Pneumatic tire with slitted drain grooves. RU patent 2508204.

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

The present invention relates to a pneumatic tyre, suitable as tires, and more specifically to a pneumatic tyre that has a good driving stability on dry road surface, while maintaining the minimum performance on snowy road.

Pneumatic tyres for driving on icy and snowy roads, including, for example, studless, usually provided on the surface of the longitudinal tread grooves, passing in the longitudinal direction of the bus, and transversal grooves, passing in the direction of the intersection with longitudinal grooves, with the formation of blocks, which are additionally provided with zigzag lamellas, as it is known, for example, of JP-A-11-310013 and JP-A-2005-041393. Characteristics on snowy roads (hereinafter referred to as "performance on snow") provide due to the action of shear forces snow columns that are generated in the groove, and the regional effect produced thanks to the edges of the blocks and sipes.

It is known that for good characteristics on the snow preferably increase the volume of grooves, thereby increasing the power shift snow bars, and increase the number of lamellas, thus reinforcing the edge effect.

However, increasing the volume of grooves and increase in the number of lamellas leads to a decrease of block stiffness, thus leading to a deterioration of the stability of driving on a dry road surface (hereinafter referred to as "driving stability on dry coating"). Performance on snow and driving stability on dry coating are the characteristics contradictory, and therefore it is difficult to simultaneously support both features at a high level.

Accordingly, the purpose of the present invention is to provide a pneumatic tyre, suitable for driving on icy and snowy road and, moreover, driving stability on dry coating which improved while maintaining the minimum performance in the snow.

This and other objectives of the present invention will become apparent from further description.

Applicants present invention investigated bus, in particular the amplitude and step zigzag lamellas form. Thus, it was found that (1) if the amplitude and step zigzag large, engages opposite zigzag walls lamellas is stable, and therefore the rigidity of the block is relatively growing, as if the amplitude and step zigzag small, the rigidity of the block is weakened, and (2), as shown in Fig.7, if the protector "and" bus split a pair of axial-external longitudinal main grooves of "b" on the shoulder zone "A1" and a zone of "A2" crown area "A2" crown, having a greater contact area with the ground, has a greater impact on the snowy roads, and shoulder zone "A1", which strongly affects shear force in during movement on the turn, have a greater impact on the characteristics of movement on the turn on a dry road surface. Figure 7 symbol of "f1" is designated contact area with the ground bus at rectilinear motion along a snowy road, but a symbol of the "f2" is designated contact area with the ground of the tyres when turning on a dry road surface. Additionally found that resistance transverse force during movement on the turn and lane change of motion, can be effectively increased while maintaining the effective characteristics to capture the snow and popping snow, which improves driving stability on dry road surface with a minimal characteristics on snowy roads, by placing zigzag lamellas with small amplitude and a small step in the zone of "A2" crown exerting more influence on the movement along a snowy road and placement of zigzag lamellas with the big amplitude and a big step in the shoulder areas A1, providing a greater influence on the characteristics of the movements on the turn on a dry road surface. Thus, the present invention is characterised by the difference in the amplitude of zigzag sipes step zigzag and a corner of an arrangement of sipes in the shoulder area and zone of the crown.

In accordance with the present invention provide the pneumatic tire, including protector, supplied by the main longitudinal grooves running continuously in the longitudinal direction of the bus and including a couple of axial-external longitudinal grooves, lateral grooves, passing in the direction of the intersection with the main longitudinal grooves for the separation of tread blocks, and staves, secured in blocks,

protector has a shoulder zone, each of which includes the edge of contact with the ground tread and has a rounded shape of the shoulder, so that the line profile in the longitudinal section of the tire gives a curve in the form of an arc of a circle with radius of curvature of at least 25 mm,

the pair axial external longitudinal grooves shares the protector to the shoulder area located axially on the outside of the external longitudinal grooves and zone crown, located between the external longitudinal grooves

each of lamellas is part of a zigzag, which is passing in the direction of the length of the slats in the form of a zigzag,

lamellas include slats, located in the shoulder areas, and slats, located in a zone of the crown, where zigzag part blades, located in the shoulder areas, has a greater range of Wsh and bigger step Psh than the amplitude of the Wcr and step Pcr part of the zigzag lamellas, located in the area of the crown and slats, located in the shoulder areas, are inclined at an angle Θsh relative to the axial direction of the bus, which was less than the angle Θr relative to the axial direction of the blades, situated in a zone of the crown.

