TW201350365A - Tyre tread for a two-wheel vehicle - Google Patents

Abstract

Tread for a tyre for a two-wheel vehicle improving grip when running on a usage surface liable to become slippery; this tread comprising blocks (1, 2, 3) separated from one another by grooves (4), each block comprising a contact face (10, 20, 30) intended to come into contact with the usage surface as the tyre is running and lateral faces intersecting the contact face to form edge corners delimiting a contour of the contact face having a geometric shape with at least three branches, each branch (11, 21, 31) ending in a point (110, 210, 310) the angle of which is at least equal to 20 degrees and at most equal to 90 degrees, the branches (11, 21, 31) of each block (1, 2, 3), considered two by two, between them determining setback parts (12, 22, 32), each block (1, 2, 3) being provided with slits (111, 112, 113; 211, 212, 213; 311, 312, 313) terminating at one of their ends in one of the setbacks formed on the face of the block and at a same location at their other end so as to create elementary patterns comprising at least two points of the contact face, the said elementary patterns of one and the same block interacting by contact with one another as they pass through contact with the usage surface. Furthermore, in at least part of the tread, the blocks (1, 2, 3) have orientations that are angularly offset from one another according to their axial position with respect to the equatorial median plane.

Description

Tire tread for two-wheeled vehicles

The present invention is directed to a tread block or texture formed on a tread of a bicycle tire to provide good, non-sliding contact with the ground. The purpose is especially to improve the contact between the tire and the ground, and more particularly to improve the contact with the slippery ground or the ground that will become slippery, such as colored lines, pebbles, etc. formed on the road surface, especially when the ground is When the liquid gets wet or covers the ice.

The tire of the bicycle includes a tread for contacting the road surface on which the bicycle is riding through a contact area. In this contact area, the material from which the tread is made must be brought into contact with the road surface to eliminate intermediate elements present between the material and the road surface. Reducing the presence of intermediate components can result in a loss of grip on the contact area, which can cause the rider to fall during a turn. In addition, this loss of grip is the most common cause of accidents.

A tire for a two-wheeled vehicle is described in the patent document US Pat. No. 5,377, 734 for use in all-terrain, with a raised element on the tread in the form of a block with branches, between these branches Forming a contraction site. This invention can significantly improve the grip performance of the tread.

Definition: The groove-to-rubber ratio of the tread block is equal to the ratio of the area of the hollow (groove) defined by the block to the total area (contact area of the block and The area of the hollow part). The low groove to rubber ratio represents a large contact area of the block, and the hollow portion between the blocks has a small area.

The equatorial center plane is a plane perpendicular to the axis of rotation through the position of the tire that is furthest away from the axis in the radial direction.

The block is a raised element formed on the tread and defined by a hollow or groove and including a side wall and a contact surface for contacting the road surface. The geometric center of this contact surface is defined as the center of mass or center of gravity of the surface.

The present invention is directed to providing a solution for a tread block on a tread of a bicycle tire that improves the grip between the tire and the road surface, particularly into a slippery road surface.

In this regard, the object of the present invention is a tread block for use on a tread of a bicycle tire that can be slippery when traveling easily due to surface processing or due to the presence of an intermediate foreign object between the use surface and the tread. Improving the grip of the tread when the surface is used on a surface, the tread block comprising a plurality of tread block elements that are independent of each other and in the form of a block separated from each other by the grooves The tire protrudes outward. The blocks include a contact surface for contacting the surface to be used while the tire is running, and a side surface that intersects the contact surface to form a rim angle defining a contact surface profile having a plurality of branches, each branch Both terminate at a point whose angle is at least equal to 20 degrees and at most equal to 90 degrees. In terms of two branches, each of the branches of the body defines a retraction portion, which is A little closer to the geometric center of the contact surface. According to a preferred configuration, the angle of each point is equal to 80 degrees (plus or minus three degrees). Preferably, the contact surface is defined by a contour comprising at least six branches.

In addition, each block is provided with slits or slits which terminate at one of their ends at one of the indentations formed on the surface of the block and at the same end of the other side. Wherein, to form a basic texture comprising at least two points of the contact surface, the basic lines of the same block interact as they contact each other when in contact with the use surface. Additionally, on at least a portion of the tread, the orientation of the blocks is angularly offset from each other based on their axial position relative to the central plane of the equatorial plane.

