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    • 专利摘要:
    TIRE Tire comprising a tread (2) provided with blocks (201-204) formed between substantially longitudinal (205 - 207) and transverse grooves, wherein between the blocks particularly wide intersections (212) are formed, for example, by alternating. if substantially transverse grooves of circumferential rows axially relative to side by side blocks with rounded corners and wherein within such wide intersections (212) a squat shaped bulge (216) is arranged, which has a lateral stiffness greater than the stiffness side of the surrounding blocks (201 - 204).
    公开号:BR112013014269B1
    申请号:R112013014269-3
    申请日:2011-12-19
    公开日:2021-07-06
    发明作者:Claudio Minoli；Tommaso Pizzorno；Alessandro Canelli
    申请人:Pirelli Tyre S.P.A.；
    IPC主号:
    专利说明:

    field of invention
    [1] The present invention relates to a tire for vehicle wheels, particularly for wheels of heavy load vehicles. Even more particularly, the present invention relates to tires for wheels of heavy load vehicles, intended for a so-called "inside-outside" use, i.e. vehicles used both on normal road routes and on off road routes, typically in dirty roads, in quarries or construction yards. State of the art
    [2] The following documents describe some tires for wheels of heavy load vehicles: WO 01/39994, WO 2008/064703, US 5896905, US 6176284. Invention Summary
    [3] Tires for wheels of heavy load vehicles, which alternate covered distances on asphalted roads with extensions of unpaved roads or construction yards, have to face, particularly during winter or spring, the problem of low traction because of of filling the tread furrows with mud, which is trapped there while traveling on off-road paths.
    [4] On treads with very wide grooves, the problem of entrapment of mud practically does not arise. However, such tires are mainly used for off-road purposes.
    [5] Tires for heavy-duty vehicles, used primarily on paved roads and only minimally on off-road routes (eg, quarry-construction yard vehicles such as concrete mixers or dumpers), however, typically have ruts. narrower, so as not to penalize too much performance in terms of comfort (both acoustic and vibrational) and life span (wear) when moving on paved areas.
    [6] In this kind of tires, mud entrapment is a problem, as the unexpelled mud becomes compacted in the tread grooves, rotation after rotation, worsening the traction aspects of the tire, because of the substantial loss. pressure conditions, which are generated at the ends of the blocks and allow the grip on the bearing surface to be maximized.
    [7] In addition, the trapped and compacted mud fills the entire intersection and part of the surrounding furrows with extremely thick material, until the tread becomes substantially smooth, which can cause serious problems when traveling in a wet and /or slippery.
    [8] The problem of providing a tread for a tire for wheels of heavy load vehicles, intended for use both on common road paths (asphalted) and on off-road paths, was faced, capable of providing said tire with good performances in terms of traction, comfort and noise level in an asphalted area and, at the same time, effectively expel pieces of mud that are trapped in the ruts when passing in muddy areas, in order to keep the traction aspects on muddy areas substantially unchanged and safety aspects when traveling in a wet and/or slippery area.
    [9] It has been found that such a problem can be solved by means of a tread provided with blocks formed between substantially longitudinal and transverse grooves, in which particularly wide intersections are formed between the blocks, for example, alternating substantially transverse grooves of circumferential rows, axially relative to each other, of blocks with rounded corners, and wherein within such wide intersections a squat-shaped bulge is arranged, having a lateral stiffness greater than the lateral stiffness of the surrounding blocks.
    [10] Here and in the rest of the description, by "lateral stiffness" we mean a force per unit displacement required for the blocks or protrusion to move in a generic direction lying in a plane perpendicular to a radial direction of the tire (for example , a circumferential or axial direction), typically in the plane of the radially outer surface of the tread band.
    [11] Lower mobility corresponds to higher lateral stiffness, and vice versa.
    [12] Surprisingly it has been found that the wide intersections mentioned above do not cause any substantial increase in the noise level and/or vibrations generated by the tire when rolling over an asphalted area and, advantageously, provide the tire with a series of grip fronts , when running in a muddy area.
    [13] The squat-shaped bulge allows the respective wide intersection to be released from the mud that is trapped when passing through a roof area because of the suction effect caused by the mutually approaching motions of block walls. In particular, when leaving the cover area, the blunt, rigid bulge - under the action of the underlying belt structure - gives rise to a thrust in the radial direction over the possibly trapped mud in order to effectively expel it.
    [14] In addition, the different lateral stiffness of the bulge and surrounding blocks causes relative movement between the movable walls of the surrounding blocks and the substantially fixed bulge, whose movement prevents the compaction of the mud, which is possibly trapped in the wide intersection at the pass in the coverage area, causing cracking, cracking and/or rupture of the trapped mud. The expulsion of the trapped mud itself, when leaving the cover area, is thus promoted.
    [15] The tire tread thus remains substantially clear of trapped mud at all times, in order to keep its traction aspects substantially the same in all areas it passes through.
    [16] In a first aspect, the invention relates to a method for promoting traction of a tire on a muddy surface, wherein the tire comprises a tread and the tread comprises a plurality of blocks formed between a a plurality of substantially transverse grooves and a plurality of substantially longitudinal grooves. The substantially transverse and substantially longitudinal grooves form a plurality of intersections between said blocks.
