled tire tread includes a plurality of narrow channels disposed generally perpendicular to a rolling direction. Each narrow channel includes a heel side, a toe side, and a valley connecting the heel side and the toe side, and a first plurality of ridges disposed on a heel side and a second plurality of ridges disposed on a toe side. The first plurality of ridges disposed on a heel side and the second plurality of ridges disposed on a toe side are offset and form interacting friction surfaces when a heel side of collapses toward a toe side or a toe side collapses toward a heel side.

Tread for a pneumatic tyre comprising a sipe having a sipe extension (L) and a sipe depth (P) along a direction of wear (U), wherein said sipe has at least two sections (S1, S2) along said direction of wear (U) having respective differentiated conformations, such that an intersection profile (P1, P2) between the sipe and a surface (T1, T2) parallel to the contact surface of the tread is different for each of said at least two sections (S1, S2), wherein at least one surface section (S1) of said at least two sections (S1, S2) has a depth (PS) that is variable along said sipe extension (L), said two sections (S1, S2) being connected by a transition section (S3) defining a transition line (TL) between the respective sections (S1, S2), said variable depth (PS) of said surface section, presenting a maximum depth (PSMAX) and a minimum depth (PSMIN), and wherein the surface section (SI) has a twisted configuration.