CA2773438C

CA2773438C - Tread profile of a pneumatic vehicle tire

Info

Publication number: CA2773438C
Application number: CA2773438A
Authority: CA
Inventors: Jan Schlittenhard; Norbert Kendziorra
Original assignee: Continental Reifen Deutschland GmbH
Current assignee: Continental Reifen Deutschland GmbH
Priority date: 2009-11-16
Filing date: 2010-09-14
Publication date: 2015-12-29
Anticipated expiration: 2030-09-14
Also published as: DE102009044547A1; CN102612439B; WO2011057834A1; EP2501562A1; CN102612439A; EP2501562B1; CA2773438A1

Abstract

The invention relates to a tread profile of a pneumatic vehicle tire having a plurality of radially raised profile elements (1) spaced apart from one another by means of scores (2, 3, 4) or grooves, each being delimited in the radial direction R to the outside by an outer surface (8) forming the ground contact surface, wherein at least one spike (5) is formed in at least one profile element (1) which is anchored by the spike body (6) thereof in the rubber material of the profile element (1) and designed having a spike point which extends out of the spike body (6) in the radial direction R of the tire and ends in a radial position outside that of the outer surface (8) of the profile element delimiting the profile element (1) radially to the outside and forming the ground contact surface, wherein there is a recess (9) formed in the outer surface (8) delimiting the profile element (1) radially to the outside and forming the ground contact surface for expelling ice which surrounds the spike (5) in a substantially ring-shaped manner.

Description

Description Tread profile of a pneumatic vehicle tire The invention relates to a tread profile of a pneumatic vehicle tire, having a plurality of radially elevated profile elements which are spaced apart from one another by grooves or furrows and which are in each case delimited outward in the radial direction R by an envelope surface which forms the ground contact surface, wherein in at least one profile element there is formed at least one spike which is anchored with its spike body in the rubber material of the profile element and which is formed with a spike tip, which spike tip extends out of the spike body in the radial direction R of the tire and ends at a radial position outside the envelope surface, which delimits the profile element radially to the outside and which forms the ground contact surface, of the profile element.
Vehicle tires of said type are known. In conventional pneumatic vehicle tires with spikes, the spikes are inserted into the profile blocks at positions provided for this purpose. For this purpose, spike holes into which in each case one spike is inserted are formed in the profile block element. Here, to ensure correct seating of the spike, no sipes are formed in the area around the spike.
The general mode of operation of spiked tires on ice is based on multiple effects. Firstly, the spike pin of the spike penetrates into the ice in the roadway and engages mechanically into the ice in a tooth-like manner. During braking and traction processes, relative movements (slip) furthermore occur between the tire and the ice-covered roadway. Said relative movements have the effect that the spike is pulled through the ice,

- 2 -and in so doing cuts a groove into the surface of the ice. During this chip-forming process, ice on the surface is broken up. During the destruction of the ice, energy is converted by the formation of new surfaces. Said energy conversion is perceived for example in the shortening of the brake travel. The broken-up ice however takes up a larger volume than the compact ice of the roadway. Furthermore, the broken-up ice must yield to the spike pin during the slipping process, that is to say said ice must be at least temporarily transported. Furthermore, in the case of the spiked tire, there is also a friction effect between the rubber material surrounding the spike pin and the ice surface.
During ice, braking and traction tests by the applicant, however, it has been found that the displacement, that is to say transportation, of the chipped-away ice is often incomplete and the broken-up ice partially accumulates around the spike under said profile block, and is not expelled to the profile grooves delimiting the profile block elements. This may have the result that the spike cannot fully impart the above-stated effects in the desired way. The ice material which has accumulated around the spike pushes the rubber material surrounding the spike, together with the spike, as it passes through the tire contact patch, radially inward in the direction of the tire and away from the road surface, such that both the rubber material surrounding the spike and also the edges, which are important for engagement with the ice, of the spike pin are forced away from the road surface by the scratched-away ice material. This reduces the engagement action of the spike and therefore the mechanical tooth-like engagement of the spike into the ice, and the chip-forming action of the spike during braking and under traction. Furthermore, the rubber-ice friction in the area of the spike is reduced.