Preferably, the ratio of the WshA/Vcr ranges from 1.2 to 2.0, and the attitude Psh/Pcr ranges from 1.2 to 3.0. Preferably, angle Θsh is 30 or less, and the angle Θ is from 15 up to 60.

Longitudinal main grooves may additionally include at least one internal longitudinal groove, located in the zone of the crown. In a preferred embodiment of longitudinal main grooves include two internal longitudinal grooves located within the area of the crown, for the division of the zone of the crown on the internal zone of the crown, located between the internal longitudinal grooves, and outer zones of the crown, located between each internal longitudinal groove and each external longitudinal groove, and the direction of the slope of blades, situated in the inner zone of the crown, is opposite to the direction of the tilt of lamellas, located on the external areas of the crown, relative to the axial direction of the bus.

Lamellas with small amplitude and a small step zigzag are used to reduce the rigidity of the blocks, and so the blocks can be deformed during contact with the road surface, improving the characteristics of the capture of snow and popping snow. As such wrought blocks are provided in the zone of the crown, having a large impact on the snowy roads, pneumatic tyre according to the present invention has enough characteristics to capture the snow and popping snow, ensuring the effective improvement of the characteristics of the snow. On the other hand, because the slats, located in the shoulder areas, have a large amplitude and a big step zigzag block stiffness in the shoulder areas is increased, that provides high resistance to lateral force in the course of the movement on the turn or lane change movement, and therefore improved driving stability on dry road surface with improved characteristics on snow thanks to the slat programme with small amplitude and a step in the zone of the crown.

The terms "edge contact with the ground protector" or "edge contact with the ground"used here means of axial-the outer edges of the surface of contact with the ground tread, which comes in contact with the ground (flat surface) at an angle of wheel camber 0 deg, provided that the bus set the standard rim, is pumped to the normal internal pressure and such a bus subject to the normal internal pressure then load the standard load. The term "standard rim", as used here, means the rim, determined for each bus in the system of standardization, which is based tire, and means, for example, "standard rim" in the system JATMA (the Japanese Association of producers of automobile tires), "a model of tires" in the system TRAY (the Association of and ) and "dimensional wheel in the system ETRTO (European technical organization and buses). Also, the term "normal internal pressure"as used here, means the pressure of the air-specific bus in the system of standardization and means, for example, "maximum air pressure in the system JATMA, the maximum values listed in table Limits loads of tyres at different pressures cold pumping system TRA, and "pressure pumping ETRTO, in the case of tyres for passenger cars "normal internal pressure" is 180. Moreover, the term "standard load" means the load specified for each bus in the system of standardization and means, for example, "maximum capacity" in the system JATMA, the maximum amount specified in the table "the Limits of tyre loads at different pressures cold pumping in TRA, and "carrying capacity" ETRTO.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 presents the tread profile line of pneumatic tyre pursuant to this invention of the meridional cross-section tires.

Figure 2 is the expanded view of the tread pattern of a pneumatic tyre in accordance with the present invention.

Figure 3 shows the top, showing a block located in the shoulder area.

Figure 4 shows the top, showing a block located in the outer zone of the crown.

Figure 5 shows the top, showing a block located in the inner zone of the crown.

6 presented enlarged view of demonstrating the lamella, located in the shoulder area.

Figure 7 shows schematically showing the area of contact with the ground when driving on snowy roads and contact area with the ground when driving on the turn on a dry road surface.

The embodiment of the present invention is described below, with links to enclosed drawings.

Figure 1 presents the tread profile line 2 pneumatic tyres 1 in accordance with the present invention of the meridional cross-section tires. As shown in figure 1, a pneumatic tyre 1 in this incarnation has a rounded shape of the shoulder, so that the line profile shoulder SH tyres, including the edge of The contact with the ground tread gives a curve in the form of an arc of a circle with a radius of curvature of 25 mm or more. In the case of tyres with such a rounded shape shoulder area Sho located axially on the outside edges of The contact with the ground, which is the external edge relative to the center of rotation, can come in contact with the ground when shear force acts on the bus when moving bus on the turn. Therefore, the area of contact with the ground can be increased compared with tires having the square shape, shoulder or tapered shoulder, can be provided with high lateral reaction wheels. The rounded shape of the shoulder is important for the manifestation of the effects of the present invention. Figure 1 is a symbol of "With" marked equator bus.

