COMMERCIAL VEHICLE TYRE

Abstract

A commercial vehicle tire intended for mounting on an E.T.R.T.O. Standards Manual standardized 15 drop-center rim (width codes 5.25 to 9.75) with two rim flanges (2) and with two rim sections (3), each with a bead seat surface (3a), wherein the commercial vehicle tire has two bead regions with bead cores (4) and in each case one bead toe (6) and one bead contour on the outside of the tire and one on the inside of the tire, which bead contours adjoin one another at the bead toe (6), wherein each bead contour on the outside of the tire has a first segment (S.sub.1), which is in contact with the rim flange (2) when the commercial vehicle tire is mounted on the rim (1), and an outer contour region, which is at least partially in contact with the bead seat surface (3a) when the commercial vehicle tire is mounted on the rim (1).

The outer contour region is made up of three adjoining segments (S.sub.2, S.sub.3, S.sub.4), specifically a second segment (S.sub.2) which adjoins the first segment (S.sub.1), which comes into contact with the rim flange (2), at an external angle (.sub.1) of 190 to 225, a third segment (S.sub.3) which adjoins this second segment at an external angle (.sub.2) of 165 to 175, and a fourth segment (S.sub.4) which adjoins this third segment at an external angle (.sub.3) of 200 to 210, wherein the total width (B) of the second, third and fourth segments (S.sub.2, S.sub.3, S.sub.4), projected onto a reference line (g.sub.2) running at an angle () of 15 in relation to the second segment (S.sub.2), is 20.0 mm to 45.0 mm and wherein the fourth segment (S.sub.4) has a width (b.sub.4) of 20% to 35% of the total width (B) in this projection.

Claims

1-10. (canceled)

11. A commercial vehicle tire comprising: two rim flanges and with two rim sections, each with a bead seat surface, wherein the commercial vehicle tire has two bead regions with bead cores and in each case one bead toe and one bead contour on the outside of the tire and one on the inside of the tire, which bead contours adjoin one another at the bead toe, wherein each bead contour on the outside of the tire has a first segment (S.sub.1), which is in contact with the rim flange when the commercial vehicle tire is mounted on the rim, and an outer contour region, which is in contact with the bead seat surface when the commercial vehicle tire is mounted on the rim; wherein the outer contour region is made up of three adjoining segments (S.sub.2, S.sub.3, S.sub.4), which include a second segment (S.sub.2) which adjoins the first segment (S.sub.1), which comes into contact with the rim flange (2), at an external angle (.sub.1) of 1900 to 225, a third segment (S.sub.3) which adjoins this second segment at an external angle (.sub.2) of 1650 to 175, and a fourth segment (S.sub.4) which adjoins this third segment at an external angle (.sub.3) of 2000 to 210; wherein a total width (B) of the second, third and fourth segments (S.sub.2, S.sub.3, S.sub.4), projected onto a reference line (g.sub.2) running at an angle () of 15 in relation to the second segment (S.sub.2), is 20.0 mm to 45.0 mm and wherein the fourth segment (S.sub.4) has a width (b.sub.4) of 20% to 35% of the total width (B) in this projection.

12. The tire of claim 11, wherein the second segment (S.sub.2) has a width (b.sub.2) of 40% to 60% of the total width (B).

13. The tire of claim 11, wherein the second, the third and the fourth segment (S.sub.2, S.sub.3, S.sub.4), as viewed over the circumference of the bead region, are truncated cone lateral surfaces or similar to truncated cone lateral surfaces.

14. The tire of claim 11, wherein the first segment (S.sub.1), as viewed over the circumference of the bead region, is either a truncated cone lateral surface or a cylinder lateral surface or similar to such lateral surfaces.

15. The tire of claim 11, wherein the bead contour on the inside of the tire has an end section (7) which, together with the fourth segment (S.sub.4), defines the bead toe (6) with a toe tip (6a), wherein the end section (7), at the toe tip (6a), forms an angle (), of 80 to 90, with the fourth segment (S.sub.4).

16. The tire of claim 11, wherein the end section (7) of the bead contour, on the inside of the tire, of the bead region extends substantially as far as the inner edge of the bead core (4).