- 3 -It is the object of the invention to permit improved engagement with the ice in the case of a tread profile of said type.
The object is achieved according to the invention by means of the design of a tread profile of a pneumatic vehicle tire, having a plurality of radially elevated profile elements which are spaced apart from one another by grooves or furrows and which are in each case delimited outward in the radial direction by an envelope surface which forms the ground contact surface, wherein in at least one profile element there is formed at least one spike which is anchored with its spike body in the rubber material of the profile element and which is formed with a spike tip, which spike tip extends out of the spike body in the radial direction of the tire and ends at a radial position outside the envelope surface, which delimits the profile element radially to the outside and which forms the ground contact surface, of the profile element, characterized in that, in the envelope surface which delimits the profile element radially to the outside and which forms the ground contact surface, there is formed a depression which serves for receiving ice and which substantially annularly surrounds the spike, wherein the depression in the envelope surface is delimited by an outer contour line which delimits the depression at the side positioned away from the spike, and is delimited on the side positioned toward the spike by said spike.
In accordance with a preferred embodiment, there is provided a tread profile of a pneumatic vehicle tire, having a plurality of radially elevated profile elements which are spaced apart from one another by ,

- 4 -grooves or furrows and which are in each case delimited outward in the radial direction R by an envelope surface which forms the ground contact surface, wherein in at least one profile element there is formed at least one spike which is anchored with its spike body in the rubber material of the profile element and which is formed with a spike tip, which spike tip extends out of the spike body in the radial direction R of the tire and ends at a radial position outside the envelope surface, which delimits the profile element radially to the outside and which forms the ground contact surface, of the profile element, in which, in the envelope surface which delimits the profile element radially to the outside and which forms the ground contact surface, there is formed a depression which serves for receiving ice and which substantially annularly surrounds the spike.
Preferably, the depression which surrounds the spike forms a receiving reservoir for receiving the chipped-away ice. The chipped-away ice is received in the reservoir as the tire contact patch is rolled through.
Lifting of the rubber material from the road surface as the tire contact patch is passed through can thus be substantially prevented. The spike pin remains in secure engagement with the ice-covered road surface, as a result of which the grip action is increased and the chip-forming effect during braking and traction processes is maintained. The rubber material formed outside the depression remains in secure rubber-ice frictional contact.
Particularly advantageous is an embodiment of a tread profile, wherein the depression in the envelope surface is delimited by an outer contour line which delimits the depression at the side pointing away from the spike, and is delimited on the side pointing toward the

- 5 -spike by the spike. As a result of this selected delimitation, a facility for receiving chipped-away ice is provided directly adjacent to the spike without the rubber material which surrounds the spike being lifted from the ice surface and the spike pin being raised out of intensive contact with the ice. A clearly bordered outer contour line in the envelope surface leads to the generation of an edge effect with a pressure peak, as a result of which the passage of chipped-away ice material into the tire-ice contact area can be prevented. A reduction in rubber-ice friction can be prevented in this way.
Particularly advantageous is another embodiment of a tread profile, wherein the spike body has a cylindrical envelope surface with a cross section of its envelope surface formed perpendicular to the cylinder axis, which cross section is formed with a maximum outer diameter D of 5.5 mm D 7.5 mm, wherein the spike body has in particular a round cylindrical envelope surface. Such a design of the spike body geometry permits an individual optimization of the conflicting aims of spike engagement into the ice and abrasion behavior.
Particularly advantageous is another embodiment of a tread profile, wherein the depression in the envelope surface has a width F measured in the radial direction R1 with respect to the spike axis S, the value of said width being 2 mm F 10 mm over its extent over the circumference of the spike. Said design makes it possible for the depression to be configured to be of an optimum size which is capable of receiving ice chips formed during the slipping process. The design is small enough to ensure the rubber surface available for ice friction, and large enough to ensure the effect according to the invention.