Figure 2 presents an example of the tread pattern is suitable for pneumatic tyres 1 according to the present invention, if applied, as tires for passenger cars. Pneumatic tyre 1 contains protector 2, longitudinal main grooves 3 (3i, 3o), held continuously in the longitudinal direction of the bus, and transverse grooves 4 (4o, 4m, 4C), passing in the direction of the longitudinal restraint main grooves 3, so protector 2 is divided into 5 blocks (5o, 5m, 5P) with the formation of checkerboard pattern.

Longitudinal main grooves 3 include at least a couple of axial-external longitudinal grooves 3o sharing protector 2 on the shoulder zone Ysh, located axially on the outside of the external longitudinal grooves 3o, and zone Ycr crown, located between the outer main longitudinal grooves 3o, 3o.

Longitudinal main grooves 3 may optionally include one or more internal longitudinal grooves located in the zone of Ycr crown. In the incarnation, presented in figure 2, the main longitudinal grooves 3 include four longitudinal grooves, including a couple of internal longitudinal grooves 3i passing on both sides of The equator by bus, and a couple of external longitudinal grooves 3o located axially on the outside from the internal longitudinal grooves 3i. Internal longitudinal grooves 3i located in the area of Ycr crown, dividing zone Ycr crown on the internal zone Ycr1 crown, located between the internal longitudinal grooves 3i 3i, and outer zones Ycr2 crown, located between the internal longitudinal grooves 3i and external longitudinal grooves 3o.

Transverse grooves include Central transverse grooves 4C, located in the inner zone Ycr1 crown and forming a series Central units 5s, placed in a certain order in the longitudinal direction of the bus, medium transverse grooves 4m located in each outer zone Ycr2 crown and forming a number of medium-sized blocks 5m, placed in a certain order in the longitudinal direction of the bus, and transverse grooves 4o located in the shoulder area Ysh and forming a number of external blocks 5o, placed in a certain order in the longitudinal direction of the bus.

Longitudinal main grooves 3) are broad grooves with a width of Wg at least 3 mm and can be in the longitudinal direction in the form of a straight line, in the form of a zigzag, in the form of waves, etc. Straight groove edges, formed the walls of the grooves and tread surface and pass in a straight line in the longitudinal direction, are preferable from the point of view of durability. In terms of performance buoyancy of the water and the formation of shear forces snow bars is most preferable to longitudinal main grooves 3 were straight grooves with a permanent shape of cross section and were held in the longitudinal direction.

Depth Dg groove (not shown) main longitudinal grooves 3 is not limited to a particular way, but when the pneumatic tire according to the present invention are made tire for passenger cars, depth Dg groove is usually from 8.0 to 10.0 mm

Width Wy and depth Dy (not shown) cross grooves 4 of the present invention may be the same width and depth of cross grooves used in traditional tires. In General, the width Wy and depth Dy cross grooves 4 same or less than the width of Wg and depth Dg longitudinal grooves 3.

Lamella or slats 6 formed on the surface of each block 5. Each lamel 6 contains at least a zigzag part 8, passing in the form of a zigzag in the direction of lamellas length and can consist only of the zigzag part 8 or can optionally include the linear part or parts of passing from one or from both ends of the zigzag part 8 in the direction along the length of the slats. Linear part may be slightly curved. The width and depth of lamellas of the present invention may be the same width and depth sipes are used in the traditional tires. In this incarnation the slats 6 have a width of about 0.5 mm and the maximum depth of approximately 4,0 mm

In a pneumatic tyre 1 according to the present invention lamellas 6 include lamellas 6sh, located in the shoulder area Ysh, and lamellas 6cr, located in a zone of Ycr crown different from lamellas 6sh. More specifically, as shown in figure 3-5, demonstrating the external power 5o, the average block 5m and the Central unit 5C, respectively, lamellas 6sh formed on external blocks 5o, and slats 6cr formed on the secondary blocks 5m and Central blocks 5C. In the present invention lamellas 6sh and 6cr are formed so that the zigzag part 8 blades 6sh, located in the shoulder areas Ysh, has a greater range of Wsh and bigger step Psh than the amplitude of the Wcr and step Pcr zigzag part 8 blades 6cr located in the zone Ycr crown, i.e. Wsh>Wcr and Psh>Pcr.

