Tire with sidewall inserts

Abstract

The subject of the present invention is a tire (1) comprising at least one sidewall (3) intended to cooperate with a sidewall insert (9) through fastening means (6), the goal being to customize the design of said sidewall. According to the invention, the fastening means (6) comprising a recess (7) formed in the axially outer sidewall layer (30) comprises a protrusion (8) projecting relative to the bottom surface of the recess (71) and extending from the bottom surface of the recess (71) to the vicinity of the axially outer surface of the sidewall (31), said protrusion (8) being stepped in such a way that its first narrow portion (81) has a minimum width Lpmin and its second wide portion (82) has a maximum width Lpmax, the difference Lpmax-Lpmin being at least equal to 1 mm and at most equal to 4 mm.

Description

Technical Field

[0001] The present invention relates to a tire more specifically intended to be equipped on a lightweight four-wheeled vehicle (automobile, van) or a two-wheeled vehicle (motorcycle), and having at least one sidewall with a sidewall insert intended to individualize the design of the tire sidewall.

Background Art

[0002] An ongoing concern of vehicle manufacturers and users is to individualize the design of the tire sidewall using coloring means and / or additional elements referred to herein as inserts.

[0003] Known coloring means are, for example, white colored rubber compositions that are present on the sidewall of the tire and contrast with the black color of the adjacent rubber composition. However, this technical solution has a number of drawbacks. First of all, certain chemical components, such as protective components present in the rubber composition adjacent to the coloring means, can migrate towards the colored rubber composition and, over time, it may gradually lose its color. In addition to this, the deformation of the sidewall throughout the service life of the tire can cause cracks in the colored rubber composition and deteriorate its appearance. Furthermore, the mechanical means used to mount the tire on its rim can also deteriorate the colored rubber composition by rubbing against it. Finally, the manufacture of tires with parts of different colors is more complex from an industrial point of view.

[0004] Among known inserts, European Patent No. 2692542 describes a decorative ring intended to be mounted between the bead and the rim of a tire. However, mounting this ring is delicate for reasons of its positioning. In addition to this, the presence of the ring between the bead and the rim of the tire can modify the mechanical behavior of the tire and thus that of the vehicle. Finally, in order to install it correctly, this ring runs the risk of requiring an adaptation of the shape of the rim that is no longer compliant with the specifications of the rim profile for which the tire was designed.

[0005] U.S. Patent No. 3,128,815 describes another insert in the form of a tire lining element intended to be removably engaged with the sidewall. This lining element may be fixed to the sidewall by various means, such as engagement of its ends with the sidewall, or attachment of its ends by fastening means that are raised or recessed relative to the sidewall. Furthermore, the described lining element covers a significant portion of the sidewall, typically at least one-third of the sidewall's surface area, and is positioned more specifically in the radially inner segment of the sidewall between the axial outermost point of the sidewall and the rim flange. However, because this lining element is positioned in the high-flex zone of the tire, it is prone to deforming and separating from the sidewall while the tire is running.

[0006] Japanese Patent Publication No. 11-151918 also describes a removable collar insert intended to be fixed to the tire sidewall near the tread within the radially outer segment of the sidewall by a mounting means recessed to the surface of the sidewall. However, such a mounting means does not allow the insert to be easily mounted on the tire, because when the tire is mounted on its rim and inflated, the shape of the insert there may be insufficient compared to the shape of the recess of the mounting means, depending on the inflation pressure or the width of the rim. In addition, when the tire is running, the locking of the insert within the sidewall may be corrected, for example under strong transverse acceleration, with the risk of the insert being ejected. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] European Patent No. 2692542 [Patent Document 2] U.S. Patent No. 3128815 [Patent Document 3] Japanese Patent Application Publication No. 11-151918 [Overview of the project] [Problems that the invention aims to solve]

[0008] The objective set by the inventors is to propose a tire that can be equipped with at least one sidewall insert that improves mounting on the sidewall and attachment thereto. [Means for solving the problem]

