Tire comprising a sidewall insert

Abstract

The subject of the present invention is a tyre (1) comprising at least one sidewall (3) intended to cooperate with a sidewall insert (9) by means of anchoring means (6), and which aims to customize the design of said sidewall. According to the invention, the anchoring means (6) comprising a recess (7) formed in the axially outer sidewall layer (30) comprise a protrusion (8) which is raised with respect to the recess bottom (71) and which extends from the recess bottom (71) to the vicinity of the axially outer face of the sidewall (31), said protrusion (8) being stepped so that a first narrow portion (81) has a minimum width Lpmin, a 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, and more specifically, to a tire intended for use on a light four-wheeled vehicle (motor vehicle, van) or a two-wheeled vehicle (motorcycle) and comprising at least one sidewall having a sidewall insert designed to personalize the design of the tire sidewall. Background Technology

[0002] Vehicle manufacturers and users continue to focus on personalizing tire sidewall designs using color devices and / or additional elements (referred to as inserts in this application).

[0003] Known coloring devices are colored rubber compositions, such as white compositions, present in the tire sidewall and contrasting with the black of adjacent rubber compositions. However, this approach has several drawbacks. First, certain chemical components (e.g., protective components) present in the adjacent colored rubber compositions may migrate to the colored rubber composition, causing it to gradually lose its color over time. Additionally, sidewall deformation throughout the tire's lifespan can cause cracking to begin at the colored rubber composition, deteriorating its appearance. Furthermore, the machinery used to mount the tire to its rim can also cause the colored rubber composition to deteriorate due to friction against the machinery. Finally, from an industrial perspective, manufacturing tires that include different colored portions is more complex.

[0004] Among known inserts, document EP 2692542B1 describes a decorative ring intended for installation between the tire bead and the rim. However, the installation of this ring is tricky due to its location. Furthermore, the presence of the ring between the tire bead and the rim can alter the tire's mechanical properties, and consequently, the vehicle's mechanical properties. Finally, to install the ring correctly, there is a risk that the rim geometry needs to be adapted, meaning the rim geometry will no longer conform to the standard rim profile for which the tire was designed.

[0005] Document US 3128815 describes another type of insert designed to be detachably engaged with the tire sidewall in the form of a tire cover element. This cover element can be secured to the sidewall by various means, such as its ends engaging within the sidewall, or by anchoring devices that bulge or recess relative to the sidewall. Moreover, the cover element covers a significant portion of the sidewall, typically at least one-third of the sidewall surface area, and is more specifically arranged in the radially inner section of the sidewall between the outermost axial point of the sidewall and the rim flange. However, because this cover element is located in a highly deflective area of ​​the tire, it is prone to deformation and detachment from the sidewall as the tire travels.

[0006] Document JPH11151918 also describes a removable colored insert designed to be secured to the tire sidewall in the radially outer segment near the tread via an attachment device recessed relative to the sidewall surface. However, because the geometry of the insert may be insufficient compared to the geometry of the attachment device recess (depending on the inflation pressure or the rim width), this attachment device may make it difficult to install the insert onto the tire when it is mounted on its rim and inflated. Furthermore, the locking of the insert in the sidewall may change as the tire travels, for example, under large lateral accelerations, posing a risk of the insert being ejected. Summary of the Invention

[0007] The inventors aim to provide a tire that is equipped with at least one sidewall insert that improves the mounting and attachment of the sidewall.

[0008] This objective has been achieved by tires for light vehicles, designed to be mounted on rims and capable of being equipped with at least one sidewall insert, having a nominal cross-section of height H and comprising:

[0009] - The tire crown is attached to the two sides of the two tire beads, each tire bead designed to contact the rim.

[0010] - At least one sidewall including an anchoring device designed to interact with at least one sidewall insert.

[0011] - An anchoring device that extends at least partially circumferentially along the circumferential direction of the tire and includes a recess formed in the axial outer tire sidewall layer, the axial outer tire sidewall layer comprising at least one rubber material and extending axially from the axial outer tire sidewall toward the inner sidewall.

