CA3029770C

CA3029770C - Vehicle tire

Info

Publication number: CA3029770C
Application number: CA3029770A
Authority: CA
Inventors: Jan Schlittenhard; Christoph Berger; Maik Kotter; Torben SPECHTMEYER
Original assignee: Continental Reifen Deutschland GmbH
Current assignee: Continental Reifen Deutschland GmbH
Priority date: 2016-07-06
Filing date: 2017-05-02
Publication date: 2019-09-17
Anticipated expiration: 2037-05-02
Also published as: EP3481649A1; EP3481649B1; WO2018007039A1; RU2689673C1; CA3029770A1; DE102016212280A1

Abstract

A vehicle tire comprising a tread profile and spikes which are formed with a spike tip with an encircling grip edge having first and second spikes, each having a grip edge, wherein the contour profile of the grip edge of the first spikes has a different form than the contour profile of the grip edge of the second spikes, and in that the spike tip of the first spikes is, with the contour profile of its grip edge, formed asymmetrically with respect to the planes which are perpendicular to its first axis, wherein the length of the projection, formed in the axial direction, of the grip edge of the first spikes is in each case greater than the length of the projection, formed in the axial direction A, of the grip edge of the second spikes.

Description

I
VEHICLE TIRE
TECHNICAL FIELD
The invention relates to a vehicle tire having a tread profile and spikes which are formed with a spike tip with an encircling grip edge, having two axially lateral extent portions of the tread profile, in which in each case only first spikes are formed, and having an axially middle extent portion of the tread profile which is formed between the two lateral extent portions and in which only second spikes are formed, wherein the spike tip of the second spikes is, with the contour profile of its grip edge, formed symmetrically with respect to an axis which is oriented so as to enclose an angle [3 with the circumferential direction U, where 00 p <2ce, wherein the spike tip of the first spikes is, with the contour profile of its grip edge, formed symmetrically with respect to a first axis which is oriented so as to enclose an angle a with the axial direction A, where 0 < a <35 .
BACKGROUND
Vehicle tires are normally formed in each case with identical spikes of uniform design and orientation over their entire extent in an axial direction and in a circumferential direction. Here, said spikes are, as is conventional, optimized for transmitting circumferential forces and thus for traction and braking. The realization of lateral control by means of spikes is secondary in relation thereto. The spikes used for this purpose are normally, in terms of their encircling grip edge, formed symmetrically with respect to the axial direction of the tire. It is also known for all spikes formed in this way to be oriented in the tread profile with an orientation of their axis of symmetry deviating from the axial direction, in order to thus somewhat compensate the disadvantage in terms of lateral control. The traction and braking performance generated by the spikes in the vehicle tire is however reduced as a result.
To achieve optimum grip of tires on ice and snow, it is desirable also in the case of spiked tires to increase both traction and braking performance characteristics and lateral control characteristics to a high level by means of the spikes.

2 Modern tires are commonly formed with a smaller profile depth in the shoulder portion than in their center, in order to thereby make it possible to realize advantages with regard to rolling resistance. For this purpose, in accordance with the varying depth distribution of the profile, the spike length should also be adapted to said depth distribution, and thus be of shorter form in the shoulder than in the middle portion. In the case of the known tires, in which the spikes are designed in identical form, this harbors the risk of confusion during installation, and thus necessitates very great effort in correctly assigning the spikes to the corresponding tire portions during installation. Incorrect positioning of spikes can lead at least to rapid loss of the spikes and thus to restricted usability of the spike effects.
WO 2014/148262 Al has disclosed arranging in each case the same spike with a 1800 rotational offset in a pneumatic vehicle tire. The above-described problems with regard to the conflict of aims between traction and braking performance on the one hand and lateral control on the other hand, and reliable installation in the case of modern tires optimized for rolling resistance, also exist in the case of the tires known from WO 2014/148262 Al.
From EP 11 99 193 Al, it is known for spikes of substantially identical form to be arranged across the entire tire profile width, wherein the spikes are, both in their spike top flange and at their spike tip and at the spike foot, of in each case oval-shaped form, and thus formed in each case with two axes of symmetry in all planes formed perpendicular to the spike longitudinal axis.
It is also known here for the oval of the top flange and of the spike tip in the case of the spikes used at the tire shoulders to be formed so as to be offset in relation to the oval of said spikes of the foot flange by a slightly different angle than in the case of the spikes that are used in the central portion of the tread profile. By means of the rotational offset of the spikes formed in the tire shoulders in relation to the centrally arranged spikes, it is duly possible for lateral forces to be transmitted more effectively. The spikes, formed with a twofold axis of symmetry in terms of their oval shapes, both in the central portion and in the shoulder portion however lead, owing to the twofold symmetry in the shoulder portion, both to a relatively high weight of the spikes in the .. region of the tire shoulder and to the possibility of easy confusion between the two almost identical spike types. The twofold symmetry and the resulting relatively high weight of the spikes

3 in the tire shoulder portion have the result that the spikes in the tire shoulder portion are easily lost under the locally particularly high lateral forces and increased road loading. To avoid the effects caused by high weight, it is therefore possible in the case of said tire to use only spikes with very small forms, in particular of the grip edges. As a result, however, the possibilities for lateral force transmission with good braking and traction force transmission are again restricted.
SUMMARY
The invention is therefore based on the object of making it possible to realize pneumatic vehicle tires with spikes with an improved resolution of the conflict of aims between good lateral control, on the one hand, and good traction and braking performance, on the other hand, while also utilizing the modern tire forms optimized for rolling resistance, and with reliable installation and high durability of the spikes in the tire.
The object is achieved according to the invention by means of the embodiment of a vehicle tire having a tread profile and spikes which are formed with a spike tip with an encircling grip edge.
According to a broad aspect, the invention provides a vehicle tire comprising a tread profile and first and second spikes each formed with a spike tip with an encircling grip edge, having two axially lateral extent portions of the tread profile, wherein in each case only the first spikes are formed, and having an axially middle extent portion of the tread profile which is formed between two lateral extent portions and wherein only the second spikes are formed, wherein the spike tip of the second spikes is, with a contour profile of the encircling grip edge of the second spikes, formed symmetrically with respect to a first axis which is oriented so as to enclose an angle 13 with a circumferential direction of the tire, wherein 0 < 13 <200, wherein the spike tip of the first spikes is, with a contour profile of the encircling grip edge of the first spikes, formed symmetrically with respect to a first axis which is oriented so as to enclose an angle a with an axial direction of the tire, wherein 0 < a <35 , wherein the contour profile of the encircling grip edge of the first spikes has a different form than the contour profile of the encircling grip edge of the second spikes, and wherein the spike tip of the first spikes is, with the contour profile of the grip edge of the first spikes, formed in each case asymmetrically with respect to planes that are perpendicular to the first axis, wherein a length of a projection, formed in the axial direction, of