17. The tire of claim 11, wherein the bead contour on the inside of the tire runs outside the end section (7) in such a way that the angles between the fourth segment (S.sub.4) and tangents to the bead contour on the inside of the tire become smaller as the distance from the fourth segment (S.sub.4) increases.

18. The tire of claim 11, wherein the fourth segment (S.sub.4), at the bead toe (6), has an end section (4a) which has a width (b.sub.5) of 2.0 mm to 4.0 mm and runs in a rounded manner in the direction of the tire axis, not shown, with a radius of 0.5 mm to 3.0 mm.

19. The tire of claim 11, wherein the individual segments (S.sub.1, S.sub.2, S.sub.3 and S.sub.4) adjoin one another via rounded transitions with a radius of, for example, 1.0 mm to 10.0 mm.

20. The tire of claim 11, wherein the bead cores (4) consist of rubberized steel wires.

21. The tire of claim 11, the tire mounted on an E.T.R.T.O. Standards Manual standardized 15 drop-center rim (width codes 5.25 to 18.00).

Description

[0016] Further features, advantages and details of the invention will now be described in more detail with reference to the schematic drawing, which illustrates an exemplary embodiment. In the drawing:

[0017] FIG. 1 shows a bead region of a commercial vehicle tire in axial section or cross section, and

[0018] FIG. 2 shows an associated sectional view of a section of a 15 drop-center rim.

[0019] FIG. 1 shows, in cross section, a bead region of a commercial vehicle tire, for example a tire for trucks or buses. Commercial vehicle tires with bead regions designed according to the invention are intended for mounting on 15 drop-center rims, designed in accordance with the European Tyre and Rim Technical Organisation Standards Manual, as amended, sections 15 Drop-Center Rims (width codes 5.25 to 18.00) with nominal diameters of 17.5 inches, 19.5 inches, 20.5 inches, 22.5 inches or 24.5 inches.

[0020] FIG. 2 shows a sectional view through an edge section of a rim 1, which is a 15 drop-center rim, as mentioned. Said figure shows, in cross section, a rim flange 2 with a seat surface 2a on the inside of the rim and a rim section 3 inclined at an angle of 15 in relation to the rim axis (rotation axis of the rim 1), not shown, and in the direction of the drop center with a bead seat surface 3a on the inside of the rim and also running at an angle of 15 in relation to the rotation axis, not shown, of the rim 1. The seat surface 2a on the rim flange 2 and the bead seat surface 3a intersect one another along a circle encircling the rim 1, which in the cross section shown is symbolized by a point P.sub.1. The diameter of this circle corresponds to the respective rim diameter. In FIG. 2, the angle is drawn between the bead seat surface 3a and a dashed reference line g.sub.1 running parallel to the rim axis, not shown, through the point P.sub.1.

[0021] FIG. 1 shows the bead region, as it is formed in a vulcanized commercial vehicle tire, before the commercial vehicle tire is mounted on the rim 1. The bead region shown in FIG. 1 contains a bead core 4, which is drawn schematically and is round in the example, made of rubberized steel wires and a carcass layer 5, which is also merely indicated, surrounding the bead core 4. Other components that usually reinforce the bead region, such as bead reinforcement layers, are not shown.

[0022] The bead contour, on the outside of the tire, of the bead region is divided into four flat, directly successive segments, which are designated S.sub.1, S.sub.2, S.sub.3 and S.sub.4, at least partially come into contact with the rim 1 when the commercial vehicle tire is mounted and are at least partially in contact in the mounted state. By way of the segment S.sub.1, the bead region is in contact with the seat surface 2a of the rim flange 2 in the mounted state. The segments S.sub.2 to S.sub.4 are those that are partially or completely in contact with the bead seat surface 3a of the rim 1 when the commercial vehicle tire is mounted and in the mounted state usually of the commercial vehicle tire. Each segment S.sub.1 to S.sub.4 is a straight line in the bead cross section, and an annularly encircling surface on the bead of the commercial vehicle tire. Here, the segments S.sub.2, S.sub.3 and S.sub.4 are truncated cone lateral surfaces, and the segment S.sub.1 is either a truncated cone lateral surface or a lateral surface of a circular cylinder.

