COMMERCIAL VEHICLE TYRE

Abstract

The invention relates to a commercial vehicle tire having a tread with at least one profile rib which runs in encircling fashion in a circumferential direction, is arranged laterally with respect to the tire equatorial plane and has sipes extending through it, which sipes each have sipe walls, a sipe midplane spaced apart equally from the sipe walls, a width of 0.4 mm to 2.0 mm and a maximum depth in a radial direction of at least 40% of the profile depth, wherein each sipe, at least in a portion which runs over the predominant part thereof as seen in plan view, has at least one sipe zone which is offset in relation to the radially outer sipe periphery and which runs in an extent direction of the sipe in an undulating form and in arcuate or singly serrated form in a radial direction, wherein a plane running through the point of the maximum excursion of the sipe zone has a line of intersection with the sipe midplane, which line of intersection follows the undulating form of the sipe zone.

The sipe runs in the undulating form exclusively in the sipe zone, wherein the amplitude of the line of intersection that follows the undulating form of the sipe zone decreases, in each line-of-intersection portion running over one half of a wavelength, in the direction of the tread-outside sipe end.

Claims

1-15. (canceled)

16. A commercial vehicle tire comprising: a shoulder side profile rib that runs in encircling fashion in a circumferential direction, is arranged laterally with respect to a tire equatorial plane and has a plurality of sipes extending through it; the sipes each have sipe walls, a sipe midplane spaced apart equally from the sipe walls, a width (b.sub.E) of 0.4 mm to 2.0 mm and a maximum depth (t.sub.E) in a radial direction; the maximum depth is at least 40% of the profile depth (T.sub.P); each sipe of the plurality of sipes has at least one sipe zone which is offset in relation to the radially outer sipe periphery and which runs in an extent direction of the sipe in an undulating form and in arcuate or singly serrated form in a radial direction; a plane (F.sub.1) runs through a point of the maximum excursion of the sipe zone and has a line of intersection (l.sub.1) with a sipe midplane (f.sub.E), the line of intersection follows the undulating form of the sipe zone; wherein a sipe of the plurality of sipes runs in the undulating form exclusively in the sipe zone, wherein the amplitude of the line of intersection (l) that follows the undulating form of the sipe zone decreases, in each line-of-intersection portion running over one half of a wavelength (?/2), in the direction of a tread-outside sipe end.

17. The tire of claim 16, wherein the amplitude has a first amplitude value (A.sub.i) at the tread-inside end of each line-of-intersection portion (l.sub.1) and has a second amplitude value (A.sub.i+1) at the tread-outside end of each line-of-intersection portion (l.sub.1), wherein each second amplitude value (A.sub.i+1) is 0.60 times to 0.95 times the associated first amplitude value (A.sub.i).

18. The tire of claim 16, wherein the amplitude (A.sub.1) at the tread-inside end of that line-of-intersection portion (l.sub.1) which is furthest to the inside of the tread has an amplitude value (A.sub.1) of 100% to 500% of the width (b.sub.E) of the sipe (12).

19. The tire of claim 16, wherein the line of intersection (l.sub.1) that follows the undulating form of the sipe zone (12) runs over three to six wavelengths (?).

20. The tire of claim 16, wherein the wavelengths (?) are of equal size.

21. The tire of claim 16, wherein the plane (F.sub.1) that runs through the point of the maximum excursion of the sipe zone (12) runs parallel to the rib outer surface (1a) of the profile rib (1).

22. The tire of claim 16, wherein the plane (F.sub.1) that runs through the point of the maximum excursion of the sipe zone (12) is a plane of symmetry (F.sub.1) of the sipe zone (12).

23. The tire of claim 16, wherein the plane (F.sub.1) that runs through the point of the maximum excursion of the sipe zone (12) runs, at least over the predominant part of its extent, at a constant depth (t.sub.F), measured in a radial direction, of 45% to 65%, in particular of 50% to 60%, of the maximum depth (t.sub.E) of the sipe (12).

24. The tire of claim 16, wherein the line of intersection (l.sub.1) that follows the undulating form of the sipe zone (12) runs in the form of a zigzag-shaped undulation.

