Tires with durable reinforcement structure

Abstract

The tire (10) comprises a crown (12), two sidewalls (30A, 30B), two beads (32A, 32B), an inner surface (33) defining a torus-shaped cavity (35), and a stiffening structure (50) comprising a stiffening element (52) extending continuously within the torus-shaped cavity (35) from at least one of the sidewalls (30A, 30B) or one of the beads (32A, 32B) to the crown (12). The stiffening elements (52) are secured to or around radially inner reinforcing structures (60A, 60B) arranged on the flanks (30A, 30B) and / or the beads (32A, 32B), which are distinct from the circumferential reinforcing elements (40A, 40B) situated on the same side of the median plane (M) of the tire (10) as the flanks (30A, 30B) and / or the beads (32A, 32B), and from the radially outer reinforcing structures (70A, 70B) arranged in the crown (12).

Description

[Technical field]

[0001] The invention relates in particular to a tire for passenger cars. By tire is meant a pneumatic tire intended to form a cavity by cooperating with a mounting support, for example a rim, this cavity being adapted to be pressurized to a pressure higher than atmospheric pressure. The tire according to the invention has a substantially circular torus-like construction around its main axis, which axis coincides with its axis of rotation. [Background technology]

[0002] Known from the prior art is a tire as described in WO2020 / 128225, intended to be fitted to a passenger vehicle. The tire described comprises a crown extending radially inwards on respective opposite sides of the median surface of the tire near the first and second sidewalls and then near the first and second beads intended to come into contact with a mounting support, for example a rim. Each of the first and second beads comprises a circumferential reinforcing element intended to allow the tire to be attached to a mounting support.

[0003] The tire has an inner surface which defines a torus-shaped expansion cavity of the tire when it is mounted on a mounting support.

[0004] The tire described in WO2020 / 128225 comprises a stiffening structure comprising a first threadline stiffening element extending continuously within a torus-shaped cavity from a first bead to the crown, and a second threadline stiffening element extending continuously within the torus-shaped cavity from a second bead to the crown.

[0005] Each of the first and second threadline stiffening elements is joined to a respective bead from which it extends near a bead interface between the threadline stiffening element and a portion of the inner surface of the bead. In a similar manner, each of the first and second threadline stiffening elements is fastened to the crown of the tire near a crown interface between the threadline stiffening element and a portion of the inner surface of the crown. Each bead and crown interface comprises an elastomer mixture cushion positioned between the threadline stiffening element and a corresponding portion of the inner surface.

[0006] It has been noted that each bead and crown interface is subject to delamination under load, such interfaces being sensitive to cyclic loading that can lead to premature separation of the thread stiffening elements and the inner surface of the bead and / or the inner surface radially inwardly of the crown and thus premature failure of the stiffening structure.

[0007] Other assemblies or tires are also known from the prior art, in particular from WO2019 / 115917, GB2299554, FR3089870, FR2638398, US3010504 or US2005279438. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2020 / 128225 [Patent Document 2] WO2019 / 115917 [Patent Document 3] GB2299554 [Patent Document 4] FR3089870 [Patent Document 5] FR2638398 [Patent Document 6] US3010504 [Patent Document 7] US2005279438 [Patent Document 8] WO2017 / 005713 [Patent Document 9] WO2013 / 017422 [Patent Document 10] WO2017 / 168107 [Patent Document 11] WO2018 / 046376 [Patent Document 12] WO2013 / 182477 [Patent Document 13] WO2010 / 51203 [Patent Document 14] EP2660075 [Patent Document 15] EP1253025 [Patent Document 16] EP1876038 [Patent Document 17] EP3406462 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to improve the durability of stiffening structures. [Means for solving the problem]

[0010] The object of the invention is therefore a tire comprising a crown extending radially inwards near two sidewalls and then near two beads, each bead comprising at least one circumferential reinforcing element intended to enable the tire to be mounted on a mounting support thereof, the tire having an inner surface defining a torus-shaped expansion cavity of the tire and a stiffening structure comprising at least one reinforcing element extending continuously in the torus-shaped cavity from at least one of the sidewalls or the beads at least as far as the crown, the or each reinforcing element being: at least one radially inner stiffening structure arranged on the sidewall and / or bead that is distinct from the or each circumferential reinforcing element located on the same side of the median plane of the tire as the sidewall and / or bead, and at least one radially outer reinforcing structure arranged in the crown; Attached to or around:

[0011] Due to the radially inner and outer reinforcing structure, the or each stiffening element is fixed on the one hand to one of the sidewalls and / or one of the beads and on the other hand to the crown, which allows fastening by fixing the or each stiffening element to the tire. Fastening by fixing of this kind is significantly more robust than the bead and crown interface described in WO2020 / 128225. In fact, the fixing makes it possible to avoid loads and radial and axial slippage during peeling of the or each stiffening element towards the inside of the tire. The durability of the stiffening structure of the tire according to the invention is therefore significantly improved, as shown by the tests carried out and described below.

[0012] By fastening the or each stiffening element to the crown, the or each stiffening element is fixed axially and radially with respect to the part of the crown to which it is fastened. In a similar manner, by fastening the or each stiffening element to the sidewall and / or bead, the or each stiffening element is fixed axially and radially with respect to the part of the sidewall and / or bead to which it is fastened.

[0013] Each of the radially inner and outer reinforcing structures is arranged respectively in the sidewall or bead and in the crown of the tire, i.e. radially inside the inner surface and embedded in the mass of material constituting the sidewall or bead and in the crown, the or each stiffening element being fixed to or around the radially inner reinforcing structure at a radially inner fastening point passing through the inner surface, and fixed to or around the radially outer reinforcing structure at a radially outer fastening point passing through the inner surface. This feature makes it possible in particular to reduce the noise generated by the stiffening structures, this noise being attenuated by the structure of the tire that separates the or each radially inner or outer reinforcing structure from the mounting support.

[0014] According to the invention, the or each stiffening element is fixed to or around the respective radially inner and outer reinforcing structure. That is to say, in a first variant, the or each stiffening element may be fixed to one or both of the radially inner and outer reinforcing structures, i.e. the stiffening element penetrates at least partially into or even completely through the structure, which structure therefore forms a mechanical fixation of the or each stiffening element in the structure. In particular, in the situation where the structure is an assembly of several thread elements, saying that the or each stiffening element is fixed to the structure means, for example, that the or each stiffening element is wound around a certain thread element of the structure so that it passes through the structure itself. In a second variant, the or each stiffening element may be fixed around one or both of the radially inner and outer reinforcing structures, i.e. the or each stiffening element bears against the structure so that the structure absorbs part of the force exerted on the or each stiffening element to fix the structure to the sidewall or the bead and the crown. In particular, in the situation where the structure is an assembly of multiple thread elements, stating that the or each stiffening element is secured around the structure means, for example, that the or each stiffening element is wrapped around the peripheral thread elements of the structure without passing through them.

[0015] According to the invention, the or each radially inner reinforcing structure is differentiated from the or each circumferential reinforcing element located on the same side of the median plane of the tire, which makes it possible to very significantly reduce the transmission of the noise generated by the stiffening structure from the or each circumferential reinforcing element to the vehicle through the mounting support of the tire. In fact, the inventor behind the invention hypothesized that the noise generated by the stiffening structure is attenuated by the structure of the tire that separates it from the circumferential reinforcing elements intended to allow the tire to be attached to its mounting support. This attenuation is the result of the fact that the or each radially inner reinforcing structure, due to being differentiated from the or each circumferential reinforcing element located on the same side of the median plane of the tire, is mechanically decoupled from the or each circumferential reinforcing element located on the same side of the median plane of the tire. In other words, the or each radially inner reinforcing structure and the or each circumferential reinforcing element located on the same side of the median plane of the tire are physically separated from each other by one or more separating materials, for example elastomeric materials, allowing the mechanical disconnection of one from the other.

[0016] The toroidal expansion cavity is intended to be pressurized by inflation gas when the tire is mounted on a mounting support, most often a rim.

[0017] Among other advantages, the stiffening structure makes it possible to simultaneously improve the radial, axial and cornering stiffness of the tire compared to classic tires without stiffening structures, but also to tires with other stiffening structures, such as those described in WO2017 / 005713. The radial stiffness is the radial force, expressed in daN / mm, generated by the tire when subjected to a radial displacement equal to 1 mm. The axial stiffness is the axial force, expressed in daN / mm, generated by the tire when subjected to an axial displacement equal to 1 mm. The cornering stiffness is the axial force, expressed in daN / °, generated by the tire when rolling at an angle of 1° around the radial axis.

[0018] By increasing the radial stiffness, the stiffening structure reduces the radial deformation of the crown during rolling, in particular the counterflexion, i.e. the radial deformation on the side opposite to the contact area of ​​the tread that is in contact with the ground. Thus, during the tire rolling around the wheel, the stiffening structure makes it possible to reduce the amplitude of the cyclic deformation of the tire, in particular the tread, and thus the resulting energy dissipation, thus contributing to a reduction in rolling resistance. Furthermore, the value of the contact area remains unchanged with respect to radial load, so that it is possible to maintain the same grip performance as the tire described in WO2017 / 005713.

[0019] By increasing axial and cornering stiffness, the stiffening structure contributes to improved behavior under lateral loads, for example when cornering, and also makes it possible to increase lateral grip under lateral loads, since the contact patch ensures a more even distribution of contact pressure.

[0020] Moreover, since the stiffening structure is at least partially involved in supporting the load applied to the tire, this applied load is absorbed by the tire and by the stiffening structure jointly due to its tire stiffness and inherent structural stiffness. Thus, when the tire is subjected to a nominal radial load, the or each stiffening element located on the opposite side of the contact area is under tension. Conversely, in some embodiments, the or each stiffening element aligned with the contact area undergoes buckling in compression.

[0021] The presence of stiffening structures therefore makes it possible to reduce the tire's contribution to load support, and therefore to reduce the structural stiffness of the tire, for example by reducing the volume of the beads. In fact, the beads of a classic tire dissipate a significant amount of energy due to their volume and the hysteretic properties of the elastomer mixture that comprises them. Reducing the volume of the beads therefore makes it possible to significantly reduce the rolling resistance.

[0022] The stiffening elements have an independent mechanical behavior since they are two-by-two independent within the toroidal cavity of the tire, i.e. they are not mechanically interconnected within the toroidal cavity, e.g. they are not interconnected in such a way as to form a net or mesh within the cavity.

[0023] The tire according to the invention has a substantially torus shape about a pivot axis substantially coinciding with the axis of rotation of the tire, which defines three directions conventionally used by those skilled in the art: axial, circumferential and radial.

[0024] Axial means a direction substantially parallel to the tire's axis of rotation, i.e., its axis of rotation. Circumferential means a direction substantially perpendicular to both the axial direction and to the tire's radius (in other words, tangent to a circle about the tire's axis of rotation).