    [17] The method comprises forming at least one wide intersection comprising a respective portion of a radially inner surface of the tread having a significant dimension. The wide intersection is such as to allow an ellipse to be inscribed therein, said ellipse having longer geometric axes than a width of both the substantially transverse grooves and the substantially longitudinal grooves forming the wide intersection. In particular, at least one of the geometric axes of the inscribable ellipse has a length equal to at least 1.5 times the width of both the substantially transverse grooves and the substantially longitudinal grooves forming the broad intersection.
    [18] The method further comprises arranging - at said wide intersection - a squat shaped protrusion, projecting from the radially inner surface of said tread. The bulge has a volume less than the volume of the blocks surrounding the wide intersection and is such as to provide said bulge with a lateral stiffness greater than the lateral stiffness of the surrounding blocks.
    [19] When the tire is placed in rolling condition on a muddy surface, a piece of mud is trapped within the wide intersection, while the wide intersection passes into the coverage area, by means of a first movement of mutual approximation of the surrounding blocks the wide intersection.
    [20] The expulsion of such a piece of mud from the wide intersection, after the wide intersection has left the coverage area, is promoted by means of a second movement of mutual separation of the blocks surrounding the wide intersection, in combination with a thrust in the direction radial, caused by the bulge arranged at the wide intersection.
    [21] According to a second aspect thereof, the invention relates to a tire comprising a tread, wherein said tread comprises a plurality of blocks formed between a plurality of substantially transverse grooves and a plurality of substantially longitudinal grooves . The substantially transverse and substantially longitudinal grooves further form a plurality of intersections between said blocks.
    [22] The plurality of intersections formed between the blocks comprise large intersections. Each wide intersection comprises a respective part of a radially inner surface of the tread, having a significant dimension and being such as to allow an ellipse to be inscribed therein, said ellipse having geometric axes longer than the width of both said grooves substantially transverse and of said substantially longitudinal grooves forming the wide intersection. At least one of the geometric axes of said inscribed ellipse at the wide intersection has a length equal to at least 1.5 times the width of both the substantially transverse grooves and the substantially longitudinal grooves forming the wide intersection.
    [23] At each wide intersection, a squat-shaped bulge is arranged, protruding from the radially inner surface portion of the tread. The squat shape, that is, a shape with a width greater than the height of the bulge, increases its lateral stiffness.
    [24] The bulge still has a smaller volume than the volume of the blocks surrounding the wide intersection and in order to provide said bulge with greater lateral stiffness than the lateral stiffness of the blocks surrounding the wide intersection.
    [25] The bulge thus forms a solid and stable piece, with no thin parts that would increase its overall mobility.
    [26] Preferably, the blocks can be arranged - on the tread - according to a plurality of circumferential rows axially in side-by-side relationship.
    [27] Preferably, the wide intersections are formed between at least one pair of adjacent circumferential rows of blocks, comprising transverse grooves alternating in the transverse direction.
    [28] Even more preferably, wide intersections are formed between at least two pairs of adjacent circumferential rows of blocks. Each pair of circumferential rows may comprise transverse grooves alternating in the transverse direction.
    [29] For example, wide intersections can be formed between two axially outer pairs of circumferential rows of tread blocks.
    [30] In one embodiment, the tire comprises at least four circumferential rows of blocks, axially in side-by-side relationship. Said at least four circumferential rows of blocks may preferably divide the width of the tread into respective at least four parts of substantially the same width. By “tread width” we mean the distance between the axially outer edges of the radially outer profile of the tread.
    [31] It was observed that this arrangement advantageously allows the contact pressures between the tire and the rolling surface in the coverage area to be equalized.
    [32] The protrusion arranged at the wide intersections projects from the radially inner surface of the tread at a height preferably less than the depth of the respective wide intersection. For example, such height can be between 25% and 75% of the depth of the respective wide intersection. The height of the bulge, less than the depth of the wide intersection, increases the lateral stiffness of the bulge itself, which does not come into contact with the area when passing through the coverage area, in order to remain stably attached to the strap structure underlying the band. of shooting.
    [33] The base surface of said protrusion preferably has a size at least equal to 40% of the length of the minor axis of the inscribable ellipse at the respective wide intersection. This makes it possible to occupy a larger part of the radially inner surface of the tread comprised at the wide intersection by means of the bulge, as well as to form an extremely stable bulge.
    [34] In a preferred embodiment, the shape of said protrusion is frusto-conical.
    [35] Preferably, the profile of the base surface of said protrusion is spaced from the walls of the blocks surrounding the respective wide intersection. This solution makes the walls of the blocks surrounding the wide intersection independent of the protrusion, thus promoting relative movement between the block walls and the protrusion, to prevent the compaction of possible mud trapped in the wide intersection itself.
    [36] Preferably, at least the blocks surrounding said wide intersection comprise an inclined front wall. Such sloping front wall may comprise at least one step, more preferably a plurality of steps. Here and in the rest of the description, by “front wall” of a block we mean the wall of the block destined to first enter the coverage area. Furthermore, by "sloping wall" we mean a wall having a radially outer corner, not radially aligned with the corresponding corner (or joining surface) on the radially inner surface of the tread. Such a sloping wall does not necessarily have a smooth surface and, as mentioned above, may have steps. The presence of steps on the walls of the blocks surrounding the wide intersections can also promote the expulsion of the mud trapped in the wide intersections and, possibly, in the surrounding furrows.
    [37] Preferably, in the tire according to the present invention, the ratio between the total surface area, taken up by the blocks, and the total surface area of the tread is at least equal to 60%. Typically, this ratio is less than 80%.
