Vehicle tire

Abstract

The tread profile of a vehicle tire has a circumferential rib. Grooves are formed in the circumferential rib with a width, which increases along its entire extent, wherein the grooves are formed with a vertex point between a first portion and a second portion. The groove direction from the beginning to the vertex point is formed with a greater directional component in the circumferential direction than in the axial direction and between the vertex point and the entry into the circumferential groove is formed with a greater directional component in the axial direction than in the circumferential direction. The groove is formed in the first portion with a depth T.sub.1, which increases continuously from the beginning over the first portion up to reaching its maximum value T.sub.1max at the vertex point and is formed with a constant depth T.sub.2 in the second portion wherein T.sub.2≥T.sub.1max.

Claims

1. A tread profile of a pneumatic vehicle tire, the tread profile comprising: at least one circumferential rib bounded outwardly in a radial direction R by a radially outer surface and in an axial direction A by a first circumferential groove and a second circumferential groove; said radially outer surface forming a ground contact surface; said at least one circumferential rib having transversely running transverse grooves formed therein; wherein said transverse grooves extend in the axial direction A from a beginning of extent of the corresponding transverse groove, formed at an axial distance from said first circumferential groove and said second circumferential groove, in the direction of said first circumferential groove over a first portion of extent and over a second portion of extent, which adjoins said first portion of extent in the axial direction A, and said transverse grooves open into said first circumferential groove; said transverse grooves each being formed with a width b, which is measured in said radially outer surface and increases along its entire extent between said beginning of extent and said first circumferential groove; said transverse grooves being formed in the course of their extent between said first portion of extent and said second portion of extent with a vertex point; said transverse grooves each defining a direction of extent; said direction of extent of each of said transverse grooves from said beginning of extent along their extent in said first portion of extent to said vertex point being formed with a greater directional component in the circumferential direction U than in the axial direction A and from said vertex point over the entirety of said second portion of extent up to an opening into said first circumferential groove being formed with a greater directional component in the axial direction A than in the circumferential direction; said transverse grooves being formed in said first portion of extent with a depth T.sub.1, which is formed as increasing continuously from said beginning of extent along the extent over said first portion of extent up to reaching a maximum value T.sub.1max at said vertex point and being formed with a constant depth T.sub.2 where T.sub.2≥T.sub.1max in the second portion of extent.

2. The tread profile of claim 1, wherein: said transverse grooves are formed along their extent up to said first circumferential groove following after said second portion of extent with a third portion of extent; said third portion of extent extends up to said first circumferential groove; said transverse grooves are formed with a constant depth T.sub.3 in the third portion of extent; and, wherein T.sub.2>T.sub.3.

3. The tread profile of claim 2, wherein said transverse grooves are foamed along their extent in the direction of said first circumferential groove in said third portion of extent, following after said second portion of extent, with a v-shaped widened sectional contour in said radially outer surface and with a greater increase in its width than in said second portion of extent and said first portion of extent.

4. The tread profile of claim 1, wherein said transverse grooves are formed as extending in their first portion of extent with a direction of extent that forms an angle of inclination α with the circumferential direction U wherein 0°≤α≤20°.

5. The tread profile of claim 1, wherein said transverse grooves are formed as extending in their portion of extent between said vertex point and said first circumferential groove with a direction of extent that forms an angle of inclination β with the axial direction A, wherein 0°≤β≤35°.

6. The tread profile of claim 1, wherein said transverse grooves are formed along their extent in the direction of said first circumferential groove in said first portion of extent and said second portion of extent with a v-shaped widened sectional contour in said radially outer surface with a continuously increasing width.

7. The tread profile of claim 1, wherein: said first portion of extent and said second portion of extent define a transition; said transverse grooves each have a groove base; and, said groove base is formed with a step, with an abrupt change in the groove depth from T.sub.1max to T.sub.2 at said transition, wherein 0 mm≤(T.sub.2−T.sub.1max)≤3 mm.

8. The tread profile of claim 1, wherein: said transverse grooves include first transverse grooves which are formed with a constantly aligned circumferential orientation along their extent from said beginning of extent to said first circumferential groove and are formed in said circumferential rib.

