Pneumatic system comprising a durable stiffening structure and a possible interrupted sealing layer

Abstract

The tire (10) comprises a crown (12), first and second sidewalls (30A, 30B), first and second bead ribs (32A, 32B), an inner surface (34) defining a toroidal inflation cavity (36) for the tire (10), a first stiffening element (54A) extending continuously into the toroidal cavity (36) from a radially internal (56A) and / or external (58A) anchor point of said first stiffening element (54A), and a sealing layer (18) against an inflation gas forming part of the inner surface (34) and remaining at a distance from said radially internal and / or external anchor point (56A, 58A). Figure for the abbreviation: Fig 1

Description

Title of the invention: A pneumatic system comprising a durable stiffening structure and an optional interrupted sealing layer technical field

[0001] The present invention relates to a tire, in particular for passenger vehicles.

[0002] By pneumatic tire, we mean a tire designed to form a cavity by cooperating with a mounting support, for example a rim, this cavity being capable of being pressurized to a pressure greater than atmospheric pressure. A pneumatic tire has a substantially toroidal shape of revolution around a principal axis of the tire, this principal axis coinciding with the axis of rotation of the tire. Previous techniques

[0003] A tire for use on a passenger vehicle, described in WO2020 / 128225, is known from the prior art. The tire described comprises a crown extended radially inward on each side of the tire's median plane by first and second sidewalls, and then by first and second bead sections designed to contact a mounting support, for example, a rim. Each first and second bead section includes a circumferential reinforcing element designed to secure the tire to the mounting support.

[0004] The tire includes an internal surface delimiting a toroidal cavity for inflating the tire once the latter is mounted on the mounting support.

[0005] The tire described in WO2020 / 128225 comprises a rigidity structure- fication comprising first stiffening elements extending continuously in the toric cavity from the first bead to the apex and second stiffening elements extending continuously in the toric cavity from the second bead to the apex.

[0006] Each first and second stiffening element is attached to each bead from which it extends by means of 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 attached to the crown of the tire by means of a crown interface between the stiffening element and a portion of the inner surface of the crown. Each bead-crown interface comprises an elastomeric compound cushion positioned between the stiffening element and the portion of the corresponding internal surface.

[0007] It was noted that each bead and apex interface was subjected to tensile stress. Such interfaces are sensitive to repeated stresses which can lead to premature separation between the stiffening elements and the inner surface of the bead and / or the inner surface, and therefore to premature destruction of the stiffening structure.

[0008] The durability of the tire described in WO2020 / 128225 was improved in WO2022 / 200717 through the use of anchoring for each first and second stiffening element within the tire's internal structure. Nevertheless, the durability of the tire described in WO2022 / 200717, particularly the durability of the anchoring of the first and second stiffening elements in each first and / or second sidewall and / or bead, while significantly improved compared to that of the tire described in WO2020 / 128225, could not be further enhanced. Indeed, it was observed that the stiffening structure deteriorated due to the dislodging of the stiffening elements in one of the first and second beads.

[0009] The invention aims to improve the durability of the stiffening structure described in WO2020 / 128225 and to reduce the occurrence of dislodgement of the tire stiffening elements described in WO2022 / 200717. Description of the invention

[0010] The invention relates to a tire comprising a crown, first and second sidewalls each extending radially inwards from the crown, first and second beadings extending radially inwards respectively from the first and second sidewalls, the tire being provided with an internal surface delimiting a toroidal inflation cavity of the tire, the tire comprising a stiffening structure comprising at least a first stiffening element extending continuously in the toroidal 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 the crown by extending in the first sidewall and / or bead and / or the crown from a first anchoring point radially internal and / or external to the internal surface,

[0011] the tire comprising a sealing layer for at least one inflation gas forming part of the internal surface, or

[0012] the tire being devoid of a sealing layer to at least one inflation gas forming part of the internal surface,

[0013] pneumatic in which, where the pneumatic comprises a sealing layer for at least one inflation gas forming part of the internal surface, the the sealing layer is arranged so as to remain at a distance from said first radially internal and / or external anchoring point of said first stiffening element.

[0014] As explained below, the invention functions as soon as it is applied to only one side of the tire, here at least to the side comprising the first sidewall and / or bead. Advantageous embodiments allow the invention to be applied to both sides of the tire, although this is not necessary to realize the invention. Thus, in the present application, the use of the term "first" is intended, unless otherwise obviously interpreted, to associate the element designated as "first" with the first sidewall and / or bead. Similarly, the use of the term "second" is intended, unless otherwise obviously interpreted, to associate the element designated as "second" with the second sidewall and / or bead.

[0015] Advantageously, the first sidewall and / or bead is arranged on the same side of the tire's median plane as the outer side of the tire. Thus, the stiffening structure acts on the side of the tire most stressed during high drift conditions. By inner and outer sides, it is understood that the tire is designed so that one of its sides is arranged on the inside and the other on the outside. This orientation, imposed by the tire manufacturer, ensures that the tire performs as expected. Indeed, mounting a tire with an orientation different from that imposed by the manufacturer can lead to suboptimal vehicle behavior. By outer side, it is understood that the side of the tire is fully visible from outside the vehicle when the tire is mounted on the vehicle.The inside side refers to the side of the tire that faces the wheel well of the vehicle on which it is mounted. Generally, the tire has markings indicating the inside and outside sides.

[0016] In a preferred embodiment in which the stiffening structure performs its function on both sides of the median plane of the tire, thus enabling homogeneous tire behavior, the stiffening structure comprises at least one second stiffening element extending continuously into the toroidal cavity from at least the second flank and / or bead to at least the apex and being anchored in the second flank and / or bead and / or the apex by extending into the second flank and / or bead and / or the apex from a second radially internal and / or external anchoring point on the internal surface,

[0017] in the case where the tire includes a sealing layer for at least one inflation gas forming part of the internal surface,

[0018] the sealing layer is arranged so as to remain at a distance from said second radially internal and / or external anchoring point of said second stiffening element.

[0019] By keeping the sealing layer at a distance from at least one of the radially internal and / or external anchor points, the sealing layer prevents weakening the anchorage of the stiffening element at said radially internal and / or external anchor point. The absence of a sealing layer also achieves this effect. Indeed, the inventors of the invention discovered that the sealing layer could exhibit relatively weak adhesion to the stiffening element, which creates, in the prior art tire described in WO2022 / 200717, a singular zone conducive to the initiation of cracks at the anchorage in the sidewall and / or bead and / or crown. By keeping the sealing layer at a distance from the radially internal and / or external anchor point, or by removing the sealing layer altogether, the singular zone is eliminated, thus eliminating any risk of cracking.Furthermore, when the waterproofing layer is present, the waterproofing function of the waterproofing layer is retained, and at least part of the waterproofing performance.

[0020] By anchored in a side and / or bead and / or in the top, it is understood that the stiffening structure or the stiffening element penetrates the side and / or bead and / or the top, that is to say that the stiffening structure or the stiffening element passes through the internal surface to anchor itself in a side and / or bead and / or in the top.

[0021] By distance, it is understood that the sealing layer is not in contact with the relevant stiffening element at the relevant anchor point. The minimum distance between the sealing layer and said radially internal and / or external anchor point is determined by a person skilled in the art based on their mastery of the tire manufacturing process and also on the required sealing performance.

[0022] The layer is called a sealing layer because of its low permeability to the tire inflation gas. Such a sealing layer is such that a tire without the sealing layer exhibits higher permeability compared to a tire with the sealing layer.

[0023] Thus, an anchorage according to the invention is significantly more robust than the bead interfaces described in WO2020 / 128225 and makes it possible to eliminate the failure by dislodging of the stiffening structure described in WO2022 / 200717.

[0024] Preferably, the minimum distance between the sealing layer and said first and / or second radially internal and / or external anchor point is greater than or equal to 1 mm, preferably 5 mm.

[0025] In the case where the tire includes a sealing layer, the internal surface delimiting the toroidal inflation cavity of the tire is thus formed at least in part by the sealing layer and by one or more elastomeric compositions interposed between the sealing layer and the anchor point(s), the elastomeric composition or each elastomeric composition being distinct from the sealing layer.

[0026] In the case where the tire is without a sealing layer, the internal surface delimiting the toroidal inflation cavity of the tire is thus formed by one or more elastomeric compositions not having a sealing function.

[0027] The toroidal inflation cavity is intended to be pressurized by an inflation gas once the tire is mounted on a mounting support, most often a rim.

[0028] Among other advantages, the stiffening structure makes it possible to simultaneously increase the radial stiffness, axial stiffness and drift stiffness of the tire compared to a conventional tire not including a stiffening structure but also compared to tires including other stiffening structures, such as the one described in WO2017 / 005713.

