A circumferential narrow main groove extending in a circumferential direction in a tread of a pneumatic tire. The circumferential narrow main groove includes a narrow portion opening to a road contact surface of the tread and a widened portion having a wider groove width than the narrow portion. The widened portion is at a groove bottom. A groove width ratio (W2/W1) of a maximum groove width W2 of the widened portion to a groove width W1 of the narrow groove portion is in a range 1.5?(W2/W1)?4.0, and a cross-sectional area ratio (A2/A1) of a groove bottom-side cross-sectional area A2 to a groove opening-side cross-sectional area A1 in a meridian cross-section is within a range 1.2?(A2/A1)?4.0 when the circumferential narrow main groove is divided into two parts at 50% of a maximum groove depth of the circumferential narrow main groove. The cross-sectional area ratio changes along the circumferential direction.

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.

The tread comprises circumferential grooves which delimit an intermediate row (I) and edge rows (B). The tread also has a plurality of V-shaped oblique grooves with branches that make an angle of 30 to 60 with the axial direction. The circumferential and oblique grooves delimit a plurality of V-shaped blocks in each intermediate row. In each V-shaped block, there is a canal below the tread surface, and this canal has a width of 2 to 6 mm and is intended to generate a new groove after a predetermined amount of wear. When new, each canal has openings that open into the oblique grooves. A bridge of material is formed between the V-shaped blocks and occupies heightwise at least 40% of the depth of the oblique grooves and doing so over a width at least 10 mm. The bridge of material is suitable for not closing the openings of the canals.

A pneumatic tire for a vehicle with a tread having at least one profile rib, which is delimited on at least one side thereof by a circumferential groove. The circumferential groove has, when viewed in cross section, a portion running in the radial direction and having a width of up to 3.0 mm and, adjoining it, a radially inner channel region. The radially inner channel region is delimited by two channel walls and a channel base forming the groove base, and has a larger cross-sectional area and is made wider in each case than the portion running in the radial direction. The profile rib is provided over its circumference with sipes, which merge into the circumferential groove, run at an angle of 0? to 50? with respect to the axial direction and have a width of 0.4 mm to 1.2 mm and a maximum depth of 70% to 100% of the profile depth, and have sipe walls. Each sipe is locally widened by at least one channel which is open to the tread periphery and merges into the radially inner channel region of the circumferential groove. The channel is formed by a depression formed in one sipe wall and a depression formed on the other sipe wall, opposite the first depression.

A tire according to the present disclosure is a tire including, in a tread surface, a tread land portion partitioned by a partitioning groove or by the partitioning groove and a tread edge. The tread land portion includes a sipe extending from a surface of the tread land portion inwardly in a tire radial direction. The sipe includes a widened portion with a larger sipe width than a position adjacent in a sipe longitudinal direction. The cross-sectional area of the widened portion in cross section perpendicular to the tire radial direction is larger on inside than on outside in the tire radial direction.

Tire tread (1) made of elastomeric material, having a tread surface intended to come into contact with a road surface when the tire rolls. The tread includes a plurality of cuts opening onto the tread surface, each cut having a sipe (3) delimited by facing first walls (4), and a widening zone (5) delimited by second walls (6) widening the sipe in the depth of the tread, the roughness of the first walls (4) being different from the roughness of the second walls (6) of material.

A tire includes a central region configured to be mounted to a wheel and a crown region including a circumferential tread. A plurality of voids are disposed in the crown region, below a surface of the circumferential tread. The tire further includes an intermediate region extending from the central region to the crown region.

Disclosed herein is a kerf of a winter tire capable of easily discharging snow therefrom and further improving braking performance and drainage performance on a wet road. The kerf includes a kerf inlet portion formed in the shape of a sawtooth-type zigzag wave in a block of one of a tread and a shoulder of the tire in the circumferential direction of the tire, a pipe-shaped flow passage portion formed in a lower portion of the block and having a width that is greater than or equal to the width of the kerf inlet portion, and a connection channel for connecting the kerf inlet portion and the flow passage portion to each other. The sawtooth-type zigzag wave has an amplitude that gradually decreases in the depth direction of the block, and the connection channel has a width that gradually decreases from the kerf inlet portion to the flow passage portion.

A tire includes a tire frame member that is formed from a resin material and has a bead portion, side portions, and a crown portion, a belt layer serving as an example of a reinforcing layer that is disposed at the outer side in a tire radial direction of the tire frame member, and has a higher bending rigidity than outer circumferential portions of the tire frame member, a top tread serving as an example of a tread that is formed from a rubber material and is disposed at the outer side in the tire radial direction of the belt layer, and first width direction grooves serving as an example of width direction grooves that are provided at the top tread. An aperture surface area of one of the first width direction grooves within a total ground contact surface of the tread of one circumferential direction portion of the tire is 0.02% or less relative to a surface area of a total ground contact surface of the tread of one circumferential portion of the tire.

The present invention includes an improved tire tread having recessed lateral grooves, and a tire having the same. Particular embodiments of the tread include a tread thickness bounded depthwise by a top side configured to engage a ground surface during tire operation and a bottom side configured to attach to a tire carcass, the thickness extending laterally between a first side edge and a second side edge and longitudinally in a lengthwise direction of the tread. The tread further includes a longitudinal groove in fluid communication with the top side or the bottom side of the tread thickness and a lateral groove in fluid communication with the bottom side of the tread thickness extending from the first side edge intersecting the longitudinal groove forming a vent passageway extending from the longitudinal groove and to the first side edge. The invention includes methods of forming such treads and molds there for.