[0009] This objective is achieved by a tire for a lightweight vehicle intended to be mounted on a rim and equipped with at least one sidewall insert, the tire having a nominal cross-section of height H, and - The crown is connected to each of the two beads, with two side walls each intended to contact the rim, - At least one sidewall having fastening means intended to interact with at least one sidewall insert, Equipped with, - The fastening means extends at least partially circumferentially in the circumferential direction of the tire, and the fastening means comprises a recess formed in the axial outer sidewall layer extending axially from the axial outer sidewall surface toward the inside of the sidewall, comprising at least one rubber material. - The recess is divided axially inward by the bottom surface of the recess and radially by the two recess walls. - The recess has a depth Pc which is the maximum distance measured perpendicularly between the axial outer side wall surface and the bottom surface of the recess, equal to at least 2 mm in any meridional plane containing the rotation axis of the tire, and a width Lc which is measured between the axial outer side wall surfaces of the two recess walls, equal to at most 15% of the nominal cross-sectional height H of the tire. - The fastening means includes a projection that rises from the bottom surface of the recess and extends from the bottom surface of the recess to the vicinity of the axially outer side wall surface, - The protrusion is configured in a stepped arrangement of a first narrow portion that extends axially outward from the bottom surface of a recess, having a minimum width equal to the minimum protrusion width Lpmin, such that the difference Lpmax-Lpmin is at least equal to 1 mm and at most equal to 4 mm in any meridional plane, and a second wide portion that extends axially outward from the first narrow portion, having a maximum width equal to the maximum protrusion width Lpmax.

[0010] The principle of the present invention is to have a fastening means for a side wall insert, the fastening means comprising a circumferential recess formed in the axially outer side wall layer and a protrusion formed in this recess.

[0011] The recesses may be continuous or discontinuous in the circumferential direction, meaning they may be formed in separate circumferential portions.

[0012] The axially outer sidewall layer, where the recess is formed, extends axially from the axially outer sidewall surface in contact with the atmosphere to the outermost axial reinforcing layer, which is most often made of fabric. More specifically, the axially outer sidewall layer is in axially inward contact with a rubber compound, usually called a coating compound, that covers the reinforcing material of the outermost axial reinforcing layer.

[0013] The recess allows the sidewall to be fixed in place by locking the edge of the sidewall insert between its walls. This contributes to keeping the sidewall insert, which is prone to being released when the tire is moving, in place.

[0014] The recess also allows the sidewall insert to engage with the thickness of the sidewall so as not to create a significant protrusion relative to the axially outer sidewall surface, and thus not to disturb the airflow in the vicinity of the sidewall within this zone. As a result, the aerodynamic drag of the tire does not increase. Accordingly, the rolling resistance of the tire and therefore fuel consumption do not increase either.

[0015] According to the present invention, the depth Pc of the recess is at least equal to 2 mm.

[0016] When the depth Pc is less than 2 mm, the fixing means does not guarantee a sufficient attachment of the sidewall insert that enables it to withstand the various mechanical stresses applied during its use throughout its service life in the tire.

[0017] Also according to the invention, the width Lc of the recess is equal to at most 15% of the nominal section height H of the tire.

[0018] The width Lc of the recess must remain limited because as it increases, the deflection of the sidewall insert zone increases more during use, which causes significant deformation and potential fatigue problems of the sidewall insert. The deformation in the recess increases with the width Lc of the recess, which can specifically be expressed as a percentage of the nominal section height H of the tire or as an absolute value. The nominal section height H is defined by the usual standards related to the tire, such as those of the "European Tyre and Rim Technical Organisation" or "ETRTO" standard.

[0019] The protrusion formed in the recess from the bottom of the recess is intended to contact the axial inner surface of the sidewall insert and, due to its specific shape, enables the sidewall insert to be fixed. The protrusion consists of, in any meridian plane, a first narrow portion that extends axially outward from the bottom of the recess and has a minimum width equal to the minimum protrusion width Lpmin, and a second wide portion that extends axially outward from the first narrow portion and has a maximum width equal to the maximum protrusion width Lpmax. Such a protrusion has, in essence, a mushroom shape, with its stem being the first narrow portion and its cap being the second wide portion. This protrusion configuration enables the sidewall insert to be substantially retained on the protrusion and ensures that it is held in place under the mechanical bending stress and centrifugal stress applied to the tire when the tire is in motion.