µ

- 6 -Particularly advantageous is an embodiment of a tread profile, wherein the depression is formed with a depth T, measured in the radial direction R of the tire from the envelope surface to the depression base, of 0.5 mm T 1 mm. A configuration of this type yields an optimum compromise between the formation of an ice chip reservoir and an adequate supporting action for the spike under load, in order to ensure an optimum engagement action.
Particularly advantageous is an embodiment of a tread profile, wherein the depth T of the depression is formed so as to increase continuously - in particular linearly - toward the spike axis in the radial direction R1. This provides increased support for the spike in the direct vicinity of the spike, as well as protecting the spike body against abrasion by sand and stones, wherein the formation of the ice chip reservoir is ensured.
Particularly advantageous is an embodiment of a tread profile, wherein the depression in the envelope surface is formed with an outer contour line which delimits the depression at the side pointing away from the spike and which has a curved profile. If one does not penetrate fully into the ice, it causes the rubber material in the direct vicinity thereof to lift up. The curved profile of the depression naturally addresses this fact, wherein the occurring edge effect can prevent ice particles from passing into the tire-ice contact area.
Particularly advantageous is an embodiment of a tread profile, wherein the outer contour line is of circular, oval or elliptical form. This configuration permits an optimized adaptation to the individual special requirements, in particular in the case of spikes with

- 7 -spike bodies with non-circular cylindrical envelope surfaces, and in the case of spikes with spike pins with non-circular body geometries.
Particularly advantageous is an embodiment of a tread profile, wherein the depression in the envelope surface is formed with an outer contour line which delimits the depression at the side pointing away from the spike and which has a polygonal - in particular star-shaped serrated - profile. This configuration permits an optimized adaptation to the individual special requirements, in particular in the case of spikes with spike bodies which have geometries which differ significantly from the round cylindrical shape of the envelope surfaces, and in the case of spikes with spike pins which have geometries which differ significantly from the round cylindrical shape of the body geometries.
Particularly advantageous is an embodiment of a tread profile, wherein in the envelope surface which delimits the profile element radially to the outside, there are additionally formed one or more channel-like depressions with a width BK of 1 mm BK 5 mm and with an - in particular constant - depth TK of 0.5 mm TK
1.5 mm, which channel-like depressions are formed so as to run from a position outside the depression annularly surrounding the spike and so as to be aligned in the direction of the depression annularly surrounding the spike, and so as to extend as far as the depression annularly surrounding the spike. Said channel-like depressions make it possible, in particular during long slipping movements (for example during braking/under traction without ABS or traction control), to ensure that the ice particles are reliably expelled from the reservoir under the profile block into the nearest

- 8 -transverse groove, and to thereby ensure optimized spike engagement.
Particularly advantageous is an embodiment of a tread profile, wherein the rubber material which is delimited between two adjacent channel-like depressions and which extends in the radial direction R of the tire as far as the envelope surface forms, in an elongation extending into the depression annularly surrounding the spike, a rib which is radially elevated from the depression base and which extends as far as the spike and which supports the latter in particular in the circumferential direction U of the tire. This permits a reliable supporting action of the spike. Tilting of the spike out of its optimum spike engagement angle under load can be hindered in this way. Ice engagement can thereby be further improved.
Particularly advantageous is an embodiment of a tread profile, wherein a radially outwardly extending sealing lip is formed on the envelope surface directly adjacent to the depression along the outer contour line. In this way, the natural edge effect of the depression can be increased, and therefore the chipped-away ice particles can be even more effectively prevented from passing into the tire-ice contact area.
Particularly advantageous is an embodiment of a tread profile, wherein, on the envelope surface, in the rib which is radially elevated from the depression base, a radially outwardly extending sealing lip is formed in each case directly adjacent to the adjoining depression - and in particular also as an elongation of the delimiting channel-like depression - along the extent of the rib. In this way, an escape of the chipped-away ice particles from the channel-like depressions can be prevented, and said ice particles can furthermore be s , - 8a -prevented from passing into the tire-ice contact area, as a result of which a large rubber-ice frictional contact area and good ice performance can be ensured.
The invention will be explained in more detail below on the basis of the exemplary embodiments illustrated in figures 1 to 7, in which:
figure 1 shows a plan view of a profile block element of a tread profile of a pneumatic vehicle tire, with a spike mounted thereon, figure 2 shows the profile block element of figure 1 in a sectional illustration as per section II-II in figure 1, figure 3 shows the profile block element of figure 1 in a sectional illustration as per section III-III in figure 1, figures 4a to 4d: show different alternative outer contours of the depression which is formed in a profile block element of figures 1 to 3 and which surrounds the spike, figure 5a shows a plan view of a profile block element as per figure 1 having a depression, which surrounds the spike, with a circular outer contour line, ,