    [38] Preferably, the longitudinal and/or transverse grooves surrounding said wide intersections have a width not greater than about 25 mm on the radially outer surface of the tread. Preferably, the longitudinal and/or transverse grooves surrounding said wide intersections have a width of not less than about 6 mm on the radially outer surface of the tread.
    [39] The following definitions still apply in this description.
    [40] By “equatorial plane” of the tire we mean a plane perpendicular to the geometric axis of rotation of the tire and dividing the tire into two symmetrically equal parts.
    [41] By “circumferential” or “longitudinal” tire direction we mean a direction generally directed in accordance with the direction of rotation of the tire, or in any case only slightly inclined with respect to the direction of rotation of the tire (typically with an angle less than 45o with respect to the direction of rotation of the tire).
    [42] By “axial” direction we mean a direction parallel to the geometric axis of rotation of the tyre.
    [43] By "transverse" direction we mean a direction generally directed according to an axial direction, or in any case according to a direction only slightly inclined with respect to the axial direction (typically with an angle less than 45° with respect to the axial direction.
    [44] Furthermore, any value relative to the angles formed by the longitudinal and/or transverse grooves with respect to the predetermined direction is always to be understood as an absolute value. Brief description of the figures
    [45] Other aspects and advantages of the invention will now be presented with reference to the embodiments shown as non-limiting examples in the accompanying figures, in which: • Fig. 1 is a top view of a tire having a tread made of according to an example of the invention. • Fig. 2 is a view of a part of the tire tread of Fig. 1. • Fig. 3a is an enlarged sectional view of the tread part of the tire shown in Fig. 2. The section is taken along line aa shown in Fig. 2. • Fig. 3b is an enlarged sectional view of a detail of the section of Fig. 3a. • Fig. 4 is an enlarged sectional view of a tread groove of the tire of Figs. 1 - 2. The section is taken along line b-b shown in Fig. 2. • Fig. 5 is a sectional view of the tire of Fig. 1. Detailed description of embodiments of the invention
    [46] In Figure 1 a tire for vehicle wheels according to the present invention, particularly a tire for wheels of heavy load vehicles, is generally indicated at 1. In particular, the tire 1 is adapted to be mounted on the axle. of heavy load vehicle traction. However, it is not excluded that it can also be mounted on the vehicle's steering axle. Tire 1 comprises a tread 2.
    [47] The tread 2 comprises a plurality of blocks formed between a plurality of substantially transverse grooves and a plurality of substantially longitudinal grooves. The blocks are arranged according to a plurality of circumferential rows axially in relation to each other.
    [48] Preferably, the tread 2 has a ratio between the total surface area occupied by the blocks and the total surface area of the tread at least equal to 60%. Typically, such a ratio is less than 80%. In the example shown in Figure 1, such a ratio is equal to about 69%.
    [49] The tread blocks 2 have a substantially polygonal shape (excluding the usual rounding of corners), preferably a convex polygon shape. Preferably, such polygons comprise four to eight sides.
    [50] In the embodiment shown in Fig. 1, the tire comprises four circumferential rows A, B, C, D of blocks, axially in side-by-side relationship. The four circumferential rows of blocks divide the width of the tread into respective four parts of substantially the same width. In other words, the blocks belonging to the circumferential grooves A, B, C, E have the same maximum width in the axial direction. This can correspond, for example, to a difference between the smallest and largest maximum width in the axial direction of the blocks of the circumferential rows A, B, C, D, which is less than 10 - 20% of the largest maximum width of the blocks themselves .
    [51] In the embodiment shown in Fig. 1, the circumferential rows A, B, C, D of the blocks are separated from each other by substantially longitudinal grooves with a zigzag course.
    [52] In each circumferential row A, B, C, D, the blocks are separated from each other by substantially transverse grooves. Such substantially transverse grooves may preferably be inclined with respect to the axial direction.
    [53] The tread 2 is preferably of the directional type, ie it has a preferred rolling direction, indicated by R.
    [54] As best shown below with reference to Fig. 2, the intersections between substantially longitudinal and substantially transverse grooves comprise particularly wide intersections, where the protrusions are arranged. In the embodiment shown in Figure 1, such wide intersections and such protrusions can be seen between the A-B and C-D pairs of circumferential rows of blocks.
    [55] As best shown in Figure 5, tire 1 comprises a carcass structure, including at least one carcass ply 103, formed by reinforcing cords, typically made of metal, embedded in an elastomeric matrix.
    [56] Carcass ply 103 has opposite end edges 103a fitted with respective bead cores 104. The latter are arranged in regions 105 of tire 1, commonly called "beads".
    [57] An elastomeric filler 106 (divided into two radially overlapping parts in the embodiment shown in Figure 5), absorbing the space defined between the carcass ply 103 and the respective extreme edge 103a of the carcass ply 103, is applied over the radially outer perimeter edge of the bead cores 104. The bead cores 104 keep the tire 1 firmly fixed in an anchorage location provided for this purpose on the wheel rim, thus preventing the bead 105 from leaving such a location during operation.
    [58] Beads 105 can be provided with specific reinforcing structures (such as, for example, fin 102), which have different functions, such as, for example, improving the transmission of torque to tire 1.
