Pneumatic tire

FIELD: transport.

SUBSTANCE: invention relates to tread pattern of tire designed to be used on dry road, ice- and snow-covered roads. Proposed tire comprises unidirectional tread pattern including right and left lengthwise grooves of the crown and crow rib arranged there between. Crown rib has first and second V-like grooves arranged by turns in the tire lengthwise direction. First V-like grooves extend from the left lengthwise groove of the crown. Second V-like grooves extend from the right lengthwise groove of the crown. First and second V-like grooves terminate nearby the rib while their V-like configurations have inflections located, in fact, at tire equator.

EFFECT: stable motion on dry road, ice- and snow-covered roads.

9 cl, 10 dwg, 1 tbl

 

The present invention relates to a pneumatic tire, more particularly to a unidirectional tread pattern, suitable for movement as on a dry road surface and a snowy/icy floor.

It is still widely used technique to improve the driving stability on a dry road surface was to increase, to the extent possible, the ratio of the area of contact with the ground to the total area of the tread, in other words, to increase the rigidity of the tread pattern, namely the total hardness of tread elements, such as blocks, ribs, etc. However, if the ratio increases, because the amount of tread grooves decreases, the shear snow, pressed and compacted into the grooves of the tread decreases, and performance on snowy roads may deteriorate.

If the shear compacted snow high, it can lead to high tractive effort or braking effort, so you can get good adhesion characteristics with snow-covered road surface.

On the other hand, a widely used technique to improve the stability of driving on snowy/icy coating is to increase the total length of the edges of the tread elements, for example, formed by the I lamellas or cuts. This technique is widely used winter tyres, so-called nelipovich tires.

However, if the tread area to provide a large number of blades, the rigidity of the tread elements, such as blocks, reduces, therefore, inevitably deteriorates the driving stability on a dry floor, and the protector is subjected to uneven wear.

Thus, the aim of the present invention is to provide a pneumatic tire with a unidirectional pattern of the projector, which can improve the driving stability on a dry floor, and on snowy/icy floor, and also to improve the resistance to uneven wear when driving on a dry floor.

In accordance with the present invention a pneumatic tire includes:

protector, equipped with a unidirectional tread pattern that includes left and right longitudinal grooves of the crown, located on each side of the equator of the tire and passing continuously in the longitudinal direction of the tire to form between them a continuous in the longitudinal direction of the ribs of the crown,

the edge of the crown, provided with a first V-groove and the second V-shaped grooves arranged alternately in the longitudinal direction of the bus,

each first V-shaped groove extends from its open end on the left longitudinally in the groove of the crown to its closed end, located between the right longitudinal groove of the crown and the equator of the tire,

each second V-shaped groove extends from its open end on the right longitudinal groove of the crown to its closed end positioned between the left longitudinal groove of the crown and the equator of the tire,

each of the first and second V-shaped grooves are made of a primary part, passing from the open end toward the equator of the tire is tilted in one longitudinal direction, corresponding to the intended direction of rotation unidirectional tread pattern, and

the secondary portion extending from the primary portion to a closed end with an inclination in the other longitudinal direction opposite to the direction of rotation, where

the inflection point between the primary part and the secondary part is located essentially on the equator of the tire.

Preferably the angle of inclination of the primary part is from 20 to 40 degrees relative to the longitudinal direction, and the angle between the primary part and the secondary part is from 40 to 80 degrees. At least one of the axial edges of the ribs of the crown is made of straight line segments formed between adjacent in the longitudinal direction of the open ends of the V-shaped grooves, and the straight line is inclined to the equator of the tire in the direction of rotation, so that one longitudinal end of each direct the th segment axially offset from adjacent in the longitudinal direction of the other longitudinal end of one of the neighboring in the longitudinal direction of the straight line segments.

BRIEF DESCRIPTION of DRAWINGS

Figure 1 provides a partial detailed top view of the pneumatic tire in accordance with the present invention, showing a unidirectional tread pattern.

Figure 2 presents the cross-sectional view of the protector along the line A-a in figure 1.

Figure 3 presents an enlarged top view of the edge of the crown.

Figure 4 presents a view of the cross-section of a V-shaped grooves on the Central line of the groove.

Figure 5 presents an enlarged view showing the middle blocks and shoulder ribs.

Figure 6 presents a perspective view, showing the average transverse groove.

Figure 7 presents a view of the cross section of average transverse grooves along the line b-b In Figure 5.

On Fig presents a view of the cross section of average transverse grooves along the line C-C in figure 5.

Figure 9(A) and 9(B) presents the V-shaped grooves used the following comparative tests.

Figure 10 presents a perspective view showing another example of the average transverse grooves used the following comparative tests.

The present invention can be used for radial passenger car tyre, thus, taking the radial tire for passenger cars as an example, embodiments of the present invention the dal is described in more detail, with reference to the accompanying drawings.

Radial tyre, namely the pneumatic tire includes, as is well known in the technique, the protector 2 with the edges of The tread, a pair of spaced apart in the axial direction of the boards, each of which is provided with side ring, a pair of side walls, passing between the edges of The tread and sides, the frame is held between the flanges, and reinforcing protector brickery zone located radially outside the carcass in the tread.

The protector 2 is provided with tread grooves defining a tread pattern. The tread pattern is a unidirectional tread pattern, and planned or intended direction R of rotation of the tire is indicated on the sidewalls of letters and an arrow.

The tread grooves include a pair of passing continuously in the longitudinal direction of the longitudinal grooves 3 of the crown, located on each side of the equator With tires, and a couple of passing continuously in the longitudinal direction of the shoulder axial grooves 4, which are located axially outside of the longitudinal grooves 3 of the crown.

Here and further, if required, based on the assumed direction of rotation of the tire, one of the longitudinal grooves 3, as shown in figure 1 on the right side, namely the right of the observer, is called "the left longitudinal groove 3A of the crown, and accordingly the other groove called "right is rodolniy groove 3B of the crown".

In this embodiment the longitudinal grooves 3 of the crown and shoulder longitudinal grooves 4 are straight grooves, essentially possessing improved characteristics of the drainage and improved characteristic pushing snow.

The annular area between the two longitudinal grooves 3 of the crown forms the only edge 5 of the crown, passing continuously in the longitudinal direction of the tire. More specifically, this circular area, there are no grooves passing through the entire width of the annular section.