[0020] Advantageously, the depth Pc of the recess is equal to at most 3 mm.

[0021] More advantageously, the depth Pc of the recess is equal to at most 7 mm, preferably equal to at most 5 mm.

[0022] When the depth Pc is greater than 7 mm, the thickness of the layer of rubber material on the inner side in the axial direction of the bottom surface of the recess is not sufficient to ensure mechanical cutting between the side wall insert intended to be engaged with this recess and the outermost axial reinforcement layer. This results in stress concentration at the bottom surface of the recess where cracks are likely to occur and a reduction in the durability of the side walls. Furthermore, with regard to manufacturing, a recess with a limited depth ensures the presence of a layer of rubber material on the inner side in the axial direction of the bottom surface of the recess, despite the significant movement of the materials present in this zone during the stages for assembling and then finishing the tire. In other words, a recess depth that is not excessively high makes it possible to ensure manufacturing tolerances.

[0023] Using an axially outer side wall layer with a width W in the fixing means, the difference between the thickness W of the axially outer side wall layer and the depth Pc of the recess is equal to at least 1 mm, preferably equal to at least 2 mm.

[0024] The thickness W is measured between the axially outer side wall surface and the axially outer fibers of the reinforcement of the outermost axial reinforcement layer, and this thickness thus takes into account the actual axially outer side wall layer and the axially outer coating layer of the outermost axial reinforcement layer. The difference between the thickness W of the axially outer side wall layer and the depth Pc of the recess defines, that is to say, the thickness of the layer of rubber material provided between the bottom surface of the recess and the outermost axial reinforcement layer.

[0025] A thickness of 1 mm is the minimum thickness of the layer of rubber material that ensures mechanical cutting between the side wall insert intended to be engaged with the above-mentioned recess and the axially inner reinforcement of the reinforcement at the interface with the axially outer side wall layer. This minimum thickness consequently avoids stress concentration at the bottom surface of the recess where cracks are likely to occur and a reduction in the durability of the side walls.

[0026] Advantageously, the width Lc of the recess is equal to at most 10% of the nominal section height H of the tire.

[0027] Similarly advantageous, the width Lc of the recess is equal to a maximum of 20 mm, and preferably to a maximum of 12 mm.

[0028] Preferably, the recess is formed in the axial outer sidewall layer made of a single rubber material.

[0029] As a result, no recesses are formed in composite layers, which are composed of overlapping materials and are therefore potentially sensitive to mechanical strength issues at the interfaces between these materials.

[0030] Advantageously, the lines that exist in each meridional plane and pass through the two intersections of each concave wall with the axially outer sidewall form an angle with the radial direction equal to a maximum of 25°, preferably equal to a maximum of 15°.

[0031] When angle A is greater than 25°, the axially outer sidewall surface generally becomes excessively inclined radially in the zone of the fastening means close to the tire bead. As a result, the sidewall of the recess is unable to hold the sidewall insert and will deform under the action of centrifugal force.

[0032] Preferably, the projection has a height Hp that is at least 2 mm less than the depth Pc of the recess in any meridional plane.

[0033] A minimum height value Hp equal to 2 mm less than the recess depth Pc allows the sidewall insert to be positioned on the protrusion without protruding beyond or only slightly beyond the axially outer sidewall surface, while still having sufficient fixing height. This configuration ensures effective fixing of the sidewall insert while still protecting it from potential wear of the sidewall against the curb. Furthermore, the limited engagement of the sidewall insert within the thickness of the sidewall allows it to be considered a design feature.

[0034] Similarly, preferably, the projection has a height Hp equal to at least 2 mm greater than the depth Pc of the recess in any meridional plane.