Therefore, at least some of the points in the block are arranged to form a zero angle with the circumferential direction of the equatorial center plane or near the central plane of the equator, while the other angles increase as the distance from the center plane increases. . Therefore, when turning, the knight of the two-wheeled vehicle will tilt in the direction he wants to turn, so the block that can work on the tread will be the block on the same side of the plane of the equator, which is the farthest away. At the center of the equator. Thus, due to the arrangement according to the invention, the point of the active block will be substantially perpendicular to the outer boundary of the contact block, which may be present for the formation of a pole (especially in rainy weather). It is especially useful to use any water film or to grasp the ground through this point.

Furthermore, the direction of the slits is such that the slits are rotated relative to the equatorial plane by an average angle depending on the position of the block in which the slits are provided.

Preferably, the slits have a depth at least equal to 50% of the height of the block, the height being measured as the height of the side of the block.

The slit can soften each block in the radial direction (ie, the direction of its thickness) at the central portion and cause an increase in the number of rim angles to increase the partial pressure point and provide additional in each slit Drainage.

Preferably, the slits all intersect at the geometric center of the contact surface of each block.

Studies conducted by the Applicant have shown that it is possible to use textures other than the intrinsic properties of the formation and angles described above, as well as to be able to multiply the biting into the slippery intermediate. It has been confirmed that the lines described above are particularly effective when their contact surfaces are inscribed in a new case with a radius of at most 10 mm (mm), and preferably within a circle between 2 and 8 mm. of.

In one embodiment, the tread pattern has a groove to rubber ratio of up to 75%, preferably up to 60%, to promote increased grip contact with the road.

In one embodiment, the two halves of the tread are symmetrical with respect to the equatorial plane.

In one embodiment, within one half of the tread, the slit of the block is rotated in a direction from the block closest to the equatorial plane toward the block on one of the tread edges. On the other half of the tread, the slits are rotated in opposite directions.

In another embodiment, a plurality of block systems having at least one groove along the circumferential direction (i.e., in a direction tangential to a center on the axis of rotation) are disposed on the equatorial center plane. This other form is advantageous because it can improve the steering of the tire, that is, it can improve the tire along The ease with which the straight route advances, especially on the surface that will become slippery.

In a preferred embodiment, the geometric center of the block on either side of the equatorial center plane is disposed on an oblique line that is symmetric with respect to the equatorial plane. The meaning of setting along the oblique line means that the geometric center of the block is located on the oblique line.

Preferably, the angle of the oblique line along the circumferential direction of the block geometric center is at least equal to 20 degrees and at most equal to 45 degrees. Even better, this angle is equal to 30 degrees with respect to the circumferential direction. The angle of these lines is equal to the angle between the imaginary plane intersecting the tread surface and the plane of the equatorial center, which traverses the geometric center of the block.

In accordance with another advantageous alternative form of the invention, the blocks are disposed in opposing orientation such that at least one point in the body can engage within a constriction of the block adjacent the oblique line. The abutment of a block along an oblique line to another block means that the geometric centers of the two blocks are located at or substantially above the oblique line and define the same hollow or the same groove therebetween.

Engaging a point in a body within a constriction of an adjacent block means that the point is at least partially positioned inside a circle that is tangential to the contact surface of the adjacent block. This configuration can be used with the advantages of any of the alternatives presented herein.

In another advantageous alternative form, the side wall of the block is disposed to be inclined with respect to the contact surface of the block for the purpose of allowing the tread to be more easily contacted with the use surface when passing the intermediate material. The contact pressure at the edge of the contact surface can be optimally adjusted. These side walls can be draped Straight or not perpendicular to the contact surface.

Each point of the block will gradually collapse under load, making it easier to force the water film present on the surface to be used in rainy weather to sever, from which it spreads toward the center of the block. In addition, since the edge of each rim is not completely parallel to the surface of the ground when the block is in contact with the ground, load concentration occurs at the bite point, which makes it easier to cut the water film. Therefore, the dry contact thus established can cause a significant increase in grip, especially since the point of the block is closely attached to the rough portion of the ground or a hole in the ground which would cause a rough portion on the ground. The same grip enhancing mechanism is also produced when the tire is driven in dry weather, for example on a use surface having an intermediate solid object having its own powder properties.