[0012] - A recess, which is defined axially by the inwardly extending bottom of the recess and radially by two recess walls.

[0013] The recess has a depth Pc in any meridional plane including the tire's axis of rotation, the maximum distance measured perpendicularly between the axial tire sidewall and the bottom of the recess, and a width Lc between the two recess walls measured at the axial tire sidewall, wherein the depth Pc is at least equal to 2 mm and the width Lc is at most equal to 15% of the tire's nominal section height H.

[0014] - The anchoring device includes a protrusion that protrudes relative to the bottom of the recess and extends from the bottom of the recess to near the axial tire sidewall.

[0015] - The protrusion is composed of a first narrow portion and a second wide portion arranged in a stepped manner in any meridian plane. The first narrow portion extends axially from the bottom of the recess outward and has a minimum width equal to the minimum protrusion width Lpmin. The second wide portion extends axially from the first narrow portion outward and has 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.

[0016] The principle of the present invention is to have an anchoring device for a sidewall insert, the anchoring device comprising a circumferential recess formed in the axially outer sidewall layer and a protrusion formed in the recess.

[0017] The recess can be circumferentially continuous or circumferentially discontinuous, that is, it is composed of multiple independent circumferential parts.

[0018] The axial tire sidewall, with recesses formed therein, extends axially from the axial tire sidewall (which is in contact with atmospheric air) to the outermost axial reinforcement layer (which is composed of a reinforcement, most commonly fabric). More specifically, the axial tire sidewall is in axial inward contact with a rubber compound (commonly referred to as a rubber-coated compound) that coats the reinforcement of the outermost axial reinforcement layer.

[0019] The recess anchors the tire sidewall by locking the edge of the sidewall insert between the walls of the recess. This helps keep the sidewall insert in place as the tire travels, and the sidewall insert can be easily ejected.

[0020] This recess also allows the sidewall insert to engage within the thickness of the sidewall, thus preventing a significant protrusion relative to the axially outer sidewall and consequently minimizing disturbance to airflow near the sidewall in this area. Therefore, it does not increase tire aerodynamic drag. Correspondingly, it also does not increase tire rolling resistance or, consequently, fuel consumption.

[0021] According to the present invention, the depth Pc of the recess is at least 2 mm.

[0022] If the depth Pc is less than 2 mm, the anchoring device cannot ensure sufficient attachment of the sidewall insert throughout its service life, which is capable of withstanding the various mechanical stresses applied to the tire during tire use.

[0023] Also according to the present invention, the width Lc of the recess is at most equal to 15% of the nominal section height H of the tire.

[0024] The width Lc of the recess must be limited because the greater the width Lc, the greater the deflection in the sidewall insert area during use, which can cause significant deformation of the sidewall insert and potential fatigue problems. The deformation at the recess specifically increases with the width Lc, and can be expressed as a percentage of the tire's nominal section height H or as an absolute value. The nominal section height H is defined by common tire-related standards, such as the European Tire and Rim Technology Organization (ETRTO) or other similar standards.

[0025] The protrusion formed from the bottom of the recess is designed to contact the axially inner surface of the sidewall insert and to anchor the sidewall insert through its specific shape. The protrusion is thus composed of a first narrow portion and a second wide portion arranged in a stepped manner in any meridional plane. The first narrow portion extends axially outward from the bottom of the recess and has a minimum width equal to the minimum protrusion width Lpmin, while the second wide portion extends axially outward from the first narrow portion and has a maximum width equal to the maximum protrusion width Lpmax. Such a protrusion therefore has a roughly mushroom-like shape, with the stem of the mushroom forming the first narrow portion and the cap forming the second wide portion. This protrusion configuration allows the sidewall insert to be effectively clamped onto the protrusion and ensures that the sidewall insert remains in place under the mechanical bending and centrifugal stresses applied to the tire as it travels.

[0026] Advantageously, the depth Pc of the recess is at most 3 mm.

[0027] More advantageously, the depth Pc of the recess is at most 7 mm, and preferably at most 5 mm.