[0029] By increasing radial stiffness, the stiffening structure limits radial deformation of the apex during rolling, and in particular, camber, i.e., radial deformation opposite to the contact patch of the tread surface in contact with the ground. Thus, during tire rotation, the stiffening structure limits the amplitude of cyclic deformations of the tire, and in particular of its tread, and therefore limits the resulting energy dissipation, which contributes to a reduction in rolling resistance. Furthermore, under radial loading, the value of the contact patch with the ground is not modified, which allows the same grip performance to be maintained as for the tire described in WO2017 / 005713.

[0030] By increasing axial and drift stiffness, the stiffening structure will contribute to improved behavior under transverse loading, for example during drifting. Furthermore, under transverse loading, the contact area with the ground ensures a more homogeneous distribution of contact pressures, thereby increasing transverse grip.

[0031] Furthermore, the stiffening structure participates at least partially in bearing the load applied to the tire, such that this applied load is jointly borne by the tire, thanks to its pneumatic and intrinsic structural rigidity, and by the stiffening structure. Thus, when the tire is subjected to a nominal radial load, a portion of the stiffening structure arranged opposite the contact area is placed in tension. In some embodiments, conversely, a portion of the stiffening structure arranged at the contact area is subjected to buckling in compression.

[0032] The presence of the stiffening structure thus makes it possible to reduce the contribution The tire's load-bearing capacity can be reduced, thus allowing for a decrease in structural rigidity, for example, by reducing the volume of the bead. Indeed, the bead of a conventional tire dissipates a significant amount of energy due to their volume and the hysteresis of their constituent elastomeric compound. Reducing their volume therefore significantly reduces rolling resistance.

[0033] The tire according to the invention has a substantially toroidal shape around an axis of revolution substantially coinciding 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.

[0034] By axial direction, we mean the direction substantially parallel to the axis of revolution of the tire, that is to say the axis of rotation of the tire.

[0035] By circumferential direction, we mean the direction which is substantially perpendicular to both the axial direction and to a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

[0036] By radial direction, we mean 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.

[0037] By median plane of the tire, noted M, we mean the plane perpendicular to the axis of rotation of the tire which is located at mid-axial distance of the two ribs and passes through the axial midpoint of the apex reinforcement.

[0038] By circumferential equatorial plane of the tire, denoted E, is meant, in a meridional 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 meridional 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 outermost radial point of the tread intended to be in contact with the ground and the innermost radial point of the tire intended to be in contact with a support, for example a rim.

[0039] By meridian plane, we mean a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0040] By radially inside, and radially outside respectively, we mean closer to the axis of rotation of the tire, and further from the axis of rotation of the tire respectively. By axially inside, and axially outside respectively, we mean closer to the median plane of the tire, and further from the median plane of the tire respectively.

[0041] By bead, we mean the radial portion of the tire designed to allow the tire to be attached to a mounting support, for example a wheel including a rim. Thus, each bead is specifically designed to be in contact with a rim hook, allowing it to be attached. The bead is therefore delimited radially internally by the radially inner end of the tire and radially externally by an axial line passing through the outermost radial point in contact with a standard rim as defined by the European Tyre and Rim Technical Organisation or "ETRTO", 2023 standard.

[0042] By sidewall, we mean the radial portion of the tire connecting the bead to the crown. The sidewall is radially delimited 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 as defined in the ETRTO 2023 standard manual. The edges are arranged on either side of the median plane of the tire and are 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 outermost radial point in contact with a standard rim as defined by the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2023.

[0043] Any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​going from more than a to less than b (i.e. excluding bounds a and b) while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​going from a to b (i.e. including the strict bounds a and b).

[0044] The tires of the invention are preferably intended for passenger vehicles as defined in the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2023. Such a tire has a cross-section in a meridian plane characterized by a section height H and a nominal section width SW as defined in the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2023. The values ​​of SW and H are indicated on the tire sidewall marking, for example as defined according to the ETRTO manual, 2023.

[0045] Preferably, the passenger vehicle tires to which the invention will advantageously be applied are such that the H / S ratio, expressed as a percentage, is at most 90 and at least 20, and the nominal section width SW is at least 115 mm and at most 385 mm. Furthermore, the hook diameter D, defining the diameter of the tire mounting rim, is at least equal to 12 inches and at most equal to 30 inches.

[0046] Conventionally, in a tire comprising a crown reinforcement and a carcass reinforcement, the crown includes a tread intended to contact the road surface and a crown reinforcement arranged radially within the tread. The carcass reinforcement is anchored in each bead and extends radially in each sidewall and axially in the crown, radially within the crown reinforcement. Conventionally, the crown reinforcement includes at least one crown layer comprising reinforcing elements. These reinforcing elements are preferably textile or metallic wire elements.

[0047] In embodiments enabling the performance of so-called radial tires as defined by ETRTO, the carcass reinforcement comprises at least one carcass layer, said carcass layer comprising wire carcass reinforcement elements, each wire carcass reinforcement element extending substantially along a principal direction forming with the circumferential direction of the tire an angle, in absolute value, ranging from 80° to 90°. Alternatively, a variable angle ranging from 80° to 90° may be used in at least a portion of the sidewall and strictly less than 80° in at least a portion of the crown.

[0048] In an advantageous embodiment, the stiffening structure is not airtight to the tire inflation gas. Thus, the stiffening structure allows the inflation gas to pass through. In other words, the stiffening structure does not define a secondary pressure cavity within the tire. By "not airtight," it is understood that the stiffening structure is permeable to the inflation gas so that the pressure is homogeneous in the toroidal cavity at all times, and in particular during tire inflation.

[0049] Advantageously, said first radially internal anchorage point of said first stiffening element and said first radially external anchorage point of said first stiffening element are arranged on the same side of the median plane of the tire.

[0050] Advantageously, said second radially internal anchorage point of said second stiffening element and said second radially external anchorage point of said second stiffening element are arranged on the same other side of the median plane of the tire.

[0051] Thus, the portions extending, on the one hand, between a radially inner anchor point and a radially outer anchor point located on the same side of the median plane, and on the other hand, between a radially inner anchor point and a radially outer anchor point located on the other side of the median plane, do not intersect, which makes it possible to limit the axial buckling of the tread, that is to say axial compression of the tread, particularly under conditions of high lateral stress. Thus, on the one hand, a regular contact area is maintained, and on the other hand, the risk of deterioration of the tire's crown reinforcement is reduced, in particular by avoiding compression of the various constituent elements of the crown reinforcement, for example textile and metal wire reinforcement elements of the crown reinforcement.

[0052] Preferably, the stiffening structure comprises a plurality of first stiffening elements distributed circumferentially in the toric cavity.

[0053] Optionally, the stiffening structure includes a plurality of second stiffening elements distributed circumferentially in the toric cavity.

[0054] In embodiments, at least a portion of said first stiffening element is coated with at least one layer of a polymeric composition, preferably an adhesive composition.

[0055] Optionally, at least a portion of said second stiffening element is coated with at least one layer of a polymeric composition, preferably an adhesive composition.

[0056] Such a layer of polymeric composition limits the propagation of air and any corrosive agents along the stiffening element and therefore within the tire structure. The composition is called polymeric because it is based on a polymeric composition; this polymeric composition may include one or more polymers, for example, chosen from thermoplastic polymers, thermosetting and / or crosslinkable polymers, elastomers, thermoplastic elastomers, as well as fillers and other components commonly used in tire compositions.

[0057] In some embodiments, the adhesive composition comprises a resin selected from aldehyde / phenol resins, polyepoxide resins, polyisocyanate resins, aromatic polyepoxy-phenolic resins, and multifunctional resins, as well as mixtures of these resins. In addition to limiting the spread of air and any corrosive agents, the adhesive composition improves the anchoring of the stiffening elements within the tire structure.

[0058] Advantageously, said first stiffening element comprises a portion extending continuously in the toroidal cavity from the first radially internal anchor point and the first radially external anchor point.

[0059] Advantageously, said first stiffening element comprises a radially internal anchoring portion of said first stiffening element extending from the first radially internal anchoring point in the first flank and / or bead and extending the portion extending continuously into the toric cavity.

[0060] Advantageously, said first stiffening element comprises a portion radially external anchoring of said first stiffening element extending from the first radially external anchoring point in the apex and extending the portion extending continuously into the toroidal cavity.

[0061] Optionally, said second stiffening element comprises a portion extending continuously into the toroidal cavity from the second radially internal anchor point and the second radially external anchor point.

[0062] Optionally, said second stiffening element includes a radially internal anchoring portion of said second stiffening element extending from the second radially internal anchoring point in the second flank and / or bead and extending the portion extending continuously into the toric cavity.

[0063] Optionally, said second stiffening element includes a radially external anchoring portion of said second stiffening element extending from the second radially external anchoring point in the apex and extending the portion extending continuously into the toroidal cavity.

[0064] In embodiments, said first stiffening element comprises a portion extending continuously in the toroidal cavity from said first radially internal anchorage point of said first stiffening element to said first radially external anchorage point of said first stiffening element, said portion extending continuously in the toroidal cavity being coated at least in part with the polymeric composition, preferably with an adhesive composition as described above.