[0025] Radial means any direction along the radius of the tire, i.e., any direction intersecting and substantially perpendicular to the axis of rotation of the tire.

[0026] The median plane of the tire (denoted M) means the plane perpendicular to the axis of rotation of the tire, located axially midway between the two beads and passing through the axial centre of the crown reinforcement.

[0027] The equatorial circumferential plane (designated E) of a tire means the plane passing through the tire's equator, perpendicular to the median plane and to the radial direction in a meridian section. The equator of a tire is the axis parallel to the tire's axis of rotation in a meridian section (a plane perpendicular to the circumferential direction and parallel to the radial and axial directions) and equidistant between the radially outermost point of the tread intended to be in contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example the rim.

[0028] Median plane means the plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0029] Radially inner, respectively radially outer, means closer to, respectively further from, the axis of rotation of the tire. Axially inner, respectively axially outer, means closer to, respectively further from, the median plane of the tire.

[0030] By bead is meant the radial part of the tire intended to be able to mount the tire on a mounting support, for example a wheel having a rim. Each bead is therefore intended in particular to be in contact with the hooks of the bead to enable its mounting. The bead is therefore delimited radially inwardly by the radially inner edge of the tire and radially outwardly by an axial straight line segment passing through the radially outermost point of contact with a standard rim in the standard published by the European Tire and Rim Technical Organization (ETRTO) 2020.

[0031] Sidewall means the radial portion of the tire that connects the bead to the crown. The sidewall is bounded radially outward by straight line segments perpendicular to the tire outer surface and passing through a point where the angle between a tangent to the tire outer surface and a straight line segment parallel to the axial direction passing through that point is equal to 30°. In a meridian section, the radially outermost point is taken if there are several points where the angle is equal to 30° in absolute value. The sidewall is bounded radially inward by axial straight line segments passing through the radially outermost point of contact with a standard rim as per the European Tire and Rim Technical Organization (ETRTO) 2020 standard.

[0032] A range of values ​​indicated by the expression "between a and b" denotes a range of values ​​extending from greater than a to less than b (i.e. excluding the limits a and b), whereas a range of values ​​indicated by the expression "from a to b" means a range of values ​​extending from a to b (i.e. including the precise limits a and b).

[0033] The tire of the invention is preferably intended for passenger cars as defined by the meaning of the European Tire and Rim Technical Organisation (ETRTO) 2020 standard. This type of tire has a cross-section characterized in meridian section by a section height H and a nominal section width SW, as defined by the European Tire and Rim Technical Organisation (ETRTO) 2020 standard. The values ​​of SW and H are indicated on the sidewall markings of the tire, for example as defined in the ETRTO Manual 2020.

[0034] Passenger tyres to which the invention can be advantageously applied are preferably such that the ratio H / S, expressed as a percentage, is at most equal to 90, preferably at most equal to 80, more preferably at most equal to 70 and at least equal to 20, preferably at least equal to 30, and the nominal section width SW is preferably at least equal to 115 mm, preferably at least equal to 155 mm, more preferably at least equal to 175 mm and at most equal to 385 mm, preferably at most equal to 315 mm, more preferably at most equal to 285 mm. Furthermore, the diameter D at the hook which defines the diameter of the rim for mounting the tyre is at least equal to 12 inches, preferably at least equal to 16 inches and at most equal to 24 inches, preferably at most equal to 21 inches.

[0035] In a tire with a crown reinforcement and a carcass reinforcement, the crown conventionally comprises a tread intended to come into contact with the ground and a crown reinforcement arranged radially inside the tread. The tire also comprises a carcass reinforcement secured in each bead and extending radially in each sidewall and axially in the crown, radially inside the crown reinforcement. Conventionally, the crown reinforcement comprises at least one crown layer with reinforcing elements. These reinforcing elements are preferably metallic or textile thread elements. The carcass reinforcement is secured in each bead using circumferential reinforcing elements.

[0036] In an embodiment enabling the performance achieved in so-called radial tires as defined by the ETRTO, the carcass reinforcement comprises at least one carcass layer, the or each carcass layer comprising carcass thread line reinforcement elements, each carcass thread line reinforcement element extending substantially in a main direction forming an angle of between 80° and 90° in absolute value with the circumferential direction of the tire.

[0037] In a preferred embodiment, the stiffening structure comprises a plurality of stiffening elements circumferentially distributed within a torus-shaped cavity.

[0038] Therefore, the stiffening structure exerts its function over the entire circumference of the tire.

[0039] A circumferentially distributed arrangement can be obtained by a stiffening structure in which the reinforcing elements are distributed with a constant circumferential pitch over the entire circumference of the tire, by a stiffening structure in which the reinforcing elements are distributed periodically over the entire circumference of the tire or alternatively by a stiffening structure in which the reinforcing elements are distributed randomly over the entire circumference of the tire. In one advantageous embodiment, the or each stiffening element is not airtight with respect to the inflation gas of the tire. The or each stiffening element therefore allows the inflation gas to pass through it. In other words, each stiffening element does not define a secondary cavity under the pressure of the tire. Not airtight means that the stiffening element is permeable to the inflation gas and that the pressure is always uniform in the toroidal cavity, in particular during inflation of the tire.

[0040] To allow a relatively easy to implement manufacturing method, it is very advantageous for the tire to comprise a carcass reinforcement secured to each bead, a crown comprising a crown reinforcement and a tread, the carcass reinforcement extending in each sidewall and in the crown radially inside the crown reinforcement, the or each radially external reinforcing structure being arranged radially inside the carcass reinforcement. In a first embodiment, the or each stiffening element comprises: a first radially inner reinforcing structure arranged in the first sidewall and / or in the first bead, said first radially inner reinforcing structure being distinct from the or each circumferential reinforcing element located on the same side of the median plane of the tire as the first sidewall and / or the first bead; - the or each radially outer reinforcing structure located in the crown; a second radially inner reinforcing structure arranged on a second sidewall and / or on a second bead located on the opposite side of the median plane of the tire from the first sidewall and / or the first bead, said second radially inner reinforcing structure being distinct from the or each circumferential reinforcing element located on the same second side of the median plane of the tire as the second sidewall and / or the second bead; and / or each stiffening element is secured to or around the crown such that the or each stiffening element extends continuously within the crown from the first sidewall and / or first bead to the second sidewall and / or second bead.

[0041] In this first embodiment, the or each stiffening element is continuous between the first and second sidewall or bead, thus facilitating the manufacture of the tire on the one hand, since there is no edge of the reinforcing element fixed to the crown, and on the other hand reducing the risk of slipping of the edge of the reinforcing element located at the crown. The or each stiffening element being continuous also improves the transmission of forces between the first and second sidewall and / or bead, thus distributing them over the whole tire.

[0042] Furthermore, the stiffening structure exerts its function on each side of the median plane of the tire, which makes it possible to achieve a homogeneous behavior of the tire.

[0043] In a preferred variant of the first preferred embodiment, the or each stiffening element comprises: a first radially inner reinforcing structure; - first and second radially outer reinforcing structures in the crown; a second radially inner reinforcing structure; The substrate is secured to or around the substrate.

[0044] In this preferred variant, the tire comprises first and second radially external reinforcing structures that are separate from each other, which allows the weight of the stiffening structure to be reduced and makes it possible to fasten reinforcing elements in the crown. Furthermore, for a given axial width, the use of first and second radially external reinforcing structures makes it possible to limit the permissible stresses in the crown compared to a single radially external reinforcing structure, thereby making it possible to maintain a constant contact area.

[0045] In a second embodiment, the stiffening structure comprises at least a first and a second reinforcing element, the or each first reinforcing element having: a first radially inner reinforcing structure arranged in the first sidewall and / or in the first bead, said first radially inner reinforcing structure being distinct from the or each circumferential reinforcing element located on the same side of the median plane of the tire as the first sidewall and / or the first bead; said or a plurality of radially outer reinforcing structures; affixed to or around the The or each second reinforcing element comprises: a second radially inner reinforcing structure arranged on a second sidewall and / or on a second bead located on the opposite side of the median plane of the tire from the first sidewall and / or the first bead, said second radially inner reinforcing structure being distinct from the or each circumferential reinforcing element located on the same second side of the median plane of the tire as the second sidewall and / or the second bead; said or a plurality of radially outer reinforcing structures; affixed to or around the To that end, the or each first and second reinforcing element extends continuously from the first sidewall and / or first bead and from the second sidewall and / or second bead, respectively, to the crown.

[0046] In this second embodiment, in contrast to the first embodiment, the or each first reinforcing element is distinct from and discontinuous with respect to the or each second reinforcing element.

[0047] In a preferred variant of this second embodiment, the or each first reinforcing element comprises: a first radially inner reinforcing structure; a first radially outer reinforcing structure in the crown; affixed to or around the The or each second reinforcing element comprises: a second radially inner reinforcing structure; a second radially outer reinforcing structure at the crown distinct from the first radially outer reinforcing structure; The substrate is secured to or around the substrate.

[0048] Optionally, the first and second radially outer reinforcing structures are arranged axially on either side of the median plane of the tire, preferably substantially symmetrically with respect to the median plane of the tire, thus improving the axial distribution of the forces exerted by the reinforcing elements on the respective first and second sidewalls and / or beads and on the crown.

[0049] In order to prevent as much as possible axial buckling of the tread and thus maintain a uniform contact patch on the one hand and reduce the risk of deterioration with respect to the crown reinforcement of the tire on the other hand, the or each stiffening element extending from the radially inner reinforcing structure: - radially inner fastening points, through an inner surface of which the or each stiffening element is fastened to or around a radially inner reinforcing structure; - a radially outer fastening point, by which the or each stiffening element passes through an inner surface and is fastened to or around the or one of the radially outer reinforcing structures; and a portion extending within the torus-shaped cavity between the radially outer and radially inner anchoring points, the radially outer and inner anchoring points being axially disposed on the same side of the median plane of the tire.

[0050] In the case of a first embodiment, the or each stiffening element comprises: a first radially inner fastening point through which the or each stiffening element passes through an inner surface and is fastened to or around a first radially inner reinforcing structure; - a first radially outer fastening point at which the or each stiffening element passes through an inner surface and is fastened to or around the or each radially outer reinforcing structure; a portion extending within the torus-shaped cavity between The or each stiffening element is - a second radially inner fastening point through which the or each stiffening element passes through an inner surface and is fastened to or around a second radially inner reinforcing structure; - a second radially outer fastening point at which the or each stiffening element passes through an inner surface and is fastened to or around the or each radially outer reinforcing structure; a portion extending within the torus-shaped cavity between Each of the first and second radially inner fastening points and the first and second radially outer fastening points is - the portion extending between the first radially outer fixation point and the first radially inner fixation point and the portion extending between the second radially outer fixation point and the second radially inner fixation point do not cross over within the torus-shaped cavity; the first radially outer anchoring point and the first radially inner anchoring point are arranged axially on the same side of the median plane of the tire; and the second radially outer fastening point and the second radially inner fastening point are arranged axially on the same opposite side of the median plane of the tire; It is like that.