9. The tread profile of claim 1, wherein: said transverse grooves include second transverse grooves which are formed with a circumferential orientation changing at said vertex point along their extent from said beginning of extent to said first circumferential groove and are formed in said circumferential rib.

10. The tread profile of claim 8, wherein: said transverse grooves include second transverse grooves which are formed with a circumferential orientation changing at said vertex point along their extent from said beginning of extent to said first circumferential groove and are formed in said circumferential rib.

11. The tread profile of claim 1, wherein the pneumatic vehicle tire is a pneumatic passenger car tire.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described with reference to the drawings wherein:

(2) FIG. 1 shows a circumferential portion of a tread profile of a passenger car tire in plan view;

(3) FIG. 2 shows an enlarged portion of a circumferential rib of the tread profile from FIG. 1 in plan view;

(4) FIG. 3 shows a sectional representation of a transverse groove of the circumferential rib from FIG. 2 according to section from FIG. 2;

(5) FIG. 4 shows the transverse groove from FIG. 3 in a sectional representation according to section IV-IV from FIG. 2;

(6) FIG. 5 shows the transverse groove from FIG. 3 in a sectional representation according to section V-V from FIG. 2;

(7) FIG. 6 shows an alternative formation of a transverse groove of the circumferential rib from FIG. 2 in a sectional representation according to section VI-VI from FIG. 2;

(8) FIG. 7 shows the transverse groove from FIG. 6 in a sectional representation according to section VII-VII from FIG. 2; and,

(9) FIG. 8 shows the transverse groove from FIG. 6 in a sectional representation according to section VIII-VII from FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

(10) FIG. 1 shows a tread profile of a pneumatic vehicle tire of a passenger car in which, in a conventional way, a number of radially raised profile bands which respectively extend over the entire circumference of the pneumatic vehicle tire and are aligned in the circumferential direction U are arranged next to one another in the axial direction A of the pneumatic vehicle tire. In this case, a profile band 31 or 32 is respectively arranged in each of the two tire shoulders and profile bands formed as circumferential ribs 1, 33 and 34 are arranged axially between the two tire shoulders. The two profile bands 31 and 32 are for example rows of profile blocks of a known kind, in the case of which profile block elements arranged one behind the other in the circumferential direction are respectively separated from one another in the circumferential direction U by transversely running transverse grooves. The circumferential ribs 1, 33 and 34 are circumferential ribs of a known kind, which extend over the entire circumference of the pneumatic vehicle tire and are aligned in the circumferential direction U. The circumferential rib 1 is axially separated from the row of profile blocks 31 in a known way by a circumferential groove 2 that is made to extend over the entire circumference of the pneumatic vehicle tire and is aligned in the circumferential direction U of the pneumatic vehicle tire. The circumferential rib 1 is separated axially from the circumferential rib 33 by a circumferential groove 3. The circumferential rib 33 is separated axially from the circumferential rib 34 by a circumferential groove 35. The circumferential rib 34 is separated axially from the row of profile blocks 32 by a circumferential groove 36 of a known kind. The ground contact width T.sub.A extends in the axial direction A from the region of axial extent of the row of shoulder profile blocks 31 formed in the left-hand shoulder into the axial region of extent of the row of profile blocks 32 formed in the right-hand shoulder.

(11) The rows of profile blocks 31 and 32 and also the circumferential ribs 1, 33 and 34 are bounded outwardly in the radial direction R of the pneumatic vehicle tire by a radially outer surface 9 forming the ground contact surface within the ground contact width T.sub.A. The circumferential grooves 2, 3, 35 and 36 are bounded inwardly in the radial direction R in a known way by a groove base which extends over the entire circumference of the pneumatic vehicle tire.

(12) Transverse grooves 4 are formed in the circumferential rib 1, spaced apart from one another in the circumferential direction U of the pneumatic vehicle tire and distributed over the circumference of the pneumatic vehicle tire. The transverse grooves 4 extend in this case in the axial direction A from a position measured at the distance K from the circumferential groove 3 in the radially outer surface 9 to the circumferential groove 2 and enter it.

(13) The circumferential grooves 2 and 3 are formed along their extent with a maximum profile depth P.sub.T, measured inwardly in the radial direction R.

