Tyre comprising a durable stiffening structure and an interface between outer and inner layers

Abstract

The invention relates to a tyre (10) comprising: a crown (12); first and second sidewalls (30A, 30B); first and second beads (32A, 32B); an internal surface (34) which defines a toroidal cavity (36); a first outer layer (33A) which is arranged radially and / or axially outside a first inner layer (37A) and is in contact with the first inner layer (37A); and a stiffening structure (52) which extends continuously in the toroidal cavity (36) from the first sidewall (30A) and / or bead (32A) to the crown (12), passes through the first inner layer (37A) and at least partially penetrates the first outer layer (33A). A modulus ratio between a nominal secant modulus at 10% elongation of the first outer layer (33A) and a nominal secant modulus at 10% elongation of the first inner layer (37A) is strictly greater than 1.0.

Description

[0001] Tire comprising a durable stiffening structure and an interface between outer and inner layers

[0002] Technical field

[0003] The present invention relates to a tire, in particular for a passenger vehicle.

[0004] A tire is understood to mean a bandage intended to form a cavity by cooperating with a mounting support, for example a rim, this cavity being capable of being pressurized to a pressure higher than atmospheric pressure. A tire has a structure of substantially toroidal shape of revolution around a main axis of the tire, this main axis being coincident with the axis of rotation of the tire.

[0005] Previous techniques

[0006] Known from the state of the art is a tire intended to equip a passenger vehicle and described in WO2020 / 128225. The tire described comprises a crown extended radially inwards respectively on each side of the median plane of the tire by first and second sidewalls then by first and second beads intended to come into contact with a mounting support, for example a rim. Each first and second bead comprises a circumferential reinforcing element intended to allow the tire to be attached to the mounting support.

[0007] The tire includes an internal surface delimiting a toric cavity for inflating the tire once the latter is mounted on the mounting support.

[0008] The tire described in WO2020 / 128225 comprises a stiffening structure comprising first stiffening elements extending continuously in the toric cavity from the first bead to the crown and second stiffening elements extending continuously in the toric cavity from the second bead to the crown.

[0009] Each first and second stiffening element is secured to each bead from which it extends by a bead interface between the stiffening element and a portion of the inner surface of the bead. Similarly, each first and second stiffening element is secured to the crown of the tire by a crown interface between the stiffening element and a portion of the inner surface of the crown. Each bead and crown interface comprises a cushion of elastomeric mixture positioned between the stiffening element and the portion of the corresponding inner surface.

[0010] It was noted that each bead and crown interface was subjected to tensile stress. Such interfaces are sensitive to repeated stresses which can lead to early debonding between the stiffening elements and the inner surface of the bead and / or the inner surface and therefore to early destruction of the stiffening structure.

[0011] The endurance of the tire described in WO2020 / 128225 was improved in WO2022 / 200717 by using an anchoring of each first and second stiffening element in the internal structure of the tire. However, the endurance of the tire described in WO2022 / 200717, in particular the endurance of the anchoring of the first and second stiffening elements in each first sidewall and / or bead and second sidewall and / or bead, although largely improved compared to that of the tire described in WO2020 / 128225, proved to be improvable. Indeed, it was noted that the stiffening structure deteriorated due to the loosening of the stiffening elements in one of the first and second beads.

[0012] The invention aims to improve the endurance of the stiffening structure described in WO2020 / 128225 and to reduce the occurrence of loosening of the stiffening elements of the tire described in WO2022 / 200717.

[0013] Statement of the invention

[0014] The invention relates to a tire comprising a crown, first and second sidewalls each extending the crown radially inwards, first and second beads respectively extending the first and second sidewalls radially inwards, the tire being provided with an internal surface delimiting a toric inflation cavity of the tire, the tire comprising

[0015] - a first inner layer forming at least part of the first sidewall and / or bead and / or the top,

[0016] - a first outer layer forming at least in part the first sidewall and / or bead and / or the crown, and arranged radially and / or axially outside the first inner layer while being in contact with the first inner layer,

[0017] - a stiffening structure extending continuously in the toric cavity from at least the first sidewall and / or bead to at least the crown and being anchored in the first sidewall and / or bead and / or in the crown by extending in the first sidewall and / or bead and / or the crown, said stiffening structure passing through the first inner layer and penetrating at least in part the first outer layer in the first sidewall and / or bead and / or the crown, tire in which a first modulus ratio between a nominal secant modulus at 10% elongation of the first outer layer and a nominal secant modulus at 10% elongation of the first inner layer is strictly greater than 1.0.

[0018] As explained below, the invention works as soon as it is applied to only one side of the tire, here at least on the side comprising the first sidewall and / or bead. Advantageous embodiments teach that the invention can also be applied to both sides of the tire without this being necessary to carry out the invention. Thus, in the present application, the use of the qualifier "first" or "first" aims, unless there is an obvious different interpretation, to associate the element qualified as "first" or "first" with the first sidewall and / or bead. Similarly, the use of the qualifier "second" aims, unless there is an obvious different interpretation, to associate the element qualified as "second" with the second sidewall and / or bead.

[0019] Advantageously, the first sidewall and / or bead is arranged on the same side of the median plane of the tire as the outer side of the tire. Thus, the stiffening structure acts on the side of the tire that is most stressed during high drift stresses. By inner and outer sides, we mean that the tire is designed so that one of its sides is arranged on the inner side and the other of its sides is arranged on the outer side. This orientation imposed by the tire manufacturer ensures that the tire has the expected operation. Indeed, mounting a tire with an orientation different from that imposed by the manufacturer can lead to suboptimal behavior of the vehicle. By outer side, we mean the side of the tire that is entirely visible from the outside of the vehicle when the tire is mounted on the vehicle.The inner side refers to the side of the tire facing the wheel arch of the vehicle on which it is mounted. Typically, the tire has a marking indicating the inner side and the outer side.

[0020] In a preferred embodiment in which the stiffening structure performs its function on either side of the median plane of the tire, which makes it possible to obtain homogeneous behavior of the tire, the tire comprises:

[0021] - a second inner layer forming at least part of the second sidewall and / or bead and / or the top,

[0022] - a second outer layer forming at least in part the second sidewall and / or bead and / or the crown, and arranged radially and / or axially outside the second inner layer while being in contact with the second inner layer, the stiffening structure extending continuously in the toric cavity from at least the second sidewall and / or bead to at least the crown and being anchored in the second sidewall and / or bead and / or in the crown while extending in the second sidewall and / or bead and / or in the crown, said stiffening structure passing through the second inner layer and penetrating at least in part the second outer layer in the second sidewall and / or bead and / or the crown, a second modulus ratio between a nominal secant modulus at 10% elongation of the second outer layer and a nominal secant modulus at 10% elongation of the second inner layer is strictly greater than 1 ,0.

[0023] The nominal secant modulus measurements at 10% elongation are the elastic moduli of the layer compositions measured during a uniaxial tensile experiment, at an elongation value of 0.1 (i.e. 10% elongation, expressed as a percentage). A constant uniaxial tensile speed is imposed on the specimen, and its elongation and stress are measured. The measurement is carried out using an INSTRON type tensile testing machine, at a temperature of 23 °C, and a relative humidity of 50% (ISO 23529 standard). The conditions for measuring and using the results to determine the elongation and stress are as described in standard NF ISO 37: 2012-03. The stress is determined for an elongation of 0.1 and the modulus of elasticity under tension at 10% elongation is calculated by dividing this stress value by the elongation value.The person skilled in the art will know how to choose and adapt the dimensions of the test piece according to the quantity of composition accessible and available, particularly in the case of taking samples from the tire.

[0024] The nominal secant modulus at 10% of the inner layer strictly lower than the nominal secant modulus at 10% of the corresponding outer layer makes it possible to dilute the stresses generated by the stiffening structure at the point of penetration of the stiffening structure into said inner layer, and thus reduces crack initiation at the point of penetration of the stiffening structure into said inner layer.

[0025] Each outer layer, more rigid than the corresponding inner layer, makes it possible to absorb the movements and therefore the forces generated by the stiffening structure on the said outer layer concerned and thus to obtain a more durable anchoring of the stiffening structure.

[0026] This stiffness gradient induced by the combination of the inner layer having a relatively low stiffness compared to the relatively higher stiffness of the outer layer with which the inner layer is in contact makes it possible to limit, or even eliminate, the loosening of the stiffening elements and therefore to improve the endurance of the stiffening structure. Thus, an anchor according to the invention is significantly more robust than the bead interfaces described in WO2020 / 128225 and makes it possible to eliminate the loosening by loosening of the stiffening structure described in WO2022 / 200717.

[0027] An additional advantage of the invention lies in the fact that even when hot, for example due to very demanding use of the tire, even if each nominal secant modulus at 10% elongation decreases, the modulus ratio is kept strictly greater than 1.0, which makes it possible to maintain the effect of the invention even for relatively high temperatures.

[0028] In a preferred embodiment, each first and second inner layer respectively comprising a first and second inner composition, the first and second inner compositions are identical. Thus, the nominal secant modulus at 10% of the first inner layer is equal to the nominal secant modulus at 10% of the second inner layer. Alternatively, it may be imagined that the first and second inner compositions are different and therefore that the nominal secant modulus at 10% of the first inner layer is different from the nominal secant modulus at 10% of the second inner layer.

[0029] Similarly, each first and second outer layer comprising respectively a first and second outer composition, the first and second outer compositions are identical. Thus, the nominal secant modulus at 10% of the first outer layer is equal to the nominal secant modulus at 10% of the second outer layer. Alternatively, it may be imagined that the first and second outer compositions are different and therefore that the nominal secant modulus at 10% of the first outer layer is different from the nominal secant modulus at 10% of the second outer layer. Thus, it may be possible to have embodiments in which the first modulus ratio is equal to the second modulus ratio.It will also be possible to envisage embodiments in which the first module ratio is strictly greater than the second module ratio, which is particularly advantageous in the case where the first sidewall and / or bead is arranged on the same side of the median plane of the tire as the outer side of the tire for the reasons explained previously.

[0030] In embodiments, the stiffening structure comprises at least one first stiffening element extending continuously in the toric cavity from at least the first flank and / or bead to at least the crown and being anchored in the first flank and / or bead and / or in the crown while extending in the first flank and / or bead and / or the crown, said first stiffening element passing through the first inner layer and penetrating at least partially the first outer layer.