[0065] Optionally, said second stiffening element comprises a portion extending continuously in the toroidal cavity from said second radially internal anchor point of said second stiffening element to said second radially external anchor point of said first stiffening element, said portion extending continuously in the toroidal cavity being coated at least in part with the polymeric composition, preferably with an adhesive composition as described above.

[0066] The polymeric composition here makes it possible to limit the propagation of air and any corrosive agents.

[0067] In one embodiment, said first stiffening element includes a radially internal anchoring portion extending into the first flank and / or bead from the first radially internal anchoring point, said radially internal anchoring portion is coated at least in part with the polymeric composition, preferably with an adhesive composition as described above.

[0068] Optionally, said second stiffening element includes a radially internal anchorage portion extending into the second flank and / or bead from said second radially internal anchorage point, said anchorage portion radially inner is coated at least in part with the polymer composition, preferably with an adhesive composition as described above.

[0069] The polymer composition here makes it possible to improve the anchoring of the stiffening elements in the first flank and / or bead and / or second flank and / or bead.

[0070] In one embodiment, said first stiffening element comprises a radially external anchoring portion extending into the top from said first radially external anchoring point, said radially external anchoring portion is coated at least in part with the polymeric composition, preferably with an adhesive composition as described above.

[0071] Optionally, said second stiffening element includes a radially external anchoring portion extending into the top from said second radially external anchoring point, said radially external anchoring portion is coated at least in part with the polymeric composition, preferably with an adhesive composition as described above.

[0072] The polymer composition here makes it possible to improve the anchoring of the stiffening elements in the apex.

[0073] In advantageous embodiments, the sealing layer comprises a so-called sealing composition comprising one or more butyl rubbers.

[0074] More preferably, the composition comprises at least 50 parts per cent of the butyl rubber(s). Thus, the butyl rubber(s) usable in the composition represent at least 50 parts per cent, that is to say, they represent at least 50% by weight of the total weight of the elastomer(s).

[0075] The term "part per percent 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 would mean, for example, 60 g of that constituent per 100 g of elastomer. In this application, the terms "elastomer" and "rubber" are used interchangeably throughout the text.

[0076] Butyl rubber means an isobutylene homopolymer or an isobutylene-isoprene copolymer, as well as halogenated derivatives, in particular generally brominated or chlorinated, of these isobutylene homopolymers and isobutylene-isoprene copolymers. Preferably, the butyl rubber(s) usable in the composition are selected from isobutylene rubbers, isobutylene-isoprene copolymers (IIR), bromobutyl rubbers such as bromoisobutylene-isoprene copolymer (BIIR), and chlorobutyl rubbers such as chloroisobutylene-isoprene copolymer (CIIR). By extension of the preceding definition, the term "butyl rubber" will also include isobutylene-styrene derivative copolymers such as isobutylene copolymers. and brominated methylstyrene (BIMS), which notably includes the elastomer called EXXPRO® marketed by the company Exxon.

[0077] Other elastomers present in the composition in addition to the butyl rubber(s) include, in particular, diene elastomers other than the butyl elastomers mentioned above. The term diene elastomer or rubber is understood to mean, 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 are, for example, described in WO2016 / 001226A1.

[0078] In embodiments promoting the endurance of the stiffening structure, the first flank and / or bead and / or the top comprises a first elastomeric composition in contact with said first stiffening element at the first radially internal and / or external anchoring point.

[0079] In the case where the tire includes a sealing layer for at least one inflation gas forming part of the inner surface, the first elastomeric composition is distinct from the sealing composition. In other words, said first elastomeric composition is interposed between said first stiffening element and the sealing layer at the first radially internal and / or external anchoring point.

[0080] Preferably, said first elastomeric composition comprises less than 50 parts per annum of butyl rubber, preferably less than 10 parts per annum of butyl rubber and is more preferably substantially free of butyl rubber.

[0081] Optionally, the second flank and / or bead and / or the top comprises a second elastomeric composition in contact with said second stiffening element at the second radially internal and / or external anchoring point.

[0082] In the case where the tire includes a sealing layer for at least one inflation gas forming part of the inner surface, the second elastomeric composition is distinct from the sealing composition. In other words, said second elastomeric composition is interposed between said second stiffening element and the sealing layer at the second radially inner and / or outer anchoring point.

[0083] Preferably, said second elastomeric composition comprises less than 50 parts per annum of butyl rubber, preferably less than 10 parts per annum of butyl rubber and is more preferably substantially free of butyl rubber.

[0084] Preferably, said first and / or second elastomeric composition comprises at least 50 parts of a diene elastomer.

[0085] In particularly preferred embodiments, said first and / or second elastomeric composition has a modulus at 10% extension of less than or equal to 8 MPa, preferably less than or equal to 5 MPa.

[0086] Such rigidity is relatively low and allows for the absorption of the large deformations applied to each stiffening element at the relevant anchor point. This improves the durability of the stiffening structure.

[0087] The modulus at 10% extension of the elastomeric composition is the elastic modulus of the elastomeric composition measured during a uniaxial tensile test, at an elongation value of 0.1 (i.e., 10% elongation, expressed as a percentage). A constant uniaxial tensile speed is applied to the specimen, and its elongation and the 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 measurement and results processing conditions for determining 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 taking the ratio of this stress value to the elongation value.A person skilled in the art will know how to choose and adapt the dimensions of the test specimen according to the amount of elastomeric composition accessible and available, particularly in the case of specimen sampling from tires.

[0088] Each elastomeric composition is said to be elastomeric because it is based on an elastomeric composition, this elastomeric composition being able to include one or more elastomers but also fillers and other components usually used in the field of compositions for tires.

[0089] In one embodiment, the pneumatic includes a first anchoring member arranged in the toroidal cavity and extending in projection from the first flank and / or bead towards the interior of the toroidal cavity and / or from the apex towards the interior of the toroidal cavity, being in contact at least locally with said first stiffening element.

[0090] Preferably, said first anchoring member is made of material with at least the first flank and / or ridge and / or with the apex.

[0091] Advantageously, said first anchoring member is made at least in part in said first elastomeric composition.

[0092] Optionally, the tire includes a second anchoring member arranged in the toroidal cavity and extending in projection from the second flank and / or bead towards the interior of the toroidal cavity and / or from the apex towards the interior of the toroidal cavity, being in contact at least locally with said second stiffening element.

[0093] Preferably, said second anchoring member is made of material with at least the second flank and / or ridge and / or with the top.

[0094] Advantageously, said second anchoring member is made at least in part in said second elastomeric composition.

[0095] Such anchoring elements make it possible to reinforce the interface between the stiffening structure and the internal surface and to limit interface failure resulting from repeated stresses exerted by the stiffening structure on the interface. This improves the endurance of the stiffening structure. Indeed, such anchoring of the stiffening structure allows the stresses to be distributed within the anchoring element, thus resulting in an anchor with improved robustness.

[0096] By "coming from the material," it is understood that the corresponding anchoring element is not attached subsequently to the tire's cross-linking, for example, by bonding after the tire's cross-linking. Thus, the corresponding anchoring element is cross-linked simultaneously with the first or second sidewall and / or bead and / or with the top.

[0097] According to a first particular design of the tire, the stiffening structure comprising a plurality of first stiffening elements distributed circumferentially in the toroidal cavity, the sealing layer leaves the following in the toroidal cavity:

[0098] - a first continuous circumferential band of radially inner anchoring arranged so that the sealing layer remains at a distance from said first radially internal anchor point of each first stiffening element of the plurality of first stiffening elements, and / or

[0099] - a first continuous circumferential band of radially external anchoring arranged so that the sealing layer remains at a distance from said first radially external anchor point of each first stiffening element of the plurality of first stiffening elements.

[0100] By continuous, it is understood that the continuous circumferential band of radially internal and / or external anchorage does not have any interruption in the circumferential direction between its possible circumferential ends. Thus, two adjacent radially internal and / or external anchorage points of the plurality of radially internal and / or external anchorage points are joined by at least a portion of the continuous circumferential band of radially internal and / or external anchorage.

[0101] Each first continuous circumferential band of radially internal and / or external anchoring forms part of the internal surface delimiting the internal cavity.

[0102] In certain preferred embodiments, said first continuous radial inner and / or outer anchoring band extends circumferentially over at least 50% of the circumference of the tire, preferably over the entire circumference of the tire. In other embodiments, the pneumatic includes several first continuous circumferential radially internal disjointed anchoring bands.

[0103] Optionally, the stiffening structure comprising a plurality of second stiffening elements distributed circumferentially in the toroidal cavity, the sealing layer leaves the following in the toroidal cavity:

[0104] - a second continuous radially inner circumferential anchoring band arranged so that the sealing layer remains at a distance from said second radially internal anchor point of each second stiffening element of the plurality of second stiffening elements, and / or

[0105] - a second continuous radially external circumferential anchoring band arranged so that the sealing layer remains at a distance from said second radially external anchor point of each second stiffening element of the plurality of second stiffening elements.