[0035] A maximum height value Hp equal to 2 mm greater than the depth Pc of the recess allows the insert to avoid protruding from the axially outer sidewall surface. This configuration, in other words, allows for undisturbed airflow near the sidewall in this zone. As a result, the aerodynamic drag of the tire does not increase. Correspondingly, the rolling resistance of the tire and therefore fuel consumption do not increase either. Furthermore, the susceptibility of the sidewall to potential wear against curbs remains limited.

[0036] When the side wall is provided with a protective ridge having an edge corner on its axially outer side wall surface and near the radially outer edge of the bead, and the fastening means has a circumferential mean line, the circumferential mean line of the fastening means is favorably positioned at a radial distance d1 equal to at least 4 mm radially outward of the edge corner of the protective ridge in any meridional plane.

[0037] The protective ridge is positioned on the axially outer sidewall and near the radially outer edge of the bead. Positioning near the radially outer edge of the bead means that the radially innermost point of the protective ridge is located at a radial distance of at least 4 mm from the radially outer edge of the rim flange on which the tire is intended to be mounted. Furthermore, the edge corners of the protective ridge are the vertices of the substantially triangular cross-section of the protective ridge that are not positioned on the axially outer sidewall.

[0038] The function of the protective ridge is to protect the flange of the rim on which the tire is intended to be mounted; therefore, it is the part of the tire most susceptible to abrasion against external elements such as curbs and stones, and also the part most likely to come into contact with the ground when the tire is removed. Consequently, the sidewall insert and thus the corresponding fastening means must be far enough away from the protective ridge to avoid damage. Furthermore, fastening means that are close to the protective ridge should be made more visible.

[0039] Equally advantageous, the circumferential mean line of the fastening means is positioned in any meridional at a radial distance d2 equal to at least 10% of the nominal cross-sectional height H of the tire, radially inward from an axial straight line passing through the midpoint H / 2 of the nominal cross-sectional height of the tire.

[0040] For certain tires having a small nominal cross-sectional height H and therefore a small sidewall height, the protective ridge is located on the outermost axial portion of the tire. For other tires, the outermost axial point of the tire is positioned on an axial line passing through the midpoint H / 2 of the tire's nominal cross-sectional height. For these tires, in order to avoid deterioration of the sidewall insert, especially when the sidewall wears against a curb, the circumferential average line of the corresponding fastening means is radially advantageously positioned at a radial distance d2 equal to at least 10% of the tire's nominal cross-sectional height H, radially inward from the axial line passing through the midpoint H / 2 of the tire's nominal cross-sectional height. Typically, the radial distance d2 is equal to at least 2 mm, and preferably at least 8 mm.

[0041] The present invention also relates to a sidewall insert intended to be mounted on the sidewall of a tire.

[0042] The sidewall insert is intended to interact with the fastening means according to any of the embodiments described above by engaging with a recess of the fastening means and by being secured on a protrusion of the fastening means.

[0043] In the case of a fastening means having a projection with an external meridian profile, the sidewall insert preferably has an internal meridian profile parallel to the external meridian profile of the projection such that the internal meridian profile of the sidewall insert has a minimum insert width Limin at a minimum projection width Lpmin and a maximum insert width Limax at a maximum projection width Lpmax. In other words, the sidewall insert has a mushroom shape that constitutes a female portion to which the male mushroom shape of the projection connects, which makes it possible to ensure good fastening.

[0044] In the first modification of the preferred embodiment of the sidewall insert, the difference Lpmax-Limin between the maximum projection width Lpmax and the minimum insert width Limin is at least equal to 1.5 mm.

[0045] In a second modification of the preferred embodiment of the sidewall insert, the difference Lpmax-Limin between the maximum projection width Lpmax and the minimum insert width Limin is up to 2 * E is equal to the distance between a straight line passing through the cross-section of the minimum insert width Limin and the axially outer supporting surface of the insert that supports the protrusion.