[0051] Indeed, the sections extending between the first anchoring points located on the same side of the median plane on the one hand and the second anchoring points located on the other side of the median plane on the other hand do not cross over, making it possible to suppress axial buckling of the tread, i.e. axial compression of the tread, especially under conditions of high lateral loads, so that on the one hand the contact patch is kept uniform and on the other hand the risk of deterioration of the crown reinforcement of the tire is reduced, in particular by avoiding compression of the various elements comprising it, such as the fabric and metallic fibrous reinforcing elements of the crown reinforcement.

[0052] In a similar manner, in the case of the second embodiment, the or each first reinforcing element may comprise: a first radially inner fastening point through which the or each first reinforcing element passes through an inner surface and is fastened to or around a first radially inner reinforcing structure; - first radially outer fastening points at which the or each first reinforcing element passes through an inner surface and is fastened to or around the or each radially outer reinforcing structure; a portion extending within the torus-shaped cavity between The or each second reinforcing element comprises: a second radially inner fastening point through which the or each second reinforcing element passes through an inner surface and is fastened to or around a second radially inner reinforcing structure; - second radially outer fastening points at which the or each second reinforcing element passes through an inner surface and is fastened to or around the or each radially outer reinforcing structure; a portion extending within the torus-shaped cavity between Each of the first and second radially inner fixing points and the first and second radially outer fixing points is the first radially outer anchoring point and the first radially inner anchoring point are arranged axially on the same side of the median plane of the tire; the second radially outer fastening point and the second radially inner fastening point are arranged axially on the same opposite side of the median plane of the tire; and - the portion extending between the first radially outer fixation point and the first radially inner fixation point and the portion extending between the second radially outer fixation point and the second radially inner fixation point do not cross over within the torus-shaped cavity; They are arranged as follows.

[0053] Alternatively, whether in the first or second embodiment, it can be envisaged that, on the contrary, the respective radially outer first and second fastening points are arranged such that the portion extending between the first fastening point and the portion extending between the second fastening point cross over in the torus-shaped cavity, and / or that the first radially outer fastening point and the first radially inner fastening point are arranged axially on two different sides of the median plane of the tire, and / or that the second radially outer fastening point and the second radially inner fastening point are arranged axially on two different sides of the median plane of the tire.

[0054] In a preferred variant of the first embodiment, the stiffening structure comprises a plurality of stiffening elements forming a continuous reinforcing element so as to present a boustrophedonic path through the crown between the first sidewall and / or first bead and the second sidewall and / or second bead.

[0055] The robustness of the stiffening structure is therefore further improved by eliminating the edges of the reinforcing element that are fixed to each sidewall or each bead. In this variant, it is therefore possible for one continuous reinforcing element to form the stiffening structure over the entire circumference of the tire. Likewise, it is also possible for several continuous reinforcing elements to each form part of the stiffening structure over a portion of the circumference of the tire. Furthermore, this type of stiffening structure is relatively simple to manufacture, since it uses a single reinforcing element whose laying law can be changed as a function of the different tire dimensions. When using several reinforcing elements that differ from each other, it becomes necessary to adjust their length for each tire dimension.

[0056] In a preferred variant of the second embodiment, the stiffening structure comprises: a plurality of first reinforcing elements forming a first continuous reinforcing element so as to present a boustrophedonic path between the first sidewall and / or the first bead and the crown; a plurality of second reinforcing elements forming a second continuous reinforcing element so as to present a boustrophedonic path between the second sidewall and / or the second bead and the crown; Equipped with.

[0057] Very advantageously, the or each stiffening element is fixed to or around the or each radially inner reinforcing structure at a radially inner fixation point radially positioned at a radial distance of from 0.10×H to 0.50×H, preferably from 0.10×H to 0.35×H, from the radially innermost point of the tyre, passing through the inner surface, where H is the section height of the tyre.

[0058] Thus, the transmission of the noise generated by the stiffening structure from the stiffening structure through the mounting support of the tire to the vehicle is further reduced. Indeed, beyond a radial distance equal to 0.10×H, the radially inner anchoring point is farther from the bead, and in particular from the circumferential reinforcing elements of the bead, for example the bead wires, and the sound waves generated by the stiffening structure are significantly attenuated by the structure of the tire before reaching the circumferential reinforcing elements that comprise the main elements of noise transmission between the tire and the mounting support. Nevertheless, it is preferable that the radially inner anchoring point is at a radial distance that is not too large, since this allows an effective absorption of axial forces through the reinforcing elements between the stiffening structure and the sidewall or bead, thus participating in the improvement of the axial stiffness.

[0059] Very advantageously, the or each stiffening element is fixed to or around the or each radially outer reinforcing structure at a radially outer fixation point axially positioned at an axial distance from the median plane of the tyre at most equal to 0.45×SW, preferably from 0.05×SW to 0.45×SW, where SW is the section width of the tyre, passing through the inner surface.

[0060] Above 0.45×S, the or each stiffening element extends in a direction forming a very small angle with the radial direction, so that its contribution to the axial stiffness and cornering stiffness, respectively, decreases.

[0061] With regard to the stiffening structure, each reinforcing element can be characterized geometrically, in particular by its mean cross section Sm, which is not necessarily the same for all of the reinforcing elements. The mean cross section Sm is the average of the cross sections obtained by the intersection of the reinforcing element with a total cylindrical surface coaxial with the tire and radially contained within the inner toroidal cavity. In the most common situation where the cross section is constant, the mean cross section Sm is the constant cross section of the reinforcing element. The mean cross section Sm has a larger characteristic dimension Dmax and a smaller characteristic dimension Dmin, the ratio R=Dmax / Dmin being called the shape factor. As an example, a reinforcing element with a circular mean cross section Sm with a diameter equal to d has a shape factor R=1, a reinforcing element with a rectangular mean cross section Sm with a length L and a width l has a shape factor R=L / l, and a reinforcing element with an elliptical mean cross section Sm with a major axis D and a minor axis d has a shape factor R=D / d.

[0062] The first preferred type of reinforcing element is called one-dimensional, with a shape factor R at most equal to 3. In other words, a reinforcing element is considered one-dimensional if its mean cross section Sm has a characteristic maximum dimension Dmax equal to at most three times the minimum characteristic dimension Dmin. A one-dimensional reinforcing element can have a mechanical behavior of the threadline type, i.e. it is only subjected to tension and compression forces along its mean line. This is why one-dimensional reinforcing elements are usually called threadline reinforcing elements. Among the components routinely used in the field of tires, a textile threadline element consisting of an assembly of textile elementary monofilaments, or a metal cable consisting of an assembly of metal elementary monofilaments, can be considered as a one-dimensional reinforcing element, since its mean cross section Sm is substantially circular and has a shape factor R equal to 1, therefore less than 3.

[0063] A second type of reinforcing element is called two-dimensional, with a shape factor R at least equal to 3. In other words, a reinforcing element is considered to be two-dimensional if the characteristic maximum dimension Dmax of its mean cross section Sm is at least equal to three times its minimum characteristic dimension Dmin. A two-dimensional reinforcing element may exhibit a membrane-type mechanical behavior, i.e. be subjected to tension or compression forces only within its thickness, which is determined by the characteristic minimum dimension Dmin of its mean cross section Sm. In a first variant, reinforcing elements with a shape factor R at least equal to 3 and at most equal to 50 are called lanyard-type two-dimensional. In a second variant, reinforcing elements with a shape factor R at least equal to 50 are called film-type two-dimensional.

[0064] According to a first structural variant for the reinforcing elements, every reinforcing element comprises a homogenous structure with a single component, which is the simplest structure assumed, for example an elementary monofilament of a single material or a layer of a single material. According to a second structural variant, every reinforcing element comprises a composite structure with at least two components, which is for example an assembly with a plurality of elementary monofilaments or a structure made up of an assembly of at least two elements, such as an assembly of a first layer of a first material and a second layer of a second material.

[0065] With regard to the material or materials constituting the stiffening elements, in a first configuration variant, every stiffening element comprises a single material: for example an elementary monofilament of a single material, or an assembly comprising a number of elementary monofilaments of the same material. In a second configuration variant, every stiffening element comprises at least two materials. In this case, it comprises a composite structure from the material point of view: for example an assembly comprising a monofilament of a first material and a monofilament of a second material different from the first material, or a layer comprising a monofilament or an assembly of monofilaments embedded in a polymer matrix.

[0066] In a highly advantageous embodiment, the or each stiffening element is a thread line stiffening element, preferably a textile thread line stiffening element. The reinforcing thread line elements are preferably identical, i.e. have the same geometrical characteristics and are made of the same material.

[0067] These thread-line stiffening elements are usually called stays. The advantage of using thread-line stiffening elements is that they generate a stiffening structure with low weight and low hysteresis. The use of identical reinforcing thread-line elements allows for a uniform distribution of forces between the stiffening elements.

[0068] When being threads, each thread stiffening element is preferably a fabric. By fabric it is meant that each thread stiffening element is non-metallic and is made of a material selected, for example, from polyester, polyamide, polyketone, polyvinyl alcohol, cellulose, mineral fibres, natural fibres, elastomeric materials or a mixture of these materials. For polyester, mention may be made, for example, of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PBN (polybutylene naphthalate), PPT (polypropylene terephthalate), PPN (polypropylene naphthalate). For polyamide, mention may be made of 4-6,6,6-6 polyamide (nylon), aliphatic polyamides such as 11 or 12, and aromatic polyamides such as aramid. The material is preferably polyester or aliphatic polyamide.

[0069] For example, each textile thread stiffening element is a textile assembly comprising one or more elementary monofilaments, twisted or not. Thus, in one embodiment, there may be an assembly in which the elementary monofilaments are substantially parallel to each other. In another embodiment, there may also be an assembly in which the elementary monofilaments are spirally wound. In yet another embodiment, each thread stiffening element comprises an elementary monofilament. Each elementary monofilament has a diameter of 5 μm to 0.80 mm.

[0070] In a first variant, each textile thread stiffening element comprises one or more multi-fiber plies, each comprising a plurality of monofilaments having a diameter of 5 μm to 20 μm. In this first variant, the number of monofilaments in each multi-fiber ply is generally between 100 and 10,000. To prevent leakage of the inflation gas through the capillaries present between the monofilaments of the textile thread stiffening element according to this first variant, each textile thread stiffening element can advantageously be coated, for example with one or more polymer compositions known to the skilled person, so as to block said capillaries. In a second variant, each textile thread stiffening element comprises a multi-fiber ply, each comprising a plurality of monofilaments wound in a spiral and each having a diameter of 0.10 mm to 0.80 mm. In this second variant, the number of monofilaments is generally between 2 and 10. In this second variant, the number of capillaries between the monofilaments is low, so that coating the textile thread stiffening element is of no use, even though it can of course be envisaged.

