Tire comprising a layer of thermoplastic polymer composition arranged between a stiffening structure and a reinforcement structure

Abstract

This tire (10) comprises sidewalls (30A, 30B), beads (32A, 32B), a stiffening structure (52) anchored in the first sidewall (30A) and / or bead (32A) around a radially inner reinforcement structure (38A). The tire (10) comprises a radially inner layer of thermoplastic polymer composition (60A) arranged between said stiffening structure (52) and said radially inner circumferential reinforcement structure (38A).

Description

[0001] A tire comprising a layer of thermoplastic polymer composition interposed between a stiffening structure and a reinforcing structure.

[0002] technical field

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

[0004] A tire is defined as a band 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 tire according to the invention has a substantially toroidal structure of revolution around a principal axis of the tire, this principal axis coinciding with the axis of rotation of the tire.

[0005] Previous techniques

[0006] 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 ribs designed to contact a mounting support, such as a rim. Each first and second bead includes a circumferential reinforcing element to secure the tire to the mounting support.

[0007] The tire includes an internal surface defining a toroidal cavity for inflating the tire once it is mounted on the mounting support.

[0008] The tire described in WO2020 / 128225 comprises a stiffening structure including first stiffening elements extending continuously within the toroidal cavity from the first bead to the apex and second stiffening elements extending continuously within the toroidal cavity from the second bead to the apex. Each first and second stiffening element is fixed to each bead from which it extends by a bead interface between the stiffening element and a portion of the inner surface of the bead. Similarly, each first and second stiffening element is fixed to the apex of the tire by an apex interface between the stiffening element and a portion of the inner surface of the apex. Each bead-apex interface includes an elastomeric compound cushion positioned between the stiffening element and the corresponding portion of the inner surface.

[0009] It was observed 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 internal surface, and therefore to premature failure of the stiffening structure.

[0010] The durability of the tire described in WO2020 / 128225 was improved in W02022 / 200717 through the use of anchoring for each first and second stiffening element within the tire's internal structure. Nevertheless, the durability of the tire described in W02022 / 200717, particularly the durability of the anchoring of the first and second stiffening elements in each first and / or bead, while significantly improved compared to that of the tire described in WO2020 / 128225, proved imperfect due to failures of some of the first and second stiffening elements in certain use cases.

[0011] The invention aims to improve the endurance of the stiffening structure described in WO2020 / 128225 and W02022 / 200717.

[0012] Description of the invention

[0013] 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 a stiffening structure extending continuously in the toroidal cavity from at least the first sidewall and / or bead to at least the crown, said stiffening structure being anchored at least in the first sidewall and / or bead and / or the crown,said stiffening structure being anchored in or around a first radially internal reinforcement structure of the tire arranged in the first sidewall and / or bead and / or in or around one or more radially external reinforcement structure(s) arranged in the crown.

[0014] The tire comprises a first layer of radially inner thermoplastic polymer composition interposed between said stiffening structure and said first radially inner reinforcement structure. Alternatively or in combination, the tire comprises a layer of radially outer thermoplastic polymer composition interposed between said stiffening structure and said or one of said radially outer reinforcement structure(s).

[0015] 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, and / or as soon as it is applied to the crown. Advantageous embodiments allow the invention to be applied to both sides of the tire, although this is not necessary to achieve the invention. Thus, in the present application, the use of the qualifier "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 qualifier "second" is intended, unless otherwise obviously interpreted, to associate the element designated as "second" with the second sidewall and / or bead. 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-velocity drifts. The inside and outside edges refer to the fact that the tire is designed so that one side is oriented on the inside and the other on the outside. This orientation, imposed by the tire manufacturer, ensures that the tire performs as intended. Indeed, mounting a tire with an orientation different from that specified by the manufacturer can lead to suboptimal vehicle handling. The outside edge refers to the side of the tire fully visible from outside the vehicle when the tire is mounted. The inside edge refers to the side of the tire facing the wheel well of the vehicle on which it is mounted. Generally, the tire has markings indicating the inside and outside edges.

[0016] In a preferred embodiment in which the stiffening structure performs its function on both sides of the median plane of the tire, thus enabling homogeneous tire behavior, said stiffening structure extends continuously in the toroidal cavity from at least the second sidewall and / or bead to at least the apex, said stiffening structure being anchored at least in the second sidewall and / or bead, said stiffening structure being anchored in or around a second radially internal reinforcement structure of the tire arranged in the second sidewall and / or bead, tire comprising a second radially internal layer of thermoplastic polymer composition interposed between said stiffening structure and said second radially internal reinforcement structure.

[0017] It has been observed that the stiffening structure degrades, sometimes to the point of failure, due to friction and contact between the stiffening structure and the relevant reinforcement structure. This failure occurs particularly at the point where the stiffening structure is anchored. In particular, in cases where the stiffening structure exhibits relatively high temperature sensitivity, its contraction can lead to closer contact between the stiffening structure and the relevant reinforcement structure, resulting in significant friction and contact during tire use.

[0018] Each layer of thermoplastic polymer composition limits friction and contact between the stiffening structure and the relevant reinforcement structure, preventing degradation that could lead to at least partial failure of the stiffening structure in certain usage scenarios. The protective function is achieved, firstly, by the mechanical decoupling of the thermoplastic polymer composition layer between the stiffening and reinforcement structures. Secondly, the protective function is achieved by creating a distance between the stiffening and reinforcement structures. This distancing means that the stiffening structure is not in direct contact with the reinforcement structure.This distancing is guaranteed by the size of the thermoplastic polymer composition layer which creates the space necessary to protect the stiffening structure.

[0019] Furthermore, the layer of thermoplastic polymer composition considered makes it possible to increase the surface area over which the forces transmitted from said stiffening structure to said corresponding radially internal and / or external reinforcement structure are distributed, and therefore to reduce these forces.

[0020] A polymeric composition comprises one or more polymers. A thermoplastic composition is capable of softening under the effect of relative heating and hardening under the effect of relative cooling, and this process is reversible. Thus, a thermoplastic polymeric composition comprises one or more thermoplastic polymers. Well-known examples of such thermoplastic polymers are aliphatic polyamides, polyesters, thermoplastic elastomers, and mixtures thereof. Of course, the polymer layer may include compounds other than the thermoplastic polymer(s).

[0021] A thermoplastic polymer composition is to be contrasted with a crosslinkable or vulcanizable polymer composition, for example based on an elastomer and a crosslinking or vulcanization system which, under the effect of relative heating, hardens irreversibly.

