Pneumatic tyres with improved belt layer durability

Abstract

The present invention relates to pneumatic vehicle tyres having a carcass layer, a belt layer which is arranged on the outer side of the carcass layer, and a tread rubber which is arranged on the outer side in a tyre radial layer of the belt layer, wherein the belt layer comprises a pair of crossing belts which have a belt angle, as an absolute value, of not less than 10° and not more than 45° and a belt angle with opposite signs in each case, and a circumferential reinforcement layer which is formed by steel cords and has a belt angle within a range ± 5° in relation to the tyre circumferential direction. The pneumatic vehicle tyres additionally have, in the region of the edges of the circumferential reinforcement layer, shoulder strips formed from nylon or nylon hybrid materials comprising aramid or steel, and wherein the shoulder strips are formed from parallel strands or a woven fabric. The shoulder strips provide the tyre with improved durability of the belt plies, particularly in the edge region. The present invention furthermore relates to the use of such shoulder strips in such pneumatic tyres, and to vehicles equipped with such pneumatic tyres.

Description

[0001] Description

[0002] Pneumatic tires with improved belt layer durability

[0003] Description of the invention

[0004] The present invention relates to pneumatic vehicle tires comprising a carcass layer, a belt layer arranged on the outer side of the carcass layer, and a tread rubber arranged on the outer side in the tire radial direction of the belt layer, wherein the belt layer comprises a pair of cross belts having a belt angle, as an absolute value, of not less than 10° and not more than 45° and a belt angle each having opposite signs, and a circumferential reinforcing layer formed by steel cords having a belt angle within a range of ± 5° with respect to the tire circumferential direction.The pneumatic vehicle tires additionally have shoulder strips in the region of the edges of the circumferential reinforcement layer, which shoulder strips are formed from nylon or nylon hybrid materials with aramid or steel. The shoulder strips are formed from parallel strands arranged at an angle within a range of ± 5° with respect to the tire circumferential direction, or from a fabric. The present invention further relates to the use of such shoulder strips in such pneumatic tires, as well as to vehicles equipped with such pneumatic tires.

[0005] State of the art

[0006] A tire construction with a belt layer in which the cords are arranged at an angle of 0° to ± 5° relative to the tire equator (here, the intersection line of a plane orthogonal to the tire axis through the center of the tire tread), and in which this belt layer is arranged between two cross belts, provides improved durability for correspondingly equipped tires, while also reducing uneven wear across the tire tread. The concept of equipping tires with such belt layers in the belt layer is described, for example, in EP 2 191 983 B1.

[0007] A disadvantage of such a design, however, is that the "0°" belt layer cannot be designed with a width greater than the width of the cross belts between which the belt layer is mounted, as this significantly increases the susceptibility of the belt layer to cord or filament breakage, especially in the edge area. Such a larger width would, however, be advantageous in terms of the edge durability of the tire's belt layer and rolling resistance.

[0008] US 2010282392 A1 discloses a tire with fibers with a flattened cross-section embedded as a layer in the tire body. The fibers are interconnected and oriented with respect to the center plane through the tire so that they form an angle of 0 to 90°. The fibers can be arranged in a layer, in which fibers at the outer edge of the layer can be made of a flexible material such as aramid, while the fibers toward the center are made of steel.

[0009] US 2010252163 A1 discloses a motorcycle tire with a tire carcass over which a layer of strands oriented at an angle of 0 to 5° is arranged. The strands are formed from steel cords in the area close to the tire equator and from organic fibers toward the tire edge.

[0010] DE 10 2022 200359 A1 discloses a pneumatic tire with a maximum number of one belt, with reinforcements for the belt ply provided in the area of ​​the belt edges. These reinforcements can be made of various materials, including steel, nylon, and aramid.

[0011] Against this background, there is a need for a pneumatic tire design that can realize the benefits of improved edge retention of the tire's belt layer and improved rolling resistance without having to pay for this at the expense of increased susceptibility to cord and filament breakage in the "0°" belt layer. The present invention addresses this need.