- 9 -figure 5b shows a cross section through said profile block element as per section Vb-Vb in figure 5a, and figure 5c shows a cross section through an embodiment of the depression as per section Vc-Vc in figure 5a, figure 6 shows a simplified plan view of a profile block element as per the illustration of figure 1 for explaining an embodiment with alternatively designed expulsion channels, figure 7 shows a plan view of the tread profile of a spiked tire with spikes and depressions formed as per figure 1 to figure 3.
Figures 1 to 3 show a profile block element 1 of a tread profile of a pneumatic vehicle tire for passenger motor vehicles, which profile block element, in a known way, is delimited in the circumferential direction U of the pneumatic vehicle tire in each case by a transverse groove 2 arranged in front of the profile block element 1 and by a transverse groove 2 arranged behind the profile block element 1, and is delimited in the axial direction A of the pneumatic vehicle tire to both axial sides in each case by a circumferential groove 3 and a circumferential groove 4. The profile block element 1 is delimited in the radial direction R of the pneumatic vehicle tire by a surface 8 which forms the envelope surface of the pneumatic vehicle tire and which forms the ground contact surface.
In the profile block element 1, a spike 5 having a spike body 6 which has a cylindrical envelope surface and having a spike pin 7 is fastened in a spike hole.
The spike body 6 extends outward in the radial direction as far as the surface, which forms the envelope surface 8, of the profile block element 1. The spike pin 7 which is fastened in the spike body 6 extends in the radial direction R of the pneumatic

- 10 -vehicle tire through the spike body 6 and as far as a position radially outside the envelope surface 8.
The spike body 6 is formed with an outer diameter of 5.5 mm D 7.5 mm.
Formed around the spike body 6 in the radially outer envelope surface 8 of the profile block element is an annular depression 9 which, at the side pointing toward the spike 5, is delimited by the envelope surface 10 of the spike 5, and at the side pointing away from the spike 5, is delimited by a wall, which forms the outer contour line 11 of the depression 9, of the depression. The depression 9 which forms a receiving reservoir for scratched-away ice extends over the circumference of the spike 5.
In one exemplary embodiment - illustrated in figures 1 to 3 - there are formed in the envelope surface 8 of the profile block element 1 two guide channels 12 and 13 which extend from a transverse groove 2, which run rectilinearly in the direction of the spike 5 and which extend as far as the depression 9. Likewise formed in the envelope surface 8 of the profile block element 1 are two guide channels 14 and 15 which extend from the other transverse groove 2, which in each case run rectilinearly in the direction of the spike 5 and which extend as far as the depression 9. The guide channels 12, 13, 14 and 15 are formed in each case with the same width BIC, which is constant over their respective extents, of 1 mm BK 5 mm - for example 1 mm BK 5 mm - and with the same depth TK, constant over the entire profile and measured in the radial direction, of 0.5 mm TK 1.5 mm. In an exemplary embodiment, the width BK is 1.5 mm and the depth TK is 0.8 mm.
Figures 1 to 3 show a further exemplary embodiment in which the rubber material, formed in each case between the two guide channels 12 and 13, and the rubber material, formed in each case between the two guide