4 the encircling grip edge of the first spikes is in each case greater than a length of a projection, formed in the axial direction, of the encircling grip edge of the second spikes.
According to embodiments of the invention, it is made possible for the tire to be formed, in the .. axially outer extent portions of a tread profile that are particularly important for the transmission of lateral forces, with spikes optimized for the transmission of lateral forces, and in the middle extent portion that is particularly important for traction and braking, with spikes optimized for the transmission of braking and traction forces. The embodiment of the first spikes with their grip edge profile with only one axis of symmetry makes it possible for grip edges important and particularly effective for the transmission of lateral forces to be provided specifically in the shoulder region. Here, the different form of the encircling grip edges of the first and second spikes permits a reliable, easy distinction between the spikes, whereby installation can be easily performed in a confusion-free manner. By means of the embodiment, it is thus possible even in the case of modern, rolling-resistance-optimized tires for the respectively required spikes to be easily, securely and reliably installed, whereby the use of spikes in the case of low-rolling-resistance modern tires can be made possible in a more reliable manner.
In one embodiment, the width, measured perpendicular to the first axis (m) of the grip edge of the first spike, of the surface enclosed by the contour profile of the grip edge increases along the extent of the first axis (m) toward the side pointing away from the middle extent portion of the tread profile. More specifically, the width of the surface enclosed by the contour profile of the grip edge may increase in continuous fashion along the extent of the first axis. This permits a further improvement in the transmission of lateral forces through the additional optimization of the grip edges in the region of the tire shoulders.
In one embodiment, the contour profile of the grip edge of the first spikes has in each case one rectilinear extent portion to both sides of the first axis, wherein the rectilinear extent portions intersect, at least in their elongation on that side of the grip edge which points toward the middle extent portion of the tread profile, in the first axis, and proceeding from said intersection point run in V-shaped fashion, enclosing an angle, along the extent of the first axis toward the side pointing away from the middle extent portion of the tread profile as far as their extent end,

5 wherein the two extent ends are connected to one another by a third extent portion, extending substantially perpendicular to the first axis, of the grip edge. The contour profile permits a particularly material-saving and weight-saving embodiment, which is thus gentle on the road and provides security against loss, of the spikes used in the shoulder region, and at the same time nevertheless a large grip edge length, which is particularly important specifically in the shoulder region and is effective for the transmission of lateral forces, specifically toward the axial outer side of the tire.
In one embodiment, the third extent portion is formed so as to extend in rectilinear or concavely curved fashion. The rectilinear form permits a particularly simple design of the tool for the production of the spike pins. The concave embodiment permits a further weight reduction of the spike pin, which, depending on the desired requirement profile, can be converted into reduced road wear as a result of lower weight or, with unchanged road wear, into a lengthening of the third extent portion, and thus into increased lateral control, by material redistribution.
In one embodiment, the first and/or the second spikes are composed in each case of a spike body and a spike pin, in which, in the spike pin, the spike tip, and in which the spike body is formed from a foot flange, a middle portion and a top flange. This permits an optimum implementation of a spike with wear-optimized spike pin, on the one hand, and spike body optimized with regard to the holding forces and bedding stiffness, on the other hand, in order to achieve the desired spike characteristics.
In one embodiment, the foot flange of the first spikes is formed with one of a circular-segment-shaped, an oval-segment-shaped and an ellipse-segment-shaped section contour in each case in the section planes formed perpendicular to the longitudinal extent direction of the first spike, the segment ends of which section contour are connected to a rectilinearly extending portion, wherein said rectilinear portion is oriented perpendicular to an axis of symmetry of the circular shape or perpendicular to the relatively long axis of symmetry of the oval or of the ellipse, and wherein said axis of symmetry is oriented so as to enclose an angle If, where 00<y<450, with respect to the axial direction A of the tire.

6 In one embodiment, the top flange and the middle portion are formed in each case with one of a circular, oval and elliptical section contour in the section planes formed perpendicular to the longitudinal extent direction of the first and/or second spike. This embodiment has proven to be particularly advantageous for the durability of the spiked bedding, because, in the case of these forms, no stress peaks are induced in the surrounding rubber matrix. Stress peaks in the rubber matrix owing to sharp-edged forms can induce to the reduction of holding forces owing to relatively intense creep processes in the rubber and cracks in the rubber, whereby, in the long term, would promote to the loss of the spike.
In one embodiment, the contour profile of the encircling grip edge of the second spikes forms a grip edge situated in front in a direction of rotation D and a grip edge situated behind in the direction of rotation D, wherein the grip edge situated in front is formed with, in the direction of rotation D, two rectilinearly extending grip edge portions converging on one another in tapering fashion, wherein a middle, rectilinearly extending grip edge portion is formed between the two grip edge portions converging on one another in tapering fashion, wherein that extent end of one of the two grip edge portions converging on one another in tapering fashion which is situated in front in the direction of rotation D transitions, with the formation of a bend, into one extent end of the middle grip edge portion, and wherein that extent end of the other of the two grip edge portions converging on one another in tapering fashion which is situated in front in the direction of rotation D transitions, with the formation of a bend, into the other extent end of the middle grip edge portion. More specifically, the direction of rotation D may comprise a direction of rotation during forward travel. The design of the grip edge situated in front has a particular influence both on the grip characteristics and on road wear. It must be able to reliably penetrate into the ice surface, because the spike otherwise cannot mechanically interlock. The two grip edge portions converging in tapering fashion permit an effective penetration of the grip edge into the ice in a simple manner, because the effective edge length that impinges as the tire rolls can be reduced to the length of the middle grip edge portion. The middle grip edge portion permit, upon the penetration into the ice surface, a corresponding interlocking face surface for good winter grip.
Here, it is ensured that the spike pin does not impinge on the road surface in punctiform fashion, but rather rolls over the edge of the middle grip edge portion, whereby the wear of the road surface can be reduced.