[0012] Detailed description of the invention

[0013] In the investigations underlying this invention, it was surprisingly discovered that by modifying a pneumatic tire with a pair of cross belts and a circumferential reinforcement layer with additional reinforcements in the region of the tire edge, formed from parallel strands or cords or a woven fabric made of nylon or nylon hybrid materials with aramid or steel, improved edge durability and improved durability of the circumferential reinforcement layer can be achieved without simultaneously increasing the susceptibility to edge fractures in the circumferential reinforcement layer. Because they are at least partially formed from organic material, the reinforcements are lightweight, while at the same time, due to their survivability ("compression fatigue"), they are not subject to any relevant limitations in terms of durability compared to steel.

[0014] In a first aspect, the present invention accordingly relates to a pneumatic tire having a carcass layer, a belt layer arranged on the outer side of the carcass layer, and a tread rubber arranged on the outer side of the belt layer in the tire radial direction, wherein the belt layer comprises a pair of cross belts having a belt angle, as an absolute value, of not less than 10° and not more than 45° and a belt angle with opposite signs, respectively, and a circumferential reinforcing layer formed by steel cords having a belt angle within a range of ± 5° with respect to the tire circumferential direction, characterized in that shoulder stiffeners made of nylon or nylon hybrid materials with aramid or steel are formed in the region of the edges of the circumferential reinforcing layer, and wherein the shoulder stiffeners are formed of parallel arranged strands or a woven fabric.In other words, in the specified tires, the belt layer has at least three belts, namely two belts designed as cross belts (the belt cords of which cross when the belt layer is viewed from above) and one belt designed as a circumferential reinforcing layer.

[0015] In addition to these belts, the tire contains "shoulder strips," which are additional reinforcements located in the tire shoulder area. These are made partly or not at all from steel, but from the organic material nylon, and in which the material is in the form of parallel strands or a woven fabric. The shoulder strips are generally significantly narrower than the belt layers and are made of strands that are smaller than the strands or cords from which the belt layers themselves are made. Thus, the overall dimension (width, height) is smaller than that of the belt layers.

[0016] In the context of the invention described herein, the "edge" of the circumferential reinforcement layer refers to the points of the circumferential reinforcement layer that are the greatest distance from the tire equator. References to "edges" of other belt layers below also refer to the points in the respective layer that are the greatest distance from the tire equator.

[0017] In a preferred embodiment, the shoulder strips are formed from cords and in particular have a number of ends of the cords constituting the shoulder strips of 40 to 140 ends / 100 mm, preferably 80 to 110 ends / 100 mm and more preferably 85 to 100 ends / 100 mm (compared to a maximum number of ends in the belt layers of approximately 64 ends / 100 mm, although the number of ends is usually in the range of 38 to 50 ends / 100 mm).

[0018] As mentioned above, the cords forming the shoulder strips, or the fabric itself, are not made of steel, unlike the cords otherwise used in tires, but of nylon or nylon hybrid materials with aramid or steel. Nylon cords, for example, can be formed from a multitude of nylon filaments that are first twisted into individual strands, and then several of the strands (e.g., two or three strands) are twisted into cords. A nylon fabric, for example, is formed from nylon threads that, unlike cords, are aligned not only in the length direction but also in the width direction of the fabric, and the threads are bonded together to form a fabric.

[0019] In the context of the invention described herein and as normally understood by those skilled in the art, nylon refers to aliphatic polyamides, which are the condensation product of a mixture of diacids and diamides or of an organic compound containing an amine and a carboxylic acid function. Industrially important "nylon" polyamides include, for example, the polyamides known as PA6, PA 6.6, PA 6.10, PA 6.12, PA 11, or PA 12.

[0020] Nylon hybrid materials, as used here, are, in particular, cords and fabrics made from a mixture of nylon threads or strands and threads or strands of the material with which the nylon threads or strands are combined. It is also possible to use a mixture of nylon filaments and filaments of the material with which the nylon filaments are combined to produce "hybrid" threads or strands, and then produce a fabric from these hybrid threads or cords from the hydride strands.