- 11 -channels 14 and 15, of the profile block element 1, which is delimited outward in the radial direction R by the envelope surface 8, is formed so as to extend through the depression 9 as far as the spike body 6, and forms a stiffening rib 16 or 17 which stiffens the spike body 6 and therefore the spike 5 in the circumferential direction U of the pneumatic vehicle tire. In this case, the two narrow stiffening ribs 16 and 17 divide the annular depression 9 into circumferential segments of the depression 9. The stiffening rib 16 and the stiffening rib 17 are formed - as can be seen in figure 1 - with a width, measured in the axial direction A of the pneumatic vehicle tire, which narrows proceeding from the respective transverse groove 2 in the direction of the spike 5.
In the abovementioned exemplary embodiments, the depression 9 is formed, over its entire range of extent in the radial direction R1 with respect to the spike axis S and over its entire range of circumferential extent around the spike axis S, with a constant depth T, measured proceeding from the envelope surface 8 in the radial direction R of the pneumatic vehicle tire, of 0.5 mm T 1 mm, for example T = 0.5 mm.
Figures 1 to 3 show a further exemplary embodiment in which, on the radially outwardly pointing envelope surface 8 which forms the ground contact surface, a sealing lip 18 which is directed radially outward out of the envelope surface 8 which forms the ground contact surface is formed along the outer contour line 11 of the depression 9 between the guide channels 13 and 14 and between the guide channels 12 and 15, and in each case directly adjacent to the outer contour line 11. Figures 1 to 3 furthermore show an exemplary embodiment in which, in addition, on the radially outwardly pointing envelope surface 8 which forms the ground contact surface, the stiffening rib 16 and the

- 12 -stiffening rib 17 are each formed, along their flank pointing in each case toward the guide channel 13, 12 and 14, 15 respectively, with a sealing lip 19 directed radially outward out of the envelope surface 8 which forms the ground contact surface, which sealing lip extends in each case directly adjacent to the guide channel 12, 13 and 14, 15, which delimits the respective rib 16 and 17, and along the direction of extent of the respective guide channel 12, 13 and 14, 15 between the transverse groove 2 and spike 5. The sealing lips 18 and 19 are formed with a height extent H measured radially outward from the radially outer envelope surface which forms the ground contact surface, and with a maximum width Bw measured in each case perpendicular to the direction of extent of the respective sealing lip 18 or 19, on the envelope surface 8 which forms the radially outer surface is formed, and have a V-shaped cross-sectional contour -as shown in figure 2 on the basis of the sealing lip 18 as an example - in cross section with respect to the direction of extent of the respective sealing lip 18 or 19, wherein the tip of the V-shape delimits the respective sealing lip 18 or 19 in the radially outward direction. Here, the height H is 0.3 mm and the width Bw is 0.5 mm. In figure 1, the outer contour line 11 of the depression 9 is circular and formed concentrically with respect to the spike axis S.
In another, alternative design, the outer contour line 11 is oval or elliptical.
Figures 4a to 4d show further alternative embodiments of the outer contour line 11 of the depression with a polygonal profile. In figures 4a to 4d, for the sake of simplicity, the spike and the profile block element have been omitted from the illustration and only the outer contour line 11 of the depression 9 is shown.
Here, the outer contour line is, for example, in the