[0028] If the depth Pc is greater than 7 mm, the thickness of the rubber material layer located axially inside the bottom of the recess is insufficient to ensure mechanical isolation between the sidewall insert and the outermost axial reinforcement layer, which are designed to engage within the recess. This leads to stress concentration at the bottom of the recess, making it prone to cracking and reducing sidewall durability. Furthermore, for manufacturing, the limited depth of the recess ensures the presence of a thick rubber material layer axially inside the bottom of the recess during tire manufacturing and subsequent finishing steps, without considering significant material displacement in this area. In other words, a moderate recess depth ensures manufacturing tolerances.

[0029] Given that the axial tire sidewall has a thickness W at the anchoring device, the difference between the thickness W of the axial tire sidewall and the depth Pc of the recess is at least equal to 1 mm, preferably at least equal to 2 mm.

[0030] Thickness W is measured between the axial outer tire sidewall and the axial outermost reinforcement fiber: this thickness therefore takes into account the actual axial outer tire sidewall and the axial outermost reinforcement coating. The difference between the thickness W of the axial outer tire sidewall and the depth Pc of the recess thus defines the thickness of the rubber material layer included between the bottom of the recess and the axial outermost reinforcement.

[0031] A thickness of 1 mm is the minimum thickness of the rubber material layer, which ensures mechanical isolation between the sidewall insert designed to engage in the recess and the axially inner reinforcement located at the junction with the outer sidewall layer. This minimum thickness thus avoids stress concentration at the bottom of the recess, which is prone to cracking, and reduces sidewall durability.

[0032] Advantageously, the width Lc of the recess is at most equal to 10% of the nominal section height H of the tire.

[0033] Also advantageously, the width Lc of the recess is at most 20 mm, and preferably at most 12 mm.

[0034] Preferably, the recess is formed in the axial outer sidewall layer made of a single rubber material.

[0035] Accordingly, the recess is not formed in the composite layer, which is composed of a stack of materials and is therefore potentially sensitive to mechanical strength issues at the interfaces between the materials.

[0036] Advantageously, the straight line existing in any meridian plane and passing through the two intersection points of each concave wall and the axial tire sidewall respectively forms an angle of at most 25° with the radial direction, preferably at most 15°.

[0037] When angle A is greater than 25°, the axial tire sidewall becomes excessively inclined relative to the radial direction in the area of ​​the anchoring device that is generally close to the tire bead. Therefore, the sidewall of the recess cannot hold the sidewall insert, and the sidewall insert will deform under the action of centrifugal force.

[0038] Preferably, the protrusion has a height Hp in any meridian plane, the height Hp being at least equal to the depth Pc of the recess minus 2mm.

[0039] A minimum height value Hp, equal to the depth Pc of the recess minus 2 mm, allows the sidewall insert to be positioned on the protrusion with sufficient anchoring height while not protruding beyond, or only very slightly protruding beyond, the axial sidewall. This configuration thus ensures effective anchoring of the sidewall insert while protecting it from scratches that may occur from rubbing against curbs. Furthermore, the restricted engagement of the sidewall insert within the sidewall thickness ensures that it can be considered a design feature.

[0040] Preferably, the protrusion has a height Hp in any meridian plane, the height Hp being at most equal to the depth Pc of the recess plus 2mm.

[0041] The maximum height value Hp, equal to the depth Pc of the recess plus 2mm, prevents the insert from protruding relative to the axial outer tire sidewall. This configuration therefore does not disrupt airflow near the tire sidewall in this area. Consequently, it does not increase the tire's aerodynamic drag. Correspondingly, it does not increase the tire's rolling resistance or, consequently, fuel consumption. Furthermore, sensitivity to scratches that may occur when the tire sidewall rubs against curbs remains limited.

[0042] For a sidewall with a protective ridge having corners and an anchoring device having a circumferential mean line on the axial outer sidewall of the tire sidewall and near the radial outer side of the bead, the circumferential mean line of the anchoring device is advantageously arranged radially in any meridional plane at a radial distance d1 at least equal to 4 mm outside the corners of the protective ridge.