[0046] Specifically, in order to enable effective fixation, i.e., sufficient locking of the side wall insert above the protrusion, the difference Lpmax-Limin between the maximum protrusion width Lpmax and the minimum insert width Limin is within the range of [1.5 mm; 2 * Preferably included in [E]. A value lower than the lower limit carries the risk of difficulty in mounting the insert on the protrusion. A value higher than the upper limit carries the risk of reduced effectiveness of the fixation.

[0047] This spacing determines the optimal locking range between the sidewall insert and the projection, both at the maximum cross-section corresponding to their respective maximum widths Lpmax and Limax, and at the minimum cross-section corresponding to their respective minimum widths Lpmin and Limin. At the maximum cross-section, the locking is determined by Lpmax-Limax. At the minimum cross-section, the locking is determined by Lpmin-Limin.

[0048] The sidewall insert has a circumferential average diameter D2 that is equal to the average diameter D1 of the circumferential average line of the fastening means at most before the sidewall insert is fixed to the tire. Under these conditions, the sidewall insert is fixed to the fastening means under prestress, which contributes to effectively holding the sidewall insert in place within the sidewall with a low risk of release when the tire is running.

[0049] In certain embodiments, the sidewall insert may have a variable width near the axially outer sidewall surface. This involves a fastening means with a variable width in the recess and therefore a fastening means that does not exhibit rotational symmetry with respect to the rotation axis of the tire.

[0050] In a preferred embodiment, the sidewall insert comprises at least one polymer material, such as a rubber material, silicone, or thermoplastic material, e.g., polyurethane.

[0051] The one or more materials from which the sidewall insert is made must be sufficiently deformable so as not to generate excessive stress at the interface between the sidewall insert and the fastening means that would otherwise induce cracks and fatigue fractures in the tire sidewall. Rubber materials, silicones, or polymer materials such as thermoplastics, e.g., polyurethane, are considered to satisfy this requirement, although this list is not exhaustive.

[0052] When a sidewall insert is made of a material having a tensile modulus M2 at 10% elongation and is intended to interact with a fastening means made of a rubber material having a tensile modulus M1 at 10% elongation, M2 is advantageously at least 0.4 * Equivalent to M1. The sidewall insert must be rigid enough to allow it to be mounted on the sidewall.

[0053] When the sidewall insert is made of a material having a tensile modulus M2 at 10% elongation and is intended to interact with a fastening means made of a rubber material having a tensile modulus M1 at 10% elongation, M2 is also advantageously up to 5 * Equivalent to M1. The sidewall insert should not be excessively stiff so as not to generate excessive stress on the tire sidewall that would damage it when subjected to bending stress, and to reduce the risk of the sidewall insert being ejected by centrifugal force while the tire is running.

[0054] The sidewall insert preferably has a different color scheme and / or texture from that of the sidewall with fastening means. Since the object of the present invention is to personalize the design of the tire sidewall, the sidewall insert preferably has a color scheme and / or texture that differentiates it from the sidewall.

[0055] Preferably, the colored sidewall inserts may have one or more different colors from the normally black sidewalls. Similarly, the sidewall inserts are monochromatic to simplify their manufacture.

[0056] In certain embodiment variations, to further differentiate the sidewalls, the sidewall inserts may be covered with a graphic or, for example, a velvet-type texture.

[0057] Finally, the present invention relates to an assembly made of a tire according to any one of the tire embodiments described above and at least one sidewall insert according to any one of the sidewall insert embodiments described above.

[0058] Features of the present invention are shown in schematic figures 1 to 5, which are not drawn to scale. [Brief explanation of the drawing]

[0059] [Figure 1] This figure shows a meridional half-section through the tire according to the present invention mounted on the rim. [Figure 2] This is a meridional cross-sectional view taken through the fixing means according to the present invention. [Figure 3] This figure shows a meridional half-section of the tire according to the present invention, which is mounted on the rim and equipped with a side wall insert. [Figure 4] This is a meridional cross-sectional view taken through the fastening means according to the present invention, combined with a side wall insert. [Modes for carrying out the invention]