Lamella with small amplitude of zigzag and a small step zigzag (here and hereinafter referred to as "lamella with a small zigzag") serves to reduce the rigidity of the blocks, as gearing opposite zigzag walls of the slats of the surface, and the force of cohesion between the walls of the slats of the weak. As a result of blocks are capable to deformation, when the tread surface comes into contact with the ground, that improves the characteristics of the capture of snow and popping snow. In the present invention performance on snow effectively improved due to the location of zigzag lamellas 6cr in the zone Ycr crown, which has a great influence when driving on snow-covered road. On the other hand, lamel with the big amplitude and a big step zigzag (here and hereinafter referred to as "lamella with great zigzag") serves to increase the rigidity of the block, as gearing opposite walls of lamellas deep or strong, and the force of cohesion between the walls of lamellas large. Therefore, high resistance of transverse force acting in the course of the movement on the turn or lane change movement, to the location of zigzag lamellas 6sh in the shoulder area Ysh, having a large impact on driving stability on dry road surface. Thus, along with the generation of lamellas 6cr with a small zigzag in the zone Ycr crown, driving stability on dry coating can be improved, with improved characteristics in the snow.

If the ratio Wsh / Wcr amplitude Wsh zigzag lamellas 6sh to the amplitude of the Wcr zigzag lamellas 6cr is less than 1.20 and if the ratio Psh/Pcr step Psh zigzag lamellas 6sh to step Pcr zigzag lamellas 6cr is less than 1.20, differences in the size of zigzag is too small, thus the above-mentioned effects can not be achieved to a sufficient extent. On the other hand, if the ratio of the Wsh/Wcr more than 2.0 and if the ratio Psh/Pcr is more than 3.0, adverse effect of lamellas 6cr with a small zigzag, located in the area Ycr crown, on the stability of driving on dry coating and adverse effect of lamellas 6sh with great zigzag, located in the shoulder area Ysh, the performance on snow increases, thus, the above-mentioned effects of the invention cannot be achieved sufficiently. Therefore, it is preferable that the ratio of Wsh/Wcr was at least 1.20 including, in particular, at least of 1.40, and not more than 2.0, in particular, not more than 1.8. Moreover, it is preferable that the attitude Psh/Pcr was at least 1.20 including, in particular, at least of 1.40, and not more than 3.0, in particular, not more than 2.5.

As shown in figure 3-5, lamellas 6 are located in such a way that the angle of the Θsh lamellas 6sh, located in the shoulder area Ysh, relative to the axial direction of the bus less than the angle Θr lamellas 6cr located in the zone Ycr crown, regarding the axial direction. The reason is that to ensure the high resistance of the transverse force when driving on the turn or lane change movement, and thereby improving the stability of driving on dry coating, it is important to increase the rigidity shoulder blocks zones Ysh in the axial direction of the bus. On the other hand, as the angle of inclination Θcr lamellas 6cr located in the zone Ycr crown, relatively more marginal elements in the axial and longitudinal directions of the tires may be increased to improve the adhesion characteristics of the tyre with a route not only on a snowy road, but also on the road with a low resistance tires m in particular on an icy road.

Preferably to achieve such effects to the angle of the Θsh lamellas 6sh was 30 or less. It is also preferable to the angle of the Θr lamellas 6cr ranged from 15 up to 60. If the angle of the Θsh is less than 30 degrees, driving stability on dry coating may decrease. If the angle of the Θcr goes beyond the above range, it becomes difficult to improve adhesion characteristics of the tyre with road with low µ. From this point of view is more preferable to the angle of the Θsh amounted to not more than 20 degrees, and the angle of inclination Θr was at least 20° and no more than 40 degrees.

