Tyre comprising a sidewall insert with non-continuous anchoring

Abstract

The tyre (1) comprising at least one sidewall (3) is intended to cooperate with a non-continuous sidewall insert, comprising at least one insert portion, by means of an anchoring means (6) comprising at least one anchoring portion (61). Each anchoring portion comprises a recess (7), formed in an outer sidewall layer and delimited by two circumferential walls, a radially inner (72) and radially outer (73) wall respectively, and a protuberance (8), in relief relative to the recess bottom. The protuberance (8) of each anchoring portion (61) comprises at least two separate protruding portions (81) distributed circumferentially along the circumferential mean line (Lm) of the anchoring portion.

Description

[0001] Tire including a discontinuous-grip sidewall insert

[0002] The present invention relates to a tire, intended more particularly for use on a light four-wheeled vehicle (car, van) or a two-wheeled vehicle (motorcycle), and comprising at least one sidewall designed to receive a sidewall insert for customizing the tire sidewall design. The invention also relates to an assembly comprising such a tire and such a sidewall insert.

[0003] A common concern of vehicle manufacturers and users is to personalize the design of tire sidewalls by means of colour and / or additional elements, such additional elements being referred to as sidewall inserts in this document.

[0004] A known method of colored rubber is a colored compound, for example, white, contained within the tire sidewall, contrasting with the black color of the adjacent rubber compounds. However, this technical solution has several drawbacks. First, certain chemical components, such as protective compounds, contained in the rubber compounds adjacent to the colored compound can migrate into the colored rubber compound and cause it to gradually discolor over time. Furthermore, sidewall deformations during the tire's lifespan can initiate cracking in the colored rubber compound and degrade its appearance. Additionally, the mechanical means used to mount the tire onto its rim, by rubbing against the colored rubber compound, can also degrade it.Finally, manufacturing a tire with sections of different colors is more complex industrially.

[0005] US patent 3128815 describes an insert in the form of a tire lining element designed to be removably engaged in a sidewall. This lining element can be attached to the sidewall by various means, such as engaging its ends in the sidewall, or hooking its ends by means of anchors 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 surface, and is positioned more specifically in the radially inner portion of the sidewall, between the outermost axial point of the sidewall and the rim edge. However, this lining element is susceptible to deformation and detachment from the sidewall during tire rolling because it is positioned in an area of ​​high tire flex.

[0006] Document JPH11151918 describes another removable colored insert intended to be fixed to the outer radial part of a tire sidewall, near the tread, by means of a recessed attachment mechanism relative to the sidewall surface. However, such an attachment mechanism does not allow for easy mounting of this insert on the tire once it is mounted on its rim and inflated, because the geometry of the insert may mismatch with the geometry of the recess in the attachment mechanism, depending on the inflation pressure or the rim width. Furthermore, during driving, the tightness of the insert on the sidewall may change, for example, under strong lateral acceleration, with a risk of the insert being ejected.

[0007] Document WO 2022069831 A1 describes a tire comprising at least one sidewall, designed to cooperate with a sidewall insert via an anchoring means, and aims to customize the design of this tire sidewall. The anchoring means, comprising a recess formed in an outer layer of the sidewall, includes a protrusion, raised above the bottom of the recess and extending from the bottom of the recess to the vicinity of the outer face of the sidewall. The protrusion has, in any meridional plane, a minimum width Lpmin in the vicinity of the bottom of the recess so as to ensure the anchoring of the sidewall insert intended to cooperate with the anchoring means. The sidewall insert described in this document allows for easier mounting and improved attachment to the sidewall.

[0008] Document WO 2022069832A1 describes a particular embodiment of a tire, as described in document WO 2022069831 A1, in which the anchoring means, comprising a hollow formed in an outer layer of sidewall, includes a protrusion, raised above the bottom of the hollow and extending from the bottom of the hollow to the vicinity of the outer face of the sidewall, and the protrusion is made up of a staggered arrangement of a first narrow portion having a minimum width Lpmin and a second wide portion having a maximum width Lpmax, such that the difference Lpmax-Lpmin is at least equal to 1 mm and at most equal to 4 mm.

