Pneumatic tire featuring a durable stiffening structure and high-performance internal radial anchoring

Abstract

The tire (10) includes sidewalls (30A, 30B), bead ribs (32A, 32B), an internal radial reinforcement structure (38A) arranged in a sidewall (30A) and / or bead (32A), a circumferential anchoring element (42A) extending in the sidewall (30A) and / or bead (32A) from an external radial end (421A) to an internal radial end (422A), a stiffening structure (52) including an internal radial anchor portion (541) extending in the sidewall (30A) and / or bead (32A) from an internal radial anchor point (56A) to anchor in or around an internal radial reinforcement structure (38A).The radially inner anchoring portion (541) extends from the radially inner reinforcing structure (38A) radially inwards outside a zone arranged radially between the radially outer (421A) and inner (422A) ends and axially between the circumferential anchoring element (42A) and a carcass layer (50). Figure for the abbreviation: Fig 1.

Description

Title of the invention: A pneumatic system comprising a durable stiffening structure and a high-performance internal radial anchoring 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. However, 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. Specifically, it was observed that the stiffening structure deteriorated due to the loosening of the stiffening elements in one of the first and second beads.

[0009] The invention aims to improve the endurance of the stiffening structure described in WO2020 / 128225 and to ensure the integrity of the tire even in the event 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 bead extensions respectively extending radially inwards from the first and second sidewalls, the tire being provided with an internal surface delimiting a toroidal inflation cavity of the tire, the tire having a substantially toroidal shape around an axis of revolution and comprising:

[0011] - at least one first radially internal reinforcing structure arranged in the first flank and / or ridge,

[0012] - a stiffening structure comprising at least one first stiffening element fication extending continuously in the toroidal cavity from at least the first flank and / or bead to at least the apex, and comprising at least one radially internal anchoring portion extending in the first flank and / or bead from a radially internal anchoring point of said first stiffening element to anchor in or around said first radially internal reinforcing structure,

[0013] - at least one first circumferential attachment element intended to allow the attachment of the tire to a mounting support, and extending in the first sidewall and / or bead radially inwards from a radially outer end to a radially inner end of said first circumferential attachment element, said radially inner anchoring portion of said first stiffening element extending, from said first radially inner reinforcing structure, radially inwards at least partly along said first circumferential attachment element, said first circumferential attachment element being axially adjacent to said radially inner anchoring portion,

[0014] - a carcass frame comprising at least one carcass layer arranged in less in the first flank and / or ridge and extending radially along said first circumferential attachment element, said first circumferential attachment element being axially adjacent to the carcass layer,

[0015] pneumatic in which said radially inner anchorage portion of said first stiffening element extends outside of an area located:

[0016] - axially between said carcass layer and said first circumferential element hanging, and

[0017] - radially between the radially outer end and the radially inner end exterior of said first circumferential attachment element.

[0018] 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.

[0019] 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 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.

[0020] 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 tire comprises:

[0021] - at least one second radially internal reinforcing structure arranged in the second flank and / or ridge,

[0022] - the stiffening structure comprising at least one second stiffening element fication extending continuously into the toroidal cavity from at least the second flank and / or bead to at least the apex, and comprising at least one radially internal anchoring portion extending into the second flank and / or bead from a radially internal anchoring point of said second stiffening element to anchor into or around said second radially internal reinforcing structure,

[0023] - at least one second circumferential attachment element intended to allow the attachment of the tire to a mounting support, and extending in the second sidewall and / or bead radially inwards from a radially outer end to a radially inner end of said second circumferential attachment element, said radially inner anchoring portion of said second stiffening element extending, from said second radially inner reinforcing structure, radially inwards at least in part along said second circumferential attachment element, said first circumferential attachment element being axially adjacent to said radially inner anchoring portion,

[0024] - said carcass layer being arranged at least in the second flank and / or bead and extending radially along said second circumferential attachment element, said second circumferential attachment element being axially adjacent to the carcass layer,

[0025] pneumatic in which said radially inner anchorage portion of said second stiffening element extends outside of an area located:

[0026] - axially between said carcass layer and said second circumferential element hanging, and

[0027] - radially between the radially outer end and the radially inner end exterior of said second circumferential attachment element.

[0028] The stiffening element concerned exerts high forces on the corresponding flank and / or bead which are absorbed by said radially reinforcing structure. corresponding outer edge. These high stresses are the cause, in the prior art tire described in WO2022 / 200717, of crack initiation at the anchor point in the sidewall and / or bead. When the innermost radial point of the relevant stiffening element is arranged radially outside the outermost radial end of the circumferential anchoring element, or even worse, when the innermost radial point of the relevant stiffening element is arranged axially between the carcass layer and the circumferential anchoring element, cracks can propagate in the area located axially between the carcass layer and the corresponding circumferential anchoring element, and radially between the outermost and innermost radial ends of the relevant circumferential anchoring element, leading to separation of the circumferential anchoring element.

[0029] Positioning the radially inner anchoring portion concerned according to the invention at least in part along the circumferential hooking element, that is to say radially inside the radially outer end of the circumferential hooking element while remaining outside the zone located axially between the carcass layer and the circumferential hooking element and located radially between the radially outer end and the radially inner end of the circumferential hooking element, makes it possible to ensure the integrity of the tire even if there were an initiation and propagation of cracks which nevertheless engendered the loss of the advantages associated with the stiffening structure.On the contrary, a crack initiated in said area 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 leading to a separation of the circumferential gripping element.

[0030] Thus, an anchorage according to the invention is significantly more robust than the bead interfaces described in WO2020 / 128225 and ensures the integrity of the tire compared to WO2022 / 200717.

[0031] The radially outer end of the circumferential attachment element corresponds to the point of said circumferential attachment element located most radially on the outside. Similarly, the radially inner end of the circumferential attachment element corresponds to the point of said circumferential attachment element located most radially on the inside.

[0032] The carcass frame may comprise several carcass layers. The invention may therefore preferably be applied to each carcass layer of the carcass frame.

[0033] A circumferential attachment element is axially adjacent to the carcass layer, meaning that the circumferential attachment element is the circum The axially closest ferrule to the carcass layer when moving axially inwards or outwards from the carcass layer. Thus, a carcass layer can have a single circumferential anchoring element axially inside or axially outside, or two circumferential anchoring elements axially inside and axially outside.

[0034] A circumferential hooking element is axially adjacent to the radially inner anchoring portion means that the circumferential hooking element is the circumferential element axially closest to the radially inner anchoring portion.

