Abstract: Tire tread including a pattern formed by at two ridges of mean width L, which include a plurality of incisions whose traces on the contact surface extend between two points of intersection A and B, the segment AB making an angle with the transverse direction of the tread at most equal to 40°, the tread wherein each incision, of mean width E, includes a succession of incision portions, some of said incision portions having, on any surface parallel to the contact surface in the new condition and located between said surface in the new condition and ? of the maximum depth of the incision, traces that make an average angle ? at most equal to 15° with the longitudinal direction of the tread, said portions having a total length Lt which is at least equal to one-fifth of the ridge width; and in that the incision portions whose traces make an average angle ? are provided on their opposite walls with relief elements of amplitude K designed to cooperate with one another to block relative movements between one incision

Abstract: A pneumatic tire tread has tread elements formed by circumferential and/or lateral grooves. At least one tread element has a sipe that devolves from a constant width sipe having a three dimensional aspect in at least a portion of the radially outer portion of the sipe to a wider width groove at the base of the tread feature.

Abstract: A pneumatic tire according to the present invention includes blocks on its tread which are segmented by plural circumferential grooves 3 extending along a tire circumferential direction and plural lateral grooves 5 extending along a tread width direction. Circumferential sipes extending along the tire circumferential direction are provided in the blocks. Inside circumferential sipes extend straight along a tire radial direction and outside circumferential sipes extend along the tire radial direction in zigzag patterns. According to the present invention, a handling performance, especially, a cornering performance can be improved regardless of road surface conditions.

Abstract: A tire is configured having first and second shoulder rows of shoulder tread elements opposite respective first and second interior rows of interior tread elements, separated respectively by circumferentially extending, zig-zag shaped first and second grooves within a tire tread region. Each groove is defined by opposed shoulder tread elements and interior tread elements and includes a circumferentially continuous see-through central groove portion extending parallel to a circumferential centerplane of the tread. The see-through circumferential grooves communicate with angular intermediate and shoulder lateral grooves having a relatively wide mouth dimension adjacent to a respective circumferential grooves. Staggered in and out shoulder regions within the shoulder tread elements facilitate gripping edges and prevent mud clogging of the shoulder grooves.

Abstract: A pneumatic tire has a tread pattern having shoulder blocks arranged in a tire circumferential direction in a shoulder portion of a tread surface, and slits to sectionalize the shoulder blocks. Slit wall surfaces in a trailing side and a leading side of the shoulder blocks are inclined to the slit side from both end portions in a width direction of the shoulder block toward a center portion in the width direction. A notch portion is provided in the center portion in the width direction in the slit wall surface in the trailing side or the leading side of the shoulder block.

Abstract: The tread of a tire designed particularly to run on snowy, icy or wet surfaces. The tread comprises elements in relief (e.g., blocks or ribs), each having a running face and lateral faces. At least one element in relief is provided with an incision defined along a mean plane. The tread comprises at least two holes passing through the element in relief substantially parallel to the mean plane of the incision. Each hole opens onto two lateral faces of the element in relief, and the holes are situated on one and the same side of the mean plane of the incision in spaced relationship to the incision.

Abstract: Disclosed is a pneumatic tire which is allowed to increase block stiffness not only during braking and driving but also during cornering, and is allowed thereby to compatibly enhance tire performances both during braking and driving and during cornering.

Abstract: Provided is a pneumatic tire having a tread surface in which two circumferential direction main grooves continuous in a tire circumferential direction are arranged on left and right sides of a tire center, and land portions are defined by the circumferential direction main grooves as ribs or blocks having lug grooves. Multiple fine grooves are provided in each of right and left walls of the circumferential direction main groove, the fine grooves being inclined to the tire circumferential direction and provided in regions along the circumferential direction main groove, covering at least 50% of the entire circumference thereof in total. In each of the two circumferential direction main grooves on corresponding tire shoulder sides, the fine grooves in the right and left walls are inclined to the tire circumferential direction in the same direction in a plan view in a tire radial direction.

