Abstract: A tire (10) for driving on ice, comprising: a tread (20) having a rolling surface with a groove, a stud (30) with a part (31) thereof projecting from the rolling surface and having a minimum cross section Sm; a conduit (200-205) that forms, on the rolling surface of the tire, two opposing edges (211, 221; 212, 222; 213, 223), the conduit opening into the groove and/or onto a lateral face of the tread; wherein, for each stud, the sum of the mean cross sections Sn of the conduits, each mean cross section Sn being measured at right angles to one of the opposing edges formed by the conduit, is greater than or equal to half the minimum cross section Sm of that part of the stud that projects from the tread.

Abstract: A tire (pneumatic tire 1) provided with regularly arranged concave portions (concave portions 80) dented toward a tire inner side direction from a tire surface (tire surface 50) in at least some areas on the tire surface wherein in a direction along with the tire surface, a maximum width L of the concave portion is in a range of 0.1 micrometer or more to less than 50 micrometers, a depth D reaching to a point of the innermost part of the concave portion toward the tire inner side direction from the tire surface is within a range of 0.1 micrometer or more to less than 10 micrometers, in the direction along with the tire surface, an arrangement interval P of the concave portions is within a range more largely than 0.1 micrometer to less than 100 micrometers.

Abstract: A tire includes a tread provided with blocks formed among substantially longitudinal and transverse grooves, wherein among the blocks particularly broad intersections are formed, for example, by staggering substantially transverse grooves of circumferential rows axially in side-by-side relationship, of blocks with rounded corners, and wherein, inside such broad intersections, a stocky-shaped protrusion is arranged which has a lateral stiffness greater than the lateral stiffness of the surrounding blocks.

Abstract: A pneumatic tire is provided with a tread, a pair of sidewalls, and a pair of beads. A plurality of bending grooves are provided in an intermediate land located on the inner side of each shoulder main groove. Each of the bending grooves has one end portion opening to the shoulder main groove and the other end closed in the intermediate land. Each of the bending grooves is composed of a first tilting groove portion extending from the opening end portion to the bending portion and a second tilting groove portion extending from the bending portion to the closed end portion. The direction oriented from the opening end portion of the first tilting groove portion toward the bending portion coincides with the rotational direction, and the second tilting groove portion is bent toward the first tilting groove portion with the bending portion serving as an apex.

Abstract: A pneumatic tire, having in a tread surface thereof a pair of circumferential grooves formed on respective sides of the tire equatorial plane in the middle, a rib-like central land portion row demarcated by the circumferential grooves, and a plurality of lateral grooves extending between the central land portion row and each tread end, comprises in each half region of the tread: a row of first intermediate blocks each having a circumferential length D2 and demarcated by the lateral grooves, the corresponding circumferential groove, and first longitudinal grooves; and a row of second intermediate blocks demarcated by the lateral grooves, the first longitudinal grooves, and second longitudinal grooves, wherein facing openings of the first/second longitudinal grooves adjacent in the tire circumferential direction are offset from each other, and provided that D1 represents a circumferential distance between adjacent ends of the adjacent first and second intermediate blocks, D1?D2/2.

Abstract: A pneumatic tire includes a tread portion provided with at least one zigzag main groove extending continuously in a circumferential direction of the tire with a plurality of zigzag corners. The main groove includes a groove bottom and a pair of groove edges. The groove bottom extends in a zigzag manner in the circumferential direction of the tire with a first amplitude. The groove bottom has a width varying periodically so that a maximum width portion and a minimum width portion appear in turn at the zigzag corners. Each of the groove edges extends in a zigzag manner in the circumferential direction of the tire with a second amplitude, wherein the first amplitude is greater than the second amplitude.

Abstract: An aircraft tire has: plural ribs, (a wide rib, narrow ribs) that are provided at a tread portion, and that are demarcated by circumferential direction grooves that extend in a tire circumferential direction; and sipes that are formed in a tire transverse direction in the respective ribs, and that have tire circumferential direction positions that differ in ribs that are adjacent to one another in the tire transverse direction.