[0009] Generally speaking, regardless of the type of sidewall insert as described in the aforementioned documents, its retention on the tire sidewall during tire movement is a constant concern and requires a reliable anchoring system. Furthermore, all sidewall inserts have manufacturing tolerances. For example, for a sidewall insert with a theoretical length of 2000 mm, designed to work with a tire sidewall over a circumferential anchoring system of 2000 mm, a manufacturing tolerance of 1% for the sidewall insert results in a length variation of up to 20 mm, either too short or too long. If the sidewall insert is longer than the circumferential anchoring system, the excess insert length cannot be properly seated within the system.Conversely, if the sidewall insert is shorter than the circumferential length of the anchoring device, the sidewall insert cannot fully cover the circumferential length of the anchoring device. Therefore, mounting a sidewall insert on a tire sidewall remains a delicate operation.

[0010] Therefore, the inventors set themselves the objective of proposing a tire suitable for being equipped with at least one sidewall insert, with an anchoring means facilitating the mounting of the sidewall insert and guaranteeing a satisfactory and lasting grip on the sidewall while driving.

[0011] This objective was achieved by a tire for a light vehicle, intended to be mounted on a rim, said tire being suitable for use with a sidewall insert and having a nominal cross-section of height H and an axis of rotation defining an axial direction of the tire, said tire comprising two sidewalls connecting a vertex to two beads, each intended to contact the rim. At least one of the sidewalls comprises an anchoring means, intended to cooperate with the sidewall insert and comprising at least one anchoring portion which:

[0012] - has a circumferential mean line extending in a circumferential direction around the tire,

[0013] - includes a hollow which:

[0014] - is formed in an outer layer of the flank, which is in contact with atmospheric air, extending from an outer face of the flank towards the interior of the flank, and which comprises at least one rubbery material,

[0015] - has a hollow bottom,

[0016] - is delimited by a radially inner circumferential wall, closest to the axis of rotation of the tire, and by a radially outer circumferential wall, furthest from the axis of rotation of the tire, and - has, in any meridian plane containing the axis of rotation of the tire, a depth Pc, the maximum distance measured perpendicularly between the outer face of the sidewall and the bottom of the groove, at least equal to 2 mm, and a width Le, measured at the level of the outer face of the sidewall along a line perpendicular to the two circumferential walls respectively radially inner and radially outer, at most equal to 15% of the height H of the nominal section of the tire, and

[0017] - further includes a protuberance, raised above the bottom of the hollow and extending from the bottom of the hollow to the vicinity of the outer face of the flank.

[0018] Furthermore, the protrusion of any anchor portion comprises at least two disjoint protrusion portions distributed circumferentially along the circumferential mean line of the anchor portion.

[0019] The purpose of the invention is to provide a tire in which at least one sidewall can be fitted with a substantially circumferential sidewall insert, intended to personalize the tire's design, and in which the protrusion of any anchoring portion comprises at least two disjointed protrusion portions distributed circumferentially along the circumferential mean line of the anchoring portion. In other words, this protrusion exhibits discontinuities along the circumferential mean line of the anchoring portion.

[0020] In the particular case where the side insert, intended to cooperate with a given anchorage portion, includes additional fastening means, such as, for example, pins, a first advantage of these discontinuities in the protrusion of the anchorage portion, compared to a continuous protrusion, is to allow the introduction of the additional fastening means of the side insert into all or part of the discontinuities in the protrusion of the anchorage portion, which makes it easier to manage the variations in length of the side insert, inherent in the manufacturing tolerances of the side insert, when it is placed in the anchorage portion and to ensure a more aesthetic positioning of the side insert.

[0021] In this same configuration of cooperation between a sidewall insert and its anchoring system via complementary fastening means, a second advantage is ensuring the long-term stability of the sidewall insert during tire operation. If a film of adhesive is applied between the protrusion of a given anchoring section and the sidewall insert, to guarantee better adhesion of the latter to the anchoring section, a third advantage of these discontinuities in the protrusion is better management of any excess adhesive. Indeed, when manually gluing a sidewall insert, it is not always easy to perfectly control the amount of adhesive applied to the protrusion. Excess adhesive can overflow and escape from the recess of the anchoring section, potentially creating a stain on the sidewall and / or the sidewall insert.Thus, the presence of discontinuities in the protrusion allows it to act as a reservoir and store any excess glue, preventing the glue from overflowing outside the anchoring portion and staining the side and / or the side insert.

[0022] According to a first embodiment, the anchoring means comprises a single anchoring portion that is continuous over the entire circumference of the tire. In this case, the anchoring means forms a complete ring on the sidewall of the tire.

[0023] According to a second embodiment, the anchoring means comprises at least one circumferentially delimited anchorage portion bounded by a first end wall and a second end wall. In other words, the anchoring means comprises either a single anchorage portion or a plurality of disjoint anchorage portions. In the case of a single anchorage portion, the first and second end walls of said single anchorage portion are separated from each other by a flank portion. In the case of a plurality of disjoint anchorage portions, the first and second end walls of a given anchorage portion are separated from at least one adjacent anchorage portion by a flank portion.

