"The penalty kicks, the final goals in the Olympics, playing in front of the president, in front of 90,000 people ... that is what I was born to do ... and my brain is what I used to get myself there."

If you don't feel right after a concussion, talk to your parents, your coach, your doctor ... get a second, third, fourth opinion ... Do not accept that you will not get better.

Bilateral occipital nerve release surgery was the first, significant step to relieving Scurry's debilitating post-concussive headaches.

One out of two girls will sustain a concussion playing soccer, but most will recover and return to play with ease. Nevertheless, awareness and education are key to keeping players safe.

"The Briana Scurry who could tune out 90,000 people during the World Cup and focus on a single ball and know I could keep it out of the goal ... that is who I want to be again."

Retired soccer star Briana Scurry talks about how all her successes started with her mind and her ability to overcome obstacles. After her injury, she felt lost, broken.

Was her depression physiological from the hit to her head or because her professional soccer career was over?

After several weeks of not playing because of a concussion and then failing  several baseline tests, Briana Scurry became very worried.

As someone who had a phenomenal career in professional soccer and that had a career-ending head injury, Briana Scurry knows she can help other female — and male — athletes.

Plasticizing system which can be used in particular for the plasticizing of a tire diene elastomer composition containing, in combination: a plasticizing hydrocarbon resin, the glass transition temperature of which is greater than 0° C.; anda tri- or pyromellitate ester corresponding to the formula (I): in which the R radicals, which are identical or different, represent a hydrocarbon radical and the R' radical represents hydrogen or COOR group. Also, a rubber composition incorporating the plasticizing system and the use of such a composition for the manufacture of a tire or tire semi-finished product made of rubber, in particular of a tire tread, exhibiting an improved wear resistance without having a detrimental affect on its wet grip.

A rubber composition that can be used in applications such as automotive tires and can improve the fuel efficiency performance and driving stability of automobiles and the like, a method for producing a rubber composition, and a tire using the same are provided. A rubber composition comprising: (A) a conjugated diene rubber which is obtained by polymerizing a conjugated diene compound or polymerizing a conjugated diene compound and an aromatic vinyl compound and has a group having an active hydrogen and a group capable of chemically binding to a silica, (B) a silica, (C) a silane coupling agent (I) capable of reacting with a carbon-carbon double bond of the conjugated diene in the conjugated diene rubber, and (D) a silane coupling agent (II) capable of reacting with the group having an active hydrogen; a method for producing a rubber composition, which comprises mixing the above-mentioned composition; and a tire which is obtained by crosslinking and molding the rubber composition obtained by the method for production.

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, and abrasion resistance in a balanced manner, and a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component, silica, and a silane coupling agent, wherein the rubber component contains, based on 100% by mass of the rubber component, not less than 5% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a constituent unit represented by formula (I) below, at least one terminal of the polymer being modified with a specific compound; an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component; and the silane coupling agent contains a mercapto group.

The purpose of the present invention is to provide a rubber composition with which it is possible to produce a tire that retains wear resistance and has excellent frictional force on ice, and a pneumatic tire using the rubber composition. The rubber composition of the present invention is a rubber composition comprising a diene rubber, carbon black and/or a white filler, and a master batch prepared by premixing a non-diene rubber and an organic peroxide, wherein a total content of carbon black and white filler is from 20 to 70 parts by mass per 100 parts by mass of diene rubber and a content of the non-diene rubber in the master batch is from 3 to 30 parts by mass per 100 parts by mass of the diene rubber.

What is provided is a tire vulcanizer, in which the stress force during engagement of the teeth can be reduced and teeth damage can be suppressed, allowing down-sizing, light-weighting, and simplifying at the same time. It includes: an upper mold attaching part (21) to which an upper mold is attached; a lower mold attachment part to which a lower mold pressed on the upper mold is attached; a supporting part (5) that supports the upper mold attaching part (21) and the lower mold attaching part; a fixed side rack (6) having first teeth (6a) arranged in a height direction and provided to the supporting part (5); a movable-side rack (7) having second teeth (7a) engaging with the first teeth and provided to the upper mold attaching part (21); and a tilting restriction part (40) restricting tilt of the movable-side rack (7) derived from the height direction.