[0021] The shoulder strips are usually made of the specified cords or fabric on the one hand, and of rubber material in which the cords or fabric are embedded or covered on the other.

[0022] The shoulder strips are preferably incorporated into the tire with a width in the range of 20 to 80 mm, and preferably 30 to 60 mm. The insertion can be carried out, for example, by spooling (or winding) rubberized strips with a width of approximately 10 mm onto the tire body to create one or more shoulder strip layers. The thickness of a shoulder strip layer is usually more than 0.6 mm, preferably more than 0.8 mm, and in a particularly preferred embodiment, is in the range of 0.65 to 1.1 mm.

[0023] For dimensioning the width of the strips in relation to the pneumatic tire in which the strips are incorporated, it is further advantageous if the width of the shoulder strips BS is matched to the width of the circumferential reinforcement layer BU in such a way that a ratio in the range of 0.07 < BS / BU < 0.5 results. Alternatively or additionally, it is preferred if the width of the shoulder strips BS is matched to the overall tire width SW in such a way that a ratio in the range of 0.05 < BS / SW < 0.25 results.

[0024] With regard to the position of the shoulder strips, it is preferred if they are arranged above the belts, i.e., closer to the tire surface, in the pneumatic tire. In other words, the shoulder strips in this case have a distance from the tire axis that is greater than the distance between all belt layers present in the tire. In particular, it is preferred if the shoulder strips are arranged in the tire circumferential direction above the cross belts and the circumferential reinforcement layer and below the tire tread, with the circumferential reinforcement layer preferably being arranged between the two cross belts.

[0025] Regarding the position of the shoulder strips, it is further preferred if they are arranged at a distance from the tread of 3 mm to 8 mm. If the shoulder strips are not arranged parallel to the tread, this distance indicates the position of the shoulder strips closest to the tread.

[0026] The shoulder strips may be arranged in the same position (i.e. distance from the tire equator and distance from the tread) on both shoulders with respect to the tire, or it is possible for the shoulder strips to be arranged in different positions.

[0027] If the pneumatic tire has main circumferential grooves, it is preferred that the shoulder strips are provided in a section in the tire that extends from the main circumferential groove Y closest to the tire edge X in the tire to the tire edge X. It is particularly preferred that the shoulder strip closest to the main circumferential groove in the section has a distance from the main circumferential groove Y of 3 to 20 mm, and preferably 5 to 15 mm.

[0028] A "main circumferential groove," in the context of the invention described herein, refers to a groove on the tire tread that extends over the entire circumference of the tire. A main circumferential groove is characterized by having a greater width and / or depth than other circumferential grooves present in the tire tread.

[0029] For the pneumatic tire according to the invention, it is furthermore expedient if the shoulder strips are applied in the cross-section of the tire such that the region filled by the shoulder strips (in the width direction of the tire) extends over the edges of the upper cross belt (i.e. oriented closer to the tire tread) and preferably over the edges of the upper and lower cross belts (i.e. oriented closer to the inside of the tire). In other words, the region filled by the shoulder strips begins closer to the tire equator than the edges of all belt plies present in the tire and extends further towards the tire edge than all edges of the belt plies. It is particularly preferred if the region filled by the shoulder strips extends at least 10 mm, more preferably at least 20 mm, and even more preferably 22 to 30 mm beyond the edge of the circumferential reinforcing layer in the direction of the tire equator.

[0030] The shoulder strips in the pneumatic tire according to the invention can be formed in a single layer or in multiple layers, e.g., two layers. "Multiple layers" here means that at least two shoulder strips are arranged one above the other such that the shoulder strips overlap at least over part of their surface. In a preferred embodiment, the shoulder strips are formed in two layers.