[0035] In some cases, the circumferential attachment element is in contact with the carcass layer such that the area located axially between the carcass layer and the circumferential attachment element and located radially between the radially outer end and the radially inner end of the circumferential attachment element has a thickness substantially zero over all or part of the length of the circumferential attachment element.In other, more preferred cases, the circumferential attachment element is at a distance from the carcass layer such that the area axially between the carcass layer and the circumferential attachment element and radially between the outer radial end and the inner radial end of the circumferential attachment element has a non-zero thickness, preferably less than or equal to 1 mm and for example equal to 0.5 mm, so as to ensure mechanical decoupling between the carcass layer and the circumferential attachment element.

[0036] In some cases, the radially inner anchorage portion extends along the circumferential anchoring element in contact with the circumferential anchoring element. In other preferred cases, the radially inner anchorage portion extends along the circumferential anchoring element at a distance from the circumferential anchoring element, preferably at a distance less than or equal to 1 mm and for example equal to 0.5 mm, so as to reduce as much as possible the risk of propagation of a possible crack initiation from the radially inner anchorage portion axially through the circumferential anchoring element.

[0037] The radially internal reinforcement structure, arranged radially outside the corresponding circumferential mounting element, reduces the propagation of noise generated by the stiffening structure from the stiffening structure to the vehicle through the tire mounting support. This is because the noise generated by the stiffening structure is dampened by the tire structure separating the radially internal reinforcement structure from the circumferential mounting element located on the same side of the tire's median plane.

[0038] This damping is the result of the fact that the radially inwardly reinforcing structure the outer part considered is mechanically decoupled from the circumferential attachment element located on the same side of the median plane of the tire.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The presence of the stiffening structure thus makes it possible to reduce the contribution of the tire to load-bearing capacity and therefore to reduce its structural rigidity, for example by reducing the volume of the beads. Indeed, the beads of a conventional tire dissipate a significant amount of energy, due to their volume and the hysteretic nature of their constituent elastomeric compound. Reducing their volume thus makes it possible to significantly reduce resistance to bearing.

[0045] 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.

[0046] 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.

[0047] 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).

[0048] 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.

[0049] By median plane of the tire, denoted 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.

[0050] 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.

[0051] By meridian plane, we mean a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0052] 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.

[0053] 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 hook on the rim enabling its attachment. The bead is thus delimited radially internally by the inner radial 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 standard. and Rim Technical Organisation ou « ETRTO », 2023.

[0054] 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.

[0055] 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., bounds a and b excluded) 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).

[0056] 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.

[0057] 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 12 inches and at most 30 inches.

[0058] Optionally, the first circumferential attachment element is arranged radially inside said first radially inner reinforcement structure by being wrapped circumferentially around the axis of revolution.

[0059] Optionally, the second circumferential attachment element is arranged radially inside said second radially inner reinforcement structure by being wrapped circumferentially around the axis of revolution.

[0060] Optionally, said first circumferential attachment element is wound circumferentially over at least two full turns, preferably over at least three full turns, more preferably over at least four full turns, even more preferably over at least five full turns and very preferably over at least six full turns, around the axis of revolution.

[0061] Optionally, said second circumferential attachment element is wound circumferentially over at least two full turns, preferably over at least three full turns, more preferably over at least four full turns, even more preferably over at least five full turns and very preferably over at least six full turns, around the axis of revolution.

[0062] In one embodiment, said first and / or second circumferential attachment element is a wire reinforcement element 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.

[0063] The first radially internal reinforcement structure arranged in the first flank and / or bead preferably includes at least one first circumferential radially internal reinforcement element allowing the anchoring of the stiffening structure.

[0064] In embodiments comprising a second radially internal reinforcement structure arranged in the second side and / or bead, this preferably includes at least one second circumferential radially internal reinforcement element allowing the anchoring of the stiffening structure.

[0065] In one embodiment, the first and / or second radially internal reinforcement structure comprises at least one wire reinforcement element 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.

[0066] In a particular embodiment, the first and / or second radially internal reinforcement structure comprises at least two separate wire reinforcement elements.

[0067] By distinct, it is understood that the two wire reinforcement elements are discontinuous with respect to each other.

[0068] Advantageously, the wire reinforcement element or each wire reinforcement element of the first and / or second radially internal reinforcement structure is circumferentially wound over at least one full turn around the axis of revolution.

[0069] Advantageously, said first stiffening element penetrates the top at a first radially external anchorage point of said first stiffening element.

[0070] Optionally, said second stiffening element penetrates the top at a second radially external anchor point of said second stiffening element.

[0071] Advantageously, said first stiffening element comprises a portion extending continuously in the toroidal cavity from the first radially internal anchor point to the first radially external anchor point.

[0072] Advantageously, said first stiffening element comprises a radially external anchoring portion extending from the first radially external anchoring point in the apex and extending the portion extending continuously in the toric cavity.

[0073] Optionally, said second stiffening element comprises a portion extending continuously in the toroidal cavity from the second radially inner anchor point to the second radially outer anchor point.

[0074] Optionally, said second stiffening element includes a radially external anchoring portion extending from the second radially external anchoring point in the apex and extending the portion extending continuously into the toroidal cavity.

[0075] Advantageously, said radially external anchoring portion of said first stiffening element is anchored in the top by being anchored in or around one or more radially external reinforcing structures of the stiffening structure arranged in the top.

[0076] Alternatively, said radially external anchoring portion of said first stiffening element is anchored in the apex by being anchored in an elastomeric mass of said apex.

[0077] Optionally, said radially external anchoring portion of said second stiffening element is anchored in the top by being anchored in or around one or more radially external reinforcing structures of the stiffening structure arranged in the top.

[0078] Alternatively, said radially external anchoring portion of said second stiffening element is anchored in the apex by being anchored in an elastomeric mass of said apex.

[0079] Each radially internal or external reinforcing structure is respectively arranged in the corresponding side and / or bead or in the top, that is, arranged radially within the internal surface and embedded in the mass of materials constituting the corresponding side and / or bead or the top. The stiffening structure passes through the internal surface to be anchored in or around the corresponding radially internal reinforcement structure and / or through the internal surface to anchor in or around the radially external reinforcement structure(s).

[0080] As previously stated, the stiffening structure can be anchored in or around at least one radially internal and / or external reinforcing structure.

[0081] 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.

[0082] In particular, in the case 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.

[0083] 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.

[0084] 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.