[0071] Each textile thread stiffening element is conventionally coated with at least one water-based adhesive, for example an RFL type adhesive or as described in documents WO2013 / 017422, WO2017 / 168107.

[0072] In another embodiment, each stiffening element is metallic, e.g., an assembly of metal filaments, each metal filament typically having a size of less than 50 μm, e.g., 10 μm. In one embodiment, each stiffening element comprises an assembly of a plurality of metal filaments. In another embodiment, each stiffening element comprises a metal filament.

[0073] In a variant allowing the tire to be manufactured using a relatively simple method, the thread line stiffening elements advantageously extend continuously in the toroidal cavity from the sidewall or bead to the crown in a main direction which forms an angle of between 85° and 90° in absolute value with the circumferential direction of the tire. In another variant allowing the tire to be manufactured using a more complex method but allowing an increase in the circumferential stiffness, the or each thread line stiffening element extends in the toroidal cavity from the sidewall or bead to the crown in a main direction which forms an angle of between 45° and 75° in absolute value with the circumferential direction of the tire, as described in particular in WO2020 / 128225.

[0074] In one embodiment the or each radially inner reinforcing structure and / or the or each radially outer reinforcing structure comprises at least one thread line stiffening element extending in a main direction which forms an angle with the circumferential direction of the tyre that is smaller than or equal to 10°, preferably smaller than or equal to 5°, more preferably substantially zero.

[0075] Since the tire has a substantially torus shape around the pivot axis, the thread stiffening elements of the radially inner reinforcing structure are optionally wrapped circumferentially around the pivot axis over at most two complete turns, preferably over at most one complete turn.

[0076] It can therefore be envisaged that the thread wire reinforcement elements of the radially inner reinforcing structure are rings without free ends, because they are abutted together, for example, by a sleeve or because the ring is of one-piece construction. It can also be envisaged that the thread wire reinforcement elements of the radially inner reinforcing structure have two free ends.

[0077] The thread reinforcement elements of the radially inner circular structure are preferably made of metal, which in some embodiments advantageously allows the use of the same metal thread reinforcement elements as those used to manufacture the circumferential reinforcement elements.

[0078] In one embodiment, since the tire has a substantially torus shape about the pivot axis, the thread line reinforcement elements of the or each radially outer reinforcing structure are wound circumferentially over at least two complete turns and up to ten complete turns about the pivot axis.

[0079] Thus, like the thread wire reinforcement elements of the radially inner reinforcement structure, the thread wire reinforcement elements of the radially outer reinforcement structure can also be envisaged as rings without free ends, because they are abutted together, for example, by a sleeve or because the ring is of one-piece construction. It can also be envisaged that the thread wire reinforcement elements of the radially outer reinforcement structure have two free ends.

[0080] The thread reinforcement elements of the radially outer circular structure are of textile construction, which makes it possible to avoid localized stiffening of the crown, thus maintaining a correct flattening of the tread in contrast to the situation in which the thread reinforcement elements of the radially outer circular structure are made of metal. Textile thread reinforcement elements that exhibit a relatively low thermal shrinkage are preferred.

[0081] The or each reinforcing element is optionally at least partially wrapped around the or each thread line reinforcing element.

[0082] The thread reinforcement element is at least partially wrapped around the thread reinforcement element so that the direction in which the reinforcement element extends through the torus-shaped cavity is not collinear with the direction in which the reinforcement element extends at the sidewall or bead and crown.

[0083] In a fourth embodiment, the stiffening structure comprises at least one axially inner anchoring stiffening element and at least one axially outer anchoring stiffening element, each of the inner and outer axially anchoring stiffening elements extending continuously in the torus-shaped cavity from at least one of the side walls and / or at least one of the beads to the crown, The or each axially inner fixation stiffening element is a radially inner fixing reinforcing structure of the or each axially inner fixing stiffening element, located on one of the sidewalls and / or on one of the beads, which is distinct from the or each circumferential reinforcing element located on the same side of the median plane of the tire as this sidewall and / or this bead; at least one radially outer anchoring reinforcing structure of the or each axially inner anchoring stiffening element arranged in the crown; affixed to or around The or each axially inner fixation stiffening element is - radially inner anchoring points through which the or each axially inner anchoring stiffening element passes through an inner surface to be anchored to or around a radially inner anchoring reinforcing structure of the or each axially inner anchoring stiffening element; - radially outer anchoring points by which the or each axially inner anchoring stiffening element passes through an inner surface to be anchored to or around one or more radially outer anchoring reinforcing structures of the or each axially inner anchoring stiffening element; a portion extending within the torus-shaped cavity between The or each axially outer fastening stiffening element is a radially inner fixing reinforcing structure of the or each axially outer fixing stiffening element, arranged on the same sidewall and / or on the same bead as the radially inner reinforcing structure to which it is fixed, said radially inner fixing reinforcing structure of the or each axially outer fixing stiffening element being distinct from said or each circumferential reinforcing element located on the same side of the median plane of the tire as said sidewall and / or said bead; at least one radially outer anchoring reinforcing structure of the or each axially outer anchoring stiffening element arranged in the crown; affixed to or around The or each axially outer fastening stiffening element is - radially inner anchoring points through which the or each axially outer anchoring stiffening element passes through an inner surface to be anchored to or around a radially inner anchoring reinforcing structure of the or each axially outer anchoring stiffening element; - radially outer fastening points, by which the or each axially outer fastening stiffening element passes through an inner surface and is fastened to or around one or more radially outer fastening reinforcing structures of the or each axially outer fastening stiffening element; a portion extending within the torus-shaped cavity between The radially outer fastening point of the or each axially inner fastening stiffening element is arranged axially inwardly with respect to the radially outer fastening point of the or each axially outer fastening stiffening element.

[0084] The expression inner or outer anchoring element is used because of the axial offset with respect to the radially outer anchoring point of each reinforcing element in the crown, so that for a given stiffening element it is an axially outer anchoring element because its anchoring point in the crown is axially further from the median plane of the tire than another axially inner anchoring element whose anchoring point in the crown is axially closer to the median plane of the tire.

[0085] The radially outer bond points are preferably on the same side of the median plane of the tire.

[0086] In a variant of the fourth embodiment, the radially inner fastening point of the or each axially inner fixing stiffening element and the radially inner fastening point of the or each axially outer fixing stiffening element are radially and axially aligned on the same circumferential line. In another variant of the fourth embodiment, as envisaged in the fifth embodiment described below, the radially inner fastening point of the or each axially inner fixing stiffening element and the radially inner fastening point of the or each axially outer fixing stiffening element are radially offset with respect to each other.

[0087] In a variant of the fourth embodiment, the respective radially inner and outer fastening points of the or each axially inner fixing stiffening element are in the same meridian section as the respective radially inner and outer fastening points of the or each axially outer fixing stiffening element. In another variant of the fourth embodiment, the respective radially inner and outer fastening points of the or each axially inner fixing stiffening element are in a different meridian section than the respective radially inner and outer fastening points of the or each axially outer fixing stiffening element.

[0088] In one configuration of the fourth embodiment, the or each axially inner anchoring stiffening element comprises: a first radially inner anchoring reinforcing structure of the or each axially inner anchoring stiffening element in the first sidewall and / or in the first bead, which is distinct from the or each circumferential reinforcing element located on the same first side of the median plane of the tire as the first sidewall and / or the first bead; at least one radially outer anchoring reinforcing structure of the or each axially inner anchoring stiffening element in the crown; a second radially inner anchoring reinforcing structure of the or each axially inner anchoring stiffening element in a second sidewall and / or in a second bead, which is located on the other side of the first sidewall and / or first bead relative to the median plane of the tire, said second radially inner anchoring reinforcing structure of the or each axially inner anchoring stiffening element being distinct from the or each circumferential reinforcing element which is located on the same second side of the median plane of the tire as the second sidewall and / or second bead; is attached to or around the or each axially internal reinforcing element extends continuously within the crown from the first sidewall and / or the first bead to the second sidewall and / or the second bead; The or each axially inner fixation stiffening element is a first portion extending within the toroidal cavity, a first radially inner anchoring point through which the or each axially inner anchoring stiffening element passes and is anchored to or around a first radially inner anchoring reinforcing structure of the or each axially inner anchoring stiffening element; - a first radially outer anchoring point at which the or each axially inner anchoring stiffening element passes through an inner surface and is anchored to or around one or more radially outer anchoring reinforcing structures of the or each axially inner anchoring stiffening element; a second portion extending within the toroidal cavity, - a second radially inner anchoring point through which the or each axially inner anchoring stiffening element passes and is anchored to or around a second radially inner anchoring reinforcing structure of the or each axially inner anchoring stiffening element; - a second radially outer anchoring point through an inner surface of the or each axially inner anchoring stiffening element to or around one or more radially outer anchoring reinforcing structures of the or each axially inner anchoring stiffening element; and the second portion extending within the torus-shaped cavity between The or each axially outer fastening stiffening element is a first radially inner anchoring reinforcing structure of the or each axially outer anchoring stiffening element in the first sidewall and / or in the first bead, which is distinct from the or each circumferential reinforcing element located on the same first side of the median plane of the tire as the first sidewall and / or the first bead; at least one radially outer anchoring reinforcing structure of the or each axially outer anchoring stiffening element in the crown; a second radially inner anchoring reinforcing structure of the or each axially outer anchoring stiffening element in a second sidewall and / or in a second bead, which is located on the other side of the first sidewall and / or first bead relative to the median plane of the tire, said second radially inner anchoring reinforcing structure of the or each axially outer anchoring stiffening element being distinct from the or each circumferential reinforcing element which is located on the same second side of the median plane of the tire as the second sidewall and / or second bead; is attached to or around the or each axially outer reinforcing element extends continuously within the crown from the first sidewall and / or the first bead to the second sidewall and / or the second bead; The or each axially outer fastening stiffening element is a first portion extending within the toroidal cavity, a first radially inner anchoring point through which the or each axially outer anchoring stiffening element passes and is anchored to or around a first radially inner anchoring reinforcing structure of the or each axially outer anchoring stiffening element; - a first radially outer fastening point through which the or each axially outer fastening stiffening element passes and is fastened to or around one or more radially outer fastening reinforcing structures of the or each axially outer fastening stiffening element; the first portion extending within the torus-shaped cavity between a second portion extending within the toroidal cavity, - a second radially inner anchoring point through which the or each axially outer anchoring stiffening element passes and is anchored to or around a second radially inner anchoring reinforcing structure of the or each axially outer anchoring stiffening element; - a second radially outer anchoring point through an inner surface of the or each axially outer anchoring stiffening element to or around one or more radially outer anchoring reinforcing structures of the or each axially outer anchoring stiffening element; and the second portion extending within the torus-shaped cavity between The first and second radially outer fastening points of the or each axially inner fastening stiffening element are arranged axially inwardly with respect to the first and second radially outer fastening points of the or each axially outer fastening stiffening element.