[0031] In a further preferred embodiment, the shoulder strips are formed in multiple layers, wherein the strips are formed in an I" arrangement (as shown in Figure 1, here the shoulder strips are formed from several narrower strips, wherein the strips are arranged in a Z shape so that part of one strip lies above the previous strip and the other part lies below the next strip). For this purpose, it is preferred if the strips from which the shoulder strips are formed have a width of 5 to 20 mm, and an overlap from one strip to the next strip results in a range of 30 to 70%. An overlap of 40 to 50% is preferred. For such an arrangement, it is irrelevant whether the upper strip parts (i.e. the parts positioned closer towards the tread) extend in the direction of the tire equator (as in Figure 1) or in the direction of the tire edge.

[0032] In general, an embodiment of the pneumatic tire according to the invention is further preferred in which the shoulder strips are arranged at an angle of 30 to 60° relative to the tread, and a plurality of shoulder strips are arranged offset from one another to form a reinforced portion.

[0033] In one embodiment, the shoulder strips are arranged in a region of the tire that extends partially parallel to the tire's contact surface on the road surface and protrudes into the tire's shoulder region (in this region, the tire no longer rests on the road surface). This achieves particularly favorable consolidation of the tire shoulder. In an alternative embodiment, the region in which the shoulder strips are arranged extends only in the area of ​​the pneumatic tire determined by the tire's contact surface on the road surface.

[0034] In the context of the invention specified here, the circumferential reinforcement layer is a layer with the above-specified cord orientation, in which the individual cords are arranged at substantially the same distance from one another. It is preferred that the distances from one cord to the next across the entire width of the layer do not deviate by more than 20%. Furthermore, for the circumferential reinforcement layer, the cords are aligned in one plane, and, for example, two cord plies cannot be aligned one above the other in the layer. The circumferential reinforcement layer is not subject to any relevant restrictions in the context of the invention specified here, and the layer is formed from steel cords according to the above specifications.However, it is preferred if the circumferential reinforcing layer has a number of ends of the belt cords constituting the circumferential reinforcing layer of 34 to 60 ends / 100 mm and more preferably 38 to 50 ends / 100 mm.

[0035] The width of the circumferential reinforcement layer is preferably matched to the width of the cross belts, or, if the two cross belts have a different width, to the width of the narrower cross belt, so that a ratio of width of the circumferential reinforcement layer / width of the narrower cross belt is established in the range of 0.7 to 0.9.

[0036] The width Ws of the circumferential reinforcing layer is preferably set so as to result in a ratio relative to the tread width TW within a range of 0.60 < Ws / TW < 0.90. In this way, on the one hand, by setting Ws / TW equal to or greater than 0.60, the ground contact pressure distribution is made uniform and the rolling resistance of the tire is reduced, and on the other hand, by setting Ws / TW less than or equal to 0.90, fatigue-induced breakage of the belt cords at the edge portions of the circumferential reinforcing layer is suppressed.

[0037] It is further preferable that the circumferential reinforcing layer is arranged on the inner side in the tire width direction from the left and right edges of a narrower cross belt of the pair of cross belts, and a width Wb of the narrower cross belt and a distance S from an edge of the circumferential reinforcing layer to an edge of the narrower cross belt are within such ranges that 0.03

[0038] ​The steel cords forming the circumferential reinforcement layer preferably have an elongation at break of less than 4.5%, and more preferably less than 4%. It is particularly preferred if the elongation at break is at least 1%, and in particular at least 2%. In one embodiment, the elongation at break is between 2 and 5%. In another embodiment, the elongation at break is more than 3% and less than 4.5%. Elongation at break refers here to the property of the cords as contained in the tire, and as can be determined, for example, by preparing the cords from the tire and subsequently measuring them. According to the invention, the elongation at break is to be determined by measurement in accordance with ASTM D 4975.

[0039] Another relevant property of the steel cords of the belt cords from which the circumferential reinforcing layer is configured is elongation. According to the invention, this elongation should preferably be no less than 1.0% and no more than 2.5% when the belt cords from which the circumferential reinforcing layer is configured are subjected to a tensile load of 100 N to 300 N. Such steel cords exhibit a good elongation rate when a light load is applied compared to ordinary steel wire, so they are resistant to the loads applied to the circumferential reinforcing layer during the period from tire manufacture to use. In this way, damage to the circumferential reinforcing layer can be suppressed for a long service life.