Ring sections between the longitudinal grooves 3 of the crown and the shoulder of the longitudinal grooves 4 formed in the form of average 6 blocks located in the same longitudinal row 6R.

The annular areas between the shoulder longitudinal groove 4 and the edges of The tread are formed in the form of shoulder blocks located in the same longitudinal row 7R.

In order to provide the required rigidity of the tread without degrading the characteristics of the drainage and characteristics of pushing snow, the transverse width TD longitudinal grooves 3 of the crown is from 4.0 to 6.0% of the width TW of the tread, and

the transverse width TD shoulder longitudinal groove 4 is from 3.0 to 5.0% of the width TW of the tread.

To facilitate the diversion of water around the equator of the tire, where the ground pressure is a maximum, and further improve harakteristikinaimenovanie, the transverse width TD preferably greater transverse width TD.

Here, the width TW of the tread is the distance along the axis of the tire between the edges of The tread, measured in the normally inflated unloaded state of the tire.

The edges of The projector are axially outer edges of the contact area with the soil in the normally inflated unloaded state.

Normally inflated unloaded state means a state in which the tire is mounted on a standard rim and inflate to normal internal pressure, but do not load standard load.

Normally inflated loaded condition means a condition in which the tire is mounted on a standard rim and inflate to normal internal pressure and load standard load.

Standard rim means of a wheel rim officially adopted for tire standards organizations, i.e. JATMA (Japan and Asia), TRA (North America), ETRTO (Europe), STRO (Scandinavia), etc.

Normal pressure and standard load tires represent the maximum air pressure and the maximum load of the tire, these same organizations in the table, the air pressure/maximum load or in such list. For example, the standard wheel rim is a standard rim" in the JATMA (I have onska Association of manufacturers of automotive tires), "measuring wheel" in the ETRTO (European technical organization rims and tyres), "model bus" in the system TRA (Association for the rims and tires), or the like. Normal internal pressure represents the "maximum air pressure" in the system JATMA, the "inflation pressure" in ETRTO, the maximum pressure specified in the table Within loads of tyres at different pressures of the cold pumping" in TRA, or the like, the Standard load is a "maximum load capacity" in the system JATMA, the "load capacity" in ETRTO, the maximum value indicated in the above table in TRA or the like

In the case of tires for passenger cars, for example, normal pressure and standard load tires uniformly determined by the values of 180 kPa and 88% of the maximum load of the tire, respectively.

Here various sizes, positions, etc. are normally inflated unloaded condition of the tire, unless otherwise noted.

In order to maintain a sufficient volume of the groove and to improve the characteristics of pushing snow depth Ug1 longitudinal grooves 3 of the crown and the depth of the Ug2 shoulder longitudinal groove 4 is preferably not less than 6 mm, more preferably not less than 7 mm, but not more than 10 mm, more preferably not more than 9 mm

The transverse distance W1 from the center line G1 of the width of the longitudinal grooves 3 to the ons to the adjacent edge of The tread is preferably not less than 39%, but not more than 47%, more preferably not more than 43% of the total width TW of the tread.

The lateral distance W2 from the center line G2 of the width of the shoulder longitudinal groove 4 to the adjacent edge of The tread is preferably not less than 19%but not exceeding 27% of the total width TW of the tread.

By setting the distances W1 and W2 in the above ranges, you can optimize the balance of rigidity between the edge 5 of the crown and 6R series medium blocks to improve the driving stability.

As shown in Figure 3, the edge 5 of the crown provided with a first V-shaped grooves 10A and the second V-shaped grooves 10B arranged alternately in the longitudinal direction of the tire.

The first V-shaped groove 10A passes from the left longitudinal groove 3A of the crown towards the right longitudinal groove 3B of the crown and ends in the edge 5 of the crown, while it has an open end 14A, open from the left longitudinal groove 3A of the crown, and the closed end 15A, located between the right longitudinal groove 3B of the crown and the equator With tires.

The second V-groove 10B passes from the right longitudinal grooves 3B of the crown towards the left longitudinal groove 3A of the crown and ends in the edge 5 of the crown, while it has an open end 14B, an outdoor-side right longitudinal grooves 3B of the crown, and the closed end of the 15th century, located between the left longitudinally in the groove 3A of the crown and the equator With tires.

Each V-shaped groove 10 (10A, 10B) is made of the primary part 11 extending from the open end 14 (14A, 14B) to the equator With tires with a slope in the expected direction R of rotation of the tire, and

the secondary part 12 extends from the equator To the bus to the closed end 15 (15A, 15C), with a slope in the direction opposite to the intended direction R of rotation of the tire.

The point of inflection of the V-shape is located essentially on the equator of the tire. In this embodiment, all points of inflection are located exactly on the equator of the tire. However, the point of inflection can be located within a zone centered on the equator With tires having a cross width of 2.0%, preferably of 1.5%, more preferably of 1.0% of the width TW of the tread, from the point of view of homogeneity.

Thus, the edge 5 of the crown, where the ground pressure is highest, boundary element, effective to obtain the adhesion forces increased, and you can increase the shear snow, compacted in the groove, and coupling with icy road surface, and to improve the driving stability on snowy/icy roads. Moreover, the point of inflection of the V shape of the first V-shaped grooves 10A and the second V-shaped grooves 10B are essentially located on the tire equator C, and the first V-shaped groove 10A and the second V-shaped grooves 10B are arranged alternately in the longitudinal direction, Therefore, the rigidity of the ribs 5 of the crown is aligned and prevents uneven wear. Moreover, in the expected direction R of rotation of the tire point of inflection in the first place comes into contact with the ground, unlike other parts, thus, water is diverted from a point of inflection in the longitudinal groove 3 of the crown through the primary part 11 and the characteristic water drainage can be improved.

The transverse distance W3 from the closed end 15 (15A, 15C) to the adjacent longitudinal grooves 3 is preferably not less than 1.0%, more preferably not less than 2.0%but not more than 5.0%, more preferably not more than 4.0% of the total width TW of the tread.

If the transverse distance W3 is too large, the shear snow cannot be obtained and operational characteristics of snow cover is deteriorating. If this distance is too small, the rigidity of the ribs 5 of the crown is reduced and the driving stability is deteriorating.