[0031] Optionally, the stiffening structure comprises at least one second stiffening element extending continuously in the toric cavity from at least the second flank and / or bead to at least the crown and being anchored in the second flank and / or bead and / or in the crown while extending in the second flank and / or bead and / or the crown, said second stiffening element passing through the second inner layer and penetrating at least partially the second outer layer.

[0032] By anchored in a sidewall and / or bead and / or in the crown, we mean that the stiffening structure or the stiffening element penetrates the sidewall and / or bead and / or the crown, that is to say that the stiffening structure or the stiffening element passes through the internal surface to be anchored in a sidewall and / or bead and / or in the crown.

[0033] The stiffening structure or stiffening element passes through a layer when it passes through the entire thickness of said layer in contact with said layer. The stiffening structure or stiffening element penetrates at least part of a layer when it passes into said layer in contact with said layer without necessarily leaving it. Thus, the stiffening structure or stiffening element penetrating a layer may pass through said layer. Alternatively, the stiffening structure or stiffening element penetrating a layer may pass only through a part of the layer and thus not pass through it.

[0034] The toric inflation cavity is intended to be pressurized by an inflation gas once the tire is mounted on a mounting support, most often a rim.

[0035] Among other advantages, the stiffening structure makes it possible to simultaneously increase the radial stiffness, the axial stiffness and the drift stiffness of the tire compared to a conventional tire not comprising a stiffening structure but also compared to tires comprising other stiffening structures, such as that described in WO2017 / 005713.

[0036] By increasing the radial rigidity, the stiffening structure limits the radial deformation of the crown, during rolling, and in particular, the counter-deflection, that is to say the radial deformation, opposite the contact area of ​​the rolling surface in contact with the ground. Thus, during the rolling of the tire, during the wheel revolution, the stiffening structure makes it possible to limit the amplitude of the cyclic deformations of the tire, and in particular of its tread, and therefore to limit the resulting energy dissipation, which contributes to the reduction of the rolling resistance. In addition, under radial stress, the value of the contact area with the ground is not modified, which makes it possible to maintain the same grip performance as for the tire described in WO2017 / 005713.

[0037] By increasing the axial rigidity and the drift rigidity, the stiffening structure will contribute to improving the behavior under transverse stress, for example when drifting. In addition, under transverse stress, the contact area with the ground guarantees a more homogeneous distribution of contact pressures, which makes it possible to increase the transverse grip. Furthermore, the stiffening structure participates at least partially in carrying the load applied to the tire such that this applied load is taken up jointly by the tire, thanks to its pneumatic rigidity and its intrinsic structural rigidity and by the stiffening structure. Thus, when the tire is subjected to a nominal radial load, a part of the stiffening structure arranged opposite the contact area is put under tension.In certain embodiments, conversely, a portion of the stiffening structure arranged at the contact area is subjected to compression buckling.

[0038] The presence of the stiffening structure thus makes it possible to reduce the tire's contribution to carrying the load and therefore to be able to reduce its structural rigidity, for example by reducing the volume of the beads. Indeed, the beads of a conventional tire dissipate a significant quantity of energy, due to their volume and the hysteretic nature of their constituent elastomeric mixture. Reducing their volume thus makes it possible to significantly reduce rolling resistance.

[0039] The tire according to the invention has a substantially toric shape around an axis of revolution substantially coincident with the axis of rotation of the tire. This axis of revolution defines three directions conventionally used by those skilled in the art: an axial direction, a circumferential direction and a radial direction.

[0040] By axial direction is meant the direction substantially parallel to the axis of revolution of the tire, that is to say the axis of rotation of the tire.

[0041] Circumferential direction means the direction which is substantially perpendicular to both the axial direction and a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

[0042] By radial direction is meant the direction along a radius of the tire, that is to say any direction intersecting the axis of rotation of the tire and substantially perpendicular to this axis. By median plane of the tire, noted M, is meant the plane perpendicular to the axis of rotation of the tire which is located at the axial mid-distance of the two beads and passes through the axial center of the crown reinforcement.

[0043] By equatorial circumferential plane of the tire, denoted E, is meant, in a meridian section plane, the plane passing through the equator of the tire, perpendicular to the median plane and to the radial direction. The equator of the tire is, in a meridian section plane (plane perpendicular to the circumferential direction and parallel to the radial and axial directions) the axis parallel to the axis of rotation of the tire and located equidistant between the radially outermost point of the tread intended to be in contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example a rim.

[0044] By meridian plane is meant a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0045] By radially inner, respectively radially outer, is meant closer to the axis of rotation of the tire, respectively further from the axis of rotation of the tire. By axially inner, respectively axially outer, is meant closer to the median plane of the tire, respectively further from the median plane of the tire.

[0046] By bead is meant the radial portion of the tire intended to allow the tire to be attached to a mounting support, for example a wheel comprising a rim. Thus, each bead is in particular intended to be in contact with a hook of the rim allowing it to be attached. The bead is thus delimited radially internally by the radially inner end of the tire and radially externally by an axial straight line passing through the radially outermost point in contact with a standard rim within the meaning of the European Tire and Rim Technical Organization or "ETRTO" standard, 2023. By sidewall is meant the radial portion of the tire connecting the bead to the crown. The sidewall is delimited radially externally by an edge of the tread. The axial edges of the tread are determined on a tire mounted on a nominal rim and inflated to the nominal pressure within the meaning of the ETRTO 2023 standard manual.The edges are arranged on either side of the median plane of the tire and formed by lines substantially parallel to the circumferential direction of the tire. In the case of an obvious boundary between the tread and the sidewall of the tire, the edges are determined simply. In the case where the tread is continuous with the sidewalls, the edges are usually determined by loading the tire to 80% of its load capacity according to the ETRTO 2023 standard manual and the edges are identified as the axial limits of the tread in contact with the ground. The sidewall is delimited radially internally by an axial line passing through the radially outermost point in contact with a standard rim within the meaning of the European Tire and Rim Technical Organization or "ETRTO" standard, 2023.

[0047] Any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​from more than a to less than b (i.e., excluding the limits a and b), while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​from a to b (i.e., including the strict limits a and b).

[0048] The tires of the invention are preferably intended for passenger vehicles as defined within the meaning of the European Tire and Rim Technical Organization or "ETRTO" standard, 2023. Such a tire has a section in a meridian cutting plane characterized by a section height H and a nominal section width SW within the meaning of the European Tire and Rim Technical Organization or "ETRTO" standard, 2023. The values ​​of SW and H are indicated on the marking of the sidewall of the tire, for example as defined according to the ETRTO manual, 2023.

[0049] Preferably, the passenger vehicle tires to which the invention will be advantageously applied are such that the H / S ratio, expressed as a percentage, is at most equal to 90 and at least equal to 20, and the nominal section width SW is at least equal to 115 mm and at most equal to 385 mm. In addition, the hook diameter D, defining the diameter of the rim on which the tire is mounted, is at least equal to 12 inches and at most equal to 30 inches.

[0050] Conventionally, in a tire comprising a crown reinforcement and a carcass reinforcement, the crown comprises a tread intended to come into contact with the rolling ground and a crown reinforcement arranged radially inside the tread. The carcass reinforcement is anchored in each bead and extends radially in each sidewall and axially in the crown radially inside the crown reinforcement. Conventionally, the crown reinforcement comprises at least one crown layer comprising reinforcing elements. These reinforcing elements are preferably textile or metal wire elements.

[0051] In embodiments allowing the performance of so-called radial tires to be obtained as defined by the ETRTO, the carcass reinforcement comprises at least one carcass layer, said carcass layer comprising carcass wire reinforcement elements, each carcass wire reinforcement element extending substantially in a main direction forming with the circumferential direction of the tire, an angle, in absolute value, ranging from 80° to 90°. As a variant, it will be possible to have a variable angle ranging from 80° to 90° in at least one part of the sidewall and strictly less than 80° in at least one part of the crown.

[0052] In an advantageous embodiment, the stiffening structure is not sealed against an inflation gas of the tire. Thus, the stiffening structure allows the inflation gas to pass through. In other words, the stiffening structure does not delimit a secondary cavity under pressure of the tire. By "not sealed", it will be understood that the stiffening structure is permeable to the inflation gas so that the pressure is homogeneous in the toric cavity at all times and, in particular during inflation of the tire. Advantageously, the first modulus ratio is greater than or equal to 2.0, preferably greater than or equal to 3.0.

[0053] Optionally, the second modulus ratio is greater than or equal to 2.0, preferably greater than or equal to 3.0.

[0054] A relatively high modulus ratio makes it possible to further reduce crack initiation at the point of penetration of the stiffening structure into the relevant inner layer and / or to absorb more stress in the relevant outer layer.

[0055] Preferably, the first modulus ratio is less than 20.0, preferably less than or equal to 15.0, more preferably less than or equal to 10.0 and even more preferably less than or equal to 7.0.

[0056] Optionally, the second modulus ratio is less than 20.0, preferably less than or equal to 15.0, more preferably less than or equal to 10.0 and even more preferably less than or equal to 7.0.

[0057] Too high a modulus ratio would mean that, for a given inner layer, the outer layer concerned has a relatively high rigidity which leads to high fragility (or low ductility) of the outer layer concerned. This creates a risk of breakage of the outer layer concerned due in particular to the tensioning of the stiffening structure when entering the contact area, when passing through the contact area (in particular when drifting), when leaving the contact area and when passing away from the contact area of ​​the portion of the tire comprising the portion of the stiffening structure.

[0058] Advantageously, the nominal secant modulus at 10% elongation of the first outer layer is greater than or equal to 5 MPa.

[0059] Optionally, the nominal secant modulus at 10% elongation of the second outer layer is greater than or equal to 5 MPa. Advantageously, the nominal secant modulus at 10% elongation of the first outer layer is less than or equal to 60 MPa, preferably less than or equal to 20 MPa.

[0060] Optionally, the nominal secant modulus at 10% elongation of the second outer layer is less than or equal to 60 MPa, preferably less than or equal to 20 MPa.

[0061] In particularly preferred embodiments, the modulus at 10% extension of the first inner layer is less than or equal to 8 MPa, preferably less than or equal to 5 MPa.

[0062] In particularly preferred embodiments, the modulus at 10% extension of the second inner layer is less than or equal to 8 MPa, preferably less than or equal to 5 MPa.

[0063] Such rigidity is relatively low and allows to absorb the stresses induced by the stiffening structure on the inner layer concerned. Thus, the endurance of the stiffening structure is improved.

[0064] Advantageously, the nominal secant modulus at 10% elongation of the first and / or second inner layer may be greater than or equal to 1 MPa.