[0089] Regardless of the configuration of the fourth embodiment, in a variant, the first and second radially inner fastening points of the or each axially inner fastening element and the first and second radially inner fastening points of the or each axially outer fastening element are radially aligned on the same circumferential line. In another variant, as envisaged in the fifth embodiment described below, the first and second radially inner fastening points of the or each axially inner fastening element and the first and second radially inner fastening points of the or each axially outer fastening element are radially offset relative to each other.

[0090] Regardless of the configuration of the fourth embodiment, in a variant, the first and second radially inner and outer fastening points of the or each axially inner fastening stiffening element are in the same meridian section as the first and second radially inner and outer fastening points of the or each axially outer fastening stiffening element, respectively. In another variant, the first and second radially inner and outer fastening points of the or each axially inner fastening stiffening element are in a different meridian section than the first and second radially inner and outer fastening points of the or each axially outer fastening stiffening element, respectively.

[0091] Very advantageously, each of the first and second radially inner fastening reinforcing structures for the or each axially inner fastening stiffening element is each of the first and second radially inner fastening reinforcing structures for the or each axially outer fastening stiffening element, respectively. Alternatively, each of the first and second radially inner fastening reinforcing structures for the or each axially inner fastening stiffening element is separate from the first and second radially inner fastening reinforcing structures for the or each axially outer fastening stiffening element.

[0092] Very advantageously, the radially outer fastening reinforcing structure of the or each axially inner fastening stiffening element is the radially outer fastening reinforcing structure of the or each axially outer fastening stiffening element. Alternatively, the radially outer fastening reinforcing structure of the or each axially inner fastening stiffening element is the radially outer fastening reinforcing structure of the or each axially outer fastening stiffening element.

[0093] In a fifth embodiment, the stiffening structure comprises at least one radially inner anchoring stiffening element and at least one radially outer anchoring stiffening element, each of the radially inner and outer anchoring stiffening elements extending continuously in the torus-shaped cavity from at least one of the side walls and / or at least one of the beads to the crown, The or each radially inner anchoring stiffening element is a radially inner fixing reinforcing structure of the or each radially inner fixing stiffening element on one of the sidewalls and / or on one of the beads, which is distinct from the or each circumferential reinforcing element located on the same side of the median plane of the tire as this sidewall and / or this bead; at least one radially outer anchoring reinforcing structure of the or each radially inner anchoring stiffening element in the crown; affixed to or around the The or each radially inner anchoring stiffening element is - radially inner anchoring points through which the or each radially inner anchoring stiffening element passes through an inner surface to be anchored to or around the radially inner anchoring reinforcing structure of the or each radially inner anchoring stiffening element; - radially outer anchoring points by which the or each radially inner anchoring stiffening element passes through an inner surface to be anchored to or around one or more radially outer anchoring reinforcing structures of the or each radially inner anchoring stiffening element; a portion extending within the torus-shaped cavity between The or each radially outer anchoring stiffening element is a radially inner fixing reinforcing structure of the or each radially outer fixing stiffening element on the same sidewall and / or in the same bead as the radially inner reinforcing structure to which it is fixed, said radially inner fixing reinforcing structure being distinct from said or each circumferential reinforcing element located on the same side of the median plane of the tire as said sidewall and / or said bead; at least one radially outer anchoring reinforcing structure of the or each radially outer anchoring stiffening element in the crown; affixed to or around the The or each radially outer anchoring stiffening element is - radially inner anchoring points by which the or each radially outer anchoring stiffening element passes through an inner surface to be anchored to or around a radially inner anchoring reinforcing structure of the or each radially outer anchoring stiffening element; - radially outer fastening points by which the or each radially outer fastening stiffening element passes through an inner surface to be fastened to or around one or more radially outer fastening reinforcing structures of the or each axially outer fastening stiffening element; a portion extending within the torus-shaped cavity between The radially inner fastening point of the or each radially inner fastening stiffening element is arranged radially inwardly with respect to the radially inner fastening point of the or each radially outer fastening stiffening element.

[0094] The expressions radially inner and outer anchoring elements are used due to the radial offset of the radially inner anchoring points of each reinforcing element on each sidewall and / or each bead, so that a reinforcing element is called a radially outer anchoring element because its anchoring point on each sidewall and / or each bead is radially further from the tire's rotation axis than another radially inner anchoring element, whose anchoring point on the crown is radially closer to the tire's rotation axis.

[0095] The radially outer bond points are preferably on the same side of the median plane of the tire.

[0096] In a variant of the fifth embodiment, the radially outer fastening point of the or each axially inner fastening stiffening element and the radially outer fastening point of the or each axially outer fastening stiffening element are radially and axially aligned on the same circumferential line. In another variant of the fifth embodiment, as envisaged in the above-mentioned fourth embodiment, the radially outer fastening point of the or each radially inner fastening stiffening element and the radially outer fastening point of the or each radially outer fastening stiffening element are axially offset with respect to each other.

[0097] In a variant of the fifth embodiment, each of the radially inner and outer fastening points for the or each radially inner fastening stiffening element is in the same meridian section as each of the radially inner and outer fastening points for the or each radially outer fastening stiffening element. In another variant of the fifth embodiment, each of the radially inner and outer fastening points for the or each radially inner fastening stiffening element is in a different meridian section than each of the first inner and outer fastening points for the or each radially outer fastening stiffening element.

[0098] In one configuration of the fifth embodiment, the or each radially inner anchoring stiffening element comprises: a first radially inner anchoring reinforcing structure of the or each radially inner anchoring stiffening element in the first sidewall and / or in the first bead, which is distinct from the or each circumferential reinforcing element located on the same first side of the median plane of the tire as the first sidewall and / or the first bead; at least one radially outer anchoring reinforcing structure of the or each radially inner anchoring stiffening element in the crown; a second radially inner anchoring reinforcing structure of the or each radially inner anchoring stiffening element in a second sidewall and / or in a second bead, which is located on the other side of the first sidewall and / or first bead relative to the median plane of the tire, said second radially inner anchoring reinforcing structure of the or each radially inner anchoring stiffening element being distinct from the or each circumferential reinforcing element which is located on the same second side of the median plane of the tire as the second sidewall and / or second bead; is attached to or around the or each radially inner anchoring stiffening element extends continuously within the crown from the first sidewall and / or the first bead to the second sidewall and / or the second bead; The or each radially inner anchoring stiffening element is a first portion extending within the toroidal cavity, a first radially inner anchoring point through an inner surface of the or each radially inner anchoring stiffening element to be anchored to or around a first radially inner anchoring reinforcing structure of the or each radially inner anchoring stiffening element; - a first radially outer anchoring point through an inner surface of the or each radially inner anchoring stiffening element to or around one or more axially outer anchoring reinforcing structures of the or each radially inner anchoring stiffening element; the first portion extending within the torus-shaped cavity between a second portion extending within the toroidal cavity, a second radially inner anchoring point through an inner surface of the or each radially inner anchoring stiffening element to be anchored to or around a second radially inner anchoring reinforcing structure of the or each radially inner anchoring stiffening element; - a second radially outer anchoring point where the or each radially inner anchoring stiffening element passes through an inner surface to be anchored to or around one or more radially outer anchoring reinforcing structures of the or each radially inner anchoring stiffening element; and the second portion extending within the torus-shaped cavity between The or each radially outer anchoring stiffening element is a first radially inner anchoring reinforcing structure of the or each radially outer anchoring stiffening element in the first sidewall and / or in the first bead, which is distinct from the or each circumferential reinforcing element located on the same first side of the median plane of the tire as the first sidewall and / or the first bead; at least one radially outer anchoring reinforcing structure of the or each radially outer anchoring stiffening element in the crown; a second radially inner anchoring reinforcing structure of the or each radially outer anchoring stiffening element in a second sidewall and / or in a second bead, which is located on the other side of the first sidewall and / or first bead relative to the median plane of the tire, said second radially inner anchoring reinforcing structure of the or each radially outer anchoring stiffening element being distinct from the or each circumferential reinforcing element which is located on the same second side of the median plane of the tire as the second sidewall and / or second bead; is attached to or around the or each radially outer reinforcing element extends continuously within the crown from the first sidewall and / or the first bead to the second sidewall and / or the second bead; The or each radially outer anchoring stiffening element is a first portion extending within the toroidal cavity, a first radially inner anchoring point through an inner surface of the or each radially outer anchoring stiffening element to be anchored to or around a first radially inner anchoring reinforcing structure of the or each radially outer anchoring stiffening element; - a first radially outer anchoring point at which the or each radially outer anchoring stiffening element passes through an inner surface to be anchored to or around one or more radially outer anchoring reinforcing structures of the or each radially outer anchoring stiffening element; the first portion extending within the torus-shaped cavity between a second portion extending within the toroidal cavity, a second radially inner anchoring point through an inner surface of the or each radially outer anchoring stiffening element to be anchored to or around a second radially inner anchoring reinforcing structure of the or each radially outer anchoring stiffening element; - a second radially outer anchoring point where the or each radially outer anchoring stiffening element passes through an inner surface to be anchored to or around one or more radially outer anchoring reinforcing structures of the or each radially outer anchoring stiffening element; and the second portion extending within the torus-shaped cavity between Each of the first and second radially inner fastening points for the or each radially inner fastening stiffening element is disposed radially inwardly relative to each of the first and second radially inner fastening points for the or each radially outer fastening stiffening element.

[0099] Regardless of the configuration of the fifth embodiment, in a variant, the first and second radially outer fastening points of the or each radially inner fastening element and the first and second radially outer fastening points of the or each radially outer fastening element are axially aligned on the same circumferential line. In another variant, as envisaged in the fourth embodiment described above, the first and second radially outer fastening points of the or each radially inner fastening element and the first and second radially outer fastening points of the or each radially outer fastening element are axially offset relative to each other.

[0100] Regardless of the configuration of the fifth embodiment, in a variant, the first and second radially inner and outer fastening points of the or each radially inner fastening stiffening element are in the same meridian section as the first and second radially inner and outer fastening points of the or each radially outer fastening stiffening element, respectively. In another variant, the first and second radially inner and outer fastening points of the or each radially inner fastening stiffening element are in a different meridian section than the first and second radially inner and outer fastening points of the or each radially outer fastening stiffening element, respectively.

[0101] Very advantageously, each of the first and second radially inner anchoring reinforcing structures for the or each radially inner anchoring stiffening element is each of the first and second radially inner anchoring reinforcing structures for the or each radially outer anchoring stiffening element. Alternatively, each of the first and second radially inner anchoring reinforcing structures for the or each radially inner anchoring stiffening element is distinct from each of the first and second radially inner anchoring reinforcing structures for the or each radially outer anchoring stiffening element.