The angle α1 of the primary part 11 is preferably from 20 to 40 degrees relative to the longitudinal direction. The angle α2 between the primary part 11 and the secondary part 12 is preferably from 40 to 80 degrees.

If the angle α1 and angle α2 too large, so-called tread noise increases. Moreover, the resistance of water flow in the longitudinal groove 3 of the crown increases, and the characteristic water drainage deteriorates. If the angle α1 and angle α2 too small corner plot between the primary part 11 and p is dolinoy groove 3 of the crown loses rigidity and may be uneven wear.

The transverse width TD primary part 11 is preferably not less than 0.5%, more preferably not less than 1.0%but not more than 2.5%, more preferably not more than 2.0% of the total width TW of the tread.

The transverse width TD secondary part 12 is preferably not less than 0.5%, more preferably not less than 1.0%but not more than 2.5%, more preferably not more than 2.0% of the total width TW of the tread.

If the transverse width TD and TD primary part 11 and the secondary part 12 is too large, it is difficult to maintain the rigidity of the ribs 5 of the crown. If the transverse width TD and TD too small, the power shift snow is reduced, and in addition may decrease the drainage of water.

To improve drainage in the direction of the longitudinal groove 3 of the crown, it is preferable that the transverse width TD secondary part 12 is gradually increased toward the equator With the bus from the closed end 15, and a transverse width TD primary part 11 is gradually decreased toward the open end 14 of the equator With tires.

Moreover, it is preferable that the closed end 15 was rounded off with a convexity directed towards the adjacent longitudinal groove 3 of the crown, for example, in the form of a semicircle, as shown in Figure 3. Thus it is possible to prevent the occurrence of cracks on the closed end 15.

Figure 4 shows the depth Ug3 V-shaped grooves 10 along the Central line it is Irene. As shown in this drawing, the depth Ug3 gradually decreases from the open end 14 toward the closed end 15 and, preferably, in the range from the open end 14 to the equator With tires, depth Ug3 is 60% to 80% of the depth Ug1.

Thus it is possible to increase the rigidity of the plot rubber protector between the closed end 15 and a longitudinal groove 3 of the crown and can effectively prevent uneven wear of this section.

In case sizes of tires for passenger cars the depth Ug3 preferably set from 1.5 to 6.0 mm

In respect of each of the side edges 13 of the edges of the crown of each segment 13A, 13B of the side edge 13 between adjacent in the longitudinal direction of the V-shaped grooves 10 is straight and slightly inclined to the equator With the tire in the direction R of the intended rotation of the tire.

Therefore, as shown in Figure 3, at each open end 14 and rear end 16 and the upper end 17 of segments separated by a transverse distance W4.

In other words, the width of the ribs 5 of the crown and the width of the longitudinal grooves 3 crown speed change along the longitudinal direction of the tire.

In the result, they provide a suitable shearing force compacted snow on a snow-covered road surface, and can be improved operational characteristics of snow cover, especially the braking performance.

what if the distance W4 is small, it is difficult to increase the shearing force of the snow. If the distance W4 becomes large, the rigidity of the ribs 5 of the crown decreases. From this point of view, the distance W4 is preferably set not less than 1.0 mm, more preferably not less than 2.0 mm, but not more than 4.0 mm, more preferably not more than 3.0 mm

The total number P of V-shaped grooves 10 on the circumference of the tire is preferably from 29 to 37. If the total number of R is too small, the shearing force of the snow decreases, and performance on a snowy road surface deteriorates. If the total number of R is too large, the ratio of the area of contact with the ground to the total area of the tread is reduced, and the deterioration in the driving stability on a dry floor.

As shown in figure 2, in the cross section of the tire including the axis of rotation of the tire, the longitudinal grooves 3 of the crown have surface 8 of the side walls. The surface 8 of the side walls of the grooves include a sloping portion 8A extending from the surface 2A of the projector in the direction to the bottom B8 grooves with an inclination to the center of the width of the groove at a smaller angle to the surface of the projector, and the main portion 8b extending from a radially inner end of the flat part 8A in the direction to the bottom B8 grooves with an inclination to the center of the width of the groove at a large angle or at a right angle to the tread surface.

Moreover, the shoulder longitudinal groove 4 has a surface to which rnost 9 side walls, including the flat portion 9a and the main part 9b, like the longitudinal groove 3 of the crown.

Moreover, in the case of surfaces of the side walls 9 of the shoulder longitudinal groove 4 in this embodiment, the axially inner surface 9A of the side wall is different from the axially outer surface 9B side wall angle, and the axially inner surface 9A of the side wall includes a sloping portion a and the main part 9b, and the axially outer surface 9B of the side wall includes a sloping portion a and the main part 9b.

As for the surfaces 8 and 9A of the side walls, preferably the angles θ1, θ2 sloping parts 8A, a with the main parts 8b, 9b smaller than the intersection angle θ3 flat part of VA with the main part 9b. For example, the angle θ1 and the angle θ2 is approximately 45 degrees, and the angle θ3 is approximately 60 degrees.

Thus it is possible to reduce the deterioration of driving stability and uneven wear when moving with high velocities. In this regard, the bottom of the groove and the main part are connected in the form of an arch (curved surface).

Around the above-mentioned annular area between the longitudinal groove 3 crown and shoulder longitudinal groove 4 are the average transverse grooves 21 with secondary education 6 blocks located in the same longitudinal row 6R.

In this embodiment of axialen the outer edge of the longitudinal grooves 3 of the crown runs parallel to the longitudinal direction of the tire, and as a result, each average unit 6 provided with the axially inner edge 25, passing directly parallel to the longitudinal direction of the tire. Accordingly, in a direction opposite to the intended direction R of rotation of the tire, the width of the longitudinal grooves 3 of the crown periodically decreases along the longitudinal grooves 3 of the crown.

Therefore compacted snow that falls in the groove 3, is sealed between the side walls of the longitudinal grooves 3 of the crown as the rotation of the tire in the expected direction R of rotation of the tire, and as a result it is possible to improve the characteristic snow grip, especially on a snowy road surface.