[0024] According to a preferred variant of the second embodiment, the anchoring means comprises at least two disjoint anchoring portions. A plurality of anchoring portions allows for anchoring portions with average circumferential lengths, measured along their average circumferential lines, that are smaller than those of a single anchoring portion, thus making them easier to mount. Furthermore, a plurality of anchoring portions allows for greater customization of the sidewall design, with the possibility of differentiating the corresponding insert portions intended to cooperate with the anchoring portions. According to an even more preferred variant, the at least two disjoint anchoring portions are circumferentially distributed along the same average circumferential line.This allows for the standardization of the manufacturing of the tire curing mold components, distributed circumferentially, as the anchor portions to be molded are always positioned on the same radius relative to the axis of rotation. Furthermore, the visual effect of the sidewall insert positioned on the same circumference is frequently desired.

[0025] However, the anchoring portions have their respective average circumferential lines not necessarily positioned on the same circumference, and can therefore be offset from each other in the height of the flank.

[0026] According to a first configuration of the anchor portion ends, the first and second end walls of at least one anchor portion are in direct interface with the protrusion of said anchor portion. In other words, the protrusion extends to the end walls, such that there is continuity between the protrusion and the end walls.

[0027] According to a second configuration of the anchor portion ends, the first and second end walls of at least one anchor portion are separated from the protrusion of said anchor portion by an end discontinuity. This end discontinuity facilitates the mounting of the opposite insert portion, particularly when the latter includes an additional end fastening means designed to cooperate with said end discontinuity.

[0028] Advantageously, the depth Pc of the recess is at least 3 mm. The recess anchors the side insert to the sidewall by locking the insert's edges between the recess walls. It therefore helps retain the side insert during driving, preventing it from being ejected. It also allows the side insert to be engaged within the thickness of the sidewall, so as not to create a significant protrusion relative to the outer face of the sidewall, and thus not to disrupt the airflow near the sidewall in this area. Consequently, the vehicle's aerodynamic drag is not increased. As a result, the vehicle's drag coefficient is not affected, and therefore fuel consumption is not increased. Preferably, the depth Pc of the recess is at least 2 mm.If the groove depth (Pc) is less than 2 mm, the anchoring device does not guarantee sufficient grip on the sidewall insert to withstand the various mechanical stresses applied to the tire during its service life. A minimum groove depth (Pc) of 3 mm further improves the retention of the sidewall insert in its anchoring device during the various rolling stresses of the tire, and allows the sidewall insert to be engaged even more deeply in the sidewall, thus further reducing aerodynamic drag and, consequently, rolling resistance.

[0029] Advantageously, the groove depth (Pc) is at most 7 mm, and preferably at most 5 mm. If the groove depth (Pc) exceeds 7 mm, the thickness of the rubber layer inside the groove bottom is insufficient to guarantee mechanical decoupling between the sidewall insert, intended to be engaged in the groove, and the outermost tire reinforcement layer. This results in stress concentrations at the bottom of the groove, which can lead to cracking and reduced sidewall durability. Furthermore, from a manufacturing perspective, a groove of limited depth ensures the presence of a sufficient thickness of rubber layer inside the groove bottom, despite significant material movement in this area during the tire manufacturing and finishing stages.In other words, a not-too-high hollow depth helps to guarantee manufacturing tolerances.

[0030] Also advantageously, the difference between the thickness W of the outer sidewall layer and the depth Pc of the cavity is at least 1 mm, preferably at least 2 mm. The thickness W is measured between the outer face of the sidewall and the reinforcements of the outermost reinforcing layer: it therefore takes into account both the outer sidewall layer itself and the outer rubber coating layer of the outermost reinforcing layer. The difference between the thickness W of the outer sidewall layer and the depth Pc of the cavity thus defines the thickness of the rubber material layer between the cavity bottom and the outermost reinforcing layer. A thickness of 1 mm is the minimum thickness of the rubber material layer, guaranteeing mechanical decoupling between the sidewall insert, intended to be engaged in the cavity, and the outermost reinforcing layer.This minimum thickness therefore prevents stress concentrations at the bottom of the groove, which could lead to cracking and a reduction in sidewall durability. Advantageously, the groove width Le is at most equal to 10% of the nominal section height H of the tire.