[0106] Each second continuous circumferential band of radially internal and / or external anchoring forms part of the internal surface delimiting the internal cavity.

[0107] Optionally, said second continuous radial inner and / or outer anchoring band extends circumferentially over at least 50% of the tire's circumference, preferably over the entire circumference of the tire. In other embodiments, the tire comprises several disjointed second continuous radial inner anchoring bands.

[0108] In this first design, said first and / or second continuous circumferential band of radially internal and / or external anchorage preferably comprises respectively the first and / or second elastomeric composition distinct from the sealing composition, the first and / or second elastomeric composition being in contact with said first and / or second stiffening element at the first and / or second radially internal and / or external anchorage point.

[0109] According to a second particular design of the tire, the stiffening structure comprising a plurality of first stiffening elements, the sealing layer leaves the following in the toroidal cavity:

[0110] - a plurality of distinct radially interior first reservations, each the first radially internal reservation of the plurality of first radially internal reservations is arranged so that the sealing layer remains at a distance from said first radially internal anchor point of each first stiffening element of the plurality of first stiffening elements, [YES] and / or

[0112] - a plurality of distinct radially external first reservations, each first reservation radially outside the plurality of first reservations radially external is arranged so that the sealing layer remains at a distance from said first radially external anchor point of each first stiffening element of the plurality of first stiffening elements.

[0113] By distinct, it is understood that there is a portion of the sealing layer separating two distinct radially internal and / or external recesses. Thus, two distinct radially internal and / or external anchor points from the plurality of radially internal and / or external anchor points are separated by at least a portion of the sealing layer.

[0114] Optionally, the stiffening structure comprising a plurality of second stiffening elements, the sealing layer leaves the following in the toroidal cavity:

[0115] - a plurality of distinct radially interior second reservations, each second radially internal reservation of the plurality of second radially internal reservations is arranged so that the sealing layer remains at a distance from said second radially internal anchor point of said second stiffening element of the plurality of second stiffening elements,

[0116] and / or

[0117] - a plurality of distinct radially external second reservations, each second radially external reservation of the plurality of second radially external reservations is arranged so that the sealing layer remains at a distance from said second radially external anchor point of each second stiffening element of the plurality of second stiffening elements.

[0118] Thus, the sealing of the toroidal cavity of the tire is improved by reducing as much as possible the portion of the internal surface not made up of the sealing layer.

[0119] In this second design, each first and / or second radially internal and / or external reservation preferably comprises respectively the first and / or second elastomeric composition distinct from the sealing composition, the first and / or second elastomeric composition being in contact with said first and / or second stiffening element at the first and / or second radially internal and / or external anchoring point.

[0120] Thus, whether in the first or second design described above, the sealing layer comprises, in embodiments, a first continuous circumferential radially inward sealing strip extending between a radially inward end of said first bead and said first radially inward anchor point of each first stiffening element of the plurality of first stiffening elements, remaining at a distance from each first radially inward anchor point of each first stiffening element of the plurality of initial stiffening elements, and / or

[0121] - a first continuous radially external circumferential sealing strip extending axially towards the second flank from said first radially external anchor point of each first stiffening element of the plurality of first stiffening elements, remaining at a distance from said first radially external anchor point of each first stiffening element of the plurality of first stiffening elements, and / or

[0122] - a first continuous circumferential band of intermediate sealing extending between said first radially internal anchorage point of each first stiffening element of the plurality of first stiffening elements and said first radially external anchorage point of each first stiffening element of the plurality of first stiffening elements while remaining at a distance from said first radially internal anchorage point of each first stiffening element of the plurality of first stiffening elements and at a distance from said first radially external anchorage point of each first stiffening element of the plurality of first stiffening elements.

[0123] Each first continuous circumferential band of radially inner, radially outer and intermediate sealing forms part of the internal surface delimiting the internal cavity.

[0124] In the first design described above, each first continuous circumferential band of radially inner, radially outer and intermediate sealing is, except at its possible circumferential ends, disjointed from each other first continuous circumferential band of radially inner, radially outer and intermediate sealing.

[0125] In the second design described above, each first continuous circumferential radially inner, radially outer and intermediate sealing strip is joined with at least one other of the first continuous circumferential radially inner, radially outer and intermediate sealing strips.

[0126] Optionally, in either the first or second design described above, the sealing layer comprises a second continuous circumferential radially inward sealing strip extending between a radially inward end of said second bead and said second radially inward anchor point of each second stiffening element of the plurality of second stiffening elements, remaining at a distance from said second radially inward anchor point of each second stiffening element of the plurality of second stiffening elements, and / or

[0127] - a second continuous radially external circumferential sealing band extending axially towards the first flank from said second anchor point ra- radially external to each second stiffening element of the plurality of second stiffening elements, remaining at a distance from said second anchor point radially external to each second stiffening element of the plurality of second stiffening elements, and / or

[0128] - a second continuous circumferential intermediate sealing band extending between said second radially internal anchor point of each second stiffening element of the plurality of second stiffening elements and said second radially external anchor point of each second stiffening element of the plurality of second stiffening elements, remaining at a distance from said second radially internal anchor point of each second stiffening element of the plurality of second stiffening elements and at a distance from said second radially external anchor point of each second stiffening element of the plurality of second stiffening elements.

[0129] Each second continuous circumferential band of radially inner, radially outer and intermediate sealing forms part of the internal surface delimiting the internal cavity.

[0130] Thus, the sealing of the toroidal cavity of the tire is improved, each of the first and / or second radially internal, external and intermediate circumferential bands increasing the surface area of ​​the sealing layer without diminishing the endurance of the anchoring of said first and / or second stiffening element at each first and / or second radially internal and / or external anchoring point.

[0131] In the first design described above, each second continuous circumferential band of radially inner, radially outer and intermediate sealing is, except at its possible circumferential ends, disjointed from each other second continuous circumferential band of radially inner, radially outer and intermediate sealing.

[0132] In the second design described above, each second continuous circumferential sealing band radially inner, radially outer and intermediate is joined with at least one other of the second continuous circumferential sealing bands radially inner, radially outer and intermediate.

[0133] In a first configuration of the stiffening elements, each first stiffening element forms a continuous first stiffening element that meanders at least from the first flank and / or bead through the top. Preferably also, each second stiffening element forms a continuous second stiffening element that meanders at least from the second flank and / or bead through the top.

[0134] Thus, the manufacturing of the tire is facilitated and the robustness of the The stiffening structure is achieved by removing the ends of the stiffening element anchored to each sidewall and / or bead and / or the crown. In this initial configuration, a continuous stiffening element extending around the entire circumference of the tire is possible. Because this stiffening element is continuous, the transmission of forces between each sidewall and / or bead is improved, as the forces are distributed across the tire. Thus, the stiffening structure performs its function around the entire circumference of the tire.

[0135] 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 to the second flank and / or bead via the top so as to meander from the first flank and / or bead to the second flank and / or bead.

[0136] According to a second variant of the first configuration of the stiffening elements, each first stiffening element forms a continuous stiffening element that meanders between the first flank and / or bead and the apex. Also in this second variant, each second stiffening element forms a continuous stiffening element that meanders between the second flank and / or bead and the apex.

[0137] In a second configuration of the stiffening elements, it may be envisaged that each first stiffening element extends from the first flank and / or bead to the apex and has one end in the first flank and / or bead. Similarly, it may be envisaged that each second stiffening element extends from the second flank and / or bead to the apex and has one end in the second flank and / or bead.

[0138] In a first variant of this second configuration, it may be envisaged that each first stiffening element extends from the first side and / or bead to the apex and has one end at the apex. Similarly, it may be envisaged that each second stiffening element extends from the second side and / or bead to the apex and has one end at the apex.

[0139] In a second variant of this second configuration, each first stiffening element is respectively each second stiffening element and extends from the first flank and / or bead to the second flank and / or bead via the top and has an end in each first and second flank and / or bead.

[0140] Each stiffening element according to one of the designs or configurations defined above can be characterized geometrically, in particular by its cross-section The average cross-sectional area Sm is the average of the cross-sectional areas obtained by cutting the stiffening element through all cylindrical surfaces coaxial with the tire and radially contained within the inner toroidal cavity. In the most frequent case of a constant cross-section, the average cross-sectional area Sm is the constant cross-sectional area of ​​the stiffening element. The average cross-sectional area Sm comprises a larger characteristic dimension Dmax and a smaller characteristic dimension Dmin, the ratio of which R = Dmax / Dmin is called the aspect ratio.For example, a stiffening element having a circular mean cross-section Sm, with a diameter equal to d, has a form ratio R=l, a stiffening element having a rectangular mean cross-section Sm, with a length L and a width 1, has a form ratio R=L / 1, and a stiffening element having an elliptical mean cross-section Sm, with a major axis D and a minor axis d, has a form ratio R=D / d.

