Abstract: A pneumatic tire includes a land portion provided in a tread portion and including a recess recessed inward in a tire radial direction. The recess includes three or more sides defining an opening that opens to a ground contact surface of the land portion and forming a polygon, and three or more side surface portions defined by the sides and line segments connecting respective vertexes of the sides and a bottom point provided on an inner side of the ground contact surface in the tire radial direction. The side surface portions are formed so as to approach the bottom point as the side surface portions extend inward in the tire radial direction from the ground contact surface.

Abstract: Provided is a tire including, in a tread surface, a plurality of land portions partitioned by a circumferential main groove extending continuously in a tire circumferential direction, on at least one side in a tire width direction, and comprising, in an internal land portion located in a vehicle-installed inside half portion to a tire equatorial plane among the plurality of land portions, an internal resonator including a first auxiliary groove that terminates in the internal land portion, and a first branch groove that communicates between the first auxiliary groove and the circumferential main groove, and in the first branch groove, a hidden groove having an opening width in the tread surface that is smaller than a groove width of a groove bottom is provided adjacent to the first auxiliary groove.

Abstract: Provided is a pneumatic tire that can be obtained without requiring complicated design and has improved noise performance. On the inner vehicle-mounting side, the circumferential pitch length of the tire has pitch variation comprising at least three pitch lengths and, if the number of pitches is n and the pitch lengths (Pi) are Pi1, Pi2, Pi3, . . . , Pin, in order from the greatest pitch length, the pitch lengths satisfy the relationships Pi1/Pi2?Pi2/Pi3? . . . ?Pin?1/Pin, and Pi1/Pi2.

Abstract: A shoulder land portion includes a main body land portion formed between a thin groove extending in a tire circumferential direction on a tire width direction inner side of a ground contact end and a shoulder main groove, and the main body land portion includes a contact region adjacent to the shoulder main groove provided along the tire circumferential direction and a non-contact region provided along the tire circumferential direction between the thin groove and the contact region. The contact region contacts a road surface in a normal load state, and the non-contact region is recessed to a tire radial direction inner side from a tread surface. The non-contact region does not contact the road surface in the normal road state, and when a length of the non-contact region is W1 and a length of the main body land portion both along the tire width direction is Rw, 0.2Rw?W1?0.5Rw.

Abstract: A processing device divides an initial tread pattern into multiple mutually adjacent partial patterns, each having a width smaller than that of the initial tread pattern, by at least one straight line along a circumferential direction of a tire. The processing device calculates variation amounts of characteristic values of the partial patterns with respect to the circumferential direction, based on a contact region, each of the characteristic values indicating a shape of a corresponding partial pattern. The processing device modifies the shapes of the partial patterns so as to reduce the variation amounts of the characteristic values of the partial patterns. The processing device relatively moves the partial patterns along the circumferential direction so as to reduce a total variation amount of characteristic values of at least two mutually adjacent partial patterns. The processing device combines the partial patterns with each other to generate a tread pattern of the tire.

Abstract: A tire includes a tread portion being provided with a pair of circumferentially and continuously extending shoulder main grooves and at least one crown main groove between the shoulder main grooves to form a pair of middle portions each of which is between adjacent one crown main groove and one shoulder main groove. Each of the middle portions is provided with a circumferentially and continuously extending longitudinal sipe, a plurality of inner middle sipes extending axially outwardly from the crown main groove and terminating without reaching the longitudinal sipe and a plurality of outer middle sipe extending axially inwardly from the shoulder main groove and terminating without reaching the longitudinal sipe. The number of the outer middle sipes is greater than the number of the inner middle sipes.

Abstract: Performance on snowy roads is improved. Provided is a pneumatic tire, of which the mounting orientation on a vehicle is indicated. An outer middle land part is formed between a first major groove and a second major groove. The first major groove has first portions and second portions alternately formed in the tire circumferential direction, the second portions being wider than the first portions. The outer middle land part is provided with a plurality of middle inclined grooves not directly interconnected with either the first major groove or the second major groove, a plurality of outer middle lug grooves connecting the second portions of the first major groove and the middle inclined grooves, and inner middle lug grooves connecting the middle inclined grooves and the second major groove. The outer middle lug grooves are provided to different positions in the tire circumferential direction than the inner middle lug grooves.