The term «corners Θsh and Θcr tilt lamellas 6 regarding the axial direction» means the angle of the Central line of the "i" of the amplitude of zigzag shape of zigzag part 8 regarding the axial direction of the bus. In the case when the Central line of "i" zigzag represents a curve, angles Θsh and Θcr tilt determine the angle of the tangent to the curve "i" regarding the axial direction.

In a preferred embodiment, as shown on the drawings, lamellas 6cr, located in a zone of Ycr crown form so that the direction of the slope of lamellas 6cr1 located in the inner zone Ycr1 crown (shown in figure 5), was opposite to the direction of the tilt of lamellas 6cr2 located in the outer zones Ycr crown (shown in figure 4) relative to the axial direction of the bus. More specifically, the slats 6cr1 inclined downwards from the top-left edge to the right edge, and lamellas 6cr2 tilted up from the lower left corner to the upper right edge. From the point of view of the prevention of occurrence of drifting, preferably a difference "Θcr1 - Θcr2" between angle Θcr1 lamellas 6cr1 and angle of the Θcr2 lamellas 6cr2 was 15 degrees or less. Figs.4 and 5 angle Θcr1 about the same as the angle of the Θcr2.

Besides, preferably lamellas 6sh, located in the shoulder area Ysh. arranged so that the direction of the tilt of the Central lines of "i" zigzag zigzag part 8 regarding the axial direction is the same as the direction of tilt relative to the axial direction of the external transverse grooves 4o located in the shoulder area Ysh. In the incarnation, presented in figure 3, the Central line of "i" zigzag lamellas 6sh and external transverse grooves 4o tilted up from the lower left corner to the upper right edge. In particular, in the above example, the center line of "i" zigzag lamellas 6sh and external transverse grooves 4o are approximately parallel to each other, thus you can minimize the reduction of block stiffness. It is also preferred, as shown in Fig.6 enlarged, zigzag part 8 lamellas 6sh has a saw-like form, so that alternate the first party 8A zigzag, overlapping with the centre line of the "i" zigzag under the thumb at an angle of?, and the second party 8b zigzag, overlapping with the centre line of the "i" zigzag at a lower angle a, where the direction of the slope the first party 8A zigzag relatively axial direction opposite to the direction of the slope of the Central lines of "i" zigzag regarding the axial direction, and the direction of the tilt of the second party 8b zigzag regarding the axial direction is the same as the direction of the tilt of the Central lines of "i" zigzag regarding the axial direction. In the incarnation, presented in figure 3, the Central line of "i" zigzag, and the second party 8b zigzag tilted upwards left to right, but the first party 8A zigzag tilted down, left to right. If zigzag part 8 blades 6sh has such form, alignment component axial edge of the first parties 8A zigzag and axial component of the edge of the parties second 8b zigzag and equalization component of the longitudinal edges of the first parties 8A zigzag and component longitudinal edge of the parties second 8b zigzag can be achieved by tilting the Central line of the "i" zigzag relative to the axial direction of the zigzag, in particular, having the Central line of the "i" zigzag and external transverse grooves 4o parallel to each other, thus the marginal effects can be balanced, improve the performance of the rectilinear motion, while maintaining of block stiffness in the shoulder areas Ysh at a high level.

On the other hand, the slats 6cr1 and 6cr2 located in the inner and outer zones Ycr1 and Ycr2, crown are formed so that the Central line of "i" zigzag zigzag part 8 tilted in the direction from the axial bus direction opposite to the direction of the tilt cross grooves 4C and 4m located in internal and external areas Ycr1 and Ycr2 crown. In the incarnation, presented in the drawings, the Central line of "i" zigzag lamellas 6 cr1 in the inner zone Ycr1 crown tilted down, left to right, and transverse grooves 4 in the inner zone Ycr1 crown tilted upwards left to right. Besides, in the outer zone Ycr2 crown Central line "i" zigzag lamellas 6cr2 tilted up from left to right, and transverse grooves 4m inclined downwards from left to right. In particular, it is preferable that the Central line of "i" zigzag lamellas 6cr1 crossed with a transverse grooves 4C angle of at least 30 degrees and Central line "i" zigzag lamellas 6cr2 crossed with a transverse grooves 4m angle of at least 30 degrees. Such arrangement of sipes 6cr1 and 6cr2 gives advantage in regard to the characteristics of the snow, as the block stiffness in the zone Ycr crown can be weakened in a reasonable relationship.

