Abstract: A pneumatic tire having a tread with a block design suited for off-road use. The tire has a ground contacting tread portion with circumferentially extending grooves and laterally extending grooves comprising at least a portion of an S-shape, defining circumferentially extending rows of blocks. The blocks comprise a first, second and third portion; the laterally outer, first and third portions, having a trapezoidal shape, are linked together by the second portion, having a height which is lower than the height of said first and third portions. In a preferred embodiment the tread has six rows of blocks spaced by five circumferentially extending straight grooves.

Abstract: A pneumatic tire for preventing stones from being retained in the tread grooves whereby steps are provided on the lower half portion of the sidewalks of the grooves so as to extend from a side of the tread groove toward the center part thereof reducing the width of the groove in the lower part, and a plurality of narrow sipes are formed on end of the steps in a direction interesecting the tread groove.

Abstract: An uneven wear-resisting heavy duty pneumatic tire comprises main grooves continuously extending in a tread of the tire along a circumference thereof, land portions separated by the main grooves, and stepped zones each provided in the land. Each stepped zone has a surface located radially inside of the tread by a step a viewed sectionally. Each of said stepped zones is separated from the adajcent land portions via a pair of circumferentially extending grooves or narrow cuts. An uneven wearing-sacrificing portion is formed by the surface of the stepped zone. The uneven wear-sacrificed portion slide-contacts with the tread within the tread ground-contacting area for supporting the load exerted upon the tire.

Abstract: A tread for a tire having a mid-circumferential plane. The tread comprises a plurality of tread elements arranged in a circumferential array about the tire. The tread also comprises a plurality of transverse extending grooves. Each of the grooves separate a pair of circumferentially adjacent tread elements. An area moment of inertia is associated with each of the tread elements when viewed normal to the tread element. Each of the area moments of inertia have a respective pair of principle axes of inertia relative to the mid-circumferential plane. The angular orientation between any pair of principle axes of inertia of different tread elements is within a predetermined angular range of 40 degrees or less.

Abstract: A tread pattern for a vehicle tire has at least one circumferential longitudinal groove as well as transverse grooves starting from the longitudinal groove and defining tread blocks between the transverse grooves limiting the longitudinal groove laterally. In order to improve the transmission of driving and braking forces, the tread blocks each have a projection along the longitudinal groove at the center of the sidewalls of the tread blocks, extending from the tread surface to the bottom of the longitudinal groove.

Abstract: A pneumatic tire includes a plurality of blocks, each having a narrow area interposed between one set of two sipes which extend substantially in a transverse direction of the tire and wide areas positioned respectively at both sides of the narrow area across the sipes. An average distance H2 from a tire tread surface of the narrow area to bottom portions of the sipes is less than an average distance H1 from tire tread surfaces of the wide areas to the bottom portions of the sipes. Expanded portions may be provided at the bottom portions of the two sipes. A ratio W2/W1 of a length W2 of the narrow area in the transverse direction of the tire to a length W1 of the wide areas in the transverse direction of the tire may satisfy 0.50.ltoreq.W2/W1.ltoreq.0.95. A length, in the circumferential direction of the tire, of at least one side end portion of the narrow area may be longer than a length, in the circumferential direction of the tire, of a central portion of the narrow area.

Abstract: A directional pneumatic tire having improved wet traction has an annular aqua channel and curved lateral grooves which direct water from the footprint to the shoulder area of the tire to help prevent hydroplaning. The pitch boundaries between the portions of the tire on either side of the aqua channel may be skewed. The curved lateral grooves and the skewing reduce noise properties of the tire. In addition, the lugs may have rounded or radiused leading and trailing edges, and a leading groove wall angle of about 5.degree. and a trailing groove wall angle of about 1.degree., which are believed to reduce noise and irregular wear. The lugs contain slots which change direction within the lug and tie bars in the slots at each point where the slots change direction. The tread has non-skid depth of 0.75 to 1 cm (0.030 to 0.40 inch) and a ratio of non-skid to tie bar depth of 0.42.