On the other hand, the axially outer edge 26 of each average unit 6 facing the shoulder longitudinal groove 4, is inclined axially outward of the tire, in the expected direction R of rotation of the tire, to provide a transverse distance W5 equal to the above transverse distance W4, and thereby to obtain the above preferential effects similar to the effects associated with transverse distance W4. Thus, the width of the shoulder longitudinal groove 4 preferably decreases periodically along the shoulder longitudinal groove 4.

In the case of the axially outer edges 26 of the slope opposite to the slope of the segments 13A, 13B of the side edge 13. Accordingly, in the direction p is otivational the intended direction R of rotation of the tire, compacted snow that falls in the shoulder longitudinal groove 4, is sealed between the side walls of the shoulder longitudinal groove 4, and the result can be improved feature snow grip, especially power braking on snow-covered roads.

As a result, snow-covered road surface, the shear compacted snow acts in both directions of rotation of the tire, and can effectively improve operational performance on a snowy road.

In this embodiment, as shown in Figure 5, the axially outer edge 26 of each middle block 6 is made of two inclined straight line segments 26A and 26C, and the aforementioned transverse distance W5 provide in the middle of the axially external edge 26 between the line segments 26A and 26C.

Segment 26A of each block 6 and the segment 26C adjacent block 6 are on the same line through the middle of the transverse groove 21.

Each of the blocks 6 is provided between the line segments 26A and 26C average non-through groove 27, the open side of the shoulder longitudinal groove 4, thus, on both sides of the middle blind grooves 27 in the longitudinal direction of the tire, the rear end of the 26h segment 26A and the front end 26Bt segment 26C are arranged offset in the axial direction of the tire.

In order to improve operational performance on snow-covered floor, the transverse distance is W5 between the rear end 26h and the front end 26Bt preferably set not less than 1.0 mm, more preferably not less than 2.0 mm, but not more than 4.0 mm, more preferably not more than 3.0 mm

Each secondary transverse groove 21 is inclined to the equator With the tire in the direction R of the intended rotation. The average transverse groove 21 includes a pair of side parts 23 a small width and a Central portion 22 between them, with a larger width than the width of the side parts 23.

If the average transverse groove 21 formed with a larger width along the entire length of the groove, then the shearing force of the snow can be increased. But the rigidity of the middle row 6R blocks becomes insufficient, and, in addition, the tread noise increases.

On the contrary, in this embodiment, it is possible to achieve both rigidity and improved performance on the snowy floor as the average transverse groove 21 is narrow in the lateral parts of the middle blocks 6 in the axial direction of the tire, where the rigidity is relatively low, and wide in the Central part of the middle block 6, where the rigidity is relatively high.

Width TD wide Central part 22 of the groove is preferably not less than 1.0%, more preferably at least 1.5%, but not more than 5.0%, more preferably not more than 4.5% of the total width TW of the tread.

Width TD narrow side parts 23 of the groove is preferably not less than 0.5%, more preferably not less than 1.0%, but the e more than 3.5%, more preferably not more than 3.0% of the total width TW of the tread.

Moreover, the relation TD/TD width TD wide Central part 22 of the groove to the width TD narrow side parts 23 of the groove is preferably from 1.5 to 2.0.

Figure 6 presents a perspective view of part of Figure 5, enclosed in the rectangle S1, showing the average transverse groove 21. As shown in Figure 5 and 6 in the wide part 22 provided with a shallow portion 24 on one side in the longitudinal direction of the tire by a local lifting of the bottom of the groove.

Using a shallow part 24, the rigidity of the middle block 6 at the initial stage of tire life may be increased, and can effectively prevent uneven wear.

In a shallow part 24 value Ug5 rise from the bottom of the groove is gradually increased from the axially inner side portion 23A to the axially outer side portion 23C. In the shallow part 24 is formed in the form of a bevel, as shown in Fig.6. Thus, the contact area with the ground tread 2 gradually increases as the tread wear. Thus, it is possible to avoid sudden changes in operational characteristics of the tires, and the original characteristics of the drainage, removing snow, etc. can be maintained over a long period of time.

7 shows the cross-section of average transverse canask the 21 along the line D-D in figure 5.

The surface 28 of the side wall average transverse groove 21 includes a flat portion 28a extending from the surface 2A of the tread to the bottom B28 grooves with an inclination to the center of the width of the groove at a smaller angle relative to the tread surface, and the main portion 28b extending from a radial-inner end of the flat portion 28a to the bottom B28 grooves with an inclination to the center of the width of the groove at a large angle or at a right angle relative to the surface 2A of the tread.

On the surface 28 of the side wall of the groove, if the angle θ4 of intersection of the sloping portion 28a with the main part 28b is too small, and the width 28k sloping portion 28a in a perpendicular direction relative to the Central line of the width of the groove is too small, it is difficult to increase the rigidity of the middle row of blocks 6R sufficiently.

If the angle θ4 of the intersection and width 28k too large, then the area of contact with the ground is reduced and there is a possibility of deterioration of the characteristics of the grip. From this point of view, it is preferable that the angle θ4 ranged from 30 to 45 degrees, and the width 28k ranged from 0.5 to 1.0 mm

In this embodiment, only one surface 28 of the side wall of the groove from the front side relative to the intended direction R of rotation of the tire provided with a sloping part 28a and the main part 28b. And the surface 28 of the side walls of the grooves on the rear side of the issue is lnany only from the main part 28b.

Around the above-mentioned annular area between the shoulder longitudinal groove 4 and the edge of The tread provided with a shoulder transverse grooves 31 with the formation of the shoulder blocks 7, located in the same longitudinal row 7R.

As shown in Figure 5, each of the shoulder lateral groove 31 provided with a connecting crosspiece 32 rising from the bottom of the groove so that the opposite walls of the grooves are essentially connected to each other or held by this jumper.

In this embodiment the connecting crosspiece 32 passes from the shoulder longitudinal groove 4 to the edge of The tread at a relatively short distance.

As shown in figure 2, the surface 34 of the axially inner ends of the connecting jumper 32 is an inclined surface that is essentially parallel (in this embodiment at the same level) above the main part 9b axially outer surface 9B of the side wall. Also, the surface 34 of the axially outer ends of the connecting jumper 32 is inclined axially outward in the direction of the bottom of the shoulder lateral grooves 31.

On Fig presents the cross-section of the connecting crosspieces 32 along the line e-E in figure 5.