[0043] The protective ridge is positioned on the axial outer sidewall of the tire and near the radial outer edge of the bead. "Positioned near the radial outer edge of the bead" means that the innermost radial point of the protective ridge is radially positioned at least 4 mm from the outer edge of the rim flange on which the tire is intended to be mounted. Furthermore, the corners of the protective ridge are the vertices of the basic triangular cross-section of the protective ridge, which are not located on the axial outer sidewall of the tire.

[0044] Since the function of the sidewall ridge is to protect the flange of the rim on which the tire is mounted, it is the part of the tire most susceptible to scratches from external factors such as curbs and stones, and the part most likely to come into contact with the ground when the tire is removed. Therefore, the sidewall inserts and thus the corresponding anchoring devices must be sufficiently far away from the sidewall ridge to avoid damage. Furthermore, anchoring devices located close to the sidewall ridge make them more visible.

[0045] Furthermore, the circumferential mean line of the anchoring device is arranged radially inside the axial line in any meridional plane at a radial distance d2 at least equal to 10% of the nominal section height H of the tire, the axial line passing through the midpoint H / 2 of the nominal section height of the tire.

[0046] If, for some tires with a small nominal section height H and thus a small sidewall height, the protective ridge is the outermost part of the tire's axial direction, then for other tires, the outermost point of the tire's axial direction is located on an axial straight line passing through the midpoint H / 2 of the tire's nominal section height. For these tires, to avoid damage to the sidewall inserts, particularly when the sidewall scrapes against curbs, the circumferential mean line of the corresponding anchoring device is advantageously arranged radially inside the axial straight line at a radial distance d2 at least equal to 10% of the tire's nominal section height H, which passes through the midpoint H / 2 of the tire's nominal section height. Typically, the radial distance d2 is at least 2 mm and preferably at least 8 mm.

[0047] The present invention also relates to a sidewall insert intended for mounting on the sidewall of a tire.

[0048] The sidewall insert is designed to interact with the anchoring device according to any of the above embodiments by engaging in the recess of the anchoring device and clamping onto the protrusion of the anchoring device.

[0049] Given that the anchoring device includes a protrusion with an outer meridian profile, the sidewall insert preferably has an inner meridian profile parallel to the outer meridian profile of the protrusion, such that the inner meridian profile of the sidewall insert has a minimum insert width Limin at the minimum protrusion width Lpmin and a maximum insert width Limax at the maximum protrusion width Lpmax. In other words, the sidewall insert has a mushroom shape, which constitutes the interlocking concave portions of the convex mushroom shape of the protrusion, ensuring good anchoring.

[0050] According to a first variant of the preferred embodiment of the sidewall insert, the difference between the maximum protrusion width Lpmax and the minimum insert width Limin, Lpmax-Limin, is at least equal to 1.5 mm.

[0051] According to a second variant of the preferred embodiment of the sidewall insert, the difference between the maximum protrusion width Lpmax and the minimum insert width Limin, Lpmax-Limin, is at most equal to 2*E, where E is the distance between the straight line passing through the section of the minimum insert width Limin and the axial outer support surface of the insert abutting against the protrusion.

[0052] Specifically, for effective anchoring—that is, for the sidewall insert to be fully locked onto the protrusion—the difference between the maximum protrusion width Lpmax and the minimum insert width Limin, Lpmax-Limin, is preferably within the range of [1.5 mm; 2*E]. Below this lower limit, there is a risk that the insert will be difficult to install onto the protrusion. Above this upper limit, there is a risk of poor anchoring performance.

[0053] This range defines the optimal locking range between the sidewall insert and the protrusion 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, locking is defined by Lpmax-Limax. At the minimum cross-section, locking is defined by Lpmin-Limin.

[0054] The circumferential average line of the sidewall insert, having an average diameter D2, is at most equal to the average diameter D1 of the circumferential average line of the anchoring device before the sidewall insert is anchored to the tire. Under these conditions, the sidewall insert is anchored in the anchoring device under prestress, which helps to effectively keep the sidewall insert in place in the sidewall with a low risk of popping out as the tire travels.