Abstract: A tire includes a tread having a first plurality of tread blocks on a first side of an equatorial plane and a second plurality of tread blocks on the second side. Each of the first plurality of tread blocks has a first leading lug wall, a first trailing lug wall, a first leading sipe proximate to the first leading lug wall, and a first trailing sipe proximate to the first trailing lug wall. Each of the second plurality of tread blocks has a second leading lug wall, a second trailing lug wall, a second leading sipe proximate to the second leading lug wall, and a second trailing sipe proximate to the second trailing lug wall. The first leading sipes have a depth greater that of the first trailing sipes. The second leading sipes have a depth less than that of the second trailing sipes.

Abstract: A pneumatic tire comprises a tread portion provided with a circumferential shoulder main groove, shoulder lateral grooves extending from the shoulder main groove toward a tread edge, and middle lateral grooves extending from the shoulder main groove toward a tire equatorial plane, the shoulder main groove extending in a zigzag manner through an axially innermost and outermost points alternately, each middle lateral groove extending from each innermost point of the shoulder main groove with an angle of 50-75 degrees with respect to a tire axial direction, and each shoulder lateral groove extending from the shoulder main groove with the same inclination direction with the middle lateral groove at an angle of 10-25 degrees with respect to the tire axial direction, wherein the number of shoulder lateral grooves is larger than the number of middle lateral grooves.

Abstract: A pneumatic tire having a tread portion including land portions formed by vertical grooves provided in a tire circumferential direction and lateral grooves provided so as to intersect with the vertical grooves, the lateral grooves being disposed in the tire circumferential direction having a plurality of pitches P1, P2, and P3, wherein in a shoulder region of the tread portion, as a pitch decreases a volume ratio of the lateral grooves with respect to a pitch volume thereof increases; and, in a center region of the tread portion, as a pitch decreases the volume ratio of the lateral grooves with respect to a pitch volume thereof decreases.

Abstract: A pneumatic tire has a tread portion divided into a crown rib, a pair of middle ribs and a pair of shoulder ribs by two crown main grooves and two shoulder main grooves. The width of the crown main groove is 5.5 to 7.5% of the tread width. The width of the shoulder main groove is 50 to 70% of the crown main groove width. The crown rib has crown sipes extending from the crown main grooves. The middle rib has axially inner middle sipes extending axially outward from the crown main groove and ending within the middle rib, and axially outer middle sipes extending axially inward from the shoulder main groove and ending within the middle rib. The shoulder rib has shoulder sipes extending axially outward from the shoulder main groove, and shoulder lug grooves extending axially inward from the tread edge ending within the shoulder rib.

Abstract: A tire includes a tread band provided with a tread pattern including a first and a second portion of tread pattern, repeated just the same along the circumferential extent of the tire, forming respectively a short pitch module and a long pitch module of the tread pattern, wherein the modules include a respective first transverse groove in which, starting from an axially outer first end thereof toward an opposed axially inner second end thereof, an initial section and a section of enlarged cross-section are formed, the latter being blind, at least on its axially inner side, when in the footprint area. The initial section and the section of enlarged cross-section have, respectively, a first width and a second width, and the ratio between the second width and the first width of a first transverse groove belonging to a short pitch module is greater than the ratio between the second width and the first width of a first transverse groove belonging to a long pitch module.

Abstract: In a tread part, a land part (block) partitioned by a main transverse groove is provided with a thin groove having a narrower groove width than the main transverse groove and extending in a tire width direction. On a groove lateral face which is one of opposing groove lateral faces of the thin groove, ridges projecting toward the other groove lateral face and extending in a depth direction of the thin groove are provided. A plural number of the ridges are provided in parallel to each other at intervals in a length direction of the thin groove, and an extending length in the depth direction is set up to include at least two kinds.

Abstract: The manufactured pieces are the ones both end surfaces thereof in the tire circumferential direction are cut from the pieces before cutting 1 and the pieces before cutting 1 have the cutting regions whose cross-sectional shapes in the tire width direction are the same at both ends of its circumferential direction. And in the cutting process of cutting the pieces for modifying the lengths in the circumferential direction from each of the pieces before cutting 1, in order that the length in the tire circumferential direction of each piece after cutting and that both of the end surfaces in the circumferential direction of the piece after cutting are included in the cutting regions, the cutting lines of each piece are set at different not less than two positions (a, a? and b, b?) in the tire circumferential direction and the pieces are cut by either one of the set cutting lines.