Abstract: A directional pneumatic tire having improved wet traction is provided. The tread is divided into two annular portions, each annular portion comprising a plurality of block elements separated by lateral grooves. The block elements extend continuously from a shoulder area of the tire to a mid portion of the tread. The block elements have substantially circumferentially aligned notches in leading and trailing groove walls, wherein each notch is defined laterally by a narrow bridge of rubber. The tread has curved lateral grooves to direct water from the footprint to the shoulder area of the tire to help prevent hydroplaning. The pitch boundaries between annular portions of block elements may be skewed. The curved lateral grooves and the skewing reduce noise properties of the tire.

Abstract: An all season pneumatic tire under the present invention has at the tread section two main grooves which divide the tread width into three tread regions and which are formed substantially, in circumferential direction and in continuation. The distance (GD) between the aforementioned two main grooves, when the maximum width of the tire is TW, is expressed as 0.2TW.ltoreq.GD.ltoreq.0.5TW. Further, the width (GW) of each major groove is expressed as 0.02TW.ltoreq.GW.ltoreq.0.07TW. Further, each of the aforementioned major groove has jogs (JW) shifted tread-width-wise by an amount the same as or smaller than the groove width (GW), said jog width (JW) being expressed as 0.5 mm.ltoreq.JW.ltoreq.GW, and is formed substantially, in circumferential direction, and in continuation.

Abstract: A pneumatic tire manufactured with a sector mold including of plural arc-shaped segments each having plural island rows of ribs or blocks in its tread portion and sipes formed in at least one island row. Among these sipes, a depth of a sipe located in the vicinity of a position of a tread surface corresponding to an edge of the arc-shaped segment is made shallower than that of a sipe located at a position other than the above position.

Abstract: In order to optimize the behavior of a conventional passenger car on snow-covered and icy ground, the driving axle of said vehicle is equipped with tires the treads (1) of which are provided with elements in relief (11) having incisions (14) of a width other than zero, the traces of which are transverse while the load-bearing axle of the same vehicle is equipped with tires of the same structure but with treads (2, 3) provided with elements in relief or blocks (21, 31) having incisions (24, 34) of a width other than zero, the traces of which are elliptical.

Abstract: Tread for heavy vehicles with radial carcass comprising a plurality of cimferential rows of blocks (13) having incisions (15), defined by circumferential (10) and transverse (12) grooves, said blocks being connected to each other in circumferential direction by platforms 14) which are arranged in the transverse grooves (12) and the height of which increases from the center towards the edges of the tread, the depth of the incisions (15) decreasing from the center towards the edge of the tread and the density of the incisions being maximum in the central zone (Z) of the tread.

Abstract: In order to improve the compromise between the properties of adherence to ow-covered or icy ground and its wear properties, the tread of a tire which is provided with incisions having a width other than zero and, seen in cross section, fork-shaped traces with two branches, has grooves the walls of which are provided with an incision which forms with the trace of the groove a trace which is symmetrical to the trace of the incision which is parallel to and closest to said groove.

Abstract: A heavy load pneumatic radial tire which includes at least one carcass layer in a radial direction and a reinforcing belt comprising at least two layers of metal cords around the outer periphery of the carcass in a tread portion, and in which a plurality of ribs partitioned by a plurality of main grooves extending in a tire circumferential direction are formed in a main grounding region of the tread surface and a narrow groove having a groove width of 1.

Abstract: A radial-ply tire has a tread provided with at least one block isolated by longitudinal and transverse grooves. A central wavy sipe and a peripheral wavy sipe are disposed on the block, each of the wavy sipes running zigzag along a centerline, wherein the central wavy sipe makes a smaller angle with the centerline therefore than the peripheral wavy sipe with the centerline therefore.

Abstract: The high density siping zones reduce rib edge erosion wear by creating a weakened zone without the tendency of tearing.

Abstract: A tread for motor vehicle tires having circumferential grooves (3) and transverse grooves (4), a plurality of tread blocks (5, 6) circumferentially spaced apart to form two shoulder rows (5) and at least one central row (6) located between the shoulder rows. Each block (5, 6) is provided with one or more sipes or slits (11, 12) that are rectilinear and inclined with respect to the axis of rotation of the tire (2). The sipes (11, 12) of the blocks (5, 6) which constitute each of the shoulder and central rows are parallel to one another. The sipes (12) of the central rows (6) have an inclination, with respect to the axis of rotation, that is greater than the inclination of the sipes (11) of the blocks (6) which constitute the shoulder rows. This arrangement of the sipes (11, 12) substantially reduces the rolling noise of the tire.