[0031] Advantageously, the tread width Le is at most 20 mm, preferably at most 12 mm. The tread width Le must remain limited because the larger it is, the greater the flex in the sidewall insert area during use, which generates significant deformations and potential fatigue problems in the sidewall insert. Indeed, deformations in the tread area increase with the tread width Le, which can 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 standard tire specifications, such as, for example, the European Tyre and Rim Technical Organisation (ETRTO) standard.

[0032] Advantageously, the protrusion has, in any meridional plane, a height Hp at least equal to the depth Pc of the recess minus 2 mm. The protrusion, formed within the recess from the bottom of the recess, is designed to contact an inner face of the sidewall insert and provides support for the sidewall insert. A minimum height Hp, equal to the depth Pc of the recess minus 2 mm, allows a sidewall insert to be positioned on the protrusion with sufficient bearing height while not protruding, or only slightly protruding, beyond the outer face of the sidewall. This configuration thus provides effective support for the sidewall insert while protecting it from potential sidewall scraping against curbs. Furthermore, limited penetration of the sidewall insert into the thickness of the sidewall ensures its visibility as a design element.

[0033] Furthermore, the protrusion has, in any meridional plane, a height Hp at most equal to the depth Pc of the groove plus 2 mm. A maximum height Hp, equal to the depth Pc of the groove plus 2 mm, prevents the insert from protruding beyond the outer face of the sidewall. This configuration thus avoids disrupting the airflow near the sidewall in this area. Consequently, the aerodynamic drag of the tire is not increased. As a result, the vehicle's rolling resistance, and therefore fuel consumption, is not increased. In addition, the susceptibility to potential sidewall scraping against curbs remains limited.

[0034] According to a particular embodiment of the protrusion, the protrusion is formed, in any meridional plane, by a stepped arrangement of a first narrow portion extending outwards from the bottom of the groove, and a second wide portion extending outwards from the first narrow portion. Such a protrusion thus has a shape essentially resembling a mushroom, with the base being the first narrow portion and the head being the second wide portion, which gives it, in addition to its support function, an anchoring function. This mushroom-shaped protrusion configuration allows for effective clipping of the sidewall insert onto the protrusion and ensures its retention in position during rolling, under the mechanical stresses of bending and centrifugal force applied to the tire.

[0035] The outer sidewall layer, in which the cavity is formed, extends from an outer sidewall face, in contact with the atmosphere, to an outermost reinforcing layer, most often made of textile reinforcements. More precisely, the outer sidewall layer is in internal contact with the rubber compound encasing the reinforcements of the outermost reinforcing layer, commonly called the coating compound.

[0036] Advantageously, the cavity is formed in an outer sidewall layer made of a single rubbery material. Consequently, the cavity is generally not formed in a composite layer, consisting of a superposition of materials, and therefore potentially susceptible to mechanical strength problems at the interfaces between said materials.

[0037] Advantageously, the circumferential mean line of any anchor portion is positioned, in any meridian plane, at a radial distance of at least 5%, preferably at least 10%, from the height H of the nominal section of the tire, and radially inside an axial line passing at mid-height H / 2 of the nominal section of the tire.In particular, for tires whose outermost axial point on the outer sidewall is positioned on the axial line passing through mid-height H / 2 of the nominal section of the tire, such positioning of the average circumferential line of any anchoring portion makes it possible to avoid deterioration of the sidewall insert, in particular when the sidewall is scraped against a curb. The invention also relates to an assembly comprising a tire according to any of the tire embodiments described above, and a sidewall insert comprising at least one insert portion cooperating with the anchoring portion or one of the anchoring portions of the tire anchoring means, by engaging in the hollow of the corresponding anchoring portion and bearing against the protrusion of the corresponding anchoring portion.

[0038] In practice, the ends of any insert portion coincide with the ends of the corresponding anchor portion. In other words, any insert portion and its opposite anchor portion have equal mean curvilinear lengths.

[0039] Like the anchoring means, the sidewall insert can be continuous or discontinuous. A continuous insert, intended to cooperate with the first embodiment of the tire described above, forms a complete ring when placed on the sidewall. A discontinuous insert, intended to cooperate with the second embodiment of the tire described above, comprises at least one circumferentially delimited insert portion intended to cooperate with an anchoring portion also circumferentially delimited by a first end wall and a second end wall. In other words, in this case, the sidewall insert comprises either a single insert portion intended to cooperate with a single anchoring portion, or a plurality of insert portions intended to cooperate with a plurality of disjointed anchoring portions.