The height of the inter-connector 32 from the bottom V grooves is approximately half the depth of the groove, so that when the wear of the projector to tiget approximately half the depth of the grooves, connecting the jumper 32 appears on the surface of contact with the ground.

In this example, in order to improve the performance on a wet road surface when connecting the jumper 32 on the surface of contact with the ground, connecting the jumper 32 provided with a plate 33 along the Central line of the width of the shoulder lateral grooves 31.

The transverse width TD shoulder transverse grooves 31 is preferably from 1.0 to 4.0% of the total width TW of the tread. If the width TD is too large, the rigidity of the number of 7R shoulder blocks becomes insufficient. If this width is too small, performance on snow-covered surface may deteriorate.

Shoulder lateral groove 31 has a surface 35 of the side wall including a flat portion 35A extending from the surface 2A of the tread to the bottom V grooves with an inclination to the center of the width of the groove at a smaller angle relative to the tread surface, and the main portion 35b extending from a radial-inner end of the flat portion 35A to the bottom V grooves with an inclination to the center of the width of the groove at a large angle or at a right angle relative to the surface 2A of the tread.

If the angle θ5 of intersection of the sloping portion 35A with the main part 35b and width 35k sloping portion 35A is too small, it is difficult to increase the rigidity of the shoulder block 7. On the other hand, if the ve is icine too big the area of contact with the ground increases, and the characteristic adhesion may deteriorate.

From this point of view, the angle θ5 is preferably set between 30 and 45 degrees, and the width 35k preferably set between 0.5 to 1.0 mm

In this embodiment, one surface 35 of the side wall of the groove, located on the rear side relative to the intended direction R of rotation of the tire, with only the main part 35b. However, the other surface 35 of the side wall of the groove, located on the front side, which is subjected to greater shearing force in the creation of great traction, provided with a sloping part 35A and the main part 35b, as explained above.

If the ratio of the area of contact with the ground to the total area of the tread 2 is too small, the driving stability may deteriorate. On the other hand, if this ratio is too large, performance on the snowy floor and smoothness can deteriorate. Thus, the ratio is preferably from 68 to 72%.

Comparative tests

Made radial tires of size 225/45R17 for cars with a tread pattern presented in figure 1, and the technical specifications presented in table 1, and these tires were tested on a driving stability, braking performance on icy pok is the eve ENT, operational characteristics of traffic on a snowy road and the resistance to uneven wear.

All of the test tires had the same specifications except for the parameters presented in table 1, and General specifications for all tyres below.

the sloping part of the average transverse groovesprovided
the flat part connecting the jumper and the lamella in the shoulder lateral grooveprovided
The axially outer edge of the longitudinal grooves of the crownparallel to the tire equator
tread width TW201 mm
the transverse width TD longitudinal grooves of the crown5% TW
the transverse width TD shoulder longitudinal groove4% TW
the transverse width TD primary part of the V-shaped groove1,5% TW
the transverse width TD secondary part of the V-shaped groove1,0% TW
the priest is ecna width TD shoulder transverse grooves 2% TW
depth Ug1 longitudinal grooves of the crown8.2 mm
depth Ug2 shoulder longitudinal groove8.2 mm
depth Ug3 from the open end to the tire equator60% Ug1
the distance W1 longitudinal grooves of the crown43% TW
the distance W2 shoulder longitudinal groove23% TW
the angle θ145 degrees
the angle θ245 degrees
the angle θ360 degree
the angle θ445 degrees
the angle θ545 degrees
the total number R33
width K sloping part0.6 mm
width 35K sloping part0.6 mm

Test driving stability

The test car (front wheel drive Japanese 2000cc with a front engine layout) with the set on all four wheels the same test tires (tire pressure 200 kPa) were tested on dry asphalt on route to test tires, and driver test evaluated the handling, rigidity feel and grip with the road surface as a whole, on the basis of bus Crown adopted for 100. The higher the value, the better the stability of driving.

After driving for a distance of 100 km on a dry road surface, conducted the following tests.

Testing braking performance on icy roads and test performance on a snowy road

The test car (tire pressure 220 kPa) tested on icy roads on the route for testing tyres with a speed of 30 km/h and braked sharply, blocking all four wheels, and measured brake to a complete stop.

In table 1 the values of the inverse of the measured braking distance, represented by indicator based on the value for bus Crown adopted for 100, where the higher the value, the better the braking performance.

In addition, the test vehicle was tested on snow-covered roads on the route for the test tire, and driver test evaluated the handling, rigidity feel and traction in General, on the basis of bus Crown adopted for 100. The higher the value, the better the performance of the movement on the snow-covered floor.

The test for resistance to uneven wear

After driving for a distance of 3000 km on su the WMD asphalt coating, for each of the four test tires in four different positions around the circumference of the tire, measured the difference in wear between the axial edges of the ribs of the crown, and the expected average value of 16 (4×4×1) measured values.

Moreover, we measured the difference in wear between the axially inner and outer edges of the medium blocks on each side of the tire equator, and the expected average value of 32 (4×4×2) measured values.

In table 1 the values of the inverse average values presented in the form of scores, based on this value for bus Crown adopted for 100, where the higher the value, the better the resistance to uneven wear.

Table 1
BusCrownCrownApp.1PRPRPRPRPRPRPRPR
V-groove
ConfigurationFig.9 (A)Fig.9 (C)333333333
the angle α (deg)3030301520404530303030
the angle α (deg)6060603040809060606060
W3/T (%) 1,001,01.01,01,01,02,03,04,53,0
W4 (mm)00000000001,0
The average transverse groove
Tg5/TW (%)2,02,02,02,02,02,02,02,0 2,02,02,0
Tg6/TW (%)2,02,02,02,02,02,02,02,02,02,02,0
Shallow part
Configuration-----------
The shoulder longitudinal groove
W5 (mm)00000000000
The results of the tests
The driving stability10097104103104104103105106107105
Characteristics of braking on
icy roads100102102102102102102102102102102
Specifications movement
snow-covered road100104104101102102101103 103102105
The uneven resistance
wear
The edge of the crown100101103102103103102105105104105
Average blocks100100100100100100100100100100