Abstract: A tire tread (20) comprises four circumferentially extending grooves (1-4) dividing the tread into five continuous ribs (10-14) of elastomeric material. The edges of the grooves, which separate the different ribs from each other are constituted by zig-zag shaped repetitive design units (5-8;35-38). The repetitive design units on either side of the grooves (1-4) extend in circumferentially opposite directions and have each four legs, a first (5;35) and third (7;37) short leg alternating with a second (6;36) and fourth (8;38) long leg. The ribs include series of deep (40-42, 43-45) and shallow (50-52, 53-55) sipes as well as deep (48, 49) cuts.

Abstract: A winter type tire tread (11) comprises an uneven number of, but at least three, circumferentially extending axially spaced grooves (4-6) and a plurality of zig-zag shaped grooves (36, 37) disposed circumferentially about the tire in a repetitive manner and extending across the tread from the equatorial plane (EP) towards the lateral edges (TE.sub.1, TE.sub.2) of the tire. The zig-zag shaped grooves (36, 37) situated on one side of the equatorial plane (EP) are symmetrical to those situated on the opposite side of the equatorial plane. The circumferentially and laterally extending grooves (4-6, 36, 37) define block elements (20-23), arranged in circumferentially extending rows (30-33) and having each at least in part the shape of a parallelogram. A plurality of sipes (15) are incorporated in each block element.

Abstract: To prevent crack occurrence at groove bottoms on both side areas of foam rubber tread of all-season studless tires, the pneumatic tire having a tread surface portion composed of at least two outer and inner rubber layers is characterized in that the hardness of the inner rubber layer lies from 54 to 80 degrees in Shore hardness and is higher than that of the outer rubber layer, and further the outer rubber layer is made of foam rubber with a foam rate from 5 to 50% with at least 10% volume ratio with respect to tread volume. The outer foam rubber layer serves to improve tire performance on icy and snowy roads in winter, and the inner ordinary rubber layer serves to reduce change in groove width after vulcanization, that is, reduce dynamic strain concentration at lateral grooves and therefore to reduce crack generation at the lateral groove bottoms.

Abstract: The present invention relates to a radial tire and a radial tire-rim assembly. The radial tire (1) has a pair of beads (2), each bead having a bead core (3) and a bead apex (5), a carcass (4), with both edges thereof folded back around said bead core and fastened to said bead core, a tread (6), a belt layer (7), and an aspect ratio smaller than 60%. The tread is wider (in the axial direction) than the maximum width of said carcass and the edges of said tread are positioned within a range of 50-100% of the height of the cross-section of the carcass. This structure provides the tire side with rigidity and permits the tread to deform so that is supports the weight of the car and runs safely even when the tire pressure is decreased.

Abstract: The tire treads (11) comprise an uneven number of axially spaced straight grooves (400-404) which extend circumferentially about the tire (10), the center groove (402) having its centerline on the equatorial plane (EP), and a plurality of circumferentially spaced laterally extending grooves (430-435), the axially innermost grooves (431-434) forming with the equatorial plane an angle comprised between 30.degree. and 60.degree., the two axially outermost grooves (430, 435) forming with the equatorial plane an angle comprised between 60.degree. and 80.degree.. The circumferentially and laterally extending grooves define rows of land portions having the shape of a large parallelogram adjacent to a small parallelogram. The small parallelogram has one of his small sides in the continuation of one of the sides of the large parallelogram delimiting a circumferentially extending groove (400-404).

Abstract: An uneven wear-resisting heavy duty pneumatic tire comprises main grooves continuously extending in a tread of the tire along a circumference thereof, land portions separated by the main grooves, and stepped zones each provided in the land. Each stepped zone has a surface located radially inside of the tread by a step a viewed sectionally. Each of said stepped zones is separated from the adjacent land portions via a pair of circumferentially extending grooves or narrow cuts. An uneven wearing-sacrificing portion is formed by the surface of the stepped zone. The unever wear-sacrificed portion slide-contacts with the tread within the tread ground-contacting area for supporting the load exerted upon the tire.