[0022] One of the advantages of the thermoplastic polymer composition related to the invention is its ease of manufacture. Indeed, it can easily be interposed between the stiffening structure and the relevant reinforcing structure by heating the thermoplastic polymer material to give it the desired shape to form the layer.

[0023] Thus, an anchorage according to the invention is significantly more robust than the bead interfaces described in WO2020 / 128225 and the anchorage described in W02022 / 200717.

[0024] By interposition, we mean that the layer of thermoplastic polymer composition is positioned geometrically between the stiffening structure and the relevant reinforcing structure.

[0025] Of course, we can have one or more radially inner thermoplastic polymeric composition(s) layer(s) and / or one or more radially outer thermoplastic polymeric composition(s).

[0026] In addition, in addition to the layer(s) of thermoplastic polymer composition(s), a layer of a composition other than a thermoplastic polymer composition may be interposed between the stiffening structure and the relevant radially internal and / or external reinforcing structure, for example a layer of a crosslinkable polymer composition.

[0027] The toroidal inflation cavity is designed to be pressurized by an inflation gas once the tire is mounted on a mounting support, most often a rim. Among other advantages, the stiffening structure allows for a simultaneous increase in the radial stiffness, axial stiffness, and drift stiffness of the tire compared to a conventional tire without a stiffening structure, but also compared to tires with other stiffening structures, such as the one described in WO2017 / 005713.

[0028] By increasing radial stiffness, the stiffening structure limits radial deformation of the tread 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 especially 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 remains unchanged, which allows the tire to maintain the same grip performance as the tire described in WO2017 / 005713.

[0029] By increasing axial and drift stiffness, the stiffening structure will contribute to improved behavior under lateral stress, for example during a drift roll. Furthermore, under lateral stress, the contact area with the ground ensures a more homogeneous distribution of contact pressures, thus increasing lateral grip.

[0030] Furthermore, the stiffening structure contributes at least partially to the load-bearing capacity of the tire, such that this applied load is jointly supported by the tire, thanks to its inherent pneumatic and structural rigidity, and by the stiffening structure. Thus, when the tire is subjected to a nominal radial load, a portion of the stiffening structure located opposite the contact patch is placed under tension. Conversely, in some embodiments, a portion of the stiffening structure located at the contact patch is subjected to buckling under compression. The presence of the stiffening structure therefore reduces the tire's contribution to load-bearing capacity and thus allows for a reduction in its structural rigidity, for example, by reducing the volume of the sidewalls.Indeed, the beading of a conventional tire dissipates a significant amount of energy due to its volume and the hysteretic nature of its constituent elastomeric compound. Reducing its volume thus significantly reduces rolling resistance.

[0031] 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 classically used by those skilled in the art: an axial direction, a circumferential direction, and a radial direction.

[0032] Axial direction means the direction substantially parallel to the axis of revolution of the tire, that is to say the axis of rotation of the tire.

[0033] 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).

[0034] 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.

[0035] 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 ridges and passes through the axial midpoint of the apex reinforcement.

[0036] The circumferential equatorial plane of the tire, denoted E, is defined, in a meridional cross-sectional plane, as 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 cross-sectional plane (a 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.

[0037] By meridian plane, we mean a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0038] Radially inside and radially outside refer to the area closest to and furthest from the tire's axis of rotation, respectively. Axially inside and axially outside refer to the area closer to and furthest from the tire's median plane, respectively.

[0039] The bead is the radial portion of the tire designed to allow the tire to be attached to a mounting surface, such as a wheel with a rim. Each bead is specifically designed to make contact with a hook on the rim, enabling it to be attached. The bead is thus delimited radially on the inside by the innermost radial end of the tire and radially on the outside 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 (ETRTO) standard, 2024.

[0040] The sidewall is defined as the radial portion of the tire connecting the bead to the crown. The sidewall is radially delimited externally by a tread edge. 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 2024 standard manual. The edges are arranged on either side of the tire's median plane and are formed by lines substantially parallel to the tire's circumferential direction. If there is a clear boundary between the tread and the sidewall, the edges are determined simply. If 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 2024 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, 2024.

[0041] Any range of values ​​designated by the expression "between a and b" represents the range of values ​​from more than a to less than b (i.e., bounds a and b excluded) while any range of values ​​designated by the expression "from a to b" means the range of values ​​from a to b (i.e., including the strict bounds a and b).

[0042] The tires of the invention are preferably intended for passenger vehicles as defined in the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2024. 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, 2024. The values ​​of SW and H are indicated on the tire sidewall marking, for example as defined according to the ETRTO manual, 2024.

[0043] Preferably, the passenger vehicle tires to which the invention will be advantageously applied are such that the H / S ratio, expressed as a percentage, is at most 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.

[0044] In optional and advantageous embodiments, the stiffening structure extending in the toroidal cavity from at least the first flank and / or bead to at least the apex being anchored in the apex, and extending in the toroidal cavity from at least the second flank and / or bead to at least the apex being anchored in the apex, said stiffening structure being anchored in or around one or more radially external reinforcing structure(s) arranged in the apex, the tire includes a layer of radially external thermoplastic polymer composition interposed between said stiffening structure and said or one of said radially external reinforcing structure(s).

[0045] Advantageously:

[0046] - said first layer of radially inner thermoplastic polymer composition is in contact with said stiffening structure and / or said first radially inner reinforcement structure, and / or said layer of radially outer thermoplastic polymer composition is in contact with said stiffening structure and / or said or one of said radially outer reinforcement structure(s).

[0047] Optionally, said second layer of radially inner thermoplastic polymer composition is in contact with said stiffening structure and / or said second radially inner reinforcing structure.

[0048] Alternatively, the relevant thermoplastic polymer composition layer is not in contact with said stiffening structure, for example because a composition layer other than a thermoplastic polymer composition layer is interposed between the stiffening structure and the relevant radially internal and / or external reinforcing structure.

[0049] Advantageously, said stiffening structure includes at least one first stiffening element comprising:

[0050] - a radially internal anchoring portion extending into the first flank and / or bead, said first layer of radially internal thermoplastic polymer composition being interposed between said first radially internal reinforcement structure and the radially internal anchoring portion of said first stiffening element, and / or - a radially external anchoring portion extending into the top, said layer of radially external thermoplastic polymer composition being interposed between said or one of said radially external reinforcement structure(s) and the radially external anchoring portion of said first stiffening element.