[0040] According to a preferred embodiment, at least one portion of the insert comprises complementary fastening means that cooperate with:

[0041] - discontinuities formed between two consecutive protrusion portions of the corresponding anchoring portion, and / or

[0042] - the discontinuities at the end of the corresponding anchoring portion.

[0043] These additional fastening methods include, for example, pins designed to be driven into discontinuities.

[0044] In one particular embodiment, the insert portion may have a variable width near the outer face of the side. This implies a variable hollow width in the opposing anchor portion.

[0045] Preferably, the side insert comprises at least one polymeric material. This polymeric material may be chosen from a rubbery material, a silicone, or a thermoplastic material, for example, a polyurethane.

[0046] The material(s) constituting the sidewall insert must be sufficiently deformable to avoid generating excessive stresses at the interface between the sidewall insert and the anchoring device, which could induce cracking and fatigue failures in the tire sidewall. A polymeric material, such as, but not limited to, a rubber-like material, silicone, or a thermoplastic material, for example, polyurethane, meets this requirement.

[0047] The side insert is made of a material having a tensile modulus of elasticity M2 at 10% elongation and is intended to cooperate with an anchoring means made of a rubbery material having a tensile modulus of elasticity M1 at 10% elongation, where M2 is advantageously at least equal to 0.4*M1. The side insert must be sufficiently rigid to allow its placement on the side.

[0048] The sidewall insert, being made of a material with a tensile modulus of elasticity M2 at 10% elongation, and intended to cooperate with an anchoring means made of a rubbery material with a tensile modulus of elasticity M1 at 10% elongation, M2 is advantageously no more than 5*M1. The sidewall insert must not be too rigid to avoid generating excessive stresses in the tire sidewall that could damage it when subjected to bending stresses, and to reduce the risk of the sidewall insert being ejected by centrifugal force during rolling.

[0049] Advantageously, the sidewall insert has a different color and / or texture than the sidewall comprising the anchoring means. Since the objective of the invention is to personalize the design of tire sidewalls, the sidewall insert preferably has a different color and / or texture compared to the sidewall.

[0050] The side insert, preferably colored, may have one or more colors different from the usual black color of the side. Preferably, the side insert is monochrome to simplify its manufacture.

[0051] Depending on specific design variations, to further differentiate it from the side panel, the side panel insert is covered with a graphic or texture, for example of a velvet type.

[0052] In the case where the side insert comprises a plurality of insert portions, these advantageously have colours and / or textures, which are differentiated from each other, with a view to even more specific personalisation.

[0053] The features of the invention are illustrated by schematic figures 1 to 14, which are not drawn to scale: - Figure 1: Meridional half-section of a tire according to the invention, not equipped with a sidewall insert and mounted on its rim,

[0054] - Figure 2: Meridian section of an anchoring means according to the invention,

[0055] - Figure 3: Side view of a portion of a tire according to a first embodiment of a tire according to the invention, not equipped with a sidewall insert,

[0056] - Figure 4: Side view of a portion of a tire according to a first variant of a second embodiment of a tire according to the invention, not equipped with a sidewall insert,

[0057] - Figure 5: Side view of a portion of a tire according to a second variant of the second embodiment of a tire according to the invention, not equipped with a sidewall insert,

[0058] - Figure 6: Side view of the respective ends of two consecutive anchoring portions of a tire according to the second variant of the second embodiment of a tire according to the invention, not equipped with a sidewall insert,

[0059] - Figure 7: Half-cross-section of a tire according to the invention, equipped with a sidewall insert and mounted on its rim,

[0060] - Figure 8: Meridian section of an assembly of a flank insert on its anchoring means according to the invention,

[0061] - Figure 9: Side view of a portion of a tire according to the first variant of the second embodiment of a tire according to the invention, equipped with a discontinuous sidewall insert,

[0062] - Figure 10: Cross-sectional view of a portion of a tire according to the first variant of the second embodiment of a tire according to the invention, equipped with a discontinuous sidewall insert,

[0063] - Figure 11: Side view of a portion of a tire according to a first configuration of the second variant of the second embodiment of a tire according to the invention, equipped with a discontinuous sidewall insert,

[0064] - Figure 12: Cross-sectional view of a portion of a tire according to the first configuration of the second variant of the second embodiment of a tire according to the invention, equipped with a discontinuous sidewall insert, - Figure 13: Side view of a portion of a tire according to a second configuration of the second variant of the second embodiment of a tire according to the invention, equipped with a discontinuous sidewall insert, and

[0065] - figure 14: Cross-sectional view of a portion of a tire according to the second configuration of the second variant of the second embodiment of a tire according to the invention, equipped with a discontinuous sidewall insert.

