Tyre with studs for vehicle wheels

Abstract

A stud tire comprises a tread band (2) on which a plurality of blocks (5) and a plurality of studs (9) arranged on at least some of the blocks are defined. A projection (10) is defined on each block (5) on which the stud (9) is arranged, said projection being spaced apart from the stud and extending continuously around the stud (9) over an angular range greater than or equal to 270 DEG. The projection (10) is delimited at opposite sides thereof by an inner channel (20) and an outer channel (30), both of which are continuous.

Description

TECHNICAL FIELD

[0001] The present invention relates to a studded tire for a vehicle wheel. BACKGROUND ART

[0002] A tire generally includes a carcass structure that is formed annularly around a rotation axis and includes at least one carcass ply having end flanges that are joined into respective annular anchoring structures (referred to as bead cores).

[0003] In a radially outer position relative to the carcass structure, a belt structure is provided, which in the case of a tire for a motor vehicle includes at least two radially superposed strips made of rubber-coated fabric, the strips being provided with reinforcing cords, which are generally made of metal and are arranged in each strip parallel to each other but crossing the cords of adjacent strips, preferably symmetrically with respect to the equatorial plane of the tire.

[0004] Preferably, the belt structure further includes, in a radially outer position, at least at the ends of the underlying belt strips, a third layer of fabric or metal cords that are circumferentially arranged (at an angle of 0 degrees). In a tubeless-type tire, there is further a radially inner layer referred to as a "liner" that has an impermeability characteristic in order to ensure the airtightness of the tire itself.

[0005] In a radially outer position relative to the belt structure, a tread is applied, which is made of an elastomeric material and on which a tread surface intended for contact with the road surface is defined.

[0006] In order to obtain sufficient grip on a wet road surface, the tire has a tread provided with grooves of various configurations and geometries that delimit the portions of the tread intended for contact with the ground (referred to as blocks).

[0007] The main function of the grooves is to be able to drain the water present between the tire surface and the road surface during the mutual contact between the tire surface and the road surface, thereby preventing the tire from partially detaching from the road surface due to the hydrostatic pressure generated by the impact of the water on the advancing tire and causing the vehicle to lose control.

[0008] The overall configuration of the tread defined by the combination of the grooves and the blocks constitutes the tread pattern.

[0009] Generally, the tread pattern is formed by successive and continuous repetition of the same basic module along the entire circumference of the tread.

[0010] In the case of winter tires, small recesses (referred to as "sipe") are formed in the tread blocks of the tread band, and the small recesses extend from the tread surface of the tire towards the inside of the tread blocks. The function of the sipe is to provide additional gripping elements in the case of traveling on a snow-covered surface and to retain a specific amount of snow, thereby improving the grip relative to the road surface.

[0011] In addition, in some winter tires, studs are provided on the tread band, and due to the protruding portions (pins) of the studs from the tread surface, the studs improve the gripping characteristics of the tire on an ice-covered road surface.

[0012] The term "equatorial plane" of a tire refers to the axial central plane perpendicular to the axis of rotation of the tire.

[0013] The term "circumferential" direction refers to the direction that generally points in the direction of rotation of the tire or is inclined at most slightly (at most about 5°) relative to the direction of rotation of the tire.

[0014] The term "axial" direction refers to the direction that is generally parallel to the axis of rotation of the tire or is inclined at most slightly (at most about 5°) relative to the axis of rotation of the tire. The axial direction is usually perpendicular to the circumferential direction.

[0015] The term "tread surface" refers to the radially outer surface portion of the tread band, and when the tire is rolling, the radially outer surface portion is intended to contact the road surface.

[0016] The term "groove" refers to such a recess that is formed in the tread band portion and has a width of greater than or equal to 1.5 mm and a depth of greater than 3 mm.

[0017] The term "tread block" refers to the tread band portion that is bounded by the grooves or the lateral edges of the tread band, and when the tire is rolling, the radially outer surface of the tread band portion is intended to contact the road surface.

[0018] The term "sipe" refers to such a recess that is formed in the tread band portion and has a width of less than 1.5 mm, preferably less than or equal to 1 mm.

[0019] The term "height" of a tread band area (such as a tread block or a part thereof) refers to the radial dimension of the tread band area. Thus, when the distance of the first area from the axis of rotation of the tire is less than that of the second area, the height of the first area is lower than that of the second area.