[0051] Optionally, said stiffening structure includes at least a second stiffening element comprising a radially internal anchoring portion extending into the second flank and / or bead, said second layer of radially internal thermoplastic polymer composition is interposed between said second radially internal reinforcing structure and the radially internal anchoring portion of said second stiffening element.

[0052] Advantageously: said first layer of radially inner thermoplastic polymer composition is in contact with the radially inner anchoring portion of said first stiffening element and of said first radially inner reinforcing structure and / or said layer of radially outer thermoplastic polymer composition is in contact with the radially outer anchoring portion of said first stiffening element and / or of said or one of said radially outer reinforcing structure(s).

[0053] Optionally, said second layer of radially inner thermoplastic polymer composition is in contact with the radially inner anchoring portion of said second stiffening element and said second radially inner reinforcing structure.

[0054] Advantageously, said first stiffening element penetrates the top at a first radially external anchor point of said first stiffening element.

[0055] Optionally, said second stiffening element penetrates the apex at a second radially external anchor point of said second stiffening element. Advantageously, said first stiffening element comprises a portion extending continuously within the toroidal cavity from the first radially internal anchor point to the first radially external anchor point.

[0056] Advantageously, the radially inner anchoring portion of said first stiffening element extends the portion extending continuously into the toroidal cavity.

[0057] Advantageously, said first stiffening element includes a radially external anchoring portion extending from the first radially external anchoring point in the apex and extending the portion extending continuously into the toric cavity.

[0058] Optionally, said second stiffening element includes a portion extending continuously in the toroidal cavity from the second radially inner anchor point to the second radially outer anchor point.

[0059] Optionally, the radially inner anchoring portion of said second stiffening element extends the portion extending continuously into the toroidal cavity.

[0060] 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.

[0061] Advantageously, said radially external anchorage 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.

[0062] 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.

[0063] Optionally, said radially external anchorage portion of said second stiffening element is anchored in the apex by being anchored in or around one or more radially external reinforcing structures of the stiffening structure arranged in the apex.

[0064] 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.

[0065] Each internal or external radial reinforcement structure is respectively arranged within the corresponding side and / or flange or in the top; that is, arranged axially and / or radially within the internal surface and embedded in the mass of materials constituting the corresponding side and / or flange or the top. The stiffening structure passes through the internal surface to anchor itself in or around the corresponding internal radial reinforcement structure and / or through the internal surface to anchor itself in or around the external radial reinforcement structure(s).

[0066] As previously stated, the stiffening structure can be anchored in or around at least one internal and / or external radially reinforcing structure.

[0067] 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.

[0068] 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.

[0069] In a second variant, the stiffening structure can be anchored around the very structure of said reinforcement structure, 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.

[0070] 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.

[0071] According to an initial conception:

[0072] - said first radially internal reinforcing structure comprising a first circumferential radially internal reinforcing element, said first layer of radially internal thermoplastic polymer composition forming a sheath of said first circumferential radially internal reinforcing element and / or

[0073] - said or one of said radially external reinforcing structure(s) comprising a radially external reinforcing circumferential element, said radially external thermoplastic polymer composition layer forms a sheath of said radially external reinforcing circumferential element.

[0074] Optionally, according to the first design, said second radially internal reinforcement structure comprising a second circumferential radially internal reinforcement element, said second layer of radially internal thermoplastic polymer composition forms a sheath of said second circumferential radially internal reinforcement element.

[0075] The term "forms a sheath" of the circumferential element in question means that the relevant layer of thermoplastic polymer composition covers and surrounds said circumferential element in question. In other words, the relevant layer of thermoplastic polymer composition encases said circumferential element in question.

[0076] According to a second interpretation:

[0077] - said first layer of radially inner thermoplastic polymer composition forms a band of radially inner thermoplastic polymer composition interposed between said stiffening structure and said first radially inner reinforcement structure, and / or said layer of radially outer thermoplastic polymer composition forms a band of radially outer thermoplastic polymer composition interposed between said stiffening structure and said or one of said radially outer reinforcement structure(s).

[0078] Optionally, according to the second design, said second layer of radially inner thermoplastic polymer composition forms a band of radially inner thermoplastic polymer composition interposed between said stiffening structure and said second radially inner reinforcing structure.

[0079] Advantageously, said first layer of radially inner thermoplastic polymer composition and / or said layer of radially outer thermoplastic polymer composition has a melting point greater than or equal to 175 °C, preferably 200 °C and more preferably 225 °C.

[0080] Optionally, said second layer of radially inner thermoplastic polymer composition has a melting point greater than or equal to 175°C, preferably 200°C and more preferably 225°C.

[0081] Such thermoplastic polymer layers soften at relatively high temperatures, well above the usual tire curing temperatures. Therefore, during tire curing, the thermoplastic polymer layer remains relatively rigid, reducing or even eliminating the risk of the stiffening structure penetrating the thermoplastic polymer layer and thus the risk of contact between the stiffening structure and the relevant reinforcement structure.

[0082] The melting point of the relevant thermoplastic polymer composition layer is measured according to ISO 3146:2022. Advantageously, said first radially inner thermoplastic polymer composition layer and / or said radially outer thermoplastic polymer composition layer comprises a thermoplastic aliphatic polyamide and / or a polyester and / or a thermoplastic elastomer.

[0083] Optionally, said second layer of radially inner thermoplastic polymer composition comprises a thermoplastic aliphatic polyamide and / or a polyester and / or a thermoplastic elastomer.

[0084] Advantageously, in embodiments comprising a first radially internal reinforcing structure arranged in the first flange and / or bead, this structure includes at least one first circumferential radially internal reinforcing element. This first circumferential radially internal reinforcing element allows the stiffening structure to be anchored in the first flange and / or bead.

[0085] Optionally, in embodiments comprising a second radially internal reinforcing structure arranged in the second flange and / or bead, this structure preferably includes at least one second circumferential radially internal reinforcing element. This second circumferential radially internal reinforcing element allows the stiffening structure to be anchored in the second flange and / or bead.

[0086] Advantageously, the first internal radially internal circumferential reinforcing element and / or the second internal radially internal circumferential reinforcing element is wound circumferentially for at least one complete turn around the axis of revolution, preferably for several complete turns around the axis of revolution. Two consecutive turns may or may not be in contact with each other.

[0087] In one embodiment, said first circumferential radially internal reinforcing element comprises a metallic wire reinforcing element.

[0088] Advantageously, said first circumferential radially internal reinforcing element comprises an assembly of a plurality of metallic monofilaments, each with a diameter between 0.15 and 0.45 mm, preferably between 0.20 and 0.40 mm. Alternatively, said first circumferential radially internal reinforcing element comprises a textile yarn reinforcing element.