[0085] In embodiments comprising at least one radially external reinforcing structure arranged in the apex, this preferably comprises at least one circumferential radially external reinforcing element.

[0086] In one embodiment, said radially external circumferential reinforcement element of the or each radially external reinforcement structure is a wire reinforcement element 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] Thus, the axial distribution of the forces exerted by the stiffening structure on the summit is improved.

[0091] In other embodiments, the tire comprises a single radially external reinforcement structure extending continuously on each side of the tire's median plane. 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 comprises at least one crown layer including reinforcing elements. These reinforcing elements are preferably textile or metallic wire elements.

[0092] 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.

[0093] 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.

[0094] In advantageous embodiments, said radially inner anchoring portion of said first stiffening element extends radially inwards to a point arranged radially inside the radially outer end of said first circumferential attachment element.

[0095] In embodiments using a second stiffening element, said radially inner anchoring portion of said second stiffening element extends radially inwards to a point arranged radially inside the radially outer end of said second circumferential attachment element.

[0096] Thus, the relevant anchoring portion extends radially relatively deep into the corresponding flank and / or bulge, which improves the endurance of the anchoring of the stiffening structure.

[0097] In one variant, said radially inner anchoring portion of said first stiffening element extends radially inwards to a point arranged radially outside the radially inner end of said first circumferential hooking element.

[0098] In embodiments using a second stiffening element, said radially inner anchoring portion of said second stiffening element extends radially inwards to a point arranged radially outside the radially inner end of said second circumferential attachment element.

[0099] In this variant, the amount of the stiffening portion extending radially inwards is optimized. Furthermore, the risk of compromising the integrity of the tire is further delayed due to the relatively large radial height of material within the radially inner anchoring portion that must be traversed in the event of crack initiation.

[0100] In another variant, said radially inner anchoring portion of said first stiffening element extends radially inwards to a point arranged radially inside the radially inner end of said first circumferential hooking element.

[0101] In embodiments using a second stiffening element, said radially inner anchoring portion of said second stiffening element extends radially inwards to a point arranged radially inside the radially inner end of said second circumferential anchoring element.

[0102] Optionally, said radially inner anchorage portion of said first stiffening element extends radially inwards at least from the radially outer end of said first circumferential anchoring element for at least 10%, preferably at least 20% of a length of said first circumferential anchoring element.

[0103] In embodiments using a second stiffening element, said radially inner anchorage portion of said second stiffening element extends radially inwards at least from the radially outer end of said second circumferential attachment element for at least 10%, preferably at least 20% of a length of said second circumferential attachment element.

[0104] Thus, the anchoring portion has a relatively large length to improve the endurance of the stiffening structure's anchorage. Indeed, a length that is too short of the radially inner anchoring portion from the radially outer end of the first circumferential element would make the stiffening structure's anchorage susceptible to dislodging under high stresses.

[0105] The length of the circumferential attachment element is taken between the radially outer and inner ends and is the distance of the straight segment joining the radially outer and inner ends of said circumferential attachment element.

[0106] The length of the radially inner anchorage portion from the radially outer end of the corresponding circumferential hooking element is the distance of the straight segment joining the point of the radially inner anchorage portion to the radially outer end of the circumferential hooking element and the most radially inner point of the radially inner anchorage portion.

[0107] Thus, the ratio between the length of the radially inner anchoring portion and the length of the circumferential hooking element corresponds to the overlap length ratio of these two lengths.

[0108] Optionally, said radially inner anchorage portion of said first stiffening element comprises at least first and second branches, said first branch extending radially inwards and axially outwards from the radially inner anchorage point of said first stiffening element, said second branch extending radially inwards and axially inwards from said first branch or from a third branch of said first stiffening element connecting said first branch and said second branch.

[0109] In embodiments using a second stiffening element, said radially inner anchorage portion of said second stiffening element comprises at least first and second branches, said first branch extending radially inwards and axially outwards from the radially inner anchorage point of said second stiffening element, said second branch extending radially inwards and axially inwards from said first branch or from a third branch of said second stiffening element connecting said first branch and said second branch.

[0110] The first and second branches arranged in this way make it possible to create a robust anchorage of the anchor portion due to the change in the direction in which the anchor portion extends in the axial direction.

[0111] In advantageous embodiments, the second branch extends radially at least partially along said first circumferential attachment element. Thus, the second branch extends radially at least partially inside the radially outer end of said first circumferential attachment element.

[0112] In embodiments using a second stiffening element, the second branch extends radially at least partially along said second circumferential attachment element. Thus, the second branch extends radially at least partially inside the radially outer end of said second circumferential attachment element.

[0113] Thus, the second branch participates in the anchoring of the concerned stiffening element, and all the more so as it extends radially inside the radially external end of the circumferential attachment element adjacent to said radially internal anchoring portion concerned.

[0114] In a preferred configuration, said radially inner anchorage portion of said first stiffening element extends radially inwards at least in part along said first circumferential hooking element without being anchored in the first circumferential hooking element.

[0115] In a preferred configuration, said radially inner anchorage portion of said second stiffening element extends radially inwards at least in part along said second circumferential hooking element without being anchored in the second circumferential hooking element.

[0116] Thus, the risk that significant stresses exerted on the stiffening element will cause separation of the circumferential attachment element is further reduced.

[0117] In another configuration, said radially inner anchorage portion of said first stiffening element extends radially inwards at least in part along said first circumferential hooking element by being anchored in or around said first circumferential hooking element.

[0118] In embodiments using a second stiffening element, said radially inner anchorage portion of said second stiffening element extends radially inwards at least in part along said second circumferential attachment element by being anchored in or around said second circumferential attachment element.

[0119] Optionally, the tire includes a first circumferential internal axial attachment element and a first circumferential attachment element axially external intended to enable the tire to be attached to a mounting support, and arranged radially inside said first radially internal reinforcement structure, each first circumferential internal and external axially external attachment element being axially adjacent to the carcass layer and extending in the first sidewall and / or bead radially inwards from a radially external end to a radially internal end respectively of said first circumferential internal and external axially external attachment element, said carcass layer extending radially along each first circumferential internal and external axially external attachment element and axially between said first circumferential internal axially external attachment element and said first circumferential external axially external attachment element.

[0120] Thus, the carcass layer is anchored in the first flank and / or bead between said first circumferential internal axial anchoring element and said first circumferential external anchoring element.