(14) As represented in FIGS. 2 to 5, the transverse grooves 4 are bounded inwardly in the radial direction R by a groove base 10 and in the circumferential direction U on one side—represented in FIG. 2 above the groove base 10—by a groove wall 11 arranged after the groove base 10 in the circumferential direction U and in the circumferential direction U on the other side—represented in FIG. 2 under the groove base 10—by a groove wall 12 arranged before the groove base 10 in the circumferential direction U. The transverse groove 4 is bounded along its extent at the end of its extent pointing away from the circumferential groove 2 by a groove wall 13. Here, the groove walls 11, 12 and 13 extend in each case in the radial direction R from the groove base 10 of the groove 4 to the radially outer surface 9.

(15) As can be seen in FIG. 2, the transverse groove 4 is formed from the beginning of its extent, formed in the groove wall 13, with three portions of extent 5, 6 and 7, formed one behind the other, along its extent up to the circumferential groove 2. The groove 4 is in this case formed in its first portion of extent 5, which extends from the position of the beginning of extent in the groove wall 13 to a vertex point 8 in the course of the groove 4, in a straight line while forming an angle of inclination α with the circumferential direction U. Following after the vertex point 8, the transverse groove 4 is formed in a second portion of extent 6 in a straight line and in the extension thereof in a straight line is formed in a third portion of extent 7 as extending in a straight line. In the second portion of extent 6 and in the third portion of extent 7, the transverse groove 4 is formed as extending in the course of its extent while forming an angle of inclination β with the axial direction A of the pneumatic vehicle tire. The angle α is in this case formed with 0°≤α≤20° and the angle β is formed with 0°≤β≤35° as the angle chosen. For example, they are chosen as α=15° and β=30°.

(16) The transverse groove 4 is in this case formed with a constant orientation in the circumferential direction U from the groove wall 13 along its extent up to the circumferential groove 2.

(17) In the region of the vertex point 8, the angle formed between the course of the groove base 10 in the first portion of extent 5 and in the second portion of extent 6 over the groove wall 11 is less than 180°.

(18) The groove wall 11 forms at its intersection with the radially outer surface 9 an intersecting edge S.sub.1. The groove wall 12 forms at its intersection with the radially outer surface 9 an intersecting edge S.sub.2. In the region of the intersecting edge S.sub.1, the first portion of extent 5 extends over a length of extent L.sub.1, measured in the direction of extent of the transverse groove 4 in the first portion of extent 5, the second portion of extent extends over a length of extent L.sub.2, measured in the direction of extent of the transverse groove 4 in the second portion of extent 6, and the third portion of extent extends over a length of extent L.sub.3, measured in the direction of extent of the transverse groove 4 in the second portion of extent 6.

(19) Along the extent of the intersecting edge S.sub.1, the transverse groove 4 is formed with a width b.sub.1, perpendicular to the direction of extent of the transverse groove 4 in the first portion of extent 5 in the radially outer surface 9, that is formed as continuously widened along the extent of the transverse groove 4 in the first region of extent 5 to the vertex point 8, and is taken further in the continuation in the second portion of extent 6 from the vertex point 8 with a continuously widened width b.sub.2, measured perpendicularly to the direction of extent of the groove 4 in the second portion of extent 6. Consequently, the width b of the transverse groove 4 in the radially outer surface 9 increases continuously from the beginning of extent over its entire extent at the groove wall 13 in the first portion of extent 5 and second portion of extent 6. The intersecting edge S.sub.1 is respectively formed as extending in a straight line in the first portion of extent 5 and in the second portion of extent 6. Similarly, the intersecting edge S.sub.2 is formed as a straight line in the first portion of extent 5. The intersecting edge S.sub.2 is also formed as a straight line in the second portion of extent 6 and in the third portion of extent 7, wherein it extends in a straight line from the vertex point 8 up to the circumferential groove 2. The intersecting edge S.sub.1 extends from the vertex point 8 over the length of extent L.sub.2 in a straight line up to a distance a from the circumferential groove 2, measured in the axial direction A, where the third portion of extent 7 begins.