[0089] Optionally, said second circumferential internal radial reinforcement element includes a metallic wire reinforcement element.

[0090] Advantageously, the first radially inner thermoplastic polymer composition layer is covered with a layer based on an adhesive composition and / or, the radially outer thermoplastic polymer composition layer is covered with a layer based on an adhesive composition.

[0091] Optionally, the second inner radially thermoplastic polymeric composition layer is covered with a layer based on an adhesive composition.

[0092] The adhesive composition is preferably based on a resin chosen from among aldehyde / phenol resins, polyepoxide resins, polyisocyanate resins, aromatic polyepoxy-phenolic resins and polyfunctional resins as well as mixtures of these resins.

[0093] Alternatively, self-adhesive thermoplastic polymer compositions can be used, thus avoiding the use of the adhesive compositions described above. Examples of thermoplastic polymer compositions are described in EP2643515, EP2618976, EP2408612, EP2435627, EP2494105,

[0094] EP2459358.

[0095] Advantageously, said second circumferential radially inward reinforcing element comprises an assembly of a plurality of metallic monofilaments, each with a diameter between 0.15 and 0.45 mm, preferably between 0.20 and 0.40 mm. Alternatively, said second circumferential radially inward reinforcing element comprises a textile yarn reinforcing element. Advantageously, said first and / or second circumferential radially inward reinforcing element extends along a principal direction forming an angle of less than or equal to 10° with the circumferential direction of the tire, preferably less than or equal to 5°, and more preferably substantially zero.

[0096] In embodiments comprising at least one radially external reinforcing structure arranged in the apex, this structure preferably includes a circumferential radially external reinforcing element. This circumferential radially external reinforcing element allows the stiffening structure to be anchored in the apex.

[0097] Advantageously, the circumferential element or each radially external reinforcement element is circumferentially wound at least one full turn around the axis of revolution, preferably several full turns around the axis of revolution.

[0098] In one embodiment, the radially external circumferential reinforcement element of the radially external reinforcement structure(s) comprises a metallic wire reinforcement element. Advantageously, the radially external circumferential reinforcement element comprises an assembly of a plurality of metallic monofilaments, each with a diameter between 0.15 and 0.45 mm, preferably between 0.20 and 0.40 mm. Alternatively, the radially external circumferential reinforcement element of the radially external reinforcement structure(s) comprises a textile wire reinforcement element.

[0099] Advantageously, the circumferential radially external reinforcement element(s) extend along a principal direction forming with the circumferential direction of the tire an angle less than or equal to 10°, preferably less than or equal to 5° and more preferably substantially zero.

[0100] In some 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.

[0101] This reduces the mass of the reinforcement structure used to anchor the stiffening structure at the top and limits the over-fretching of the top, thus maintaining a regular contact area.

[0102] 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.

[0103] This improves the axial distribution of the forces exerted by the stiffening structure on the apex.

[0104] In other embodiments, the tire comprises a single radially external reinforcement structure extending continuously on each side of the tire's median plane.

[0105] Each internal radially internal circumferential reinforcement element and each external radially external circumferential reinforcement element may be wound in various ways as described in particular in W02022 / 200717.

[0106] Of course, the tire may include several of the aforementioned first and / or second radially internal and / or external reinforcement structures.

[0107] Typically, in a tire with a crown reinforcement and a carcass reinforcement, the crown comprises a tread designed 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 into each sidewall and axially into the crown, radially within the crown reinforcement. Conventionally, the crown reinforcement includes at least one crown layer with reinforcing elements. These reinforcing elements are preferably textile or metallic wires.

[0108] In embodiments enabling the achievement of radial tire performance 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 an angle, in absolute value, of 80° to 90° with the circumferential direction of the tire. Alternatively, a variable angle of 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.

[0109] In an advantageous embodiment, the stiffening structure is not airtight to the tire's 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 within the toroidal cavity at all times, and particularly during tire inflation.

[0110] 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.

[0111] Advantageously, 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.

[0112] 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 axial buckling of the tread, i.e., axial compression of the tread, particularly under conditions of high lateral stress. Consequently, a regular contact area is maintained, and the risk of damage to the tire's crown reinforcement is reduced, notably by preventing compression of the various components of the crown reinforcement, such as the textile and metallic wire reinforcement elements.

[0113] Preferably, the stiffening structure comprises a plurality of first stiffening elements distributed circumferentially in the toric cavity.

[0114] Optionally, the stiffening structure includes a plurality of second stiffening elements distributed circumferentially in the toroidal cavity.

[0115] 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 apex. Preferably, each second stiffening element also forms a continuous second stiffening element that meanders at least from the second flank and / or bead through the apex.

[0116] This simplifies tire manufacturing and improves the robustness of the stiffening structure by eliminating the need for anchoring the ends of the stiffening element in each sidewall and / or bead and / or crown. In this configuration, a continuous stiffening element extending around the entire circumference of the tire is possible. Because this stiffening element is continuous, the transmission of forces between each sidewall and / or bead is improved, as the forces are distributed across the tire. Thus, the stiffening structure performs its function around the entire circumference of the tire.

[0117] 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.

[0118] According to a second variant of the first stiffening element configuration, each first stiffening element forms a continuous stiffening element that meanders between the first flank and / or bead and the apex. Again 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.

[0119] In a second configuration of the stiffening elements, each first stiffening element could extend from the first side and / or bead to the top and have one end in the first side and / or bead. Similarly, each second stiffening element could extend from the second side and / or bead to the top and have one end in the second side and / or bead.

[0120] In a first variation of this second configuration, each first stiffening element could extend from the first side and / or bead to the apex and have one end at the apex. Similarly, each second stiffening element could extend from the second side and / or bead to the apex and have one end at the apex.

[0121] 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.

[0122] Each stiffening element, according to one of the previously defined designs or configurations, can be characterized geometrically, in particular by its average cross-sectional area Sm. This characteristic is not necessarily identical for all 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.As examples, a stiffening element having a circular average section Sm, having a diameter equal to d, has a form ratio R= l, a stiffening element having a rectangular average section Sm, having a length L and a width 1, has a form ratio R=L / 1, and a stiffening element having an elliptical average section Sm, having a major axis D and a minor axis d, has a form ratio R=D / d.

[0123] A 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 exhibits wire-like mechanical behavior, meaning it can only be subjected to tensile or compressive forces along its neutral axis. This is why a one-dimensional stiffening element is commonly 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 section Sm being substantially circular, the shape ratio R is equal to 1, therefore less than 3.