Abstract: A pneumatic tire exhibiting high traction performance. A center circumferential groove (14) is provided on the equator (CL) of the tread (12), and between shoulder circumferential grooves (18) on both sides of the center circumferential groove (14) are arranged first lateral grooves (20) formed at a smaller angle relative to the axial direction of the tire than the first lateral groove (20). One end of each first lateral groove (20) and one end of each second lateral groove (22) are made to merge at a shoulder circumferential groove (18), and shoulder lateral grooves (23) are arranged on the outer side of each shoulder circumferential groove (18). Each shoulder lateral groove (23) extends from the merging portion toward a tread end (12E) and is formed at a smaller angle relative to the axial direction of the tire than that of the first lateral groove (20). Because the angle of the shoulder lateral grooves (23) relative to the axial direction of the tire is less, traction performance of the tire increases.

Abstract: A pneumatic tire comprises a tread portion provided with a shoulder main groove, shoulder lateral grooves extending from the shoulder main groove toward axially outwardly, the shoulder main groove extending in a zigzag manner comprising linear portions and curved portions which are arranged alternately in a circumferential direction of the tire, each linear portion inclined with respect to the circumferential direction of the tire, each curved portion having a radius of curvature of from 12-80 mm, the curved portion protruding toward axially outwardly of the tire, the shoulder main groove having a pair of groove edges and a circumferential space therebetween which straightly extends along the circumferential direction of the tire without coming into contact with both groove edges and the circumferential space with an axial width of from 0.2 to 0.7 times an axial groove width of the shoulder main groove.

Abstract: A method of designing a tire, wherein a tire designer identifies a target residual aligning torque range for a tire design and creates a computer model of the tire, including a buttress angle. Further, the method includes calculating the residual aligning torque of the modeled tire and comparing the calculated residual aligning torque value to the target residual aligning torque to determine whether the calculated residual aligning torque value is within the target residual aligning torque range. The method produces a final tire design having a target residual aligning torque.

Abstract: The present invention provides a pneumatic tire having: a circumferential groove continuously extending in the tire circumferential direction in a ground contact surface of a tread portion; and a resonator provided in a land portion and constituted of a resonance cell portion opened to a ground contact region at a position distanced from the circumferential groove and a siping portion making the resonance cell portion communicate with the circumferential groove, wherein change in a tread pattern as time lapses can be alleviated without scarifying an effect of reducing pipe resonance sounds. Specifically, an opening width of the siping portion at the ground contact surface of the tread portion is designed to change in the longitudinal direction thereof such that the opening with is relatively narrow on the side of the circumferential groove and relatively wide on the side of the resonance cell portion.

Abstract: Lateral grooves 6 are disposed in a land portion 4 between main grooves 2 at prescribed intervals in a circumferential direction TC of the tire, the lateral grooves 6 extending from the main grooves 6 to a circumferential groove 5. Blocks 7 are defined by the main grooves 2, circumferential groove 5 and lateral grooves 6. At least two sub-grooves 8 are disposed in each block 7 at a prescribed interval in the tire circumferential direction TC, the sub-grooves 8 extending from a main groove 2 adjacent thereto in a width direction of the tire. At least three block portions 7A, 7B and 7C are formed. The width of the main groove 2 adjacent to the block 7 is varied by making the block widths Wa, Wb and Wc of the block portions 7A, 7B and 7C different from each other. A groove wall surface, facing the main groove, of a block portion less in width has a greater inclination angle with respect to a tread normal direction.

Abstract: A pneumatic tire having a tread surface provided with a plurality of circumferential grooves and lateral grooves each having one end opened into that circumferential groove and the other end terminating in a land portion. At least one lateral groove is always included completely in the ground contact surface of the tread. The groove width of the lateral grooves is at least locally not less than 30% of the groove width of the circumferential grooves. Each lateral groove has an extending length not less than 40% of an extending length of the circumferential grooves in the ground contact surface and is provided with a region having a cross-sectional area which increases from its side of opening into the circumferential groove toward its terminal end, and including a starting end with a minimum cross-sectional area that is situated closer to the circumferential groove in which the lateral groove opens.