Abstract: A pneumatic tire has a tread pattern which comprises at least three circumferential grooves with a groove width of 6 to 18 mm and a groove depth of 6.0 to 16.0 mm extending in a tire circumferential direction, wherein, on groove walls on both sides forming the at least three circumferential grooves, first inclined walls inclined by an inclination angle of 5 to 20 degrees with respect to the tire circumferential direction and second inclined walls inclined by an inclination angle of 0 to 45 degrees with respect to a tire width direction are provided so as to be successively connected in the tire circumferential direction so that positions of groove ends in the tire width direction vary in the tire circumferential direction.

Abstract: A pneumatic tire having shoulder blocks defined on a shoulder side of the tread surface by lateral grooves extending in the widthwise direction of the tire beyond a ground contact end of the tire, the shoulder blocks being arranged in the circumferential direction of the tire. A bottom-raising portion is provided only on a bottom of every other lateral groove of the lateral grooves. Two shoulder blocks adjacent in the circumferential direction of the tire are connected by the first bottom-raising portion.

Abstract: A pneumatic tire having a rotation direction specified in one direction. The tread surface has a main groove extending on the equatorial plane of the tire, right and left first inclination grooves extending in an inclined manner from the main groove toward the reverse rotation direction of the tire, and right and left second inclination grooves disposed on the opposite sides of the main groove. The right and left second inclination grooves are disposed at symmetrical positions with respect to the equatorial plane of the tire. Blocks are formed on the opposite sides of the main groove by the main groove, right and left first inclination grooves and right and left second inclination grooves.

Abstract: A tire has a tread with a plurality of ground engaging tread elements. In at least one of the tread elements is a sipe having a depth in the radial direction of the tire. The sipe has a crossed configuration comprised of two sipes. At least one of the sipes of the crossed sipe has a radially outer portion having three dimensional elements and a radially innermost portion have a substantially linear configuration. A blade useful for manufacturing the sipe has a crossed blade configuration with a configuration corresponding to the formed sipe.

Abstract: A tread provided with a plurality of cutouts of essentially transverse orientation and characterized in that when new, some of the transverse cutouts form on the running surface hollowed zones of average width Lt greater than or equal to 2 mm and of maximum depth Pt at most equal to 80% of the thickness Pb of tread to become worn, the other transverse cutouts forming on the same running surface incisions of average width Li less than 2 mm and of depth Pi at most equal to Pt. A plurality of the incisions extending by hollowed zones such that after homogenous wear of the tread the volume V1 of the hollowed zones opening on to the new running surface is between 50% and 150% of the volume V0 formed by the hollowed zones when new.

Abstract: A pneumatic tire according to the present invention improves wet performance. The pneumatic tire has a tread surface 1. A first main groove 2 extending in the circumferential direction TC of the tire is provided in the tread surface 1. First lateral grooves 7 extending from the first main groove 2 outward in the widthwise direction of the tire beyond one ground contact end TX1 of the tire are disposed at prescribed intervals in the circumferential direction TC of the tire. Blocks 8 are defined by the first main groove 2 and the first lateral grooves 7. The first lateral grooves 7 comprise inner groove portions 7A and outer groove portions 7B. The inner groove portions 7A extend with their widths gradually increasing from the first main groove 2 outward in the widthwise direction of the tire to midways of the first lateral grooves 7.

Abstract: A pneumatic tire comprises a tread portion provided with sipes, the sipes each having a zigzag configuration at any depth from the top of the sipe to a certain depth, and the zigzag configuration having vertexes Q1 on one side of the zigzag and vertexes Q2 on the other side of the zigzag, wherein as the depth increases from the top of the sipe to said certain depth, the vertexes Q1 shift in the longitudinal direction of the sipe and the direction of the shift is turned at least once such that the vertexes Q1 first shift towards one direction then towards the other direction, thereby describing a zigzag line extending from the top of the sipe to said certain depth and having at least one tuning point, but the vertexes Q2 describe lines which are linear or less zigzag when compared with the zigzag lines described by the vertexes Q1.

Abstract: In a pneumatic tire, a rotating direction of the tire is specified. A plurality of sipes are formed in land parts. Each of the sipes has a substantially zigzag shape formed by a string of multiple V-shaped parts in a plan view of a tread part, so that a falling amount of the land parts in the rotating direction of the tire differs from that of the land parts in a reverse direction, against an outside force generated when the tire lands on the ground. Besides, a direction of the V-shaped part of the sipe is set so that the falling amount of the land parts in the rotating direction of the tire is smaller than that in the reverse direction.