[0102] Very advantageously, the radially outer fixing reinforcing structure of the or each radially inner fixing stiffening element is the radially outer fixing reinforcing structure of the or each radially outer fixing stiffening element. Alternatively, the radially outer fixing reinforcing structure of the or each radially inner fixing stiffening element is the radially outer fixing reinforcing structure of the or each radially outer fixing stiffening element.

[0103] It is noted that the fourth and fifth embodiments can be combined to differentiate the fastening at the crown and each sidewall and / or each bead, and have radially and axially inner reinforcing elements, or radially and axially outer reinforcing elements, or radially inner and axially outer reinforcing elements, or radially outer and axially inner reinforcing elements.

[0104] In another variation on the or each radially inner reinforcing structure and / or the or each radially outer reinforcing structure, the or each radially inner reinforcing structure and / or the or each radially outer reinforcing structure comprises a woven, knitted or non-woven fabric, preferably a woven or knitted fabric.

[0105] The or each reinforcing element preferably passes through a woven, knitted or non-woven fabric, preferably through a woven or knitted fabric of the or each radially inner reinforcing structure and / or the or each radially outer reinforcing structure.

[0106] In yet another variation of the or each radially inner reinforcing structure, the tire comprises a carcass reinforcement secured to each bead and extending within each sidewall, and the or each radially inner reinforcing structure comprises a portion of the carcass reinforcement extending radially within the sidewall and / or bead.

[0107] In yet another variation of the or each radially external reinforcing structure, the tire comprises a carcass reinforcement extending axially in the crown, and the or each radially external reinforcing structure comprises a portion of the carcass reinforcement extending axially in the crown.

[0108] That is, in one embodiment, the carcass reinforcement comprises carcass thread line reinforcement elements, the or each stiffening element being at least partially wrapped around one or more of the carcass thread line reinforcement elements of the parts of the carcass reinforcement extending axially through the sidewall and / or bead and / or crown.

[0109] Following this general description, the invention will be better understood on reading the following detailed description, given purely by way of non-limiting example and in conjunction with the drawings, in which: [Brief description of the drawings]

[0110] [Figure 1] 1A, 1B and 1C show a tire according to a first embodiment, FIG. 1A being a view in a meridian section parallel to the tire's axis of rotation, and FIGS. 1B and 1C being views of the tire's interior from different directions. [Diagram 2] FIG. 2 is a cutaway view of the tire of FIG. 1 showing the placement of thread line reinforcement elements within the crown. [Diagram 3] FIG. 2 shows the arrangement of stiffening structures with respect to the tire of FIG. 1. [Figure 4] FIG. 1B is a detailed view of zone IV of FIG. 1A. [Diagram 5] FIG. 1B is a detailed view of zone V of FIG. 1A. [Figure 6] FIG. 1B is a view similar to FIG. 1A for a tire according to a second embodiment; [Figure 7] FIG. 1B is a view similar to FIG. 1A for a tire according to a third embodiment. [Figure 8] FIG. 1B is a view similar to FIG. 1A for a tire according to a fourth embodiment. [Figure 9] FIG. 1B is a view similar to FIG. 1A for a tire according to a fifth embodiment. [Figure 10] FIG. 1B is a view similar to FIG. 1A for a tire according to a sixth embodiment. [Figure 11] 11 is a view similar to FIG. 3 for the tire of FIG. 10 according to a sixth embodiment; [Figure 12] 11 is a view similar to FIG. 4 for the tire of FIG. 10 according to a sixth embodiment; [Figure 13] 5 for the tire of FIG. 10 according to a sixth embodiment. FIG. [Figure 14] FIG. 1B is a view similar to FIG. 1A for a tire according to a seventh embodiment. [Figure 15]FIG. 1B is a meridian section parallel to the tire's axis of rotation of the tire of FIG. 1A subjected to a lateral force F; [Figure 16] FIG. 2 is a meridian section parallel to the tire rotation axis for a control tire not according to the invention; [Figure 17] FIG. 1B is a tire contact patch diagram for the tire of FIG. 1A subjected to a lateral force F. [Figure 18] FIG. 2 is a tire contact patch diagram for a control tire not in accordance with the present invention. [Figure 19A] 19A and 19B show a tool and a method for manufacturing a tire according to the first embodiment. [Figure 19B] 19A and 19B show a tool and a method for manufacturing a tire according to the first embodiment. [Figure 20A] 20A and 20B show a tool and a method for manufacturing a tire according to the first embodiment. [Figure 20B] 20A and 20B show a tool and a method for manufacturing a tire according to the first embodiment. [Figure 21] 1 shows a tool and a method for manufacturing a tire according to a first embodiment. [Figure 22A] 22A-22F are diagrams showing a tool and a method for manufacturing a tire according to a first embodiment. [Figure 22B] 22A-22F are diagrams showing a tool and a method for manufacturing a tire according to a first embodiment. [Figure 22C] 22A-22F are diagrams showing a tool and a method for manufacturing a tire according to a first embodiment. [Figure 22D] 22A-22F are diagrams showing a tool and a method for manufacturing a tire according to a first embodiment. [Figure 22E] 22A-22F are diagrams showing a tool and a method for manufacturing a tire according to a first embodiment. [Figure 22F]22A-22F are diagrams showing a tool and a method for manufacturing a tire according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0111] The diagrams relating to a tire depict a system of axes X, Y, Z corresponding respectively to the tire's conventional axial (Y), radial (Z) and circumferential (X) directions.

[0112] A tire according to the invention and designated by the general reference number 10 is represented in Figures 1A, 1B and 1C. The tire 10 has a substantially torus shape about an axis of rotation substantially parallel to an axial direction Y. The tire 10 is intended for passenger cars and has the dimensions 275 / 35ZR19. In the various figures, the tire 10 is represented in new condition, i.e. not yet used.

[0113] The tire 10 comprises a crown 12 including a tread 14 intended to come into contact with the ground when rolling, and a crown reinforcement 16 extending in the crown 12 in a circumferential direction X. The tire 10 also includes a layer 18 that is airtight to inflation gases.

[0114] The crown reinforcement 16 comprises an actuation reinforcement 20 and a wrapping reinforcement 22. The actuation reinforcement 20 comprises at least one working layer, here two working layers 24, 26. In this example, the actuation reinforcement 20 is composed of two working layers 24, 26. The radially inner working layer 24 is arranged radially inward of the radially outer working layer 26.

[0115] The packaging reinforcement 22 includes at least one packaging layer, and here includes one packaging layer 28. Here, the packaging reinforcement 22 includes the packaging layer 28.

[0116] The crown reinforcement 16 radially lies on the tread 14. In this case, the wrapping reinforcement 22, here the wrapping layer 28, is arranged radially outside the operational reinforcement 20 and is therefore sandwiched radially between the operational reinforcement 20 and the tread 14.

[0117] The tire 10 comprises a first and a second sidewall 30A, 30B extending radially inwardly from the crown 12. The second sidewall 30B is located on the opposite side of the median plane M from the first sidewall 30A. The tire 10 further comprises a first and a second bead 32A, 32B extending radially inwardly from each of the first and second sidewalls 30A, 30B, respectively. The second bead 32B is located on the opposite side of the median plane M from the first bead 32A. Each of the first and second sidewalls 30A, 30B connects each of the first and second beads 32A, 32B, respectively, to the crown 12. An inner surface 33 intended to be in contact with the inflation gas of the tire 10 defines a torus-shaped inflation cavity 35 of the tire. Here, the inner surface 33 is carried by the airtight layer 18. Each of the first and second beads 32A, 32B comprises a first and second circumferential reinforcing element 40A, 40B, respectively, here comprising a bead wire enabling attachment of the tire 10 to a mounting support, for example a rim.

[0118] The tire 10 comprises a carcass reinforcement 34 wrapped around first and second circumferential reinforcing elements 40A, 40B, in this case secured in the first and second beads 32A, 32B, respectively. The carcass reinforcement 34 extends radially in each sidewall 30 and radially inside the axial crown reinforcement 16 in the crown 12. The crown reinforcement 16 is arranged radially between the tread 14 and the carcass reinforcement 34. The carcass reinforcement 34 comprises at least one carcass layer, here only one carcass layer 36. In this case, the carcass reinforcement 34 consists of only one carcass layer 36.

[0119] Each of the working layers 24, 26, i.e., the wrap layer 28 and the carcass layer 36, comprises an elastomeric matrix having embedded therein one or more thread reinforcement elements of the corresponding layer, which will now be described with reference to FIG.

[0120] The wrapping reinforcement 22, here the wrapping layer 28, is axially delimited by two axial edges 28A, 28B of the wrapping reinforcement 22. The wrapping reinforcement 22 comprises one or more wrapping thread wire reinforcement elements 280 wound in a spiral manner in the circumferential direction so as to extend axially from the axial edge 28A of the wrapping layer 28 to the other axial edge 28B in the main direction D0 of each wrapping thread wire reinforcement element 280. The main direction D0 forms with the circumferential direction X of the tire 10 an angle AF, in absolute value, less than or equal to 10°, preferably less than or equal to 7°, more preferably less than or equal to 5°. Here, AF=-5°.

[0121] The radially inner working layer 24 is delimited axially by two axial edges 24A, 24B. The radially inner working layer 24 comprises actuating threadline reinforcement elements 240 which extend axially from the axial edge 24A to the other axial edge 24B substantially parallel to each other in the main direction D1. Similarly, the radially outer working layer 26 is delimited axially by two axial edges 26A, 26B. The radially outer working layer 26 comprises actuating threadline reinforcement elements 260 which extend axially from the axial edge 26A to the other axial edge 26B substantially parallel to each other in the main direction D2. The main direction D1 in which each of the working thread line reinforcement elements 240 of the radially inner working layer 24 extends and the main direction D2 in which each of the working thread line reinforcement elements 260 of the other radially outer working layer 26 extends form opposite angles AT1 and AT2, respectively, with the circumferential direction X of the tire 10. Each of the main directions D1, D2 forms an angle AT1, AT2, respectively, with the circumferential direction X of the tire 10 that is strictly greater than 10° in absolute value, preferably between 15° and 50°, more preferably between 20° and 35°. Here, AT1=-26°, AT2=+26°.

[0122] The carcass layer 36 is axially delimited by two axial edges 36A, 36B. The carcass layer 36 comprises carcass thread line reinforcing elements 340 extending axially from its axial edge 36A to the other axial edge 36B in a main direction D3 that forms an angle AC with the circumferential direction X of the tire 10, the angle AC being greater than or equal to 60° in absolute value, preferably between 80° and 90°, here AC=+90°.