[0124] 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 three 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 one variant, a stiffening element with an aspect ratio R of at least 3 and at most 50 is called a two-dimensional strip-type element. According to a second variant, a stiffening element with an aspect ratio R of at least 50 is called a two-dimensional film-type element.

[0125] The materials that can be used for each stiffening element are as described in W02022 / 200717.

[0126] 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.

[0127] These wire stiffening elements are commonly called stays. The advantage of using wire stiffening elements is that they provide a low-mass, low-hysteresis stiffening structure. Using identical wire stiffening elements ensures a homogeneous distribution of stress between them.

[0128] By textile, we mean that each wire stiffening element is non-metallic, for example, made of a material chosen from among 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.

[0129] Advantageously, in an alternative method 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 from 85° to 90° in absolute value. In another alternative method 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 from 45° to 85° in absolute value, as explained in particular in WO2020 / 128225.

[0130] In a preferred variant, each first and second bead comprises respectively a first and second circumferential radially internal reinforcement element intended to enable the tire to be attached to a tire mounting support, said first circumferential radially internal reinforcement element or each first and second circumferential radially internal reinforcement element being arranged radially outside each first and second circumferential reinforcement element intended to enable the tire to be attached to a tire mounting support.

[0131] This reduces the transmission of noise generated by the stiffening structure from the stiffening structure to the vehicle via the tire mounting bracket. The noise generated by the stiffening structure is dampened by the tire structure separating the internal radial reinforcement element from the internal radial reinforcement element designed to secure the tire to a mounting bracket located on the same side of the tire's median plane.

[0132] This damping is the result of the fact that the circumferential radially internal reinforcement element considered is mechanically decoupled from said circumferential radially internal reinforcement element intended to allow the tire to be attached to a tire mounting support located on the same side of the tire's median plane.

[0133] Optionally, the first circumferential hooking element is arranged radially inside said first radially inner reinforcement structure by being wrapped circumferentially around the axis of revolution.

[0134] Optionally, the second circumferential hooking element is arranged radially inside said second radially inner reinforcement structure by being wrapped circumferentially around the axis of revolution.

[0135] 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.

[0136] 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.

[0137] Alternatively, said first internal radially reinforcing circumferential element or each first and second internal radially reinforcing circumferential element is intended to permit the attachment of the tire to a tire mounting support.

[0138] Brief description of the drawings

[0139] The present invention will be better understood upon study of the detailed description of embodiments, taken by way of non-limiting examples and illustrated by the accompanying drawings, in which:

[0140] - Figure 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;

[0141] - Figures 2 and 3 are schematic representations of the arrangement of the stiffening structure of Figure 1 in each first and second flank and / or bead;

[0142] - Figures 4 and 5 are schematic representations of the arrangement of the stiffening structure of Figure 1 at the apex; and

[0143] - Figure 6 is a view similar to that of Figure 2 of a tire according to a second embodiment of the invention.

[0144] Detailed description

[0145] In the figures relating to the tire, we have represented a coordinate system X, Y, Z corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0146] 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., having not yet been driven on. The tire 10 described with reference to Figures 1 to 5 comprises a crown 12 including a tread 14 intended to come into contact with the ground during driving and a crown reinforcement 16 extending into the crown 12 along the circumferential direction X. The tire 10 also includes an inner layer 18.

[0147] The tire 10 includes a top reinforcement identical to that described W02022 / 200717 comprising a working reinforcement 20 including working layers 24, 26 and a shrink-fit reinforcement 22 including a shrink-fit layer 28.

[0148] The tire 10 comprises first and second sidewalls 30A, 30B extending radially inwards from the apex 12. The second sidewall 30B is opposite the first sidewall 30A with respect to the median plane M. The tire 10 has first and second bead 32A, 32B extending radially inwards from each first and second sidewall 30A, 30B, respectively. The second bead 32B is opposite the first bead 32A with respect to the median plane M. Each first and second sidewall 30A, 30B connects each first and second bead 32A, 32B respectively to the apex 12. The tire 10 is provided with an internal surface 34, intended to be in contact with the tire inflation gas, and which delimits a toroidal cavity 36 for inflating the tire 10. The internal surface 34 is here supported by the inner layer 18.

[0149] The tire 10 includes first and second radially internal reinforcement structures 38A, 38B respectively arranged in each first and second bead 32A, 32B.

[0150] Each first and second radially internal reinforcement structure 38A, 38B respectively comprises at least first and second circumferential radially internal reinforcement elements 40A, 40B, respectively arranged in each first and second bead 32A, 32B.

[0151] As more clearly illustrated in Figures 2 and 3, each first and second radially internal circumferential reinforcing element 40A, 40B respectively comprises first and second metallic wire reinforcing elements, each consisting of an assembly of a plurality of metallic monofilaments. Each assembly comprises an inner layer of two elementary metallic monofilaments wound helically, for example, at a 5 mm pitch, and an outer layer of seven elementary metallic monofilaments wound helically around the inner layer, for example, at a 10 mm pitch.

[0152] As an indication, the metallic monofilaments can each have a diameter between 0.15 and 0.45 mm, and more precisely between 0.20 and 0.40 mm and here have a diameter of 0.35 mm.

[0153] Each first and second bead 32A, 32B respectively comprises a first and second circumferential internal axially gripping element 42A, 42B and a first and second circumferential external axially gripping element 43A, 43B, each here comprising a rod, and intended to allow the tire 10 to be attached to a tire mounting support 10, for example, a rim. Each first and second circumferential internal axially gripping element 42A, 42B is arranged respectively inside each first and second circumferential external axially gripping element 43A, 43B. Each first circumferential internal axially gripping element 42A is distinct from each first circumferential external axially gripping element 43A.Each second internal axially attached circumferential element 42B is distinct from each second external axially attached circumferential element 43B.

[0154] Each first and second circumferential internal axially gripping element 42A, 42B and externally axially gripping element 43A, 43B is circumferentially wound 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 of the tire 10, and here over eight full turns for the first and second circumferential internal axially gripping elements 42A, 42B and over seven full turns for the first and second circumferential external axially gripping elements 43A, 43B, so as to extend respectively into the first or second bead 32A,32B radially inwards from a corresponding radially outward end to a corresponding radially inward end, defining a length of the axially concerned circumferential attachment elements.