Abstract: A pneumatic tire which includes a tie bar in a lateral groove disposed in a block array, the tie bar connecting adjacent blocks in a circumferential direction through the lateral groove. The tie bar is formed with a sipeing having a zigzag portion, the zigzag portion extending in a zigzag manner in a direction of a groove centerline of the lateral groove. The sipeing is a three-dimensional sipeing in which a sipeing wall surface is repeatedly recessed and projected, three-dimensionally.

Abstract: A pneumatic tire comprising a tread portion having tread elements each provided with a sipe, wherein the sipe is open to a upper surface of the tread element, and has an open top end including a zigzag part and a bottom, wherein the sipe comprises: a first portion in which the zigzag part of the open top end extends to a side of the bottom in a state of being inclined to one side of a longitudinal direction of the sipe; a second portion connected to an inner side in a radial direction of the first portion, and in which the zigzag part extends to the side of the bottom in a state of being inclined in an opposite direction to the first portion; and a third portion connected to an inner side in a radial direction of the second portion, and in which the zigzag part extends to the side of the bottom in a state of being inclined in an opposite direction to the second portion, and the sipe satisfies the following relation (1): ?1>?2>?3??(1) where ?1 is a ratio (a1/h1) between a displacement length a1 of the

Abstract: Both a mold blade for forming sipes and the sipe so formed in a tire tread element have three-dimensional portions. In the formed sipe, the three-dimensional portion creates a constant interlocking of the opposing sipe faces. The blade and the sipe have two radially adjacent rows of projections, wherein the projections are separated by a planar section, the planar section having a defined length and width.

Abstract: A pneumatic radial tire having a thin groove continuous in a tire circumferential direction at a buttress formed between a shoulder of a tread and a sidewall includes a tire contour portion that is formed between an end portion of the shoulder and a groove floor of the thin groove. A tire transverse direction outermost portion at a shoulder side curved portion is disposed further toward a tire radial direction inner side than a sidewall side end portion of a sidewall side groove wall surface of the thin groove.

Abstract: A studless tire capable of exhibiting excellent performances on both icy road and snow-covered road, including tread portion 2 having a pair of middle circumferential grooves 3b each extending in a region between 15% and 25% of tread width TW from tire equator C to provide crown region CR between the middle grooves 3b and a pair of shoulder regions Sh between the middle groove 3b and ground contact edge E, wherein the crown region CR includes rows R1, R2 of blocks B having sipes S and defined by zigzag inner circumferential grooves 3a and crown lateral grooves 4a, 4b, each shoulder region Sh includes rows R3, R4 of blocks B having sipes S and defined by linear outer circumferential grooves 3c and shoulder lateral grooves 4c, 4d, and groove area rate Gs (%) of shoulder regions Sh is larger than groove area rate Gc (%) of crown region CR so that the difference (Gs?Gc) is from 3 to 7%.

Abstract: The invention provides a pneumatic tire which can obtain a sufficient engagement force in a depth direction in comparison with a known pattern while making good use of an advantage of a waveform sipe, and is hard to be affected in an inhibiting effect in accordance with a collapsing direction of a block. In a pneumatic tire provided with a tread pattern having a plurality of blocks forming a plurality of sipes therein, the sipe is formed in a zigzag or wavy line shape on a surface of the block and formed as a waveform groove in a depth direction, and the waveform groove has an auxiliary wavy portion in a wavy surface direction, and has a concave portion in a peak portion of the wave.

Abstract: A tread (1) for steer axle tires for a heavy vehicle, the tire having a preferred direction of travel, the tread comprising grooves (2) of generally circumferential orientation defining at least three ribs (30, 31, 32, 33, 34), two of the ribs forming the edges (30, 34) of the tread, some of the intermediate ribs (31, 32, 33) being provided with a plurality of incisions (41, 42, 43), of general transverse orientation and substantially parallel to each other, the incisions having an average inclination other than zero relative to the direction perpendicular to the running surface of a new tread, this tread being characterised in that, when viewed in a section plane perpendicular to the axis of rotation of the tyre, the incisions in the intermediate ribs form, on and in the vicinity of the running surface when new of the tread, an angle close to or equal to 0° with a line perpendicular to said surface at the point of intersection, whereas the angle of each of these incisions increases in the depth of the tread.