[0040] From the above, it follows that the cords of the circumferential reinforcement layer are preferably formed from a uniform material, i.e. steel with essentially the same mechanical properties (small deviations of ± 10% can be tolerated; preferably, the mechanical properties have less than 5% deviations across the entire cords in the circumferential reinforcement layer). The circumferential reinforcement layer can be produced by winding the cords from which the circumferential reinforcement layer is formed. It is expedient if, for this purpose, 1 to 3 cords are "wound" (i.e. positioned with the aid of a winding head) simultaneously onto a belt layer positioned beneath the circumferential reinforcement layer to be produced. It is very particularly preferred if one or two winding heads are used to form the circumferential reinforcement layer.

[0041] Another belt ply that can be included in the pneumatic tire according to the invention is a belt ply that has a large belt angle relative to the other belt plies included in the pneumatic tire (i.e., a belt angle that is greater than the belt angles of the other belt plies included in the pneumatic tire). This belt ply preferably has a belt angle of not less than 45° and not more than 70°. Furthermore, it is preferred for such a belt ply to be laminated on the outer side of the carcass layer in the tire radial direction (i.e., this belt ply forms the first belt ply following the carcass layer). The circumferential reinforcement layer is then applied over this belt ply, either directly or with one or more intermediate belt plies.

[0042] The pneumatic tires according to the invention preferably have an aspect ratio (= ratio of the tire height to the tire width in %) of 80% or less, wherein in certain cases an aspect ratio of 70% or less may be specified as preferred, an aspect ratio of 60% or less as more preferred, and an aspect ratio of 55% or less as even more preferred.

[0043] It is understood that the belt layers and the shoulder strips in the tire are embedded in a rubber matrix, wherein the layers are surrounded by rubber that forms the body of the tire. In addition to the tread, larger areas or "cushions" in which only rubber material is present are formed in the shoulder area of ​​the tire. In a further aspect, the present invention relates to the use of shoulder stiffeners in the region of the edges of the circumferential reinforcement layer of a pneumatic tire, which shoulder stiffeners are formed from nylon or nylon hybrid materials with aramid or steel, to increase edge durability and / or to improve rolling resistance and / or to improve the durability of the circumferential reinforcement layer, wherein the circumferential reinforcement layer has a belt angle within a range of ± 5° with respect to the circumferential direction of the circumferential reinforcement layer.

[0044] In yet another aspect, the present invention relates to a vehicle, and in particular a lorry or bus, equipped with at least one pneumatic tire as described above.

[0045] 1, an example of a tire structure according to the invention is shown based on a tire cross-section: FIG. 1 shows a pneumatic tire 10 according to the invention with a carcass layer 11, a first belt layer 12 (with a large belt angle), two cross belts 13 and 15 and a circumferential reinforcement layer 14 positioned between these belts. A main circumferential groove Y is positioned above the belt layers 12 to 15. In the region of the edges of the belt layers 12 to 15, two layers of shoulder stiffeners 16 are arranged in the tire body in an arrangement in which a part. The region in which the shoulder stiffeners are arranged is at a distance from the main circumferential groove Y and the tire edge X.The width of the shoulder stiffener modified area 16A is determined by the number of layers of strips used and the distance between the strips; the area is arranged at a distance 16B from the main circumferential groove furthest from the tire equator.

[0046] Figure 2 shows the different belt layers in plan view.

[0047] Figure 3 shows two different possibilities for arranging the shoulder stiffeners in a tire with two cross-belt plies 13 and 15 and a circumferential reinforcement layer 14. In both configurations, the shoulder strips are formed from several smaller strips arranged side by side to form the shoulder strip 16A. In the first configuration, a shoulder strip ply is formed from several adjacent strips, and a further, similarly constructed second ply is arranged offset over the first ply so that gaps in the first ply are covered by stiffeners of the second ply. If the strips are applied with opposite feed rates, the gap between two strips in the same layer is not completely covered.In the first configuration, the strip furthest from the belt layers is arranged parallel to the belt layers, and additional strips are placed to cover part of the underlying strip. This way, the strips are arranged at an angle to the belt layers.