[0121] Optionally, the tire includes a second circumferential internal axially anchoring element and a second circumferential external axially anchoring element intended to allow the tire to be attached to a mounting support, and arranged radially inside said second internal radially reinforcing structure, each second internal and external axially anchoring element being axially adjacent to the carcass layer and extending in the second sidewall and / or bead radially inwards from an external radial end to an internal radial end respectively of said second internal and external axially anchoring element,said carcass layer extending radially along each second internal and external axially circumferential anchoring element and axially between said second internal axially circumferential anchoring element and said second external axially circumferential anchoring element.

[0122] Thus, the carcass layer is anchored in the second flank and / or bead between said second circumferential axially internal anchoring element and said second circumferential axially external anchoring element.

[0123] In one configuration, said radially inner anchorage portion of said first stiffening element extends at least partially axially inside said first circumferential axially inner attachment element.

[0124] In embodiments using a second stiffening element, said radially inner anchorage portion of said second stiffening element extends at least partially axially inside said second circumferential axially inner anchoring element.

[0125] In this configuration, the tire manufacturing process is simplified by keeping the radially inner axial anchoring portion inside the carcass layer.

[0126] In this configuration, the optional and advantageous characteristics previously described with reference to the first and / or second circumferential attachment element can optionally and advantageously be applied to the first and / or second axially internal circumferential attachment element.

[0127] In another configuration, said radially inner anchoring portion of said first stiffening element traverses axially said carcass layer and extends at least partially axially outside said first circumferential axially outer attachment element.

[0128] In embodiments using a second stiffening element, said radially inner anchoring portion of said second stiffening element axially traverses said carcass layer and extends at least partially axially outside said second circumferential axially outer anchoring element.

[0129] In this other configuration, the tire manufacturing process is made more complex by moving the radially inner axial anchoring portion outside the carcass layer, but the anchoring of this radially inner anchoring portion is made more robust by increasing its length.

[0130] In this other configuration, the optional and advantageous characteristics previously described with reference to the first and / or second circumferential attachment element can optionally and advantageously be applied to the first and / or second axially external circumferential attachment element.

[0131] In optional embodiments, said first radially internal reinforcement structure comprises a first circumferential radially internal reinforcement element distinct from the first circumferential attachment element.

[0132] Preferably, in configurations using first axially internal and external circumferential attachment elements, the first radially internal circumferential reinforcement element of said first radially internal reinforcement structure is distinct from each first axially internal and external circumferential attachment element.

[0133] In embodiments using a second stiffening element, said second radially internal reinforcement structure comprises a second circumferential radially internal reinforcement element distinct from the second circumferential attachment element.

[0134] Preferably, in configurations using second circumferential attachment elements axially internal and external, the second circumferential element The radially internal reinforcement element of said second radially internal reinforcement structure is distinct from each second circumferential internal and external axially external attachment element.

[0135] Thus, the anchoring of the stiffening structure is mechanically decoupled from the attachment of the tire to its mounting support.

[0136] By distinct, it is understood that the circumferential elements are discontinuous with respect to each other or to each other.

[0137] 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.

[0138] Optionally, said second radially internal anchor point of said second stiffening element and said second radially external anchor point of said second stiffening element are arranged on the same other side of the median plane of the tire.

[0139] Thus, the portions extending, on the one hand, between an inner radial anchor point and an outer radial anchor point located on the same side of the median plane, and on the other hand, between an inner radial anchor point and an outer radial anchor point located on the opposite side of the median plane, do not intersect. This limits the axial buckling of the tread, i.e., the axial compression of the tread, particularly under conditions of high lateral stress. In this way, on the one hand, a regular contact area is maintained, and on the other hand, the risk of damage to the crown reinforcement of the tire is reduced, notably by preventing compression of the various constituent elements of the crown reinforcement, for example, the textile and metallic wire reinforcement elements of the crown reinforcement.

[0140] Preferably, the stiffening structure comprises a plurality of first stiffening elements distributed circumferentially in the toric cavity.

[0141] Optionally, the stiffening structure includes a plurality of second stiffening elements distributed circumferentially in the toric cavity.

[0142] 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.

[0143] Thus, the manufacture of the tire is facilitated and the robustness of the stiffening structure is improved by removing the ends of said stiffening element to be anchored in each sidewall and / or bead and / or in the crown. In this first configuration, it is possible to have a continuous stiffening element extending around the entire circumference of the tire. Because this stiffening element of the stiffening structure 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] Each stiffening element according to one of the designs or configurations defined above can be characterized geometrically, in particular by its average cross-section Sm, this characteristic not necessarily being identical for The entire set of stiffening elements. The average cross-sectional area Sm is the average of the cross-sections 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.

[0150] 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.

[0151] A second type of stiffening element, with an 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 of at least 3 and at most 50 is called a two-dimensional strap-type element. According to a second variant, a stiffening element, with a form ratio R at least equal to 50, is said to be two-dimensional of film type.

[0152] The materials that can be used for each stiffening element are as described in WO2022 / 200717.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Advantageously, in an embodiment for manufacturing the tire using a relatively simple process, each wire stiffening element extends within the toroidal cavity along a principal direction forming an angle with the circumferential direction of the tire ranging, in absolute value, from 85° to 90°. In another embodiment for manufacturing the tire using a more complex process but allowing for increased circumferential stiffness, each wire stiffening element extends within the toroidal cavity along a principal direction forming an angle with the circumferential direction of the tire ranging, in absolute value, from 45° to 85°, as explained in particular in WO2020 / 128225. Brief description of the drawings

[0157] 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 attached drawings, on which:

[0158] [Fig-1] is a view of a tire in a meridian cutting plane parallel to the axis of rotation according to a first example of an embodiment of the invention;

[0159] [Fig.2] and [Fig.3] are schematic representations of the arrangement of the stiffening structure of the [Fig. 1] in each first and second flank and / or bead; and

[0160] [Fig.4], [Fig.5], [Fig.6], [Fig.7], [Fig.8], [Fig.9], [Fig.10] and [Fig.11] are views analogous to that of [Fig.2] of tires respectively according to second, third, fourth, fifth, sixth, seventh, eighth and ninth examples of embodiment of the invention. Detailed description

[0161] In the figures relating to the tire, a reference frame X, Y, Z has been represented corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0162] 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.

[0163] The tire 10 according to the first embodiment described with reference to Figures 1 to 3 comprises a vertex 12 including a tread 14 intended to come into contact with a ground during rolling and a vertex reinforcement 16 extending into the vertex 12 in the circumferential direction X. The tire 10 also comprises an inner layer 18.