The invention also relates to a tire for a two-wheeled vehicle, or even an inner tube, which uses a tread according to one of the alternative forms described above.

Other features and advantages of the present invention will become apparent from the following description of the <RTIgt;

All of the various forms illustrated with the support of Figures 1 through 3 show a plurality of block inclusions comprising six branches. Of course, these different forms can be easily applied to blocks having more than six branches by those skilled in the art.

Figure 1 is a partial plan view of a tread in accordance with the present invention. According to this first alternative form, the bread for the two-wheeled vehicle contains the bit in the equator. The heart plane (indicated by line XX' in the plane of the drawing) is a plurality of blocks 1, 2, 3 shaped on two sides and having a regular six-branch star shape, which define a plurality of grooves 4. Each of the blocks 1, 2, 3 comprises a contact surface 10, 20, 30, respectively forming a tread surface of the tread, the tread surface being for use on a surface on which the tire provided with the tread is driven For contact. Further, each of the bodies includes a side wall that intersects the contact surface at a rim angle, and the side walls in this example are perpendicular to the contact surface. The rim of the same block defines the contact surface as a six-branch star geometry. The block 1 is closer in the axial direction than the other blocks 2, 3 to the equatorial center plane indicated by the line XX' in Fig. 1. The block 2 is situated between the block 1 and the block 3 in the axial direction, while the latter is closest to the outside in the axial direction. The axial direction refers to a direction extending perpendicular to the direction XX', which corresponds to the direction parallel to the axis of rotation of the tire.

For each block 1, 2, 3, each of their branches 11, 21, 31 extends from the geometric center C1, C2, C3 of the star shape to the end of points 110, 210, 310, respectively. Each point 110, 210, 310 constitutes an angle equal to 60 degrees in this example. Between the two points of the same block 1, 2, 3, they each have a constriction 12, 22, 32 with an angle equal to 120 degrees.

Each block 1, 2, 3 is inscribed in a circle having a radius of less than 10 mm and passing through the end of the point (circle R is shown in dashed lines). Of course, each of the blocks 1, 2, 3 may vary depending on the axial position in question as desired, and remain within the scope of the present invention.

In addition, each block 1 is provided with three slits having a narrow width. 111, 112, 113, all of which intersect at one end of the geometric center of the contact surface of the block 1 and end at the other end with the end of the contraction, in two ways When you consider it, you will form a 120 degree angle between them. By narrow width it is meant herein that the slits are at least partially closed when the tire is provided with the tread such that each of the blocks has a contact surface without discontinuities. The same applies to each of the blocks 2 provided with the slits 211, 212, 213 and each of the blocks 3 provided with the slits 311, 312, 313. The depth of these slits is greater than 50% of the height of the block, which is measured for the height of the lateral faces of the block.

These slits terminate in the indentations of each block and form the basic lines with the two points of the block. For example, the block 1 can be further divided into three basic lines 121, 122, 123. Each of the basic lines includes a third point, which is formed by slits on each of the basic lines. The basic textures in the same block interact with each other because they are in contact with each other due to the closure of the slits.

Furthermore, the blocks 1, 2, 3 and the slits they have are rotated by an average angle depending on the axial position of the block: the block 1 has two points along the circumferential direction in the example shown. The block 2 which is offset from the block 1 in the axial direction contains two points which are at an angle of 30 degrees with respect to the direction XX' (the circumferential direction of the tire). Similarly, the block 3 has two points which are at an angle of 60 degrees with respect to the direction XX'. All is as if the direction of the same block road is determined by the axial position of the block.

In the example shown in Figure 1, the blocks are placed on either side of the tread such that their geometric centers are along an angle having an absolute value equal to 45 degrees. Lines D, D' are aligned. The manner in which the blocks are placed on each side of the equatorial center plane is symmetrical in terms of the line along which the geometric center of the block is disposed. However, there is a circumferentially offset between the block on the tread side and the block on the other side of the tread.

Accordingly, the present invention is limited to the case where there are three slits in each of the six-branch blocks, and those skilled in the art can increase this amount until it reaches the amount of the retracted portion on each block. However, to avoid excessively reducing the rigidity of each block, the number of slits on each block can be reasonably limited. Slits having alternating ribs on opposite walls may be made to reduce relative movement between the walls as they pass through the contact block.