    [59] In a radially external position with respect to carcass structure 102, a strap structure 109 is applied, which preferably comprises several layers of strap (four layers 109i, 109ii, 109iii, 109iv are represented in the specific example shown) radially arranged one on top of the other and having reinforcing cords, typically made of metal, with a cross and/or substantially parallel orientation with respect to the circumferential direction of development of the tire 1. In the belt structure 109 of the tire shown in Figure 5, the layers 109ii, 109iii and 109iv comprise reinforcement cords oriented obliquely with respect to the tire's equatorial plane XX, while layer 109i comprises reinforcement cords oriented substantially in the circumferential direction (typically with an angle of less than 5 - 6° with respect to one direction parallel to the equatorial plane XX).
    [60] A tread 2, also made of an elastomeric material, is applied in a radially external position with respect to the belt structure 109.
    [61] On the side surfaces of the carcass structure 102, respective flanks 111, made of an elastomeric material, are further applied, each extending from one of the opposite side edges of the tread band 2 to the beads 105.
    [62] Figure 2 shows in greater detail a portion of the tread 2 of the tire of Fig. 1. Figure 3a shows a section of the tread 2 along the dashed line indicated by a-a in Figure 2.
    [63] Referring to Figure 2 and Figure 3a, the tread 2 comprises a plurality of blocks 201, 202, 203, 204.
    [64] Blocks 201 and 204 are arranged according to the respective circumferential rows A and D located in the axially outermost regions of tread 2.
    [65] Blocks 202 and 203 are arranged according to their respective circumferential rows A and C, in an axially internal position with respect to circumferential rows A and D.
    [66] Blocks 201, 202, 203, 204 are formed between a plurality of substantially transverse grooves 208, 209, 210, 211 and a plurality of substantially longitudinal grooves 205, 206, 207.
    [67] The substantially transverse grooves 208 circumferentially separate the blocks 201 of the axially outer circumferential row A from each other. Preferably, the transverse grooves 208 are slightly inclined with respect to the axial direction. For example, they can form an angle between 0o and 30o, preferably between 0o and 25o, with respect to the axial direction. In the example shown in Figure 2, the grooves 208 form an angle of about 14° with respect to the axial direction.
    [68] The substantially transverse grooves 209 circumferentially separate the blocks 202 of the axially inner circumferential row B from each other. Preferably, the transverse grooves 209 are slightly inclined with respect to the axial direction. For example, they can form an angle between 0o and 40o, preferably between 0o and 35o with respect to the axial direction. In the example shown in Figure 2, the grooves 209 form an angle of about 21° with respect to the axial direction.
    [69] Preferably, the angle formed by the substantially transverse grooves 209 of the axially inner circumferential row B of the blocks with respect to the axial direction is greater than the angle formed by the substantially transverse grooves 208 of the axially outer circumferential row A of the blocks with respect to the direction axial.
    [70] The substantially transverse grooves 210 circumferentially separate the blocks 203 of the axially inner circumferential row C from each other. Preferably, the transverse grooves 210 are slightly inclined with respect to the axial direction. For example, they can form an angle between 0o and 40o, preferably between 0o and 35o with respect to the axial direction. In the example shown in Figure 2, the grooves 210 form an angle of about 21° with respect to the axial direction.
    [71] The substantially transverse grooves 211 circumferentially separate the blocks 204 of the axially outer circumferential row D from each other. Preferably, the transverse grooves 211 are slightly inclined with respect to the axial direction. For example, they can form an angle between 0o and 30o, preferably between 0o and 25o with respect to the axial direction. In the example shown in Figure 2, the grooves 211 form an angle of about 14° with respect to the axial direction.
    [72] Preferably, the angle formed by the substantially transverse grooves 210 of the axially inner circumferential row C of the blocks with respect to the axial direction is greater than the angle formed by the substantially transverse grooves 211 of the axially outer circumferential row D of the blocks with respect to the direction axial.
    [73] Preferably, the substantially transverse grooves 208, 209, 210, 211 have a width, measured on the radially outer surface of the tread band 2, not greater than 25 mm. Preferably, the substantially transverse grooves 208, 209, 210, 211 have a width, measured on the radially outer surface of the tread band 2, not less than 6 mm. In the example shown in Figure 2, the grooves 208, 209, 210, 211 have a width of about 17-19 mm (a variation in width can be contemplated along the circumferential direction due to the variation in the circumferential extension of the tire tread two).
    [74] Preferably, the substantially transverse grooves 208, 209, 210, 211 have a depth of at least 20 mm, more preferably at least 22 mm.
    [75] Preferably, the substantially transverse grooves 208, 209 are inclined with respect to the axial direction at an angle of opposite sign with respect to the angle formed by the substantially transverse grooves 210, 211. In this way, the total of the substantially transverse grooves 208, 209 , 210, 211 forms an “arrow” with a tip pointing in the tire rolling direction, indicated by R in Figure 2.
    [76] Preferably, the substantially transverse grooves 208, 209 extend in alternating directions in the circumferential direction.
    [77] Preferably, the substantially transverse grooves 210, 211 extend according to stepped directions in the circumferential direction.
    [78] The substantially longitudinal grooves 205 separate in the axial direction the circumferential row A of blocks 201 from the circumferential row B of the blocks 202. Preferably, the substantially longitudinal grooves 205 are slightly inclined with respect to a direction parallel to the equatorial plane of the tyre. For example, they can form an angle between 0o and 30o, preferably between 0o and 25o with respect to a direction parallel to the equatorial plane. In the example shown in Figure 2, the grooves 205 form an angle of about 13° with respect to a direction parallel to the equatorial plane of the tire.