25. The tire of claim 16, wherein as viewed in a cross section of the sipe (12), the sipe zone (12) has a length (l), based on the sipe midplane (f.sub.E) and measured in a radial direction, of 30% to 90%, in particular of 35% to 80%, of the maximum depth (t.sub.E) of the sipe (12).

26. The tire of claim 16, wherein the sipe (12) has a radially outer sipe portion (12) which runs in a straight manner between the sipe zone (12) and the sipe periphery and in the cross section of the sipe (12) and which has a length (l), based on the sipe midplane (f.sub.E), of preferably 0.5 mm to 1.5 mm.

27. The tire of claim 16, wherein the sipe (12) has a radially inner sipe portion (12) which adjoins the sipe zone (12) and which runs in a straight manner in the cross section of the sipe (12) and which has a length (l), based on the sipe midplane (f.sub.E), of preferably 0.5 mm to 1.5 mm.

28. The tire of claim 16, wherein the sipes (12) include sipes (12) a) which proceed from the rib outer surface (1a) of the profile rib (1) and/or b) which are each situated in a profile rib web (8) which belongs to the profile rib (1) and which is formed in a transverse channel (3) extending through the profile rib (1), wherein the profile rib web (8) extends over the predominant part of the transverse channel (3) and has a top surface (8a) which, in relation to the rib outer surface (1a) of the profile rib (1), preferably runs at a depth (t.sub.a), measured at the lowest point(s) of said top surface in a radial direction, of 1.0 mm to 10.0 mm, in particular of 2.0 mm to 5.0 mm, and/or c) which each proceed from the base of a depression extending through the profile rib (1), wherein the depression has a depth of 1.0 mm to 10.0 mm, in particular of 2.0 mm to 5.0 mm, in a radial direction in relation to the rib outer surface (1a) of the profile rib (1).

29. The tire of claim 16, wherein the sipes (12) are provided which each, over their entire extent, open into a channel (13) which is formed in the interior of the profile rib (1) and which has a diameter (d.sub.K) of 200% to 600%, in particular of 300% to 500%, preferably of 350% to 450%, of the width (b.sub.E) of the sipe (12).

30. The tire of claim 16, wherein the profile rib (1) is a shoulder-side profile rib (1).

31. A commercial vehicle tire comprising: a shoulder side profile rib that runs in encircling fashion in a circumferential direction, is arranged laterally with respect to a tire equatorial plane and has a plurality of sipes extending through it; the sipes each have sipe walls, a sipe midplane spaced apart equally from the sipe walls, a width (b.sub.E) of 0.4 mm to 2.0 mm and a maximum depth (t.sub.E) in a radial direction; the maximum depth is at least 40% of the profile depth (T.sub.P); each sipe of the plurality of sipes has at least one sipe zone which is offset in relation to the radially outer sipe periphery and which runs in an extent direction of the sipe in an undulating form and in arcuate or singly serrated form in a radial direction; a plane (F.sub.1) runs through a point of the maximum excursion of the sipe zone and has a line of intersection (l.sub.1) with a sipe midplane (f.sub.E), the line of intersection follows the undulating form of the sipe zone; wherein a sipe of the plurality of sipes runs in the undulating form exclusively in the sipe zone, wherein the amplitude of the line of intersection (l) that follows the undulating form of the sipe zone decreases, in each line-of-intersection portion running over one half of a wavelength (?/2), in the direction of a tread-outside sipe end; wherein one or more of the plurality of sipes: proceed from a rib outer surface; and are each situated in a profile rib web of the shoulder profile rib and which is formed in a transverse channel, wherein the profile rib web extends over a predominant part of the transverse channel and has a top surface which, in relation to the rib outer surface (1a) of the profile rib, runs at a depth (t.sub.a), measured at the lowest point(s) of said top surface in a radial direction, of 1.0 mm to 10.0 mm, in particular of 2.0 mm to 5.0 mm.