[0123] Each wrapping thread reinforcing element 280 conventionally comprises two multifiber plies, one consisting of an aliphatic polyamide monofilament ply, here nylon with a count corresponding to 140 tex, and the other consisting of an aromatic polyamide monofilament ply, here aramid with a count corresponding to 167 tex, advantageously wound with 290 turns per meter in one direction and then wound around each other with 290 turns per meter in the opposite direction. The two multifiber plies are spirally wound around each other. Of course, any other wrapping thread reinforcing element known to the person skilled in the art can also be used.

[0124] Each working threadline reinforcement element 240, 260 is an assembly of four steel monofilaments, comprising an inner layer of two steel monofilaments initially spirally wound with an infinite pitch and an outer layer of two steel monofilaments initially spirally wound with a pitch of 14.3 mm in one direction, the four monofilaments then being wound with a pitch of 14.3 mm in the opposite direction, each steel monofilament having a diameter equal to 0.26 mm. In another variant, each working threadline reinforcement element 240, 260 is made up of a steel monofilament having a diameter equal to 0.30 mm. In yet another variant, each working threadline reinforcement element is an assembly of two monofilaments spirally wound around each other, with a diameter equal to 0.30 mm. More generally, the steel monofilaments have a diameter between 0.25 mm and 0.32 mm. Of course, any other working threadline reinforcement element known to the person skilled in the art can also be used.

[0125] Each carcass thread-line reinforcing element 340 conventionally comprises two multifiber plies, each of which comprises a monofiber ply of polyester, here PET, which are individually spirally wound in one direction with 270 turns per meter and then spirally wound around each other in the opposite direction with 240 turns per meter. Each of these multifiber strands has a count equal to 334 tex. In another variant, a count equal to 144 tex and a twist equal to 420 turns per meter, or a count equal to 220 tex and a twist equal to 270 turns per meter can be used.

[0126] 1A, 1B and 1C, the tire 10 comprises a stiffening structure 50 comprising a plurality of stiffening elements 52 extending continuously in the toroidal cavity 35. The stiffening elements 52 are circumferentially distributed in the toroidal cavity 35. The stiffening elements 52 are preferably circumferentially distributed with a repeating angular pitch of between 1 and 5 degrees (inclusive), more preferably between 1 and 3 degrees (inclusive). As a result, depending on the dimensions of the tire 10, the stiffening structure 50 has between 72 and 360 stiffening elements 52, preferably between 120 and 360 stiffening elements 52, here 240 stiffening elements 52. This number of stiffening elements 52 makes it possible to achieve a good trade-off between, on the one hand, a number of stiffening elements high enough to obtain effective reinforcement of the tire 10, as will be explained below, and, on the other hand, a number of stiffening elements 52 that is moderate enough to allow a corresponding number of passages 1500 to be arranged in the core 1000 without excessively weakening the structure of the core 1000 or complicating its extraction from the mold.

[0127] Each stiffening element 52 is a textile thread reinforcement element and comprises an assembly of three multifiber plies, in this case of polyester, here PET, individually wound with 220 turns per meter in one direction and then wound on each other with 220 turns per meter in the opposite direction, each of these multifiber plies having a thread count equal to 220 tex.

[0128] Each thread stiffening element 52 extends continuously in the crown 12 from the first sidewall 30A and / or the first bead 32A to the second sidewall 30B and / or the second bead 32B, here from the first sidewall 30A to the second sidewall 30B, in the crown 12. The main direction in which each stiffening element 52 extends in the toroidal cavity 35 forms an angle with the circumferential direction X of between 85° and 90° in absolute value.

[0129] The stiffening structure 50 also comprises radially inner first and second reinforcing structures 60A, 60B on the first and second side walls 30A, 30B and / or on the first and second beads 32A, 32B, respectively, here on each of the first and second side walls 30A, 30B, respectively. Each of the radially inner first and second reinforcing structures 60A, 60B is separate from each of the first and second circumferential reinforcing elements 40A, 40B, respectively, which are located on the same side of the median plane as each of the first and second side walls 30A, 30B. In this case, each of the radially inner first and second reinforcing structures 60A, 60B is arranged radially outside each of the first and second circumferential reinforcing elements 40A, 40B, respectively.

[0130] Each of the radially inner first and second reinforcing structures 60A, 60B comprises a first and a second metal thread wire reinforcement element 62A, 62B, respectively, here comprising an assembly of an inner layer of four 0.35 mm metal elementary monofilaments helically wound with a pitch of 5 mm and an outer layer of 0.35 mm metal elementary monofilaments helically wound around the inner layer with a pitch of 10 mm. Each thread wire reinforcement element 62A, 62B extends in a main direction that forms an angle with the circumferential direction X of less than or equal to 10°, preferably less than or equal to 5°, here substantially zero, as can be seen in Figures 3 and 4. For each of the first and second radially inner reinforcing structures 60A, 60B, the first and the second thread wire reinforcement element 62A, 62B is wound in the circumferential direction around the pivot axis Y over a maximum of two complete turns, here a maximum of one complete turn.

[0131] In order to guarantee an optimal fixation of each stiffening element 52, each of the first and second radially inner reinforcing structures 60A, 60B has a relatively high stiffness in tension and in bending. Moreover, in order to still optimize the fixation of each stiffening element 52, each of the first and second radially inner reinforcing structures 60A, 60B is embedded in one or more masses of preferably elastomeric material, the nominal secant modulus of elasticity at 10% elongation being greater than or equal to 20 MPa, preferably greater than or equal to 30 MPa, here equal to 56 MPa. Its measurement is carried out in accordance with French standard NF T 46-002 (September 1988). The nominal secant modulus of elasticity (or apparent stress in MPa), calculated at 10% elongation on the initial cross section of the specimen, is measured during the second elongation (i.e. after acceptance). The tensile measurements are carried out under normal conditions of temperature (23±2° C.) and relative humidity (50±5%) in accordance with French standard NF T 40-101 (December 1979).

[0132] The stiffening structure 50 further comprises first and second radially outer reinforcing structures 70A, 70B in the crown 12. The first and second radially outer reinforcing structures 70A, 70B are arranged axially on either side of the median plane M of the tire 10, here substantially symmetrically with respect to the median plane M of the tire 10. Each of the radially outer reinforcing structures 70A, 70B is arranged radially inward of the carcass reinforcement 34.

[0133] The first and second radially outer reinforcing structures 70A, 70B respectively comprise a first and a second textile thread reinforcement element 72A, 72B, in this case comprising an assembly of two multifiber plies, each composed of an aromatic polyamide monofilament ply, here aramid with a count corresponding to 330 tex, and one multifiber ply composed of an aliphatic polyamide monofilament ply, here nylon with a count corresponding to 188 tex, each of which is individually spirally wound with 270 turns per meter in one direction and then spirally wound around each other with 270 turns per meter in the opposite direction. These three multifiber strands are spirally wound around each other. Each of the thread reinforcement elements 72A, 72B extends in a main direction that forms an angle with the circumferential direction X that is less than or equal to 10°, preferably less than or equal to 5°, here substantially zero, as can be seen in Figures 3 and 5. For each of the first and second radially outer reinforcement structures 70A, 70B, the first and second thread reinforcement elements 72A, 72B are wound circumferentially around the pivot axis Y for at least two complete turns and up to ten complete turns, here up to four complete turns around the pivot axis.

[0134] To ensure optimal anchoring of each stiffening element 52, each of the first and second radially external reinforcing structures 70A, 70B has a relatively high stiffness in tension and a relatively low stiffness in flexion, limiting over-envelopment of the crown 12 without the risk of reducing the flatness of the tread 14. Moreover, to still optimize the anchoring of each stiffening element 52, each of the first and second radially external reinforcing structures 70A, 70B is embedded in one or more masses of preferably elastomeric material, the nominal secant modulus of elasticity at 10% elongation being greater than or equal to 2.5 MPa, preferably less than or equal to 15 MPa, more preferably less than or equal to 10 MPa, more preferably less than or equal to 5 MPa, here equal to 3 MPa.

[0135] Each stiffening element 52 is secured in the first sidewall 30A around the first radially inner reinforcing structure 60A and in the second sidewall 30B around the second radially inner reinforcing structure 60B. Here, each stiffening element 52 is at least partially wrapped around each of the first and second threadline reinforcement elements 62A, 62B. Each stiffening element 52 is also secured in the crown 12 around each of the first and second radially outer reinforcing structures 70A, 70B. Here, each stiffening element 52 is at least partially wrapped around each of the first and second threadline reinforcement elements 72A, 72B.

[0136] Each stiffening element 52 passes through the inner surface 33 at a first radially inner anchoring point 54A secured about the first radially inner reinforcing structure 60A and a first radially outer anchoring point 56A secured about the first radially outer reinforcing structure 70A. The stiffening elements 52 pass through the inner surface 33 at a second radially inner anchoring point 54B secured about the second radially inner reinforcing structure 60B and a second radially outer anchoring point 56B secured about the second radially outer reinforcing structure 70B.

[0137] Each stiffening element 52 thus comprises a portion 521, 522 embedded in each side wall 30A, 30B, respectively, first and second portions 523, 524 extending within the torus-shaped cavity 35 between the first radially inner fixation point 54A and the first radially outer fixation point 56A and between the second radially inner fixation point 54B and the second radially outer fixation point 56B, respectively, and a portion 525 embedded in the crown 12 between the first and second portions 523, 524.

[0138] To ensure optimal fixation of each stiffening element, each portion 521, 522 has a relatively long length, here 20 mm or more, and is joined to a length of 1 mm or more of each radially inner reinforcing structure 60A, 60B.

[0139] 1A, the first radially outer fastening point 56A is axially on the same side as the first radially inner fastening point 54A and the first radially inner structure 60A with respect to the median plane M. The second radially outer fastening point 56B is axially on the same side as the second radially inner fastening point 54B and the second radially inner structure 60B with respect to the median plane M. Each of the first and second radially inner fastening points 54A, 54B and the first and second radially outer fastening points 56A, 56B are positioned such that the first and second portions 523, 524 do not cross over within the torus-shaped cavity 35.

[0140] Each of the first and second radially outer anchoring points 56A, 56B is at a respective axial distance D1, D2 from the median plane M of the tire 10 of at most 0.45×SW, preferably 0.05×SW to 0.45×SW, SW being the nominal section width of the tire 10. The nominal section width is as defined in the ETRTO 2020 standard manual and can in particular be found in a marking made on at least one of the sidewalls 30A, 30B of the tire 10 in the form SW / ARαVUβ, where SW designates the nominal section width, AR designates the nominal aspect ratio, α designates the construction and is R or ZR, V designates the nominal rim diameter, U designates the load index and β designates the speed rating, where D1=D2=45 mm.