Provided is a rigid core for forming a tire, configured so that the intrusion of rubber into a gap between core segments is prevented and so that the lowering of roundness of a core body s prevented. The core body comprises a plurality of circumferentially divided core segments. Both circumferential end surfaces of each of the core segments are used as mating surfaces, and the mating surfaces adjacent to each other in the circumferential direction are abutted against each other to form the core body. At least one of the mating surfaces adjacent to each other in the circumferential direction is formed as a stepped mating surface comprising a bordering surface region extending along an outer circumferential edge of the mating surface, and a recessed surface region surrounded by the bordering surface region and recessed in a step shape from the bordering surface region so that only the bordering surface region contacts with the adjacent mating surface.

A rigid core for forming a tire is configured so that the non-uniformity of the amount of thermal expansion of the core body is reduced to improve the quality of the tire. The core body comprises divided core pieces (10i , 10o) divided inward and outward in a tire radial direction at a tire radial position (P) including a maximum width position (P0) of the tire forming surface. Outward divided core pieces (10o) disposed outward in the tire radial direction than the maximum width position (P0) and inward divided core pieces (10i) disposed inward in the tire radial direction than the maximum width position (P0) are respectively formed of metal materials different from each other in coefficient of thermal expansion. The coefficient of thermal expansion of the inward divided core piece (10i) is higher than a coefficient of thermal expansion of the outward divided core piece (10o).

The present invention relates to a developable bottom antireflective coating (BARC) composition and a pattern forming method using the BARC composition. The BARC composition includes a first polymer having a first carboxylic acid moiety, a hydroxy-containing alicyclic moiety, and a first chromophore moiety; a second polymer having a second carboxylic acid moiety, a hydroxy-containing acyclic moiety, and a second chromophore moiety; a crosslinking agent; and a radiation sensitive acid generator. The first and second chromophore moieties each absorb light at a wavelength from 100 nm to 400 nm. In the patterning forming method, a photoresist layer is formed over a BARC layer of the BARC composition. After exposure, unexposed regions of the photoresist layer and the BARC layer are selectively removed by a developer to form a patterned structure in the photoresist layer. The BARC composition and the pattern forming method are especially useful for implanting levels.

An optical film has a cellulose acylate film base material containing cellulose acylate and a plurality of sugar ester compounds having different ester substitution degrees in which an average ester substitution degree of the plurality of sugar ester compounds is from 60 to 94%, and an antistatic hardcoat layer formed from a coating composition containing at least an organic antistatic agent and a curable compound having a (meth)acryloyl group in a molecule of the curable compound.

The present invention aims to provide a technique that prints characters and patterns clearly onto a tire surface without complicated operations. A tire printing device of the present invention includes a printer head that ejects and applies a coating material onto a tire surface, a widthwise moving unit that moves the printer head along the width direction of the tire, a radial moving unit that moves the printer head along the radical direction of the tire, and a swinging unit that swings the printer head around the axis along the circumferential direction of the tire.

A tire inflation system including a drive mechanism having a rotational axis, a pump cavity positioned a radial distance away from the axis of rotation, and a force translator coupling the rotational axis to the pump cavity. The drive mechanism includes a cam comprising an arcuate bearing surface having a non-uniform curvature, the cam rotatable about the rotational axis, and an eccentric mass couple to the cam that offsets a center of mass of the drive mechanism from the rotational axis. The pump cavity is rotatably coupled to the cam, wherein the pump cavity includes an actuating element and a chamber. The force translator couples the arcuate bearing surface to the actuating element, wherein the force translator includes an axis having an arcuate position fixed to an arcuate position of the pump cavity.

A tire inflation system including a drive mechanism having a rotational axis, a pump cavity positioned a radial distance away from the axis of rotation, and a force translator coupling the rotational axis to the pump cavity. The drive mechanism includes a cam comprising an arcuate bearing surface having a non-uniform curvature, the cam rotatable about the rotational axis, and an eccentric mass couple to the cam that offsets a center of mass of the drive mechanism from the rotational axis. The pump cavity is rotatably coupled to the cam, wherein the pump cavity includes an actuating element and a chamber. The force translator couples the arcuate bearing surface to the actuating element, wherein the force translator includes an axis having an arcuate position fixed to an arcuate position of the pump cavity.

An apparatus for enhancing traction for two drive wheels of a self-propelled vehicle, wherein the kit includes a reservoir coupled to a primary conduit through selective actuation of a solenoid valve. The primary conduit is in fluid communication with a secondary conduit, wherein the secondary conduit includes a spray head positioned adjacent each drive wheel of the vehicle. The spray head includes an apertured semi-spherical spray head to disperse fluid to and adjacent the drive wheels to effect melting of snow and ice thereabout. The kit further includes a dispersion brush selectively securable about the nozzle to minimize dirt and debris intrusion into the spray head, and further includes elastomeric cap member to overlie the spray head and enclose the same during periods of non-use.