32. The tire of claim 32, wherein the one or more of the plurality of sipes each proceed from the base of a depression extending through the profile rib, wherein the depression has a depth of 1.0 mm to 10.0 mm, in particular of 2.0 mm to 5.0 mm, in a radial direction in relation to the rib outer surface of the profile rib.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features, advantages and details of the invention will now be described in more detail with reference to the drawing, which schematically illustrates an exemplary embodiment of the invention. In the drawing:

[0026] FIG. 1 shows a plan view of a circumferential portion of a shoulder-side profile rib of a tread of a commercial vehicle tire, having a design variant of the invention,

[0027] FIG. 2 shows an enlarged plan view of the detail Z.sub.2 in FIG. 1,

[0028] FIG. 3 shows a view in the viewing direction indicated in FIG. 2 by the arrow S.sub.3,

[0029] FIG. 4 shows a view in the viewing direction indicated in FIG. 2 by the arrow S.sub.4,

[0030] FIG. 5 shows a visualization of a sipe in an oblique view,

[0031] FIG. 6 shows a visualization of the sipe from FIG. 5 in a plan view,

[0032] FIG. 7 shows a visualization of the sipe from FIG. 5 in a plan view, with the tread having been worn away to the level N.sub.7 indicated in FIG. 5,

[0033] FIG. 8 shows a section along the line VIII-VIII in FIG. 6,

[0034] FIG. 9 shows a plan view of a visualized sipe midplane belonging to the sipe from

[0035] FIG. 5 to FIG. 8, and

[0036] FIG. 10 shows an oblique view of the visualized sipe midplane from FIG. 9.

DETAILED DESCRIPTION

[0037] Commercial vehicle tires designed according to the invention are tires for multi-track commercial vehicles, preferably for medium-weight trucks (7.5 t<gross vehicle weight?18.0 t) or for heavy trucks (gross vehicle weight>18.0 t), and in particular commercial vehicle tires of radial construction. The commercial vehicle tires according to the invention are preferably installed on the drive axle.

[0038] FIG. 1 shows a plan view of a circumferential portion of a shoulder-side profile rib 1 of a tread of a commercial vehicle tire. A second shoulder-side profile rib, which is mirror-symmetrical with respect to the shoulder-side profile rib 1 in relation to the tire equatorial plane, is preferably formed in the second tread shoulder. The tread preferably has a directional profiling, which is intended for being installed on a commercial vehicle so as to have the rolling direction indicated in FIG. 1 by the arrow R during forward travel.

[0039] The shoulder-side profile rib 1 is delimited toward the inside of the tread by a shoulder-side circumferential channel 2, which in the exemplary embodiment shown runs in undulating fashion as seen in plan view and which, in a radial direction, is formed with the respectively provided profile depth T.sub.P (indicated in FIG. 3), normally of 12.0 mm to 26.0 mm. In the case of treads with circumferential channels of different depths, the expression profile depth refers to the depth of the deepest circumferential channel(s).

[0040] The shoulder-side profile rib 1 has a rib outer surface 1a situated at the tread periphery and is equipped with a multiplicity of shoulder-side transverse channels 3 which are distributed over the tread circumference, which run parallel to one another as seen in plan view, which are inclined relative to the axial direction and which extend through the shoulder-side profile rib 1 such that said profile rib exhibits rib elements 4. At the rib outer surface 1a, each rib element 4 has a leading edge 5a at one adjoining transverse channel 3, said leading edge entering the ground contact patch first as the tire rolls during forward travel (arrow R), has a trailing edge 5b at the other adjoining transverse channel 3, and has an edge Sc at the circumferential channel 2. As seen in plan view, the edges 5a, 5b run substantially parallel to one another, each with a scarcely perceptible S-shaped curvature, and, based on a line 1 (FIG. 2) which connects the ends of the particular edge 5a, 5b and which is straight in plan view, at an angle ? (FIG. 2) relative to the axial direction of 10? to 25?, in particular of 13? to 20?, wherein the angle ? of the edge 5a differs from the angle ? of the edge 5b by at most 3, in particular by at most 1?. Shoulder-side transverse channels 3 that directly follow one another in a circumferential direction have spacings a.sup.1 to one another of preferably 20.0 mm to 80.0 mm, in particular of 30.0 mm to 70.0 mm, based on the edges 5a, 5b and measured in the circumferential direction.