[0141] A first preferred type of stiffening element, with a form ratio R of at most 3, is called one-dimensional. In other words, a stiffening element is considered one-dimensional when the largest characteristic dimension Dmax of its average cross-section Sm is at most 3 times the smallest characteristic dimension Dmin of its average cross-section Sm. A one-dimensional stiffening element has a wire-like mechanical behavior, that is, it can only be subjected to tensile or compressive forces along its neutral axis. This is why a one-dimensional stiffening element is usually called a wire-like stiffening element.Among the components commonly used in the field of pneumatics, textile filament 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 cross-section Sm being substantially circular, the shape ratio R is equal to 1, therefore less than 3.

[0142] A second type of stiffening element, with a aspect ratio R of at least 3, is called two-dimensional. In other words, a stiffening element is considered two-dimensional when the largest characteristic dimension Dmax of its average cross-section Sm is at least 3 times the smallest characteristic dimension Dmin of its average cross-section Sm. A two-dimensional stiffening element has membrane-like mechanical behavior, meaning that it can only be subjected to tensile or compressive forces within its thickness, defined by the smallest characteristic dimension Dmin of its average cross-section Sm. According to a first embodiment, a stiffening element, with an aspect ratio R A stiffening element with a ratio R of at least 3 and at most 50 is called a two-dimensional strip element. According to a second variant, a stiffening element with a ratio R of at least 50 is called a two-dimensional film element.

[0143] The materials that can be used for each stiffening element are as described in WO2022 / 200717.

[0144] In a highly advantageous embodiment, the first and / or second stiffening element(s) are 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, they have identical geometric characteristics and constituent materials.

[0145] These wire stiffening elements are commonly called stays. The advantage of using wire stiffening elements is that they result in a stiffening structure with low mass and minimal hysteresis. Using identical wire stiffening elements ensures a homogeneous distribution of forces among the stiffening elements.

[0146] By textile, it is understood that each wire stiffening element is non-metallic, for example made of a material selected from polyester, polyamide, polyketone, polyvinyl alcohol, cellulose, mineral fiber, natural fiber, elastomeric material, or a mixture of these materials. Examples of polyesters include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PBN (polybutylene naphthalate), PPT (polypropylene terephthalate), and PPN (polypropylene naphthalate). Examples of polyamides include 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.

[0147] Advantageously, in an embodiment enabling the tire to be manufactured using a relatively simple process, each wire stiffening element extends in the toroidal cavity along a principal direction forming, with the circumferential direction of the tire, an angle ranging, in absolute value, from 85° to 90°. In another embodiment enabling the tire to be manufactured using a more complex process but enabling the circumferential stiffness to be increased, each wire stiffening element extends in the toroidal cavity along a principal direction forming, with the circumferential direction of the tire, an angle ranging, in absolute value, from 45° to 85° as explained in particular in WO2020 / 128225.

[0148] Preferably, the stiffening structure or said first stiffening element extending from the first flank and / or bulge to the top or said portion The radially internal anchorage of said first stiffening element is anchored in the first flank and / or bead by being anchored in or around a first radially internal reinforcement structure of the stiffening structure arranged in the first flank and / or bead. Preferably also, the stiffening structure or said first stiffening element extending from the first flank and / or bead to the apex, or said radially external anchorage portion of said first stiffening element, is anchored in the apex by being anchored in or around one or more radially external reinforcement structures of the stiffening structure arranged in the apex.

[0149] Alternatively, the stiffening structure or said first stiffening element extending from the first flank and / or bead to the apex, or said radially inner anchoring portion of said first stiffening element, is anchored in the first flank and / or bead by being anchored in an elastomeric mass of said first flank and / or bead. Also alternatively, the stiffening structure or said first stiffening element extending from the first flank and / or bead to the apex, or said radially outer anchoring portion of said first stiffening element, is anchored in the apex by being anchored in an elastomeric mass of said apex.

[0150] Optionally, the stiffening structure or said second stiffening element extending from the second flank and / or bead to the apex, 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 reinforcement 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 apex, or said radially outer anchoring portion of said second stiffening element, is anchored in the apex by being anchored in or around one or more radially outer reinforcement structures of the stiffening structure arranged in the apex.

[0151] Alternatively, the stiffening structure or said second stiffening element extending from the second flank and / or bead to the apex, or said radially inner anchoring portion of said second stiffening element, is anchored in the second flank and / or bead by being anchored in an elastomeric mass of said second flank and / or bead. Also alternatively, the stiffening structure or said second stiffening element extending from the second flank and / or bead to the apex, or said radially outer anchoring portion of said second stiffening element, is anchored in the apex by being anchored in an elastomeric mass of said apex.

[0152] Of course, the tire can include both the first and second radially inner reinforcement structures and the radially outer reinforcement structure(s), or only the first and second radially inner reinforcement structures, or only the radially outer reinforcement structure(s).

[0153] Each radially internal or external reinforcing structure is respectively arranged in the corresponding side and / or flange or in the top, that is to say, arranged radially within the internal surface and embedded in the mass of materials constituting the corresponding side and / or flange or the top. The stiffening structure passes through the internal surface to be anchored in or around the corresponding radially internal reinforcing structure and / or through the internal surface to be anchored in or around the one or more of the radially external reinforcing structure(s).

[0154] As previously stated, the stiffening structure can be anchored in or around at least one radially internal and / or external reinforcing structure.

[0155] Thus, in a first variant, the stiffening structure can be anchored in the very structure of said reinforcement structure, that is to say that the stiffening structure penetrates at least in part into said reinforcement structure, or even crosses it totally so that said reinforcement structure forms a mechanical anchor of the stiffening structure.

[0156] In particular, where said reinforcement 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 reinforcement structure so as to pass through it.

[0157] In a second variant, the stiffening structure can be anchored around the structure of said reinforcement structure itself, that is to say that the stiffening structure rests on said reinforcement structure so that said reinforcement structure takes up part of the forces exerted on the stiffening structure and anchors the stiffening structure in the side and / or the bulge or the top.

[0158] In particular, in the case where said reinforcement 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 reinforcement structure without passing through it.

[0159] In embodiments comprising a first radially internal reinforcing structure arranged in the first flank and / or bead, this preferably includes at least one first circumferential radially internal reinforcing element allowing the anchoring of the stiffening structure.

[0160] In embodiments comprising a second reinforcing structure ra- internally arranged in the second flank and / or bead, this preferably includes at least one second circumferential internal radial reinforcement element allowing the anchoring of the stiffening structure.

[0161] In a preferred embodiment, each first and second bead comprises respectively a first and second circumferential radially internal reinforcement element intended to allow the tire to be attached to a tire mounting support, said first circumferential radially internal reinforcement element or each first and second circumferential radially internal reinforcement element being arranged radially outside each first and second circumferential reinforcement element intended to allow the tire to be attached to a tire mounting support.

[0162] Thus, the propagation of noise generated by the stiffening structure from the stiffening structure to the vehicle via the tire mounting bracket is reduced. Indeed, the noise generated by the stiffening structure is dampened by the tire structure separating the considered radially inner circumferential reinforcement element from the radially inner circumferential reinforcement element intended to allow the tire to be attached to a tire mounting bracket located on the same side of the tire's median plane.

[0163] This damping is the result of the fact that the circumferential radially internal reinforcement element considered is mechanically decoupled from said circumferential radially internal reinforcement 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.

[0164] Alternatively, said first internal radially reinforcing circumferential element or each first and second internal radially reinforcing circumferential element is intended to allow the tire to be attached to a tire mounting support.

[0165] In one embodiment, said first internal radially reinforcing circumferential element or each first and second internal radially reinforcing circumferential element is a wire reinforcing element extending along a principal 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.

[0166] In embodiments comprising at least one radially external reinforcing structure arranged in the top, this preferably comprises at least one circumferential radially external reinforcing element.

[0167] In one embodiment, said radially external circumferential reinforcing element of the or each radially external reinforcing structure is an element of wire reinforcement extending along 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.

[0168] In certain embodiments, the tire comprises first and second radially external reinforcement structures. In these embodiments, preferably, each first and second radially external reinforcement structure comprises respectively a first and second circumferential radially external reinforcement element, the first circumferential radially external reinforcement element being arranged at an axial distance from said second circumferential radially external reinforcement element.

[0169] This makes it possible to reduce the mass of the reinforcing structure allowing the anchoring of the stiffening structure in the top and to limit the over-fretching of the top thus allowing to maintain a regular contact area.

[0170] Preferably, the first radially external circumferential reinforcement element and the second radially external circumferential reinforcement element are arranged on either side of the median plane of the tire.

[0171] Thus, the axial distribution of the forces exerted by the stiffening structure on the apex is improved.