[0060] Figure 1 is a meridional half-section through a tire 1 according to the present invention mounted on a rim 2. The tire 1 for a lightweight vehicle is mounted on a rim 2 and may include at least one sidewall insert 9 (not shown). The tire 1 has a nominal cross-section of height H in the sense of ETRTO (European Tire and Rim Technical Organization) standards and includes two sidewalls 3 that connect the crown 4 to two beads 5, each intended to contact the rim 2. The illustrated sidewalls 3 include fastening means 6 intended to interact with the sidewall insert 9 (not shown). The fastening means 6 extends circumferentially in the circumferential direction XX' of the tire and is formed in an axial outer sidewall layer 30 having at least one rubber material and includes a recess 7 extending axially inward from the axial outer sidewall surface 31 of the sidewall 3. According to the present invention, the fastening means 6 includes a projection 8 that rises from the bottom surface of the recess and extends from the bottom surface of the recess to the vicinity of the axially outer side wall surface 31, wherein the projection 8 is configured in a stepped arrangement of a first narrow portion that extends axially outward from the bottom surface of the recess and has a minimum width equal to the minimum projection width Lpmin (not referenced) in any meridional YZ, and a second wide portion that extends axially outward from the first narrow portion and has a maximum width equal to the maximum projection width Lpmax. In a particular embodiment shown in Figure 1, the side wall 3 includes a protective ridge 32 having an edge corner 321 on its axially outer side wall surface 31 near the radially outer side of the bead 5. The edge corner 321 of the protective ridge 32 is the vertex of a substantially triangular cross-section of the protective ridge that is not located on the axially outer side wall surface 31. In the case of a fastening means 6 having a circumferential mean line 61, the circumferential mean line 61 of the fastening means 6 is positioned in the meridional YZ plane at a radial distance d1 equal to at least 4 mm on the radially outer side of the edge corner 321 of the protective ridge 32. Furthermore, the circumferential mean line 61 of the fastening means 6 is positioned in the meridional YZ plane at a radial distance d2 equal to at least 10% of the nominal cross-sectional height H of the tire 1, on the radially inner side of the axial straight line D passing through the midpoint H / 2 of the nominal cross-sectional height of the tire 1.

[0061] Figure 2 is a meridional cross-sectional view through the fastening means 6 according to the present invention. This is a detail view of Figure 1. The fastening means 6 comprises a recess 7 and a projection 8. The recess 7 is axially divided inward by a recess bottom surface 71 and radially divided by two recess walls 72. The recess 7 has a depth Pc which is the maximum distance measured perpendicularly between the axial outer sidewall surface 31 and the recess bottom surface 71 in the meridional plane YZ containing the rotation axis YY' of the tire, and a width Lc which is measured between the two recess walls 72 in the axial outer sidewall surface 31. The depth Pc of the recess 7 is at least equal to 2 mm and at most equal to 7 mm. The width Lc of the recess 7 is at most equal to 15% and preferably at most equal to 10% of the nominal cross-sectional height H of the tire 1. When the axial outer sidewall layer 30 has a thickness W in the fastening means 6, the difference between the thickness W of the axial outer sidewall layer 30 and the depth Pc of the recess 7 is at least equal to 1 mm. Furthermore, a straight line T located in the meridional plane YZ, passing through two intersection points 721 and 722 of each concave wall 72 with the axially outer side wall surface 31, forms an angle A with the radial direction ZZ' that is at most equal to 25°. Finally, in any meridional plane YZ, the projection 8 is configured by a stepped arrangement of a first narrow portion 81 extending axially outward from the bottom surface 71 of the recess and having a minimum width equal to the minimum projection width Lpmin, and a second wide portion 82 extending axially outward from the first narrow portion 81 and having a maximum width equal to the maximum projection width Lpmax.

[0062] Figure 3 is a meridional cross-section view of the tire according to the present invention, mounted on a rim and equipped with a sidewall insert. This is the tire from Figure 1 combined with the sidewall insert 9.