Pneumatic tyre according to the present invention preferably has an asymmetric tread pattern, where figures from both sides of the equator With the tyres are different, as shown in figure 2. Pneumatic tyre to translate, presented in the drawings, has an asymmetric tread pattern, in which the outer half of the 2o tread 2, which is on the outside of the vehicle relative to the equator of The tyre when the tyre is fitted on the vehicle has to do Lo real contact area with the ground of total area more than the ratio Li the actual contact area with the ground to the total area of the inner half 2i tread 2 which is located on the inside of the vehicle relative to the equator tyre if the tyre is fitted on the vehicle. Since the ratio of Lo outer half 2o, which have a big load in the course of the movement at the turn, increased, increasing the rigidity of the drawing, driving stability on dry coating can be further improved, while maintaining outstanding above features in the snow. It is preferable that the attitude Lo outer half 2o amounted to 63,5 to 69.5%, and the ratio of internal Li half 2i ranged from 59,5 to 65.5%. Moreover, in terms of performance on snow, driving stability on dry coating and resistance to uneven wear, it is preferable that the difference between the "Lo-Li" relations between Lo and Li ranged from 2.0 to 5.0%. As is well known, the term "ratio of the actual contact area with the ground and the total area", as used here, means the ratio of the surface area of contact with the ground (the total surface area of units) to the total surface of the tread 2 between both edges those, Those contact with the ground protector (including square of all grooves), namely to the entire area of the tread surface 2 in the state, when all the grooves are filled.

In this incarnation each of cross grooves 4m and 4C, located in the area Ycr1 crown, contains both axial ends plots K crossing, in which the transverse groove intersects with longitudinal slots 3, as shown in figure 4 and 5. Width Wyo each of cross grooves 4m and 4C on external sites To the intersection, located on the outer side of the vehicle when the tyre is fitted on the vehicle, provide less than the width of Wyi each of cross grooves 4m and 4C internal sites Ki crossing located on the inner side of the vehicle when the tyre is fitted on the vehicle. As the width Wyo and Wyi cross grooves 4m and 4C with both axial ends set in the ratio Wyo<Wyi, the rigidity of the figure can be increased towards the exterior of the vehicle, thereby driving stability on dry coating additionally improves, in combination with ensuring the ratio Lo<Li. Preferably width Wy each of cross grooves 4m and 4C increases smoothly and/or stepped from the outside of the parcel To the intersection to the internal site Ki crossing.

While the preferred embodiment of the present invention is described with reference to the drawings, it should be understood that the present invention is not limited only to the data of the incarnation and is subject to various changes and modifications.

The present invention in more detail described and explained by the following examples. It should be understood that the present invention is not limited to these examples.

Studless tires for passenger cars the size 205/55R16 and the main tread pattern presented in figure 1, is produced in accordance with specifications provided in table 1, and experienced the driving stability on dry coating and characteristics on snowy roads. Technical characteristics of tires, except for the amplitude and the pitch of the spiral of lamellas, were essentially common to all tires. The results are presented in table 1.

Test methods are described below.

(1) driving Stability on dry coating

Tires installed on all the wheels of the car, and the car felt at the rate of the tests on dry asphalt road. Driving stability (stability when changing lane when driving on the turn) was estimated on the sensations of the driver. The results are presented in the form of the metric based on the result for the comparative example 1, taken for 100. The more value, the better driving stability tires on dry pavement.

Size rim: 16 x 6,5J

The internal pressure of 200 kPa

Vehicle: passenger car 2000 cc FR

(2) performance on snow

The above test vehicle is tested on a snowy road. Driving stability was assessed by the sensations of the driver. The results are presented in the form of the metric based on the result for the comparative example 1, taken for 100. The more value, the better the performance on snow.