[0055] According to a specific implementation, the sidewall insert may have a variable width near the axially outer tire sidewall. This includes the variable width of the recessed portion of the anchoring device, and thus the anchoring device does not exhibit rotational symmetry about the tire's axis of rotation.

[0056] According to a preferred embodiment, the sidewall insert comprises at least one polymer material such as rubber, silicone, or thermoplastic material such as polyurethane.

[0057] One or more materials used in the fabrication of the sidewall insert must be sufficiently deformable to prevent excessive stress at the junction between the sidewall insert and the anchoring device, which could lead to tire sidewall cracking and fatigue fracture. Polymer materials such as rubber, silicone, or thermoplastic materials like polyurethane (this list is not exhaustive) would meet this requirement.

[0058] Given that the sidewall insert is made of a material having a tensile modulus of elasticity M2 at 10% elongation, and is intended to interact with an anchoring device made of a rubber material having a tensile modulus of elasticity M1 at 10% elongation, M2 is advantageously at least equal to 0.4*M1. The sidewall insert must be sufficiently rigid to allow it to be mounted on the sidewall.

[0059] Given that the sidewall insert is made of a material having a tensile modulus of elasticity M2 at 10% elongation, and is designed to interact with an anchoring device made of a rubber material having a tensile modulus of elasticity M1 at 10% elongation, M2 is advantageously at most equal to 5*M1. The sidewall insert must not be too rigid to avoid generating excessive stress in the tire sidewall that could easily damage it when subjected to bending stress, and to reduce the risk of the sidewall insert being ejected due to centrifugal force during tire travel.

[0060] Preferably, the sidewall insert has a different color and / or texture than the sidewall including the anchoring device. Since the purpose of this invention is to personalize the design of the tire sidewall, the sidewall insert preferably has a color and / or texture that is distinct from the sidewall.

[0061] Preferably, the colored sidewall insert can have one or more colors that distinguish it from the usual black of the sidewall. It is also preferred that the sidewall insert be monochrome, in order to simplify its manufacture.

[0062] Depending on the specific implementation, the sidewall insert may be covered with a graphic or textured material, such as velvet, to further distinguish the sidewall.

[0063] Finally, the present invention relates to an assembly comprising a tire according to any of the tire embodiments described above and at least one sidewall insert according to any of the sidewall insert embodiments described above. Attached Figure Description

[0064] Through non-scale and schematic drawing Figures 1 to 4 To illustrate the features of the present invention:

[0065] - Figure 1 A radial half-section view of the tire according to the invention mounted on its rim.

[0066] - Figure 2 Meridian cross-sectional view through the anchoring device according to the invention.

[0067] - Figure 3 A radial half-section view of a tire according to the invention, mounted on its rim and equipped with a sidewall insert.

[0068] - Figure 4 Meridional cross-sectional view through the anchoring device according to the invention, which incorporates the sidewall insert. Detailed Implementation

[0069] Figure 1A radial half-section view of a tire 1 according to the invention mounted on its rim 2. The tire 1, for light vehicles, is mounted on the rim 2 and can be equipped with at least one sidewall insert 9 (not shown). The tire 1 has a nominal section of height H within the definition of ETRTO (European Tire and Rim Technology Organization) standards. The tire 1 includes two sidewalls 3 that respectively connect a crown 4 to two bead 5, each bead 5 intended to contact the rim 2. The sidewall 3 shown includes an anchoring device 6 intended to interact with the sidewall insert 9 (not shown). The anchoring device 6 extends circumferentially in the tire's circumferential direction XX' and includes a recess 7 formed in an axially outer sidewall layer 30 comprising at least one rubber material and extending axially from the axially outer sidewall 31 toward the inside of the sidewall 3. According to the invention, the anchoring device 6 includes a protrusion 8 that protrudes relative to the bottom of the recess and extends from the bottom of the recess to near the axial outer tire sidewall 31. The protrusion is formed in any meridian plane YZ by a stepped first narrow portion and a second wide portion. The first narrow portion extends axially outward from the bottom of the recess and has a minimum width equal to the minimum protrusion width Lpmin (not shown). The second wide portion extends axially outward from the first narrow portion and has a maximum width equal to the maximum protrusion width Lpmax. Figure 1 In the specific embodiment shown, the sidewall 3 includes a protective ridge 32 with corners 321 on the axial outer sidewall 31 and near the radial outer edge of the bead 5. The corners 321 of the protective ridge 32 are the vertices of the basic triangular cross section of the protective ridge, which are not located on the axial outer sidewall 31. The anchoring device 6 has a circumferential mean line 61, which is radially arranged in the meridional plane YZ at a radial distance d1 at least equal to 4 mm outside the corners 321 of the protective ridge 32. Moreover, the circumferential mean line 61 of the anchoring device 6 is radially arranged in the meridional plane YZ at a radial distance d2 at least equal to 10% of the nominal section height H of the tire 1 inside the axial line D, which passes through the midpoint H / 2 of the nominal section height of the tire 1.