(20) In this case, the intersecting edge S.sub.1 is formed in a first part of the third portion of extent 7 with a length of extent L.sub.3a, measured in the direction of extent of the intersecting edge S.sub.1 of the second portion of extent 6, as running in a straight line away from the intersecting edge S.sub.2, while forming a vertex point, and following after that is redirected back again toward the intersecting edge S.sub.2 and formed as running in a straight line over the length of extent L.sub.3b up to the circumferential groove 2. In this case, the width b.sub.3, measured perpendicularly to the course of the intersecting edge S.sub.1 in the second portion of extent 6, is also formed in each case as continuously increased along the extent of the transverse groove 4 in the direction of the circumferential groove 2 respectively in the portion of extent of the length of extent L.sub.3a and in the portion of extent L.sub.3b up to the circumferential groove. The increase in the width b.sub.3 over the length of extent is in this case greater in the portion of the length of extent L.sub.3a than in the in the first portion of extent 5, the second portion of extent 6 and the region of extent of the length L.sub.3b adjoining the circumferential groove 2.

(21) The intersecting edges S.sub.1 and S.sub.2 form along the extent of the transverse groove 4 in the first portion of extent 5, in the second portion of extent 6 and in the two sub-portions of the lengths L.sub.3a and L.sub.3b of the third portion of extent 7 in each case a v-shaped widening sectional contour of the transverse groove 4 in the radially outer surface 9.

(22) As represented in FIG. 3 and FIG. 4, the transverse groove 4 is formed in its first portion of extent 5 with a depth T.sub.1, which starting from a minimum value of the depth T.sub.1min, which it assumes at the position of the groove wall 13, increases continuously over the entire extent of the transverse groove 4 in the first portion of extent 5 up to the vertex point 8 to a maximum depth T.sub.1max, which it reaches at the position of the vertex point 8. At the transition between the first portion of extent 5 and the second portion of extent 6 at the position of the vertex point 8, the groove base 10 is then lowered—as represented in FIG. 3—while forming a step 8 to a depth T.sub.2, wherein, following after the step 8—as represented in FIG. 3 and FIG. 5—the transverse groove 4 is formed over its entire second portion of extent 6 with the depth T.sub.2, where T.sub.2≥T.sub.1max. The step 8 is in this case dimensioned such that, for the difference ΔT=(T.sub.2−T.sub.1max), it applies that: 0 mm≤ΔT≤3 mm. For example, the difference is formed as ΔT=1 mm.

(23) At the transition between the second portion of extent 6 and the third portion of extent 7—as represented in FIG. 3—the groove base 10 is raised to a depth T.sub.3 and extends with this depth T.sub.3 up to the circumferential groove 2. The depth T.sub.3 is formed with T.sub.3>T.sub.2. In the portion of extent of the length L.sub.3a of the third portion of extent 7, the transition between the depth T.sub.2 of the second portion of extent 6 and the depth T.sub.3 is formed with the groove base 10 formed as a ramp 15.

(24) The value of the minimum depth T.sub.1min is formed with 0 mm≤T.sub.1min≤0.2 mm. The maximum value T.sub.1max is formed with 4 mm≤T.sub.1max≤P.sub.T. The profile depth P.sub.T is formed with 7 mm≤P.sub.T≤8 mm.

(25) The depth T.sub.2 is formed with 7 mm≤T.sub.2≤8 mm.

(26) The depth T.sub.3 is formed with 3 mm≤T.sub.3≤5 mm as the chosen depth.

(27) The width b.sub.1 in the first portion of extent 5 is formed at the transition between the groove wall 13 and the groove wall 11 with its measured minimum width b.sub.1min where b.sub.1min=1.5 mm and at the transition to the second portion of extent with its maximum width b.sub.1max where b.sub.1max=3 mm. The width b.sub.2 is formed with its maximum width b.sub.2max at the position of the groove wall 11 at the transition between the second portion of extent 6 and the third portion of extent 7 where b.sub.2max=4 mm. The width b.sub.3 of the first part of the third portion of extent 7 of the transverse groove 4 is formed at the transition between the first part of the third portion of extent 7, with the length of extent L.sub.3a, and the second part of the third portion of extent 7, with the length of extent L.sub.3b, with its maximum b.sub.3max=5 mm. The width b.sub.4, measured perpendicularly to the course of the extent of the second portion of extent 6, of the second part of the third portion of extent 7 of the transverse groove 4 is formed at the position of intersection between the groove wall 11 and the circumferential groove 4 with its maximum b.sub.4max=5.5 mm.