[0066] Figure 1 is a meridional half-section of a tire 1 according to the invention, not equipped with a sidewall insert and mounted on a rim 2. The tire 1 for a light vehicle is mounted on the rim 2 and is suitable for being equipped with at least one sidewall insert 9 (not shown) by means of an anchoring means 6. The tire 1 has a nominal section of height H as defined by the ETRTO (European Tyre and Rim Technical Organisation) standard and comprises two sidewalls 3 connecting a vertex 4 respectively to two beads 5, each intended to come into contact with the rim 2. The sidewall 3 shown includes an anchoring means 6, intended to cooperate with a sidewall insert 9 (not shown).The anchoring means 6 extends circumferentially, along a circumferential direction XX' of the tire, and comprises a recess 7 formed in an outer layer of sidewall 30 comprising at least one rubbery material, extending from an outer face of sidewall 31 towards the interior of sidewall 3. The anchoring means 6 includes a protrusion 8, raised above the bottom of the recess and extending from the bottom of the recess to the vicinity of the outer face of sidewall 31. Furthermore, the circumferential mean line Lm of the anchoring means 6 is positioned, in the meridian plane YZ, at a radial distance d, which is at least equal to 5%, preferably at least equal to 10%, of the height H of the nominal section of the tire 1, from and radially inside an axial line D passing through a point P on the outer face of sidewall 31, at mid-height H / 2 of the nominal section of tire 1, and perpendicular to the equatorial plane XZ of tire 1.

[0067] Figure 2 is a meridional cross-section of an anchoring means 6 according to the invention. It is a detailed view of Figure 1. The anchoring means 6 comprises a recess 7 and a protrusion 8. The recess 7 is delimited internally by a recess bottom 71 and radially delimited by a radially inner circumferential wall 72, closest to the rotation axis of the tire, and by a radially outer circumferential wall 73, furthest from the rotation axis of the tire. The recess 7 has, in the meridian plane YZ containing the rotation axis YY' of the tire, a depth Pc, the maximum distance measured perpendicularly between the outer face of the sidewall 31 and the recess bottom 71, and a width Le, measured at the level of the outer face of the sidewall 31, along a line perpendicular to the two radially inner circumferential walls 72 and radially outer circumferential walls 73, respectively.The depth Pc of the groove 7 is at least 2 mm and at most 7 mm. The width Le of the groove 7 is at most 15%, preferably at most 10%, of the nominal section height H of the tire 1. Since the outer sidewall layer 30 has a thickness W at the anchoring means 6, the difference between the thickness W of the outer sidewall layer 30 and the depth Pc of the groove 7 is at least 1 mm. Furthermore, in the embodiment shown, the protrusion 8, having a height Hp, is formed, in any meridian plane YZ, by a stepped arrangement of a first narrow portion extending outwards from the bottom of the groove 71, and a second wide portion extending outwards from the first narrow portion, thus giving it a mushroom shape.

[0068] Figure 3 is a side view of a portion of a tire 1 according to a first embodiment of a tire according to the invention, not equipped with a sidewall insert. The sidewall 3 extends between the apex 4 and the bead 5. The first embodiment is characterized by an anchoring means 6 comprising a single anchoring portion 61 continuous over the entire circumference of the tire 1, this single anchoring portion 61 forming a complete ring on the sidewall of the tire. The anchoring means 6 comprises a recess 7, formed in an outer layer of the sidewall, and a protrusion 8, raised above the bottom of the recess and extending from the bottom of the recess to the vicinity of the outer face of the sidewall. According to the invention, the protrusion 8 comprises a plurality of disjointed protrusion portions 81 distributed circumferentially along the circumferential mean line Lm of the anchoring means 6.

[0069] Figure 4 is a side view of a portion of a tire 1 according to a first variant of a second embodiment of a tire according to the invention, not equipped with a sidewall insert. The second embodiment shown is characterized by an anchoring means 6 comprising a plurality of disjointed anchoring portions 61, distributed circumferentially along the same circumferential mean line Lm of the anchoring means 6. Each anchoring portion 61 is circumferentially delimited by a first end wall 74 and by a second end wall 75. In addition, each anchoring portion 61 comprises a recess 7, formed in an outer sidewall layer, and a protrusion 8, projecting from the bottom of the recess and extending from the bottom of the recess to the vicinity of the outer sidewall face.According to the invention, the protrusion 8 of any anchoring portion 61 comprises a plurality of disjointed protrusion portions 81 distributed circumferentially along the circumferential mean line of the anchoring portion 61. The first variant of this second embodiment is characterized by the fact that each anchoring portion 61 is circumferentially delimited by a first end wall 74 and a second end wall, which are in direct interface with the protrusion 8 of said anchoring portion 61. In other words, in this first variant, the protrusion 8 is extended to the end walls 74 and 75, such that there is continuity between the protrusion 8 and these end walls 74 and 75.