Abstract: In a tire, a phase difference L1 of transverse grooves 2 is within 25% of the length L of blocks 3, the projected portions 11 are alternately on both sidewalls 10, L2 of the portion 11 is 20% to 45% of L, and in the cross-section of the width direction of the main groove 1, the edge 15 of the portion 11 at the groove bottom is more of a sidewall 10 side than a center line 19 of the groove 1, the outline of the portion 11 is at least on a virtual surface 17 that connects the edge 13 of the groove 1 at the tread surface and the edge 15. The tire also has one or a plurality of sub-projected portions 21, 22 projected from the surface 17.

Abstract: A pneumatic tire is provided which has sufficient total properties and mass productivity of a tire without reducing drainage capability due to narrowed circumferential grooves, achieves high design flexibility of tread patterns and stiffness of land portion as intended, and also effectively reduces undesired air column resonance noise produced by the circumferential grooves. The pneumatic tire includes a circumferential groove 3 which continuously and circumferentially extends in a straight line and arranged on a tread 1, and resonators 5 which are open to the circumferential groove 3 and terminate in a land portion 4, each of the resonators 5 being configured with an air chamber 6 open toward a land portion surface, and a narrowed neck 7 for communication between the air chamber 6 and the circumferential groove 3, and the narrowed neck 7 has the plane maximum width w0 which is within a range of from 3 to 50% of the plane maximum width w1 of the air chamber 6.

Abstract: A method of designing a tire designs a tire comprising a step 20 of determining a resonance sound frequency f being a reference frequency of an air column resonance sound produced by the tire, on the basis of a ground contact length of the tire in a case where a standard internal pressure and a standard load are applied to the tire, a step 30 of determining the number of pitches of the block row, and a step 40 of determining a block row phase in a case where a band of a secondary pitch noise frequency fp2 falls within a range overlapping with a band of the resonance sound frequency f, the block row phase defined by intervals at which the plurality of blocks forming the block row are placed, the secondary pitch noise frequency fp2 being a secondary component of a reference frequency of pitch noise arising from the block row at a reference speed being a reference traveling speed of a vehicle equipped with the tire.

Abstract: Provided is a pneumatic tire which employs pitch variation for suppressing pattern noise and has uniformity further improved. Pitches 3a, 3b and 3c with different pitch lengths are formed so that a pitch with a larger pitch length is set to have a smaller groove area ratio, and to have a larger groove wall angle ? on the obtuse angle side that is formed by a groove wall of a lateral groove 2 and the direction tangential to the thread surface.

Abstract: Provided is a pneumatic tire which employs pitch variation for suppressing pattern noise and has uniformity further improved. Pitches 3a, 3b and 3c with different pitch lengths are formed so that a pitch with a larger pitch length is set to have a smaller groove area ratio, and to have a larger groove wall angle ? on the obtuse angle side that is formed by a groove wall of a lateral groove 2 and the direction tangential to the thread surface.

Abstract: A pneumatic tire with improved steering stability without raising air columnar resonance noise level is provided. The pneumatic tire comprises upper thin grooves 11a extending from a branch point 21 in the depth direction of a main groove on the tread surface side and a plurality of lower thin grooves 11b extending from the branch point 21 in the depth direction of the main groove on the groove bottom side, which are formed at intervals along the tire circumferential direction R in a sidewall of the main groove and a distance B from the groove bottom of the main groove 1 to the branch point 21 is 30 to 60% of the depth D of the main groove 1.

Abstract: A pneumatic tire has longitudinal grooves formed continuously in a circumferential direction of the pneumatic tire in a region of a buttress part disposed between a tread part and a sidewall part; a plurality of transverse grooves formed continuously with the longitudinal grooves in the above-described region of the buttress part in an axial direction of the pneumatic tire, with the transverse grooves spaced at certain intervals in the circumferential direction of the pneumatic tire; and a concave portion formed in each of a plurality of blocks surrounded with the longitudinal grooves and the transverse grooves, with the concave portion extended in the circumferential direction of the pneumatic tire. The above-described region of the buttress part is adjacent to a periphery of an end of a contact surface of the tread part. The number of the concave portions is varied according to a circumferential length of each of the blocks.