Abstract: A tire tread pattern for a radial ply heavy vehicle tire comprising at least two circumferentially extending continuous main tread grooves providing at each edge of the tread a shoulder rib characterized in that each shoulder rib comprises in its shoulder edge a narrow edge zone having, in cross section of the tire, a radial height at least 2 mm less than the ground engaging surface of the shoulder rib immediately adjacent to said edge zone and a junction zone between the edge zone and shoulder rib which is made flexible in both the transverse and circumferential directions by a series of circumferentially spaced narrow slots extending across the junction zone at an angle to the center line of the tread between 20 and 60 degrees, the slots having a width between 0.4 and 2.0 mm and the depth in the junction zone substantially the same as the main tread grooves.

Abstract: A pneumatic radial tire comprises a tread divided into 4 to 5 ribs by 3 to 4 main wide grooves each extending circumferentially of the tire. In this tire, at least one row of sipes isolated from the main grooves in the axial direction of the tire and arranged at an approximately equal interval in the circumferential direction of the tire is arranged in only a second rib viewed from the outside in the axial direction of the tire.

Abstract: A snow tire which has tread blocks provided with slits extending between the side edges of the block, and the slit comprises: the first part extending axially of the tire from one side edge toward the other side edge of the block; the second part extending axially of the tire from the said other side edge toward said one side edge of the block; and the third part extending obliquely with respect to the tire axial direction to connect the first part with the second part, wherein the depth of the slit is varied in the tire axial direction to form a shallow portion and a deep portion, the axial length of the first part is more than 0.25 times and less than 0.48 times the total axial length of the slit, the axial length of the second part is more than 0.25 times and less than 0.48 times the total axial length of the slit, the ratio between the axial length of the first part to the axial length of the second part is more than 0.8 and less than 1.2, the axial length of the third part is more than 0.

Abstract: A tread (10) for a tire has at least three wide grooves (13,14,15,16) therein. At least two zigzag ribs (19,20,21) are bordered by said grooves and have block elements (22) nested in the reentrant angles of the ribs and separated therefrom by narrow grooves (23). The wide grooves (13,14,15,16) well remain open in a footprint of a tire while the narrow grooves (23) will close up in a footprint of a tire. Tire treads according to the invention may be provided as precured retread material, as part of a newly manufactured tire, or as part of a retreaded tire.

Abstract: A tire tread with elastomeric ground engaging elements having an incision is described. The invention is characterized by at least one of the elements having an incision extending from the tread surface towards the interior of the elastomeric material. The incision splits into at least two incision portions in the interior of the elastomeric material below the tread surface. The incision portions extend away from the tread surface and diverge apart from each other over at least part of their depth.

Abstract: A heavy duty pneumatic tire comprises a tread portion having a pitch pattern and provided with at least two circumferential main grooves extending circumferentially of the tire, wherein at least one dimple is arranged in a region of an island part ranging from a side end of the tread to a position corresponding to not more than 20% of a tread width per one pitch, and a pair of sipes are disposed at opposed positions of each dimple to a widthwise direction of the tire so as to extend in the widthwise direction of the tire. This dimple has a particular ratio of opening size in widthwise direction to opening size in circumferential direction, a size of not more than 8 mm, a particular depth, and a particular total opening area ratio per one pitch.

Abstract: Certain elements in relief (11, 13) of a tread (1) for a radial tire are vided at least with incisions (41, 42, 43) which in cross-section have a fork-shaped outline with at least two branches (41B, 41C) forming an extension of a single part (41A), the number of incisions (41) in the element in relief (11, 13) being multiplied by a factor equal to at least 1.5 starting from the depth (h.sub.1) of the double-branched incision (41). Use of such treads for tires intended to travel on wet, snow-covered or icy ground.

Abstract: A pneumatic tire comprises a plurality of main grooves in a tread of the tire. The main grooves substantially circumferentially extend and are spaced apart from each other in an axial direction of the tire. Each the main groove is continuous. Intersection angles between an equatorial plane of the tire and tangents to each the main groove are larger from a starting end to a terminal end of the main groove opening at a tread end of the tire. Th pneumatic tire further comprises a plurality of sipes in a tread of the tire. The sipes extend substantially in axial directions of the tire but are inclined relative to the equatorial plane of the tire and spaced apart from each other in circumferential directions. Each the sipe is inclined with its opening directing forward in a rotating direction of the tire.

