The present disclosure provides for a molding element for a mold used for manufacturing a tread of a tire having a plurality of contacting element, a plurality of grooves and a connecting member connecting two side faces of adjacent contacting elements, the molding element having a molding surface and a rib for forming the groove between adjacent contacting elements and at least two rib side faces, the rib having a notching portion, a guiding member made of a material different from a material of the molding element being received in the notching portion and has two opposite side faces and a top face configured to form a part of a bottom of the groove, a distal end of the rib projecting member has a chamfered surface facing to an obliquely upward direction for guiding the connecting member toward the guiding slit.

A heavy-duty pneumatic tire comprises a crown rib and a middle rib. The crown rib is provided with crown sipes crossing the crown rib. The middle rib is provided with middle sipes crossing the middle rib and a middle shallow groove having a smaller depth and a larger width than the middle sipes. The middle shallow groove comprises a circumferential middle shallow groove extending in a tire circumferential direction and lateral middle shallow grooves extending from an axially inner side edge (Ema) of the middle rib to the circumferential middle shallow groove so as to terminate at a position thereof.

A tread surface of a tread portion of a pneumatic tire comprises a circumferential main groove and a projection body extending continuously in a tire circumferential direction, the projection body projecting in a tire radial direction from a groove bottom of the circumferential main groove; and connecting portions connecting the projection body and groove walls of the circumferential main groove alternately disposed in the tire circumferential direction on first and second sides of the projection body in a tire lateral direction; a relationship of L to a total of V.sub.1 to V.sub.n and W.sub.1 to W.sub.n satisfying from 0.7 L to 1.5 L, where L is a circumferential length of the projection body, and V.sub.1 to V.sub.n and W.sub.1 to W.sub.n are circumferential dimensions of the connecting portions on the first and second sides of the projection body in the tire lateral direction, respectively.

The present invention provides a pneumatic tire including: a groove formed in a tread, the groove having a groove bottom and groove side surfaces arising from the groove bottom; and a projection projecting from the groove bottom, wherein the projection includes a low-step portion located at a low position with reference to the groove bottom and a high-step portion located at a high position with reference to the groove bottom, the low-step portion has a first-side inclined surface inclined in a depth direction of the groove along a first groove side surface of the groove and a second-side inclined surface inclined in the depth direction of the groove along a second groove side surface of the groove, and the first-side inclined surface and the second-side inclined surface are inclined in different directions from each other.

The invention relates to a pneumatic vehicle tire with a tread with at least one circumferential groove, which is formed to the profile depth and has a groove base and groove flanks, wherein free-standing webs, which are at a distance from one another in the circumferential direction, are elongate in the circumferential direction and have a top surface running parallel to the tread periphery and a height of 7% to 30% of the profile depth, are formed on the groove base, wherein at least one protrusion, which sits on the groove base and is elongate in the circumferential direction, is formed between successive webs in the circumferential direction on and along each groove flank, wherein the one protrusion overlaps the other protrusion with respect to the circumferential direction, at least in portions, so that between the protrusions there remains a groove-base channel, which has a constant width in the axial direction between protrusion edges which are formed on the protrusions and run at a constant depth and in the circumferential direction.

A tire comprises a tread portion 2 comprising a shoulder main groove 5 extending on a side of a tread edge Te and comprising inner and outer groove walls 11 and 12. The inner groove wall 11 has an angle 1 with respect to a tread normal line in a cross section of the shoulder main groove 5 periodically increasing and decreasing in a tire circumferential direction so as to comprise concave and convex wall portions 16 and 17 arranged alternately in the tire circumferential direction. The outer groove wall 12 has an angle 2 with respect to a tread normal line in the cross section periodically increasing and decreasing in the tire circumferential direction so as to comprise convex and concave wall portions 22 and 21 arranged alternately in the tire circumferential direction. The angle 2 is larger than the angle 1 in any cross section of the groove.

Provided is a pneumatic tire which can fundamentally prevent the phenomenon in which cracks are generated in the bottoms of grooves and the areas where the side walls of blocks meet the bottoms of grooves, can suppress irregular abrasion of the tread, can enhance the overall rigidity of the tread, and can also enhance the drainage performance. The pneumatic tire of the invention includes a tread, side walls and bead sections, with a large number of blocks compartmentalized by grooves being formed on the surface of the tread, and also includes reinforcing ribs that are positioned inside a groove and have their lower parts joined with the bottom of the groove, with one lateral surface of a reinforcing rib and one side wall of the groove being in contact.

In a pneumatic tire having main grooves extending in a tire circumferential direction and land portions partitioned by the main grooves in a tread portion, a plurality of protrusions are disposed at a groove bottom of the main groove at intervals in a groove length direction, and a side surface portion of the protrusion is connected to a side surface portion of the land portion via a connecting portion having a height equal to or less than a height of the protrusion and a width narrower than a width of the protrusion.

A tire 1 according to the present invention comprises: a circumferential groove 12 formed in a tread portion; a land portion 22 divided by the circumferential groove 12; and transverse grooves formed in the land portion. The transverse grooves comprise a first transverse groove 32 dividing the land portion into several blocks, and a second transverse groove 51 dividing a block 42 divided by the first transverse groove into a first block portion 61 and a second block portion 62. A groove depth of the circumferential groove contacting the second block is smaller than the groove depth of the circumferential groove contacting the first block.

The invention includes tire treads, tires incorporating such treads, and methods for forming the same with a reduced undertread thickness. The treads include a length, a thickness, and a width, the width extending transverse to a direction of the tread thickness and a direction of the tread length. The treads further include a void extending into the tread thickness by a depth to a bottom side of the void, the void having a length and opposing sides spaced apart to form a void width. Yet further the treads include a ridge arranged along the bottom side of the void and protruding outward from the bottom side by a ridge height, the ridge also having a ridge length extending at least substantially continuously along the substantial length of the void.