Abstract: The present invention provides a pneumatic tire having: a circumferential groove continuously extending in the tire circumferential direction in a ground contact surface of a tread portion; and a resonator provided in a land portion and constituted of a resonance cell portion opened to a ground contact region at a position distanced from the circumferential groove and a siping portion making the resonance cell portion communicate with the circumferential groove, wherein change in a tread pattern as time lapses can be alleviated without scarifying an effect of reducing pipe resonance sounds. Specifically, an opening width of the siping portion at the ground contact surface of the tread portion is designed to change in the longitudinal direction thereof such that the opening with is relatively narrow on the side of the circumferential groove and relatively wide on the side of the resonance cell portion.

Abstract: A vehicle tire includes a tread provided with a tread pattern, which is made up of circumferentially arranged design units having a plurality of pitch lengths Pi (i=l to j) including a minimum pitch length Pl and a maximum pitch length Pj. Each of the design units has at least one groove with side walls each having an inclination angle ?i in a cross section parallel to the tire equator, and the inclination angle ?1 in the design unit having the minimum pitch length P1 is less than the inclination angle ?j in the design unit having the maximum pitch length Pj, whereby the rigidity difference between the design units having different pitch lengths is decreased. Preferably, the angle ?i in a design unit having a pitch length Pi is not more than the angle ?i+1 in a design unit having the next longer pitch length Pi+1.

Abstract: A pneumatic tire has main grooves 1 extending in the tire circumferential direction, plural types of oblong hole groups 21 and 22 in the sidewall 3 of the main groove 1. The oblong hole groups have oblong holes 11 and 12 of the same shapes extending in the groove depth direction of the main groove 1 in the circumferential direction at intervals At least one of the widths w1 and w2, the depths d1 and d2, the spaces p1 and p2 of the oblong holes 11 and 12 differs from those of the other oblong hole groups by 0.1 mm or more, the circumferential lengths r1 and r2 of each oblong hole group is at least 5 mm, the circumferential length of respective oblong hole groups except the longest oblong hole group is not less than 10% of the circumferential length of the longest oblong hole group.

Abstract: A pneumatic tire comprises a tread portion provided with annular regions each provided with axial grooves each extending from one of the axial edges of the annular region, wherein each axial groove is defined as having a groove width of from 2.0 to 6.0 mm and an axial length of not less than 40% of the axial width of the annular region. The annular regions are different from each other with respect to the number Nj of the axial grooves therein, and the greatest common divisor of the different numbers Nj of the grooved annular regions is in a range of from 10 to 40.

Abstract: A pneumatic tire is provided in the tread portion (2) with a circumferential groove (3, 3b, 3c) extending continuously in the tire circumferential direction and having a pair of oppositely opposed groove walls (6). The circumferential groove (3, 3b, 3c) is provided in at least one of the groove walls (6) with radial grooves (9) arranged along the longitudinal direction of the circumferential groove (3). The radially outer end (9o) of the radial groove (9) is positioned in a range (a1) of from 0 to 20% of the depth (GDt) of the circumferential groove. The radially inner end (9i) of the radial groove (9) is positioned in a range (a2) of from 80 to 100% of the depth (GDt) of the circumferential groove. The radial groove has an opening width (g) of not less than 1.0 mm, but not more than 6.0 mm.

Abstract: A method of making a finite element model of a tire is disclosed. The tire is provided in a tread portion with a fine groove having a dead end including at least the bottom. The tread portion is divided into elements so that the elements include first elements on one side of the fine groove and second elements on the other side of the fine groove, and the first elements and second elements have nodes in common at the dead end, but the first elements and second elements do not have nodes in common at other positions than the dead end.

Abstract: Vehicle tire includes a tread having a circumference, profile structures, and grooves. The grooves run at least one of generally diagonally into a central area of the tread and generally diagonally over a central area of the tread. The grooves and the profile structures form base pitches. The base pitches are arranged over the circumference and have a pitch sequence which minimized tire noise. At least two of the base pitches have different circumferential lengths. One of the at least two base pitches includes at least one profile structure. Another of the at least two base pitches includes at least two profile structures separated by at least one cross-groove. 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: A method for determining preselected performance characteristics of a tire tread includes the steps of dividing the tread into a 3-D grid of cells; dividing a tread contact area into longitudinal and transversal strips; associating a longitudinal or transversal stiffness value with each strip using a linear relationship; assigning a preselected deformation state to each longitudinal and transversal strip; determining at least one single force, associated with each strip and acting in the longitudinal or transversal direction by means of the stiffness value and the deformation state; determining at least one total force associated with each contact area by summing all single forces, the total force representing at least one of the performance characteristics; determining a pattern of the total forces of all the contact areas; and analyzing the pattern of total forces to evaluate whether they assume values that optimize at least one preselected performance characteristic of the tread.