[0023] A point P.sub.2 is drawn in FIG. 1, this point substantially coinciding with the point P.sub.1 of the rim 1 and being located on the intersection circle encircling the bead region of the tire between the segment S.sub.1 and the segment S.sub.2. At the intersection P.sub.2, the segment S.sub.1 forms an external angle .sub.1, of 190 to 225, with the segment S.sub.2. A reference line g.sub.2 which runs in the axial direction and at an internal angle of 15 in relation to the segment S.sub.2 and, in the example, passes through the point P.sub.2 is also drawn in FIG. 1. In particular, the reference line g.sub.2 can run parallel to the rotation axis of the tire. Along another intersection circle encircling the bead region of the tire, which intersection circle is identified in FIG. 1 by a point P.sub.3, the segment S.sub.3 adjoins the segment S.sub.2. The segments S.sub.2 and S.sub.3 form an obtuse external angle .sub.2 of 165 to 175 with one another. A point P.sub.4 lies on another intersection circle present at the transition of the segment S.sub.3 into the segment S.sub.4 and encircling the bead region of the tire. The segments S.sub.3 and S.sub.4 form an external angle .sub.3 of 200 to 210 with one another.

[0024] The first segment S.sub.1, which comes into contact with the seat surface 2a of the rim flange 2, extends from the reference line g.sub.2 determined at a right angle up to a height h which corresponds at least to the rim flange height, so that h is usually 13.00 mm.

[0025] On the reference line g.sub.2 projected in FIG. 1, the segments S.sub.2 to S.sub.4 run together or in total over a width B equal to 20.00 mm to 45.00 mm, depending on the tire dimension. The segment S.sub.2 has a width b.sub.2, the segment S.sub.3 has a width b.sub.3 and the segment S.sub.4 has a width b.sub.4. The width b.sub.2 of the segment S.sub.2 is 40% to 60%, in particular 45% to 55%, of the width B. The width b.sub.4 of the segment S.sub.4 is 20% to 35% of the width B, and the width b.sub.3 is adapted in accordance with the widths b.sub.2 and b.sub.4.

[0026] The bead region has, on the inside of the tire, a bead contour, on the inside of the tire, which runs in a rounded manner overall and has an end section 7 which, together with the segment S.sub.4, defines a bead toe 6 with a toe tip 6a. At the bead toe 6, the end section 7 of the bead contour on the inside of the tire (see drawn tangent) forms an internal angle , of 80 to 90, with the segment S.sub.4. The end section 7 of the bead contour, on the inside of the tire, of the bead region extends substantially as far as the lower or inner edge of the bead core 4. To the side of the bead core 4, the angle between tangents to the bead contour on the inside of the tire and the segment S.sub.4 decreases continuously, until this angle above the bead core 4 is of the order of magnitude of 35 to 45.

[0027] Adjoining the toe tip 6a, the segment S.sub.4 has an end section 4a which has a width b.sub.5 of 2.0 mm to 5.0 mm and runs in a rounded manner in the direction of the tire axis, not shown, with a radius of 0.5 mm to 3.0 mm. The toe tip 6a can additionally be chamfered at an angle.

[0028] The transitions between the individual segments S.sub.1, S.sub.2, S.sub.3 and S.sub.4 are drawn as fold lines, but can also be slightly rounded, and therefore provided, for example, with rounded transitions with a small radius of the order of magnitude of 1.0 mm to 10.0 mm.

LIST OF REFERENCE SIGNS

[0029] 1 Rim [0030] 2 Rim flange [0031] 2a Seat surface [0032] 3 Rim section [0033] 3a Bead seat surface [0034] 4 Bead core [0035] 5 Carcass layer [0036] 6 Bead toe [0037] 6a Toe tip [0038] 7 End section [0039] h Height [0040] g.sub.1, g.sub.2 Reference line [0041] B Width [0042] b.sub.1, b.sub.2, b.sub.3 Width [0043] P.sub.1, P.sub.2, P.sub.3, P.sub.4 Point [0044] S.sub.1, S.sub.2 Segment [0045] S.sub.3, S.sub.4 Segment [0046] , Angle [0047] .sub.1, .sub.2, .sub.3 External angle [0048] Internal angle