[0020] The term "channel" shall be understood as a recess formed in the tread block. In other words, a channel is a tread block area, the height of which is lower than the height of the adjacent tread block areas that define the channel. Preferably, the height of the channel is less than the height of the tread surface. Preferably, the channel has a main longitudinal dimension. Preferably, the depth of the channel is less than 3 mm.

[0021] When there is a tread block portion (ridge) within the channel whose height is greater than or equal to the height of the tread block areas adjacent to the channel, the channel is "continuous" or "extends continuously". In other words, when the channel is substantially unobstructed, the channel is continuous. Preferably, the depth of any ridge present within the continuous channel is less than or equal to half of the depth of the channel. Preferably, the depth of any ridge present within the continuous channel is at least 0.2 mm.

[0022] The term "protrusion" refers to a tread block portion that is raised relative to the immediately adjacent tread block areas. In other words, a protrusion is a tread block area whose height is greater than the height of the adjacent tread block areas that define the protrusion. Preferably, the protrusion has a main longitudinal dimension. Preferably, the protrusion is laterally defined by walls that are inclined at an angle greater than 60°, more preferably at approximately 90°, relative to the adjacent tread block areas.

[0023] When the protrusion is uninterrupted, that is, when the height of the protrusion always remains greater than the adjacent tread block areas, the protrusion is "continuous" or "extends continuously".

[0024] The term "width" of a groove, protrusion, channel or a part thereof refers to the dimension parallel to the tread surface and perpendicular to the main longitudinal extension of the groove, protrusion, channel or a part thereof.

[0025] The width of a channel, groove or a part thereof is measured at a depth approximately equal to half of the total depth of the recess or a part thereof.

[0026] If the width of a groove, protrusion or channel varies along its longitudinal extension, the average width is considered, the value of which is obtained by taking the average of different width values after appropriate weighting according to the relative longitudinal ranges. For example, if a groove has a width of 5 mm within 80% of its longitudinal range and a width of 3 mm within the remaining 20% of the range, the average width to be considered is equal to 5x0.8 + 3x0.2 = 4.6 mm.

[0027] When the profile of one or a group of interconnected channels remains confined to the radially outer surface of the tread block, or in other words, when the channel or the group of interconnected channels is not open at the side of the tread block, the one or the group of interconnected channels is "closed".

[0028] The term "tread pattern" refers to the overall structure of the tread band defined by the combination of the grooves and the tread blocks delimited by them.

[0029] Depending on the structure of the tread, a preferred rolling direction can be defined on the tire. In this case, the tire is called an "oriented" type and is constructed to be mounted on a vehicle such that during forward vehicle travel, the tire rotates in this preferred rolling direction.

[0030] The term "footprint area" refers to the part of the tread band that is in instantaneous contact with the road surface during tire rotation. Under actual conditions, the footprint area is a function of different parameters, including the inflation pressure of the tire, the load borne by the tire, the road surface, and driving conditions, but reference values can be defined for these parameters.

[0031] The applicant has observed that during the travel of a studded tire on an ice-covered road surface, the studs can perform the action of eroding the ice, thereby generating powdered ice.

[0032] In particular, the applicant has observed that the powdered ice tends to accumulate in the area adjacent to the studs, but this will reduce the protruding part of the studs that can penetrate into the road surface.

[0033] In fact, the part of the stud protruding from the tread surface can be partially or completely embedded in the powdered ice accumulating around the stud.

[0034] Obviously, this situation makes the gripping effect of the studs on the road surface very inefficient or completely ineffective, and is therefore very undesirable.

[0035] Of course, when the tire slides on the road surface (which may occur in the case of sudden acceleration, hard braking, or rapid steering), the erosion effect on the ice-covered road surface and the consequent generation of powdered ice are more obvious.

[0036] The applicant has observed that a known solution is to form a recess around the stud, which is suitable for collecting a specific amount of powdered ice, with the aim of limiting the influence of the powdered ice accumulating around the stud.

[0037] WO 2018202341, US2019 / 0135047, JP 62723393 describe corresponding solutions for studded tires, in which one or more recesses are formed around the studs, and the recesses are formed in various ways and can collect powdered ice therein.

[0038] However, the applicant has verified that the mere provision of collecting recesses for the powder is not sufficient to solve this problem, and thus it is considered necessary not only to form, around the studs, suitable areas for accumulating the powdered ice eroded by the studs, but also to discharge the powdered ice accumulated in these areas in order to free up space to receive any additional powdered ice subsequently eroded by the studs.