[0070] Figure 2 This is a cross-sectional view along the meridian passing through the anchoring device 6 according to the invention. It is... Figure 1Detailed diagram. The anchoring device 6 includes a recess 7 and a protrusion 8. The recess 7 is axially defined by a recess bottom 71 extending inward and radially defined by two recess walls 72. The recess 7 has a depth Pc in the meridional plane YZ including the axis of rotation YY' of the tire, the maximum distance measured vertically between the axial tire sidewall 31 and the recess bottom 71, and a width Lc between the two recess walls 72 measured at the axial tire sidewall 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% of the nominal section height H of the tire 1, preferably at most equal to 10% of the nominal section height H of the tire 1. Given that the axial tire sidewall 30 has a thickness W at the anchoring device 6, the difference between the thickness W of the axial tire sidewall 30 and the depth Pc of the recess 7 is at least equal to 1 mm. Furthermore, the straight line T existing in the meridional plane YZ and passing through the two intersection points 721 and 722 of each recess wall 72 and intersecting the axial tire sidewall 31 forms an angle A with the radial direction ZZ' of at most 25°. Finally, the protrusion 8 in any meridional plane YZ is composed of a first narrow portion 81 and a second wide portion 82 arranged in a stepped manner. The first narrow portion 81 extends axially from the bottom 71 of the recess outward and has a minimum width equal to the minimum protrusion width Lpmin. The second wide portion 82 extends axially from the first narrow portion 81 outward and has a maximum width equal to the maximum protrusion width Lpmax.

[0071] Figure 3 A radial half-section view of a tire according to the invention, mounted on its rim and equipped with a sidewall insert. It will... Figure 1 The tire is combined with the sidewall insert 9.

[0072] Figure 4 For passing through the assembly with sidewall insert 9, Figure 2 The diagram shows a meridional cross-sectional view of the anchoring device 6 according to the present invention. It is... Figure 4 Detailed view. The anchoring device 6, including the protrusion 8, has an outer meridian profile P. The inner meridian profile P' of the sidewall insert 9 is parallel to the outer meridian profile P of the protrusion 8. The inner meridian 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. Furthermore, according to the preferred variant shown, the difference Lpmax-Limin between the maximum protrusion width Lpmax and the minimum insert width Limin is at least equal to 1.5 mm and at most equal to 2*E, where E is the distance between the straight line G passing through the section of the minimum insert width Limin and the axial outer support surface 91 of the insert 9 abutting against the protrusion 8.

[0073] The inventors have conducted more specific tests on the invention with a tire of size 245 / 45R 18 100W XL, which is designed to be inflated to a recommended pressure of 2.9 bar and to carry a recommended load of 800 kg.

[0074] The features of the examples tested by the inventors are presented in Table 1 below:

[0075] [Table 1]

[0076]

[0077]

[0078] The inventors noted that by equipping the tire sidewall with a sidewall insert according to the invention, the sidewall insert can be conveniently installed and attached more effectively.