[0065] Advantageously, the thickness of the first and / or second inner layer may be greater than or equal to 0.1 mm and / or less than or equal to 5 mm, preferably greater than or equal to 0.1 mm and / or less than or equal to 2 mm.

[0066] Advantageously, the thickness of the first and / or second outer layer may be greater than or equal to 2 mm and / or less than or equal to 10 mm.

[0067] Such thicknesses of the inner and outer layers make it possible to absorb the deformations and to take up the forces exerted by the stiffening structure in the outer and inner layers. A person skilled in the art will be able to determine the optimal thicknesses of each of the inner and outer layers, in particular depending on the rigidities of each of these layers.

[0068] In a first design, the first inner layer at least partly forms the inner surface, said stiffening structure penetrating the first inner layer at a first radially inner and / or outer anchoring point of the first inner layer arranged in the first sidewall and / or bead and / or the crown.

[0069] In embodiments using a first stiffening element, said first stiffening element penetrates the first inner layer at the first radially inner and / or outer anchoring point of the first inner layer arranged in the first sidewall and / or bead and / or the crown.

[0070] Optionally, in this first design, the second inner layer at least partly forms the inner surface, said stiffening structure penetrating the second inner layer at a second radially inner and / or outer anchoring point of the second inner layer arranged in the second sidewall and / or bead and / or the crown.

[0071] In embodiments using a second stiffening element, said second stiffening element penetrates the second inner layer at the second radially inner and / or outer anchoring point of the second inner layer arranged in the second sidewall and / or bead and / or the crown.

[0072] According to the first design, each first and / or second inner layer is in contact at least locally with said stiffening structure respectively at the first and / or second radially inner and / or outer anchoring point.

[0073] In embodiments using first and / or second stiffening elements, each first and / or second inner layer is in contact at least locally respectively with said first and / or second stiffening element at the first and / or second radially inner and / or outer anchoring point.

[0074] In a first variant, the entirety of the first inner layer forms at least part of the inner surface.

[0075] Optionally, the entire second inner layer forms at least part of the inner surface. Thus, no layer covers the first and / or second inner layer which is entirely in contact with the inflation gas when the tire is inflated.

[0076] In a first configuration of this first variant, the first and / or second inner layer is a sealing layer for at least one inflation gas. Optionally, the sealing layer of the first and / or second inner layer comprises a sealing composition comprising one or more butyl rubbers. More preferably, the sealing composition of the first and / or second inner layer comprises at least 50 pce of the butyl rubber(s).

[0077] The layer is called a sealing layer because of its low permeability to the inflation gas of the tire. Such a sealing layer is such that the tire without the sealing layer has higher permeability compared to a tire provided with the sealing layer.

[0078] The term "part per cent of elastomer" or "pce" means the part by weight of a constituent per 100 parts by weight of the elastomer(s), i.e. of the total weight of the elastomer(s). Thus, a constituent at 60 pce will mean, for example, 60 g of this constituent per 100 g of elastomer. Usually in the present application, the terms "elastomer" and "rubber" are used interchangeably in the text, as they are interchangeable.

[0079] Butyl rubber means a homopolymer of isobutylene or a copolymer of isobutylene and isoprene, as well as halogenated derivatives, in particular generally brominated or chlorinated, of these homopolymers of isobutylene and copolymers of isobutylene and isoprene. In a particularly preferred manner, the butyl rubber(s) that can be used in the composition are chosen from isobutylene rubbers, copolymers of isobutylene and isoprene (IIR), bromobutyl rubbers such as bromobutylene-isoprene copolymer (BIIR) and chlorobutyl rubbers such as chloroisobutylene-isoprene copolymer (CIIR). By extension of the previous definition, the term "butyl rubber" will also include copolymers of isobutylene and styrene derivatives such as copolymers of isobutylene and brominated methylstyrene (BIMS) which include the elastomer called EXXPRO marketed by the Exxon company.

[0080] As other elastomers present in the sealing composition in addition to the butyl rubber(s), mention may in particular be made of diene elastomers other than the butyl elastomers previously mentioned. By diene elastomer or rubber, one must be understood, in a known manner, one or more elastomers derived at least in part (i.e.; a homopolymer or a copolymer) from diene monomers (monomers bearing two carbon-carbon double bonds, conjugated or not). Such diene elastomers are known to those skilled in the art and for example described in WO2016 / 001226A1.

[0081] In a second configuration of this first variant, the first and / or second inner layer is not a sealing layer for at least one inflation gas. In this second configuration, the sealing performance of the tire is reduced, which, for certain sporting uses, does not in any way penalize the operation of the tire given its relatively short service life. Nevertheless, weakening the anchoring of the stiffening structure at the first and / or second radially inner and / or outer anchoring point is avoided.

[0082] In this second configuration, the first and / or second inner layer then comprises an elastomeric composition comprising less than 50 phr of butyl rubber, preferably less than 10 phr of butyl rubber and is more preferably substantially free of butyl rubber. Preferably, the elastomeric composition of each first and / or second inner layer comprises at least 50 phr of a diene elastomer. The elastomeric composition is said to be elastomeric because it is based on an elastomeric composition, this elastomeric composition being able to comprise one or more elastomers but also fillers and other components usually used in the field of tire compositions. Thus, the risk of poor adhesion between the stiffening structure and the inner layer concerned is reduced.In fact, butyl rubber has relatively weak adhesion to the stiffening structure, which creates, in the tire, a singular zone conducive to the initiation of cracks at the level of the anchorage in the sidewall and / or bead and / or the crown.

[0083] In a second variant of the first design, the tire comprises a first inner complementary layer forming at least in part the first sidewall and / or bead and / or the crown and arranged radially and / or axially inside the first inner layer, the first inner complementary layer forming at least in part the internal surface, the first inner complementary layer is arranged at a distance from said first radially inner and / or outer anchoring point of the stiffening structure.

[0084] In embodiments using a first stiffening element, the first inner complementary layer is arranged at a distance from said first radially inner and / or outer anchoring point of the first stiffening element.

[0085] Optionally, the tire comprises a second inner complementary layer forming at least in part the first sidewall and / or bead and / or the crown and arranged radially and / or axially inside the second inner layer, the second inner complementary layer forming at least in part the internal surface, the second inner complementary layer is arranged at a distance from said first radially inner and / or outer anchoring point of the stiffening structure.

[0086] In embodiments using a second stiffening element, the second inner complementary layer is arranged at a distance from said second radially inner and / or outer anchoring point of the second stiffening element.

[0087] By distance, it is understood that the sealing layer is not in contact with the stiffening structure or the stiffening element at the anchoring point concerned. The minimum distance between the sealing layer and the anchoring point concerned is determined by the person skilled in the art depending on the mastery of the tire manufacturing process but also depending on the desired sealing performance.

[0088] Preferably, the minimum distance between the sealing layer and said first and / or second radially inner and / or outer anchoring point is greater than or equal to 1 mm, preferably 5 mm.

[0089] In this second variant of the first design, the stiffening structure or stiffening element concerned does not pass through or penetrate the corresponding inner complementary layer.

[0090] Preferably, the first and / or second inner complementary layer is respectively in contact with the first and / or second inner layer.

[0091] Advantageously, the first and / or second inner complementary layer is a sealing layer against at least one inflation gas.

[0092] The sealing layer being arranged at a distance from the radially inner and / or outer anchoring point, the latter ensures the sealing function without weakening the anchoring of the stiffening structure to the radially inner and / or outer anchoring point, whether due to high rigidity of the sealing layer or due to poor adhesion of the stiffening structure or the stiffening element to the sealing layer.

[0093] Optionally, the sealing layer comprises a sealing composition comprising one or more butyl rubbers.

[0094] More preferably, the sealing composition comprises at least 50 phr of the butyl rubber(s). Thus, the butyl rubber(s) usable in the composition represent at least 50 phr, i.e. they represent at least 50% by weight of the total weight of the elastomer(s). In a second design, the tire comprises a first inner complementary layer forming at least in part the first sidewall and / or bead and / or the crown and arranged radially and / or axially inside the first inner layer, the first inner complementary layer forming at least in part the inner surface, said stiffening structure passing through the first inner complementary layer and penetrating the first inner complementary layer at a first radially inner and / or outer anchoring point of the first inner complementary layer arranged in the first sidewall and / or bead and / or the crown.

[0095] In embodiments using a first stiffening element, said first stiffening element passes through the first inner complementary layer and penetrates the first inner complementary layer at the first radially inner and / or outer anchoring point of the first inner complementary layer arranged in the first sidewall and / or bead and / or the crown.

[0096] Optionally, the tire comprises a second inner complementary layer forming at least in part the second sidewall and / or bead and / or the crown and arranged radially and / or axially inside the second inner layer, the second inner complementary layer forming at least in part the internal surface, said stiffening structure passing through the second inner complementary layer and penetrating the second inner complementary layer at a second radially inner and / or outer anchoring point of the second inner complementary layer arranged in the second sidewall and / or bead and / or the crown.

[0097] In embodiments using a second stiffening element, said second stiffening element passes through the second inner complementary layer and penetrates the second inner complementary layer at the second radially inner and / or outer anchoring point of the second inner complementary layer arranged in the second sidewall and / or bead and / or the crown.

[0098] According to the second design, each first and / or second inner complementary layer is in contact at least locally with said stiffening structure respectively at the first and / or second radially inner and / or outer anchoring point.

[0099] In embodiments using first and / or second stiffening elements, each first and / or second inner complementary layer is in contact at least locally respectively with said first and / or second stiffening element at the first and / or second radially inner and / or outer anchoring point.

[0100] In a first variant, the first and / or second inner complementary layer is a sealing layer for at least one inflation gas. Optionally, the sealing layer of the first and / or second inner complementary layer comprises a sealing composition comprising one or more butyl rubbers. More preferably, the sealing composition of the first and / or second inner complementary layer comprises at least 50 pce of the butyl rubber(s).

[0101] In a second variant, the first and / or second inner complementary layer is a layer which is not a sealing layer to at least one inflation gas. Preferably, in this second variant, the first and / or second inner complementary layer then comprises an elastomeric composition comprising less than 50 phr of butyl rubber, preferably less than 10 phr of butyl rubber and is more preferably substantially free of butyl rubber. Preferably, the elastomeric composition of each first and / or second inner layer comprises at least 50 phr of a diene elastomer. The elastomeric composition is said to be elastomeric because it is based on an elastomeric composition, this elastomeric composition possibly comprising one or more elastomers but also fillers and other components usually used in the field of tire compositions.Thus, as explained previously, the risk of poor adhesion between the stiffening structure and the inner layer concerned is reduced.