Abstract: A pneumatic tire comprising a tread portion 2 having blocks 7 each provided with sipeings 10, wherein each sipeing 10 has an opening having a zigzag portion 11 in its opening edge shape J at a block surface S, and opposing wall surfaces in the depth direction Ff which have zigzag displacement portions which are displaced toward one end of the longitudinal direction Fn of the opening and the other end and which are alternately repeated while substantially maintaining the opening edge shape J in the depth direction, and wherein each sipeing 10 satisfies the following equations, W1?W2 ??(1) and 0.7×W2?W3>0, ??(2) in which W1, W3 and W2 are displacement amounts of a zigzag displacement portion 15U located on the block surface side, a zigzag displacement portion 15L located on the sipeing bottom side and an intermediate zigzag displacement portion 15M in a direction Fv perpendicular to the longitudinal direction Fn, respectively.

Abstract: There is provided a tire vulcanizing mold capable of smoothly and surely forming narrow-width grooves in a treading face without causing the damage, breakage and the like of projections for the formation of the grooves in a sector mold and land portions in the tread, which comprises a plurality of sector molds arranged at predetermined pitches in a circumferential direction and displacing in synchronization with each other in extension and retraction directions to conduct the vulcanization of a tire tread portion, wherein a projection for the formation of the groove formed in an inner surface of each of the sector molds is projected from the inner surface of the sector mold in a direction substantially parallel to a displacing direction of the respective sector mold.

Abstract: It is a subject to suitably decrease the rigidity of blocks, to generate suitable collapsing of the blocks, to sufficiently exhibit edge effects of sipes, and to improve braking performances and the like in the medium term of wear and thereafter; and for solving this subject, in a pneumatic tire formed with blocks on its tread and engraved with sipes 11 on the blocks, the sipes 11 are classified into a surface portion 12, an intermediate portion 13, and a bottom portion 14 in a depth direction from a tread surface 17 up to sipes bottom 18, wherein the surface portion 12 and the bottom portion 14 open in a wave-shaped form in which crest portions 21 and trough portions 22 of the wave-shaped form extend in directions vertical to the tread, while the intermediate portion 13 opens in a wave-shaped manner in which the crest portions 21 and trough portions 22 of the wave-shaped form extend in a zigzag-like manner.

Abstract: It is an object of the present invention to improve the running performance on snowy and icy roads, and for this purpose, blocks provided with sipes are formed at a tread portion. The sipes include an open top end that opens at a block surface and a bottom, and a configuration of the sipes in a plane parallel with the block surface comprises a zigzag part extending in the length direction of the sipes. The zigzag part displaces upon turning back to one side and to the other side in a length direction of the sipes in the course from the open top end to the bottom. At least one block includes a first sipe and a second sipe which depths of the turn-back points of displacement from the open top end and/or positions of the turn-back points of displacement in the length direction differ from each other.

Abstract: A pneumatic tire including sipes that have at least one ends positioned within blocks. The sipes are arranged such that each of the sipes meanders from the one end to the other end thereof to form a meandrous shape, and as the depth of the sipes increases, the meander width of the sipes gradually increases from their openings to at least the 80%-worn position of the blocks. The sipes each have a sipe length L, which is defined as a center line length between an intersection of a center line passing the center of the meander width of the meandrous shape with a first straight line and an intersection of the center line with a second straight line, the first straight line being orthogonally drawn to the center line from the one end of the sipe and the second straight line being orthogonally drawn to the center line from the other end of the sipe at the same depth position of the sipe, the sipe length L gradually decreasing as the sipe depth increases.