Abstract: A pneumatic tire comprises a carcass layer, a belt layer disposed on an outer side of the carcass layer in a tire radial direction, and a tread rubber disposed on the outer side of the belt layer in the tire radial direction. The belt layer is formed by laminating a pair of cross belts having a belt angle, as an absolute value, of not less than 10° and not more than 45° and having a belt angles of mutually opposite signs, and a circumferential reinforcing layer having a belt angle within a range of ±5° with respect to a tire circumferential direction. A tread width TW and a total tire width SW have a relationship such that 0.79?TW/SW?0.89.

Abstract: A pneumatic tire has inner mediate land portions and center land portion(s) that are divided into a plurality of blocks by lateral grooves. Each of the lateral grooves includes a pair of wide portions opening to a main groove and a narrow portion coupling the pair of the wide portions. one-side-closed sipes are formed in a bottom of each of the lateral grooves formed in the inner mediate land portions. The one-side-closed sipes are open at the wide portions and close at the narrow portion. a both-sides-open sipe is formed in a bottom of each of the lateral grooves formed in the center land portion or portions. The both-sides-open sipe is open at the wide portions and at the narrow portion.

Abstract: A pneumatic tire that lowers a temperature of a tread portion by promoting heat dissipation thereof is provided. On a tread surface, a narrow groove is formed extending in a direction inclined with respect to a tire circumferential direction and having a width smaller than a depth, and an inflow portion opening to the tread surface is also formed on at least one of walls of the narrow groove facing each other in the tire circumferential direction.

Abstract: A tire includes a circumferential direction main groove on a tread surface, first and second circumferential supplemental grooves located on both sides of the circumferential direction main groove, and first and second central land portions formed between the circumferential direction main groove and the first and second circumferential direction supplemental grooves. The first and second central land portions have plural width direction sipes, respectively, and each of the width direction sipes extends to the circumferential main groove, the circumferential main groove has shallow grooved portions and deep grooved portions. The deep grooved portions are deeper than the shallow grooved portions, and the shallow grooved portions are shallower than the circumferential supplemental grooves.

Abstract: A heavy duty pneumatic tire includes a tread portion provided with at least one circumferentially extending main groove, at least one circumferentially extending sub groove, and a plurality of lateral grooves to form repeated pitch elements each of which consists of one lateral groove and a block element. The sub groove includes a shallow bottom part with a depth smaller than that of the main groove. The shallow bottom part of the sub groove is provided with a groove bottom sipe. The lateral grooves include a shallow bottom part with a depth smaller than that of the main groove. The shallow bottom part of the lateral groove is provided with a groove bottom sipe. The lateral grooves have groove widths W2 in a range of from 5% to 15% in relation to a circumferential length L1 of the pitch element.

Abstract: The pneumatic tire has main grooves; land portions which are sectioned by the main grooves; paired notches which face to each other as well as being open to a tread surface; the notches being concave portions which are formed in side surfaces of two land portions which are adjacent across the main grooves; tie bars which protrudes at a predetermined height from groove bottoms of the main grooves and connect between the paired notches; and dimples which are provided in the middle in a width direction of the tie bars. The dimples are arranged at least in a notch internal region which is surrounded by wall surfaces of the notches among the tie bars.

Abstract: A tire tread is provided having a layered design that includes bridged and unbridged circumferential grooves during earlier stages of tread life while transverse and unbridged circumferential grooves are provided at later stages of tread life. Together, the combination of grooves can provide desired wet adherence performance without unacceptable compromises of tread wear and/or rolling resistance. Pockets can also be provided at the end of the transverse grooves to increase the volume available for receipt of water during wet traction.

Abstract: A pneumatic tire including a tread portion, side wall portions, and bead portions, wherein the tread portion includes a plurality of circumferential grooves having a groove width of not less than 3.0 mm and which extend in a tire circumferential direction while meandering, and a plurality of lateral grooves having a groove width of not less than 3.0 mm and which communicate between a pair of circumferential grooves adjacent in a tire width direction. The circumferential grooves and the lateral grooves partition two rows of polygonal blocks formed by arranging a plurality of polygonal blocks, having a polygonal shape with not less than five corners, in a staggered manner along the tire circumferential direction. A polygonal rib extending in the tire circumferential direction is disposed between the two rows of polygonal blocks. The polygonal rib is adjacent to the two rows of polygonal blocks.