Figure 2 shows a partial plan view of a tread which also uses the first alternative form of block (1, 2, 3) shown in Figure 1. The difference that can be seen is that it has a lower groove to rubber ratio compared to this first alternative. Specifically, at least one of the plurality of blocks is engaged with the constriction of the block adjacent to an oblique line, and the geometric center of the block is aligned with the inclined line.

This makes it possible to increase the density of the block and to make the tread more effective in holding solid objects such as stones. The so-called engagement with the indentation means that the point at which the point of the body is farthest from the geometric center of the block is the inside of the circle of the point on the block immediately adjacent to the block.

In the illustrated example, the same reference numerals are used to denote the same structural elements as used in Fig. 1. It can be seen that on the inclined line D, the block 2 has a point 210 engaged with the constricted portion 12 of the block 1. The inside, and another point 210', engages within the indented portion 32 of the block 3.

Further, the block 1 has a point 110 with respect to the block 1 on the side of the equatorial center plane XX', and is engaged in the constricted portion 12' of the block 1' located on the other side of the same equatorial plane.

Figure 3 is a partial view of a third alternative form of a tread according to the present invention for placement on a tire of a two-wheeled vehicle having a size of 42-622. Likewise, the same reference numerals as used in the preceding figures are also used herein to represent the same structural elements.

The tread is provided with a plurality of blocks 1, 2, 3 having a contact surface in the form of a six-branch star which, in the entirely new case, can be contained within a circle having a radius of 8.3 mm. The angle of each point is 60 degrees, and the angle of the indentation is 120 degrees.

The height of the block is between 3 and 5 mm. Each block has three slits having a width equal to 0.5 mm and a depth of at least 3 mm, all of which intersect at the geometric center of the surfaces.

In the case of normal use, the tire has a contact block length between 60 and 80 mm and a contact block width between 25 and 35 mm.

Furthermore, the sidewall of each block forms a 10 degree clearance angle with respect to the perpendicular to the contact surface of the block. Therefore, the surface area of each block contact surface increases as the tread wears.

Furthermore, the plurality of blocks each have at least one point engaged within the constriction of the block adjacent along the oblique line.

Finally, this third alternative form shows the presence of an additional block 5, which is aligned along the line XX' of the central plane of the equator, which means that it waits The geometric center is located on this line XX'. These blocks 5 have substantially the same geometry as the block 1 which is axially closest to the equatorial center plane and has two points aligned along the direction XX'. Further, each of these blocks 5 is provided with a groove 50 which is disposed along the circumferential direction, that is, along the direction XX'. Because of the presence of the grooves that form the circumferential edges 51, 52, the ability of the tire to maintain a straight path as it travels along a straight line can be improved.

The invention is of course limited to the examples described and illustrated, and various modifications can be made without departing from the scope of the invention. In particular, the number of dots on each block can be greater than six, and the size of the dots on the same block can be different to make it suitable for the desired performance.

1‧‧‧Block

1’‧‧‧Block

2‧‧‧Block

3‧‧‧ Block

4‧‧‧ trench

5‧‧‧ Block

10‧‧‧Contact surface

11‧‧‧ branch

12‧‧‧ Contraction

12’‧‧‧ Contraction

20‧‧‧Contact surface

21‧‧‧ branch

22‧‧‧ Contraction

30‧‧‧Contact surface

31‧‧‧ branch

32‧‧‧ Contraction

50‧‧‧ trench

51‧‧‧Edge corner

52‧‧‧Edge corner

110‧‧‧ points

111‧‧‧slit

112‧‧‧slit

113‧‧‧slit

121‧‧‧Basic lines

122‧‧‧Basic lines

123‧‧‧Basic lines

210‧‧‧ points

210’‧‧‧ points

211‧‧‧ slit

212‧‧‧slit

213‧‧‧slit

210‧‧‧ points

311‧‧‧Slit

312‧‧‧ slit

313‧‧‧Slit

C1‧‧‧Geometry Center

C2‧‧‧Geometry Center

C3‧‧‧Geometry Center

D‧‧‧ line

D’‧‧‧ line

R‧‧‧ Round

Figure 1 is a plan view of a first alternative form of a tread according to the present invention.

Figure 2 is a plan view of a second alternative form of tread in accordance with the present invention.