7 In one embodiment, that grip edge of the second spike which is situated behind in the direction of rotation D is formed with two rectilinearly extending grip edge portions converging on one another in tapering fashion counter to the direction of rotation D and with a middle, concavely curved grip edge portion formed between the two grip edge portions converging on one another in tapering fashion, wherein that extent end of one of the two grip edge portions converging on one another in tapering fashion which is situated behind in the direction of rotation D transitions, with the formation of a bend, into one extent end of the middle grip edge portion, and wherein that extent end of the other of the two grip edge portions converging on one another in tapering fashion which is situated behind in the direction of rotation D transitions, with the formation of a bend, into the other extent end of the middle grip edge portion. The embodiment permits, in a simple manner, a large effective overall length of the grip edge situated behind, with high stability. The grip edge situated behind plays a particular role in the transmission of braking forces. Particularly high braking forces can be transmitted in the case of low tire slip. It is therefore desirable for the grip edge situated behind to be formed with a large overall length in order to ensure the greatest possible support in the interlocking with the ice surface. The embodiment with the middle grip edge portion makes it possible here, despite a large effective overall length, to avoid edge transitions converging in tapering fashion, and possible breakaway tendencies, in the sensitive grip edge region situated behind.
In one embodiment, the encircling grip edge of the second spike forms in each case one lateral grip edge to both sides in the axial direction A, wherein the lateral grip edge has in each case one extent portion in which the grip edge is oriented so as to extend rectilinearly in the circumferential direction U of the tire. The lateral control can be additionally further promoted in this way.
In one embodiment, the foot flange of the second spikes is formed with a circular-segment-shaped, with an oval-segment-shaped or with an ellipse-segment-shaped section contour in each case in the section planes formed perpendicular to the longitudinal extent direction of the first spike, the segment ends of which section contour are connected to a rectilinearly extending portion, wherein said rectilinear portion is oriented perpendicular to an axis of symmetry of the

8 circular shape or perpendicular to the relatively long axis of symmetry of the oval or of the ellipse, and wherein said axis of symmetry is oriented in the circumferential direction U of the tire. By means of this embodiment, the lever ratios at the spike foot, and thus the bedding stiffness, can be optimally set in accordance with the individual requirements of the tire. The .. bedding stiffness has a significant influence on the winter characteristics of the spike in the traction and braking directions, because the different spike movements in the braking and traction directions require different stiffnesses in order to be able to transmit maximum forces.
In one embodiment, between the axially middle extent portion of the tread profile and at least one axially lateral extent portion of the tread profile, there is formed an axial intermediate portion of the tread profile, in which both first spikes and second spikes are formed so as to be distributed over the circumference of the tire. The embodiment permits further design freedom in the individual configuration of the spiked tires. For example, in the case of tires with desired spike sequences with a particularly large number of spikes in the outer profile region, in the case of .. which a strict separation of the spike types have a deficit of the performance in the circumferential direction (braking/traction), the deficit can be compensated through the increased use of spikes of the second type in the transition region. On the other hand, in the case of tires with spike sequences which have a deficit in terms of lateral control and are distinguished by unharmonious, "toxic" driving behavior with a very narrow limit range in terms of lateral control, can be counteracted through the increased use of spikes of the first type with improved lateral control characteristics in the transition region.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be discussed in more detail below on the basis of the exemplary embodiments illustrated in figures 1 to 13. In the figures:
figure 1 shows a circumferential portion of a directional pneumatic vehicle tire with spikes in plan view,

9 figure 2 is an enlarged illustration of a spike from the central extent portion of the tread profile as per detail II of figure 1 in plan view, but without surrounding rubber material, figure 3 shows the spike of figure 2 in a side view in the viewing direction III-III of figure 2, figure 4 shows the spike of figure 2 in a side view in the viewing direction IV-IV of figure 2, figure 5 shows the spike of figure 2 in a side view in the viewing direction V-V of figure 2, figure 6 shows the spike of figure 2 in an additional perspective illustration, figure 7 is an enlarged illustration of a spike from the shoulder region of the tread profile as per detail VII of figure 1 in plan view, but without the surrounding rubber material, figure 8 shows the spike of figure 7 in a side view in the viewing direction VIII-VIII of figure 7, figure 9 shows the spike of figure 7 in a side view in the viewing direction IX-IX of figure 7, figure 10 shows the spike of figure 7 in a side view in the viewing direction X-X of figure 7, figure 11 shows the spike of figure 7 in an additional perspective illustration, figure 12 shows the spike of figure 7 in a further additional perspective illustration, and figure 13 shows the tread profile of figure 1 in an alternative embodiment of the orientation of the spikes arranged in the tire shoulders.
DETAILED DESCRIPTION
Variants, examples and preferred embodiments of the invention are described hereinbelow.
Figure 1 shows a tread profile of a directional pneumatic vehicle tire of a passenger motor vehicle tire with winter characteristics, having multiple profile block rows 22, 23, 24, 25 and 26 of known type arranged adjacent to one another in an axial direction A of the pneumatic vehicle tire.