[0172] Each internal radially internal circumferential reinforcing element and each external radially external circumferential reinforcing element may be wound in various ways as described in particular in WO2022 / 200717.

[0173] Of course, the tire may include several of the said first and / or second radially internal and / or external reinforcement structures. Brief description of the drawings

[0174] The present invention will be better understood upon study of the detailed description of embodiments, taken by way of non-limiting examples and illustrated by the accompanying drawings in which:

[0175] [Fig-1] is a view of a tire in a meridian cutting plane parallel to the axis of rotation according to a first embodiment of the invention;

[0176] [Fig.2] is a schematic perspective view of the inside of the tire of [Fig.1];

[0177] [Fig.3] is a view analogous to that of [Fig.2] of a tire according to a second embodiment of the invention; and

[0178] [Fig.4] and [Fig.5] are views analogous to those in [Fig.1] and [Fig.2] of a tire according to a third embodiment of the invention. Detailed description

[0179] In the figures relating to the tire, a coordinate system X, Y, Z has been represented. corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0180] The figures represent a tire 10 having a substantially toroidal shape about an axis of revolution substantially parallel to the axial direction Y. The tire 10 is intended for a passenger vehicle and has a size of 275 / 35ZR19. In the various figures, the tire 10 is shown in its new condition, i.e., not yet having been driven on.

[0181] The tire 10 includes a crown 12 comprising a tread 14 intended to come into contact with a ground during rolling and a crown reinforcement 16 extending into the crown 12 in the circumferential direction X. The tire 10 also includes a sealing layer 18 for an inflation gas, in particular a sealing layer 18 comprising 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 parts per cent of the butyl rubber(s).

[0182] The tire 10 further includes a top reinforcement identical to that described WO2022 / 200717 comprising a working reinforcement 20 comprising working layers 24, 26 and a shrink-fit reinforcement 22 comprising a shrink-fit layer 28.

[0183] The tire 10 comprises first and second sidewalls 30A, 30B extending radially inward from the apex 12. The second sidewall 30B is opposite the first sidewall 30A with respect to the median plane M. The tire 10 further comprises first and second bead 32A, 32B extending radially inward from each first and second sidewall 30A, 30B, respectively. The second bead 32B is opposite the first bead 32A with respect to the median plane M. Each first and second sidewall 30A, 30B connects each first and second bead 32A, 32B, respectively, to the apex 12. An internal surface 34, intended to be in contact with the inflation gas of the tire, defines a toroidal inflation cavity 36 for the tire 10.

[0184] The tire 10 includes first and second radially internal reinforcement structures 3 8A, 38B respectively arranged in each first and second bead 32A, 32B.

[0185] Each first and second radially internal reinforcing structure 38A, 38B respectively comprises first and second circumferential radially internal 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.

[0186] Each first and second bead 32A, 32B comprises respectively a first and second circumferential internal radial reinforcement element 42A, 42B, here a rod, intended to allow the tire 10 to be attached to a tire mounting support 10, for example a rim.

[0187] Each first and second radially internal circumferential reinforcement element 40A, 40B is respectively arranged radially outside each first and second radially internal circumferential reinforcement element 42A, 42B intended to allow the tire 10 to be attached to a tire mounting support 10.

[0188] The tire 10 further comprises first and second radially external reinforcement structures 44A, 44B arranged in the apex 12 and each respectively provided with a first and second circumferential radially external reinforcement 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 circumferential radially external reinforcement element 46A, 46B is as described in WO2022 / 200717.

[0189] The tire 10 includes a carcass reinforcement 48 anchored in each first and second bead 32A, 32B, in this case wrapped around each first and second radially internal circumferential reinforcement element 42A, 42B intended to allow the tire 10 to be attached to a tire mounting support 10. The carcass reinforcement 48 extends into each first and second bead 32A, 32B and into each first and second sidewall 30A, 30B such that each first and second radially internal circumferential reinforcement element 40A, 40B is arranged radially inside the carcass reinforcement 48. The carcass reinforcement 48 also extends radially into the crown 12, internally to the crown reinforcement 16. The crown reinforcement 16 is arranged radially between the tread 14 and carcass reinforcement 48. The carcass reinforcement 48 comprises at least one layer of carcass 50 and here comprises a single layer of carcass 50..

[0190] The various top layers 24, 26, 28 and carcass 50 are identical to those described in WO2022 / 200717.

[0191] The tire 10 includes a stiffening structure 52 extending in the toroidal cavity 36 from the first bead 32A to the apex 12 and anchored in the first bead 32A by being anchored around the first radially internal reinforcing structure 38A. The stiffening structure 52 extends in the toroidal cavity 36 from the second bead 32B to the apex 12 and is anchored in the second bead 32B by being anchored around the second radially internal reinforcing structure 38B. The stiffening structure 52 extends in the toroidal cavity 36 from the first bead 32A and from the second bead 32B. up to the top 12 and is anchored in the top 12 by being anchored around the radially external reinforcing structures 44A, 44B.

[0192] 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.

[0193] Each stiffening element 54 is a textile yarn stiffening element comprising an assembly of three multifilament strands of aliphatic polyamide, for example nylon, these three multifilament strands being individually helicalized at 190 turns per meter in one direction and then helicalized together at 190 turns per meter in the opposite direction. Each of these multifilament strands has a fiber count of 188 tex.

[0194] Each first stiffening element 54A extends continuously from the first side 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 side 30A and / or the second bead 32A to the top 12 and here from the second bead 32A to the top 12.

[0195] In order to ensure optimal anchoring of the first and second stiffening elements 54A, 54B, each first and second radially internal reinforcement structure 3 8A, 38B, in particular each first and second circumferential radially internal reinforcement element 40A, 40B, has relatively large extension and bending stiffnesses.

[0196] In order to ensure optimal anchoring of the first and second stiffening elements 54A, 54B, each first and second radially external reinforcement structure 44A, 44B, in particular each first and second circumferential radially external reinforcement element 46A, 46B, has a relatively high tensile stiffness and a relatively low flexural stiffness in order to limit over-fretching of the top 12 and not risk damaging the flatness of the tread 14.

[0197] Each first stiffening element 54A is anchored, in the first bead 32A, around the first radially internal reinforcing structure 38A, in particular around the first circumferential radially internal reinforcing element 40A. Each second stiffening element 54B is anchored in the second bead 32B, around the second radially internal reinforcing structure 38B, in particular around the second circumferential radially internal reinforcing element 40B. Here, each first and second stiffening element 54A, 54B is wrapped at least partially respectively around each first and second circumferential element 54A, 54B. internal radial reinforcement conference 40A, 40B.

[0198] Each first and second stiffening element 54A, 54B is also anchored, in the apex 12, respectively around each first and second radially external reinforcing structure 44A, 44B, in particular around each first and second circumferential radially external reinforcing element 46A, 46B. Here, each first and second stiffening element 54A, 54B is wrapped at least partially respectively around each first and second circumferential radially external reinforcing element 46A, 46B.

[0199] Each first stiffening element 54A passes through the internal surface 34 at a first radially internal anchor point 56A in the first bead 32A to anchor around the first radially internal reinforcement structure 38A and at a first radially external anchor point 58A in the apex 12 to anchor around the first radially external reinforcement 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 internal anchor point 56A. Each first stiffening element 54A is anchored in the apex 12 by extending into the apex 12 from the first radially external anchor point 58A.

[0200] Each second stiffening element 54B passes through the internal surface 34 at a second radially internal anchor point 56B in the second flange 32B to anchor around the second radially internal reinforcement structure 38B and at a second radially external anchor point 58B in the apex 12 to anchor around the second radially external reinforcement structure 44B. Thus, each second stiffening element 54B is anchored in the second flange 32B by extending into the second flange 32B from the second radially internal anchor point 56B. Each second stiffening element 54B is anchored in the apex 12 by extending into the apex 12 from the second radially external anchor point 58B.

[0201] Each first stiffening element 54A comprises a radially internal anchoring portion 541, a portion 543, and a radially external anchoring portion 545, the portion 543 being extended on one side by the radially internal anchoring portion 541 and on the other side by the radially external anchoring portion 545.

[0202] Each second stiffening element 54B comprises a radially internal anchoring portion 542, a portion 544, and a radially external anchoring portion 546, the portion 544 being extended on one side by the radially internal anchoring portion 542 and on the other side by the radially external anchoring portion 546.

[0203] The portion 543 of each first stiffening element 54A extends continuously in the toric cavity 36 from the first radially internal anchor point 56A to the first radially external anchor point 58A.

[0204] The portion 544 of each second stiffening element 54B extends in the toroidal cavity 36 from the second radially internal anchor point 56B to the second radially external anchor point 58B.

[0205] The radially internal anchorage portion 541 of each first stiffening element 54A extends from the first radially internal anchorage point 56A in the first bead 32A to anchor around the first radially internal reinforcing structure 38A.