Abstract: A pneumatic tire has a tread portion 2 provided with: an outboard shoulder main groove 4 and an outboard crown main groove 6 extending circumferentially of the tire; first outboard shoulder axial grooves 12a extending from an outboard tread edge Teo to the outboard shoulder main groove 4; second outboard shoulder axial grooves 12b extending from the outboard tread edge Teo and terminating without reaching to the outboard shoulder main groove 4; first outboard middle axial grooves 16 extending from the outboard shoulder main groove 4 and terminating without reaching to the outboard crown main groove 6; and second outboard middle axial groove 22 extending from the outboard crown main groove 6 and terminating without reaching to the outboard shoulder main groove 4. The first outboard middle axial grooves 16 are aligned with the first outboard shoulder axial grooves 12a, respectively, so as to smoothly continue to the first outboard shoulder axial grooves 12a through the outboard shoulder main groove 4.

Abstract: Disclosed herein is an example of a tire, and arrangements of multiple tires for a heavy goods vehicle having a tread provided on one side of the equatorial median plane with a sculpture of a first kind and on the other side of the equatorial median plane with a sculpture of a second kind, the first kind of sculpture comprising at least three grooves of generally circumferential orientation. The tired disclosed herein is provided to avoid having to change tires at the change of season, notably of the arrival of winter, on a heavy goods vehicle and more particularly on the drive axles of the said vehicle for which these changes require additional work.

Abstract: A tread made of rubber-like material for a tire for winter travel having a plurality of blocks of a height H, each block comprising a contact face designed to come into contact with the ground when the tire travels and at least one lateral face, said lateral face being covered by a layer of covering material over at least 50% of the surface thereof, and a leading zone designed to come into contact first with the ground when the tire travels, and said block has an oblique direction of extension (J) such that the leading zone of said block is a leading corner, and a part which is not covered by the covering material, said covering material having a modulus of elasticity which is greater than the modulus of elasticity of the rubber-like material forming the block, said uncovered part extending from the leading corner over at least ? of the height H of the block.

Abstract: An object of the present invention is to provide a pneumatic tire capable of significantly increasing the possibility that the tire can be recycled as a base tire for a retreaded tire without so much sacrificing a product life of the tire prior to retreading.

Abstract: A tire is provided having a tread region that includes continuous ribs which extend diagonally across the transverse direction of the tire. Partial sipes are provided at the trailing edges of the ribs. Full sipes can also be provided with the partial sipes. The ribs may form various patterns such as e.g., an S-shaped pattern, chevron pattern, and others. The tire provides improved traction performance over non-diagonal ribs while still providing desirable rolling resistance performance and control of irregular wear.

Abstract: A pneumatic tire is provided in the tread portion with a central land portion between two crown main grooves. The central land portion is provided with notches each having a depth of 55% to 65% of the depth of the crown main groove and having a closed end and an open end opening to the crown main groove. The maximum axial length of the central notch is 10% to 15% of the maximum axial length of the central land portion, and the circumferential length of the opening is 10% to 15% of one circumferential pitch of the shoulder block row 7R. The circumferential length of the opening is 15% to 25% of one circumferential pitch of the central notches.

Abstract: Various embodiments of a tire having grooves comprising sipes or other cross-groove negative geometry are disclosed.

Abstract: Tread rubber forms a ground contact surface. When the ground contact surface is divided into two parts: a mounting inner side and a mounting outer side, the tread rubber has an inner cap part that forms an inner ground contact surface and is produced from non-conductive rubber, and an outer cap part that forms an outer ground contact surface. The inner cap part has a branched conductive part that is formed from conductive rubber ranging from the ground contact surface of a mounting outer end of the inner cap part to the side surface or bottom surface of a mounting inner end while branching off at a plurality of positions. The outer cap part does not have branched conductive rubber. The branched conductive part is formed from the conductive rubber with a rubber hardness different from that of the non-conductive rubber that forms the inner cap part.