[0041] In the exemplary embodiment shown, a bevel 6a proceeds from the edge 5a and a bevel 6c proceeds from the edge Sc, wherein, as viewed in a cross section perpendicular to the associated edge 5a, Sc, the bevels 6a, 6c appear as straight lines and run at an angle of preferably 30? to 55? with respect to the radial direction, and said bevels furthermore each extend in a radial direction to a depth t.sub.f (FIG. 3) of in particular up to 3.0 mm and each have a bevel edge 7a (bevel 6a: FIG. 2 and FIG. 3), 7c (bevel 6c: FIG. 2 and FIG. 3) that runs at the depth t.sub.f.

[0042] The further configuration of the shoulder-side transverse channels 3 will be discussed below with reference to a single shoulder-side transverse channel 3.

[0043] As shown in FIG. 2, the shoulder-side transverse channel 3 has a scarcely perceptible S-shaped curvature as seen in plan view, similarly to the edges 5a, 5b. The transverse channel 3 has a width b.sub.QR, measured as a smallest possible spacing between the edges 5a, 5b, of 6.0 mm to 12.0 mm, said width either being constant over the extent of the edges 5a, 5b or varying by at most 2.0 mm, and a length l.sub.QR projected in the axial direction and based on the edges 5a, 5b, specifically on the longer of the two edges 5a, 5b in the case of edges 5a, 5b of different lengths.

[0044] A profile rib web 8 (cf. FIG. 3 and FIG. 4) is formed in the transverse channel 3, which profile rib web 8 is spaced apart from the ends of the transverse channel 3, extends over the predominant part of the length l.sub.QR of the transverse channel 3, extends to the rib elements 4, and is offset in a radial direction in relation to the rib outer surface 1a, such that the transverse channel 3, as seen in plan view, is made up of a central channel main portion 3a, which runs on the profile rib web 8, a channel mouth portion 3b adjoining the tread-inside end of the profile rib web 8, and a channel shoulder portion 3c adjoining the tread-outside end of the profile rib web 8.

[0045] The channel mouth portion 3b and the channel shoulder portion 3c are, as seen in cross section, each delimited by a base 9b (channel mouth portion 3b, cf. FIG. 3), 9c (channel shoulder portion 3c, cf. FIG. 4) and by flanks 9d (cf. FIG. 3 and FIG. 4) formed on the rib elements 4, with in each case one flank 9d running to the bevel edge 7a (FIG. 2 to FIG. 4) and the other flank 9d running to the trailing edge 5b (FIG. 2 and FIG. 4).

[0046] As is also shown in FIG. 2, the profile rib web 8 is delimited in a radial direction by a top surface 8a running parallel to the rib outer surface 1a, toward the channel mouth portion 3b by a tread-inside side flank 8b (see FIG. 3) running in the direction of the base 9b, and toward the channel shoulder portion 3c by a tread-outside side flank 8c (cf. FIG. 4) running in the direction of the base 9c. The top surface 8a runs, in relation to the rib outer surface 1a (FIG. 4), at a depth t.sub.a, measured at the lowest point(s) of said top surface in a radial direction, of 1.0 mm to 10.0 mm, in particular of 2.0 mm to 5.0 mm. The side flanks 8b, 8c run in a radial direction or at an angle of up to 3? relative to the radial direction, and in the exemplary embodiment shown are surfaces which have a slight curvature over their entire extent and which indent the end regions of the profile rib web 8 and which transition continuously (without sharp angles) into the flanks 9d of the channel mouth portion 3b and the flanks 9d of the channel shoulder portion 3c (FIG. 2 to FIG. 4) respectively. Furthermore, in the exemplary embodiment shown, between the top surface 8a and each adjoining rib element 4, there is formed a rounded transition portion 10 (FIG. 2 to FIG. 4) which extends from the tread-inside side flank 8b (FIG. 3) to the tread-outside side flank 8c (FIG. 4) and adjoins these in continuous fashion (without sharp angles). Further rounded transition portions 11 (FIG. 2 to FIG. 4) are formed between the ends of the top surface 8a and the side flanks 8b, 8c.