[0063] Figure 4 is a meridional cross-sectional view through the fastening means according to the present invention shown in Figure 2, combined with a sidewall insert. This is a detail view of Figure 4. The fastening means 6, which has a projection, has an outer meridional profile P. The sidewall insert 9 has an inner meridional profile P' parallel to the outer meridional profile P of the projection 8. The inner meridional profile P' of the sidewall insert 9 has a minimum insert width Limin at the minimum projection width Lpmin and a maximum insert width Limax at the maximum projection width Lpmax. Furthermore, in a preferred modification shown, the difference Lpmax-Limin between the maximum projection width Lpmax and the minimum insert width Limin is equal to at least 1.5 mm and at most 2 * E is equal to the distance between the straight line G passing through the cross-section of the minimum insert width Limin and the axial outer supporting surface 91 of the insert 9 that supports the protrusion 8.

[0064] The inventors further examined this invention for a tire of size 245 / 45 R 18 100 W XL intended to inflate to a recommended pressure equal to 2.9 bar and bear a recommended load equal to 800 kg.

[0065] The characteristics of the embodiments tested by the inventors are shown in Table 1 below.

[0066] [Table 1]

[0067] The inventors have found that the sidewall insert equipped on the sidewall of a tire according to the present invention allows for easy installation and more effective mounting. [Explanation of Symbols]

[0068] 1 tire 2 rims 6 Fixing means 9 Sidewall inserts H tire nominal section height

Claims

1. intended to be mounted on a rim (2) and which may be equipped with at least one sidewall insert (9), and which has a nominal cross section of height H; two side walls (3) respectively connecting the crown (4) to two beads (5) each intended to come into contact with said rim (2); at least one side wall (3) provided with fastening means (6) intended to interact with at least one side wall insert (9); Equipped with the fastening means (6) extending circumferentially in the circumferential direction (XX') of the tire and comprising recesses (7) formed in the axially outer sidewall layer (30) comprising at least one rubber material and extending axially from the axially outer sidewall surface (31) towards the inside of the sidewall (3), The recess (7) is bounded axially inward by a recess bottom surface (71) and radially by two recess walls (72), said recess (7) having a depth Pc, which is the maximum distance measured perpendicularly between said axially outer side wall surface (31) and said recess bottom surface (71), equal to at least 2 mm in any meridian plane (YZ) containing the tire's rotation axis (YY'), and a width Lc, measured on said axially outer side wall surface (31) between said two recess walls (72), equal to at most 15% of said nominal section height H of the tire (1), A tire (1) for a light vehicle, comprising: The fixing means (6) includes a protrusion (8) that protrudes from the recess bottom surface (71) and extends from the recess bottom surface (71) to the vicinity of the axially outer side wall surface (31), The protrusion (8) is constituted by a stepped arrangement of a first narrow portion (81) extending axially outward from the recess bottom surface (71) and having a minimum width equal to the minimum protrusion width Lpmin, and a second wide portion (82) extending axially outward from the first narrow portion (81) and having a maximum width equal to the maximum protrusion width Lpmax, such that the difference Lpmax-Lpmin is at least equal to 1 mm and at most equal to 4 mm in any meridian plane (YZ). A tire (1) characterized in that

2. Tyre (1) according to claim 1, characterized in that the depth Pc of the recess (7) is at least equal to 3 mm.

3. Tyre (1) according to claim 1 or 2, characterized in that the depth Pc of the recess (7) is at most equal to 7 mm.

4. said axially outer sidewall layer (30) having a thickness W at said fastening means (6); the difference between the thickness W of the axially outer sidewall layer (30) and the depth Pc of the recess (7) is at least equal to 1 mm; Tyre (1) according to any one of claims 1 to 3.

5. Tyre (1) according to any one of claims 1 to 4, characterized in that the width Lc of the recess (7) is equal to at most 10% of the nominal section height H of the tyre (1).

6. Tyre (1) according to any one of claims 1 to 4, characterized in that the width Lc of the recess (7) is at most equal to 20 mm.