Abstract: Method of determining the longitudinal pitch of blocks of a tread band having a raised pattern with a number of longitudinal grooves and transverse grooves; the method including the step of calculating a best longitudinal pitch of the blocks, to minimize pass-by noise at a given target speed, as a function of the resonance frequency of the longitudinal grooves and an integer greater than zero.

Abstract: A pneumatic tire includes a tread portion provided with three to five circumferentially extending main grooves and a plurality of lateral grooves, to form a plurality of block rows each of which includes a plurality of tread blocks. Each tread block includes a ground contact surface with a polygonal shape that has at least five sides and each interior angle of not less than 90 degrees. Each ground contact surface of the tread block includes a maximum axial width W1 positioned between its circumferentially both ends, a circumferential length L1 between its circumferentially both ends, and a ratio W1/L1 of the maximum axial width W1 to the circumferential length L1 in a range of from 0.6 to 0.9.

Abstract: Provided is a pneumatic tire with a tread pattern that includes two first circumferential main grooves, shoulder land portions, shoulder lug grooves, shoulder sipes, and narrow circumferential grooves, the shoulder lug grooves being closed off midway in the region of the shoulder land portions without connecting with the first circumferential main grooves and including first regions and second regions that are disposed in the regions closer to the first circumferential main grooves than the first regions and have a groove depth that is less than that of the first regions. The shoulder sipes are connected with the second regions and extend toward the first circumferential main grooves. The narrow circumferential grooves extend in the tire circumferential direction and have a groove width that is less than the groove width of the shoulder lug grooves. The narrow circumferential grooves intersect with the second regions of the shoulder lug grooves.

Abstract: A pneumatic tire reduces the columnar resonance noise of the tire while controlling the lowering of wet performances, wherein four circumferential grooves continuously extending in the circumferential direction of the tire are disposed in a treading face and a plurality of lateral grooves each having one end opened to the circumferential groove and terminated in a land portion are formed with respect to two circumferential grooves among the four circumferential grooves, and these lateral grooves and the respective circumferential grooves have such a groove width that both groove walls of the groove do not contact with each other in a ground contact face and one or more lateral groove are always completely included in the ground contact face, and an extending length of a portion of each lateral groove in the ground contact face having a groove width of the lateral groove corresponding to not less than 30% of a groove width of the circumferential groove is made not less than 40% of an extending length of the ci

Abstract: A mold element for molding and vulcanizing a tire tread having a plurality of raised elements, each raised element having a contact face intended to come into contact with a road surface and lateral faces connected thereto. The mold element comprises cutting blades able to cut a cover layer already applied to a green form of the tire. Each cutting blade comprises a body, at least one of the cutting blades comprises a protrusion projecting from this body, able to drive a cut part of the cover layer into the depth of the green tire to cover all or part of a lateral face of a raised element. The cutting blade comprises, at one end of the body, a cutting edge forming an acute angle ? for cutting the cover layer.

Abstract: A tire (1) is provided with multiple projection parts (500) in a groove bottom (50B2) of a groove portion. The projection parts (500) extend from one side wall (50B1) to the other side wall (50B3) opposed to the one side wall (50B1), the side walls forming the groove portion. The projection parts (500) are arranged at predetermined intervals in the groove portion. A relationship of 0.75 L?P?10 L is satisfied where L denotes a length of the projection parts (500) and P denotes the predetermined intervals. In addition a relationship of 0.4?FW/W<1 is satisfied, where W denotes a groove width of the groove portion and FW denotes a length of the projection parts (500) in an orthogonal direction which is orthogonal to the extending direction of the groove portion.