Abstract: A mold which is for a pneumatic tire comprising a pair of bead portions, a pair of sidewall portions and a tread portion provided with a tread pattern formed by repeating a pattern unit around the tire at plural kinds of pitches in a sequence, is disclosed. The mold comprises a sidewall molding surface for one of the sidewall portions, and a tread molding surface provided with the negative tread pattern formed by repeating the negative pattern unit at the above-mentioned plural kinds of pitches in order to mold the tread pattern. The sidewall molding surface comprises sector regions defined as extending radially inwardly from the pattern units, respectively, wherein the largest sector regions defined as extending from the pattern units with the largest pitch swells towards a cavity of the mold when compared with the smallest sector regions defined as extending from the pattern units with the smallest pitch. The mount of the swelling is such that the larger the pitch, the larger the amount of swelling.

Abstract: When a single performance or a plurality of antinomical performances are to be achieved, the best mode of a tire is designed under a given constraint condition. Each of blocks included in two pitch groups designated in a pitch array is modeled (100), an objective function representing a tire performance evaluation physical amount, a constraint condition for restricting a tire shape, and a design variable which is an angle of a wall surface determining each of block shapes are determined (102). Next, the design variable is varied continuously by &Dgr;ri to determine a modified model (104 to 108). A value of the objective function of the modified model and a value of the constraint condition are calculated, and a sensitivity of the objective function and a sensitivity of the constraint condition are determined (110, 112).

Abstract: The present invention provides a tire with a sacrificial rib 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 to form a main tread width for contacting the supporting surface. A sacrificial rib is provided for contacting the supporting surface at each lateral side of the main ribs. The sacrificial rib is separated from the main ribs by a narrow shoulder groove having a groove width not greater than about 1.5 millimeter. The sacrificial rib has a surface width in the range of about 2.5 percent to about 12 percent of said tread width. The sacrificial rib has a recess defined by a radial offset from a transverse or lateral profile of the main ribs. The offset has a value in the range of about 0.50 millimeter to about 2.0 millimeters when the tire is new.

Abstract: A tire includes, among the conventional tread pattern elements, at least one measuring element having a central zone and an encircling zone. In normal operation, the central zone 10 of a measuring element slides over the ground while, conversely, the tread as a whole does not slide over the ground. Measurements are carried out of the maximum adherence potential with the ground, at any moment, due to the central zone of a measuring element. In an alternative embodiment, the measuring element may comprise a circumferentially extending rib(s) or tread block(s) whose ground contact surface(s) is spaced at a lesser radial distance from the wheel axle than the spacing of the ground contact surfaces of the conventional tread blocks.

Abstract: A pneumatic tire having improved snow traction and tread wear, and improved noise and handling properties, has 80 to 105 pitches and a sipe density of 1.0 to 1.1. The tire has a substantially square footprint, and has a footprint shape factor (FSF) of 1.0 to 1.25. The tire has an open central and intermediate region, as compared to the shoulder region, and has lateral groove depths that vary from 50% to 100% of the tread depth, wherein the shallower grooves are disposed toward the central and intermediate regions of the tire.

Abstract: A pneumatic tire having improved snow traction and treadwear, and improved noise and handling properties, has 80 to 105 pitches and a sipe density of 1.0 to 1.1. The tire has a square footprint, and has a footprint shape factor (FSF) of 1.0 to 1.25. The tire has an open central and intermediate region, as compared to the shoulder region, and has lateral groove depths that vary from 50% to 100% of the tread depth; wherein the shallower grooves are disposed toward the central and intermediate regions of the tire.