    [79] The substantially longitudinal grooves 206 separate in the axial direction the circumferential row B of the blocks 202 from the circumferential row C of the blocks 203. Preferably, the substantially longitudinal grooves 206 are slightly inclined with respect to a direction parallel to the equatorial plane of the tyre. For example, they can form an angle between 0o and 40o, preferably between 0o and 35o with respect to a direction parallel to the equatorial plane. In the example shown in Figure 2, the grooves 206 form an angle of about 24° with respect to a direction parallel to the equatorial plane of the tire.
    [80] The substantially longitudinal grooves 207 separate, in the axial direction, the circumferential row C of the blocks 203 from the circumferential row D of the blocks 204. Preferably, the substantially longitudinal grooves 207 are slightly inclined with respect to a direction parallel to the equatorial plane of the tire . For example, they can form an angle between 0o and 30o, preferably between 0o and 25o with respect to a direction parallel to the equatorial plane. In the example shown in Figure 2, the grooves 207 form an angle of about 13° with respect to a direction parallel to the equatorial plane of the tire.
    [81] Preferably, the angle formed by the substantially longitudinal grooves 206, with respect to a direction parallel to the equatorial plane, is greater than the angle formed by the substantially longitudinal grooves 205, with respect to a direction parallel to the equatorial plane.
    [82] Preferably, the angle formed by the substantially longitudinal grooves 206, with respect to a direction parallel to the equatorial plane, is greater than the angle formed by the substantially longitudinal grooves 207, with respect to a direction parallel to the equatorial plane.
    [83] Preferably, the substantially longitudinal grooves 205, 206, 207 have a width, measured on the radially outer surface of the tread 2, not greater than about 25 mm. Preferably, the substantially longitudinal grooves 205, 206, 207 have a width, measured on the radially outer surface of the tread band 2, of not less than about 6 mm. In the example shown in Figure 2, the grooves 205, 206, 207 have a width of about 7 - 8 mm.
    [84] Preferably, the substantially longitudinal grooves 205 are inclined with respect to a direction parallel to the equatorial plane at an angle of opposite sign with respect to the angle formed by the substantially longitudinal grooves 207.
    [85] Preferably, the substantially longitudinal grooves 206 circumferentially alternate their inclination with respect to a direction parallel to the equatorial plane, in order to form a zigzag groove extending between the circumferential rows B and C of blocks 202, 203.
    [86] Preferably, the substantially longitudinal grooves 205, 206, 207 have a maximum depth equal to the maximum depth of the substantially transverse grooves 208, 209, 210, 211.
    [87] In the preferred embodiment shown in Figures 2 and 3a, between blocks 201, 202, 203, 204 called "anchors", i.e. depth reductions in substantially longitudinal grooves 208, 209, 210, 211 are provided . Such a solution allows the rigidity of blocks 201, 202, 203, 204, in the axial direction, to be increased.
    [88] Preferably, greater depth reductions are provided in the substantially longitudinal grooves 206, located in an axially innermost position, compared to depth reductions provided in the grooves 205, 207, located in an axially outermost position.
    [89] For example, in substantially longitudinal grooves 205, between blocks 201 and 202, depth reductions can be provided of about 15 - 30% with respect to the maximum depth of the substantially transverse grooves; in substantially longitudinal grooves 207, between blocks 203 and 204, depth reductions of about 15 - 30% may be provided with respect to the maximum depth of the substantially transverse grooves; in substantially longitudinal grooves 206, between blocks 202 and 203, depth reductions can be provided of about 30 - 50% with respect to the maximum depth of the substantially transverse grooves.
    [90] The substantially transverse grooves 208, 209, 210, 211 and the substantially longitudinal grooves 205, 206, 207 form with each other a plurality of intersections between the blocks 201, 202, 203, 204.
    [91] The plurality of intersections formed between the blocks comprise particularly wide intersections. For the sake of simplicity, only one of these wide intersections is indicated in Figure 2 with reference to the numeral 212. In any case, similar wide intersections are clearly visible in Figure 2 among other blocks, in corresponding and/or symmetrical positions with respect to the wide intersection indicated by 212.
    [92] The wide intersections 212 can be generated in different ways. For example, they may be generated due to particularly pronounced rounding radii and/or chamfers of blocks 201, 202, 203, 204 at intersections. Additionally and/or alternatively, they can be generated due to staggering of particularly wide grooves. Additionally and/or alternatively, they can be generated due to the intersection of the grooves forming differently sloping walls in relation to each other in the surrounding blocks.
    [93] Each wide intersection 212 comprises a respective radially inner surface portion of the tread 2 adapted to allow an ellipse 213 to be inscribed thereon. Ellipse 213 can be designed to be tangent to the walls of blocks 201, 202 (and/or 203,204) on the radially inner surface of tread 2.
    [94] Such an ellipse 213 has a significant dimension (or area): the geometric axes 214, 215 of the ellipse 213 have a length greater than the width of both the substantially transverse grooves 208, 209 and the substantially longitudinal grooves 205 forming the intersection wide. For purposes of comparison with the geometric axes 214, 215 of the ellipse 213, the width of the substantially transverse grooves 208, 209 and the substantially longitudinal grooves 205 (and, more generally, of all the substantially transverse and substantially longitudinal grooves, forming the broad intersections 212) can be measured on the radially inner surface of the tread 2.