Abstract: A tyre for a motor vehicle includes a tread and two shoulders. The tread includes a circumferential row of blocks between first and second circumferential grooves. Each of the blocks is delimited by a section of the first circumferential groove and by first and second transverse grooves that terminate at a common vertex spaced from the second circumferential groove. The common vertex is separated from the second circumferential groove by a continuous circumferential tread rib. The second transverse groove delimits one of the blocks and is separated from the first transverse groove that delimits a circumferentially adjacent block by a solid tread portion. The solid tread portion extends from the first circumferential groove to the continuous circumferential tread rib. The common vertex of each block is located at a position axially intermediate the first circumferential groove and a portion of one of the transverse grooves that delimits the block.

Abstract: Tire for motorcycles, having a tread band includes a central annular portion symmetrically located astride an equatorial plane and two shoulder annular portions located on axially opposite sides with respect to the central annular portion. The tread band has a void-to-rubber ratio not greater than 25%. The central annular portion has an axial extension not greater than 65% of the axial development of the tread band and the central portion has at least one module circumferentially repeated. Each shoulder portion has an axial extension not greater than 40% of the axial development of the tread band and the module includes at least one pair of first grooves with substantially circumferential course, at least partially located on opposite sides with respect to the equatorial plane. The central annular portion has a void-to-rubber ratio not smaller than 10% and the module includes a plurality of second grooves located substantially transversally with respect to the equatorial plane.

Abstract: A layer of cellular material forms a running layer (14A) of a tread (14) in which tread pattern elements (20, 22, 26) are made. In order to form the cellular material, an uncured blank is provided with a mass of material comprising p,p?-oxybis(benzenesulphonyl hydrazide) that forms a pore-forming agent. The uncured blank is placed in a vulcanization mold (28) comprising molding elements (30, 32, 34). At least 95% of the molding elements (30, 32, 34) each satisfy the following two conditions: a) the molding element (30, 32, 34) is separated from at least one other molding element (30, 32, 34) by a distance, expressed in millimeters, of less than or equal to DM=6.85+0.0065T3, T, greater than or equal to 3 phr, being the amount of p,p?-oxybis(benzenesulphonyl hydrazide) in the mass of material intended to form the cellular material, b) the molding element (30, 32, 34) is intended to form a tread pattern element (20, 22, 26) having a depth at least equal to 80% of the thickness of the running layer (14A).

Abstract: In a tread part (1), a tilted land portion (200) is divided into multiple blocks by a tilted narrow groove (300) and branched narrow grooves (350). Tilted main grooves (100) include an upper tilted main groove (101) and a lower tilted main groove (102). The branched narrow grooves (350) include first branched narrow grooves (350a) and second branched narrow grooves (350b). First blocks (210) and second blocks (220) have quadrilateral or pentagonal shapes. Of the first blocks (210), one first block and another first block adjacent to the one first block in a tilt direction KC have the same shape. Of the second blocks (220), one second block and another second block adjacent to the one second block in the tilt direction KC have the same shape.

Abstract: A tread profile of a vehicle tire has profile positives such as profile blocks or tread bands that have sipes. The sipes have an approximately ?-shaped geometry in plan view having two axial sections which are arranged approximately in an axial direction and which are arranged on a common, imaginary straight line with a spacing (a) to one another; a central bulge arranged between the axial sections, wherein the bulge has a maximum extent (b) measured in the axial direction; and, wherein a<b, such that undercuts are formed.

Abstract: A tread for a pneumatic tire in which air column resonance sound is reduced and wear of the groove fences and tread portion are caused to be approximately the same, while drainage performance is maintained, wherein a plurality of groove fences are formed and are installed within at least one circumferential groove, extending from the bottom of the circumferential groove, and block at least 70% of the cross-sectional area of the circumferential groove, and the bending parameter of the groove fences, defined as E·I/(h3l) (where E is the modulus at 10% elongation of the material used for the groove fences, I is the second moment of area of the groove fence, h is the height of the groove fence, and l is the width of the groove fence) is at least equal to 250 Pa and at most equal to 350 Pa.

Abstract: A tire is provided with multiple projection parts in a groove bottom of a groove portion. The projection parts extend from one side wall to the other side wall opposed to the one side wall, the side walls forming the groove portion. The projection parts are arranged at predetermined intervals in the groove portion. Lateral groove portions that extend from the groove portion to a buttress section, and have openings in the buttress section are formed. Air supply mechanisms that supply air to the lateral groove portions are formed.