[0102] Whatever the variant, preferably, a ratio of complementary modules between a nominal secant modulus at 10% elongation of the first inner layer and a nominal secant modulus at 10% elongation of the first inner complementary layer is strictly greater than 1.0, preferably greater than or equal to 2.0.

[0103] Optionally, a ratio of complementary moduli between a nominal secant modulus at 10% elongation of the second inner layer and a nominal secant modulus at 10% elongation of the second inner complementary layer is strictly greater than 1.0, preferably greater than or equal to 2.0.

[0104] Thus, the same stiffness gradient mechanism described previously with reference to the inner and outer layers is applied to the complementary inner and inner layers.

[0105] However, it is possible to imagine a complementary modulus ratio between a nominal secant modulus at 10% elongation of the first and / or second inner layer and a nominal secant modulus at 10% elongation of the first and / or second inner complementary layer less than or equal to 1.0. Indeed, even if a crack initiation appears at the point of penetration of the stiffening structure or the stiffening element into the inner complementary layer concerned, the modulus ratio of the invention will make it possible to prevent the propagation of the crack in the inner and outer layers.

[0106] In one embodiment, the tire comprises a first anchoring member arranged in the toric cavity and extending projecting from the first sidewall and / or bead towards the interior of the toric cavity and / or from the crown towards the interior of the toric cavity while being in contact at least locally with said stiffening structure.

[0107] In embodiments using a first stiffening element, the first anchoring member projects from the first flank and / or bead towards the interior of the toric cavity and / or from the top towards the interior of the toric cavity while being in contact at least locally with said first stiffening element.

[0108] Optionally, the tire comprises a second anchoring member arranged in the toric cavity and extending projecting from the second sidewall and / or bead towards the inside of the toric cavity and / or from the crown towards the inside of the toric cavity while being in contact at least locally with said stiffening structure.

[0109] In embodiments using a second stiffening element, the second anchoring member projects from the second flank and / or bead towards the interior of the toric cavity and / or from the top towards the interior of the toric cavity while being in contact at least locally with said second stiffening element.

[0110] Preferably, said first anchoring member is made in one piece with at least the first flank and / or bead and / or with the top.

[0111] Preferably, said second anchoring member is made in one piece with at least the second flank and / or bead and / or with the top.

[0112] By material origin, it is meant that the corresponding anchoring member is not subsequently attached to the crosslinking of the tire, for example by bonding subsequent to the crosslinking of the tire. Thus, the corresponding anchoring member is crosslinked simultaneously with the first or second sidewall and / or bead and / or with the crown.

[0113] According to the first design described above, the first inner layer forms at least a part of said first anchoring member. In other words, at least a part of said first member is integral with the first inner layer.

[0114] Optionally, the second inner layer forms at least a portion of said second anchoring member. In other words, at least a portion of said second member is integral with the second inner layer. Such anchoring members make it possible to reinforce an interface between the stiffening structure and the internal surface and make it possible to limit the rupture of the interface resulting from repeated stresses exerted by the stiffening structure on the interface. Thus, the endurance of the stiffening structure is improved. Indeed, such anchoring of the stiffening structure makes it possible to dilute the stresses in the anchoring member and therefore to obtain an anchor whose robustness is improved.

[0115] In the first design described above, the first and / or second inner layer respectively forms the entirety of the first and / or second anchoring member. In other words, the entirety of each first and / or second member is integral with the first and / or second inner layer respectively.

[0116] In other variants of the first design, said first and / or second anchoring member comprises a skin formed respectively by the first and / or second inner layer and a core formed respectively by the first and / or second outer layer. In other words, a skin of each first and / or second member is integrally formed with the first and / or second inner layer respectively and a core of each first and / or second member is integrally formed with the first and / or second outer layer respectively.

[0117] In the second design described above, the first and / or second inner complementary layer respectively forms the entirety of the first and / or second anchoring member. In other words, the entirety of each first and / or second member is integral with the first and / or second inner complementary layer respectively.

[0118] In other variants of the second design, said first and / or second anchoring member comprises a skin formed respectively by the first and / or second inner complementary layer and a core formed respectively by the first and / or second inner layer. In other words, a skin of each first and / or second member is integrally formed respectively with the first and / or second inner complementary layer and a core of each first and / or second member is integrally formed respectively with the first and / or second inner layer.

[0119] In embodiments, the tire comprises a first outer complementary layer forming at least in part the first sidewall and / or bead and / or the crown and arranged radially and / or axially outside the first outer layer, said stiffening structure passing through the first outer layer and penetrating at least in part the first outer complementary layer.

[0120] In embodiments using a first stiffening element, said first stiffening element passes through the first outer layer and at least partially penetrates the first outer complementary layer.

[0121] Optionally, the tire comprises a second outer complementary layer forming at least in part the second sidewall and / or bead and / or the crown and arranged radially and / or axially outside the second outer layer, said stiffening structure passing through the second outer layer and penetrating at least in part the second outer complementary layer.

[0122] In embodiments using a second stiffening element, said second stiffening element passes through the second outer layer and at least partially penetrates the second outer complementary layer.

[0123] Preferably, the first and / or second outer complementary layer is in contact with the first and / or second outer layer respectively.

[0124] In advantageous embodiments, a first complementary modulus ratio between a nominal secant modulus at 10% elongation of the first outer complementary layer and a nominal secant modulus at 10% elongation of the first outer layer is strictly greater than 1.0, preferably greater than or equal to 2.0.

[0125] Optionally, a second complementary modulus ratio between a nominal secant modulus at 10% elongation of the second outer complementary layer and a nominal secant modulus at 10% elongation of the second outer layer is strictly greater than 1.0, preferably greater than or equal to 2.0.

[0126] Thus, the same stiffness gradient mechanism described previously with reference to the first and / or second inner and outer layers is applied to the first and / or second outer and complementary outer layers.

[0127] However, it is quite possible to imagine a ratio of complementary modules between a nominal secant modulus at 10% elongation of the first and / or second outer complementary layer and a nominal secant modulus at 10% elongation of the first and / or second outer layer less than or equal to 1.0. Indeed, since the forces are taken up by the first and / or second outer layer, the first and / or second outer complementary layer does not necessarily need to have high rigidity.

[0128] Advantageously, said stiffening structure or said first stiffening element comprises a portion extending continuously in the toric cavity from the first radially inner anchoring point and the first radially outer anchoring point.

[0129] Advantageously, said stiffening structure or said first stiffening element comprises a radially inner anchoring portion of said stiffening structure or said first stiffening element extending from the first radially inner anchoring point in the first sidewall and / or bead and extending the portion extending continuously in the toric cavity.

[0130] Advantageously, said stiffening structure or said first stiffening element comprises a radially outer anchoring portion of said stiffening structure or said first stiffening element extending from the first radially outer anchoring point in the apex and extending the portion extending continuously in the toric cavity.

[0131] Optionally, said stiffening structure or said second stiffening element comprises a portion extending continuously into the toric cavity from the second radially inner anchoring point and the second radially outer anchoring point.

[0132] Optionally, said stiffening structure or said second stiffening element comprises a radially inner anchoring portion of said stiffening structure or said second stiffening element extending from the second radially inner anchoring point in the second sidewall and / or bead and extending the portion extending continuously in the toric cavity.

[0133] Optionally, said stiffening structure or said second stiffening element comprises a radially outer anchoring portion of said stiffening structure or said second stiffening element extending from the second radially outer anchoring point in the apex and extending the portion extending continuously into the toric cavity.

[0134] In embodiments, at least a portion of said stiffening structure or said first stiffening element and / or said second stiffening element is coated with at least one layer of a polymeric composition, preferably an adhesive composition.

[0135] Such a layer of polymeric composition makes it possible to limit the propagation of air and any corrosive agents along the stiffening structure or the stiffening element and therefore in the structure of the tire. The composition is said to be polymeric because it is based on a polymeric composition, this polymeric composition being able to comprise one or more polymers, for example chosen from thermoplastic polymers, thermosetting and / or crosslinkable polymers, elastomers, thermoplastic elastomers, but also fillers and other components usually used in the field of tire compositions.

[0136] In embodiments, the adhesive composition comprises a resin selected from aldehyde / phenol resins, polyepoxide resins, polyisocyanate resins, aromatic polyepoxy-phenolic resins and polyfunctional resins as well as mixtures of these resins. The adhesive composition makes it possible, in addition to limiting the spread of air and possible corrosive agents, to improve the anchoring of the stiffening elements in the structure of the tire.

[0137] In embodiments, said portion extending continuously into the toric cavity of said stiffening structure or of the or each first stiffening element and / or of the or each second stiffening element may be coated at least in part with the polymeric composition.

[0138] The polymer composition here limits the spread of air and any corrosive agents.

[0139] In embodiments, said radially inner anchoring portion of said stiffening structure or of the or each first stiffening element and / or of the or each second stiffening element may be coated at least in part with the polymeric composition.

[0140] The polymeric composition here makes it possible to improve the anchoring of the stiffening structure in the first sidewall and / or bead and / or second sidewall and / or bead.

[0141] In embodiments, said radially outer anchoring portion of said stiffening structure or of the or each first stiffening element and / or of the or each second stiffening element may be coated at least in part with the polymeric composition.

[0142] The polymer composition here makes it possible to improve the anchoring of the stiffening elements in the crown.

[0143] Advantageously, said first radially inner anchoring point of said first stiffening element and said first radially outer anchoring point of said first stiffening element are arranged on the same side of the median plane of the tire.

[0144] Optionally, said second radially inner anchoring point of said second stiffening element and said second radially outer anchoring point of said second stiffening element are arranged on the same other side of the median plane of the tire.

[0145] Thus, the portions extending on the one hand, between a radially inner anchoring point and a radially outer anchoring point located on the same side of the median plane and on the other hand, between a radially inner anchoring point and a radially outer anchoring point located on the other side of the median plane, do not cross, which makes it possible to limit the axial buckling of the tread, that is to say the axial compression of the tread, in particular under conditions of high lateral stresses. Thus, on the one hand, a regular contact area is maintained, and on the other hand, the risk of deterioration of the crown reinforcement of the tire is reduced, in particular by avoiding the compression of the various constituent elements of the crown reinforcement, for example the textile and metal wire reinforcement elements of the crown reinforcement.

[0146] Preferably, the stiffening structure comprises a plurality of first stiffening elements distributed circumferentially in the toric cavity.