An anti-hydroplane system for tires that includes a blower assembly in front of each of the tires of a vehicle. Each blower assembly discharges a high pressure stream into a water dispersal area in front of a respective one of the vehicle tires.

Disclosed is a cap unit wherein safety is increased by preventing a reversed flow of a puncture-sealing agent. A cap main body (33) comprises an air flow passage (31) consisting of a vertical flow passage (31A) extending downward from an air passage upper opening (31a), a lateral flow passage (31B) laterally extending from an air intake port (31b), and a connecting flow passage (31C) connecting therebetween. The air flow passage (31) is provided with a reversed flow preventing device (22). The cap main body (33) is provided with a vertical hole (40) consisting of first to fourth vertical holes (40A to 40D) which have inner diameters increasing downwardly from the upper end in a stepwise manner, and the first to third vertical holes (40A to 40C) form the vertical flow passage (31A).

A disposal method for entirely recycling solid refuse includes the following steps: sorting, crushing, drying, pressing with high pressure to shaped articles, producing charcoal from combustible refuse in high temperature and firing incombustible refuse in high temperature, at last cooling high temperature articles to obtain solid fuel with various shapes and bricks or board used for building. The method achieves entirely recycling house refuse, especial solid refuse. The method recycles solid refuse to obtain fuel and building material with economic value. The method is simple and its processing cost is low.

A system for tire distillation including an upper chamber, a first conveyor configured to transport a tire through the upper chamber, a lower chamber located beneath the upper chamber, the lower chamber that includes an ultrasonic purge chamber configured to radiate the tire with ultrasonic radiation, a microwave radiation chamber configured to radiate the tire with microwave radiation, and a second conveyor configured to transport the tire from the ultrasonic purge chamber to the microwave radiation chamber. The system further includes a vacuum system configured to maintain an atmosphere in the ultrasonic purge chamber and the microwave radiation chamber under a vacuum wherein the tire is preheated during conveyance through the upper chamber from heat produced in the lower chamber.

A pneumatic tire for improving steering stability performance on dry and wet road surfaces. The tire tread pattern has circumferential center main grooves, outside and inside main grooves, land sections demarcated by the main grooves, ground contact borders on both sides of the tire, and closed shoulder lug grooves. A ratio Wmax/Wout of a maximum main groove width Wmax and an outside main groove width Wout is at between 1.5 and 2.5 inclusive. A ratio Sin/Sout of a groove area ratio Sin of a region on a tire-widthwise second side of a tire centerline and a groove area ratio Sout of a region on a first side of the tire centerline is at least 1.10 and smaller than 1.25. A groove area ratio of a region on the second side of a tire-widthwise centerline of the intermediate land sections exceeds that of a region on the first side.

A non-pneumatic tire for supporting a load by working in tension comprising a generally annular inner surface, a generally annular outer ring, and an interconnected web having a plurality of web elements and comprising a plurality of generally polygonal openings. Web elements are sized, oriented and comprised of a material that facilitates buckling when subjected to a compressive load. By buckling, those elements in a deformed portion of the tire between a hub and a footprint region where the tire contacts a surface may assume a significantly reduced portion of the load, if any. This causes web elements in other portions of the interconnected web to operate in tension to support the load. With the portion of the tire in the footprint region not bearing a significant portion of the load, non-pneumatic tire may exhibit a more comfortable ride subject to less noise and vibration and improved handling capabilities.

A pneumatic tire in which an inner liner including a film mainly made of thermoplastic resin is attached to an inside of the tire via a tie rubber sheet, on an inner side of a carcass layer, and which has a lap-splice portion where end portions of the film in a tire circumferential direction overlap each other in a tire widthwise direction with tie rubber therebetween. A section of the film on a tire cavity side in the lap-splice portion has a portion where the film is thin over part or entirety of the width in the tire widthwise direction before the lap-splice portion, or a film thickness in the lap-splice portion is smaller than a film thickness in a portion other than the lap-splice portion. Thus, the pneumatic tire has no crack developing around the lap-splice portion of an inner liner layer after running, and has excellent durability.

