Abstract:
It is possible to reduce pulling-out resistance of a knife blade from a tire while highly securing fall-preventing effect on block. A tread portion 2 has a block 7 provided with sipeings 10. The sipeing 10 has a zigzag portion 11 in an opening edge shape J at a block surface S, and zigzag displacement portions which are displaced toward one end of a longitudinal direction Fn and the other end are alternately repeated to form the zigzag portion 11 in a depth direction. When displacement amounts of a zigzag displacement portion 15U on the side of block surface, a zigzag displacement portion 15L on the side of sipeing bottom and an intermediate zigzag displacement portion 15M in a direction Fv perpendicular to the longitudinal direction Fn are defined as W1, W3 and W2, the following expressions are satisfied. W1≧W2 0.7×W2≧W3>0
Abstract:
A pneumatic tire for use on iced and snowed road surfaces has a tread surface. The tread surface has a plurality of main grooves extending in a circumferential direction of the tire and a plurality of lateral grooves extending in a width direction of the tire. Blocks are defined by the main grooves and the lateral grooves. The blocks have a ground contact face which has a plurality of pairs of sipes comprising a left sipe and a right sipe extending in the tire width direction. The plurality of pairs of sipes are placed in a predetermined interval in the tire circumferential direction. Each of the left and right sipes of each pair extends from a width-directional center portion of the ground contact face of the block toward each way of the tire width direction so as to open its outer end to each side face of the block.
Abstract:
A pneumatic tire with a tread has at least two axially adjacent tread elements, the elements being separated by a groove and each element having opposing lateral sides. Connecting the axially adjacent tread elements is at least one traction biting element. The biting element has three continuous portions. The first portion extends along the lateral side of the first tread element. The second portion extends through the separating groove. The third portion extends along the lateral side of the second tread element. Each biting element forms at least two distinct edges along the lateral sides of each tread element and two distinct edges in the separating grooves.
Abstract:
An improved tire tread has tread elements which form a tread pattern exhibiting two or more peripheral grooves and a plurality of transverse grooves extending inward from the outer (ground engaging) surface of the tread. Preferably the transverse grooves extend across the peripheral groves, and there are at least four of the peripheral grooves. Along at least a major portion of one upper side of chosen ones of such grooves, the tread elements defining such groove side are formed with serrations extending inward of the groove from the tread surface at an acute angle to a radius of the tire and terminating short of the base of the groove. The serrated surfaces define an upper portion of the groove as an opening of increased area at the upper part of the groove intersecting the tread surface, and present a substantially increased traction area along the outer or open top of the groove. In modifications of this tread, the serrations may be along one side of one or more of a plurality of peripheral tread grooves, or the serrations may be may be along opposite sides of such one or more grooves.
Abstract:
Vehicle pneumatic tire with a rubber tread profile having blocks formed by circumferential grooves and transverse grooves. At least some of the transverse grooves are defined by first and second flank segments. The first and second flank segments have different angles with respect to a radial direction. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
Abstract:
An end of a block 18 formed on a tread surface of a tire is chamfered in such a manner that a curvature of a chamfer increases toward the end of the block. Accordingly, a ground contact pressure which usually increases locally at the end of the block 18 is equalized and handling stability of the tire improves. Particularly, since the curvature changes, the ground contact pressure can be controlled corresponding to an actual distribution of ground contact pressure. As a result, the ground contact pressure can be equalized still further and an improvement in handling stability of the tire is achieved.
Abstract:
A method for directional force correction of pneumatic tires that simultaneously corrects radial and tangential force exerted by the tire. The method allows for the correction of tangential force regardless of the rotational direction of the tire. This invention accomplishes this end through an improved force correction technique, wherein at least two rotary grinders are employed. In the inventive method, the rotational direction of one grinder is reversed in relation to the rotational direction of the other grinder(s). Therefore, at least one grinder will engage the tire in an “up-grinding” manner, and at least one grinder will engage the tire in a “down-grinding” manner. The result is that across the width of the tire's tread surface, some tread blocks will have a “heel-to-toe” appearance, while others will appear “toe-to-heel.” The effect is that, no matter what direction the tire is rotating while in use on an automobile, tangential force variation has been reduced.
Abstract:
A pneumatic tire. In a block 18 formed on a tread surface, a sipe 24 which is twisted at a predetermined angle from a surface portion 28 toward a bottom portion 30 is provided. Due to ground contact pressure exerted on a contact patch area 26, small blocks 18a to 18d rotate, so that adjacent small blocks abut each other with a strong force. As a result, leaning of the small blocks 18a to 18d is suppressed, and a contact patch area area on the contact patch area 26 increases, so that performance on ice and snow improves. Moreover, due to rotation of the small blocks 18a to 18d, a torque (SAT) for restoring the small block to an original shape is generated, so that SAT generated by steel cords can be suppressed.
Abstract:
A pneumatic tire which comprises a tread portion with a pair of tread edges, and a tire shoulder extending radially inwardly from one of the tread edges, provided with a curved surface comprising a convex curve, wherein, on a cylindrical surface centered on the tire axis and intersecting the curved surface, the convex curve swells axially outwards and has a curvature, and the curvature gradually diminishes towards the radially inside from the tread edge. It is possible that the tread portion is provided along the tread edges with a circumferentially extending rib and/or a circumferential row of blocks. In case of circumferential rib, the rib is provided with the curved surface comprising a plurality of the convex curves and a plurality of convex curves alternating therewith so that the curved surface is waved in the tire circumferential direction. In case of blocks in a circumferential row, it is preferable that each block is provided with the curved surface comprising at last one convex curve.
Abstract:
A pneumatic tire which comprises a tread portion with a pair of tread edges, and a tire shoulder extending radially inwardly from one of the tread edges, provided with a curved surface comprising a convex curve, wherein, on a cylindrical surface centered on the tire axis and intersecting the curved surface, the convex curve swells axially outwards and has a curvature, and the curvature gradually diminishes towards the radially inside from the tread edge. It is possible that the tread portion is provided along the tread edges with a circumferentially extending rib and/or a circumferential row of blocks. In case of circumferential rib, the rib is provided with the curved surface comprising a plurality of the convex curves and a plurality of convex curves alternating therewith so that the curved surface is waved in the tire circumferential direction. In case of blocks in a circumferential row, it is preferable that each block is provided with the curved surface comprising at last one convex curve.