[0147] Optionally, the stiffening structure comprises a plurality of second stiffening elements distributed circumferentially in the toric cavity.

[0148] In a first configuration of the stiffening elements, each first stiffening element forms a first continuous stiffening element which winds at least from the first sidewall and / or bead via the crown. Also preferably, each second stiffening element forms a second continuous stiffening element which winds at least from the second sidewall and / or bead via the crown. Thus, the manufacture of the tire is facilitated and the robustness of the stiffening structure is improved by removing ends of said stiffening element to be anchored in each sidewall and / or bead and / or in the crown. In this first configuration, it is thus possible to have a continuous stiffening element extending over the entire circumference of the tire.The said stiffening element of the stiffening structure being continuous, the transmission of forces between each sidewall and / or bead is improved, the transmission of forces being thus distributed over the tire. Thus, the stiffening structure performs its function over the entire circumference of the tire.

[0149] According to a first variant of the first configuration of the stiffening elements, said first and second stiffening elements form a continuous stiffening element which extends continuously from the first flank and / or bead towards the second flank and / or bead via the top so as to snake from the first flank and / or bead to the second flank and / or bead.

[0150] According to a second variant of the first configuration of the stiffening elements, each first stiffening element forms a continuous stiffening element which winds between the first sidewall and / or bead and the crown. Still in this second variant, each second stiffening element forms a continuous stiffening element which winds between the second sidewall and / or bead and the crown.

[0151] In a second configuration of the stiffening elements, it may be envisaged that each first stiffening element extends from the first sidewall and / or bead to the top and has one end in the first sidewall and / or bead. Similarly, it may be envisaged that each second stiffening element extends from the second sidewall and / or bead to the top and has one end in the second sidewall and / or bead.

[0152] In a first variant of this second configuration, it may be envisaged that each first stiffening element extends from the first sidewall and / or bead to the top and has one end in the top. Similarly, it may be envisaged that each second stiffening element extends from the second sidewall and / or bead to the top and has one end in the top.

[0153] In a second variant of this second configuration, each first stiffening element is respectively each second stiffening element and extends from the first sidewall and / or bead to the second sidewall and / or bead via the top and has an end in each first and second sidewall and / or bead.

[0154] Each stiffening element according to one of the designs or configurations previously defined can be characterized geometrically, in particular by its mean section Sm, this characteristic not necessarily being identical for all the stiffening elements. The mean section Sm is the average of the sections obtained by cutting the stiffening element by all the cylindrical surfaces, coaxial with the tire and radially included in the internal toric cavity. In the most frequent case of a constant section, the mean section Sm is the constant section of the stiffening element. The mean section Sm includes a largest characteristic dimension Dmax and a smallest characteristic dimension Dmin, the ratio of which R= Dmax / Dmin is called the aspect ratio.As examples, a stiffening element having a circular mean section Sm, having a diameter equal to d, has a shape ratio R= l, a stiffening element having a rectangular mean section Sm, having a length L and a width 1, has a shape ratio R=L / 1, and a stiffening element having an elliptical mean section Sm, having a major axis D and a minor axis d, has a shape ratio R=D / d.

[0155] A first type of preferred stiffening element, with a shape ratio R at most equal to 3, is said to be one-dimensional. In other words, a stiffening element is considered one-dimensional when the largest characteristic dimension Dmax of its mean section Sm is at most equal to 3 times the smallest characteristic dimension Dmin of its mean section Sm. A one-dimensional stiffening element has a wire-like mechanical behavior, that is to say that it can only be subjected to extension or compression forces along its mean line. This is the reason why a one-dimensional stiffening element is usually called a wire-like stiffening element.Among the components commonly used in the field of tires, textile wire elements, consisting of an assembly of elementary textile monofilaments, or metal cables, consisting of an assembly of elementary metal monofilaments, can be considered as one-dimensional stiffening elements, because their average section Sm being substantially circular, the aspect ratio R is equal to 1, therefore less than 3.

[0156] A second type of stiffening element, with an aspect ratio R at least equal to 3, is said to be two-dimensional. In other words, a stiffening element is considered two-dimensional when the largest characteristic dimension Dmax of its mean section Sm is at least equal to 3 times the smallest characteristic dimension Dmin of its mean section Sm. A two-dimensional stiffening element has membrane-type mechanical behavior, i.e. it can only be subjected to extension or compression forces in its thickness defined by the smallest characteristic dimension Dmin of its mean section Sm. According to a first variant, a stiffening element, with an aspect ratio R at least equal to 3 and at most equal to 50, is said to be two-dimensional of the strip type. According to a second variant, a stiffening element, with an aspect ratio R at least equal to 50, is said to be two-dimensional of the film type.

[0157] The materials that can be used for each stiffening element are as described in W02022 / 200717.

[0158] In a very advantageous embodiment, the or each first and / or second stiffening element is respectively a first and / or second wire stiffening element, preferably a first and / or second textile wire stiffening element. Preferably, the wire stiffening elements are identical, that is to say they have identical geometric characteristics and constituent materials.

[0159] These stiffening wire elements are usually called stays. The advantage of using stiffening wire elements is to have a stiffening structure with low mass and low hysteresis. The use of identical stiffening wire elements allows for a homogeneous distribution of forces between the stiffening elements.

[0160] By textile is meant that each wire stiffening element is non-metallic, for example made of a material chosen from a polyester, a polyamide, a polyketone, a polyvinyl alcohol, a cellulose, a mineral fiber, a natural fiber, an elastomeric material or a mixture of these materials. Among the polyesters, mention will be made, for example, of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PBN (polybutylene naphthalate), PPT (polypropylene terephthalate), PPN (polypropylene naphthalate). Among the polyamides, mention will be made of aliphatic polyamides such as polyamides 4-6, 6, 6-6 (nylon), 11 or 12 and aromatic polyamides such as aramid. Preferably, the material is a polyester or an aliphatic polyamide.

[0161] Advantageously, in a variant making it possible to manufacture the tire by implementing a relatively simple method, each wire stiffening element extends in the toric cavity in a main direction forming, with the circumferential direction of the tire, an angle ranging, in absolute value, from 85° to 90°. In another variant making it possible to manufacture the tire by implementing a more complex method but making it possible to increase the circumferential stiffness, each wire stiffening element extends in the toric cavity in a main direction forming, with the circumferential direction of the tire, an angle ranging, in absolute value, from 45° to 85° as is explained in particular in WO2020 / 128225.

[0162] Preferably, the stiffening structure or said first stiffening element extending from the first flank and / or bead to the top or said radially inner anchoring portion of said first stiffening element is anchored in the first flank and / or bead by being anchored in or around a first radially inner reinforcing structure of the stiffening structure arranged in the first flank and / or bead. Also preferably, the stiffening structure or said first stiffening element extending from the first flank and / or bead to the top or said radially outer anchoring portion of said first stiffening element is anchored in the top by being anchored in or around one or more radially outer reinforcing structures of the stiffening structure arranged in the top.

[0163] Advantageously, the first radially inner reinforcing structure is arranged in the first outer layer or the outer complementary layer.

[0164] Advantageously, the first radially outer reinforcing structure is arranged in the first inner layer. Indeed, taking into account the inclination of the stiffening structure, the forces exerted at the top by the stiffening structure on the anchor include high shear forces and low tensile forces, unlike the forces exerted in the sidewall and / or the bead, which include low shear forces and high tensile forces. It is thus possible to anchor the stiffening structure in the least rigid layer, which has sufficient rigidity to absorb the low tensile forces.

[0165] Alternatively, the first radially outer reinforcing structure is arranged in the first outer layer or the first outer complementary layer.

[0166] Alternatively, the stiffening structure or said first stiffening element extending from the first sidewall and / or bead to the top or said radially inner anchoring portion of said first stiffening element is anchored in the first sidewall and / or bead by being anchored in an elastomeric mass of said first sidewall and / or bead. Also as a variant, the stiffening structure or said first stiffening element extending from the first sidewall and / or bead to the top or said radially outer anchoring portion of said first stiffening element is anchored in the top by being anchored in an elastomeric mass of said top.

[0167] Optionally, the stiffening structure or said second stiffening element extending from the second flank and / or bead to the top or said radially inner anchoring portion of said second stiffening element is anchored in the second flank and / or bead by being anchored in or around a second radially inner reinforcing structure of the stiffening structure arranged in the second flank and / or bead. Also optionally, the stiffening structure or said second stiffening element extending from the second flank and / or bead to the top or said radially outer anchoring portion of said second stiffening element is anchored in the top by being anchored in or around one or more radially outer reinforcing structures of the stiffening structure arranged in the top.

[0168] Advantageously, the second radially inner reinforcing structure is arranged in the second outer layer or the outer complementary layer.

[0169] Advantageously, the second radially outer reinforcing structure is arranged in the second inner layer for reasons similar to those described for the first radially outer reinforcing structure.

[0170] Alternatively, the second radially outer reinforcing structure is arranged in the second outer layer or the second outer complementary layer. Alternatively, the stiffening structure or said second stiffening element extending from the second sidewall and / or bead to the top or said radially inner anchoring portion of said second stiffening element is anchored in the second sidewall and / or bead by being anchored in an elastomeric mass of said second sidewall and / or bead. Also alternatively, the stiffening structure or said second stiffening element extending from the second sidewall and / or bead to the top or said radially outer anchoring portion of said second stiffening element is anchored in the top by being anchored in an elastomeric mass of said top.

[0171] Of course, the tire may comprise both the first and second radially inner reinforcing structures and the radially outer reinforcing structure(s) or only the first and second radially inner reinforcing structures or only the radially outer reinforcing structure(s).

[0172] Each radially inner or outer reinforcing structure is respectively arranged in the corresponding flank and / or bead or in the crown, that is to say arranged radially inside the internal surface and embedded in the mass of materials constituting the corresponding flank and / or bead or the crown. The stiffening structure passes through the internal surface to be anchored in or around the corresponding radially inner reinforcing structure and / or through the internal surface to be anchored in or around the or one of the radially outer reinforcing structure(s).

[0173] As previously indicated, the stiffening structure may be anchored in or around at least one radially inner and / or outer reinforcing structure.

[0174] Thus, in a first variant, the stiffening structure can be anchored in the very structure of said reinforcing structure, that is to say that the stiffening structure penetrates at least partly into said reinforcing structure, or even crosses it completely so that said reinforcing structure forms a mechanical anchoring of the stiffening structure.