[0164] 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.

[0165] 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 each first and second sidewall 30A, 30B radially inward, 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 to the apex 12, respectively. The tire 10 is provided with a internal surface 34, intended to be in contact with the tire inflation gas, and which delimits a toroidal cavity 36 for tire inflation 10. The internal surface 34 is here supported by the inner layer 18.

[0166] The tire 10 includes first and second radially internal reinforcement structures 3 8A, 38B respectively arranged in each first and second bead 32A, 32B.

[0167] Each first and second radially internal reinforcing structure 38A, 38B respectively comprises at least first and second circumferential radially internal reinforcing elements 40A, 40B, respectively arranged in each first and second bead 32A, 32B, including in particular at least first and second wire reinforcing elements as described in WO2022 / 200717.

[0168] Each first and second bead 32A, 32B respectively comprises a first and second axially internal circumferential attachment element 42A, 42B and a first and second axially external circumferential attachment element 43A, 43B, here each comprising a bead, and intended to allow the tire 10 to be attached to a tire mounting support 10, for example a rim. Each first and second axially internal circumferential attachment element 42A, 42B is arranged respectively inside each first and second axially external circumferential attachment element 43A, 43B. Each first axially internal circumferential attachment element 42A is distinct from each first axially external circumferential attachment element 43A. Each second internal axially circumferential hooking element 42B is distinct from each second external axially circumferential hooking element 43B.

[0169] The first axially internal circumferential attachment element 42A comprises a radially external end 421A and a radially internal end 422A defining a length L1 of the first axially internal circumferential attachment element 42A. The first axially external circumferential attachment element 43A comprises a radially external end 431A and a radially internal end 432A defining a length L1' of the first axially external circumferential attachment element 43A.

[0170] The second axially internal circumferential attachment element 42B comprises a radially external end 421B and a radially internal end 422B defining a length L2 of the second axially internal circumferential attachment element 42B. The second axially external circumferential attachment element 43B comprises a radially external end 431B and a radially internal end 432B defining a length L2' of the second axially external circumferential attachment element 43B.

[0171] Each length Ll, Ll', L2, L2' ranges from 3 to 20 mm.

[0172] Each first and second axially internal circumferential gripping element 42A, 42B and axially external 43A, 43B is circumferentially wound by at least two full turns, preferably by at least three full turns, more preferably by at least four full turns, even more preferably by at least five full turns and very preferably by at least six full turns around the axis of revolution of the tire 10, and here by eight full turns for the first and second axially internal circumferential gripping elements 42A, 42B and by seven full turns for the first and second axially external circumferential gripping elements 43A, 43B, so as to extend respectively in the first or second bead 32A, 32B radially inwards from the radially external end 421A, 421B, 431A, 43IB corresponding up to the radially inner end 422A, 422B, 432A,432B corresponding. ,

[0173] Each first and second circumferential internal axially 42A, 42B and externally axially 43A, 43B attachment element is arranged radially inside each first and second radially internal reinforcement structure 38A, 38B respectively, in particular each first and second circumferential internal axially 42A, 42B and externally axially 43A, 43B attachment element is arranged radially inside each first and second circumferential radially internal reinforcement element 40A, 40B respectively.Each first and second radially internal reinforcement structure 3 8A, 38B is arranged respectively radially outwards with respect to the radially external end 421 A, 421B of each first and second axially internal circumferential anchoring element 42A, 42B and with respect to the radially external end 43 IA, 431B of each first and second axially external circumferential anchoring element 43A, 43B. .

[0174] Each first internal radially reinforcing circumferential element 40A is distinct from each first internal axially reinforcing circumferential element 42A and external axially reinforcing circumferential element 43A. Each second internal radially reinforcing circumferential element 40B is distinct from each second internal axially reinforcing circumferential element 42B and external axially reinforcing circumferential element 43B.

[0175] 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 reinforcement element ra- external dialement 46A, 46B is as described in WO2022 / 200717.

[0176] The tire 10 comprises a carcass reinforcement 48 including a carcass layer 50 extending axially in the crown 12 radially inwardly to the crown reinforcement 16 and radially in each first and second sidewall 30A, 30B and bead 32A, 32B. The crown reinforcement 16 is arranged radially between the tread 14 and the carcass reinforcement 48. The various crown layers 24, 26, 28 and carcass 50 are identical to those described in WO2022 / 200717.

[0177] The carcass layer 50 is therefore arranged in each first and second flank 30A, 30B and bead 32A, 32B and anchored in each first and second bead 32A, 32B.

[0178] In this case, the carcass layer 50 extends axially between each first and second axially internal circumferential anchoring element 42A, 42B and each first and second axially external circumferential anchoring element 43A, 43B. Each first and second axially internal circumferential anchoring element 42A, 42B and axially external circumferential anchoring element 43A, 43B is axially adjacent to the carcass layer 50 respectively in each first and second bead 32A, 32B.

[0179] The carcass layer 50 extends radially along each first and second circumferential axially internal 42A, 42B and external 43A, 43B attachment element.

[0180] 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 toric cavity 36 from the first bead 32A and from the second bead 32B to the apex 12 and is anchored in the apex 12 by being anchored around the radially external reinforcing structures 44A, 44B.

[0181] 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.

[0182] Each stiffening element 54 is a textile wire stiffening element comprising an assembly of three multifilament strands of aliphatic polyamide, for example nylon, these three multifilament strands being individually 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 count of 188 tex.

[0183] 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.

[0184] 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 high extension and bending stiffnesses.

[0185] 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.

[0186] Each first stiffening element 54A is anchored, in the first bead 32A, in or around the first radially internal reinforcing structure 38A. Each second stiffening element 54B is anchored in the second bead 32B, in or around the second radially internal reinforcing structure 38B.

[0187] 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.

[0188] 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 reinforcing structure 38A and at a first radially external anchor point 58A in the apex 12 to anchor around the first radially external reinforcing structure 44A. Thus, each first stiffening element 54A is anchored in the first bead 32A extending into the first bead 32A from the first radially internal anchor point 56A. Each first stiffening element 54A is anchored into the top 12 extending into the top 12 from the first radially external anchor point 58A.

[0189] 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 vertex 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 vertex 12 by extending into the vertex 12 from the second radially external anchor point 58B.

[0190] 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.