A motorcycle tire comprises a tread portion grooved so that twenty narrow annular zones thereof each have a land ratio of 70 to 90%, wherein the twenty narrow annular zones are defined by equally dividing the developed tread width along the tread face by twenty. On each side of the tire equator, main oblique grooves and auxiliary oblique grooves are arranged alternately in the tire circumferential direction and inclined to one tire circumferential direction. The main oblique grooves on each side of the tire equator extend beyond the tire equator to have axially inner ends located on the other side of the tire equator. The auxiliary oblique grooves on each side of the tire equator do not extend beyond the tire equator to have axially inner ends located on the same side of the tire equator.

It is a problem to provide a pneumatic tire where disengagement between sipe wall surfaces is suppressed. In a sipe formed in a block of a tread portion, two ridge portions (32) and (34) are formed in one sipe wall surface (29P), and two valley portions that engage with the ridge portions (32) and (34) are formed in another sipe wall surface. The two ridge portions (32) and (34) form a merged portion (30) where they merge together in the center of a sipe lengthwise direction and at their tire radial direction outside ends, and the two ridge portions (32) and (34) extend linearly from the merged portion (30) toward both sipe-lengthwise-direction end sides (F) and (K) so as to gradually move apart inward in the tire radial direction. Because of this configuration, the contact length of the adjacent sipe wall surfaces in a sipe depth direction (R) becomes longer.

In a pneumatic tire, center land portions include a circumferential narrow groove extending in the tire circumferential direction so as to partition the center land portions in a tire width direction; a plurality of lug grooves disposed in each region of each of the center land portions partitioned by the circumferential narrow groove, extending in the tire width direction, so as to partition each of the regions of the center land portions in the tire circumferential direction; and a plurality of blocks partitioned by the circumferential narrow groove and the plurality of lug grooves. Blocks of the center land portions include one open sipe extending in the tire width direction so as to partition the blocks in the tire circumferential direction, and three or more closed sipes disposed in each of the regions of each of the blocks partitioned by the open sipe.

A pneumatic radial tire in which a plurality of land portion rows 2 are formed by a plurality of main grooves that extend in the circumferential direction on a tread portion of a tire, and a thin groove 3 that extends in the tire circumferential direction is formed in at least one shoulder land portion row 2A that is positioned on the tread end among the plurality of land portion rows. A land portion 5 that is positioned between, the thin groove 3 and the tread end 4 is partitioned into a plurality of blocks 5a by a lug groove 6 that extends in the tire width direction and whose maximum groove depth is set deeper than the groove depth of the thin groove, and the groove depth of the lug groove continuously changes so as to become a maximum at an intermediate position between the thin groove and the tread end. According to the present invention, it is possible to provide a pneumatic radial tire that can achieve improved drainage performance.

Tyre and rubber composition for tyre, based on at least one isoprene elastomer (for example natural rubber), an inorganic filler as reinforcing filler (for example silica) and a coupling system which provides the bonding between the said reinforcing inorganic filler and the isoprene elastomer, the said coupling system comprising, in combination: as first coupling agent, a silane sulphide compound;as second coupling agent, an at least bifunctional organosilicon compound (for example an organosilane or an organosiloxane) which can be grafted to the elastomer by means of an azodicarbonyl functional group (—CO—N═N—CO—).

A method for locking a tire to a wheel rim, includes the steps of mounting a tubular tire locking element on the wheel rim, which tubular locking member is arranged with a valve, which valve is pushed through a hole in the rim; mounting a tire on the rim such that the tire encloses the tubular tire locking element and a pressure chamber is obtained between the tire locking element and the tire; pressurizing the tubular tire locking element via the valve such that it expands, whereby the beads of the tire are pressed against the flanges of the wheel rim; inserting a hollow needle through the tire and into the pressure chamber, which hollow needle is connected to a pressurized air source; pressurizing the pressure chamber to desired pressure, removing the hollow needle; and sealing the hole caused by the needle with sealing fluid or plug.

A pneumatic tire is provided with a main groove extending along a tire circumferential direction in a tread. A side wall of a land portion facing the main groove extends so as to be inclined with respect to a tire circumferential direction between a pair of corner portions. The corner portion positioned in an inner side in a width direction of the main groove is set to an inner corner portion and the corner portion positioned in an outer side is set to an outer corner portion. In the inner corner portion, the side wall is formed by a stepped surface expanding to the outer side in the width direction toward a groove bottom and an expansion to the outer side in the width direction in the stepped surface is made smaller from the inner corner portion toward the outer corner portion.