7. Tyre (1) according to any one of the preceding claims, characterized in that the recess (7) is formed in an axially outer sidewall layer (30) made of a single rubber material.

8. 8. Tyre (1) according to any one of claims 1 to 7, characterized in that a straight line (T) lying in any meridian plane (YZ) and passing through two intersection points (721, 722) of each recessed wall (72) respectively with said axially outer side wall surface (31) forms with the radial direction (ZZ') an angle (A) equal to at most 25°.

9. 9. Tyre (1) according to any one of claims 1 to 8, characterized in that the protrusions (8) have a height Hp, in any meridian plane (YZ), at least equal to 2 mm less than the depth Pc of the recesses (7).

10. the side wall (3) comprises, on its axially outer side wall surface (31) and in the radially outer vicinity of the bead (5), a protective ridge (32) having an edge corner (321), the fastening means (6) having a circumferential mean line (61); the circumferential mean line (61) of the fastening means (6) is positioned in any meridian plane (YZ) radially outside the edge corners (321) of the protective ridge (32) at a radial distance d1 equal to at least 4 mm; Tyre (1) according to any one of claims 1 to 9.

11. 11. Tyre (1) according to claim 10, characterized in that the circumferential mean line (61) of the fastening means (6) is positioned in any meridian plane (YZ) radially inside an axial straight line (D) passing through the midpoint H / 2 of the nominal section height of the tyre (1) at a radial distance d2 equal to at least 10% of the nominal section height H of the tyre (1).

12. A sidewall insert (9) intended to interact with the fastening means (6) of a tire (1) according to any one of claims 1 to 11 by engaging in said recesses (7) of said fastening means (6) and by clipping onto said protrusions (8) of said fastening means (6).

13. 13. The sidewall insert (9) according to claim 12, characterized in that the fastening means (6) comprises a protrusion (8) with an outer meridional profile (P), and the sidewall insert (9) has an inner meridional profile (P') parallel to the outer meridional profile (P) of the protrusion (8), so that the inner meridional profile (P') of the sidewall insert (9) has a minimum insert width Limin at the minimum protrusion width Lpmin and a maximum insert width Limax at the maximum protrusion width Lpmax.

14. Sidewall insert (9) according to claim 12 or 13, characterized in that the difference Lpmax-Limin between the maximum protrusion width Lpmax and the minimum insert width Limin is at least equal to 1.5 mm.

15. The difference Lpmax-Limin between the maximum protrusion width Lpmax and the minimum insert width Limin is at most 2 * 15. A sidewall insert (9) according to any one of claims 12 to 14, characterized in that it is equal to E, E being the distance between a straight line (G) passing through a cross section of the minimum insert width Limin and an axially outer bearing surface (91) of the insert (9) bearing against said protrusion (8).

16. 16. A sidewall insert (9) according to any one of claims 12 to 15, characterized in that before the sidewall insert is fastened to the tire (1), it has a circumferential mean line with a mean diameter D2 at most equal to the mean diameter D1 of the circumferential mean line of the fastening means (6).

17. Sidewall insert (9) according to any one of claims 12 to 16, characterized in that it comprises at least one polymer material.

18. made of a material having a tensile modulus M2 at 10% elongation and intended to interact with fastening means (6) made of a rubber material having a tensile modulus M1 at 10% elongation, M2 is at least 0.4 * is equal to M1, Sidewall insert (9) according to any one of claims 12 to 17.

19. made of a material having a tensile modulus M2 at 10% elongation and intended to interact with fastening means (6) made of a rubber material having a tensile modulus M1 at 10% elongation, M2 is a maximum of 5 * is equal to M1, Sidewall insert (9) according to any one of claims 12 to 18.

20. 20. Side wall insert (9) according to any one of claims 12 to 19, characterized in that it has a different colour and / or texture to that of the side wall (3) comprising the fastening means (6).

21. An assembly (10) consisting of a tire (1) according to any one of claims 1 to 11 and at least one sidewall insert (9) according to any one of claims 12 to 20.

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