[0047] As per FIG. 2, the profile rib web 8 has a length l.sub.S, based on the furthest spaced-apart ends of its top surface 8a and projected in the axial direction, of 50% to 80%, in particular of 65% to 75%, of the length l.sub.QR of the transverse channel 3, and is provided with a sipe 12 which proceeds from the center of the top surface 8a, which runs in a radial direction into the interior of the profile rib web 8, which extends through the profile rib web 8 over the longitudinal extent thereof, and which in the exemplary embodiment opens, over its entire extent, into a tubular channel 13 (cf. FIG. 5) formed in the interior of the profile rib web 8. Both the sipe 12 and the channel 13 therefore emerge from the profile rib web 8 at the side flanks 8b, 8c, with the sipe 12 furthermore emerging at the rounded transition portions 11.

[0048] As shown in FIG. 5, FIG. 6 and FIG. 8, the sipe 12 has two mutually opposite sipe walls 12a and a constant width b.sub.E (FIG. 8), measured between and perpendicular to the sipe walls 12a, of 0.4 mm to 2.0 mm, in particular of up to 1.2 mm, preferably of up to 0.8 mm, and, over the predominant part of its extent, extends in a radial direction to a maximum depth t.sub.E (FIG. 3, depth at the lowest point), measured in relation to the level of the rib outer surface 1a, of 40% to 90%, in particular of 50% to 80%, of the profile depth T.sub.P (FIG. 3). The sipe 12 becomes narrower in the direction of the tread shoulder, in a manner known per se.

[0049] The sipe 12 has a sipe centerline m.sub.E (FIG. 6), which as seen in plan view follows the sipe profile present at the top surface 8a, a sipe midplane f.sub.E (FIG. 8), which proceeds from said sipe centerline and which is spaced apart equally from the sipe walls 12a, a tread-inside sipe end 12b (FIG. 6) and a tread-outside sipe end 12c (FIG. 6), and, as seen in cross section as shown in FIG. 8, said sipe is made up in a radial direction of a radially outer sipe portion 12 (scarcely visible in FIG. 8), a middle sipe zone 12 which runs in arcuate or singly serrated form (that is to say in the present case in a V shape), and a radially inner sipe portion 12.

[0050] The radially outer sipe portion 12 and the radially inner sipe portion 12 run in a radial direction and as a continuation of one another (in alignment), and have respective lengths l (sipe portion 12) and l (sipe portion 12), based on the sipe midplane f.sub.E and measured in a radial direction, of preferably 0.5 mm to 1.5 mm in each case.

[0051] The middle sipe zone 12 is thus offset in a radial direction relative to the level of the radially outer sipe periphery that is present at the top surface 8a (level of the sipe edges), that is to say into the interior of the profile rib web 8. The middle sipe zone 12 runs in an extent direction of the sipe 12 in an undulating form (FIG. 6) and has a length l (FIG. 8), based on the sipe midplane f.sub.E and measured in a radial direction, of 30% to 90%, in particular of 35% to 80%, of the maximum depth t.sub.E (FIG. 3). In the direction of the outside of the tread, the length l preferably decreases by 10% to 30% in relation to its particular maximum value (cf. FIG. 10).

[0052] As can be seen from FIG. 8 in particular in combination with FIG. 5, the middle sipe zone 12 furthermore has a plane of symmetry F.sub.1 (indicated in FIG. 5 by the level N.sub.7), which is oriented parallel to the rib outer surface 1a and which runs through the point of the maximum excursion of the middle sipe zone 12 and, at least over the predominant part of its extent, at a constant depth t.sub.F (FIG. 8), measured in a radial direction, of 45% to 65%, in particular of 50% to 60%, of the maximum depth t.sub.E(FIG. 3). The point of the maximum excursion of the middle sipe zone 12 is defined by that point of the sipe midplane f.sub.E which has the greatest excursion in relation to the sipe centerline m.sub.E as seen in the cross section which, in plan view, is oriented perpendicular to the sipe centerline m.sub.E.