= 10 The profile block row 22 is, in a known manner, oriented so as to extend in a circumferential direction U over the entire circumference of the pneumatic vehicle tire, and formed from profile block elements which are arranged one behind the other in the circumferential direction U of the pneumatic vehicle tire and which are separated from one another by transverse channels 31.
Likewise, the profile block row 23, the profile block row 24 and the profile block row 25 are each oriented so as to extend in the circumferential direction U over the entire circumference of the pneumatic vehicle tire, and formed in a known manner from profile block elements which are arranged one behind the other in the circumferential direction U and which are in each case separated from one another by transverse channels 31. Likewise, the profile block row 26 is oriented so as to extend in the circumferential direction U over the entire circumference of the pneumatic vehicle tire, and formed in a known manner from profile block elements which are arranged one behind the other in the circumferential direction U and which are in each case separated from one another by transverse channels 31. The profile block rows 22 and 26 are shoulder profile block rows. The profile block rows 23, 24 and 25 are formed in the central extent portion of the profile. The profile block elements of the profile block row 22 and the adjacent profile block elements of the profile block row 23 are formed so as to be separated from one another in an axial direction A by circumferential channels 27 of known type extending in the circumferential direction U. The profile block elements of the profile block row 23 and the adjacent profile block elements of the profile block row 24 are formed so as to be separated from one another in the axial direction A by circumferential .. channels 28. The profile block elements of the profile block row 24 and the adjacent profile block elements of the profile block row 25 are arranged so as to be separated from one another in the axial direction A by circumferential channels 29. The profile block elements of the profile block row 25 and the adjacent profile block elements of the profile block row 26 are arranged so as to be separated from one another in the axial direction A
by circumferential channels 30.
The transverse channels 31 extend in a V shape over the entire axial extent region of the tread profile, through the tread profile from the profile block row 22 formed in the left-hand shoulder to the profile block row 26 formed in the right-hand shoulder.
The direction of rotation D of the pneumatic vehicle tire during forward travel is indicated in figure 1 and figure 2.
In the profile block rows 23 and 25 of the central axial extent portion of the tread profile, .. in each case in a manner distributed over the circumference in different profile block elements, spikes 1 are fastened in spike holes in a known manner, which in a known manner are formed in the profile block elements for the purposes of receiving the spikes 1.
In the profile block rows 22 and 26 of the tire shoulders, in each case in a manner distributed over the circumference in different profile block elements, spikes 41 are fastened in spike holes in a known manner, which in a known manner are formed in the profile block elements for the purposes of receiving the spikes 41.
Figure 2 shows the illustration of a spike 1 in an enlarged illustration and, for the purposes of a simplified illustration, without the surrounding rubber material of the pneumatic vehicle tire. As illustrated in figures 2 to 7, the spike 1 is in a known manner formed from a spike body 2 and from a spike pin 3. The spike body 2 is, from the inside outward as viewed in the radial direction R of the pneumatic vehicle tire, formed in a known manner with a foot flange 4, a waisted middle part 5 adjoining said foot flange, and a top flange 6 adjoining said middle part. The spike body 2 is formed with a height H in the radial direction R of the pneumatic vehicle tire.
Here, the top flange 6 extends in the radial direction R of the pneumatic vehicle tire over an extent height H3 of 0 mm <113 < (0.92 II), and is formed with a cylindrical shell surface with a cylinder diameter D3. In the case of conventional passenger motor vehicle or van tires, the extent height H3 is selected to be (0.25H) < H3 < (0.48 H).
At the transition outward in the radial direction R of the tire to the face surface of the spike body 2 and inward to the waisted middle part 5, the top flange 6 is beveled concentrically with respect to the cylinder axis.
The foot flange 4 is formed with an extent height Hi extending in the radial direction R of the pneumatic vehicle tire, where (0.08 H) < Hi < (0.4 II). In the case of conventional passenger motor vehicle or van tires, the extent height Hi is selected to be (0.1 H) < HI<
(0.2 1-1).
The foot flange 4 is formed with a cylindrical shell surface composed of a shell surface portion 18 and a shell surface portion 19, wherein the shell surface portion 18 forms the segment of a cylinder shell surface with cylinder axis and diameter Di, and the shell surface portion 19 forms a planar surface which intersects the imaginary completed cylinder shell surface of the segment parallel to the cylinder axis.
As can be seen in figure 2 and figure 5, in the section planes perpendicular to the main extent direction of the spike 1 and thus perpendicular to the radial extent direction R of the tire, the shell surface portion 19 is formed so as to extend rectilinearly, and the portion 18 is in the shape of a circular segment. The shell surface portion 19 and thus the rectilinear section contour lines are, in the direction of rotation D, positioned in front of the position =

of the center of mass Si of the foot flange 18 at a distance a from the position of the center of mass Si. The cylinder-segment-shaped shell portion 18 and thus the circular-segment-shaped section contour line extend counter to the direction of rotation D as far as into a position at a distance b from the center of mass Si of the foot flange 4.
Here, the distances b and a are configured such that b> a. Likewise, (a + b) < Di.
As can be seen in figures 3 to 6, the foot flange 4 is also of beveled form at its transition to the face surface that delimits the spike body 2 inward in the radial direction R of the tire.
Thc middle part 5 of the spike body 2 is, in a known manner, of waisted form, and extends over an extent height H2 measured in the longitudinal extent direction of the spike 1 and thus in the radial direction R of the tire, where 0 mm < Hz< (0.92 II). In the case of conventional passenger motor vehicle or van tires, the extent height H2 is selected to be (0.4H) H2 5_ (0.55 H).
In all cross-sectional planes perpendicular to the main extent direction of the spike 1 and thus to the radial extent direction R of the tire, the middle part 5 is formed with a circular section contour of its shell surface. Here, proceeding from the diameter D3 at the position of the transition to the top flange 6, the diameter of the circular section contours becomes continuously smaller along the extent of the spike 1 in the direction of the foot flange 4 until a minimum value D2 is reached, and after said minimum value has been reached, said diameter becomes continuously larger as far as the transition to the foot flange 4.
In the face surface that delimits the spike body 2 outward in the radial direction R of the tire at its top flange 6, there is formed, in a known manner, an opening for receiving and for the fastening of the spike pin 3, in which opening the spike pin 3 is fastened when in the installed state in the pneumatic vehicle tire. The spike pin 3 extends in the tire, from the face surface that forms a delimitation radially outward at the top flange 6 of the spike body 2, further outward in the radial direction R of the pneumatic vehicle tire, and forms the spike tip here. The spike tip and thus the spike pin 3 is delimited outward in the radial direction R of the tire with a surface that forms a plateau 20. The transition between the shell surface of the spike pin 3 and the plateau 20 has a sharp edge, and here forms a grip edge 7 running in encircling fashion around the spike pin 3. A radial elevation 21 extends outward in the radial direction R out of the plateau 20 at a distance from the encircling grip edge 7 in a known manner, which elevation can facilitate the rolling movement.
The encircling grip edge 7 is in this case formed symmetrically with respect to a straight line t which forms a line of symmetry. Here, the line of symmetry t is formed so as to enclose an angle of inclination [3, where 0 <13 < 20 , with the circumferential direction U.
In the exemplary embodiment illustrated in figure 1, the angle J3 is selected such that r3 =-00.
The encircling grip edge 7 is formed, with a at its extent section situated in front in the direction of rotation D during forward travel, with a grip edge 8 situated in front, and at its extent section situated behind in the direction of rotation D during forward travel, with a grip edge 9 situated behind, and with grip edge portions 16 and 17 which delimit the spike pin 3 in the axial direction A of the pneumatic vehicle tire, which grip edge portions are each oriented so as to extend in the circumferential direction U of the pneumatic vehicle tire.
The grip edge 8 situated in front is formed from two lateral, in each case rectilinearly extending grip edge portions 10 and 12, and from a middle extent portion 11 which is arranged 'in the axial direction A of the pneumatic vehicle tire between the two lateral grip edge portions 10 and 12. The lateral, rectilinear grip edge portions 10 and 12 are in this case formed so as to be oriented so as to converge on one another in tapered fashion in V-shaped or arrow-shaped form as viewed in the direction of rotation D. The middle extent portion 11 is formed so as to be oriented so as to extend rectilinearly in the axial direction A of the pneumatic vehicle tire. Here, that extent end of the lateral grip edge portion 10 which is situated at the front as viewed in the direction of rotation D forms one extent end, directed toward the grip edge portion 10, of the middle extent portion 11, and transitions there, with the inclusion of a bend in the extent profile of the grip edge 8 situated in front, and thus of the encircling grip edge 7, into the middle extent portion 11.
Likewise, the front extent end, directed in the direction of rotation D, of the lateral grip edge portion 12 forms that extent end of the middle extent portion 11 which is directed toward the lateral extent portion 12, and transitions there, with the inclusion of a bend in the extent profile of the grip edge 8 situated in front, and thus of the encircling grip edge 7, into the middle extent portion 11.