[0206] The radially external anchorage portion 545 of each first stiffening element 54A extends from the first radially external anchorage point 58A in the apex 12 to anchor around the first radially external reinforcing structure 44A.

[0207] The radially internal anchorage portion 542 of each second stiffening element 54B extends from the second radially internal anchorage point 56B in the second bead 32B to anchor around the second radially internal reinforcing structure 38B.

[0208] The radially external anchorage portion 546 of each second stiffening element 54B extends from the second radially external anchorage point 58B in the apex 12 to anchor around the second radially external reinforcing structure 44B.

[0209] Each first stiffening element 54A forms a first continuous stiffening element which meanders from the first bead 32A through the apex 12 and each second stiffening element 54B forms a second continuous stiffening element which meanders at least from the second bead 32B 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 through the apex 12 so as to meander from the first bead 32A to the second bead 32B.

[0210] The sealing layer 18 is formed inside the tire 10 so as to remain away from the first radially internal and external anchor points 56A, 58A of each first stiffening element 54A. The sealing layer 18 is further formed so as to remain away from the second radially internal and external anchor points 56B, 58B of each second stiffening element 54B.

[0211] Each first and second stiffening element 54A, 54B, in particular each portion 541, 543, 545, 542, 544, 546 is entirely covered with a com adhesive position, 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.

[0212] As illustrated in [Fig. 1], the first radially external anchor point 58A is arranged axially on the same side as the first radially internal anchor point 56A and the first radially internal reinforcing structure 38A with respect to the median plane M. The second radially external anchor point 58B is arranged axially on the opposite side of the second radially internal anchor point 56B and the second radially internal reinforcing structure 38B with respect to the median plane M. Each first and second radially internal anchor point 56A, 56B and external anchor point 58A, 56B is arranged so that the portions 543, 544 do not intersect in the toric cavity 36.

[0213] With reference to Figures 1 and 2, the sealing layer 18 comprises a first continuous circumferential radially inner sealing strip 181 extending between a radially inner end of the first bead 32A and each first radially inner anchor point 56A, remaining at a distance from each first radially inner anchor point 56A, these radially inner anchor points 56A being here substantially on the same circumferential line.

[0214] The sealing layer 18 comprises a first continuous circumferential radially external sealing band 185 extending towards the second sidewall 30B and here between the median plane M of the tire 10 and each radially external anchor point 58A, remaining at a distance from each radially external anchor point 58A, these radially external anchor points 58A being here substantially on the same circumferential line.

[0215] The sealing layer 18 comprises a first continuous circumferential intermediate sealing strip 183 extending between each first radially internal anchor point 56A and each first radially external anchor point 58A, remaining at a distance from each first radially internal anchor point 56A and at a distance from each first radially external anchor point 58A.

[0216] The sealing layer 18 also includes a second continuous circumferential radially internal sealing band 182 extending between a radially internal end of the second bead 32B and each radially internal anchor point 56B, remaining at a distance from each radially internal anchor point 56B, these radially internal anchor points 56B being here substantially on the same circumferential line.

[0217] The sealing layer 18 comprises a second continuous radially external circumferential sealing strip 186 extending towards the first flank 30A and here between the median plane M of the tire 10 and each radially external anchor point 58B, while remaining at a distance from each radially external anchor point 58B, these radially external anchor points 58B being here substantially on the same circumferential line.

[0218] The sealing layer 18 comprises a second continuous circumferential intermediate sealing strip 184 extending between each second radially inside anchor point and each second radially outside anchor point, remaining at a distance from each second radially inside anchor point 56B and at a distance from each second radially outside anchor point 58B.

[0219] The second radially external continuous circumferential band 186 extends axially from the first radially external circumferential band 185, so that the first and second radially external circumferential bands 185, 186 form a single radially external continuous circumferential band. Alternatively, the first and second radially external continuous circumferential bands 185, 186 could be spaced apart.

[0220] Each of the first and second continuous radial inner circumferential sealing bands 181, 182, outer 185, 186 and intermediate 183, 184 extends circumferentially over at least 50% of the circumference of the tire and here over the entire circumference of the tire, i.e. over 360 degrees.

[0221] With reference to figures 1 and 2, the sealing layer 18 leaves in the toroidal cavity 36 a first continuous circumferential radially internal anchoring band 60A arranged so that the sealing layer 18 remains at a distance from each radially internal anchoring point 56A and a first continuous circumferential radially external anchoring band 62A arranged so that the sealing layer 18 remains at a distance from each radially external anchoring point 58A.

[0222] The sealing layer 18 also leaves in the toroidal cavity 36 a second continuous circumferential radially internal anchoring band 60B arranged so that the sealing layer 18 remains at a distance from each second radially internal anchoring point 56B and a second continuous circumferential radially external anchoring band 62B arranged so that the sealing layer 18 remains at a distance from each second radially external anchoring point 58B.

[0223] The minimum distance Lmin between the sealing layer 18 and each first and second radially internal anchor point 56A, 56B and external 58A, 58B is greater than or equal to 1 mm, preferably 5 mm and here equal to 6 mm.

[0224] Thus, each radially internal anchor point 56A is arranged in the first radially internal circumferential elastomeric band 60A and each point radially external anchorage 58A is arranged in the first radially external circumferential elastomeric band 62A.

[0225] Also, each radially internal anchor point 56B is arranged in the second radially internal circumferential elastomeric band 60B and each radially external anchor point 58B is arranged in the second radially external circumferential elastomeric band 62B.

[0226] Each first and second continuous radial sealing band radially inner 181, 182, outer 185, 186 and intermediate 183, 184 forms a portion of the inner surface 34 of the toric cavity 36. Each first and second continuous radial anchoring band radially inner 60A, 60B and outer 62A, 62B forms a portion of the inner surface 34 of the toric cavity 36.

[0227] Each first and second continuous radially anchoring inner 60A, 60B and outer 602A, 62B band extends over at least 50% of the circumference of the tire 10 and here over the entire circumference of the tire 10.

[0228] Each first and second continuous circumferential sealing band radially inner 181, 182, radially outer 185, 186 and intermediate 183, 184 is disjoint from each other first and second continuous circumferential sealing band radially inner 181, 182, radially outer 185, 186 and intermediate 183, 184.

[0229] Each first and second continuous circumferential radial anchoring band, radially inner 60A, 60B and outer 62A, 62B, respectively comprises a first and second elastomeric composition distinct from the sealing composition. Here, the first and second elastomeric compositions are identical and are referred to as the elastomeric composition. The elastomeric composition is in contact with each first and second stiffening element 54A, 54B at each first and second radial anchoring point, radially inner 56A, 56B and outer 58A, 58B.

[0230] The elastomeric composition has a modulus at 10% extension of 8 MPa or less, preferably 5 MPa or less, and here equal to 3 MPa. Furthermore, the elastomeric composition comprises less than 50 parts per million of butyl rubber, preferably less than 10 parts per million of butyl rubber, and is more preferably here substantially free of butyl rubber. In addition, the elastomeric composition comprises at least 50 parts per million of a diene elastomer, for example, natural rubber. A person skilled in the art will have no difficulty formulating and manufacturing such a composition.

[0231] The second embodiment illustrated in [Fig. 3], in which the elements identical to those in the preceding figures bear the same reference numerals, differs from the first embodiment illustrated in Figures 1 and 2 in that the sealing layer 18 leaves a plurality of distinct radially internal 64A and external 66A first reservations remain. Each radially internal 64A first reservation is arranged so that the sealing layer 18 remains at a distance from each radially internal anchor point 56A. Each radially external 66A first reservation is arranged so that the sealing layer 18 remains at a distance from each radially external anchor point 58A.

[0232] Each first and second continuous circumferential sealing band radially inner 181, 182, radially outer 185, 186 and intermediate 183, 184 is joined respectively with each first and second continuous circumferential sealing band radially intermediate 183, 184, radially inner 181, 182 and outer 185, 186 and radially intermediate 183, 184.

[0233] Similarly, the sealing layer 18 leaves within the toroidal cavity a plurality of distinct radially internal and external second recesses. Each radially internal second recess is arranged so that the sealing layer remains at a distance from each radially internal anchor point of each second stiffening element of the plurality of second stiffening elements. Each radially external second recess of the plurality of radially external second recesses is arranged so that the sealing layer remains at a distance from each radially external anchor point of each second stiffening element of the plurality of second stiffening elements.

[0234] Each first and second radially inner and outer reservation comprises the elastomeric composition described above.

[0235] The third embodiment illustrated in Figures 4 and 5, in which the elements identical to those in the preceding figures bear the same reference numerals, differs from the first embodiment illustrated in Figures 1 and 2 in that the pneumatic 10 also includes first radially internal anchoring members 68A arranged in the toroidal cavity 36 and projecting from the first bead 32A into the interior of the toroidal cavity 12, being in contact at least locally with each first stiffening element 54A. The pneumatic 10 also includes first radially external anchoring members 70A arranged in the toroidal cavity 36 and projecting from the apex 12 into the interior of the toroidal cavity 36, being in contact at least locally with each first stiffening element 54A.