[0155] Each first and second circumferential internal axially hooking element 42A, 42B and externally axially hooking element 43A, 43B is arranged radially inside respectively each first and second radially internal reinforcing structure 38A, 38B, in particular each first and second circumferential internal axially hooking element 42A, 42B and externally axially hooking element 43A, 43B is arranged radially inside respectively each first and second circumferential radially internal reinforcing element 40A, 40B.

[0156] Each first circumferential internal radial reinforcement element 40A is distinct from each first circumferential internal axial attachment element 42A and external axial attachment element 43A. Each second circumferential internal radial reinforcement element 40B is distinct from each second circumferential internal axial attachment element 42B and external axial attachment element 43B.

[0157] The tire 10 comprises first and second radially external reinforcement structures 44A, 44B arranged in the apex 12 and each respectively provided with a first and second circumferential radially external reinforcement element 46A, 46B arranged axially on either side of the median plane M of the tire 10 and here substantially symmetrically with respect to the median plane M of the tire 10. Each first and second circumferential radially external reinforcement element 46A, 46B is as described in W02022 / 2007 17.

[0158] Each first and second radially internal (40A, 40B) and external (46A, 46B) circumferential reinforcing element extends along a principal direction forming an angle of less than or equal to 10° with the circumferential direction X, preferably less than or equal to 5°, and here substantially zero. Each first and second radially internal (40A, 40B) and external (46A, 46B) circumferentially wound around the axis of revolution Y at least one full turn and preferably several full turns.

[0159] 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 of the first and second sidewalls 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 W02022 / 200717.

[0160] The carcass layer 50 is therefore arranged in each first and second flank 30A, 30B and ridge 32A, 32B and anchored in each first and second ridge 32A, 32B.

[0161] In this case, the carcass layer 50 extends axially between each first and second circumferential internal axial attachment element 42A, 42B and each first and second circumferential external axial attachment element 43A, 43B. Each first and second circumferential internal axial attachment element 42A, 42B and the axially external attachment element 43A, 43B are axially adj acent to the carcass layer 50 respectively in each first and second bead 32A, 32B.

[0162] The carcass layer 50 extends radially along each first and second circumferential internal axially internal 42A, 42B and external 43A, 43B attachment element.

[0163] The tire 10 includes a stiffening structure 52 extending in the toroidal cavity 36 from the first bead 32A to the apex 12 and which is 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.

[0164] The stiffening structure 52 comprises a plurality of stiffening elements 54 including 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.

[0165] Each stiffening element 54 is a textile yarn stiffening element comprising an assembly of three multifilament strands of aliphatic polyamide, for example nylon, these three multifilament strands being individually helicalized at 190 turns per meter in one direction and then helicalized together at 190 turns per meter in the opposite direction. Each of these multifilament strands has a count of 188 tex.

[0166] 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.

[0167] In order to ensure optimal anchoring of the first and second stiffening elements 54A, 54B, each first and second radially internal reinforcement structure 38A, 38B, in particular each first and second circumferential radially internal reinforcement element 40A, 40B, has relatively high tensile and flexural stiffnesses.

[0168] 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 the over-fretching of the top 12 and not risk damaging the flatness of the tread 14.

[0169] 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.

[0170] Each first and second stiffening element 54A, 54B is also anchored, at 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.

[0171] Each first stiffening element 54A passes through the internal surface 34 at a first radially internal anchor point 56A in the first bead 32A to anchor around the first radially internal reinforcement structure 38A and at a first radially external anchor point 58A in the apex 12 to anchor around the first radially external reinforcement structure 44A. Thus, each first stiffening element 54A is anchored in the first bead 32A by extending into the first bead 32A from the first radially internal anchor point 56A. Each first stiffening element 54A is anchored in the apex 12 by extending into the apex 12 from the first radially external anchor point 58A.

[0172] Each second stiffening element 54B passes through the internal surface 34 at a second radially internal anchor point 56B in the second bead 32B to anchor around the second radially internal reinforcement structure 38B and at a second radially external anchor point 58B in the apex 12 to anchor around the second radially external reinforcement structure 44B. Thus, each second stiffening element 54B is anchored in the second bead 32B by extending into the second bead 32B from the second radially internal anchor point 56B. Each second stiffening element 54B is anchored in the apex 12 by extending into the apex 12 from the second radially external anchor point 58B.

[0173] 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.

[0174] Each second stiffening element 54B comprises a radially internal anchoring portion 542, a portion 544, and a radially external anchoring portion 546, the portion 544 being extended on one side by the radially internal anchoring portion 542 and on the other side by the radially external anchoring portion 546.

[0175] 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.

[0176] 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.

[0177] 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. 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.

[0178] 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.

[0179] The radially external anchorage portion 546 of each second stiffening element 54B extends from the second radially external anchorage point 58B in the apex 12 to anchor around the second radially external reinforcing structure 44B.

[0180] Each first stiffening element 54A forms a first continuous stiffening element which meanders at least from the first bead 32A through the top 12 and each second stiffening element 54B forms a second continuous stiffening element which meanders at least from the second bead 32B through the top 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 top 12 so as to meander from the first bead 32A to the second bead 32B.

[0181] The first radially external anchor point 58A is arranged axially on the same side as the first radially internal anchor point 56A and the first radially internal reinforcing structure 38A with respect to the median plane M. The second radially external anchor point 58B is arranged axially on the opposite side of the second radially internal anchor point 56B and the second radially internal reinforcing structure 38B with respect to the median plane M. Each first and second radially internal anchor point 56A, 56B and external anchor point 58A, 56B is arranged so that portions 543, 544 do not intersect in the toric cavity 36.

[0182] Each first and second stiffening element 54A, 54B is partially wrapped around each first and second circumferential internal radial reinforcement element 40A, 40B respectively.

[0183] Each radially internal anchorage portion 541, 542 extends at least partially axially inside each first and second circumferential axially internal anchoring element 42A, 42B.

[0184] With reference to Figure 2, the tire 10 comprises a first layer of radially inner thermoplastic polymer composition 60A interposed between the stiffening structure 52 and the first radially inner reinforcement structure 38A, more precisely between the radially inner anchoring portion 541 and the first radially inner reinforcement structure 38A, and even more precisely between the radially inner anchoring portion 541 and the first circumferential radially inner reinforcement element 40A. Thus, there is no direct contact between the stiffening structure 52 and the first radially inner reinforcement structure 38A, more precisely between the radially inner anchoring portion 541 and the first radially inner reinforcement structure 38A, and even more precisely between the radially inner anchoring portion 541 and the first circumferential radially inner reinforcement element 40A.