- 13 -form of a rhombus as illustrated in figure 4a, in the form of a parallelogram as illustrated in figure 4b, for example triangular as illustrated in figure 4c, or star-shaped with a jagged contour line 11 as illustrated in figure 4d.
In the case of such a polygonal design, guide channels 12 open into the depression 9 within the rectilinear path between adjacent corner points of the outer contour line 11, as illustrated in simplified form in figure 4a and figure 4d, or at corner points of the polygonal structure, as shown in the exemplary embodiment of figure 4b.
Figures 5a and 5b show an exemplary embodiment on the basis of a depression 9 with a circular contour line 11 as an example, in which the depression base 26 which delimits the depression 9 radially to the inside in the radial direction R of the pneumatic vehicle tire rises linearly, in terms of its position measured in the radial direction R of the pneumatic vehicle tire, in the radial direction R1 toward the spike axis proceeding from the outer contour line 11 of the depression 9. In the embodiment shown, the depth T of the depression 9 decreases continuously in the direction of the spike body 6 proceeding from its maximum value at the outer contour 11 of the depression.
Figures 5a, 5b and 5c show a further exemplary embodiment in which the depth T additionally varies continuously over the circumference of the spike. It can be seen here that, in the section through the spike axis S in the circumferential direction U of the pneumatic vehicle tire as illustrated in figure 5c, the maximum depth T measured at the outer contour 11 of the depression 9 is smaller than that in the section through the spike axis S in the axial direction A of the pneumatic vehicle tire as illustrated in figure 5b.

, ,

- 14 -The depth T is formed so as to vary in each case continuously between said two extremes along the circumferential extent of the depression around the spike axis S.
In another embodiment which is not illustrated, in the section planes encompassing the spike axis S, the minimum depth T of the depression 9 is formed in the region of the outer contour line 11 and the maximum depth T is formed at the envelope surface of the spike body 6.
Figure 6, on the basis of an example of a depression 9 with an oval contour line 11, illustrates an embodiment with a plurality of guide channels 12 and 13 and with a guide channel 14. The guide channels 12 are rectilinear with a constant channel width BK. The guide channels 13 are curved with a constant channel width BK, and the guide channel 14 is formed so as to be rectilinear with a channel width BK which increases continuously in the direction away from the spike proceeding from the depression 9.
In another embodiment which is not illustrated, at least one channel 12 is formed with a depth T which varies continuously - for example which increases continuously in the direction away from the spike -along its extent.
In the embodiment illustrated in figures 1 to 3, TK> T.
TK = 0.8 mm, and T = 0.5 mm.
In another embodiment (not illustrated) of the embodiment illustrated in figures 1 to 3, the depth TK
of the channels 12, 13, 14, 15 is selected to be equal to the depth T of the depression 9, that is to say T =
TK.

,

- 15 -Figure 7 shows the use of an embodiment as per figure 1 with a spike 5, with a depression 9, with guide channels 12, 13, 14 and 15 and with sealing lips 18 and 19 in profile block elements 1 of a profile block row 20 of a tread profile having a plurality of profile block rows 21, 22, 23, 20 and 24 which are arranged adjacent to one another in the axial direction A of a pneumatic vehicle tire and which are separated from one another in each case by circumferential grooves. Figure 7 furthermore shows an exemplary embodiment in which such spikes 5 with a depression 9 and with an outer contour line 11 and with guide channels 12, 13, 14 and and with stiffening ribs 16 and 17 and with sealing lips 18 and 19 are also formed analogously in 15 individual profile block elements in other profile block rows 21, 22 and 24.
The profile block elements of the different profile block rows 21, 22, 23, 20 and 24 are in each case provided, in a known way, with sipes 25.

,

- 16 -List of reference numerals (Part of the description) 1 Profile block element 2 Transverse groove 3 Circumferential groove 4 Circumferential groove 5 Spike 6 Spike body . 7 Spike pin 8 Envelope surface 9 Depression (receiving reservoir) 10 Envelope surface of the spike 11 Outer contour of the depression 12 Guide channel 13 Guide channel 14 Guide channel 15 Guide channel 16 Stiffening rib