A pneumatic tire including at least four circumferential main grooves extending in the tire circumferential direction and a plurality of rib-like land portions partitioned by the circumferential main grooves in the tread portion. Additionally, an outer side second land portion includes a zigzag narrow groove having a zigzag shape, extending in the tire circumferential direction, and dividing the outer side second land portion in the tire width direction; and a plurality of first sipes disposed at a predetermined pitch in the tire circumferential direction, extending from an edge portion on the outer side in the tire width direction of the outer side second land portion toward the inner side in the tire width direction, and terminating prior to the zigzag narrow groove, leaving a gap for ventilation.

A pneumatic tire including a separatable pair of mechanical fasteners wherein a first fastener of the pair of mechanical fasteners is provided on a tire inner surface. In this pneumatic tire, the obtained engagement force of the pair of mechanical fasteners is great and is essentially free of variations (positional variation within the tire and variation from tire to tire); the engagement force deteriorates/declines minimally over time due to extreme usage conditions including repetitive deformation and compaction over an extended period of time caused by tire rotation at high speeds in a state of relatively elevated temperatures; and the desired engagement force can be maintained over an extended period of time.

The present invention includes a run-flat tire 1 comprising a plurality of turbulence generation ridges 20 which extend on a surface of a tire side portion 3 in a tire-radial direction and which are arranged at a pitch in a tire-circumferential direction and relationship Si>So is satisfied. Si is the sum of sidewall areas of all the turbulence generation ridges located at the inner side, in the tire-radial direction, of a maximum width position of the pneumatic tire. So is the sum of sidewall areas of all the turbulence generation ridges located at the outer side, in the tire-radial direction, of the tire maximum width position.

Bicycle tires with at least one reinforcement layer that contains strength supports and that is arranged between carcass and tread rubber and/or between carcass layers below the tread rubber and/or within the tread rubber. For a high resistance to puncturing with low weight, the reinforcement layer contains multifilament threads of more than 30 polyester/polyarylate filaments, and the filaments are spun from molten liquid-crystal polymer.

Particular embodiments of the present invention include a multi-stage tire tread having a plurality of wear layers, each said layer being located at a different depth of the tire tread, the tread including one or more tread elements including a contact surface and having a first wear layer and a second wear layer, wherein the second wear layer is located below the first wear layer. The tire tread also includes a longitudinal groove extending in a longitudinal direction within the second wear layer of the tread element, wherein said longitudinal groove becomes exposed after a depth of the first wear layer has been worn. The tire tread further includes one or more lateral grooves extending from the longitudinal groove in a lateral direction within the second wear layer of the tread element. The invention also provides a mold element for forming portions of the multi-stage tread.

A tire having a tread includes an outer tread layer and an inner tread layer. The inner tread layer includes one of a first elastomeric compound and a second elastomeric compound. The outer tread layer includes the other of the first and second elastomeric compounds. The second elastomeric compound has a lower rolling resistance and greater resistance to treadwear than the first elastomeric compound. The inner tread layer increases in thickness across at least a widthwise portion of the outer tread layer with a maximum thickness of one of the inner tread layer and the outer tread layer occurring near at least one of a first shoulder and a second shoulder of the tread. As the tread wears, the inner tread layer defines a greater proportion of a running surface of the tread.

A tire (10) for driving on ice, comprising: a tread (20) having a rolling surface configured to come into contact with the ground when the tire is rolling along, and two lateral faces (27), this tread comprising at least one groove (25, 26) in the rolling surface; at least one stud (30) having a longitudinal axis (33), a part (31) of the stud projecting from the rolling surface, the intersection between the stud and the plane tangential to the portion of the rolling surface around the stud forming a contour C, that part of the stud that projects from the rolling surface having a minimum cross section Sm, Sm corresponding to the smallest cross section of the said part in any plane containing the radial direction that passes through the point of intersection between the longitudinal axis of the stud and the plane tangential to the portion of the rolling surface around the stud; at least one conduit (200-205) that forms, on the rolling surface of the tire, at least two opposing edges (211, 221; 212, 222; 213, 223), the minimum distance D between the conduit and the contour C being less than or equal to 1 cm, 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.