[0191] Each second stiffening element 54B comprises an internal radial anchorage portion 542, a portion 544, and an external radial anchorage portion 546, the portion 544 being extended on one side by the internal radial anchorage portion 542 and on the other side by the external radial anchorage portion 546.

[0192] 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.

[0193] The portion 544 of each second stiffening element 54B extends in the toric cavity 36 from the second radially internal anchor point 56B to the second radially external anchor point 58B.

[0194] 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 in or around the first radially internal reinforcing structure 38A.

[0195] 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.

[0196] 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 in or around the second radially internal reinforcing structure 38B.

[0197] The radially external anchorage portion 546 of each second ri-gidification element 54B extends from the second radially external anchorage point 58B in the vertex 12 to anchor around the second radially external reinforcement structure 44B.

[0198] Each first stiffening element 54A forms a first continuous stiffening element which meanders at least 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 54 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.

[0199] The radially inner anchoring portion 541 of each first stiffening element 54A extends, from the first radially inner reinforcing structure 38A, radially inwards at least partly along the first axially inner circumferential anchoring element 42A axially adjacent to the radially inner anchoring portion 541, outside a first zone 49A located axially between the carcass layer 50 and the first axially inner circumferential anchoring element 42A and located radially between the radially outer end 421A and the radially inner end 422A of the first axially inner circumferential anchoring element 42A.The radially internal anchoring portion 541 extends radially inwards at least partly along the first axially internal circumferential anchoring element 42A without being anchored in the first axially internal circumferential anchoring element 42A.

[0200] The radially inner anchorage portion 542 of each second stiffening element 54B extends, from the second radially inner reinforcement structure 38B, radially inward at least partially along the second axially inner circumferential anchoring element 42B axially adjacent to the radially inner anchorage portion 542, outside a second zone 49B located axially between the carcass layer 50 and the second axially inner circumferential anchoring element 42B and located radially between the radially outer end 421B and the radially inner end 422B of the second circumferential internal axial anchoring element 42B. The radially internal anchoring portion 542 extends radially inwards at least partly along the second circumferential internal axial anchoring element 42B without being anchored in the second circumferential internal axial anchoring element 42B.

[0201] The first radially external anchor point 58A is arranged axially from the The first radially internal anchor point 56A and the first radially internal reinforcement structure 38A are arranged axially on the same side as the first radially internal anchor point 56A and the first radially internal reinforcement structure 38A with respect to the median plane M. The second radially external anchor point 58B is arranged axially on the same side as the second radially internal anchor point 56B and the second radially internal reinforcement 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 portions 543, 544 do not intersect in the toric cavity 36.

[0202] Each first and second stiffening element 54A, 54B is partially wound respectively around each first and second internal radially internal circumferential reinforcing element 40A, 40B, each first and second internal radially internal circumferential reinforcing element 40A, 40B being respectively the unique internal radially internal circumferential reinforcing element of each corresponding first and second internal radially internal reinforcing structure 38A, 38B and being circumferentially wound around a complete turn around the axis of revolution.

[0203] More specifically and with reference to Figures 2 and 3, each radially internal anchorage portion 541 and 542 of each first and second stiffening element 54A and 54B comprises first, second and third branches 5411, 5412, 5413 and 5421, 5422, 5423 arranged successively respectively in each first and second bead 32A and 32B.

[0204] Each first branch 5411, 5421 extends radially inwards and axially outwards from each first and second radially internal anchorage point 56A, 56B, each first branch 5411, 5421 being substantially straight here. Each second branch 5412, 5422, which is substantially straight here, extends radially and axially inwards respectively from each third branch 5413, 5423 which connects each first branch 5411, 5421 and each second branch 5412, 5422. Each third branch 5413, 5423 is partially wrapped around the first and second circumferential radially internal reinforcing element 40A, 40B and is therefore curved here.

[0205] Each second branch 5412, 5422 extends radially at least partially along each first and second axially internal circumferential attachment element 42A, 42B. More precisely, each second branch 5412, 5422 extends radially- diamentally at least partly inside each radially external end 421 A, 421B of each first and second axially internal circumferential hooking element 42A, 42B.

[0206] Each radially internal anchorage portion 541, 542 extends at least partially axially inside each first and second circumferential axially internal anchoring element 42A, 42B.

[0207] Each radially internal anchor portion 541, 542 extends radially inwards to a point arranged radially inside the radially external end 421 A, 421B of each first and second axially internal circumferential hooking element 42A, 42B.

[0208] Each radially inner anchor portion 541, 542 extends radially inward to a point arranged radially outside the radially inner end 422A, 422B of each first and second circumferential hooking element 42A, 42B.

[0209] We will now describe other embodiments with reference to Figures 4 to 12, in which elements analogous to those of the first embodiment are designated by identical reference numerals. In the examples described with reference to Figures 4 to 12, the radially internal anchoring portion 542 of each second stiffening element 54B is defined mutatis mutandis with respect to the radially internal anchoring portion 541 of each first stiffening element 54A.

[0210] The second embodiment illustrated in [Fig.4] differs from the first embodiment in that the radially internal anchoring portion 541 of each first stiffening element 54A is anchored in the first main radially internal reinforcing circumferential element 42A.

[0211] The third embodiment illustrated in [Fig. 5] differs from the first embodiment in that the first radially internal reinforcement structure 38A comprises a first circumferential radially internal reinforcement element 40A wound circumferentially in two complete turns around the axis of revolution superimposed in the radial direction. The first radially internal reinforcement structure 38A also comprises a first complementary radially internal reinforcement element 40A' distinct from the first circumferential radially internal reinforcement element 40A. The first complementary radially internal reinforcement element 40A' is wound circumferentially in one complete turn around the axis of revolution.The radially internal anchorage portion 541 extends at least in part between the first circumferential radially internal reinforcement element 40A and the first circumferential complementary radially internal reinforcement element 40A'.

[0212] The fourth embodiment illustrated in [Fig. 6] differs from the first embodiment of embodiment in that the first radially internal reinforcing structure 38A comprises a first circumferential radially internal reinforcing element 40A wound circumferentially in three complete turns around the axis of revolution arranged side by side along the axial direction. The first radially internal reinforcing structure 38A also comprises a first complementary circumferential radially internal reinforcing element 40A' analogous to that of the third embodiment.

[0213] The fifth embodiment illustrated in [Fig. 7] differs from the first embodiment in that the radially internal anchoring portion 541 of each first stiffening element 54A extends radially inwards at least 10%, preferably at least 20%, of the length L1 of the first axially internal circumferential anchoring element 42A from the radially internal end 421A. In this case, L1 = 15 mm and the length of the radially internal anchoring portion 541 from the radially external end 421A is here substantially equal to 8 mm.