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 tire for a motorcycle wherein the radius of curvature (R1) of a corner portion on one side (an inside in an axial direction) of a groove of the tire is smaller than a radius of curvature (R2) of the other corner portion; the radii of curvature (R1) and (R2) are set to be 2 mm or more; a first phantom circle for defining the corner portion is inscribed on a second phantom circle for defining the corner portion; the point of contact of the first phantom circle and the second phantom circle is positioned on the outside from the center of a groove; and the distance between the center of the groove and the point of contact is equal to or smaller than one fifth of the width (B) of the groove.

Abstract: Tire tread including a pattern formed by at two ridges of mean width L, which include a plurality of incisions whose traces on the contact surface extend between two points of intersection A and B, the segment AB making an angle with the transverse direction of the tread at most equal to 40°, the tread wherein each incision, of mean width E, includes a succession of incision portions, some of said incision portions having, on any surface parallel to the contact surface in the new condition and located between said surface in the new condition and ? of the maximum depth of the incision, traces that make an average angle ? at most equal to 15° with the longitudinal direction of the tread, said portions having a total length Lt which is at least equal to one-fifth of the ridge width; and in that the incision portions whose traces make an average angle ? are provided on their opposite walls with relief elements of amplitude K designed to cooperate with one another to block relative movements between one incision

Abstract: A tire includes a plurality of tread blocks disposed circumferentially around the tire. At least one sipe is formed into at least one of the tread blocks and is defined by first and second confronting sidewalls. The sipe has a cross-sectional profile in a plane generally perpendicular to the top surface of the tread block, which profile has a generally arcuate central portion and first and second ends separated by the central portion. The sidewalls are spaced apart at least one first width at the central portion of the sipe, and are spaced apart at least one second width at the ends, wherein the second width is greater than the first width. In one embodiment, the sipe has a cross-sectional profile having a stepped configuration.

Abstract: A heavy-duty pneumatic tire designed to suppress the occurrence of heel-and-toe wear in the shoulder blocks while maintaining good drainage and traction performance through the final stage of the wear life. In this heavy-duty pneumatic tire, whose shoulder portion is divided into a plurality of shoulder blocks in the tire circumferential direction, and wherein the depth of the lug groove between each two adjacent of the shoulder blocks is set to be equal to the depth of main the grooves, a non-contact rib is provided, in a serial configuration in the tire circumferential direction, to a buttress portion outside a ground contact width, so as to come into contact with the side faces of the shoulder blocks in the state that the tire is in contact with the ground with a specified inflation pressure and a specified load.

Abstract: Both a mold blade for forming sipes and the sipe so formed in a tire tread element have three dimensional portions. In the formed sipe, the three dimensional portion creates a constant interlocking of the opposing sipe faces. The blade and the sipe have at least one row of alternating polygonal shaped recesses and protrusions. The recesses and protrusions terminate in a vertex; the vertex has a planar, or two-dimensional, configuration that is parallel to either-the blade centerline or the sipe centerline.

Abstract: A method for changing the residual aligning torque (RAT) of a pneumatic tire by forming angled sipes in certain of the tread blocks in at least a pair of circumferentially extending ribs, each rib being located on an opposite side of the mid-circumferential plane of the tire. The sipes in the tread blocks in one of the ribs are formed at an inclined angle opposite to the inclined angle of the sipes in the tread blocks in the opposite rib. The RAT can also be changed by varying the depth and width of the opposed angled sipes.

Abstract: Disclosed is a pneumatic tire provided with multiple blocks 6 on a tread 1. A sipe 7 provided on the block 6 is formed by shifting pitches of a zigzag shape 7a on a tread face 1a side of the sipe and a zigzag shape 7b on a bottom side thereof in the width direction of the tire, and by connecting concave and convex flexion points a, a?, b and b? on the both of the zigzag shapes with edge lines x1, x2 and x3. The block 6 is sectioned by the sipe 7 into a concavo-convex face A in which convex triangular pyramids Aa and convex reverse triangular pyramids Ab are alternately arranged, and a concavo-convex face B in which concave triangular pyramids Ba and concave reverse triangular pyramids Bb are alternately arranged. The concavo-convex faces A sectioned by the sipes are at least disposed in both outermost positions in the circumferential direction of the block in a manner that the concavo-convex faces A are oriented outward from the block.