[0185] The first layer of radially internal thermoplastic polymer composition 60A extends from the first stiffening element 54A to the first circumferential radially internal reinforcement element 40A, being in contact with the stiffening structure 52 and the first radially internal reinforcement structure 38A, more precisely with the radially internal anchoring portion 541 and the first radially internal reinforcement structure 38A, and even more precisely with the radially internal anchoring portion 541 and the first circumferential radially internal reinforcement element 40A.With reference to Figure 3, similarly, the tire 10 comprises a second layer of radially internal thermoplastic polymer composition 60B interposed between the stiffening structure 52 and the second radially internal reinforcement structure 38B, more precisely between the radially internal anchoring portion 542 and the second radially internal reinforcement structure 38B and even more precisely between the radially internal anchoring portion 542 and the second circumferential radially internal reinforcement element 40B.Thus, there is no direct contact between the stiffening structure 52 and the second radially internal reinforcement structure 38B, more precisely between the radially internal anchoring portion 542 and the second radially internal reinforcement structure 38B and even more precisely between the radially internal anchoring portion 542 and the second circumferential radially internal reinforcement element 40B.

[0186] The second layer of radially internal thermoplastic polymer composition 60B extends from the second stiffening element 54B to the second circumferential radially internal reinforcement element 40B, being in contact with the stiffening structure 52 and the second radially internal reinforcement structure 38B, more precisely with the radially internal anchoring portion 542 and the second radially internal reinforcement structure 38B, and even more precisely with the radially internal anchoring portion 542 and the second circumferential radially internal reinforcement element 40B.

[0187] With reference to Figure 4, similarly, the tire 10 comprises a first layer of radially external thermoplastic polymer composition 62A interposed between the stiffening structure 52 and the first radially external reinforcement structure 44A, more precisely between the radially external anchoring portion 545 and the first radially external reinforcement structure 44A and even more precisely between the radially external anchoring portion 545 and the first circumferential radially external reinforcement element 46A.Thus, there is no direct contact between the stiffening structure 52 and the first radially external reinforcement structure 44A, more precisely between the radially external anchoring portion 545 and the first radially external reinforcement structure 44A and even more precisely between the radially internal anchoring portion 545 and the first circumferential radially external reinforcement element 46A.

[0188] The first layer of radially external thermoplastic polymer composition 62A extends from the first stiffening element 54A to the first radially external circumferential reinforcing element 46A, being in contact with the stiffening structure 52 and the first radially external reinforcing structure 44A, more precisely with the radially external anchoring portion 545 and the first radially external reinforcing structure 44A, and even more precisely with the radially external anchoring portion 545 and the first radially external circumferential reinforcing element 46A.

[0189] With reference to Figure 5, similarly, the tire 10 comprises a second layer of radially external thermoplastic polymer composition 62B interposed between the stiffening structure 52 and the second radially external reinforcement structure 44B, more precisely between the radially external anchoring portion 546 and the second radially external reinforcement structure 44B and even more precisely between the radially external anchoring portion 546 and the second circumferential radially external reinforcement element 46B.Thus, there is no direct contact between the stiffening structure 52 and the second radially external reinforcement structure 44B, more precisely between the radially external anchoring portion 546 and the second radially external reinforcement structure 44B and even more precisely between the radially internal anchoring portion 546 and the second circumferential radially external reinforcement element 46B.

[0190] The second layer of radially external thermoplastic polymer composition 62B extends from the second stiffening element 54B to the second radially external circumferential reinforcing element 46B, being in contact with the stiffening structure 52 and the second radially external reinforcing structure 44B, more precisely with the radially external anchoring portion 546 and the second radially external reinforcing structure 44B, and even more precisely with the radially external anchoring portion 546 and the second radially external circumferential reinforcing element 46B.

[0191] In the example shown, each first and second layer of radially inner thermoplastic polymer composition 60A, 60B and each first and second layer of radially outer thermoplastic polymer composition 62A, 62B form an encapsulating sheath around each first and second circumferential radially inner reinforcing element 40A, 40B and each first and second circumferential radially inner reinforcing element 44A, 44B. The diameter of each sheathed first and second circumferential radially inner reinforcing element 40A, 40B and of each sheathed first and second circumferential radially inner reinforcing element 44A, 44B is greater than or equal to 1.40 mm, and here equal to 1.50 mm.

[0192] Each first and second layer of thermoplastic polymer composition 60A, 60B and each first and second layer of radially outer thermoplastic polymer composition 62A, 62B comprises a thermoplastic aliphatic polyamide, a polyester or a thermoplastic elastomer and here an aliphatic polyamide 6,6.

[0193] We will now describe, with reference to Figure 6, a tire according to a second embodiment of the invention. Elements analogous to those of the first embodiment are designated by identical reference numerals.

[0194] Unlike the first embodiment example, the first radially inner thermoplastic polymer composition layer 60A of the tire according to the second embodiment example forms a band of thermoplastic polymer composition interposed between the stiffening structure 52 and the first radially inner reinforcement structure 40A.

[0195] The tire according to this second embodiment may also include strips of thermoplastic polymer compositions interposed between the stiffening structure 52 and the second radially internal reinforcement structure 40B as well as interposed between the stiffening structure 52 and each first and second radially external reinforcement structure 44A, 44B and whose characteristics will be deduced mutatis mutandis from those of the strip of thermoplastic polymer composition interposed between the stiffening structure 52 and the first radially internal reinforcement structure 40A.

[0196] Comparative tests

[0197] We tested a tire according to the embodiment example illustrated in figures 1 to 3 and a control tire identical to the tire according to the embodiment example but without a layer of thermoplastic polymer composition.

[0198] 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 in order to cause the degradation of the stiffening structure.

[0199] The test tire completed 20 laps, at the end of which a breakage of several initial stiffening elements in the first bead was observed.

[0200] The tire according to the invention also completed 20 laps without damage, then 5 additional laps after which no breakage of the stiffening elements was observed.

[0201] Thus, the invention has made it possible to significantly improve the endurance of the stiffening structure.

[0202] The invention is not limited to the embodiments described above. It may be envisaged that tires may comprise the first and second radially inner layers of thermoplastic polymer composition 60A, 60B interposed between said stiffening structure 52 and each first and second radially inner reinforcement structure 38A, 38B but no radially outer layer of thermoplastic polymer composition 62A, 62B interposed between the stiffening structure 52 and said or one of said radially outer reinforcement structures 44A, 44B.Tires may be designed comprising first and second radially external thermoplastic polymer layers 62A, 62B, but no first and second radially internal thermoplastic polymer layers 60A, 60B interposed between the stiffening structure 52 and each first and second radially internal reinforcement structure 38A, 38B. Tires may also be designed comprising a first radially internal thermoplastic polymer layer 60A, but no second radially internal thermoplastic polymer layer 60B.