A pneumatic tire that is provided with a first fastener of a separatable pair of mechanical fasteners on a tire inner surface, wherein, even in cases where a desired object is engaged/fixed using only one fastener, the object does not rotate having the fastener as a central axis when the tire is in use. A first fastener of the pair of mechanical fasteners is provided on a tire inner surface, and the mechanical fasteners are provided with a rotation preventing mechanism for preventing the fasteners from mutually rotating when the pair of mechanical fasteners are engaged.

A rubber composition for tire treads is obtained by blending, per 100 parts by mass of a diene rubber, 5 to 150 parts by mass of silica and 0.5 to 20 parts by mass of a silicone oligomer represented by the following siloxane average formula (1): (X)a(Y)b(R1)c(R2)dSiO(4-a-b-c-d)/2 (wherein X is a mercapto group-containing organic group; Y is a hydrolyzable group, R1 is a monovalent hydrocarbon group having from 4 to 10 carbon atoms, R2 is a monovalent hydrocarbon group having from 1 to 3 carbon atoms, 0

The present invention provides a rubber composition that improves in terms of the fuel economy of a rubber composition containing an isoprene-based rubber and also offers favorable durability and favorable processability or adhesion to steel cords, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for a bead apex, sidewall packing, base tread, or breaker cushion, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of sulfur; and a specific amount of a compound represented by formula (I) below. The present invention also relates to a rubber composition for a steel cord topping, strip adjacent to steel cords, or tie gum, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of an organic acid cobalt salt; and a specific amount of a compound represented by the formula (I).

A tire has a circumferential tread, the tread including shoulder tread regions configured for off-road performance separated by and interlocking with a center tread region configured for on-road performance. The shoulder tread regions are defined by a repeating pattern of two or more distinct shoulder tread elements and the center tread region is defined by a repeating pattern of two or more distinct center tread elements. The shoulder tread elements each have a ground contacting surface area greater than a ground contacting surface area of the center tread elements. The center tread elements extend at a relatively greater angle of inclination with respect to an equatorial centerplane of the tire and the shoulder tread elements extend at a relatively lesser angle of inclination with respect to the centerplane. The center tread elements and the shoulder tread elements are irregular and asymmetrical about a longitudinal central axis and a transverse central axis and, together, total five or more (three in the center tread region and two in the shoulder tread region) tread blocks of mutually distinctive geometric shape.

Provided is a pneumatic tire whose braking performance on ice and partial-wear resistance can be improved. Sipes 11X provided in a rib 5 on a tire equatorial plane TE are formed in such a three-dimensional shape that the amount at which the rib 5 collapses due to an external force is smaller in the tire rotational direction than in a direction opposite to the tire rotational direction. In each block 10 in each shoulder region 1S, sipes 11Ma in a block tread-in side portion 10A are each formed in such a three-dimensional shape that the amount at which the block 10, if entirely provided with the sipes 11Ma, collapses due to an external force will be smaller in the tire rotational direction than in the direction opposite to the tire rotational direction. Sipes 11Mb in a block kick-out side portion 10B are each formed in such a three-dimensional shape that the amount at which the block 10, if entirely provided with the sipes 11Mb, collapses due to an external force will be smaller in the direction opposite to the tire rotational direction than in the tire rotational direction.

A heavy duty tire comprises a tread portion provided with tread blocks each provided in the ground contact surface thereof with a single zigzag sipe. A ratio A/B of a block length (A) which is the circumferential length of the block measured along a straight line passing through the centroid of the ground contact surface to a maximum block width (B) which is the axial distance between the axial extreme ends of the ground contact surface is 0.8 to 1.7. The zigzag sipe is disposed within a central region which is defined as extending from the centroid of the ground contact surface towards each side in the tire circumferential direction by 25% of the block length (A). The zigzag sipe is composed of a pair of major straight segments extending axially inwardly from both sides of in the tire axial direction of the block, and a minor straight segment extending between the inner ends of the respective major straight segments, so that the circumferential distance between the circumferential extreme ends of the sipe is in a range of from 10 to 35% of the block length (A).

A heavy duty pneumatic tire comprises a tread portion provided with circumferentially continuous main grooves and lateral grooves to form blocks in circumferential rows. The main grooves include a pair of shoulder main grooves disposed one on each side of the tire equator so that the center line thereof is at a distance of 0.30 to 0.65 times one half of the tread width from the tire equator. The blocks include crown blocks disposed in a tread crown region between the shoulder main grooves, and shoulder blocks disposed in shoulder regions axially outside the shoulder main grooves. Each of the crown blocks and shoulder blocks is provided with at least one axially extending sipe.