Abstract: A tread (1) provided with a plurality of cutouts (5, 6, 71, 72, 73, 81, 82, 83) of essentially transverse orientation and characterized in that: when new, some of the transverse cutouts (5, 6) form on the running surface hollowed zones of average width Lt greater than or equal to 2 mm and of maximum depth Pt at most equal to 80% of the thickness Pb of tread to become worn, the other transverse cutouts (71, 72, 73, 81, 82, 83) forming on the same running surface incisions (71?, 72?, 73?, 81?, 82?, 83?) of average width Li less than 2 mm and of depth Pi at most equal to Pt; a plurality of the incisions (71?, 72?, 73?, 81?, 82?, 83?) extending by hollowed zones (71?, 72?, 73?, 81?, 82?, 83?) such that after homogenous wear of the tread the volume V1 of the hollowed zones (71?, 72?, 73?, 81?, 82?, 83?) opening on to the new running surface is between 50% and 150% of the volume V0 formed by the hollowed zones when new. A molding element comprising thick parts and thin parts.

Abstract: A pneumatic tire comprises a tread portion comprising tread elements each provided with a sipe, the sipe having an open top end and a bottom, and in a range from the open top to a certain depth, a configuration of the sipe in a plane parallel with the tread face comprising a zigzag part oscillating in the longitudinal direction of the sipe in the course from the open top to said certain depth.

Abstract: A tire tread comprising grooves defining motifs in relief, at least one of these motifs being provided with first and second incisions, said incisions each being defined by two main lateral surfaces connected by an end surface, each of the first incisions opening on to the running surface of the tread when new and extending at most as far as the depth, and each of the second incisions extends at least as far as the depth. The tread is characterized in that the bottom surfaces of the first incisions and the apex surfaces of the second incisions are functionally arranged such that, whatever the level of wear the length of the ridges on the running surface is at least equal to 75% of the length of the ridges when new.

Abstract: A tread (1) for a tire with a preferred rolling direction, the tread having grooves (2) of substantially circumferential orientation which delimit ribs (30, 31, 32, 33, 35), at least one of which is provided close to each of its traverse edges with a plurality of incisions of width smaller than 1.5 mm. The incisions open onto the contact surface of the tread, are essentially parallel to one another, and having a mean inclination ? different from zero relative to the direction perpendicular to the rolling surface (S) of the tread.

Abstract: Tire tread including a pattern formed by at two ridges of mean width L, which include a plurality of incisions whose traces on the contact surface extend between two points of intersection A and B, the segment AB making an angle with the transverse direction of the tread at most equal to 40°, the tread wherein each incision, of mean width E, includes a succession of incision portions, some of said incision portions having, on any surface parallel to the contact surface in the new condition and located between said surface in the new condition and ⅔ of the maximum depth of the incision, traces that make an average angle &bgr; at most equal to 15° with the longitudinal direction of the tread, said portions having a total length Lt which is at least equal to one-fifth of the ridge width; and in that the incision portions whose traces make an average angle &bgr; are provided on their opposite walls with relief elements of amplitude K designed to cooperate with one another to block relative movement

Abstract: Disclosed is a pneumatic tire effectively controlling uneven wear occurring in the vicinity of a main groove even if a groove width of the main groove is narrowed due to change in tread radius during inflation. In the pneumatic tire, with regard to the main groove having its groove width narrowed during inflation among a plurality of main grooves provided on a tread surface, both groove walls are inclined so that the groove width becomes wider toward the groove bottom, and a protrusion dividing the groove space in the tire width direction is provided at the groove bottom.

Abstract: A pneumatic tire. In a block 18 formed on a tread surface, a sipe 24 which is twisted at a predetermined angle from a surface portion 28 toward a bottom portion 30 is provided. Due to ground contact pressure exerted on a contact patch area 26, small blocks 18a to 18d rotate, so that adjacent small blocks abut each other with a strong force. As a result, leaning of the small blocks 18a to 18d is suppressed, and a contact patch area area on the contact patch area 26 increases, so that performance on ice and snow improves. Moreover, due to rotation of the small blocks 18a to 18d, a torque (SAT) for restoring the small block to an original shape is generated, so that SAT generated by steel cords can be suppressed.