That extent end of the lateral grip edge portion 10 which is situated at the rear as viewed in the direction of rotation D forms that extent end of the grip edge portion 16 which is situated at the front as viewed in the direction of rotation D, and transitions, with the inclusion of a bend in the extent profile of the encircling grip edge 7, into the grip edge

10 portion 16. Likewise, that extent end of the lateral grip edge portion 12 which is situated at the rear as viewed in the direction of rotation D forms that end of the grip edge portion 17 which is situated at the front in the direction of rotation D, and transitions there, with the inclusion of a bend in the extent profile of the encircling grip edge 7, into the grip edge portion 17.
The grip edge 9 situated behind in the direction of rotation D is formed from two lateral extending grip edge portions 13 and 15 and from a middle extent portion 14 which is arranged in the axial direction A of the pneumatic vehicle tire between the two lateral grip edge portions 13 and 15. The lateral grip edge portions 13 and 15 are formed so as to extend rectilinearly and so as to be oriented so as to converge on one another in tapered fashion in V-shaped or arrow-shaped form as viewed counter to the direction of rotation D.
The middle extent portion 14 is formed with a concavely curved curvature profile, that is to say the curvature radius of the curvature profile 14 is formed on that side of the curvature line which points away from the spike pin 3.
That extent end of the lateral grip edge portion 13 which is formed behind in the direction of rotation D forms that extent end of the middle extent portion 14 which is formed toward the grip edge portion 13, and transitions there, with the inclusion of a bend in the extent profile of the rear grip edge 9, and thus of the encircling grip edge 7, into the extent portion 14. That extent end of the lateral grip edge portion 15 which is formed behind in the direction of rotation D forms that extent end of the middle extent portion 14 which is formed toward the grip edge portion 15, and transitions there, with the inclusion of a bend in the extent profile of the rear grip edge 9, and thus of the encircling grip edge 7, into the extent portion 14.
That extent end of the grip edge portion 13 which is situated in front in the direction of rotation D forms that extent end of the grip edge portion 16 which is situated behind in the direction of rotation D, and transitions there, with the inclusion of a bend in the extent profile of the encircling grip edge 7, into the grip edge portion 16. That extent end of the grip edge portion 15 which is situated in front in the direction of rotation D
forms that extent end of the grip edge portion 17 which is situated behind in the direction of rotation D, and transitions there, with the inclusion of a bend in the extent profile of the encircling grip edge 7, into the grip edge portion 17.
The projection of the encircling grip edge 7 in the axial direction A of the tire has a projection length e. The projection of the encircling grip edge 7 in the circumferential direction U of the tire has a projection length c, which corresponds to the width of the spike pin 3 at the radial position of the grip edge 7 and indicates the effective grip edge length of the spike 1 in the circumferential direction U. The projection length e corresponds to the extent length, measured in the circumferential direction U, of the spike pin 3 at the radial position of the grip edge 7, and indicates the effective grip edge length of the spike in the axial direction A of the tire. Here, c and e are dimensioned such that c > e.
The extent length, measured in the axial direction, of the middle extent portion 11 of the front grip edge 8 is in this case configured in the range from 30% to 80% of the projection length c. The extent length, measured in the axial direction A, of the middle extent portion 14 of the rear grip edge 9 is in this case configured to be greater than the extent length, measured in the axial direction A, of the middle extent portion 11 of the front grip edge 8.
As illustrated in figures 3, 5 and 2, in one exemplary embodiment of the spike 1, the center of mass S1 of the foot flange 4 of the spike body 2, the center of mass S2 of the middle part 5 of the spike body 2, the center of mass S3 of the top flange 6 and the center of mass S4 of the spike pin 3 lie on a common straight line g, which extends in the radial direction R of the pneumatic vehicle tire. In one exemplary embodiment, the overall center of mass S (not shown) of the spike 1 also lies on said straight line.
.. In the exemplary embodiments of the spike 1 described and illustrated in the figures, the middle part 5 and the top flange 6 are, in terms of their shell surface, in each case of circular form in the section planes perpendicular to the main extent direction of the spike 1 and to the radial extent direction R of the tire.
In another embodiment which is not illustrated, the section contours of the shell surfaces of the top flange 6 and of the middle part 5 of the spike 1 are each of oval or elliptical form, wherein the relatively large main axis of the oval or of the ellipse is oriented in the circumferential direction U of the pneumatic vehicle tire. The above-stated diameters D2 and D3 then in each case form the relatively large diameter of the respective ellipse or of the oval.
In the exemplary embodiments of the spike 1 described above and illustrated in the figures, the foot flange is of cylinder-segment-shaped form in the region of its shell surface portion 18, with a circular outline of the cylinder and with a circular-segment-shaped section line .. contour of the cylinder segment shape in the section planes perpendicular to the main extent direction of the spike 1 and to the radial extent direction R of the tire.
In an alternative embodiment of the spike 1 which is not illustrated, the shell surface portion 18 is a cylinder-segment-shaped portion with an oval or elliptical outline of the cylinder and with an oval-segment-shaped or ellipse-segment-shaped section line contour of the cylinder segment shape in the section planes perpendicular to the main extent direction of the spike 1 and to the radial extent direction R of the tire, wherein the relatively large main axis of the ellipse or of the oval is oriented in the circumferential extent direction U of the pneumatic vehicle tire. The above-stated diameter Di then .. corresponds to the relatively large diameter of the oval or of the ellipse.