[0048] Figure 4 shows a schematic cross-section through a tire with a carcass layer 11 and four belt layers (12 to 15) analogous to the figures described above. Figure 4A also shows the structure of the tire sidewall 22 with the tire bead core 18, the flipper 17, an apex 1 and 2 (19, 21), the ripstrim 20, as well as shoulder pads 23 and belt tread 24 of the tire. Figure 4A shows the tire without the inventive development with side strips. In Figure 4B, two layers of side strips 16 are attached above the belt pad above the last belt layer 15.

[0049] With regard to the above disclosure, it should be noted that embodiments described as preferred or expedient for one aspect are also considered preferred or expedient for other aspects, provided that the combination of features does not result in obvious contradictions. Likewise, even if this is not explicitly described for reasons of brevity, all combinations of embodiments of the aspects are considered combinable and as encompassed and described in their combination by the disclosure, unless it is explicitly stated that combinability does not exist or this is clear from the context. The present invention and the effects achieved thereby are illustrated in more detail below using a few exemplary embodiments; however, these should not be construed as limiting the scope of protection of the application in any way.

[0050] Examples

[0051] Example 1 :

[0052] Test tires of size 385 / 55 R22.5 with the structure shown in Figure 4 and a sequence of carcass ply, belt ply with a belt angle of 70° and a width of 290 mm, a belt ply with a belt angle of 18° and a width of 310 mm (= 1st cross belt), a belt ply with a belt angle of 0° and a width of 240 mm, and a belt ply with a belt angle of -18° and a width of 290 mm (= 2nd cross belt) were simulated using specially developed software. The belt plies had the following number of cords in each layer: 1st cross belt: 38 EPDM (= "ends per decimeter"), 0° belt ply: 40 EPDM; 2nd cross belt: 38 EPDM. The tires were simulated either without shoulder stripes or with shoulder stripes with a width of 55 mm (in two layers on top of each other), a distance of the inner end to the side shoulder of 10 mm and a distance between the 0° belt and lower shoulder strip of 7 mm.

[0053] The simulations were based on nylon and a hybrid material made of nylon and aramid. Rolling resistance, belt durability, bead durability, and abrasion were determined for each tire. The results are presented in Table 1 below. A tire with the same construction but without shoulder strips was simulated as a reference (Ref.).

[0054] Table 1 : Values ​​greater than 100 indicate an improvement over the reference value, while values ​​less than 100 indicate a deterioration (not observed in this case). The abrasion is evaluated against a reference value, with the percentage indicating the improvement (in terms of reduced abrasion) in percent.

[0055] As shown in Table 1, the tire with shoulder stiffeners made of hybrid material exhibits the best values ​​for the properties tested. Particularly strong improvements are observed in belt durability. A significant improvement is also observed compared to nylon as a reference material.

[0056] List of reference symbols

[0057] 10 pneumatic tires

[0058] 11 Carcass layer

[0059] 12 belt layer (large belt angle)