Claims

1. An assembly (10) consisting of a tire (1) for light vehicle and of a sidewall insert (9): wherein said tire (1) having a nominal section height H and comprising two sidewalls (3) connecting a crown (4) to two beads (5) respectively, each bead (5) being intended to be in contact with a rim (2) on which the tire is intended to be mounted, at least one of said two sidewalls (3) comprising: - an axially outer sidewall face (31) in contact with atmospheric air, - an axially outer sidewall layer (30) extending radially from the crown (4) to the corresponding bead (5) and axially inwardly from the axially outer sidewall face (31), and comprising at least one rubber material, and - an anchoring device (6) interacting with the sidewall insert (9) and extending circumferentially along a circumferential direction (XX') of the tire, said anchoring device (6) comprising: - a recess (7) formed in the axially outer sidewall layer (30), said recess (7) being recessed from a portion of the axially outer sidewall face (31) extending radially on both sides of the recess, said recess (7) being axially inwardly delimited by a recess bottom (71) and radially by two recess walls (72), each extending from the recess bottom (71) to said portion of the axially outer sidewall face (31), and - a protrusion (8) protruding with respect to the recess bottom (71) and extending from the recess bottom (71) to an axially outer protrusion face of the protrusion, said axially outer protrusion face being located in the vicinity of said portion of the axially outer sidewall face (31), said recess (7) having in any meridian plane (YZ) comprising an axis of rotation (YY') of the tire: - a depth Pc measured perpendicularly between said portion of the axially outer sidewall face (31) and the recess bottom (71), and being at least equal to 2 mm, and - a width Lc measured between the two recess walls (72) at said portion of the axially outer sidewall face (31), and being at most equal to 15% of the nominal section height H of the tire (1), said protrusion (8) comprising in any meridian plane (YZ): - a narrow portion (81) extending axially outwardly from the recess bottom (71) and having a minimum width equal to a minimum width Lpmin of the protrusion (8), and - a wide portion (82) extending axially outwardly from the narrow portion (81) and having a maximum width equal to a maximum width Lpmax of the protrusion (8), said wide portion carrying the axially outer protrusion face and being stepped with respect to the narrow portion, the difference between the maximum width Lpmax and the minimum width Lpmin being at least equal to 1 mm and at most equal to 4 mm, said sidewall insert (9) being a single piece simultaneously engaged in said recess (7) and clamped on said protrusion (8), said single piece of the sidewall insert (9) comprising: - a front wall comprising an axially outer insertion face and an axially inner insertion face in contact with the axially outer protrusion face, and - two rear members, each protruding from the axially inner insertion face integral with the front wall, and each comprising two protrusions facing each other and directly receiving the narrow portion of the protrusion (8) therebetween to clamp the single piece on the protrusion (8), and two edges facing away from each other and locked between the two recess walls (72) to hold the single piece in place, said recess (7) being shaped in the thickness of said axially outer sidewall layer (30) and the single piece of said sidewall insert (9) being engaged in said thickness of said axially outer sidewall layer (30) so that the axially outer insertion face of the front wall of said sidewall insert (9) is radially flush with said portion of said axially outer sidewall face (31) on both sides of the recess (7).

2. The assembly (10) according to claim 1, wherein The depth Pc of said recess (7) is at least equal to 3 mm.

3. The assembly (10) according to any one of claims 1 and 2, wherein, The depth Pc of said recess (7) is at most equal to 7 mm.

4. Assembly (10) according to any one of claims 1 and 2, The axially outer sidewall layer (30) has a width W at the anchoring means (6), wherein 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.

5. The assembly (10) according to any one of claims 1 and 2, wherein, The width Lc of said recess (7) is at most equal to 10% of the nominal cross- sectional height H of the tyre.

6. The assembly (10) according to any one of claims 1 and 2, wherein, The width Lc of said recess (7) is at most equal to 20 mm.

7. The assembly (10) according to any one of claims 1 and 2, wherein, Said recess (7) is formed in the axially outer sidewall layer (30) made of a single rubber material.

8. The assembly (10) according to any one of claims 1 and 2, wherein, A straight line (T) present in any meridian plane (YZ) and passing through each of the two intersection points (721, 722) of each recess wall (72) with the axially outer sidewall face (31) respectively forms an angle (A) with the radial direction (ZZ’) of at most equal to 25°.