Abstract: A pneumatic tire has a tread region and a pair of shoulder regions, one extended radially inwardly from each tread edge, and the tread region is provided with a pair of circumferentially extending shoulder ribs, and the shoulder regions are provided with buttress hollows arranged circumferentially at intervals, wherein at least one of the shoulder ribs is provided with circumferentially extending narrow grooves, which narrow grooves are arranged in the circumferential direction of the tire so that the circumferentially adjacent narrow grooves overlap with each other at their end portions, and the locations of the overlaps in the narrow grooves are coincident with the locations of the buttress hollows in the circumferential direction of the tire.

Abstract: A tread for a pneumatic tire featuring generally zig-zag ribs defined by wide grooves. Circumferentially extending slots in the ribs are located near the wide grooves. The circumferentially extending slots define an edge zone between the slots and the nearest wide groove and a primary-load zone on the opposite side of the slot. Located in the edge zone there is means for reducing the unit tread pressure in the edge zone as compared to such pressure in the primary-load zone. The circumferential slots together with the means for reducing the unit tread pressure act to provide a breakwater against the spread of irregular wear known as "river wear".

Abstract: To improve biased abrasion or traction and brake performance of a pneumatic tire formed with a great number of blocks partitioned by the main circumferential grooves and transverse grooves on the tread thereof, each of the block is formed with at least three sipes arranged regular intervals along the tire circumferential direction and extending over an entire width of each block along the tire transverse direction in such a way that at least one end of each sipe is open to the main circumferential groove and a central sipe of each block is formed the deepest as compared with other side sipes.

Abstract: A vehicle tire (10) has a tread (20) with a plurality of ribs (30,31,32) extending circumferentially about the tread. The ribs each have a pair of lateral edges (48,49;60,61) which comprise edge segments placed end to end to present a zigzag configuration. Each rib has grooves (37,38;39,40) therein which intersect the lateral edges of the respective rib and have varying depths at said lateral edges. Preferably, the tread has an all-season configuration.

Abstract: A pneumatic tire having improved wet performances is disclosed, which comprises a tread of a rib type pattern divided into three or more ribs by at least two circumferential grooves so that the tread defines both side regions and the remaining central region by a pair of the circumferential grooves arranged close to both side ends of the tread and is provided at each region with sipes. In this type of the tire, each of the sipes arranged on both side regions is inclined at a small angle with respect to the transverse line of the tire and each of the sipes arranged on the remaining central region is inclined at a small angle with respect to the circumferential line of the tire.

Abstract: A radial tire having a tread provided with a plurality of circumferential grooves extending circumferentially of the tire to form a rib pattern thereon, said tread having lateral side portions, each having a width of 10 to 35% of the tread width extending from each edge thereof, said side portions being provided with sipes arranged at intervals of 8 to 20 mm in the circumferential direction of the tire, said sipes each comprising a main portion inclined with respect to the axial direction of the tire at an angle of 5 to 25 degrees and an outer portion located axially outward of said main portion and extending axially at an angle of not more than 5 degrees to the axial direction of the tire, the axial length of said outer portion of each sipe being not more than 10% of the tread width and being not more than 50% of the axial length of the sipe.

Abstract: A pneumatic tire (10) has a tread portion (11) comprising a plurality of circumferentially extending grooves (21,22,23) which divide the tread into axially spaced lands (24,25,26,27). Each land is subdivided into blocks (32X,32Y) by cross-slits (31). The blocks in each land (24,25,26,27) are arranged so that circumferentially adjacent blocks (32X,32Y) are axially offset relative to each other. The cross-slits (31A,31B,31C) in each land alternate circumferentially between axially extending cross-slits (31B) and biased angle cross-slits (31A,31C). The axially extending cross-slits (31B) are sipes and the biased angle cross-slits (31A,31C) may be either sipes or grooves.

Abstract: In order to improve the wandering performance of a radial tire, that is, to increase the camber thrust, the camber torque and the self-alignment effort of the tire without degrading various performances required for the radial tire, the radial tire is formed with a plurality of main zigzag wide grooves extending in the circumferential direction of the tire; at least one auxiliary straight narrow groove disposed on the shoulder rib and extending in a circumferential direction of the tire; and a plurality of sipes arranged outside the auxiliary groove at regular intervals along the outermost circumferential edge of the tire and extending in the lateral direction of the tire from the outermost end of the tire to the auxiliary groove. The width W.sub.a of the auxiliary groove is 1 to 4% of that of the main grooves W.sub.m ; the outward inclination angle .theta..sub.

