Abstract: A tire tread band for medium/heavy duty motor-vehicles having circumferential grooves confining three pairs of respectively center, intermediate and shoulder ribs. Respective tread blocks are defined along the center and intermediate ribs and they are confined by transverse cuts. The center cuts impart a cusp-shaped end conformation and a hollow-shaped end conformation to the respective blocks, and the shapes of said end portions mutually match. The intermediate cuts run in the linear extension of the center cuts to give the respective blocks a rhomboidal configuration. The tire can be alternately associated with a driving axle or a driven axle, by merely reversing its direction of rotation, so that the following results are selectively achieved: an increase in the traction capability by the intermediate blocks or an increase in the directional capability as a result of the mutual wedging between the center blocks at the ground-contacting area.

Abstract: The present invention provides a truck tire with a siping geometry to protect the main ribs of the tire's tread by delaying the onset of irregular wear and the growth thereof. The improved tire tread comprises a plurality of main ribs formed by grooves extending generally circumferentially around an outer surface of the tire forming a tread width for contacting the supporting surface. A plurality of sipes, positioned on both lateral edges of each one of the main ribs, provide protection for the main ribs to delay the onset of irregular wear. A pitch length and a sipe length are both selected to be within a certain range of values, as well as a ratio of the sipe length to the pitch length is selected. The sipes are preferably narrow in width having a maximum width dimension of about 0.40 millimeter.

Abstract: A new pneumatic radial ply truck tire 10 for use on steering axles has a tread 12 with a pair of centerline grooves 14 and a pair of shoulder grooves 16 that divide the tread 12 into a pair of shoulder rows 24, a pair of riding rows 26 and a center row 28. Lateral grooves 20 divide the rows into block elements 22. The centerline grooves 14 and shoulder grooves 16 have top, middle and bottom potions 30, 32, 34 and 36, 38, 40. The top portions 30, 36 have straight sides 42, 48 that are angled at top angles A1, A2 respectively. The middle portions 32, 38 also have straight sides 44, 50 that are angled at middle angles A3, A4 respectively. To provide the grooves 14, 16 with a general V-shape, it is preferred that the middle angles A3, A4 be greater than their respective top angles A1, A2 respectively. The bottom portions 34, 40 are U-shaped and have bottom widths X1 and bottom depths D1, D2 respectively.

Abstract: A tire tread has a total of four circumferential ribs and three circumferential grooves. The four ribs include two intermediate ribs and two outer ribs, and the three grooves include a center groove and two outer grooves. The two intermediate ribs are between the center groove and the two outer grooves, and the outer ribs are on the opposite sides of the outer grooves from the intermediate ribs. Rib cross slots and cross sipes extend outwardly from the outer grooves into the intermediate and outer ribs in herringbone patterns. The cross slots and cross sipes extend less than the full width of the ribs to provide the intermediate ribs with circumferential inner portions adjacent the center groove that are devoid of cross slots. These circumferential inner portions of the intermediate ribs have a plurality of circumferentially-spaced cross sipes that do not intersect the center groove.

Abstract: A new pneumatic radial ply truck tire 10 for use on steering axles has a tread 12 with four circumferential grooves 14 that divide the tread 12 into a pair of shoulder rows 24, a pair of riding rows 26 and a center row 28. Lateral grooves 20 divide the rows into block elements 22. The centerline grooves 14 and shoulder grooves 16 have top and bottom potions 30, 32. The top portions 30 have straight sides 42 that are angled at top angles A1. The middle portions 32 also have straight sides 44 that are angled at bottom angles A2. To provide the grooves 14 with a general V-shape, it is preferred that the bottom angles A2 be greater than their respective top angles A1. Stone penetration protectors 34 are positioned within the circumferential grooves 34 to protect the tread 12 and the belt-package 13 from stone damage. The lateral grooves 20 that extend across the two riding rows 26 and the center row 28 have top portions 50 and bottom portions 52.

Abstract: The present invention provides a pneumatic tire having a tread portion comprising a plurality of axially spaced apart essentially longitudinal grooves separating essentially longitudinal ribs. On at least one of said ribs, transverse grooves or cuts repeat in the circumferential direction to form first and second land portions wherein the first land portions comprise blocks having a circumferential length greater than that of the second land portions. Said second land portion acts as a sacrificial bridge which provides traction improvement and minimizes undesirable surface anomalies during the service life of the tire.

Abstract: A heavy duty radial tire which comprises a radial carcass ply, a belt comprising at least two plies of cords laid at angles of 10 to 40 degrees to the tire circumferential direction, and a tread portion provided with circumferentially extending two shoulder grooves which divide the tread into a central region and a pair of shoulder regions, the tread profile being a convex curve in the central region but a concave curve in each of the shoulder regions, the concave curve passing radially inwards of a standard line at lest partially, and the standard line defined as a circular arc passing three points on the tread profile in the central region at the tire equator, the axially inner edge of the main groove and the middle thereof. Preferably, the distances To, Tt and Tm measured normally to and radially outwardly from the standard line to the tread profile at the axially outer edge of the main groove, the tread edge and the deepest point therebetween, respectively, satisfy Tt>To>Tm.

Abstract: A pneumatic radial tire which is excellent in drainage and capable of reducing air-column-tube resonance sounds in circumferentially extending grooves to decrease noises. The pneumatic radial tire comprises a tread provided thereon with a groove extending circumferentially in the circumferential direction of the tire and a vibration buffer wall having essentially an identical cross-sectional shape provided near the sidewall of said circumferentially extending groove, wherein the height of the outside edge of the vibration buffer wall in the radial direction of the tire is lower than the height of the outside edge of the circumferentially extending groove in the radial direction of the tire.