[0214] The sixth embodiment illustrated in [Fig.8] differs from the fifth embodiment illustrated in [Fig.7] in that the radially internal anchoring portion 541 extends radially inwards to a point arranged radially inside the radially internal end 422A of the first axially internal circumferential anchoring element 42A.

[0215] The seventh embodiment illustrated in [Fig.9] differs from the first embodiment in that the first bead 32A further comprises a first additional radially internal reinforcing circumferential element 60A offset axially inwards relative to the first axially internal hooking circumferential element 42A, and here wound circumferentially over four full turns around the axis of revolution so that the first additional radially internal reinforcing circumferential element 60A extends in the first bead 32A radially inwards and axially inwards.

[0216] The radially internal anchoring portion 541 of each first stiffening element 54A is arranged axially in part between the first axially internal anchoring circumferential element 42A and the first additional radially internal reinforcing circumferential element 60A.

[0217] The eighth embodiment illustrated in [Fig. 10] differs from the fifth embodiment illustrated in [Fig. 7] in that the radially internal anchoring portion 541 traverses axially through the carcass layer 50 to anchor around the first circumferential radially internal reinforcing element 40A arranged axially outside the carcass layer 50. The radially anchoring portion interior 541 extends at least partly axially outside the first circumferential external axially attached element 43A.

[0218] In this eighth embodiment, the first axially external circumferential anchoring element 43A is axially adjacent to the radially internal anchoring portion 541 so that the radially internal anchoring portion 541 extends, from the first radially internal reinforcing structure 38A, radially inwards at least partly along the first axially external circumferential anchoring element 43A.

[0219] In this eighth embodiment, the radially internal anchoring portion 541 extends outside the first zone 49A' located axially between the carcass layer 50 and the first axially external circumferential anchoring element 43A and located radially between the radially external end 431A and the radially internal end 432A of the first axially external circumferential anchoring element 43A.

[0220] In this eighth embodiment, the radially internal anchoring portion 541 of each first stiffening element 54A extends radially inwards at least from the radially external end 431A of the first circumferential attachment element 42A by at least 10%, preferably at least 20% of the length Ll' of the first axially external circumferential attachment element 43A. In this case, Ll' = 15 mm and the length of the radially internal anchoring portion 541 from the radially external end 431A is here substantially equal to 11 mm.

[0221] The ninth embodiment illustrated in [Fig. 1 1] differs from the first embodiment in that the carcass reinforcement 48 comprises a radially and axially internal carcass layer 50 and a radially and axially external carcass layer 51. The bead 32A comprises circumferential axially internal 42A, axially intermediate 43A and axially external 45A attachment elements.

[0222] The radially and axially inner carcass layer 50 extends radially along the first axially inner circumferential hooking element 42A and along the first axially intermediate circumferential hooking element 43A, the first axially inner circumferential hooking elements 42A and axially intermediate 43A being axially adjacent to the radially and axially inner carcass layer 50.

[0223] The radially and axially outer carcass layer 51 extends radially along the first axially intermediate circumferential anchoring element 43A and along the first axially outer circumferential anchoring element 45A, the first axially intermediate circumferential anchoring elements 43A and axially external 45A being axially adjacent to the carcass layer radially and axially external 51.

[0224] Each circumferential anchoring element 42A, 43A, 45A is arranged radially inside the first radially internal reinforcing structure 38A and extends radially inward within the first bead 32A from a radially external end 421A, 431A, 451A respectively to a radially internal end 422A, 432A, 452A respectively. The radially internal anchoring portion 541 extends, as in the first embodiment, from the first radially internal reinforcing structure 38A, radially inward at least partially along said first circumferential anchoring element 42A, which is axially adjacent to the radially internal anchoring portion 541. Comparative tests

[0225] A tire according to the fifth embodiment illustrated in [Fig. 7] was tested, as well as a control tire identical to the tire according to the fifth embodiment, but in which the radially inner anchoring portion of each stiffening element extends into each first and second zone located axially between the carcass layer and each first and second circumferential axially inner anchoring element, and located radially between the radially outer end and the radially inner end of each first and second circumferential axially inner anchoring element. 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 induce degradation of the stiffening structure.

[0226] The test tire has traveled 2 revolutions after which a separation of the first axially inner circumferential hooking element is observed, leading to a sudden loss of tire pressure.

[0227] The tire according to the invention also completed two laps, after which the stiffening elements in the first bead began to detach, without affecting the integrity of the rest of the tire's structure. Thus, the tire according to the invention successfully completed 18 additional laps without further damage, in particular without any sudden pressure loss, despite the loss of the benefits provided by the stiffening structure.

[0228] The invention is not limited to the embodiments previously described.

[0229] In accordance with the invention, embodiments may be envisaged in of which each first and second ridge and / or side comprises a single first and second circumferential attachment element.

[0230] It may be possible to combine the features of the invention described above previously with anchoring devices as described in application FR2315326 and / or with a sealing layer as described in application FR2315327 or the absence of a sealing layer as described in FR2315327 and / or main and supplementary stiffening elements as described in FR2315325 and / or inner and outer layers as described in FR2315328 filed on behalf of the applicant of this application.

Claims

Demands

1. A tire (10) comprising a crown (12), first and second sidewalls (30A, 30B) each extending radially inward from the crown (12), and first and second beadings (32A, 32B) extending radially inward from the first and second sidewalls (30A, 30B), respectively, the tire (10) having an internal surface (34) defining a toroidal cavity (36) for inflating the tire (10), the tire (10) having a substantially toroidal shape about an axis of revolution and comprising: - at least one first radially internal reinforcing structure (38A) arranged in the first sidewall (30A) and / or bead (32A), - a stiffening structure (52) comprising at least one first stiffening element (54A) extending continuously into the toroidal cavity (36) from at least the first sidewall (30A) and / or bulge (32A) up to at least the top (12),and comprising at least one radially internal anchorage portion (541) extending into the first flank (30A) and / or bead (32A) from a radially internal anchorage point (56A) of said first stiffening element (54A) to anchor into or around said first radially internal reinforcing structure (38A), - at least one first circumferential attachment element (42A; 43A) intended to allow the tire (10) to be attached to a mounting support, and extending radially inwards in the first sidewall (30A) and / or bead (32A) from a radially external end (421A; 431A) to a radially internal end (422A; 432A) of said first circumferential attachment element (42A; 43A), said radially internal anchoring portion (541) of said first stiffening element (54A) extending, from said first radially internal reinforcing structure (38A), radially inwards at least partially along said first circumferential attachment element (42A; 43A), said first circumferential attachment element (42A; 43A) being axially adjacent to said anchoring portion radially inward (541), - a carcass reinforcement (48) comprising at least one carcass layer (50) arranged at least in the first flank (30A) and / or bead (32A) and extending radially along said first circumferential attachment element (42A; 43A), said first circumferential element