17 Stiffening rib

18 Sealing lip

19 Sealing lip

20 Profile block row

21 Profile block row

22 Profile block row

23 Profile block row

24 Profile block row

25 Sipe

26 Depression base

Claims

claims

1. A tread profile of a pneumatic vehicle tire, having a plurality of radially elevated profile elements (1) which are spaced apart from one another by grooves (2, 3, 4) or furrows and which are in each case delimited outward in the radial direction R by an envelope surface (8) which forms the ground contact surface, wherein in at least one profile element (1) there is formed at least one spike (5) which is anchored with its spike body (6) in the rubber material of the profile element (1) and which is formed with a spike tip, which spike tip extends out of the spike body (6) in the radial direction R of the tire and ends at a radial position outside the envelope surface (8), which delimits the profile element (1) radially to the outside and which forms the ground contact surface, of the profile element (1), characterized in that, in the envelope surface (8) which delimits the profile element (1) radially to the outside and which forms the ground contact surface, there is formed a depression (9) which serves for receiving ice and which substantially annularly surrounds the spike (5), wherein the depression (9) in the envelope surface (8) is delimited by an outer contour line (11) which delimits the depression at the side positioned away from the spike (5), and is delimited on the side positioned toward the spike (5) by said spike (5).

2. The tread profile as per the features of claim 1, wherein the spike body (6) has a cylindrical envelope surface (10) with a cross section of said envelope surface (10) formed perpendicular to the cylinder axis, which cross section is formed with a maximum outer diameter D of 5.5 mm <= D <= 7.5 mm, wherein the spike body (6) has in particular a round cylindrical envelope surface (8).

3. The tread profile as per the features of claim 1 or 2, wherein the depression (9) in the envelope surface (8) has a width F measured in the radial direction R1 with respect to the spike axis S, the value of said width being 2 mm <= F <= 10 mm over its extent over the circumference of the spike (5).

4. The tread profile as per the features of any one of claims 1 to 3, wherein the depression (9) is formed with a depth T, measured in the radial direction R of the tire from the envelope surface (8) to the depression base (26), of 0.5 mm <= T <= 1 mm.

5. The tread profile as per the features of claim 4, wherein the depth T of the depression (9) is formed so as to increase continuously - in particular linearly - toward the spike axis S in the radial direction R1.

6. The tread profile as per the features of any one of claims 1 to 5, wherein the depression (9) in the envelope surface (8) is formed with an outer contour line (11) which delimits the depression (9) at the side positioned away from the spike (5) and which has a curved profile.

7. The tread profile as per the features of claim 6, wherein the outer contour line (11) is of circular, oval or elliptical form.

8. The tread profile as per the features of any one of claims 1 to 5, wherein the depression (9) in the envelope surface (8) is formed with an outer contour line (11) which delimits the depression at the side pointing away from the spike (5) and which has a polygonal - in particular star-shaped serrated - profile.

9. The tread profile as per the features of any one of claims 1 to 8, wherein in the envelope surface (8) which delimits the profile element (1) radially to the outside, there are additionally formed one or more channel-like depressions (12, 13, 14, 15) with a width B K
of 1 mm <= B K <= 5 mm and with an - in particular constant - depth T K of 0.5 mm <= T K <= 1.5 mm, which channel-like depressions are formed so as to run from a position outside the depression (9) annularly surrounding the spike (5) and so as to be aligned toward the depression (9) annularly surrounding the spike (5), and so as to extend as far as the depression (9) annularly surrounding the spike (5).

10. The tread profile as per the features of claim 9, wherein the rubber material which is delimited between two adjacent channel-like depressions (12, 13) and which extends in the radial direction R of the tire as far as the envelope surface (8) forms, in an elongation extending into the depression (9) annularly surrounding the spike (5), a rib (16) which is radially elevated from the depression base (26) and which extends as far as the spike (5) and which supports the latter in particular in the circumferential direction U of the tire.

11. The tread profile as per the features of any one of claims 1 to 10, wherein a radially outwardly extending sealing lip (18) is formed on the envelope surface (8) directly adjacent to the depression (9) along the outer contour line (11).

12. The tread profile as per the features of claim 10 or 11, wherein, on the envelope surface (8), in the rib (16) which is radially elevated from the depression base (26), a radially outwardly extending sealing lip (19) is formed in each case directly adjacent to the adjoining depression (9) along the extent of the rib (16).

13. The tread profile as per the features of claim 12, wherein the radially outwardly extending sealing lip (19) is formed as an elongation of the delimiting channel-like depression (12 or 13).