[0236] The tire 10 also includes second radially internal anchoring elements 68B arranged in the toroidal cavity 36 and projecting from the second bead 32B into the interior of the toroidal cavity 36, being in contact at least locally with each second stiffening element 54B. The pneumatic 10 also includes second radially external anchoring elements 70B arranged in the toroidal cavity 36 and extending in projection from the apex 12 into the interior of the toroidal cavity 36, being in contact at least locally with each second stiffening element 54B.

[0237] Each first and second radially internal anchoring member 68A, 68B is made of material with each first and second bead 32A, 32B respectively. Each first and second radially external anchoring member 70A, 70B is made of material with the apex 12. In addition, each first and second radially internal anchoring member 68A, 68B and external anchoring member 70A, 70B is made at least in part by the elastomeric composition described above.

[0238] Each first and second radially internal anchoring member 68A, 68B and external 70A, 70B has a stud shape.

[0239] It will obviously be possible to combine the separate reservations of the second embodiment described above with the anchoring elements of the third embodiment described above. Comparative tests

[0240] A test tire comprising a sealing layer arranged in contact with each anchor point of each stiffening element, as described in WO2022 / 200717, was tested. A tire according to the invention, identical to the tire according to the first embodiment but without a sealing layer, was also tested. These tests were carried out on a rolling machine simulating the stresses exerted by the Nürburgring circuit (Germany) on the tested tire under extreme racing conditions so as to cause degradation of the stiffening structure.

[0241] The test tire traveled 2 laps after which 20% of the stiffening elements showed a break in one of the radially inner anchoring portions (the one arranged on the outside of the vehicle) and 80% of the stiffening elements showed a dislodgement in one of the first and second beads (the one arranged on the outside of the vehicle).

[0242] The tire according to the invention also traveled 2 laps after which 90% of the stiffening elements showed a break in one of the radially inner anchoring portions (the one arranged on the outside of the vehicle) and 10% of the stiffening elements showed a dislodgement in one of the first and second beads (the one arranged on the outside of the vehicle).

[0243] Thus, the invention has made it possible to modify the majority failure mode of the stiffening structure by transferring the failure to the rupture of the stiffening elements which, apart from the loss of the advantages associated with the stiffening structure, entails no risk for the tire user, unlike a Failure due to dislodgement which can lead, in addition to the loss of the advantages associated with the stiffening structure, to a degradation of the tire structure, for example by an uncontrolled propagation of cracks at the point of dislodgement, and therefore a risk to the tire user.

Claims

Demands

1. A tire (10) comprising a top (12), first and second sidewalls (30A, 30B) each extending radially inwards from the top (12), first and second bead (32A, 32B) extending radially inwards respectively from the first and second sidewalls (30A, 30B), the tire (10) being provided with an internal surface (34) delimiting a toroidal cavity (36) for inflating the tire (10), the tire (10) comprising a rigidification structure (52) comprising at least one first rigidification element (54A) extending continuously in the toroidal cavity (36) from at least the first sidewall (30A) and / or bead (32A) to at least the top (12) and being anchored in the first sidewall (30A) and / or bead (32A) and / or the apex (12) extending into the first flank (30A) and / or bulge (32A) and / or the apex (12) from a first radially internal and / or external anchor point of the internal surface (34),the tire (10) comprising a sealing layer (18) for at least one inflation gas forming part of the internal surface (34), or the tire (10) being without a sealing layer (18) for at least one inflation gas forming part of the internal surface (34), tire wherein, in the case where the tire comprises a sealing layer (18) for at least one inflation gas forming part of the internal surface (34), the sealing layer (18) is arranged so as to remain at a distance from said first radially internal and / or external anchorage point (56A, 58A) of said first stiffening element (54A).

2. A tire (10) according to the preceding claim, wherein the stiffening structure (52) comprises at least one second stiffening element (54B) extending continuously into the toroidal cavity (36) from at least the second sidewall (30B) and / or bead (32B) to at least the apex (12) and being anchored in the second sidewall (30B) and / or bead (32B) and / or the apex (12) by extending into the second sidewall (30B) and / or bead (32B) and / or the apex (12) from a second radially internal and / or external anchorage point (56B, 58B) of the inner surface (34), in the case where the tire comprises a sealing layer (18) for at least one inflation gas forming part of the inner surface (34), the sealing layer (18) is arranged in such a way to stay away from said second radially internal and / or external anchoring point (56B, 58B) of said second stiffening element (54B).

3. Pneumatic (10) according to any one of the preceding claims, wherein at least a portion of said first stiffening element (54A) is coated with at least one layer of a polymeric composition, preferably an adhesive composition.

4. Pneumatic (10) according to the preceding claim, wherein said first stiffening element (54A) comprising a portion (543) extending continuously in the toroidal cavity (36) from said first radially internal anchor point (56A) of said first stiffening element (54A) to said first radially external anchor point (58A) of said first stiffening element (54A), said portion (543) extending continuously in the toroidal cavity (36) is coated at least in part with the polymeric composition.

5. Pneumatic (10) according to claim 3 or 4, wherein said first stiffening element (54A) comprising a radially inner anchoring portion (541) extending into the first flank (30A) and / or bead (32A) from said first radially inner anchoring point (54A), said radially inner anchoring portion (541) is coated at least in part with the polymeric composition.

6. Pneumatic (10) according to any one of claims 3 to 5, wherein said first stiffening element (54A) comprising a radially external anchoring portion (541) extending into the top (12) from said first radially external anchoring point (58A), said radially external anchoring portion (545) is coated at least in part with the polymeric composition.

7. Pneumatic (10) according to any one of the preceding claims, wherein the sealing layer (18) comprises a so-called sealing composition comprising one or more butyl rubbers.

8. Pneumatic (10) according to the preceding claim, wherein the first sidewall (30A) and / or bead (32A) and / or top (12) comprises a first elastomeric composition in contact with said first stiffening element (54A) at the first radially internal (56A) and / or external (58A) anchoring point.

9. Pneumatic (10) according to the preceding claim, wherein said first elastomeric composition comprises less than 50 parts per cent of ca- butyl rubber, preferably less than 10 pc of butyl rubber and is more preferably substantially free of butyl rubber.

10. Pneumatic (10) according to any one of the preceding claims, comprising a first anchoring member (68A, 70A) arranged in the toroidal cavity (36) and extending in projection from the first flank (30A) and / or bead (32A) into the interior of the toroidal cavity (36) and / or from the apex (12) into the interior of the toroidal cavity (36) being in contact at least locally with said first stiffening element (54A).

11. Pneumatic (10) according to any one of claims 1 to 10, wherein the stiffening structure (52) comprises a plurality of first stiffening elements (54A) distributed circumferentially in the toroidal cavity (36), the sealing layer (18) leaves within the toroidal cavity (36): - a first continuous circumferential band of radially inner anchorage (60A) arranged such that the sealing layer (18) remains at a distance from said first radially inner anchorage point (56A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A), and / or - a first continuous circumferential band of radially outer anchorage (62A) arranged such that the sealing layer (18) remains at a distance from said first radially outer anchorage point (58A) of each first stiffening element (54A) of the plurality of first elements of stiffening (54A).

12. Pneumatic (10) according to any one of claims 1 to 10, wherein the stiffening structure (52) comprising a plurality of first stiffening elements (54A), the sealing layer (18) leaves within the toroidal cavity (36): - a plurality of distinct radially internal first recesses (64A), each radially internal first recess (64A) of the plurality of radially internal first recesses (64A) being arranged so that the sealing layer (18) remains at a distance from said radially internal first anchor point (56A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A), and / or - a plurality of radially external first recesses distinct (66A), each first radially external reservation (66A) of the plurality of first radially external reservations (66A) is arranged so that the sealing layer (18) remains at a distance from said first radially external anchor point (58A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A).

13. Pneumatic (10) according to any one of the preceding claims, wherein, the stiffening structure (52) comprising a plurality of first stiffening elements (54A), the sealing layer (18) comprises: - a first continuous circumferential radially internal sealing strip (181) extending between a radially internal end of said first bead (32A) and said first radially internal anchor point (56A) of said first stiffening element (54A), remaining at a distance from said first radially internal anchor point (56A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A), and / or - a first continuous radially external sealing band (185) extending axially towards the second flank from said first radially external anchorage point (58A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A), remaining at a distance from said first radially external anchorage point (58A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A), and / or - a first continuous circumferential intermediate sealing strip (183) extending between said first radially internal anchorage point (56A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A) and said first radially external anchorage point (58A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A) remaining at a distance from said first radially internal anchorage point (56A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A) and at a distance from said first radially external anchorage point (58A) of each first stiffening element (54A) of the plurality of first stiffening elements (54A).

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