    [95] More particularly, at least one of the geometric axes 214, 215 of the ellipse 213 has a length equal to at least 1.5 times the width of both the substantially transverse grooves 208, 209 and the substantially longitudinal grooves 205 forming the wide intersection 212 In other words, at least one of the geometric axes 214, 215 of the ellipse 213 has a length greater than the maximum width of the grooves 208, 209, 205, which form - intersecting - itself. wide intersection 212. Referring to Figure 2, the axis 214 has the length clearly greater than 1.5 times the width of any of the grooves 208, 209 and 205, forming the wide intersection 212. More particularly, in the example shown in Figure 2, the major axis 214 of the ellipse 213 has a length equal to about 35 - 36 mm, while the minor axis 215 of the ellipse 213 has a length equal to about 23 - 24 mm.
    [96] A protrusion 216, having a stubby shape, is arranged at each broad intersection 212. The protrusion 216 projects from the radially inner surface portion of the tread 2, corresponding to the wide intersection 212. The stubby shape, ie, a shape with a width greater than the height of the bulge increases its lateral rigidity.
    [97] Protrusion 216 has a smaller volume than the volume of the surrounding blocks 201, 202, 203, 204, however the volume must be selected in order to provide protrusion 216 with greater lateral stiffness than the lateral stiffness of the blocks circling the wide intersection. In this regard, solid shapes without parts or thin overhangs are preferred for the protrusion 216: in this regard, shapes with ragged side profiles, such as cross-like profiles or the like, are not preferred. This allows the protrusion 216 to be formed as a solid, stable piece, substantially stationary with respect to the walls of the blocks 201, 202, 203, 204 surrounding the wide intersection 212, when these blocks enter and leave the coverage area during the rolling of the tire.
    [98] In a preferred embodiment, the shape of the protrusion 216 is substantially frusto-conical.
    [99] The protuberance 216, arranged at the wide intersections 212, projects from the radially inner surface of the tread 2 at a height preferably less than the depth of the respective wide intersection 212 (i.e. the depth of the tread 2 ). This is shown in the section of Figure 3a and in the enlarged view of Figure 3b. The height of the protrusion can be, for example, between 25% and 75% of the depth of the respective wide intersection 212. In the example shown in Figure 3b, the protrusion 216 has a height equal to about 29% of the depth of the wide intersection, where is located.
    [100] The height of the protrusion 216 less than the depth of the wide intersection 212 increases the lateral stiffness of the protrusion 216 itself. of cover, to remain stably attached to the belt structure underlying the tread 2. It remains substantially stationary with respect to the movements of the walls of the surrounding blocks 201, 201, 203, 204.
    [101] The base surface 217 of the protrusion 216 preferably has a size at least equal to 40% of the length of the minor axis 215 of the ellipse 213 inscribed at its wide intersection 212. This allows it to occupy a large part of the radially internal portion of the surface. of the tread 2 comprised at the wide intersections 212 by way of the protrusion 216, as well as forming an extremely stable protrusion. Also in this case, for the purpose of a comparison between the dimension of the base surface of the protrusion 216 and the length of the minor axis 215 of the ellipse 213, the latter can be measured on the radially inner surface of the tread band 2. In the example shown in Figures 2, 3a, 3b, the base surface 217 of the protrusion 216 has a dimension (diameter) equal to about 12 mm. On its radially outer surface, the protrusion 216 has a dimension (diameter) of about 8 mm.
    [102] Preferably, the outer profile of the base surface of the protrusion 216 is spaced from the walls of the blocks 201, 202, 203, 204 surrounding the respective wide intersections 212. This solution makes the walls of the blocks 201, 202, 203, 204, surrounding the wide intersection 212 independent of the protrusion 216, thus promoting relative movement between the walls of the blocks 201, 202, 203, 204 and the protrusion 216.
    [103] In the preferred embodiment shown in Figures 2 and 4, the blocks 201, 202, 203, 204, surrounding the wide intersections 212, comprise a sloped front wall. As can be seen from the section of Figure 4, such a sloping front wall 218 may preferably comprise a plurality of steps. The walls of such steps can be rounded in order to avoid the presence of corners that could cause the formation of cracks and/or fractures in the front wall 218 of the block.
    [104] When tire 1 is placed in rolling condition on a muddy surface, a piece of mud may be trapped within the wide intersections 212 as they pass through the coverage area. For example, mud entrapment can occur due to a mutual approach movement in the lateral direction of blocks 201, 202, 203, surrounding the wide intersections 212. Due to such movements in the lateral direction of blocks 201, 202, 203, 204, mud can be sucked in at wide intersections 212.
    [105] When each wide intersection 212 leaves the coverage area, a mutually separating motion of the surrounding blocks 201, 202, 203, 204 occurs.
    [106] Such a separating movement, in combination with a thrust in the radial direction, caused by the protrusion 216 arranged at the wide intersection 212, promotes the expulsion of the piece of mud trapped in the wide intersection 212. Such thrust is particularly effective due to the fact that that the protrusion forms a solid, rigid piece substantially anchored to the strap structure 109.
    [107] Furthermore, the different lateral stiffness of the protrusion 216 and the blocks surrounding 201, 202, 203, 204 causes a relative movement between the movable walls of the blocks 201, 202, 203, 204 and the substantially fixed protrusion 216. This movement prevents compaction of the mud possibly trapped at the wide intersections 212, causing cracking, cracking and/or disruption of the trapped mud itself. This further contributes to promoting the expulsion of the trapped mud itself when leaving the coverage area.
    [108] The presence of the steps in the walls, particularly the advancing walls 218, of the blocks 201, 202, 203, 204, surrounding the wide intersections 212, provide a rough contact surface for the mud trapped in the wide intersections 212 and possibly in the surrounding furrows 205, 206, 207. This can further promote the expulsion of trapped mud.