Figure 7 shows the illustration of a spike 41 in an enlarged illustration and, for the purposes of a simplified illustration, without the surrounding rubber material of the pneumatic vehicle tire. As illustrated in figures 7 to 12, the spike 41 is in a known manner formed from a spike body 42 and from a spike pin 43. The spike body 42 is, from the inside outward as viewed in the radial direction R of the pneumatic vehicle tire, formed in a known manner with a foot flange 44, a waisted middle part 45 adjoining said foot flange, and a top flange 46 adjoining said middle part. The spike body 42 is formed with a height H' in the radial direction R of the pneumatic vehicle tire.
to Here, the top flange 46 extends in the radial direction R of the pneumatic vehicle tire over an extent height H'3 of 0 mm < H'3 < (0.92 H'), and is formed with a cylindrical shell surface with a cylinder diameter D'3. In the case of conventional passenger motor vehicle or van tires, the extent height H3 is selected to be (0.25H') <1113 < (0.48 H').
At the transition outward in the radial direction R of the tire to the face surface of the spike body 42 and inward to the waisted middle part 45, the top flange 46 is beveled concentrically with respect to the cylinder axis.
The foot flange 44 is formed with an extent height H'1 extending in the radial direction R
of the pneumatic vehicle tire, where (0.08 H') < H't < (0.4 H'). In the case of conventional passenger motor vehicle or van tires, the extent height H'i is selected to be (0.1 H') < H't <
(0.2 H').
As can be seen in figures 7 to 12, the foot flange 44 is also of beveled form at its transition to the face surface that delimits the spike body 42 inward in the radial direction R of the tire.
The middle part 45 of the spike body 42 is, in a known manner, of waisted form, and extends over an extent height H'2 measured in the longitudinal extent direction of the spike 41 and thus in the radial direction R of the tire, where 0 mm < H'2 < (0.92 H'). In the case of conventional passenger motor vehicle or van tires, the extent height Hz is selected to be (0.4H') < H'2 S. (0.55 H').
In all cross-sectional planes perpendicular to the main extent direction of the spike 41 and thus to the radial extent direction R of the tire, the middle part 45 is formed with a circular section contour of its shell surface. Here, proceeding from the diameter D'3 at the position of the transition to the top flange 6, the diameter of the circular section contours becomes continuously smaller along the extent of the spike 41 in the direction of the foot flange 44 until a minimum value D'2 is reached, and after said minimum value has been reached, said diameter becomes continuously larger as far as the transition to the foot flange 44.
to In the face surface that delimits the spike body 42 outward in the radial direction R of the tire at its top flange 46, there is formed, in a known manner, an opening for receiving and for the fastening of the spike pin 43, in which opening the spike pin 43 is fastened when in the installed state in the pneumatic vehicle tire. The spike pin 43 extends in the tire, from the face surface that forms a delimitation radially outward at the top flange 46 of the spike body 42, further outward in the radial direction R of the pneumatic vehicle tire, and forms the spike tip here. The spike tip and thus the spike pin 43 is delimited outward in the radial direction R of the tire with a surface that forms a plateau 54. The transition between the shell surface of the spike pin 43 and the plateau 54 has a sharp edge, and here forms a grip edge 47 running in encircling fashion around the spike pin 43. A radial elevation 55 extends outward in the radial direction R out of the plateau 54 at a distance from the grip edge 47 in a known manner, which elevation can facilitate the rolling movement.
The encircling grip edge 47 of the spike tip 43 is formed with a grip edge 48 situated in .. front of the spike tip in the direction of rotation D of the tire, with a grip edge 49 situated behind the spike tip in the direction of rotation D, with a lateral grip edge 50 formed in the axial direction A direction of the spike tip 43 which points away from the central extent portion of the pneumatic vehicle tire, and with a lateral grip edge 51 formed in the axial direction A direction of the spike tip 43 which points toward the middle extent portion of the tread profile. The encircling grip edge 47 is in this case formed symmetrically with respect to a straight line m which forms a line of symmetry. Here, the straight line m that forms the line of symmetry is oriented so as to enclose an angle of inclination a, where 0 < a < 35 , with the axial direction A of the pneumatic vehicle tire.
In figure 1 and in figure 7, the angle a has been selected to be a = 0 .

The lateral grip edge portions 50 and 51 are oriented perpendicular to the line of symmetry m and thus ¨ in the exemplary embodiment illustrated in figure 1 and figure 7 ¨
perpendicular to the axial direction A. Here, the lateral grip edge 51 is formed so as to be shorter than the lateral grip edge 50. That extent end of the grip edge 51 which is situated 10 in front in the direction of rotation D forms that extent end of the grip edge 48 which points toward the tire center, and transitions into the grip edge 48 with the inclusion of a bend in the contour profile of the encircling grip edge 47. That extent end of the grip edge 51 which is situated behind in the direction of rotation D forms that extent end of the grip edge 49 which points toward the tire center, and transitions into the grip edge 49 with the 15 formation of a bend in the contour profile of the encircling grip edge 47. That extent end of the grip edge 50 which is situated in front in the direction of rotation D
forms that extent end of the grip edge 48 which points toward the tire outer side, and transitions into the grip edge 48 with the formation of a bend of the contour profile of the encircling grip edge 47.
That extent end of the grip edge 50 which is situated behind in the direction of rotation D
20 forms that extent end of the grip edge 49 which points toward the tire outer side, and transitions into the grip edge 49 with the formation of a bend of the contour profile of the encircling grip edge 47. The transition between grip edge 48 and grip edge 50 and between grip edge 50 and grip edge 49 is in this case of rounded form. The grip edges 48 and 49 extend between grip edge 50 and grip edge 51 so as to converge on one another in V-shaped fashion in the direction of the tire center, and in their elongation beyond the grip edge 51, intersect the line of symmetry m. Accordingly, the two grip edges 48 and 49 spread apart in V-shaped fashion, enclosing an angle, in the extent direction from the grip edge 50 toward the tire outer side as far as their extent end at the grip edge 50.
In the exemplary embodiment illustrated, the grip edge 50 and the grip edge 51 are in each case formed so as to extend rectilinearly.