Abstract: A pneumatic tire (10) has a tread portion (11) comprising a plurality of circumferentially extending grooves (21,22,23) which divide the tread into axially spaced lands (24,25,26,27). Each land is subdivided into blocks (32X,32Y) by cross-slits (31). The blocks in each land (24,25,26,27) are arranged so that circumferentially adjacent blocks (32X,32Y) are axially offset relative to each other. The cross-slits (31A,31B,31C) in each land alternate circumferentially between axially extending cross-slits (31B) and biased angle cross-slits (31A,31C). The axially extending cross-slits (31B) are sipes and the biased angle cross-slits (31A,31C) may be either sipes or grooves.

Abstract: In order to improve the wear life of a tread having elements in relief which are provided with numerous incisions, each element in relief which is defined by circumferential grooves and transverse grooves comprises an even number of incisions which have rectilinear traces on the surface of the tread and, in cross-section, broken line or undulated line traces, the mean axes of which are perpendicular to the surface of the tread, and in such manner that the trace of one incision is identical to the symmetrical trace, with respect to its mean axis, of the trace of a circumferentially adjacent incision.

Abstract: A pneumatic tire having excellent traction and braking performances is disclosed, which comprises a tread divided into island portions inclusive of at least one block row group by plural circumferential grooves and plural transverse grooves, and having plural sipes. In this type of the tire, the sipe is provided at its cut end with an escape hole having a size larger than that of the sipe.

Abstract: A tread-pattern for tires, particularly for large-size tires destined for high-speed vehicles that have a great load-capacity. The tread-pattern is characterized by the presence of a plurality of circumferential zig-zag grooves that divide the tread-band into longitudinal ribs and by means of a plurality of sipes that divide the central ribs into a circumferential succession of blocks which the sipe-profiles render mutually indented one into the other. The profile is a broken line constituted by three successive segments of which the initial and final ones constitute the extension of a portion of the zig-zag development of the longitudinal grooves, while the central one presents a greater circumferential development than the corresponding development between the end-points of the sipe.

Abstract: A tire tread comprises elements in relief which are provided with undulated or broken line incisions. These incisions, which are of a width of less than 1 mm, have smaller amplitudes at the bottom of the incisions than at the surface of the tread.

Abstract: A tire having a tread, wherein a polymer component in the rubber composition constituting the tread comprises at least 30% by weight of a specific styrene-butadiene rubber produced by solution polymerization (S-SBR), and wherein the pattern of the tread has a specific contact area ratio, lateral groove density and lateral siping density is suitable for an all-season tire having high-wet grip properties, low rolling resistance, excellent low-temperature characteristics, and excellent on-ice and on-snow performance at a highly balanced level and with no sacrifice whatsoever of abrasion resisting characteristics.

Abstract: A pneumatic vehicle tire which has fine slits in the tread. These slits are inclined relative to the circumferential direction of the tire. In order to increase the frictional connection to the roadway, to make the wear of the tread more uniform, and in addition to be able to use mechanically stiff plates for the associated vulcanization molds, the fine slits are twisted about an at least approximately radially extending twist axis. The fine slits preferably extend continuously from their roots into the tread surface region proper.

Abstract: A highly durable tread pattern of a rib type pneumatic tire using two grooves for heavy vehicles is disclosed. The tread is provided with a pair of zigzag grooves extending circumferentially of the tread and dividing the tread into a center rib and a pair of side ribs. The center rib is provided with a plurality of sipe grooves arranged in a row and substantially equally spaced on the circumference of the tread by a pitch corresponding to a pitch between the zigzag tread grooves. The center rib and the pair of side ribs do not interrupt their circumferential continuity. Each of the sipe grooves is composed of a circumferentially extending section inclined at an acute angle of smaller than 45.degree. with respect to the circumferential direction and a widthwisely extending section inclined at an angle of at least 45.degree. with respect to the circumferential direction. These sections are formed into hook-shaped, bracket-shaped or curve-shaped formation or a combination of these formations.