    [109] The tread 2 of tire 1 thus remains substantially always clear of the mud that is trapped while rolling, in order to keep its traction aspects substantially the same on all ground on which it rolls. In particular, the wide intersections 212 provide tire 1 with a series of grip fronts when rolling on muddy ground, in order to improve its traction aspects on this kind of often difficult and slippery ground.
    [110] On the other hand, it has surprisingly been found that the presence of the aforementioned wide intersections 212 does not cause any substantial increase in the noise level and/or vibrations generated by tire 1 when rolling over an asphalt ground.
    [111] The present invention has been described with reference to some of its embodiments. Many modifications can be made to the embodiments described in detail, while still remaining within the scope of protection of the invention, defined by the following claims.
    权利要求:
    Claims (10)
    [0001]
    1. Tire (1) comprising a tread (2), wherein said tread consists of a plurality of blocks (201, 202, 203, 204) formed between a plurality of transverse grooves (208 209, 210, 211 ) and a plurality of longitudinal grooves (205 206, 207), said transverse (208 209, 210, 211) and longitudinal (205 206, 207) grooves further forming a plurality of intersections between said blocks (201, 202, 203, 204 ), wherein said plurality of intersections comprise wide intersections (212), each wide intersection (212) comprising a respective portion of a radially inner surface of said tread band (2) having a dimension such as to allow an ellipse (213) is inserted there, said ellipse having geometric axes (214, 215) longer than the width of the transverse grooves (208, 209, 210, 211) and the longitudinal grooves (205, 206, 207) forming the wide intersection (212) , at least one of said geometric axes (214, 215) having a length equal to pel. at least 1.5 times the width of both said transverse grooves (208 209, 210, 211) and said longitudinal grooves (205 206, 207) forming said wide intersection (212), and wherein at each intersection is wide (212) a squat shaped protrusion (216) having a width greater than the height is arranged, projecting from said part of the radially inner surface of said tread (2), said protrusion (216) having a volume less than a volume of blocks (201, 202, 203, 204) surrounding said wide intersection (212) and so as to provide said protrusion (216) with a lateral stiffness greater than a lateral stiffness of said surrounding blocks (201, 202, 203, 204 ); said protrusion (216) protruding from said radially inner surface of said tread (2) at a height less than the depth of said wide intersection (212); characterized by the fact that said height is between 25% and 75% of the depth of said wide intersection (212); a base surface (217) of said protuberance (216) has a size of at least equal to 40% of the length of the minor axis (215) of the ellipse (213) inscribed at said broad intersection (212).
    [0002]
    2. Tire according to claim 1, characterized in that said blocks (201, 202, 203, 204) are arranged according to a plurality of circumferential rows (A, B, C, D), axially in relation to the side by side.
    [0003]
    3. Tire according to claim 2, characterized in that said wide intersections (212) are formed between at least one pair of adjacent circumferential rows (A, B, C, D) of the blocks (201, 202, 203, 204), comprising transverse grooves (208 209, 210, 211) alternated in the transverse direction.
    [0004]
    4. Tire according to claim 3, characterized in that said wide intersections (212) are formed between at least two pairs of adjacent circumferential rows (A, B, C, D) of the blocks (201, 202, 203, 204), each pair of circumferential rows (A, B, C, D) having transverse grooves (208 209, 210, 211) alternating in the transverse direction.
    [0005]
    5. Tire according to any one of claims 2 to 4, characterized in that it comprises at least four circumferential rows (A, B, C, D) of blocks (201, 202, 203, 204), axially in relation to the side by side.
    [0006]
    6. Tire according to claim 5, characterized in that said at least four circumferential rows (A, B, C, D) of blocks (201, 202, 203, 204) divide a width of said tread ( 2) in the respective at least four parts with the same width.
    [0007]
    7. Tire according to any one of the preceding claims, characterized in that the shape of said protrusion (216) is frusto-conical.
    [0008]
    8. Tire according to any one of the preceding claims, characterized in that a profile of a base surface (217) of said protrusion (216) is spaced from the walls of said blocks (201, 202, 203, 204) surrounding said wide intersection (212).
    [0009]
    9. Tire according to any one of the preceding claims, characterized in that at least said blocks (201, 202, 203, 204) surrounding said wide intersection (212) comprise an inclined front wall (218).
    [0010]