Figure 3 is a plan view of a third alternative form of the tread according to the present invention.

1‧‧‧Block

2‧‧‧Block

3‧‧‧ Block

4‧‧‧ trench

10‧‧‧Contact surface

11‧‧‧ branch

12‧‧‧ Contraction

20‧‧‧Contact surface

21‧‧‧ branch

22‧‧‧ Contraction

30‧‧‧Contact surface

31‧‧‧ branch

32‧‧‧ Contraction

110‧‧‧ points

111‧‧‧slit

112‧‧‧slit

113‧‧‧slit

121‧‧‧Basic lines

122‧‧‧Basic lines

123‧‧‧Basic lines

210‧‧‧ points

211‧‧‧ slit

212‧‧‧slit

213‧‧‧slit

310‧‧‧ points

311‧‧‧Slit

312‧‧‧ slit

313‧‧‧Slit

C1‧‧‧Geometry Center

C2‧‧‧Geometry Center

C3‧‧‧Geometry Center

D‧‧‧ line

D’‧‧‧ line

R‧‧‧ Round

Claims (13)

The tread for a two-wheeled vehicle tire can improve grip when traveling on a use surface that is liable to become slippery due to the presence of an intermediate foreign object, the tread comprising: blocks (1, 2, 3), each being The grooves (4) are spaced apart, each block comprising a contact surface (10, 20, 30) for contacting the use surface as the tire travels, and a side surface intersecting the contact surface to define the contact The rim of the surface profile, the geometry of the contact surface having a plurality of branches, each branch (11, 21, 31) terminating at a point (110, 210, 310), the angle being at least equal to 20 degrees and at most equal to At 90 degrees, each point (110, 210, 310) can pass through the intermediate foreign object to establish direct contact with the surface of use, and the branches (11, 21, 31) of each block (1, 2, 3) are Two of the two, which form a retracted portion (12, 22, 32) therebetween, that is, a portion closer to the geometric center (C1, C2, C3) of the contact surface than each of the points, the tire The surface is characterized in that each block (1, 2, 3) comprises a contact surface having at least six branches and each block (1, 2, 3) are respectively provided with slits (111, 112, 113; 211, 212, 213; 311, 312, 313) which terminate at the one end of one end of the block at the one end of the block One of the retracted portions formed thereon, and at the same position at the other end, to constitute a basic texture including at least two points of the contact surface, the basic texture of the same block is passed through The surfaces in contact with each other interact with each other, and on at least a portion of the tread, the orientation of the blocks (1, 2, 3) is based on their axial position relative to the central plane of the equatorial plane. They are angularly offset from each other. As in the tread of claim 1, the slits (111, 112, 113) of one of the bodies (1) all intersect at the geometric center (C1) of the contact surface of the block. The tread of claim 1 wherein the angular offset of the block (1, 2, 3) according to its axial position is equal to or substantially equal to 30 degrees. For example, in the tread of claim 1, each of the blocks (1, 2, 3) is inscribed in a circle (R) having a radius of at most 10 mm. The tread of claim 4, wherein the radius of the circle (R) is at most equal to 8 mm and at least equal to 2 mm. A tread as claimed in claim 1 wherein it has a groove to rubber ratio of at most 75%. The tread of claim 1, wherein the slit of the block is oriented in a direction from a block that is closest to the equatorial plane toward a block on one of the tread edges. Rotating, and on the other half of the tread, the slit rotates in the opposite direction. The tread of claim 1 wherein a plurality of blocks (5) are disposed on a plane of the equatorial center, and the blocks (5) are provided with at least one groove (50) along the circumferential direction. The tread of claim 1 wherein the geometric center of the block (1, 2, 3) on the two sides of the equatorial center plane is an oblique line (D, D') disposed symmetrically with respect to the equatorial plane. on. The tread of claim 1, wherein the oblique line (D, D') of the geometric center of the block is at least equal to 20 degrees and at most equal to 45 degrees with respect to the circumferential direction. . The tread of claim 1, wherein the plurality of blocks (2) have at least one first point (210) engaged with a retraction of the adjacent block (1) on the same inclined line (D) Within the department (12). The tread of any one of claims 1 to 11, wherein the angle of each point is equal to 80 degrees. A bicycle tire comprising a tread as defined in any one of claims 1 to 12.