A heavy duty pneumatic tire in which occurrence of uneven wear is inhibited is provided. In the tire, each shoulder land portion includes a groove wall portion forming a wall of a shoulder circumferential groove, and a cap portion located outward of the groove wall portion in an axial direction. A wear resistance index of the groove wall portion is lower than a wear resistance index of the cap portion. A ratio of a distance in the axial direction from an outer edge of the shoulder circumferential groove to a boundary between the groove wall portion and the cap portion on an outer surface of the shoulder land portion, to a width in the axial direction of the shoulder land portion, is not less than 20% and not greater than 30%.

A tire includes a tread portion being provided with a circumferentially extending main groove to define a first land portion between the main groove and a tread edge. The main groove includes a groove bottom, an outer groove wall extending radially outwardly and inclined toward the tread edge, and an inner groove wall extending radially outwardly and inclined toward the tire equator. The groove bottom extends in a zigzag manner in a tire circumferential direction in such a manner as to alternate between a first location where the groove bottom is located nearest to the tire equator and a second location where the groove bottom is located nearest to the tread edge. An angle 2b of the outer groove wall in a groove cross-section at the second location is greater than an angle 1a of the inner groove wall in a groove cross-section at the first location.

The present invention relates to a tire tread comprising a tread cap comprising at least one tread cap rubber compound, at least three circumferential grooves, wherein at least portions of the sidewalls and the bottom of each of said grooves are formed by a circumferential groove reinforcement, and wherein a first groove reinforcement of a groove laterally next to the equatorial plane of the tire comprises a first reinforcement rubber compound which has a higher hardness than the tread cap rubber compound, and wherein a second groove reinforcement of a groove with a larger lateral distance to the equatorial plane of the tire than the first groove, comprises a second reinforcement rubber compound which has a higher hardness than the tread cap rubber compound and a lower hardness than the second reinforcement rubber compound.

A pneumatic tire includes a tread portion including a contact patch which occurs when the tire is mounted on a standard wheel rim with a standard pressure and loaded with a certain tire load at zero camber angle. The contact patch, on a respective tire load, defines a ratio Lc/Ls of a crown contact circumferential length Lc at an axial center of the contact patch to a shoulder contact circumferential length Ls at an axial location of 80% of an axial maximum width of the contact patch. The ratio Lc/Ls upon being loaded with 40%, of a standard tire load is equal to or less than 125% of the ratio Lc/Ls upon being loaded with 70% of the standard tire load.

A tire includes a pair of sidewalls and a circumferential tread having a zigzag circumferential groove. The zigzag circumferential groove is defined by a groove bottom, a pair of groove walls, and a pair of groove edges defining an intersection between each groove wall and a top surface of the circumferential tread, wherein each of the groove edges smoothly widens and narrows along the groove. The circumferential tread has a first circumferential pitch with first and second circumferential pitch lengths. The first circumferential pitch includes a first zigzag circumferential groove segment and a second zigzag circumferential groove segment that form a first intersection angle. The second circumferential pitch includes a third zigzag circumferential groove segment and a fourth zigzag circumferential groove segment that form a second intersection angle different from the first intersection angle.

A pneumatic tire has a tread having adjacent rib-shaped land portions (4) with circumferential grooves (3) therebetween. Annular elongate projection portions (5, 5) project toward each other from adjacent rib-shaped land portions (4). The elongate projection portions (5, 5) confronting each other are disposed with a spacing therebetween such that their mutually confronting tip surfaces (5s, 5s) make contact with each other due to elastic deformation of the rib-shaped land portions (4, 4) at the time of grounding of the tire. An inside groove space (6) is formed on a radially inner side of the confronting elongate projection portions (5, 5) and an outside groove space (7) is formed on a radially outer side of the elongate projection portions (5, 5). The tip surfaces (5s) of the elongate projection portions (5) are formed with a plurality of communication recesses (9) providing communication between the inside and outside groove spaces (6, 7). The communication recesses (9) are formed at intervals in a tread circumferential direction. It is thus possible to enhance rigidity of the rib-shaped land portions over the whole tread at the time of grounding of the tire, thereby to suppress elastic deformation of the rib-shaped land portions and to reduce rolling resistance, while securing a draining property attributable to the circumferential grooves.

The molding element has a molding surface for forming a contact face of the contacting elements and a groove forming rib portion for forming the groove. The groove forming rib portion has opposed rib side faces for forming opposed groove side faces and a rib top face connecting the rib side faces for forming a groove bottom. The groove forming rib portion provides at least one space opening to at least one of the rib side faces and/or to the rib top face and an insert is received in the space. The insert is composed of a plurality of thin plates stacked in a direction along which the rib extends and comprises at least one notched plate of thickness t1 including at least one notch for forming a flexible fence of the closing device; and comprises at least one support plate of thickness t2 without notch.

A pneumatic tire comprises a tread portion 2 provided with at least one circumferentially continuously extending main groove 3. The main groove 3 has a zigzag periodical pattern formed by circumferentially repeatedly arranging a first oblique segment 11 and a second oblique segment 12 as a repeating unit which define one zigzag pitch. The first oblique segment 11 extends without being bent, and the second oblique segment 12 extends in a bent manner.

Tire tread (1) comprising groove (2) of depth (P) that opens onto tread surface (10) of the tread in the new state, this groove comprising a plurality of first and second portions of groove, each first portion (21) of groove being delimited by facing walls (211, 212) spaced apart by a maximum width (L1) measured at the tread surface when new, these walls (211, 212) approaching one another such that, at a depth (H11) between 20 and 80% of the total depth (P) of the groove, they are spaced apart by a width (L1) less than the maximum width (L1). Walls (211, 212) diverge from one another down to the depth (P) of the groove such that they are spaced apart from one another by a width (L1). Each second portion (22) of groove is delimited by facing walls (221, 222) spaced apart by a minimum width (L2) measured at the tread surface (10) when new, these walls (221, 222) diverging from one another such that, at a depth (H21) between 20% and 80% of the total depth (P) of the groove, they are spaced apart from one another by a width (L2) greater than the width (L2). Walls (221, 222) then approach one another down to the depth (P) of the groove such that they are spaced apart by a width (L2). Groove (2) is formed by a plurality of first and second portions of groove so as to form a continuous passage (3) between all the portions of groove in order to allow liquid to flow in the groove regardless of the level of wear, this continuous passage (3) being broken down into two elementary passages (31, 32).

A tyre for vehicle wheels having a tread pattern includes: a) two circumferential grooves, which define a first and a second shoulder region, and one central region; b) a plurality of asymmetric transverse grooves having a substantially V shape, which extend for the whole width of the tread, including an alternate sequence of a first and a second asymmetric transverse groove defining an alternate sequence of a first and a second asymmetric module; and c) a plurality of lateral transverse grooves, which includes one first lateral transverse groove extending for the whole width of the first shoulder region and for a portion of the central region of the first asymmetric modules, and one second lateral transverse groove extending for the whole width of the second shoulder region and for a portion of the central region of the second asymmetric modules.