[0053] FIG. 9 and FIG. 10 each show the sipe midplane f.sub.E of the sipe 12. In FIG. 9, the sipe midplane f.sub.E has a line of intersection l.sub.1 with the plane of symmetry F.sub.1 (FIG. 8), which line of intersection, as seen in plan view, runs in a zigzag-shaped undulation over the aforementioned length l.sub.S (cf. FIG. 2), projected in the axial direction, of the profile rib web 8. The line of intersection l.sub.1 thus follows the undulating form of the middle sipe zone 12. As shown in FIG. 7, the middle sipe zone 12 is thus formed by shallow pyramid-shaped projections 14, which are formed correspondingly alternately on the sipe walls 12a and each have a rectangular, in particular square, base lying on the particular sipe wall 12a (cf. the visualization in FIG. 10), and depressions 15 which are situated opposite, and correspond with, the projections 14.

[0054] The profile of the line of intersection l.sub.1 will hereinafter be discussed with the aid of an undulation baseline l.sub.b (FIG. 9) that runs in the plane of symmetry F.sub.1. The undulation baseline l.sub.b is obtained by projecting the sipe centerline m.sub.E (FIG. 6) into the plane of symmetry F.sub.1 (FIG. 8) and is the line in relation to which the amplitude of the undulation is measured in a known manner. As per FIG. 9, the line of intersection l.sub.1 running in undulating fashion extends over three to six, preferably over up to five, in the exemplary embodiment over four, wavelengths ?, which in the exemplary embodiment are of equal size. Furthermore, the line of intersection l.sub.1 running in undulating fashion has a varying amplitude which decreases, over each line-of-intersection portion l.sub.1 (two of these are labeled in FIG. 9) running over one half of a wavelength ?/2, in the direction of the tread-outside sipe end 12c. The decrease in amplitude thus takes place in each case from the tread-inside end of a line-of-intersection portion l.sub.1, which is situated closer to the tread-inside sipe end 12b, to the tread-outside end of said line-of-intersection portion l.sub.1, which is situated closer to the tread-outside sipe end 12c. At the tread-inside end of that line-of-intersection portion l.sub.1 which is furthest to the inside of the tread, the amplitude has an amplitude value A.sub.1. At the tread-outside end of that line-of-intersection portion l.sub.1 which is furthest to the inside of the tread, the amplitude has an amplitude value A.sub.2 (A.sub.2<A.sub.1), which is thus also simultaneously present at the tread-outside end of the next line-of-intersection portion l.sub.1. This decrease in amplitude progresses over the further line-of-intersection portions l.sub.1, such that, in the exemplary embodiment, the amplitude has the following amplitude values in succession proceeding from the tread-inside end of that line-of-intersection portion l.sub.1 which is furthest to the inside of the tread to the tread-outside end of that line-of-intersection portion l.sub.1 which is furthest to the outside of the tread: A.sub.1-A.sub.2-A.sub.3-A.sub.4-A.sub.5-A.sub.6-A.sub.7-A.sub.8. The amplitude value A.sub.1 is 100% to 500%, in particular 120% to 300%, preferably 150% to 250%, of the width b.sub.E (FIG. 8) of the sipe 12. For the further amplitude values A.sub.i+1, the following applies: A.sub.i+1=A.sub.i*0.60 to A.sub.i*0.95 (in the exemplary embodiment, i=1 to 7). It is thus for example the case that the amplitude value A.sub.2 is 60% to 95% of the amplitude value A.sub.1, and the amplitude value A.sub.3 is 60% to 95% of the amplitude value A.sub.2.

[0055] As per FIG. 8, the aforementioned channel 13 has a circular cross section with a diameter d.sub.K of 200% to 600%, in particular of 300% to 500%, preferably of 350% to 450%, of the width b.sub.E of the sipe 12, and is designed such that the sipe 12, over its entire extent, opens centrally into said channel (FIG. 6), such that the channel 13 has a channel axis running through its center and parallel to the sipe centerline m.sub.E(FIG. 6).