Continuation of table 1
BusPRProverbs 11PRPRPRPRPRPRPRAve. 19
V-groove
Configuration333333333 3
the angle α (deg.)30303030303030303030
the angle α (deg.)60606060606060606060
W3/TW (%)3,03,03,03,03,03,03,03,03,03,0
W4 (mm)2,02,54,02,52,52,52,52,52,5 2,5
The middle axial groove
Tg5/TW (%)3,03,03,03,03,04,53,03,03,03,0
Tg6/TW (%)2,02,02,02,02,02,02,02,02,02,0
Shallow part
Configuration---Figure 10666666
The shoulder longitudinal groove
W5 (mm)0000001,02,02,54,0
The results of the tests
The driving stability105105102105105103105104104102
Characteristics of braking on
icy roads102102102102102102102102102102
Specifications movement
snow-covered road107107109105106108109110111112
The uneven resistance
wear
The edge of the crown105105105105105105 105105105105
Average blocks100100100102104103104104104104

1. Pneumatic tire including:
protector, equipped with a unidirectional tread pattern that includes left and right longitudinal grooves of the crown, located on each side of the equator of the tire and passing continuously in the longitudinal direction of the tire to form between them a continuous in the longitudinal direction of the ribs of the crown,
the edge of the crown, provided with a first V-groove and the second V-shaped grooves arranged alternately in the longitudinal direction of the tire,
each first V-shaped groove extends from its open end on the left longitudinal groove of the crown to its closed end located between the right longitudinal groove of the crown and the equator of the tire,
each second V-shaped groove extends from its open end on the right longitudinal groove of the crown to its closed end positioned between the left longitudinal what anaway crown and the equator of the tire,
each of the first and second V-shaped grooves are made of a primary part, passing from the open end toward the equator of the tire is tilted in one longitudinal direction, corresponding to the intended direction of rotation unidirectional tread pattern, and
the secondary portion extending from the primary portion to a closed end with an inclination in the other longitudinal direction opposite to the direction of rotation, where
the inflection point between the primary part and the secondary part is located essentially on the equator of the tire.

2. Pneumatic tire according to claim 1, in which
the angle of the primary part is from 20 to 40 degrees relative to the longitudinal direction, and
the angle between the primary part and the secondary part is from 40 to 80 degrees.

3. Pneumatic tire according to claim 1, in which
at least one of the axial edges of the ribs of the crown is made of straight line segments formed between adjacent in the longitudinal direction of the open ends of the V-shaped grooves, and
the straight line is inclined to the equator of the tire in the direction of rotation, so that one longitudinal end of each straight section and axially shifted relative to adjacent in the longitudinal direction of the other longitudinal end of one of the neighboring in the longitudinal direction of the straight line segments.

4. Pneumatic tire according to claim 3, in which
and silny shift between the said one longitudinal end and the other longitudinal end is from 1.0 to 4.0 mm

5. Pneumatic tire according to claims 1, 2, 3 or 4, in which
each of the longitudinal grooves of the crown contains the axially external edge, passing directly parallel to the longitudinal direction of the bus.

6. Pneumatic tire according to claims 1, 2, 3 or 4, in which
the protector is equipped with passing continuously in the longitudinal direction of the shoulder longitudinal grooves arranged axially outer side of each of the longitudinal grooves of the crown, and
the average transverse grooves extending from the shoulder longitudinal groove to the longitudinal groove of the crown with an inclination relative to the direction of rotation to form the rows arranged in the longitudinal direction of the medium blocks, and
each secondary transverse groove includes a wide Central portion with a large width and a pair of side parts located on each side of a wide Central portion and having a narrower width than the wide Central part.

7. Pneumatic tire according to claim 6, in which
specified the wide Central portion provided with a shallow part, shifted to one of the side walls of the middle lateral grooves, and a deep part, shifted to the other side.

8. Pneumatic tire according to claim 7, in which
in a shallow part of the depth of the groove gradually increases from one side to the other side.

9. Pneumatic tire according to claim 6, in Kotor is th
the axially outer edge of the middle block is inclined axially outward in the direction of rotation.



 

Same patents:

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Tire features tread asymmetric patter wherein ratio of actual area of contact to total area for zone 2o of outer side is larger than that for inner side zone 2i but with minor difference characteristic of water removal for right and left wheel tires. Said tire has tread surface 2 divided by four lengthwise grooves 3 and 4 into central area 5 of contact with soil, mid areas 6,6 of contact with soil and shoulder areas 7,7 of contact with soil. Said mid area 6o and shoulder area 7o in outer side zone 2o are divided by outer mid transverse grooves 8o and outer shoulder transverse grooves 10o into blocks 9o and blocks 11o. Mid transverse grooves 8o are inclined in opposite direction to inclination of shoulder transverse grooves 10o relative to tire axial direction while transverse grooves 8o and 10o are inclined at angle θmo of 5-45° and at angle θso over 0° and not over 40°, respectively.

EFFECT: better stability in rainy and dry weather.

8 cl, 6 dwg, 1 tbl

FIELD: transport.

SUBSTANCE: tread comprises multiple raised elements 10 confined by cutouts. At least one of said raised elements 10 has dents 2 of maximum depth H not larger than tread thickness. This dent is located in major direction confined by the dent track ends on new tread and in minor direction extending in tread depth. Dent 2 has first part 21 and second part 22. Dent first part 21 extends in minor direction between contact side 15 in new state and depth H1 equal to, at least, 40% of maximum depth H while second part 22 extends the first part 21 in tread depth. Note here that said second part 22 extends to depth H2. Dent second part 22 in major direction has at least one first section 221 and one second section 222.

EFFECT: improved performances.

10 cl, 7 dwg

FIELD: transport.

SUBSTANCE: tread 2 has rounded shoulders and is divided by the main lengthwise grooves 3 and crosswise grooves 4 in blocks 5 furnished with pockets 6, each having zigzag part 8. Lengthwise grooves 3 include at least two axially outer lengthwise grooves 3o dividing the tread 2 into shoulders Ysh and crowns Ycr wherein zigzag part 8 of pockets 6sh in shoulders Ysh features larger zigzag amplitude Wsh and larger zigzag pitch Psh that zigzag amplitude Wcr and zigzag pitch Wcr of zigzag part 8 of pockets 6cr in crowns Ycr. Inclination angle θsh of pockets 6sh relative to axial direction is smaller than angle θcr.