Abstract: In a pneumatic tire including sipes extending in zigzag provided on tread surfaces, both wall surfaces of each sipe, which face to each other, are inclined with respect to a diameter direction of the tire, constituted of triangular wall surfaces, each having two sides expanding toward a sipe bottom with a bending point of a zigzag of the sipe as an apex and of inverse triangular wall surfaces, each having two sides narrowed toward the sipe bottom with one side of the zigzag of the sipe as a base, and a pair of the triangular wall surfaces adjacent to each other and a pair of the inverse triangular wall surfaces adjacent to each other are alternately arranged. Thus, provided is a pneumatic tire capable of improving ice performance without lowering driving stability on a dry road surface, and of suppressing occurrence of uneven wear.

Abstract: A heavy load pneumatic radial tire has the circular fine groove 5 running in the tire circumferential direction at least at one side of the shoulder portion 4 running on both sides of the tread surface 11 of the tread portion 1. The said fine groove 5 has a narrowed area with the central axis 5C of the sectional view of the groove sloping inward in the tire diameter direction from the aperture 51 to the internal part in the tire width direction and an expanded area following thereafter whose groove width expands with a curvature, and the external wall 52 of the said narrowed area slopes outward in the tire diameter direction than the central axis 5C of the said sectional view of the groove and the internal wall 53 of the said fine groove 5 is provided with the convex part 57.

Abstract: A tread for a tire bearing heavy loads, the tread being made of a rubber mix and having at least one incision defined by opposing walls, each wall having elements in relief intended to cooperate with the elements in relief of the facing wall in the contact of the tread with the roadway. The width of the incision is at a maximum in that region of the tread which undergoes the maximum deformations due to the Poisson effect resulting from the loading of the tread in the contact with the roadway, in order to obtain more effective cooperation of the walls defining said incision in the contact.

Abstract: A pneumatic tire in which a block formed in a tread surface has, in a ground contacting surface thereof, a closed sipe which is formed so as to not open onto a groove. The sipe has a first opening formed in the ground-contacting surface of the block, a second opening formed at side surfaces of the block, and a hole which communicates the first opening and the second opening. In accordance with this structure, water taken-in into the sipe from the first opening at the ground-contacting surface of the block is discharged to the second opening contacting at the side surface facing to the groove. As a result, water drainability of the sipe is improved without lowering rigidity of the block. Thus, a ground contacting performance of the block improves. The pneumatic tire therefore has improved performance on wet roads and improved performance on snowy and icy roads without the rigidity of blocks decreasing.

Abstract: A vehicle tire is provided in the tread portion with sipes capable of improving the rigidity of tread rubber, wherein each of the sipes comprises an radially outer part and radially inner parts, the radially outer part extends radially inwards from the tread face to a certain depth H and extends continuously in the longitudinal direction thereof, the radially inner parts extend radially inwards from the radially inner end of the radially outer part, the radially inner parts comprises at least one first inner part inclined towards one side of the radially outer part and at least two second inner parts inclined towards the other side of the radially outer part, and the first and second inner parts alternate with each other in the longitudinal direction of the sipe.

Abstract: Tread profile of a snow tire for a vehicle in which at least two vehicle wheels are rotatably mountable outside of a longitudinal vehicle axis. The tread profile includes a plurality of profile block rows aligned in a circumferential direction and distributed in an axial direction from a first tire shoulder adapted to be positioned toward an outside of the vehicle in an operational state of the tire on the vehicle to a second tire shoulder adapted to be positioned toward an inside of the vehicle in an operational state of the tire on the vehicle.

Abstract: A tire tread having grooves of transverse general orientation defining a plurality of blocks arranged so as to form a tread pattern having a preferred direction of travel, the blocks having a contact face, two lateral faces, a leading face forming an angle a greater than 90° with the contact face and a trailing face. For at least one tread pattern block, the trailing face of the block is formed of an upper part extending from the running face of the block which is extended towards the inside of the tread by a lower part. Furthermore, the upper part of the trailing face is undercut and forms an angle &bgr; of less than 90° with the contact face, whereas the lower part, which is inclined so as to form an angle &dgr; greater than 90° with the contact face, is provided with at least one recess which extends into the interior of the block.