Abstract: In a pneumatic tire 1, a side surface (101), on a buttress portion (14) side, of a land portion block (100) is inclined to the inside of the land portion block (100). The length (Lb1), in a tread width direction, of an and portion (100B) of the land portion block (100) is smaller than the length (La1), in the tread width direction, of an end portion (100A). The end portion (100B) is located at a rear side in a rotational direction (R) in which the pneumatic tire (1) installed on a vehicle rotates when the vehicle moves forward, and the end portion (100A) is located at a front side in the rotational direction (R).

Abstract: A tread portion of a pneumatic tire includes inner land portions between outer circumferential main grooves disposed most on tread ground-contact end sides and at least one inner circumferential main groove on the inner side thereof. The inner land portions are divided into inner blocks by inner lateral grooves inclined at an angle ? of 10 to 40°. The inner lateral grooves consist of first inner lateral grooves and second inner lateral grooves which are alternately arranged in a circumferential direction. The first inner lateral grooves include a wide-width part connecting to the outer circumferential main groove and a narrow-width part connecting to the inner circumferential main groove.

Abstract: The present invention provides a kerf structure for a snow tire, including unit structures on each of which spiral-shaped protrusions are continuously formed to be spaced a predetermined distance apart on the outer circumferential surface of a semi-cylindrical shaped column, wherein the continuously formed unit structures are arranged by alternating convex and concave portions in a zigzag formation, which is capable of optimizing the rigidity which can maintain gripping force as an original function of a kerf while ensuring a friction force generated from small blocks of a tread portion partitioned with kerfs by collapsing a block at an optimum level and further ensuring the kerf function on snow even in the last stages of tread wear by lowering the rigidity of the blocks of the tread portion.

Abstract: A pneumatic tire has a tread portion provided with two crown main groove and two shoulder main grooves and divided into a center land zone, two middle land zones and two shoulder land zones. The middle land zone is provided with middle auxiliary grooves. The shoulder land zone is provided with shoulder axial grooves. The width of the shoulder axial groove at the axially outer end is more than the width of the shoulder axial groove at the axially inner end. Through the shoulder main groove, the shoulder axial grooves are continued to the respective middle auxiliary grooves.

Abstract: A pneumatic tire includes, on a tread surface (1) of the tire, at least two longitudinal grooves (2, 3) extending along a tire equator (C), a plurality of transverse grooves (4a to 4d) connecting the longitudinal grooves, and a block row (L5) formed by a plurality of blocks (5a to 5d) extending along the tire equator and defined by the longitudinal grooves and the transverse grooves. Each of the blocks (5a to 5d) includes a reduced thickness portion (6) in an overlapping region (R) where the blocks overlap in projection when the block row (L5) is projected in the circumferential direction, the reduced thickness portion (6) including at least two portions where the thickness of the block gradually decreases.

Abstract: The invention controls irregular wear in the shoulder land portions and reduces the occurrence of cracking in the shoulder grooves of a pneumatic tire. To that end, the groove wall surface (17a) on the shoulder land portion (19) side of the shoulder groove (17) has an inclined surface consisting of a first inclined part (171) inclined toward the equatorial plane of the tire at an inclination angle ?1, which is constant along the circumference of the tire, and a second inclined part (172) further inclined from the first inclined part (171) toward the equatorial plane of the tire and reaching the groove bottom (17b) of the shoulder groove (17) at an angle ? with respect to the first inclined part (171), which varies along the circumference of the tire. Also, the inclination angles of the first and second inclined parts (171, 172) are set such that the maximum value ?max and the minimum value ?min of the angle ? satisfy (D?d) (tan ?max?tan ?min)?2.

Abstract: Sipe groups including a plurality of sipes which is opened to a main groove and is arranged at intervals in a tire circumferential direction are formed in both land parts with the main groove being interposed therebetween. The sipe groups are arranged at intervals in the tire circumferential direction, and are shifted in the tire circumferential direction on both sides of the main groove.