[0039] Thus, the applicant has found that by providing projections around the studs, which projections extend continuously around the studs over a sufficiently large angular range and are laterally delimited by corresponding channels which also extend continuously, the projections are given a high level of deformability, especially during the entry into and exit from the contact area, and the deformability of the projections causes the adjacent channels to undergo contraction and expansion movements, which facilitates the discharge of any powdered ice that may have accumulated therein. Summary of the Invention

[0040] In particular, in a first aspect of the present invention, the invention relates to a studded tyre comprising a tread band on which a plurality of tread blocks are defined and a plurality of studs arranged on at least some of said tread blocks.

[0041] Preferably, a projection is defined on each of said tread blocks on which a stud is provided.

[0042] Preferably, the projection is spaced apart from the stud.

[0043] Preferably, the projection extends around the stud over an angular range greater than or equal to 270°.

[0044] Preferably, the projection extends continuously around the stud.

[0045] Preferably, the projection is delimited on its own opposite sides by an internal channel and an external channel.

[0046] Preferably, the internal channel is continuous.

[0047] Preferably, the external channel is continuous.

[0048] The applicant has verified that, due to this configuration of the area around the stud, any powdered ice eroded by the stud can initially be collected in the two channels delimiting the projection and is subsequently discharged from the channels due to the deformation of the projection, which causes the two channels to contract and expand during the rolling movement of the tyre.

[0049] In fact, due to the special shape of the protrusion, in the case of external stress, for example when entering the grounding area, the protrusion has a high level of deformability so as to bend towards one of the two channels located on its side, thereby reducing the cross-section of said one channel while increasing the cross-section of the other channel.

[0050] When leaving the grounding area, the protrusion not loaded with respect to the vehicle pressure elastically returns to its original configuration together with the two channels adjacent to said protrusion, thereby generating a pulsation which is liable to expel any powdery ice present in the channels.

[0051] This advantageously allows avoiding or at least reducing the accumulation of powdery ice which, once the channels are filled, would be liable to cover the protruding parts of the studs, thereby limiting their efficiency.

[0052] Therefore, when driving on an ice-covered surface, the studs can maintain a higher gripping efficiency and give the studded tyre a better performance level in terms of grip during the traction phases (acceleration and braking) and when cornering.

[0053] In the above aspects, the invention can have at least one of the additional preferred features indicated below.

[0054] In some embodiments, the protrusion is entirely delimited along its entire perimeter by the internal channel, the external channel and two auxiliary channels which connect the internal channel to the external channel.

[0055] In some embodiments, the internal channel, the external channel and the auxiliary channels generally have a closed profile.

[0056] In some embodiments, the protrusion extends between a first end and a second end, the second end being spaced apart from the first end.

[0057] The protrusion thus extends along an open line.

[0058] Preferably, the protrusion extends along a line without any branches.

[0059] The protrusion is thus more easily deformable.

[0060] In some embodiments, the auxiliary channels connect the internal channel to the external channel respectively in the regions of the first end and the second end.

[0061] In some embodiments, the width of each of the auxiliary channels is less than that of the internal channel and the external channel.

[0062] In some embodiments, the protrusion extends around the stud in a symmetric manner with respect to the axis of symmetry passing through the stud.

[0063] Preferably, the internal channel extends around the stud in a symmetric manner with respect to the axis of symmetry.

[0064] Preferably, the external channel extends around the stud in a symmetric manner with respect to the axis of symmetry.

[0065] In some embodiments, the distance between the first end and the second end of the protrusion is between 3 mm and 8 mm, preferably between 4 mm and 6 mm, and more preferably about 5 mm.

[0066] In some embodiments, the internal channel extends into an opening defined between the first end and the second end of the protrusion.

[0067] In this way, a wider area is defined between the two ends of the protrusion for collecting powdered ice. In addition, since the distance between the two ends of the protrusion is relatively small, the area corresponding to this opening is also subject to contraction and expansion caused by the deformation of the protrusion (especially in the areas of its two ends).

[0068] Preferably, the internal channel is connected to the tread surface portion of the tread block through an inclined surface in the area of the opening.

[0069] This promotes the discharge of powdered ice from the opening area.

[0070] In some embodiments, except for the part in the area of the opening, the width of the internal channel is between 0.5 mm and 1.5 mm, preferably about 1 mm.