Ms. note 1

Ms. note2

Ms. note 3

Example 1

Example 2

Example 3

Example 4

Example 5

Lamella in the zone of the crown

The amplitude of the Wcr zigzag (mm)

Step Pcr zigzag (mm)

Lamella in the shoulder areas

The amplitude of Wsh zigzag (mm)

Step Psh zigzag (mm)

The Ratio Of Wsh/Wcr

Attitude Psh/Pcr

Driving stability on dry coating

Lane changes

Movement on the turn

Performance on snow

Lane changes

Movement on the turn

1. Pneumatic tyre, including protector, supplied by the main longitudinal grooves running continuously in the longitudinal direction of the bus and including a couple of axial-external longitudinal grooves cross grooves, passing in the direction of the intersection with the main longitudinal grooves for the separation of tread blocks and slats, better-off in the units specified protector has a shoulder zone, each of which includes the edge of contact with the ground tread and has a rounded shape of the shoulder, so that the line profile in the longitudinal section of the tire gives a curve in the form of an arc of a circle with a radius of curvature of at least 25 mm, specified pair of axial-external longitudinal grooves shares the protector to the shoulder area located axially on the outside from the specified external longitudinal grooves and zone crown, located between the specified external longitudinal slots, each of the slats has a zigzag part of which is passing in the direction of the length of the slats in the form of a zigzag, these slats include slats, located in the specified shoulder areas, and slats, located in the specified area of the crown, where the specified zigzag part of each of the slats located in the mentioned shoulder areas, has a greater range of Wsh and bigger step Psh than the amplitude of the Wcr and step Pcr zigzag of each of the slats in a specified area of the crown, and these slats, located in the specified shoulder areas, are inclined at an angle Θsh relative to the axial direction of the bus, which was less than the angle Θr relative to the axial direction of these blades, located in a specified area of the crown.

2. Pneumatic tyre according to claim 1 in which the ratio of Wsh/Wcr specified amplitude Wsh part of the zigzag lamellas located in the mentioned shoulder areas, to the specified amplitude of the Wcr part of the zigzag lamellas located in a specified area of the crown, is from 1.2 to 2.0, and the ratio of Psh / Pcr specified step Psh part of the zigzag lamellas located in the mentioned shoulder areas, to the specified step Pcr fins arranged in a specified zone crown makes from 1.2 to 3.0,

3. Pneumatic tyre according to claim 1 in which the specified angle Θsh lamellas located in the mentioned shoulder areas, is 30 or less, and the specified angle Θr lamellas located in a specified area of the crown, is from 15 up to 60.

4. Pneumatic tyre according to claim 1 in which these longitudinal main grooves additionally include two internal longitudinal grooves located in the specified area of the crown, separating the indicated zone of the crown on the internal zone of the crown, located between the specified internal longitudinal grooves, and outer zones of the crown, located between each of the specified internal longitudinal groove and each of the specified external longitudinal groove, and the direction of the slope of blades, situated in the inner zone of the crown is the opposite of the blades, the facilities in the external areas of the crown, relative to the axial direction of the bus.

5. Pneumatic tyre according to claim 1 in which these slats within the specified shoulder area are formed so that the direction of the tilt of the Central line zigzag part of the zigzag lamellas regarding the axial direction is the same as the direction of tilt relative to the axial direction of transverse grooves, located in a specified shoulder area, and the part has a saw-like form, so that alternate the first party (8A) of the zigzag, overlapping with the Central line (i) of the zigzag under the thumb at an angle of?, and the second party (8b) of the zigzag, overlapping with the Central line (i) of the zigzag at a lower angle a, where the direction of the slope of the first party (8A) of the zigzag relatively axial direction opposite to the direction of the slope of the Central line (i) of the zigzag regarding the axial direction, and the direction of the tilt of the second party (8b) of the zigzag regarding the axial direction is the same as the direction of the slope of the Central line (i) of the zigzag regarding the axial direction.

7. Pneumatic tyre according to claim 1 in which each transverse groove, located in the specified area of the crown, contains both axial ends areas of intersection, where the transverse groove intersect with the specified longitudinal grooves, and width Wyo each specified longitudinal grooves on the outer section of the intersection, located from the external side of the vehicle when the tyre is fitted on the vehicle, less than the width of Wyi each specified transverse grooves on the domestic leg crossing, located from the inner side the vehicle when the tyre is fitted on the vehicle.