    10. Tire according to claim 9, characterized in that said inclined front wall (218) comprises at least one step.
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    同族专利:
    公开号 | 公开日
    EP2655094B1|2017-02-15|
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    CN103260904B|2016-03-02|
    RU2013132689A|2015-01-27|
    US9914329B2|2018-03-13|
    WO2012085639A1|2012-06-28|
    US20130263988A1|2013-10-10|
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    BR112013014269A8|2018-07-03|
    EP2655094A1|2013-10-30|
    RU2595728C2|2016-08-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB903389A|1957-09-30|1962-08-15|Pirelli|Improvements in or relating to pneumatic tyres|
    JPS63106110A|1986-10-23|1988-05-11|Bridgestone Corp|Radial tyre for heavy load|
    JPH0220407A|1988-07-09|1990-01-24|Sumitomo Rubber Ind Ltd|Radial tire for heavy duty vehicle|
    FR2643312B1|1989-02-22|1991-07-26|Michelin & Cie|"HEAVYWEIGHT" TIRE TREAD, WITH CENTRAL RIBS WITH INCLINED INCISIONS|
    US5160385A|1989-08-08|1992-11-03|Bridgestone Corporation|Heavy duty pneumatic tires|
    JPH03132403A|1989-10-18|1991-06-05|Bridgestone Corp|Radial tire for heavy load|
    US5198047A|1990-11-14|1993-03-30|The Goodyear Tire & Rubber Company|Winter type tire tread|
    US6176284B1|1996-07-19|2001-01-23|Sumitomo Rubber Industries, Ltd.|Pneumatic tire|
    US6000451A|1996-07-19|1999-12-14|Sumitomo Rubber Industries, Ltd.|Pneumatic tire including at least one projection|
    JP3507634B2|1996-10-01|2004-03-15|住友ゴム工業株式会社|Pneumatic tire|
    EP1237736B1|1999-11-30|2009-08-12|Pirelli Tyre S.p.A.|Tyre for vehicle wheels, particularly for medium and heavy motor vehicles such as lorries and similar|
    US6866076B2|2000-02-07|2005-03-15|Bridgestone Corporation|Tire having longitudinally extending smaller grooves formed in the walls of a groove|
    JP2004058936A|2002-07-31|2004-02-26|Bridgestone Corp|Pneumatic tire|
    JP2005035370A|2003-07-18|2005-02-10|Yokohama Rubber Co Ltd:The|Pneumatic tire|
    KR100754351B1|2005-10-21|2007-08-31|금호타이어 주식회사|Heavy duty pneumatic radial tire|
    DE102006029048A1|2006-06-24|2008-01-03|Continental Aktiengesellschaft|vehicle tires|
    JP4968895B2|2006-09-25|2012-07-04|東洋ゴム工業株式会社|Rough road running pneumatic tire|
    WO2008064703A1|2006-11-30|2008-06-05|Pirelli Tyre S.P.A.|Tire tread comprising blocks with stepped sidewalls|
    JP4525727B2|2007-10-23|2010-08-18|横浜ゴム株式会社|Pneumatic tire|
    JP4996661B2|2009-10-15|2012-08-08|住友ゴム工業株式会社|Pneumatic tire|WO2014083758A1|2012-11-30|2014-06-05|株式会社ブリヂストン|Pneumatic tire|
    CN103223827A|2013-04-27|2013-07-31|风神轮胎股份有限公司|Tire surface pattern for reducing tire noise|
    JP5827669B2|2013-12-04|2015-12-02|住友ゴム工業株式会社|Pneumatic tire|
    FR3018734B1|2014-03-18|2017-08-18|Michelin & Cie|TIRE FOR A VEHICLE OF CIVIL ENGINEER WITH IMPROVED ENDURANCE|
    CN103935192A|2014-04-17|2014-07-23|江苏通用科技股份有限公司|Multifunctional tire pattern structure|
    US9878585B2|2014-05-29|2018-01-30|Sumitomo Rubber Industries Ltd.|Pneumatic tire|
    FR3026347B1|2014-09-30|2018-03-23|Compagnie Generale Des Etablissements Michelin|TIRE COMPRISING A TREAD COMPRISING A PROTUBERANCE ELEMENT IN A TRANSVERSE GROOVE|
    JP1539609S|2015-06-10|2015-12-07|
    USD782961S1|2015-06-10|2017-04-04|Bridgestone Corporation|Tread portion of an automobile tire|
    JP6623764B2|2016-01-06|2019-12-25|住友ゴム工業株式会社|Pneumatic tire|
    USD781216S1|2016-01-08|2017-03-14|Sumitomo Rubber Industries, Ltd.|Tire for automobile|
    USD781215S1|2016-01-08|2017-03-14|Sumitomo Rubber Industries, Ltd.|Tire for automobile|
    USD780673S1|2016-01-08|2017-03-07|Sumitomo Rubber Industries, Ltd.|Tire for automobile|
    KR102023716B1|2016-03-03|2019-09-20|주식회사 엘지화학|Battery system for vehicle|
    FR3050402A1|2016-04-22|2017-10-27|Michelin & Cie|TIRE TREAD COMPRISING DECOUPURES OF DIFFERENT DEPTHS|
    DE102016213702A1|2016-07-26|2018-02-01|Continental Reifen Deutschland Gmbh|vehicle tires|
    USD796426S1|2016-08-25|2017-09-05|Shandong New Continent Tire Co., Ltd|Tire|
    USD815024S1|2016-09-16|2018-04-10|Compagnie Generale Des Etablissements Michelin|Retread band|
    US11007821B2|2017-03-30|2021-05-18|The Yokohama Rubber Co., Ltd.|Pneumatic tire|
    USD913205S1|2018-07-25|2021-03-16|Hankook Tire Co., Ltd.|Tire tread|
    法律状态:
    2018-12-18| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-10-01| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-09-01| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|
    2021-05-11| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-07-06| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 19/12/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    2021-10-05| B16C| Correction of notification of the grant [chapter 16.3 patent gazette]|Free format text: REF. RPI 2635 DE 06/07/2021 QUANTO AO INVENTOR (ITEM 72) |
    优先权:
    申请号 | 申请日 | 专利标题
    ITRM20100689|2010-12-23|
    ITRM2010A000689|2010-12-23|
    US201161466669P| true| 2011-03-23|2011-03-23|
    US61/466,669|2011-03-23|
    PCT/IB2011/003072|WO2012085639A1|2010-12-23|2011-12-19|Tyre for heavy load vehicle wheels|
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