2. a magnetic attachment point (42A; 43A) being axially adjacent to the carcass layer (50), characterized in that said radially inner anchoring portion (541) of said first stiffening element (54A) extends outside a zone (49A; 49A') located: - axially between said carcass layer (50) and said first circumferential attachment element (42A; 43A), and - radially between the radially outer end (421A; 431A) and the radially inner end (422A; 432A) of said first circumferential attachment element (42A; 43A). Pneumatic (10) according to the preceding claim, comprising: - at least one second radially internal reinforcing structure (38B) arranged in the second flank (30B) and / or bead (32B), - the stiffening structure (52) comprising at least one second stiffening element (54B) extending continuously in the toroidal cavity (36) from at least the second flank (30B) and / or bead (32B) to at least the apex (12), and comprising at least one radially internal anchoring portion (542) extending in the second flank (30B) and / or bead (32B) from a radially internal anchoring point (56B) of said second stiffening element (54B) to anchor in or around said second radially internal reinforcing structure (38B), - at least one second circumferential attachment element (42B; 43B) intended to allow the tire (10) to be attached to a mounting support, and extending radially inward into the second sidewall (30B) and / or bead (32B) from a radially outer end (421B; 43IB) to a radially inner end (422B; 432B) of said second circumferential attachment element (42B; 43B), said radially inner anchoring portion (542) of said second stiffening element (54B) extending, from said second radially inner reinforcing structure (38B), radially inward at least partially along said second circumferential attachment element (42B; 43B), said first circumferential attachment element (42B; 43B) being axially adjacent to said radially anchoring portion interior (542), - said carcass layer (50) being arranged at least in the second flank (30B) and / or ridge (32B) and extending radially the along said second circumferential attachment element (42B; 43B), said second circumferential attachment element (42B; 43B) being axially adjacent to the carcass layer (50), pneumatic in which said radially inner anchoring portion (542) of said second stiffening element (54B) extends outside of a zone (49B; 49B') located: - axially between said carcass layer (50) and said second circumferential attachment element (42B; 43B), and - radially between the radially outer end (421B; 43IB) and the radially inner end (422B; 432B) of said second circumferential attachment element (42B; 43B).

3. Pneumatic (10) according to any one of the preceding claims, wherein said radially inner anchoring portion (541) of said first stiffening element (54A) extends radially inward to a point arranged radially inside the radially outer end (421A; 431A) of said first circumferential hooking element (42A; 43A).

4. Pneumatic according to any one of claims 1 to 3, wherein said radially inner anchoring portion (541) of said first stiffening element (54) extends radially inward to a point arranged radially outside the radially inner end (422A; 432A) of said first circumferential hooking element (42A; 43A).

5. Pneumatic according to any one of claims 1 to 3, wherein said radially inner anchoring portion (541) of said first stiffening element (54) extends radially inwards to a point arranged radially inside the radially inner end (422A; 432A) of said first circumferential hooking element (42A; 43A).

6. Pneumatic (10) according to any one of the preceding claims, wherein said radially inner anchoring portion (541) of said first stiffening element (54A) extends radially inwards at least from the radially outer end (421A; 431A) of said first circumferential hooking element (42A; 43A) over at least 10%, preferably at least 20% of a length of said first circumferential hooking element (42A; 43A).

7. Pneumatic (10) according to any one of the preceding claims preceding, wherein said radially internal anchorage portion (541) of said first stiffening element (54A) comprises at least first and second branches (5411, 5412), said first branch (5411) extending radially inward and axially outward from the radially internal anchorage point (56A) of said first stiffening element (54A), said second branch (5412) extending radially inward and axially inward from said first branch (5411) or from a third branch (5413) of said first stiffening element (54A) connecting said first branch (5411) and said second branch (5412).

8. Pneumatic (10) according to the preceding claim, wherein the second arm (5412) extends radially at least in part along said first circumferential hooking element (42A; 43A).

9. Pneumatic (10) according to any one of claims 1 to 8, wherein said radially inner anchoring portion (541) of said first stiffening element (54A) extends radially inwards at least in part along said first circumferential hooking element (42A; 43A) without being anchored in the first circumferential hooking element (42A; 43A).

10. Pneumatic (10) according to any one of claims 1 to 8, wherein said radially inner anchoring portion (541) of said first stiffening element (54A) extends radially inwards at least in part along said first circumferential hooking element (42A; 43A) being anchored in or around said first circumferential hooking element (42A; 43A).

11. A tire (10) according to any one of the preceding claims, comprising a first axially internal circumferential hooking element (42A) and a first axially external circumferential hooking element (43A) intended to allow the tire (10) to be hooked onto a mounting support, and arranged radially inside said first radially internal reinforcement structure (38A), each first axially internal (42A) and external (43A) circumferential hooking element being axially adjacent to the carcass layer (50) and extending radially inwards into the first sidewall (30A) and / or bead (32A) from a radially external end (421A, 431A) to a radially internal end (422A, 432A) respectively of said first axially internal circumferential hooking element (42A) and exterior (43A), said carcass layer (50) extends radially along each first internal axially internal (42A) and external (43A) circumferential anchoring element and axially between said first internal axially internal circumferential anchoring element (42A) and said first external axially external circumferential anchoring element (43A).

12. Pneumatic (10) according to claim 11, wherein said radially inner anchoring portion (541) of said first stiffening element (54A) extends at least in part axially within said first circumferential axially inner hooking element (42A).

13. Pneumatic (10) according to claim 11, wherein said radially inner anchoring portion (541) of said first stiffening element (54A) axially traverses said carcass layer (50) and extends at least partially axially outside said first circumferential axially outer hooking element (43A).

14. Pneumatic (10) according to any one of the preceding claims, wherein said first radially internal reinforcement structure (3 8A) comprises a first circumferential radially internal reinforcement element (40A) distinct from the first circumferential hooking element (42A; 43A).