[0175] In particular, in the case where said reinforcing structure is an assembly of several wire elements, the stiffening structure is "anchored in the structure" means, for example, that the stiffening structure wraps around certain wire elements of said reinforcing structure so as to pass through it.

[0176] In a second variant, the stiffening structure can be anchored around the very structure of said reinforcing structure, that is to say that the stiffening structure bears on said reinforcing structure so that said reinforcing structure absorbs part of the forces exerted on the stiffening structure and anchors the stiffening structure in the sidewall and / or the bead or the crown.

[0177] In particular, in the case where said reinforcing structure is an assembly of several wire elements, the stiffening structure is "anchored around the structure" means, for example, that the stiffening structure wraps around the peripheral wire elements of said reinforcing structure without passing through it.

[0178] In the embodiments comprising a first radially internal reinforcement structure arranged in the first sidewall and / or bead, the latter preferably comprises at least one first radially internal circumferential reinforcement element allowing the anchoring of the stiffening structure.

[0179] In the embodiments comprising a second radially internal reinforcing structure arranged in the second sidewall and / or bead, the latter preferably comprises at least one second radially internal circumferential reinforcing element allowing the anchoring of the stiffening structure.

[0180] In a preferred variant, each first and second bead respectively comprises a first and second radially inner circumferential reinforcing element intended to allow the tire to be attached to a tire mounting support, said first radially inner circumferential reinforcing element or each first and second radially inner circumferential reinforcing element being arranged radially outside each first and second circumferential reinforcing element intended to allow the tire to be attached to a tire mounting support.

[0181] Thus, the propagation of noise generated by the stiffening structure from the stiffening structure to the vehicle through the tire mounting support is reduced. In fact, the noise generated by the stiffening structure is damped by the tire structure separating the radially inner circumferential reinforcing element considered from the radially inner circumferential reinforcing element intended to allow the tire to be attached to a tire mounting support located on the same side of the median plane of the tire.

[0182] This damping is the result of the fact that the radially inner circumferential reinforcing element considered is mechanically decoupled from said radially inner circumferential reinforcing element intended to allow the tire to be attached to a tire mounting support located on the same side of the median plane of the tire.

[0183] Alternatively, said first radially inner circumferential reinforcing element or each first and second radially inner circumferential reinforcing element is intended to allow the tire to be attached to a tire mounting support.

[0184] In one embodiment, said first radially inner circumferential reinforcing element or each first and second radially inner circumferential reinforcing element is a wire reinforcing element extending in a main direction forming with the circumferential direction of the tire an angle less than or equal to 10°, preferably less than or equal to 5° and more preferably substantially zero.

[0185] In the embodiments comprising at least one radially outer reinforcing structure arranged in the crown, the latter preferably comprises at least one radially outer circumferential reinforcing element.

[0186] In one embodiment, said radially outer circumferential reinforcing element of the or each radially outer reinforcing structure is a wire reinforcing element extending in a main direction forming with the circumferential direction of the tire an angle less than or equal to 10°, preferably less than or equal to 5° and more preferably substantially zero.

[0187] In some embodiments, the tire comprises first and second radially outer reinforcing structures. In these embodiments, preferably, each first and second radially outer reinforcing structure respectively comprises a first and second radially outer circumferential reinforcing element, the first radially outer circumferential reinforcing element being arranged axially spaced from said second radially outer circumferential reinforcing element.

[0188] This makes it possible to reduce the mass of the reinforcement structure allowing the anchoring of the stiffening structure in the crown and to limit the over-frettage of the crown, thus making it possible to maintain a regular contact area.

[0189] Preferably, the first radially outer circumferential reinforcing element and the second radially outer circumferential reinforcing element are arranged on either side of the median plane of the tire.

[0190] This improves the axial distribution of the forces exerted by the stiffening structure on the top.

[0191] Each radially inner circumferential reinforcing element and each radially outer circumferential reinforcing element may be wound in different ways such as described in particular in W02022 / 200717.

[0192] Of course, the tire may comprise several of said first and / or second radially inner and / or outer reinforcement structures.

[0193] Brief description of the drawings The present invention will be better understood upon studying the detailed description of embodiments, taken as non-limiting examples and illustrated by the appended drawings in which:

[0194] - figure 1 is a view of a tire in a meridian section plane parallel to the axis of rotation according to a first exemplary embodiment of the invention;

[0195] - figure 2 is a view similar to that of figure 1 of a tire according to a second exemplary embodiment of the invention;

[0196] - Figure 3 is a schematic perspective view of the interior of the tire of Figure 2; and

[0197] - figure 4 is a view similar to that of figure 1 of a tire according to a third exemplary embodiment of the invention.

[0198] Detailed description

[0199] In the figures relating to the tire, a reference X, Y, Z is shown corresponding to the usual axial (Y), radial (Z) and circumferential (X) directions of a tire.

[0200] The figures represent a tire 10 having a substantially toric shape around an axis of revolution substantially parallel to the axial direction Y. The tire 10 is intended for a passenger vehicle and has a dimension of 275 / 35ZR19. In the various figures, the tire 10 is shown in new condition, that is to say not having yet been driven.

[0201] The tire 10 comprises a crown 12 comprising a tread 14 intended to come into contact with a ground when rolling and a crown reinforcement 16 extending in the crown 12 in the circumferential direction X.

[0202] The tire 10 further comprises a crown reinforcement identical to that described in WO2022 / 200717 comprising a working reinforcement 20 comprising working layers 24, 26 as well as a hoop reinforcement 22 comprising a hoop layer 28.

[0203] The tire 10 comprises first and second sidewalls 30A, 30B extending the crown 12 radially inward. The second sidewall 30B is opposite the first sidewall 30A relative to the median plane M. The tire 10 further comprises first and second beads 32A, 32B extending each first and second sidewall 30A, 30B radially inward respectively. The second bead 32B is opposite the first bead 32A relative to the median plane M. Each first and second sidewall 30A, 30B connects each first and second bead 32A, 32B respectively to the crown 12.

[0204] The tire 10 comprises first and second outer layers 33A, 33B forming in part each first and second sidewall 30A, 30B and each first and second bead 32A, 32B. Each first and second outer layer 33A, 33B comprises an elastomeric composition not having a sealing function. The elastomeric composition of each first and second outer layer 33A, 33B comprises less than 50 phr of butyl rubber, preferably less than 10 phr of butyl rubber and is more preferably here substantially free of butyl rubber. In addition, the elastomeric composition of each first and second outer layer 33A, 33B comprises at least 50 phr of a diene elastomer, for example natural rubber. A person skilled in the art will easily know how to formulate and manufacture such compositions which are identical here.

[0205] An internal surface 34, intended to be in contact with the inflation gas of the tire, delimits a toric cavity 36 for inflation of the tire 10.

[0206] The tire 10 comprises first and second inner layers 37A, 37B forming in part each first and second sidewall 30A, 30B, each first and second bead 32A, 32B and the crown 12. Each first and second outer layer 33A, 33B is arranged radially and axially outside of respectively each first and second inner layer 37A, 37B while being in contact with each first and second inner layer 37A, 37B. Each first and second inner layer 37A, 37B forms at least in part the inner surface 34 and here the entirety of each first and second inner layer 37A, 37B forms at least a part of the inner surface 34. The tire 10 comprises first and second radially inner reinforcing structures 38A, 38B respectively arranged in each first and second bead 32A, 32B.

[0207] Each first and second radially inner reinforcing structure 38A, 38B respectively comprises first and second radially inner circumferential reinforcing elements 40A, 40B, respectively arranged in each first and second bead 32A, 32B, here comprising first and second wire reinforcing elements as described in WO2022 / 200717. More specifically, the first and second radially inner circumferential reinforcing elements 40A, 40B are arranged in each first and second outer layer 33A, 33B.

[0208] Each first and second bead 32A, 32B respectively comprises a first and second radially inner circumferential reinforcing element 42A, 42B, here a bead wire, intended to allow the tire 10 to be attached to a mounting support for the tire 10, for example a rim.

[0209] Each first and second radially inner circumferential reinforcing element 40A, 40B is respectively arranged radially outside each first and second radially inner circumferential reinforcing element 42A, 42B intended to allow the attachment of the tire 10 to a mounting support for the tire 10.

[0210] The tire 10 further comprises first and second radially outer reinforcing structures 44A, 44B arranged in the crown 12 and each provided respectively with a first and second radially outer circumferential reinforcing element 46A, 46B arranged axially on either side of the median plane M of the tire 10 and here substantially symmetrically with respect to the median plane M of the tire 10. Each first and second radially outer circumferential reinforcing element 46A, 46B is as described in WO2022 / 2007 17. More specifically, the first and second radially outer circumferential reinforcing elements 46A, 46B are arranged respectively in each first and second inner layer 37A, 37B.The tire 10 comprises a carcass reinforcement 48 anchored in each first and second bead 32A, 32B, in this case wound around each first and second radially inner circumferential reinforcing element 42A, 42B intended to allow the tire 10 to be attached to a mounting support for the tire 10. The carcass reinforcement 48 extends in each first and second bead 32A, 32B and in each first and second sidewall 30A, 30B such that each first and second radially inner circumferential reinforcing element 40A, 40B is arranged radially inside the carcass reinforcement 48. The carcass reinforcement 48 also extends in the crown 12 radially inside the crown reinforcement 16. The crown reinforcement 16 is arranged radially between the tread 14 and the carcass reinforcement 48.The carcass reinforcement 48 comprises at least one carcass layer 50 and here comprises a single carcass layer 50.

[0211] Each first and second inner layer 37A, 37B and each first and second outer layer 33A, 33B is arranged radially and / or axially within the single carcass layer 50.

[0212] The different crown layers 24, 26, 28 and carcass 50 are identical to those described in W02022 / 200717.

[0213] The tire 10 comprises a stiffening structure 52 extending in the toric cavity 36 from the first bead 32A to the crown 12 and which is anchored in the first bead 32A by extending in the first bead 32A and here by being anchored around the first radially inner reinforcement structure 38A. The stiffening structure 52 extends in the toric cavity 36 from the second bead 32B to the crown 12 and is anchored in the second bead 32B by extending in the second bead 32B and here by being anchored around the second radially inner reinforcement structure 38B. The stiffening structure 52 extends in the toric cavity 36 from the first bead 32A and from the second bead 32B to the crown 12 and is anchored in the crown 12 by extending into the crown 12 and here by being anchored around the radially outer reinforcing structures 44A, 44B.