In another exemplary embodiment which is not illustrated, the grip edge 50 is of concavely curved form, that is to say is curved about a curvature radius about a middle point which is arranged on the line of symmetry m on the side pointing away from the grip edge 50 of the spike tip 43.
The projection of the encircling grip edge 47 in the axial direction A of the tire has a projection length f, where f> e. The projection of the encircling grip edge 47 in the circumferential direction U of the tire has a projection length k, where k <c, which corresponds to the width of the spike pin 43 at the radial position of the grip edge 47 and indicates the effective grip edge length of the spike 41 in the circumferential direction U. The projection length f corresponds to the extent length, measured in the circumferential direction U, of the spike pin 43 at the radial position of the grip edge 47, and indicates the effective grip edge length of the spike in the axial direction A of the tire.
Here, k and fare dimensioned such that k> f.
The foot flange 44 of the spike body 42 is, analogously to the foot flange 4 of the spike body 2 of the spike 1, formed with a cylinder-segment-shaped shell surface with the shell surface portions 52 and 53. Here, the shell surface portion 52 forms the curved cylinder shell form of the cylinder segment, and the shell surface portion 53 forms the planar form, which truncates the cylinder, of the cylinder segment. In the cross-sectional planes perpendicular to the spike extent axis gi, the flange 44 thus forms a circular-segment-shaped section contour, wherein the section contour of the shell surface portion 52 forms the circular portion and the section contour of the shell surface portion 53 forms the rectilinear connecting portion. The circle of the circular segment is formed with a diameter D'3. The circular segment contour is formed symmetrically with respect to a straight-line axis of symmetry n that intersects the spike axis gi, wherein the straight-line extent portion, formed by the planar cylinder shell surface 53, of the circular segment perpendicularly intersects the line of symmetry n. The circle middle point lies within the circular segment.
The line of symmetry n is oriented so as to enclose an angle of inclination y, where 00 < y < 45 , with the axial direction A. In the exemplary embodiment illustrated in figures 1 and 7, y = a = 0 .
As can be seen in figure 7, the shell portion 53 is arranged on that side of the foot flange 44 which points away from the middle axial extent portion of the tread profile.
Figure 13 shows an exemplary embodiment of a tread profile which is designed similarly to the tread profile of figure 1, but in which the spikes 41 are formed so as to enclose an angle a = y = 13 .
Figures 1 and 13 each illustrate an exemplary embodiment of a tread profile in which a central profile block row 24 without spikes is formed between the middle profile block rows 23 and 25. In an alternative embodiment which is not illustrated, spikes 1 are also formed in the central profile block row 24.
Figures 1 and 13 each show an exemplary embodiment of a tread profile in which in each case only spikes 41 are formed in the shoulder profile block rows and only spikes 1 are formed in the middle profile block rows formed between the shoulder profile block rows.
In another embodiment which is not illustrated, only spikes 41 are formed in the shoulder profile block rows and only spikes 1 are formed in the middle profile block rows.
Furthermore, between shoulder profile block rows and central middle profile block rows, there are formed further intermediate profile block rows, which likewise extend over the entire circumference of the pneumatic vehicle tire and in which both spikes 1 and spikes 41 are arranged so as to be distributed over the circumference and over the axial extent of the profile block row.
In the exemplary embodiments described and illustrated in the figures, the central part 45 and the top flange 46 are, in terms of their shell surface, in each case of circular form in the section planes perpendicular to the main extent direction of the spike 41 and to the radial extent direction R of the tire.
In another embodiment which is not illustrated, the section contours of the shell surfaces of the top flange 46 and of the central part 45 are each of oval or elliptical form, wherein the relatively large main axis of the oval or of the ellipse is oriented in the axial direction A of the pneumatic vehicle tire. The above-stated diameters D'2 and IY3 then in each case form the relatively large diameter of the respective ellipse or of the oval.
In the exemplary embodiments described above and illustrated in the figures, the foot flange 44 of the spike 41 is of cylinder-segment-shaped form, with a circular outline of the cylinder and with a circular-segment-shaped section line contour of the cylinder segment shape in the section planes perpendicular to the main extent direction of the spike 41 and to the radial extent direction R of the tire.
In an alternative embodiment which is not illustrated, the shell surface portion 53 is a cylinder-segment-shaped portion with an oval or elliptical outline of the cylinder and with an oval-segment-shaped or ellipse-segment-shaped section line contour of the cylinder segment shape in the section planes perpendicular to the main extent direction of the spike 41 and to the radial extent direction R of the tire, wherein the relatively large main axis of the ellipse or of the oval is oriented in the extent direction of the direction of the axis of symmetry n. The above-stated diameter D then corresponds to the relatively large diameter of the oval or of the ellipse.

LIST OF REFERENCE DESIGNATIONS
(Part of the description) 1 Spike body 2 Spike pin 3 Foot flange 4 Waisted middle portion 5 Top flange 6 Encircling grip edge 7 Grip edge situated in front 8 Grip edge situated behind 9 Grip edge portion 10 Middle grip edge portion

11 Grip edge portion

12 Grip edge portion

13 Middle grip edge portion

14 Grip edge portion

15 Grip edge portion

16 Grip edge portion

17 Shell contour portion

18 Shell contour portion

19 Plateau

20 Elevation

21 Profile block row

22 Profile block row

23 Profile block row

24 Profile block row

25 Profile block row

26 Circumferential channel

27 Circumferential channel

28 Circumferential channel

29 Circumferential channel

30 Transverse channel

31 Sipe 41 Spike 42 Spike body 43 Spike pin 44 Foot flange 45 Waisted middle portion 46 Top flange 47 Encircling grip edge 48 Grip edge situated in front 49 Grip edge situated behind 50 Grip edge portion 51 Grip edge portion 52 Shell contour portion 53 Shell contour portion 54 Plateau 55 Elevation