[0203] It will be possible to consider tires having a carcass reinforcement anchored in each first and second bead by a winding of at least one layer of carcass around first and second radially internal circumferential reinforcement elements intended to allow the tire to be attached to a tire mounting support.

[0204] It may be possible to combine the features of the invention described above with anchoring elements as described in application number FR23 15326 and / or with a sealing layer as described in application number FR23 15327 or the absence of a sealing layer as described in application number FR23 15327 and / or primary and supplementary stiffening elements as described in application number FR23 15325 and / or inner and outer layers as described in application number FR23 15328 and / or with anchoring of the radially inner portion of the stiffening elements as described in application number FR2401572 and / or with an irregular circumferential distribution of the stiffening elements as described in application number PCT / FR2024 / 050548 and filed on behalf of theApplicant of this application.

Claims

44 DEMANDS 1. A tire (10) comprising a vertex (12), first and second sidewalls (30A, 30B) each extending radially inward from the vertex (12), 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 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 a stiffening structure (52) extending continuously within the toroidal cavity (36) from at least the first sidewall (30A) and / or bead (32A) to at least the vertex (12), said stiffening structure (52) being anchored at least in the first sidewall (30A) and / or ridge (32A) and / or the summit (12),said stiffening structure (52) being anchored in or around a first radially internal reinforcement structure (38A) of the tire (10) arranged in the first sidewall (30A) and / or bead (32A) and / or in or around one or more radially external reinforcement structure(s) (44A) arranged in the top (12), characterized in that the tire (10) comprises:, - a first layer of radially internal thermoplastic polymer composition (60A) interposed between said stiffening structure (52) and said first radially internal reinforcing structure (38A) and / or, - a radially external thermoplastic polymer composition layer (62A) interposed between said stiffening structure (52) and said or one of said radially external reinforcing structures (44A).

2. Pneumatic (10) according to claim 1, wherein said stiffening structure (52) extends continuously in the toroidal cavity (36) from at least the second flank (30B) and / or bead (32B) to at least the apex (12), said stiffening structure (52) being anchored at least in the second flank (30B) and / or bead 45 (32B), said stiffening structure (52) being anchored in or around a second radially internal reinforcement structure (38B) of the tire (10) arranged in the second sidewall (30B) and / or bead (32B), tire (10) comprising a second radially internal thermoplastic polymer composition layer (60B) interposed between said stiffening structure (54B) and said second radially internal reinforcement structure (38B).

3. A tire (10) according to any one of the preceding claims, wherein the stiffening structure (52) extends in the toroidal cavity (36) from at least the first flank (30A) and / or bead (32A) to at least the apex (12), being anchored in the apex (12), and extends in the toroidal cavity from at least the second flank (30B) and / or bead (32B) to at least the apex (12), being anchored in the apex, said stiffening structure (52) being anchored in or around one or more radially external reinforcing structure(s) (44A) arranged in the apex (12), the tire (10) comprises a radially external thermoplastic polymer composition layer (62A, 62B) interposed between said stiffening structure (52) and said or one of said external radially reinforcing structure(s) (44A).

4. Pneumatic (10) according to any one of the preceding claims, wherein: - said first layer of radially inner thermoplastic polymer composition (60A) is in contact with said stiffening structure (52) and / or said first radially inner reinforcement structure (38A) and / or said layer of radially outer thermoplastic polymer composition (62A) is in contact with said stiffening structure (52) and / or said or one of said radially outer reinforcement structure(s) (44A).

5. Pneumatic (10) according to any one of the preceding claims, wherein said stiffening structure (52) comprises at least a first stiffening element (54A) comprising: 46 - a radially internal anchoring portion (541) extending into the first flank (30A) and / or bead (32A), said first radially internal thermoplastic polymer composition layer (60A) being interposed between said first radially internal reinforcing structure (38A) and the radially internal anchoring portion (541) of said first stiffening element (54A), and / or - a radially external anchoring portion (545) extending into the top (12), said radially external thermoplastic polymer composition layer (62A) being interposed between said or one of said radially external reinforcing structure(s) (44A) and the radially external anchoring portion (545) of said first stiffening element (54A).

6. Pneumatic (10) according to claim 5, wherein: - said first layer of radially inner thermoplastic polymer composition (60A) is in contact with the radially inner anchoring portion (541) of said first stiffening element (54A) and / or of said first radially inner reinforcing structure (38A), and / or said layer of radially outer thermoplastic polymer composition (62A) is in contact with the radially outer anchoring portion (545) of said first stiffening element (54A) and / or of said or one of said radially outer reinforcing structure(s) (44A).

7. Pneumatic (10) according to any one of claims 1 to 6, wherein: - said first radially internal reinforcing structure (38 A) comprising a first circumferential radially internal reinforcing element (40 A), said first layer of radially internal thermoplastic polymer composition (60 A) forms a sheath of said first circumferential radially internal reinforcing element (40 A), and / or - said or one of said radially external reinforcing structure(s) (44A) comprising a circumferential radially external reinforcing element (46A), said polymer composition layer radially external thermoplastic (62A) forms a sheath of said radially external circumferential reinforcing element (46A).

8. Pneumatic (10) according to any one of claims 1 to 6, wherein: - said first layer of radially inner thermoplastic polymer composition (60A) forms a band of thermoplastic polymer composition interposed between said stiffening structure (52) and said first radially inner reinforcement structure (38A) and / or said layer of radially outer thermoplastic polymer composition (62A) forms a band of thermoplastic polymer composition interposed between said stiffening structure (52) and said or one of said radially outer reinforcement structure(s) (44A).

9. Pneumatic (10) according to any one of the preceding claims, wherein: - the first radially internal reinforcement structure (38A) comprises a first circumferential radially internal reinforcement element (40A), and / or - the or at least one of the radially external reinforcement structures (44A, 44B) includes a circumferential radially external reinforcement element (46A, 46B).

10. Pneumatic (10) according to the preceding claim, wherein: - the first circumferential internal radial reinforcement element (40A) comprises a metallic wire reinforcement element, and / or - said external radially external circumferential reinforcing element (46A, 46B) includes a metallic wire reinforcing element.

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