[0071] Preferably, except for the part in the area of the opening, the internal channel has a substantially constant width.

[0072] In some embodiments, the width of the external channel is between 0.5 mm and 1.5 mm, preferably about 1 mm.

[0073] Preferably, the external channel has a substantially constant width.

[0074] In some embodiments, the protrusion, the internal channel, and the external channel have substantially the same width over at least 80% of their respective longitudinal ranges.

[0075] In some embodiments, the protrusion extends continuously around the stud within an angular range of greater than or equal to 300°.

[0076] In some embodiments, the width of the protrusion is between 0.5 mm and 1.5 mm, preferably about 1 mm.

[0077] Preferably, the protrusion has a substantially constant width along its longitudinal extension.

[0078] In this way, the characteristics of deformability and mechanical strength of the protrusion are optimized.

[0079] In some embodiments, the distance between the protrusion and the stud is variable along the longitudinal extension of the protrusion and is preferably between 1.5 mm and 4 mm.

[0080] In some embodiments, the protrusion is substantially coplanar with a part of the tread surface of the tread block, and the part is adjacent to the outer channel on the side opposite to the protrusion.

[0081] In this way, the protrusion has the same height as the tread surface of the tread block, and thus it contacts the road surface under the same conditions as the tread block. In fact, a protrusion that protrudes excessively from the tread surface may wear prematurely, while a protrusion that is excessively lowered relative to the tread surface may be insufficiently deformed when it moves into the contact area.

[0082] In some embodiments, the protrusion includes a substantially straight first portion. Preferably, the first portion terminates at the first end.

[0083] In some embodiments, the protrusion includes a substantially straight second portion. Preferably, the second portion terminates at the second end.

[0084] In some embodiments, the first portion and the second portion extend from the first end and the second end respectively so as to be separated from each other.

[0085] In some embodiments, the first portion and the second portion are inclined at an angle of 10° to 30°, preferably at an angle of 15° to 20°, with respect to the symmetry axis.

[0086] In some embodiments, the protrusion includes a curved portion extending at an intermediate position between the first end and the second end. Preferably, the curved portion connects the first portion to the second portion.

[0087] Preferably, the curved portion is a circumferential arc, and more preferably, the curved portion is a circumferential arc concentric with the stud.

[0088] In some embodiments, the curved portion extends around the stud within an angular range of 90° to 180°, preferably 120° to 170°.

[0089] In some embodiments, the internal channel is lowered by 0.2 mm to 1.5 mm, preferably approximately 0.5 mm, relative to a portion of the tread surface of the tread block.

[0090] In some embodiments, the external channel is lowered by 0.2 mm to 1.5 mm, preferably approximately 0.5 mm, relative to a portion of the tread surface of the tread block.

[0091] In this way, the internal channel and the external channel define a volume sufficient to collect powdered ice but not significantly reducing the ability to hold the studs within their respective seats.

[0092] In some embodiments, the internal channel is separated from the stud by an island in which a seat for receiving the stud is formed.

[0093] Preferably, the internal channel completely surrounds the island.

[0094] In some embodiments, the island is substantially coplanar with a portion of the tread surface of the tread block, the portion being adjacent to the external channel on a side opposite to the protrusion.

[0095] In some embodiments, the island is substantially coplanar with the protrusion.

[0096] In this way, the island has the same height as the tread surface of the tread block and / or the protrusion.

[0097] In some embodiments, the island is partially bounded by walls parallel to the protrusion.

[0098] Preferably, the island separates the tread block from the internal channel by at least 1 mm.

[0099] Thereby, the ability to hold the studs within their respective seats is retained.

[0100] In some embodiments, a preferred rolling direction is defined on the tread band.

[0101] In some embodiments, the first end and the second end of the protrusion are located downstream of the stud relative to the preferred rolling direction.

[0102] In this way, the opening defined between the ends of the protrusion is also located downstream of the stud, providing a greater volume for the powdered ice generated during a potential braking operation.

[0103] In some embodiments, the symmetry axis of the protrusion is inclined at an angle of 0° to 30° with respect to the circumferential direction, which is defined on the tread band.

[0104] In some embodiments, an equatorial plane is defined on the tread band, and the equatorial plane divides the tread band into a first region of the tread band and a second region of the tread band.

[0105] In some embodiments, for each stud positioned on the tread band, the symmetry axis of the protrusion is inclined such that the first end and the second end point towards the equatorial plane.