Abstract: A pneumatic tire has a block pattern of a tread defined by a plurality of circumferential grooves extending in a circumferential direction of the tread and a plurality of lateral grooves each extending across the circumferential grooves and tread ends, wherein specified chamfered face, sipe or fine groove is formed in each block of all block rows to improve a self-aligning torque in the high-speed running of a vehicle.

Abstract: A pneumatic tire having improved snow traction and tread wear, and improved noise and handling properties, has 80 to 105 pitches and a sipe density of 1.0 to 1.1. The tire has a substantially rounded footprint, and has a footprint shape factor (FSF) of 1.2 to 1.5. The tire has an open central and intermediate region, as compared to the shoulder region, and has lateral groove depths that vary from 50% to 100% of the tread depth, wherein the shallower grooves are disposed toward the central and intermediate regions of the tire.

Abstract: A pneumatic tire having an improved tread pattern which is capable of improving the steering stability, tire uniformity and the like without increasing a tread pattern noise is disclosed. The tire comprises rows of circumferentially arranged tread elements such as blocks, the tread elements in each row having plural kinds of different circumferential widths. The circumferential widths of the axial grooves and the circumferential lengths of the tread elements in each row satisfy 1.2≦GR/BR≦1.5 where BR is the length maximum ratio defined by the ratio (Bll/Bss) of the maximum circumferential length (Bll) to the minimum circumferential length (Bss), and GR is the width maximum ratio defined by the ratio (Gll/Gss) of the maximum circumferential width (Gll) to the minimum circumferential width (Gss).

Abstract: A pneumatic tire comprising a tread portion provided with oblique grooves to define narrow and circumferentially long blocks therebetween, the oblique grooves inclined at angles &thgr; of not more than 60 degrees with respect to the circumferential direction of the tire, each of the long and narrow blocks provided with at least tow sipes each extending across the block from one of the adjacent oblique grooves to the other, while inclining reversely to the oblique grooves, to subdivide the block into at least three block pieces.

Abstract: A tread for a vehicle tire includes at least one circumferentially extending longitudinal groove and transverse grooves emanating from the longitudinal groove for defining blocks in a pattern and sipes arranged in the tread. Each sipe defines a sipe depth extending from a pattern face of the tread toward a pattern base of the tread. At least one of the sipes is located in at least one of the blocks and is configured to have legs defining a V-shape. An intersection of the legs is arranged in a side surface area of the block facing the longitudinal groove. Ends of the legs are oriented away from the side surface area.

Abstract: A pneumatic radial tire comprises a radial carcass, a belt, and a row of many blocks having different lengths along a circumference of a ground contact region under pitch variation defined in a tread rubber of the tread portion by at least two straight main grooves and a plurality of lateral sub-grooves extending between the mutual main grooves at an inclination angle of less than 90° with respect to the circumference of the ground contact region, in which the block row satisfies such relationships that an inclination angle &phgr;L of an edge of a long-pitch block is larger than that &phgr;S of an edge of a short-pitch block and an inclination angle &agr;L of each block wall face of a long-pitch block is larger than that &agr;S of each block wall face of a short-pitch block, or further an inclination angle &bgr;S of a block wall face of a short-pitch block is larger than that &bgr;L of a block wall face of a long-pitch block.

Abstract: A tire for a wheel of a vehicle comprises a toroidal carcass provided with axially opposite sidewalls and beads for anchoring the tire to a rim of the wheel, a tread band located crownwise on the carcass, comprising a surface with a plurality of hollows and grooves defining a raised tread pattern, and a belt structure interposed between the carcass and the tread band, axially extending between the sidewalls. The tread band comprises at least first and second circumferential axially-contiguous portions arranged to contact a road surface. The first portion is formed of a first composition comprising a reinforcing filler having at least 40%-by-weight carbon black and at least some white filler, the second portion is formed of a second composition comprising a reinforcing filler having at least 20%-by-weight white filler, and the first composition is different from the second composition.

Abstract: In a pneumatic tire comprising a tread portion divided into a central region and both side regions, at least one rib-shaped main land part is formed in the central region and a plurality of main slant grooves are arranged so as to extend obliquely from the central region toward each tread end of the tread portion with respect to the equatorial plane to form first slant land parts among these main slant grooves, in which the first slant land part has a plane form of approximately a triangle, and a first auxiliary land part is arranged between the rib-shaped main land part and the main slant groove.