[0214] The stiffening structure 52 comprises a plurality of stiffening elements 54 comprising a plurality of first stiffening elements 54A extending continuously in the toric cavity 36 and a plurality of second stiffening elements 54B extending continuously in the toric cavity 36. The first and second stiffening elements 54A, 54B are distributed circumferentially in the toric cavity 36.

[0215] Each stiffening element 54 is a textile wire stiffening element comprising an assembly of three multifilament strands of aliphatic polyamide, for example nylon, these three multifilament strands being individually helical at 190 turns per meter in one direction and then helical together at 190 turns per meter in the opposite direction. Each of these multifilament strands has a count equal to 188 tex.

[0216] Each first stiffening element 54A extends continuously from the first flank 30A and / or the first bead 32A to the top 12 and here from the first bead 32A to the top 12. Each second stiffening element 54B extends continuously from the second flank 30A and / or the second bead 32A to the top 12 and here from the second bead 32A to the top 12.

[0217] In order to ensure optimal anchoring of the first and second stiffening elements 54A, 54B, each first and second radially inner reinforcing structure 38A, 38B, in particular each first and second radially inner circumferential reinforcing element 40A, 40B, has relatively high extension and bending rigidities. Furthermore, still with the aim of optimizing the anchoring of each stiffening element 54, the nominal secant modulus at 10% elongation of each first and second outer layer 33A, 33B is greater than or equal to 5 MPa and less than or equal to 60 MPa, preferably less than or equal to 20 MPa and here equal to 12 MPa.In order to ensure optimal anchoring of the first and second stiffening elements 54A, 54B, each first and second radially outer reinforcing structure 44A, 44B, in particular each first and second radially outer circumferential reinforcing element 46A, 46B, has a relatively high extension rigidity and a relatively low bending rigidity in order to limit over-frettage of the crown 12 and not risk damaging the flattening of the tread 14. Furthermore, still with the aim of optimizing the anchoring of each stiffening element 54, the nominal secant modulus at 10% elongation of each first and second inner layer 37A, 37B is greater than or equal to 1 MPa and less than or equal to 8 MPa, preferably less than or equal to 5 MPa, and here equal to 3 MPa.

[0218] Thus, first and second modulus ratios can be defined calculated as the ratio between the nominal secant modulus at 10% elongation of each first and second outer layer 33A, 33B and the nominal secant modulus at 10% elongation respectively of each first and second inner layer 37A, 37B. Each first and second modulus ratio is strictly greater than 1.0, preferably greater than or equal to 2.0, more preferably greater than or equal to 3.0. In addition, each first and second modulus ratio is less than or equal to 20.0, preferably less than or equal to 15.0, more preferably less than or equal to 10.0 and even more preferably less than or equal to 7.0 and here equal to 4.0. Such first and second modulus ratios make it possible to improve the endurance of the stiffening structure 52.

[0219] Each first stiffening element 54A is anchored, in the first bead 32A, around the first radially inner reinforcing structure 38A, in particular around the first radially inner circumferential reinforcing element 40A. Each second stiffening element 54B is anchored in the second bead 32B, around the second radially inner reinforcing structure 38B, in particular around the second radially inner circumferential reinforcing element 40B. Here, each first and second stiffening element 54A, 54B is wound at least in part respectively around each first and second radially inner circumferential reinforcing element 40A, 40B.

[0220] Each first and second stiffening element 54A, 54B is also anchored, in the apex 12, respectively around each first and second radially outer reinforcing structure 44A, 44B, in particular around each first and second radially outer circumferential reinforcing element 46A, 46B. Here, each first and second stiffening element 54A, 54B is wound at least in part respectively around each first and second radially outer circumferential reinforcing element 46A, 46B.

[0221] Each first stiffening element 54A passes through the inner surface 34 at a first radially inner anchoring point 56A arranged in the first bead 32A to be anchored around the first radially inner reinforcing structure 38A and at a first radially outer anchoring point 58A arranged in the crown 12 to be anchored around the first radially outer reinforcing structure 44A. Thus, each first stiffening element 54A is anchored in the first bead 32A by extending into the first bead 32A from the first radially inner anchoring point 56A. Each first stiffening element 54A is anchored in the crown 12 by extending into the crown 12 from the first radially outer anchoring point 58A.

[0222] Each second stiffening element 54B passes through the inner surface 34 at a second radially inner anchoring point 56B arranged in the second bead 32B to be anchored around the second radially inner reinforcing structure 38B and at a second radially outer anchoring point 58B arranged in the crown 12 to be anchored around the second radially outer reinforcing structure 44B. Thus, each second stiffening element 54B is anchored in the second bead 32B by extending into the second bead 32B from the second radially inner anchoring point 56B. Each second stiffening element 54B is anchored in the crown 12 by extending into the crown 12 from the second radially outer anchoring point 58B.Each first stiffening element 54A comprises a radially inner anchoring portion 541, a portion 543, and a radially outer anchoring portion 545, the portion 543 being extended on the one hand by the radially inner anchoring portion 541 and on the other hand by the radially outer anchoring portion 545.

[0223] Each second stiffening element 54B comprises a radially inner anchoring portion 542, a portion 544, and a radially outer anchoring portion 546, the portion 544 being extended on the one hand by the radially inner anchoring portion 542 and on the other hand by the radially outer anchoring portion 546.

[0224] The portion 543 of each first stiffening element 54A extends continuously in the toric cavity 36 from the first radially inner anchoring point 56A to the first radially outer anchoring point 58A.

[0225] The portion 544 of each second stiffening element 54B extends into the toric cavity 36 from the second radially inner anchoring point 56B to the second radially outer anchoring point 58B.

[0226] The radially inner anchoring portion 541 of each first stiffening element 54A extends from the first radially inner anchoring point 56A in the first bead 32A to be anchored around the first radially inner reinforcing structure 38A.

[0227] The radially outer anchoring portion 545 of each first stiffening element 54A extends from the first radially outer anchoring point 58A in the apex 12 to be anchored around the first radially outer reinforcing structure 44A.

[0228] The radially inner anchoring portion 542 of each second stiffening element 54B extends from the second radially inner anchoring point 56B in the second bead 32B to be anchored around the second radially inner reinforcing structure 38B. The radially outer anchoring portion 546 of each second stiffening element 54B extends from the second radially outer anchoring point 58B in the crown 12 to be anchored around the second radially outer reinforcing structure 44B.

[0229] The stiffening structure 52, here each first stiffening element 54A, and more precisely, each radially inner 541 and outer 545 anchoring portion penetrates the first inner layer 37A respectively at the first radially inner anchoring point 56A arranged in the first bead 32A and at the first radially outer point 58A arranged in the crown 12. The stiffening structure 52, here each first stiffening element 54A, and more precisely, each radially inner anchoring portion 541 passes through the first inner layer 37A and partially penetrates the first outer layer 33A from the first radially inner anchoring point 56A. The first inner layer 37A is in contact at least locally with the stiffening structure 52, and here in contact with each first stiffening element 54A, at the first radially inner 56A and outer 58A anchoring point.

[0230] The stiffening structure 52, here each second stiffening element 54B, and more precisely, the radially inner 542 and outer 546 anchoring portion penetrates the second inner layer 37B respectively at the second radially inner anchoring point 56B arranged in the second bead 32B and at the second radially outer point 58B arranged in the crown 12. The stiffening structure 52, here each second stiffening element 54B, and more precisely, the radially inner anchoring portion 542 passes through the second inner layer 37B and partially penetrates the second outer layer 33B from the second radially inner anchoring point 56B. The second inner layer 37B is in contact at least locally with the stiffening structure 52, and here in contact with each second stiffening element 54B, at the second radially inner 56B and outer 58B anchoring point.Each first stiffening element 54A forms a first continuous stiffening element which winds from the first bead 32A passing through the apex 12 and each second stiffening element 54B forms a second continuous stiffening element which winds at least from the second bead 32B passing through the apex 12. More precisely, the first and second stiffening elements 54A, 54B form a continuous stiffening element which extends continuously from the first bead 32A to the second bead 32B passing through the apex 12 so as to wind from the first bead 32A to the second bead 32B.

[0231] As illustrated in FIG. 1, the first radially outer anchoring point 58A is arranged axially on the same side as the first radially inner anchoring point 56A and the first radially inner reinforcing structure 38A relative to the median plane M. The second radially outer anchoring point 58B is arranged axially on the same other side as the second radially inner anchoring point 56B and the second radially inner reinforcing structure 38B relative to the median plane M. Each first and second radially inner anchoring point 56A, 56B and outer 58A, 56B is arranged so that the portions 543, 544 do not intersect in the toric cavity 36.

[0232] With reference to FIG. 1, the thickness of each first and second inner layer 37A, 37B is greater than or equal to 0.1 mm and less than or equal to 5 mm, preferably greater than or equal to 0.1 mm and less than or equal to 2 mm and here equal to 0.5 mm at each first and second radially inner anchoring point 56A, 56B.

[0233] The thickness of each first and second outer layer 33A, 33B is greater than or equal to 2 mm and less than or equal to 20 mm and here equal to 4 mm at each first and second radially inner anchoring point 56A, 56B.

[0234] Each first and second outer layer 33A, 33B and inner layer 37A, 37B comprises an elastomeric composition not having a sealing function. The elastomeric composition of each first and second outer layer 33A, 33B and inner layer 37A, 37B comprises less than 50 phr of butyl rubber, preferably less than 10 phr of butyl rubber and is more preferably here substantially free of butyl rubber. In addition, the elastomeric composition of each first and second outer layer 33A, 33B and inner layer 37A, 37B comprises at least 50 phr of a diene elastomer, for example natural rubber. The compositions of each first and second outer layer 33A, 33B are identical. The compositions of each first and second inner layer 37A, 37B are identical. A person skilled in the art will know without difficulty how to formulate and manufacture such compositions.

[0235] Alternatively, each first and second inner layer 37A, 37B could comprise a sealing composition comprising one or more butyl rubbers, for example such as those described in WO2016 / 001226A1. Such a composition comprises at least 50 phr of the one or more butyl rubbers.

[0236] Each first and second stiffening element 54A, 54B, in particular each portion 541, 543, 545, 542, 544, 546 is coated with an adhesive composition, here an adhesive composition comprising an aldehyde / phenol resin based on resorcinol, formaldehyde and an elastomer latex as described in WO2013017422. Alternatively, any other adhesive composition described in WO2013017422 may be used.