EFFECT: improved flotation at dry road at minimum deterioration of performances on snow-covered road.

7 cl, 7 dwg, 1 tbl

Air tire (versions) // 2506171

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern of stud-free tire. One block of air tire has first and second slitted drain grooves. Every said groove extends in tire width direction. Said grooves are regularly spaced apart in tire circumference. First and second said grooves has first parts of slitted rain groove that features linear shape if seen in the plane. The slitted drain groove second part that features zigzag shape if seen in the plane and is connected with slitted drain groove first part. First part of slitted drain groove has two surfaces of slitted and opposed drain groove walls if seen in direction perpendicular to the length of said slitted drain groove. Said first part comprises the ledge arranged on first surface of said walls and recess arranged second surface of said walls to make recess connected with ledge.

EFFECT: better running on ice and snow.

20 cl, 20 dwg, 1 tbl

Pneumatic tire // 2506170

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern of stud-free tire. Proposed tire comprises sets of blocks G composed of polygonal blocks 10 arranged tightly in crown zone 1. Polygonal blocks 10 are confined by grooves 9 including first grooves 9a of W9a width and arranged between polygonal blocks 10 adjoining in tore circular direction. Width W9a of first grooves 9a is larger than width W9b of second grooves 9b located between polygonal blocks 10, adjoining and staggered.

EFFECT: better flotation on ice and snow.

7 cl, 7 dwg, 4 tbl

Pneumatic tire // 2504483

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Proposed tread pattern comprises multiple screw transverse grooves with their open ends communicated with one of two circular grooves and their extremities terminate in tread section confined on sides by circular grooves. Every skew transverse groove extends from its open end in first direction in tire circumferential line. Tread patter includes also narrow grooves with their starting parts located in the midst of appropriate skew transverse grooves. Every narrow groove extends in second direction opposite the first one to terminate at tread section. Curved and straight parts are located between open end and extremity nearby each skew transverse groove. Said extremity relates to groove straight part extending in tire circumferential direction. Closed end of narrow groove is shifted in second direction in circumferential direction relative to extremity of skew transverse groove extending there along in second direction.

EFFECT: optimised tire performances at wet road coat, higher wear resistance.

18 cl, 10 tbl, 7 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to large truck tire tread. Tire has tread 1 with absolutely new running surface 10 with at least one running path 2 confined by sidewalls located opposite each other. This running part 2 opens discretely to running surface 10 by multiple parts 21 opened outward of the tread. Note here that said open parts 21 have two ends 212 extending under running surface by channels 22 having inlets 221, 222 connected with ends 212 of said open parts 21. Said inlets 221, 222 feature mean area S. Tread is made so that every part 21 opened to sunning surface has closer 4 at every its end to close cross-section of channel inlets 221, 222 in motion and keep passage open.

EFFECT: better braking performances.

10 cl, 10 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, particularly, to passenger car tire tread patters. Tire tread has grooves 2 directed in circle to confine sets of raised elements that make two edge rows. Edge rows have multiple transverse grooves of definite depth and confined by opposite walls. Multiple transverse grooves of one end row include at least one support block 5 extending from at least one wall to confine said groove. Every support block 5 has active surface 50 to contact with other surface in contact with soil surface. Tread features preset relationships for the sum of areas of active surfaces 50 at maximum length LM in crosswise direction of virtual convex surface surrounding all active surfaces of transverse groove. Besides, it has at least one fluid flow channel between every support block and groove bottom.

EFFECT: better operating performance on wet roads.

8 cl, 8 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Tread has H-deep grooves exposed at tread surface and confined by material surfaces spaced at least 2 mm apart. Multiple grooves 2 have at least one shaped ledge 6 at, at least one of said opposed surfaces. Said shaped ledge is confined by radially outward and radially inward surfaces. Said radially outward surface is located closer to tread surface 10 than radially inward surface. Inner and outer surfaces cross at points A1, A2 of the ledge distant from each other in groove direction. Note here that every of said surfaces of every ledge, radially inner and outer, features such profile in section parallel with confining surfaces that radially outward surface profile length is larger than that of radially inward surface.

EFFECT: better performances in rainy weather.

5 cl, 6 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, particularly, to tire tread with flexible device to decreased noises related with resonance of air flowing along tire grooves all over tire circumference. Tire tread 1 is made from rubber with Shore hardness of at least 65. Said tread has at least one groove of width W and depth D. Said groove 2 is confined by two opposite tread parts connected by groove bottom 21. tread comprises multiple closing membranes 4 formed in at least one groove 2. Every closing membrane 4 closed groove 2 at, at least, 50% of groove cross-section. Note here that every closing membrane 7 has mean thickness not over 2 mm and can bend at fluid passage. Closing membranes 4 are made of material with Shore hardness of not over 62. Note here that said hardness is smaller than that of the tread.

EFFECT: decreased resonance noises.

8 cl, 7 dwg

Pneumatic tire // 2508996

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Proposed tire comprises multiple circular main grooves extending in tire circumference and multiple running surfaces separated and composed by said circular main grooves in tread zone. Multiple running sections have multiple sipes. At least 90% of sipes located in inner side area represent are 2D sipes and at least 90% of sipes in outer side surface are 3D sipes. Tread zone comprises top and bottom rubber layers. Rubber hardness H1in at -10°C and rubber hardness H2in at 20°C of rubber top layer 151in in inner side area, and hardness H1out at -10°C and hardness H2out at 20°C of rubber top layer 151out in outer side area are related by relationships H1in<H1out and H2in<H2out.

EFFECT: better stability on dry and snowy surface.

18 cl, 9 dwg

Pneumatic tire // 2508995

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Tire tread has circular major grooves extending in tire circumference and contact parts separated and composed on said circular major grooves. Every said central zone contact part and contact parts of right and left shoulder zone has multiple sipes. At least 90% of sipes located in inner side area represent are 2D sipes in central zone and at leas 90% of sipes in outer side surface are 3D sipes in shoulder zone. Every contact parts of right and left shoulder zones has multiple transverse side grooves arranged in definite order in tire circumference. The number N-ce of transverse side grooves in central zone contact part and the number N-sh of transverse side grooves in contact parts of right and left shoulder zones are relates as N-ce>N-sh.

EFFECT: perfected design.

20 cl, 7 dwg

FIELD: transport.