[0070] Figure 5 is a side view of a portion of a tire 1 according to a second variant of the second embodiment of a tire according to the invention, not equipped with a sidewall insert. This second variant of the second embodiment differs from the first variant of the second embodiment, previously described in Figure 4, in that the first and second end walls 74 and 75 of each anchoring portion 61 are separated from the protrusion 8 of said anchoring portion 61 by an end discontinuity 76.

[0071] Figure 6 is a side view of the respective ends of two consecutive anchoring portions 61 of a tire 1 according to the second variant of the second embodiment, illustrated in Figure 5, of a tire according to the invention, in which the first and second end walls 74 and 75 of each anchoring portion 61 are separated from the protrusion 8 of said anchoring portion 61 by an end discontinuity 76.

[0072] Figure 7 is a meridional half-section of a tire 1 according to the invention mounted on the rim 2 and equipped with a sidewall insert 9. It combines the tire of Figure 1 with the sidewall insert 9. The common references in Figures 7 and 1 designate the same elements.

[0073] Figure 8 is a cross-section of an assembly of a sidewall insert 9 on its anchoring means 6 according to the invention. It is a detailed view of Figure 7. The reference numerals common to Figures 8 and 2 designate the same elements. Figure 9 is a side view of a portion of a tire 1 according to the first variant of the second embodiment, as shown in Figure 4, the tire being equipped with a discontinuous sidewall insert 9. The sidewall insert 9 comprises a plurality of insert portions 91 which cooperate with a plurality of anchoring portions 61, as shown in Figure 4. Each insert portion 91 cooperates with an anchoring portion 61 by engaging this insert portion 91 in the recess 7 of the corresponding anchoring portion 61 and by bearing said insert portion 91 on the protrusion 8 of this anchoring portion 61.In addition, each portion of insert 91 includes complementary fastening means 92, of the pin type, which cooperate respectively with the discontinuities formed between two consecutive protrusion portions 81 of the anchoring portion 61. More precisely, these complementary fastening means 92 are driven into the discontinuities between two consecutive disjoint protrusion portions 81.

[0074] Figure 10 is a cross-sectional view of a portion of a tire 1 according to the first variant of the second embodiment of a tire according to the invention, as shown in Figure 9. More specifically, it is a cross-section of Figure 9 along the circumferential mean line Lm of the anchoring portions 61.

[0075] Figure 11 is a side view of a portion of a tire 1 according to a first configuration of the second variant of the second embodiment of a tire according to the invention, as shown in Figure 5, the tire being equipped with a discontinuous sidewall insert 9. The side insert 9 comprises a plurality of insert portions 91 which cooperate with a plurality of anchoring portions 61, as shown in Figures 5 and 6. Each insert portion 91 cooperates with an anchoring portion 61 by engaging this insert portion 91 in the recess 7 of the corresponding anchoring portion 61 and by bearing this insert portion 91 on the protrusion 8 of this anchoring portion 61. In addition, each insert portion 91 comprises complementary fastening means 92, of the pin type, which cooperate with the discontinuities between two consecutive protrusion portions 81 of the anchoring portion 61.More specifically, these additional fastening means 92 are inserted into the discontinuities between two consecutive disjoint protrusion portions 81. This first configuration is characterized by an insert portion 91 not including additional fastening means 92 at its end and therefore not cooperating with the end discontinuities 76.

[0076] Figure 12 is a cross-sectional view of a portion of a tire according to the first configuration of the second variant of the second embodiment of a tire according to the invention, as shown in Figure 11. More specifically, it is a cross-section of Figure 11 along the mean line of the anchoring portion.

[0077] Figure 13 is a side view of a portion of a tire 1 according to a second configuration of the second variant of the second embodiment of a tire according to the invention, as shown in Figure 5, the tire being equipped with a discontinuous sidewall insert 9. This second configuration differs from the first configuration, illustrated in Figures 11 and 12, in that each portion of insert 91 includes additional fastening means 92 at the end which cooperate with the end discontinuities 76.

[0078] Figure 14 is a cross-sectional view of a portion of a tire according to the second configuration of the second variant of the second embodiment of a tire according to the invention, as shown in Figure 13. More specifically, it is a cross-section of Figure 13 along the mean line of the anchoring portion.