[0237] The second embodiment illustrated in Figures 2 and 3, in which the elements identical to those of the preceding figures bear the same references, differs from the first example illustrated in Figure 1 in that the tire 10 also comprises first radially inner anchoring members 60A arranged in the toric cavity 36 and extending in projection from the first bead 32A towards the interior of the toric cavity 12 while being in contact at least locally with the stiffening structure 52, here with each first stiffening element 54A. The tire 10 also comprises first radially outer anchoring members 62A arranged in the toric cavity 36 and extending in projection from the crown 12 towards the interior of the toric cavity 36 while being in contact at least locally with the stiffening structure 52, here with each first stiffening element 54A.

[0238] The tire 10 also comprises second radially inner anchoring members 60B arranged in the toric cavity 36 and extending in projection from the second bead 32B towards the interior of the toric cavity 36 while being in contact at least locally with the stiffening structure 52, here with each second stiffening element 54B. The tire 10 also comprises second radially outer anchoring members 62B arranged in the toric cavity 36 and extending in projection from the crown 12 towards the interior of the toric cavity 36 while being in contact at least locally with the stiffening structure 52, here with each second stiffening element 54B.

[0239] Each first and second radially inner anchoring member 60A, 60B is integral with each first and second bead 32A, 32B respectively. Each first and second radially outer anchoring member 62A, 62B is integral with the apex 12. Furthermore, each first and second inner layer 37A, 37B at least partially forms each first and second radially inner anchoring member 60A, 60B and outer 62A, 62B. In this case, each first and second radially inner anchoring member 60A, 60B comprises a skin formed respectively by each first and second inner layer 37A, 37B and a core formed respectively by each first and second outer layer 33A, 33B, this core-skin structure being due to the creep of the composition of each first and second outer layer 33A, 33B during the molding and vulcanization of the tire 10.Each first and second inner layer 37A, 37B forms the entirety of each first and second radially outer anchoring member 62A, 62B respectively.

[0240] Alternatively, it may be imagined that each first and second inner layer 37A, 37B forms the entirety of each first and second radially inner anchoring member 60A, 60B. Each first and second radially inner anchoring member 60A, 60B and outer anchoring member 62A, 62B has the shape of a stud, in particular a stud whose height is greater than 1 mm, in particular greater than 2 mm, more particularly greater than 3 mm.

[0241] The tire 10 further comprises first and second inner complementary layers 18A, 18B forming in part each first and second sidewall 30A, 30B, each first and second bead 32A, 32B and the crown 12. Each first and second inner complementary layer 18A, 18B is arranged radially and / or axially inside respectively each first and second inner layer 37A, 37B and in contact respectively with each first and second inner layer 37A, 37B. The first inner complementary layer 18A is arranged at a distance from the first radially inner and outer anchoring points 56A, 58A and the second inner complementary layer 18B is arranged at a distance from the second radially inner and outer anchoring points 56B, 58B. Each first and second inner complementary layer 18A, 18B forms in part the inner surface 34.Each first and second inner complementary layer 18A, 18B is a sealing layer to at least one inflation gas and comprises a sealing composition comprising one or more butyl rubbers, for example such as those described in WO2016 / 001226A1. Such a composition comprises at least 50 pce of the butyl rubber(s).

[0242] The third embodiment illustrated in Figure 4 in which the elements identical to those of the preceding figures bear the same references, differs from the first example illustrated in Figure 1 in that the tire 10 comprises first and second inner complementary layers 18A, 18B forming the inner surface 34 and in that the stiffening structure 52, here each first and second stiffening element 54A, 54B and more precisely each radially inner portion 541, 542 and outer portion 545, 546 respectively passes through each first and second inner complementary layer 18A, 18B from the first and second radially inner anchoring points 56A, 58A and outer anchoring points 58A, 58B of each first and second inner complementary layer 18A, 18B.

[0243] Thus, each first and second interior complementary layer 18A, 18B is here in contact at least locally with the stiffening structure 52, here respectively with each first and second stiffening element 54A, 54B at the first and second radially interior anchoring point 56A, 56B and exterior 58A, 58B.

[0244] Each first and second interior complementary layer 18A, 18B is such that first and second complementary modulus ratios between a nominal secant modulus at 10% elongation of each first and second interior layer 37A, 37B, here equal to 3 MPa, and a nominal secant modulus at 10% elongation respectively of each first and second interior complementary layer 18A, 18B, here equal for example to 1.5 MPa, is strictly greater than 1.0 and here equal to 2.0.

[0245] Alternatively, we can imagine first and second complementary module ratios less than or equal to 1.0.

[0246] Comparative tests

[0247] A control tire having first and second modulus ratios equal to 1.0, i.e. comprising the same elastomeric composition for both the outer and inner layers, was numerically tested. A tire according to the invention identical to the tire according to the first embodiment example was also numerically tested.

[0248] The addition of a stiffness gradient between the outer layer and the inner layer defining first and second modulus ratios strictly greater than 1.0 made it possible to significantly improve the endurance of the stiffening structure. For example, for first and second modulus ratios equal to 4.0, the numerical tests showed a reduction of more than 40% in the displacement of the stiffening elements in the structure of the tire according to the invention compared to the control tire as well as a reduction of nearly 50% in the stresses exerted by the stiffening elements on the layer that the stiffening elements penetrate first, namely each first and second inner layer of the tire according to the invention, compared to the layer penetrated first by the stiffening elements of the control tire.

Claims

CLAIMS 1. A tire (10) comprising a crown (12), first and second sidewalls (30A, 30B) each extending the crown (12) radially inward, first and second beads (32A, 32B) respectively extending the first and second sidewalls (30A, 30B) radially inward, the tire (10) being provided with an internal surface (34) delimiting a toric cavity (36) for inflating the tire (10), the tire (10) comprising: - a first inner layer (37) forming at least in part the first sidewall (30A) and / or bead (32A) and / or the crown (12), - a first outer layer (33A) forming at least in part the first flank (30A) and / or bead (32A) and / or the crown (12), and arranged radially and / or axially outside the first inner layer (37A) while being in contact with the first inner layer (37A), - a stiffening structure (52) extending continuously in the toric cavity (36) from at least the first flank (30A) and / or bead (32A) to at least the apex (12) and being anchored in the first flank (30A) and / or bead (32A) and / or in the apex (12) by extending in the first flank (30A) and / or bead (32A) and / or the apex (12), said stiffening structure (52) passing through the first inner layer (37A) and penetrating at least partly the first outer layer (33A) in the first flank (30A) and / or bead (32A) and / or the apex (12), characterized in that a first modulus ratio between a nominal secant modulus at 10% elongation of the first outer layer (33A) and a nominal secant modulus at 10% elongation of the first inner layer (37A) is strictly greater than 1.

0.

2. Tire (10) according to the preceding claim, comprising: - a second inner layer (37B) forming at least in part the second sidewall (30B) and / or bead (32B) and / or the crown (12), - a second outer layer (33B) further forming at least in part the second flank (30B) and / or bead (32B) and / or the crown (12), and arranged radially and / or axially outside the second inner layer (37B) while being in contact with the second inner layer (37B), - the stiffening structure (52) extending continuously in the toric cavity (36) from at least the second flank (30B) and / or bead (32B) to at least the crown (12) and being anchored in the second flank (30B) and / or bead (32B) and / or in the crown (12) by extending in the second flank (30B) and / or bead (32B) and / or in the crown (12), said stiffening structure (52) passing through the second inner layer (37B) and penetrating at least in part the second outer layer (33A) in the second flank (30A) and / or bead (32A) and / or the crown (12), a second modulus ratio between a nominal secant modulus at 10% elongation of the second outer layer (33B) and a modulus The nominal secant at 10% elongation of the second inner layer (37B) is strictly greater than 1.

0.

3. Tire (10) according to any one of the preceding claims, in which the first and / or second modulus ratio is greater than or equal to 2.0, preferably greater than or equal to 3.

0.

4. A tire (10) according to any one of the preceding claims, wherein the first modulus ratio is less than 20.0, preferably less than or equal to 15.0, more preferably less than or equal to 10.0 and even more preferably less than or equal to 7.

0.

5. Tire (10) according to any one of the preceding claims, in which the nominal secant modulus at 10% elongation of the first outer layer (33A, 33B) is greater than or equal to 5 MPa.

6. Pneumatically (10) according to any one of the preceding claims, in which the nominal secant modulus at 10% elongation of the first outer layer (33A, 33B) is less than or equal to 60 MPa, preferably less than or equal to 20 MPa.

7. Tire (10) according to any one of the preceding claims, in which the nominal secant modulus at 10% elongation of the first inner layer (37A, 37B) is less than or equal to 8 MPa, preferably less than or equal to 5 MPa.

8. Tire (10) according to any one of claims 1 to 7, wherein the first inner layer (37A) at least partly forms the inner surface (34), said stiffening structure (52) penetrating the first inner layer at a first anchoring point (56A, 58A) radially inner and / or outer of the first inner layer (37A) arranged in the first sidewall (30A) and / or bead (32A) and / or the crown (12).

9. A tire (10) according to claim 8, wherein the entirety of the first inner layer (37A) forms at least a portion of the inner surface.

10. Tire (10) according to claim 8, comprising a first inner complementary layer (18A) forming at least in part the first sidewall (30A) and / or bead (32A) and / or the crown (12) and arranged radially and / or axially inside the first inner layer (37A), the first inner complementary layer (18A) forming at least in part the internal surface (34), the first inner complementary layer (18A) is arranged at a distance from said first anchoring point (56A, 58A) radially inside and / or outside the stiffening structure (52). 1 1. Tire (10) according to the preceding claim, in which the first inner complementary layer (18A) is a sealing layer to at least one inflation gas.

12. Tire (10) according to any one of claims 1 to 7, comprising a first inner complementary layer (39) forming at least in part the first sidewall (30A) and / or bead (32A) and / or the crown (12) and arranged radially and / or axially inside the first inner layer (37A), the first inner complementary layer (39) forming at least in part the internal surface (34), said stiffening structure (52) passing through the first inner complementary layer and penetrating the first layer complementary inner layer to a first anchoring point (56A, 58A) radially inner and / or outer of the first inner complementary layer arranged in the first sidewall (30A) and / or bead (32A) and / or the crown (12).

13. Tire (10) according to any one of the preceding claims, comprising a first anchoring member (60A, 62A) arranged in the toric cavity (36) and extending projecting from the first sidewall (30A) and / or bead (32A) towards the inside of the toric cavity (36) and / or from the crown towards the inside of the toric cavity (36) while being in contact at least locally with said stiffening structure (52), the first inner layer forms at least a part of said first anchoring member.

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