[0056] The invention is not limited to the exemplary embodiment described.

[0057] The channel 13 is optional. The tread may also be of non-directional design.

[0058] The sipes 12 run at an angle of 0? to 50? with respect to the axial direction and may have a straight, arcuate or curved profile as seen in plan view. In the case of sipes 12 which run in straight fashion as seen in plan view, the angle relates to the sipe centerline; otherwise, the angle relates to a line which is straight in plan view and which connects the ends of the sipe centerline. The sipes 12 are situated in at least a profile rib which is formed laterally with respect to the tire equatorial plane and which runs in encircling fashion in a circumferential direction (not in a central profile rib that is bisected by the tire equatorial plane). Here, the sipes 12 may proceed in each case directly from the rib outer surface 1a, in each case from a base of a shallow depression which is formed in the profile rib and which is open to the tread periphery and which has a depth, measured at the lowest point(s) of said depression in a radial direction, of 1.0 mm to 10.0 mm, preferably of 2.0 mm to 5.0 mm, or from a profile rib web situated in a transverse channel, wherein the sipes extend through the profile rib or through the profile rib webs belonging to said profile rib. The aforementioned variants may also be combined with one another as desired. The sipe zones are provided at least in a portion of the sipe that runs over the predominant part of the sipe. The form of the undulation that is present in the extent direction of the sipe in the sipe zone may vary, such that the form of the undulation is, as described, a zigzag-shaped undulation, alternatively a sawtooth-shaped undulation, or a rounded undulation, for example a sinusoidal undulation.

LIST OF REFERENCE DESIGNATIONS

[0059] 1 . . . Shoulder-side profile rib [0060] 1a . . . Rib outer surface [0061] 2 . . . Shoulder-side circumferential channel [0062] 3 . . . Shoulder-side transverse channel [0063] 3a . . . Central channel main portion [0064] 3b . . . Channel mouth portion [0065] 3c . . . Channel shoulder portion [0066] 4 . . . Rib element [0067] 5a . . . Leading edge [0068] 5b . . . Trailing edge [0069] 5c . . . Edge [0070] 6a . . . Bevel [0071] 6c . . . Bevel [0072] 7a . . . Bevel edge [0073] 7c . . . Bevel edge [0074] 8 . . . Profile rib web [0075] 8a . . . Top surface [0076] 8b . . . Tread-inside side flank [0077] 8c . . . Tread-outside side flank [0078] 9b . . . Base [0079] 9c . . . Base [0080] 9d . . . Flank [0081] 10 . . . Rounded transition portion [0082] 11 . . . Rounded transition portion [0083] 12 . . . Sipe [0084] 12a . . . Sipe wall [0085] 12b . . . Tread-inside sipe end [0086] 12c . . . Tread-outside sipe end [0087] 12 . . . Radially outer sipe portion [0088] 12 . . . Middle sipe zone [0089] 12 . . . Radially inner sipe portion [0090] 13 . . . Channel [0091] 14 . . . Projection [0092] 15 . . . Depression [0093] a.sub.1 . . . Spacing [0094] A.sub.i, i=1 to 8 . . . Amplitude value [0095] b.sub.E, b.sub.QR . . . Width [0096] d.sub.K . . . Diameter [0097] f.sub.E . . . Sipe midplane [0098] F.sub.1 . . . Plane of symmetry [0099] l . . . Line [0100] l.sub.1 . . . Line of intersection [0101] l.sub.1 . . . Line-of-intersection portion [0102] l.sub.b . . . Undulation baseline [0103] l.sub.S, l.sub.QR, l, l, l . . . Length [0104] m.sub.E . . . Sipe centerline [0105] N.sub.7 . . . Level [0106] R . . . Arrow (rolling direction) [0107] S.sub.3, S.sub.4 . . . Arrow (viewing direction) [0108] t.sub.a, t.sub.E, t.sub.f, t.sub.F . . . Depth [0109] T.sub.P . . . Profile depth [0110] Z.sub.2 . . . Detail [0111] ? . . . Angle [0112] ? . . . Wavelength