Abstract: A pneumatic tire is provided in a tread portion with a center land portion which is defined between center main grooves and whose top surface has a certain area and a maximum axial width of 15% to 19% of a tread width. The center land portion is provided with axial sipes and recesses. The recess extends from the center main groove toward the tire equator, and has a depth of 60% to 80% of the depth of the center main groove. The total area of the recesses is 5% to 9% of the area of the above-mentioned top surface. The center land portion is formed as a substantially continuous rib.

Abstract: A pneumatic tire has a unidirectional tread pattern. The land ratio of an imaginary crown region 5A is 0.75 to 0.85. The land ratio of an imaginary middle region 6A is 0.65 to 0.75. Crown axial grooves 4A and middle axial grooves 4B are inclined to the intended tire rotational direction toward the axially inside of the tire. The widths of the crown axial grooves 4A and the middle axial grooves 4B are 4.0 to 7.0 mm. The width of the crown axial grooves 4A is more than the width of a central main groove 3A and less than the width of middle main grooves 3B.

Abstract: Plural lug grooves are formed that extend from an outermost circumferential direction groove towards a tire equatorial plane side and are disposed sloped with respect to the tire equatorial plane at intervals along the tire circumferential direction. Arc shaped communication grooves are formed in segment land portions arising from a land portion being segmented in the tire circumferential direction by the lug grooves. The communication grooves communicate between the lug grooves adjacent to each other in the tire circumferential direction.

Abstract: On the tread surface, land portions are defined by a pair of circumferential main grooves and divided, by circumferential narrow grooves 3 and multiple lateral grooves 4 connecting between the circumferential main groove and the circumferential narrow groove or between the circumferential narrow grooves, into block rows L each of which including polygonal blocks arranged in a tire circumferential direction, wherein a block arrangement having the polygonal blocks 5 arranged in a line-symmetric manner with respect to the tire equator as an axis of symmetry includes side regions R1, R2 facing each other across the tire equator C and displaced from each other in the tire circumferential direction by a phase difference of 0.2 to 0.4 times of a repetition pitch of a pattern of the block row.

Abstract: A pneumatic tire for heavy load has a tread, circumferential grooves (2) extending continuously in the tread circumferential direction, transverse grooves (5) opening to the circumferential grooves (2) adjacent each other in the tread width direction, and a block (6) defined by the circumferential grooves (2) and the transverse grooves (5) on a surface (1) of the tread. The block (6) is provided with one or more shallow grooves (7-9) having an average groove depth shallower than a groove depth of the circumferential grooves (2) adjacent to the block (6). The average groove depth of the shallow grooves (7-9) is greater than 20% and less than 80% of the groove depth of the circumferential grooves (2). At least one of the shallow grooves (7-9) opens to at least one of the transverse grooves (5) and the circumferential grooves (2) adjacent to the block (6).

Abstract: A pneumatic tire is disclosed, adapted to highly effectively combine on-ice and on-snow performances. The pneumatic tire includes block groups (G) formed by polygonal blocks (10), which are arranged closely in a tread portion (1). The polygonal blocks (10) are formed by grooves (9) including first groove (9a) with a groove width (W9a) between the polygonal blocks 10 neighboring with each other in the tire circumferential direction. The groove width (W9a) of the first grooves (9a) is larger than a groove width (W9b) of second grooves (9b) between the polygonal blocks 10 neighboring with each other with a zigzag pattern.

Abstract: A pneumatic tire includes a tread portion provided with a pair of center main grooves to define a center portion therebetween, a pair of shoulder main grooves arranged axially outside the center main grooves to define a middle portion between the center and shoulder main grooves, and middle lateral grooves to divide the middle portion into middle blocks. Each center main groove extends in a zigzag manner including inclined long sides and inclined short sides alternately arranged in a circumferential direction of the tire. The center portion is provided with at least six center sipes within a circumferential region corresponding to a pitch of middle lateral grooves. Each middle block has a circumferential length of 85% to 95% the pitch, and is provided with at least one middle sipe. The number of middle sipe on each middle block is five or less.