SUBSTANCE: tread comprises multiple raised elements 10 confined by cutouts. At least one of said raised elements 10 has dents 2 of maximum depth H not larger than tread thickness. This dent is located in major direction confined by the dent track ends on new tread and in minor direction extending in tread depth. Dent 2 has first part 21 and second part 22. Dent first part 21 extends in minor direction between contact side 15 in new state and depth H1 equal to, at least, 40% of maximum depth H while second part 22 extends the first part 21 in tread depth. Note here that said second part 22 extends to depth H2. Dent second part 22 in major direction has at least one first section 221 and one second section 222.

EFFECT: improved performances.

10 cl, 7 dwg

FIELD: transport.

SUBSTANCE: tread 2 has rounded shoulders and is divided by the main lengthwise grooves 3 and crosswise grooves 4 in blocks 5 furnished with pockets 6, each having zigzag part 8. Lengthwise grooves 3 include at least two axially outer lengthwise grooves 3o dividing the tread 2 into shoulders Ysh and crowns Ycr wherein zigzag part 8 of pockets 6sh in shoulders Ysh features larger zigzag amplitude Wsh and larger zigzag pitch Psh that zigzag amplitude Wcr and zigzag pitch Wcr of zigzag part 8 of pockets 6cr in crowns Ycr. Inclination angle θsh of pockets 6sh relative to axial direction is smaller than angle θcr.

EFFECT: improved flotation at dry road at minimum deterioration of performances on snow-covered road.

7 cl, 7 dwg, 1 tbl

Air tire (versions) // 2506171

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern of stud-free tire. One block of air tire has first and second slitted drain grooves. Every said groove extends in tire width direction. Said grooves are regularly spaced apart in tire circumference. First and second said grooves has first parts of slitted rain groove that features linear shape if seen in the plane. The slitted drain groove second part that features zigzag shape if seen in the plane and is connected with slitted drain groove first part. First part of slitted drain groove has two surfaces of slitted and opposed drain groove walls if seen in direction perpendicular to the length of said slitted drain groove. Said first part comprises the ledge arranged on first surface of said walls and recess arranged second surface of said walls to make recess connected with ledge.

EFFECT: better running on ice and snow.

20 cl, 20 dwg, 1 tbl

Pneumatic tire // 2506170

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern of stud-free tire. Proposed tire comprises sets of blocks G composed of polygonal blocks 10 arranged tightly in crown zone 1. Polygonal blocks 10 are confined by grooves 9 including first grooves 9a of W9a width and arranged between polygonal blocks 10 adjoining in tore circular direction. Width W9a of first grooves 9a is larger than width W9b of second grooves 9b located between polygonal blocks 10, adjoining and staggered.

EFFECT: better flotation on ice and snow.

7 cl, 7 dwg, 4 tbl

Pneumatic tire // 2504483

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Proposed tread pattern comprises multiple screw transverse grooves with their open ends communicated with one of two circular grooves and their extremities terminate in tread section confined on sides by circular grooves. Every skew transverse groove extends from its open end in first direction in tire circumferential line. Tread patter includes also narrow grooves with their starting parts located in the midst of appropriate skew transverse grooves. Every narrow groove extends in second direction opposite the first one to terminate at tread section. Curved and straight parts are located between open end and extremity nearby each skew transverse groove. Said extremity relates to groove straight part extending in tire circumferential direction. Closed end of narrow groove is shifted in second direction in circumferential direction relative to extremity of skew transverse groove extending there along in second direction.

EFFECT: optimised tire performances at wet road coat, higher wear resistance.

18 cl, 10 tbl, 7 dwg

Pneumatic tire // 2499680

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern of stud-free tire. Pneumatic tire has cutouts 6 extending over tire width and arranged spaced in direction along tire circumference, at least, in shoulder blocks 5a separated by lengthwise grooves extending in tire circumference and crosswise grooves 3 extending over tire width. Open cutouts 6a ad closed cutouts 6b are arranged in turns while depth of open cutouts 6a is smaller than that of closed cutouts 6b.

EFFECT: better running on icy roads, higher wear resistance.

7 cl, 5 dwg, 1 tbl

FIELD: transport.

SUBSTANCE: invention relates to design of slits in tire tread pattern. Treat layer has treat patter forming annular grooves and crosswise grooves while tread blocks 22 with slits are formed. At least some of said slits 27 in lengthwise direction feature wavy configuration. This allows making at least two main surfaces (272A, 272B) in said slit 27 arranged in line and shifted one relative to the other through preset distance C. Transition zone 272C is located between said main surfaces. Adjacent main surface 272A, 272B incorporated locking elements 28 made up of ledge 281 in one of walls of slit 27 and shaped to truncated cone while opposite wall 271 of said slit has recesses 282 of the same shape. Ledge 281 and recess 282 conjugate when walls 281 of aforesaid slit get pressed together. Invention covers appropriate tire tread and to means used in production of the tire.

EFFECT: improved grip.

9 cl, 11 dwg

Pneumatic tire // 2493972

FIELD: transport.

SUBSTANCE: invention relates to configuration of grooves on wheel winter tire tread. Pneumatic tire comprises blind groove 5 on the surface of contact with road surface and at least: three grooves 4 extending radially from hidden axis 2 extending downward from aforesaid contact surface. Expanded section 6 whereat groove width is locally expanded at, at least, one position in mid section between hidden axis 2 and end section 4z of grooves 4.

EFFECT: better braking on ice.

17 cl, 12 dwg, 1 tbl

Pneumatic tire // 2508996

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, namely, to tread pattern. Proposed tire comprises multiple circular main grooves extending in tire circumference and multiple running surfaces separated and composed by said circular main grooves in tread zone. Multiple running sections have multiple sipes. At least 90% of sipes located in inner side area represent are 2D sipes and at least 90% of sipes in outer side surface are 3D sipes. Tread zone comprises top and bottom rubber layers. Rubber hardness H1in at -10°C and rubber hardness H2in at 20°C of rubber top layer 151in in inner side area, and hardness H1out at -10°C and hardness H2out at 20°C of rubber top layer 151out in outer side area are related by relationships H1in<H1out and H2in<H2out.

EFFECT: better stability on dry and snowy surface.

18 cl, 9 dwg

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