[0106] Preferably, for each stud positioned on the first region of the tread band, the symmetry axis of the protrusion is parallel to a first direction, which is inclined at an angle of 0° to 30° with respect to the equatorial plane.

[0107] Preferably, for each stud positioned on the second region of the tread band, the symmetry axis of the protrusion is parallel to a second direction, which is inclined at an angle of 0° to 30° with respect to the equatorial plane.

[0108] Preferably, the first direction and the second direction are symmetric with respect to the equatorial plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] With reference to the accompanying drawings, the features and advantages of the present invention will be better understood from the following detailed description of the preferred embodiments of the present invention, which are illustrated by way of non-limiting examples, wherein:

[0110] Figure 1 is a schematic view of a representative tread band portion of a studded tire for a vehicle wheel constructed in accordance with the present invention;

[0111] Figure 2 is Figure 1 a schematic perspective view, drawn to an enlarged scale, of a portion of a tread block of the tire of

[0112] Figure 3 is Figure 2 a schematic plan view of the tread block of DETAILED DESCRIPTION

[0113] With reference to the accompanying drawings, a studded tire for a vehicle wheel constructed in accordance with the present invention is generally designated by 1.

[0114] The tyre 1 with studs includes a tyre structure and a tread band 2. The tyre structure itself is conventional and not illustrated in the drawings. A tread surface 3 is defined on the tread band. The tread surface is arranged in a radially outer position relative to the tread band 2 and is intended to contact the road surface.

[0115] The tyre 1 has a conventional, generally annular shape that extends around a rotational axis. An axial direction is defined on the tread surface 3. The axial direction is parallel to the rotational axis and an equatorial plane X passes through the axial direction. The equatorial plane is perpendicular to the rotational axis and defines a circumferential direction parallel thereto on the tread surface 3.

[0116] The equatorial plane X divides the tread band 2 into a first tread band region 7 and a second tread band region 8 of equal width. A plurality of grooves are formed in the tread band 2. All of the plurality of grooves are labeled 4 and at least partially define a plurality of tread blocks 5.

[0117] The configuration of the grooves 4 and the tread blocks 5 generally defines the tread pattern of the tyre 1. In the preferred case described herein, the tyre is an oriented tyre, in which a preferred rolling direction of the tyre is defined. The preferred rolling direction is indicated by an arrow F in Figure 1 which.

[0118] Each tread block 5 has a radially outer surface 6 that belongs to the tread surface 3. A plurality of sipes 5a are preferably formed on the radially outer surface 6.

[0119] Some of the tread blocks 5 are provided with one or more studs 9. The studs are configured to provide effective gripping edges for driving on ice-covered road surfaces and are received in corresponding seats 36 according to a conventional method known per se.

[0120] Each stud 9 made of a metallic material includes a base embedded in the tread band 2, a head located radially outside the base, and a gripping extension 9a that extends radially from the head of the stud so as to protrude from the tread surface 3.

[0121] A clearance area is provided around each stud 9 on the tread block 5. The clearance area is substantially circular and centered on the stud 9 (indicated by a dashed line in Figure 1 which). The clearance area has a diameter of approximately 15 to 20 mm. Any sipes 5a are interrupted in the clearance area.

[0122] A protrusion 10 is defined inside the clearance area on the tread block 5. The protrusion is spaced apart from the stud 9 and extends continuously around the stud 9 within an angle range of greater than or equal to 270° (e.g., approximately 310°).

[0123] The protrusion 10 extends along a longitudinal extension line between a first end 11 and a second end 12, and the first end and the second end are spaced apart from each other by approximately 5 mm.

[0124] The protrusion 10 is defined by an internal channel 20 and an external channel 30 on its opposite sides.

[0125] Both the internal channel 20 and the external channel 30 are continuous, and in particular, they have a substantially constant depth with respect to the tread band portion 6, the depth being approximately 0.5 mm and the same for both channels.

[0126] In the regions of the first end 11 and the second end 12, the internal channel 20 and the external channel 30 are connected to each other by an auxiliary channel 21, which has the same depth and width, and the depth and width are smaller with respect to the internal channel 20 and the external channel 30.

[0127] Thus, the protrusion is completely surrounded by the internal channel 20, the external channel 30, and the two auxiliary channels 21 along its entire perimeter.

[0128] Thus, the internal channel 20, the external channel 30, and the two auxiliary channels 21 define a tread block portion having a lower height with respect to the tread surface portion 6 and generally having a closed contour.