[0079] The inventors have more specifically studied this invention for three types of tires: a PI tire of size 255 / 35 ZR 20, a P2 tire of size 275 / 35 ZR 21 and a P3 tire of size 305 / 30 ZR 21.

[0080] The characteristics of the three tire examples studied by the inventors are presented in Table 1 below:

[0081]

[0082] The inventors were able to observe easy assembly and satisfactory and lasting attachment to the sidewall during rolling, for a sidewall insert equipping a sidewall of a tire according to the invention.

Claims

Demands 1. A tire (1) for a light vehicle, intended to be mounted on a rim (2), said tire being capable of being fitted with a sidewall insert (9) and having a nominal cross-section of height H and an axis of rotation defining an axial direction (YY') of the tire, said tire comprising two sidewalls (3) connecting a vertex (4) respectively to two beads (5) each intended to come into contact with the rim (2), in which at least one of the sidewalls (3) comprises an anchoring means (6), intended to cooperate with the sidewall insert (9) and comprising at least one anchoring portion (61) which: - has a circumferential mean line (Lm) extending along a circumferential direction (XX') of the tire, - includes a hollow (7) which: - is formed in an outer layer of the flank (30) of the flank (3), which is in contact with atmospheric air, extending from an outer face of the flank (31) towards the interior of the flank (3), and which comprises at least one rubbery material, - has a hollow bottom (71), - is delimited by a radially inner circumferential wall (72), closest to the axis of rotation of the tire, and by a radially outer circumferential wall (73), furthest from the axis of rotation of the tire, and - a, in any meridian plane (YZ) containing the axis of rotation of the tire, a depth Pc, the maximum distance measured perpendicularly between the outer face of the sidewall (31) and the bottom of the groove (71), of at least 2 mm, and a width Le, measured at the level of the outer face of the sidewall (31) along a line perpendicular to the two circumferential walls respectively radially inner (72) and radially outer (73), at most equal to 15% of the height H of the nominal section of the tire (1), and - further includes a protrusion (8), raised above the bottom of the hollow (71) and extending from the bottom of the hollow (71) to the vicinity of the outer face of the flank (31), and in which the protrusion (8) of any anchoring portion (61) includes at least two disjointed protrusion portions (81) distributed circumferentially along the circumferential mean line (Lm) of the anchoring portion (61).

2. Pneumatic (1) according to claim 1, wherein the anchoring means (6) comprises a single anchoring portion (61) which is continuous over the entire circumference of the pneumatic.

3. Pneumatic (1) according to claim 1, wherein at least one anchoring portion (61) is circumferentially delimited by a first end wall (74) and by a second end wall (75).

4. Pneumatic (1) according to claim 3, wherein the first and second end walls (74, 75) of at least one anchoring portion (61) are in direct interface with the protrusion (8) of said anchoring portion (61).

5. Pneumatic (1) according to claim 3, wherein the first and second end walls (74, 75) of at least one anchoring portion (61) are separated from the protrusion (8) of said anchoring portion (61) by an end discontinuity (76).

6. Pneumatic (1) according to any one of claims 1 and 3 to 5, wherein the anchoring means (6) comprises at least two disjoint anchoring portions (61).

7. Pneumatic (1) according to claim 6, wherein the at least two disjoint anchoring portions (61) are distributed circumferentially along the same circumferential mean line (Lm).

8. Assembly (10), comprising a tire (1) according to any one of claims 1 to 7 and a sidewall insert (9) comprising at least one insert portion (91) cooperating with the anchoring portion (61) or one of the anchoring portions (61) of the anchoring means (6) of the tire (1), by engaging in the hollow (7) of the corresponding anchoring portion (61) and bearing against the protrusion (8) of the corresponding anchoring portion (61).

9. Assembly (10) according to claim 8, wherein the tire conforms to one of claims 6 or 7, and wherein at least one insert portion (91) comprises complementary fastening means (92) which cooperate with the discontinuities formed between two consecutive protrusion portions (81) of the corresponding anchoring portion (61).

10. Assembly (10) according to claim 8 or 9, wherein the tire conforms to claim 5, and wherein at least a portion insert (91) includes complementary fastening means (92) which cooperate with the end discontinuities (76) of the corresponding anchoring portion (61).

11. Assembly (10) according to any one of claims 8 to 10, wherein one side insert (9) comprises a plurality of insert portions (91) having colours and / or textures, which are differentiated between the insert portions (91) of said plurality.

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