[0060] 13 first cruciate belt

[0061] 14 Circumferential reinforcement layer

[0062] 15 second cruciate belt

[0063] 16 shoulder stripes

[0064] 16A area filled with shoulder stripes

[0065] 16B Distance to the main circumferential groove

[0066] 17 Protective layer

[0067] 18 pinball machines

[0068] 19 Tire bead core

[0069] 20 Apex

[0070] 21 Rimstrip

[0071] 22 Apex 2

[0072] 23 Side wall

[0073] 24 shoulder pads

[0074] 25 belt pads

[0075] X Tire edge

[0076] Y main circumferential groove

Claims

Patent claims 1. A pneumatic tire comprising a carcass layer, a belt layer arranged on the outer side of the carcass layer, and a tread rubber arranged on the outer side of the belt layer in the tire radial direction. The belt layer comprises a pair of cross belts having a belt angle, as an absolute value, of not less than 10° and not more than 45° and each having a belt angle with opposite signs, and a circumferential reinforcing layer formed by steel cords having a belt angle within a range of ± 5° with respect to the tire circumferential direction.or a tissue., 2. A pneumatic tire according to claim 1, wherein the shoulder strips have a number of ends of the cords constituting the shoulder strips of 40 to 140 ends / 100 mm and preferably 80 to 110 ends / 100 mm.

3. A pneumatic tire according to claim 1 or 2, wherein the shoulder strips are arranged in the tire circumferential direction above the cross belts and the circumferential reinforcing layer and below the tire tread, wherein preferably the circumferential reinforcing layer is arranged between the two cross belts.

4. Pneumatic tire according to at least one of claims 1 to 3, wherein the shoulder strips have a width BS such that a ratio of BS to the width of the circumferential reinforcing layer BU results in the range of 0.07 < BS / BU < 0.

5.

5. Pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips have a width BS such that a ratio of BS to the total tire width SW results in the range of 0.05 < BS / SW < 0.

25.

6. A pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips are provided in a portion in the tire extending from the main circumferential groove Y closest to the tire edge X in the tire to the tire edge X, the shoulder strip closest to the main circumferential groove having a distance from the main circumferential groove Y of the tire of 3 to 20 mm, and preferably 5 to 15 mm.

7. Pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips are multi-layered and preferably two-layered.

8. Pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips are formed in a Z~l~ arrangement, wherein an overlap from one strip to the next strip is preferably in the range of 30 to 70% and more preferably of 40 to 50%.

9. A pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips have a distance from the tire axis which is greater than the distance between all belt layers present in the tire.

10. A pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips are arranged in the cross-section of the tire such that the area filled by shoulder strips extends over all edges of belt plies contained in the tire, and preferably extends at least 10 mm, preferably at least 20 mm and more preferably 22 to 30 mm beyond the edge of the circumferential reinforcing layer in the direction of the tire equator.

11. Pneumatic tire according to at least one of the preceding claims, wherein the shoulder strips are arranged at a distance from the tread of 3 mm to 8 mm.

12. A pneumatic tire according to at least one of the preceding claims, wherein the circumferential reinforcing layer has a number of ends of the belt cords constituting the circumferential reinforcing layer of 34 to 60 ends / 100 mm, and preferably 38 to 50 ends / 100 mm.

13. A pneumatic tire according to at least one of the preceding claims, wherein the steel cords forming the circumferential reinforcing layer have an elongation at break of less than 4.5%, preferably less than 4.0%, and more preferably in the range of 1 to 3%.

14. A pneumatic tire according to at least one of the preceding claims, wherein the steel cords for forming the circumferential reinforcing layer are produced by simultaneously winding 1 to 3 cords, preferably using one or two winding heads.

15. A pneumatic tire according to at least one of the preceding claims, wherein the pneumatic tire further comprises a belt having a belt angle, as an absolute value, of not less than 45° and not more than 70°, which is preferably laminated on the outer side in the tire radial direction of the carcass layer.

16. A pneumatic tire according to at least one of the preceding claims, which has an aspect ratio of 80% or less, preferably 70% or less and more preferably 60% or less.

17. Use of shoulder stiffeners in the area of ​​the edges of the circumferential reinforcing layer of a pneumatic tire, which are made of nylon or nylon hybrid materials with aramid or steel, to increase the edge durability and / or to improve the rolling resistance and / or to improve the durability of the Circumferential reinforcement layer, wherein the circumferential reinforcement layer has a belt angle within a range of ± 5° with respect to the circumferential direction of the circumferential reinforcement layer.

18. Vehicle, in particular in the form of a truck or Bus equipped with at least one pneumatic tire according to one of claims 1 to 16.

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