Claims

1) A vehicle tire comprising a tread profile and first and second spikes each formed with a spike tip with an encircling grip edge, having two axially lateral extent portions of the tread profile, wherein in each case only the first spikes are formed, and having an axially middle extent portion of the tread profile which is formed between two lateral extent portions and wherein only the second spikes are formed, wherein the spike tip of the second spikes is, with a contour profile of the encircling grip edge of the second spikes, formed symmetrically with respect to a first axis which is oriented so as to enclose an angle 13 with a circumferential direction of the tire, wherein 0°<= .beta. <=20°, wherein the spike tip of the first spikes is, with a contour profile of the encircling grip edge of the first spikes, formed symmetrically with respect to a first axis which is oriented so as to enclose an angle a with an axial direction of the tire, wherein 0°<= .alpha. <=35°, wherein the contour profile of the encircling grip edge of the first spikes has a different form than the contour profile of the encircling grip edge of the second spikes, and wherein the spike tip of the first spikes is, with the contour profile of the grip edge of the first spikes, formed in each case asymmetrically with respect to planes that are perpendicular to the first axis, wherein a length of a projection, formed in the axial direction, of the encircling grip edge of the first spikes is in each case greater than a length of a projection, formed in the axial direction, of the encircling grip edge of the second spikes.

2) The vehicle tire as defined in claim 1, wherein a width, measured perpendicular to the first axis of the encircling grip edge of the first spike, of the surface enclosed by the contour profile of the grip edge increases along an extent of the first axis toward a side pointing away from the middle extent portion of the tread profile.

3) The vehicle tire as defined in claim 2, wherein the width of the surface enclosed by the contour profile of the grip edge increases in continuous fashion along the extent of the first axis.

4) The vehicle tire as defined in claim 2 or 3, wherein the contour profile of the encircling grip edge of the first spikes has in each case one rectilinear extent portion to both sides of the first axis, wherein the rectilinear extent portions intersect, at least in their elongation on that side of the encircling grip edge which points toward the middle extent portion of the tread profile, in the first axis, and proceeding from the intersection point run in V-shaped fashion, enclosing an angle, along the extent of the first axis toward the side pointing away from the middle extent portion of the tread profile as far as their extent end, wherein the two extent ends are connected to one another by a third extent portion, extending substantially perpendicular to the first axis, of the grip edge.

5) The vehicle tire as defined in claim 4, wherein the third extent portion is formed to extend in one of rectilinear and concavely curved fashion.

6) The vehicle tire as defined in any one of claims 1 to 5, wherein the first and/or the second spikes are composed in each case of a spike body and a spike pin and wherein the spike pin, the spike tip, and the spike body is formed from a foot flange, a middle portion and a top flange.

7) The vehicle tire as defined in claim 6, wherein the foot flange of the first spikes is formed with one of a circular-segment-shaped, an oval-segment-shaped and an ellipse-segment-shaped section contour in each case in the section planes formed perpendicular to the longitudinal extent direction of the first spike, the segment ends of which section contour are connected to a rectilinearly extending portion, wherein said rectilinear portion is oriented perpendicular to an axis of symmetry n of the circular shape or perpendicular to the relatively long axis of symmetry of the oval or of the ellipse, and wherein the axis of symmetry is oriented so as to enclose an angle 7, wherein 0°<=.gamma.<=45°, with respect to the axial direction of the tire.

8) The vehicle tire as defined in claim 6, wherein the top flange and the middle portion are formed in each case with one of a circular, oval and elliptical section contour in the section planes formed perpendicular to the longitudinal extent direction of the first and/or second spike.

9) The vehicle tire as defined in any one of claims 1 to 8, wherein the contour profile of the encircling grip edge of the second spikes forms a grip edge situated in front in a direction of rotation and a grip edge situated behind in the direction of rotation, wherein the grip edge situated in front is formed with, in the direction of rotation, two rectilinearly extending grip edge portions converging on one another in tapering fashion, wherein a middle, rectilinearly extending grip edge portion is formed between the two grip edge portions converging on one another in tapering fashion, wherein that extent end of one of the two grip edge portions converging on one another in tapering fashion which is situated in front in the direction of rotation transitions, with the formation of a bend, into one extent end of the middle grip edge portion, and wherein that extent end of the other of the two grip edge portions converging on one another in tapering fashion which is situated in front in the direction of rotation transitions, with the formation of a bend, into the other extent end of the middle grip edge portion.

10) The vehicle tire as defined in claim 9, wherein the direction of rotation comprises a direction of rotation during forward travel.

11) The vehicle tire as defined in claim 10, wherein that grip edge of the second spike which is situated behind in the direction of rotation is formed with two rectilinearly extending grip edge portions converging on one another in tapering fashion counter to the direction of rotation and with a middle, concavely curved grip edge portion formed between the two grip edge portions converging on one another in tapering fashion, wherein that extent end of one of the two grip edge portions converging on one another in tapering fashion which is situated behind in the direction of rotation transitions, with the formation of a bend, into one extent end of the middle grip edge portion, and wherein that extent end of the other of the two grip edge portions converging on one another in tapering fashion which is situated behind in the direction of rotation transitions, with the formation of a bend, into the other extent end of the middle grip edge portion.

12) The vehicle tire as defined in any one of claims 1 to 11, wherein the encircling grip edge of the second spike forms in each case one lateral grip edge to both sides in the axial direction, wherein the lateral grip edge has in each case one extent portion in which the grip edge is oriented so as to extend rectilinearly in the circumferential direction of the tire.

13) The vehicle tire as defined in any one of claims 6 to 12, wherein the foot flange of the second spikes is formed with one of a circular-segment-shaped, with an oval-segment-shaped and with an ellipse-segment-shaped section contour in each case in the section planes formed perpendicular to the longitudinal extent direction of the second spike, the segment ends of which section contour are connected to a rectilinearly extending portion, wherein said rectilinear portion is oriented perpendicular to an axis of symmetry of the circular shape or perpendicular to the relatively long axis of symmetry of the oval or of the ellipse, and wherein said axis of symmetry is oriented in the circumferential direction of the tire.

14) The vehicle tire as defined in any one of claim 1 to 13, wherein, between the axially middle extent portion of the tread profile and at least one axially lateral extent portion of the tread profile, there is formed an axial intermediate portion of the tread profile, in which both first spikes and second spikes are formed so as to be distributed over a circumference of the tire.