(28) The lengths of extent L.sub.1, L.sub.2, L.sub.3 and L.sub.4 are formed with 10 mm≤L.sub.1≤15 mm, 10 mm≤L.sub.2≤20 mm, L.sub.3=5 mm and L.sub.4=5 mm.

(29) The axial distance a is formed with 8 mm≤a≤10 mm as the chosen distance.

(30) FIGS. 2, 3, 4 and 5 also show a further embodiment in which there is formed along the second portion of extent 6 in the groove wall 12 at the transition of the groove wall 12 to the radially outer surface 9 a bevel 16, which is aligned in the sectional planes formed perpendicularly to the direction of extent of the transverse groove 4 in the second portion of extent 6 while forming an angle of inclination ε where ε=45° with the radial direction R. In the case of this embodiment, the intersecting edge S.sub.2 is the intersecting edge with the radially outer surface 9 that is formed by extending the groove wall 12 in its radial extent outwardly up to the radially outer surface 9 and the width b.sub.2 is the distance between this formed intersecting edge S.sub.2 and the intersecting edge S.sub.1.

(31) FIGS. 1 and 2 also show another embodiment, with transverse grooves 4′ that are formed in the circumferential rib 1 and are formed analogously to the formation of the transverse grooves 4 with the first portion of extent 5, second portion of extent 6 and third portion of extent 7 and their respective courses. The transverse grooves 4′ are bounded on both sides of their groove base 10 in each case by flanks 11′ and 12′ and at the beginning of their extent by a groove wall 13′. Unlike in the case of the transverse groove 4, however, the transverse groove 4′ has from the beginning of its extent at the groove wall 13′ up to the circumferential groove 2 along its axial extent in its first portion of extent 5 a course of which the alignment in the circumferential direction U is oriented opposite to the alignment in the circumferential direction in the second and third portions of extent 6 and 7. Consequently, in this formation there is also included at the vertex point 8 a change in orientation of the course with regard to its circumferential alignment. In the embodiment represented in FIG. 2 it can be seen well that in the first portion of extent 5 of the transverse groove 4′ up to the vertex point 8 the circumferential orientation in FIG. 5 is chosen as upward and in the second and third portions of extent 6 and 7 up to the circumferential groove 2 the circumferential orientation in FIG. 5 is chosen as downward. In this case—as can be seen in FIGS. 2, 6, 7 and 8—the transverse groove 4′ is also formed in this configuration in the first portion of extent 5 with a depth T.sub.1 increasing continuously up to the vertex point 8, then following after a step 14 in the second portion of extent 6 with a constant depth T.sub.2 and in the third portion of extent 7 along a ramp 15 with a groove base 10 raised up to a depth T.sub.3. It can similarly be seen that, also in the case of this formation, the width b of the groove 4′ is increased continuously from the groove wall 13′ along the entire axial extent of the transverse groove 4′.

(32) FIGS. 1 and 2 show a further embodiment, in which transverse grooves 4 and transverse grooves 4′ are arranged one behind the other in alternating sequence in the circumferential rib 1, distributed over the circumference. It can be seen in this case that the direction of extent of the transverse grooves 4 and 4′ in the portion of extent between the circumferential groove 2 and the vertex point 8 is respectively formed as running substantially parallel.

(33) It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE NUMERALS

Part of the Description

(34) 1 Circumferential rib 2 Circumferential groove 3 Circumferential groove 4 Transverse groove 5 First portion of extent 6 Second portion of extent 7 Third portion of extent 8 Vertex point 9 Radially outer surface 10 Groove base 11 Groove wall 12 Groove wall 13 Groove wall 14 Step 15 Ramp 16 Bevel 31 Profile band 32 Profile band 33 Circumferential rib 34 Circumferential rib 35 Circumferential groove 36 Circumferential groove