[0129] Except for the portions in the regions of the first end 11 and the second end 12, the protrusion 10 has a substantially constant width between 0.5 mm and 1.5 mm, for example, approximately 1 mm, and the protrusion is substantially coplanar with the tread surface portion 6 adjacent to the external channel 30 on the opposite side of the protrusion 10.

[0130] The protrusion 10 extends symmetrically around the stud 9 with respect to a symmetry axis M passing through the stud 9, and includes a first portion 13, a second portion 14, and a curved portion 15. The first portion is substantially straight and terminates at the first end 11, the second portion is also substantially straight and terminates at the second end 12, and the curved portion connects the first portion 13 to the second portion 14.

[0131] The first portion 13 and the second portion 14 extend from the first end 11 and the second end 12 respectively, so as to be separated from each other at an inclination angle of approximately 18° with respect to the symmetry axis M.

[0132] The curved portion 15 is a circumferential arc concentric with the stud 9 (in Figure 3 wherein, the central axis of the stud is defined by the center O of its seat 36), and extends around the stud 9 within an angular range of 90° to 180°, for example, approximately 140°.

[0133] The internal channel 20 is separated from the studs 9 by the island 35, in which a seat 36 for receiving the studs 9 is formed. Further, the island 35 is substantially coplanar with the tread surface portion 6 adjacent to the outer channel 30 on the opposite side of the projection 10.

[0134] Thus, the internal channel 20 completely surrounds the island 35, but remains spaced from the seat 36 by at least 1 mm.

[0135] The portion of the internal channel 20 between the island 35 and the projection 10 has a constant width of 0.5 mm to 1.5 mm, for example approximately 1 mm.

[0136] In the region of the opening 25 defined between the first end 11 and the second end 12 of the projection 10, the internal channel 20 further includes a portion having a greater width.

[0137] Similarly, the outer channel 30 also has a constant width of 0.5 mm to 1.5 mm, for example approximately 1 mm, in the portion between the tread surface portion 6 and the projection 10.

[0138] Thus, it will be noted that the internal channel 20, the outer channel 30, and the projection 10 generally have the same width over the major part (greater than 80%) of their respective longitudinal extents.

[0139] The internal channel 20 in the region of the opening 25, and the end portions of the auxiliary channel 21 and the outer channel 30 in the regions of the first end 11 and the second end 12 of the projection 10 are connected to the tread surface portion 6 of the tread block 5 by the bevels 26.

[0140] Each stud 9 is arranged on a different tread block 5 of the tread band 2 with the corresponding projection 10 and the corresponding internal channel 20 and outer channel 30, such that the first end 11 and the second end 12 of the projection 10 are positioned downstream of the stud 9 with respect to the preferred rolling direction F.

[0141] In particular, in each stud located in the first region 7 of the tread band, the corresponding symmetry axis M of the projection 10 is inclined such that the first end 11 and the second end 12 of the projection 10 point towards the equatorial plane X. Further, this symmetry axis M is generally parallel to the first direction A, which is inclined with respect to the equatorial plane X at an angle of less than 30°, for example approximately 15°.

[0142] Similarly, in each stud positioned in the second zone 8 of the tread band, the respective symmetry axis M of the projection 10 is inclined such that the first end 11 and the second end 12 of the projection 10 point towards the equatorial plane X. Moreover, the symmetry axis M is substantially parallel to a second direction B which is symmetric with respect to the first direction A and is inclined with respect to the equatorial plane X at an angle of less than 30°, for example approximately 15°.

[0143] During vehicle travel, any powdery ice eroded by the studs 9 is initially collected in the internal channels 20, the external channels 30, and the auxiliary channels 21.

[0144] However, when the lug with the stud enters the contact area, the projection 10 deforms due to its specific configuration and thus bends either towards the internal channel 20 or towards the external channel 30, thereby reducing the cross-section of said channel while increasing the cross-section of the other channel.

[0145] When leaving the contact area, the projection 10 tends to elastically return to its original configuration, thereby generating a pulsation which expels the powdery ice accumulated in the channels.

[0146] Thus, the present invention solves the problems posed by the prior art cited above and at the same time offers many other advantages, including making the studded tire 1 aesthetically pleasing and recognizable, especially in the areas marked by the specific structure of the studs 9, the projections 10, and the internal channels 20 and external channels 30.