9. The assembly (10) according to any one of claims 1 and 2, wherein, Said protrusion (8) has a height Hp in any meridian plane (YZ) which is at least equal to the depth Pc of the recess (7) minus 2 mm.

10. The assembly (10) according to any one of claims 1 and 2, wherein, Said protrusion (8) has a height Hp in any meridian plane (YZ) which is at most equal to the depth Pc of the recess (7) plus 2 mm.

11. The assembly (10) according to any one of claims 1 and 2, wherein, At least one of said two sidewalls (3) further comprises a protective ridge (32) protruding from said axially outer sidewall face (31) and located in the vicinity of the radially outer portion of the respective bead (5).

12. The assembly (10) according to claim 11, wherein Said anchoring device (6) has a circumferential mean line (61) radially arranged, in any meridian plane (YZ), outside the corner (321) of the protective ridge (32) by a radial distance dl of at least equal to 4 mm.

13. The assembly (10) according to claim 12, wherein The circumferential mean line (61) of the anchoring device (6) is radially arranged, in any meridian plane (YZ), inside an axially straight line (D) passing through the middle point H / 2 of the nominal cross-sectional height of the tyre (1) by a radial distance d2 of at least equal to 10% of the nominal cross-sectional height H of the tyre (1).

14. The assembly (10) of claim 1, wherein the protrusion having a mushroom shape, the stem of the mushroom being formed by the narrow portion and the cap of the mushroom being formed by the wide portion.

15. The assembly (10) according to claim 1, wherein, The protrusion (8) has an outer meridian profile (P), the sidewall insert (9) has an inner meridian profile (P’) parallel to the outer meridian profile (P) of the protrusion (8), and the inner meridian profile (P’) of the sidewall insert (9) has a minimum width Limin at the minimum width Lpmin of the protrusion and a maximum width Limax at the maximum width Lpmax of the protrusion.

16. The assembly (10) according to claim 15, wherein The difference between the maximum width Lpmax of the protrusion (8) and the minimum width Limin of the sidewall insert (9) is at least equal to 1.5 mm.

17. The assembly (10) according to claim 15, wherein The difference between the maximum width Lpmax of the protrusion (8) and the minimum width Limin of the sidewall insert (9) is at most equal to 2*E, E being the distance between a straight line (G) passing through a section having the minimum width Limin of the sidewall insert (9) and an axially inner insertion face of the front wall of the insert (9).

18. The assembly (10) according to claim 1, wherein The single piece of the sidewall insert (9) has a circumferential mean line of average diameter D2 which is at most equal to the average diameter D1 of the circumferential mean line of the anchoring means (6) before anchoring of the sidewall insert to the tyre (1).

19. The assembly (10) according to claim 1, wherein The single piece of the sidewall insert (9) comprises at least one polymeric material.

20. Assembly (10) according to claim 1, wherein The single piece of the sidewall insert (9) is made of a material having a tensile elastic modulus M2 at 10% elongation, The anchoring means (6) are made of a rubber material having a tensile elastic modulus M1 at 10% elongation, and The M2 is at least equal to 0.4*M1.

21. Assembly (10) according to claim 1, wherein The single piece of the sidewall insert (9) is made of a material having a tensile elastic modulus M2 at 10% elongation, The anchoring means (6) are made of a rubber material having a tensile elastic modulus M1 at 10% elongation, and The M2 is at most equal to 5*M1.

22. The assembly (10) according to claim 1, wherein The single piece of the sidewall insert (9) has a colouration and / or a texture different from the colouration and / or the texture of at least one of the two sidewalls (3).

23. The assembly (10) according to claim 1, wherein The portion of the axially outer sidewall face (31) is flush with the rest of the axially outer sidewall face extending radially to the crown (4) from the portion of the axially outer sidewall face and extending radially to the respective bead (5) from the portion of the axially outer sidewall face.

24. The assembly (10) according to claim 1, wherein, The protrusion (8), the two recess walls (72) and the single piece of the sidewall insert (9) each have an elongated shape with a length extending in the circumferential direction (XX’) of the tyre (1).

Images