[0147] Of course, in order to meet specific and possible application requirements, those skilled in the art may make additional modifications and variations to the above invention, and such modifications and variations are still included within the scope of protection defined by the appended claims.

Claims

1. A tire with anti-slip studs, which comprises a tread band (2), on which a plurality of tread blocks (5) are defined and a plurality of anti-slip studs (9) are arranged on at least some of the tread blocks, wherein on each of the tread blocks (5) on which the anti-slip studs are provided, a protrusion (10) is defined, the protrusion is spaced apart from the anti-slip stud and continuously extends around the anti-slip stud within an angular range of greater than or equal to 270°, the protrusion (10) is bounded by an internal channel (20) and an external channel (30) at its opposite sides, and both the internal channel (20) and the external channel (30) are continuous.

2. The tire according to claim 1, wherein, The protrusion (10) extends between a first end (11) and a second end (12), and the second end is spaced apart from the first end (11) by a distance of 3 mm to 8 mm.

3. The tire according to claim 1 or 2, wherein, The protrusion (10) is completely bounded by the internal channel (20), the external channel (30) and two auxiliary channels (21) along its entire perimeter, and the two auxiliary channels connect the internal channel (20) to the external channel (30).

4. The tire according to claim 3, dependent on claim 2, wherein, The auxiliary channels (21) connect the internal channel (20) to the external channel (30) in the regions of the first end (11) and the second end (12) respectively.

5. A tire according to any one of the preceding claims, wherein, The protrusion (10) extends around the anti-slip stud (9) in a symmetric manner with respect to a symmetry axis (M) passing through the anti-slip stud (9).

6. The tire according to any one of the preceding claims, wherein, The protrusion (10) is coplanar with a part of the tread surface (6) of the tread block (5), and this part is adjacent to the external channel (30) on the side opposite to the protrusion (10).

7. The tire according to any one of claims 2 to 6, wherein, The protrusion (10) includes a straight first part (13) and a straight second part (14), and the first part (13) and the second part (14) extend from the first end (11) and the second end (12) respectively so as to be separated from each other.

8. The tire according to claim 7, wherein, The protrusion (10) includes a curved part (15) connecting the first part (13) of the protrusion (10) to the second part (14), and the curved part (15) is a circumferential arc concentric with the anti-slip stud (9).

9. The tire according to any one of the preceding claims, wherein, The internal channel (20) and the external channel (30) are lowered by a height of 0.2 mm to 1.5 mm with respect to a part of the tread surface (6) of the tread block (5).

10. The tire according to any one of the preceding claims, wherein, The internal channel (20) is separated from the anti-slip stud (9) by an island (35), and a seat (36) for receiving the anti-slip stud (9) is formed in the island, and the island (35) is coplanar with a part of the tread surface (6) of the tread block (5), and this part is adjacent to the external channel (30) on the side opposite to the protrusion (10).

11. The tire according to any one of the preceding claims, wherein, The protrusion (10), the internal channel (20) and the external channel (30) have the same width as each other on at least 80% of the parts of their respective longitudinal ranges.

12. The tire according to any one of claims 2 to 11, wherein, A preferred rolling direction (F) is defined on the tread band (2), and the first end (11) and the second end (12) of the projection (10) are positioned downstream of the studs (9) relative to the preferred rolling direction (F).

13. The tire according to any one of claims 5 to 12, wherein, The symmetry axis (M) of the projection (10) is inclined at an angle of 0° to 30° relative to the circumferential direction (X) defined on the tread band (2).

14. The tire according to any one of claims 5 to 13, wherein, An equatorial plane (X) is defined on the tread band (2), the equatorial plane (X) dividing the tread band into a first region (7) of the tread band and a second region (8) of the tread band, and wherein, for each stud (9) positioned on the tread band (2), the symmetry axis (M) of the projection (10) is inclined such that the first end (11) and the second end (12) point towards the equatorial plane (X).

15. The tire according to any one of claims 5 to 14, wherein, For each stud (9) positioned on the first region (7) of the tread band, the symmetry axis (M) of the projection (10) is parallel to a first direction (A), the first direction being inclined at an angle of 0° to 30° relative to the equatorial plane (X), and for each stud (9) positioned on the second region (8) of the tread band, the symmetry axis (M) of the projection (10) is parallel to a second direction (B), the second direction being inclined at an angle of 0° to 30° relative to the equatorial plane (X) and being symmetric to the first direction (A) relative to the equatorial plane (X).

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