[0141] Each of the first and second radially inner fixation points 54A, 54B is at a respective radial distance B1, B2 from the radially innermost point of the tire 10 of 0.10×H to 0.50×H, preferably 0.10×H to 0.35×H, where H is the tire's section height defined by H=SW×AR / 100, where SW is the nominal section width and AR is the nominal aspect ratio of the tire according to the ETRTO 2020 standard manual. The nominal section width SW and the nominal aspect ratio AR are those found in the dimensional markings on the tire's sidewall and according to the ETRTO 2020 standard manual. Here, B1=B2=30 mm.

[0142] 3 and 4, the stiffening elements 52 form a continuous reinforcing element so as to present a boustrophedonic path between the first side wall 30A and the second side wall 30B within the crown 12. Alternatively, separate and therefore discontinuous stiffening elements 52 can be envisaged as well.

[0143] Figure 6 shows a tire according to a second embodiment of the invention, elements which are similar to those according to the first embodiment are designated with the same reference numbers.

[0144] Unlike the tire according to the first embodiment, the stiffening structure 50 of the tire 10 according to the second embodiment comprises first and second stiffening elements 52A, 52B that are separate from each other. Each stiffening element 52A is fixed around a first radially inner reinforcing structure 60A arranged on the first sidewall 30A and around a first radially outer reinforcing structure 70A arranged on the crown 12. Each second stiffening element 52B is fixed around a second radially inner reinforcing structure 60B arranged on the second sidewall 30B and around a second radially outer reinforcing structure 70B arranged on the crown 12, such that each first stiffening element 52A extends continuously in the torus-shaped cavity 35 from the first sidewall 30A to the crown 12, and each second stiffening element 52B extends continuously in the torus-shaped cavity 35 from the second sidewall 30B to the crown 12.

[0145] The first stiffening element 52A forms a first continuous reinforcing element to present a boustrophedonic path between the first sidewall 30A and the crown 12. The second stiffening element 52B forms a second continuous reinforcing element to present a boustrophedonic path between the second sidewall 30B and the crown 12.

[0146] Each of the first and second stiffening elements 52A, 52B comprises a first and second portion 521A, 521B embedded in the first and second side walls 30A, 30B, respectively, a first and second portion 523A, 524B extending in the torus-shaped cavity 35 between the first radially inner and first radially outer fastening points 54A, 56A and between the second radially inner and second radially outer fastening points 54B, 56B, respectively, and a first and second portion 525A, 525B embedded in the crown 12. For clarity, in FIG. 6, a part 523A', 523B' of each of the first and second portions of the stiffening elements 52A', 52B' is depicted outside the meridian section of FIG. 6, although it is continuous with each of the first and second stiffening elements 52A, 52B.

[0147] As in the first embodiment, the first radially outer fastening point 56A is axially on the same side of the median plane M as the first radially inner fastening point 54A and the first radially inner structure 60A. The second radially outer fastening point 56B is axially disposed on the same side of the median plane M as the second radially inner fastening point 54B and the second radially inner structure 60B. Each of the first and second radially inner fastening points 54A, 54B and the radially outer fastening points 56A, 56B are positioned such that the first and second portions 523A, 523B do not cross over within the torus-shaped cavity 35.

[0148] In a variant of the second embodiment not shown, an embodiment can be envisaged which is similar to the second embodiment, but in which the stiffening structure 50 does not comprise two radially outer reinforcing structures, but rather a single radially outer reinforcing structure, as in the case of the third embodiment described below.

[0149] Figure 7 shows a tire according to a third embodiment of the invention, elements which are similar to those of the tire according to the conventional embodiment are designated with the same reference numbers.

[0150] Unlike the tire according to the first embodiment, the stiffening structure of the tire 10 according to the third embodiment comprises a single radially outer reinforcing structure 73. Each stiffening element 52 is secured around the first radially inner reinforcing structure 60A, around the radially outer reinforcing structure 73 in the crown 12 and around the second radially inner reinforcing structure 60B so as to extend continuously within the crown 12 from the first sidewall 30A to the second sidewall 30B.

[0151] Figure 8 shows a tire according to a fourth embodiment of the invention. Elements similar to those of the tire according to the conventional embodiment are designated with the same reference numbers.

[0152] Unlike the first embodiment, the stiffening structure 50 comprises an axially outer anchoring stiffening element 52 and an axially inner anchoring stiffening element 53. The stiffening structure 52 comprises first and second radially outer reinforcing structures 70A, 70B arranged on either side of the median plane M and substantially symmetrical with respect to the median plane M.

[0153] Each axially outer anchoring stiffening element 52 is secured around the first radially inner reinforcing structure 60A, around the first and second radially outer reinforcing structures 70A, 70B, and around the second radially inner reinforcing structure 60B such that it extends continuously within the crown 12 from the first sidewall 30A to the second sidewall 30B. Each axially outer anchoring stiffening element 52 comprises a first portion 523 extending within the torus-shaped cavity 35 between a first radially inner anchoring point 54A, where each axially outer anchoring stiffening element 52 passes through the inner surface 33 and is secured around the first radially inner reinforcing structure 60A, and a first radially outer anchoring point 56A, where each axially outer anchoring stiffening element 52 passes through the inner surface 33 and is secured around the first and second radially outer reinforcing structures 70A, 70B. Each axially outer fixing stiffening element 52 has a second portion 524 extending within the torus-shaped cavity 35 between a second radially inner fixing point 54B, at which each axially outer fixing stiffening element 52 passes through the inner surface 33 and is fixed around the second radially inner reinforcing structure 60B, and a second radially outer fixing point 56B, at which each axially outer fixing stiffening element 52 passes through the inner surface 33 and is fixed around the first and second radially outer reinforcing structures 70A, 70B.

[0154] Each axially inner anchoring stiffening element 53 is secured around the first radially inner reinforcing structure 60A, around the first and second radially outer reinforcing structures 70A, 70B and around the second radially inner reinforcing structure 60B such that each second stiffening element 53 extends continuously from the first sidewall 30A to the second sidewall 30B within the crown 12. Each axially inner anchoring stiffening element 53 comprises a first portion 533 extending within the torus-shaped cavity 35 between a first radially inner anchoring point 55A, where each axially inner anchoring stiffening element 53 passes through the inner surface 33 and is secured around the first radially inner reinforcing structure 60A, and a first radially outer anchoring point 57A, where each axially inner anchoring stiffening element 53 passes through the inner surface 33 and is secured around the first and second radially outer reinforcing structures 70A, 70B. Each axially inner fixing stiffening element 53 has a first portion 534 extending within the torus-shaped cavity 35 between a second radially inner fixing point 55B, at which each axially inner fixing stiffening element 53 passes through the inner surface 33 and is fixed around the second radially inner reinforcing structure 60B, and a second radially outer fixing point 57B, at which each axially inner fixing stiffening element 53 passes through the inner surface 33 and is fixed around the first and second radially outer reinforcing structures 70A, 70B.

[0155] In a manner similar to the first embodiment, the first and second radially inner fastening points 54A, 55A, 54B, 55B and the first and second radially outer fastening points 56A, 57A, 56B, 57B for each axially inner and axially outer fastening element 53, 52 are arranged such that the portions 533 and 534 do not cross over in the torus-shaped cavity and the portions 523 and 524 do not cross over in the torus-shaped cavity, the first radially outer fastening points 56A, 57A and the first radially inner fastening points 54A, 55A being axially arranged on the same side of the median plane of the tire, and the second radially outer fastening points 56B, 57B and the second radially inner fastening points 54B, 55B being axially arranged on the same other side of the median plane of the tire.

[0156] Each of the first and second radially outer fastening points 57A, 57B for each axially inner fastening stiffening element 53 is axially inward of each of the first and second radially outer fastening points 56A, 56B for each axially outer fastening stiffening element 52.

[0157] It should be noted that each of the first radially inner fixation points 55A and each of the first radially inner fixation points 54A are aligned radially and axially on the same circumferential line, and likewise, each of the second radially inner fixation points and each of the second radially inner fixation points 54B are aligned radially and axially on the same circumferential line.

[0158] It should also be noted that the first and second radially inner and outer fastening points 55A, 55B, 57A, 57B are in the same meridian section as the first and second radially inner fastening points and the first and second radially outer fastening points 54A, 54B, 56A, 56B, respectively. In a variant not shown, it is likewise conceivable that the first and second radially inner and outer fastening points 55A, 55B, 57A, 57B are in a different meridian section than the first and second radially inner and the first and second radially outer fastening points 54A, 54B, 56A, 56B, respectively.

[0159] In this fourth embodiment, each of the first and second radially inner anchoring reinforcing structures 60A, 60B for each axially inner anchoring stiffening element 53 is respectively the first and second radially inner anchoring reinforcing structures 60A, 60B for each axially outer anchoring stiffening element 52. Furthermore, the first and second radially outer anchoring reinforcing structures 70A, 70B for each axially inner anchoring stiffening element 53 is respectively the radially outer anchoring stiffening structure 70A, 70B for each axially outer anchoring stiffening element 52. In a variant, it can be assumed that they are separate.

[0160] Figure 9 shows a tire according to a fifth embodiment of the invention. Elements similar to those of tires according to conventional embodiments are designated with the same reference numbers.

[0161] Unlike the fourth embodiment, the stiffening structure 50 comprises radially and axially outer anchoring stiffening elements 52 and radially and axially inner anchoring stiffening elements 53. The stiffening structure 50 comprises a first radially outer anchoring reinforcing structure 60A of each radially and axially outer anchoring stiffening element 52 in the first side wall 30A and a first radially inner anchoring reinforcing structure 61A of each radially and axially inner anchoring element 53 in the first side wall 30A, which reinforcing structure 61A is distinct from the first radially outer reinforcing structure 60A and the first circumferential reinforcing element 40A. The stiffening structure 50 also comprises a second radially outer fixing reinforcing structure 60B of each radially and axially outer fixing stiffening element 52 in the second side wall 30B and a second radially inner fixing reinforcing structure 61B of each radially and axially inner fixing stiffening element 53 in the second side wall 30B, which reinforcing structure 61B is distinct from the second radially outer reinforcing structure 60B and the second circumferential reinforcing element 40B.

[0162] Unlike the fourth embodiment, each of the first and second radially inner fixing points 55A, 55B for each radially and axially inner fixing stiffening element 53 is radially inward of each of the first and second radially inner fixing points 54A, 54B for each radially and axially outer fixing stiffening element 52.

[0163] It should be noted that the first and second radially outer fixation points 57A, 57B, respectively, and the first and second radially outer fixation points 56A, 56B, respectively, are axially offset relative to one another, although in a variant it can be assumed that they are aligned radially and axially on the same circumferential line.

[0164] It should be noted that each of the first and second radially inner reinforcing structures 60A, 60B is distinct from each of the first and second radially inner reinforcing structures 61A, 61B. In this case, each radially inner reinforcing structure 60A, 60B, 61A, 61B comprises respective thread line reinforcement elements 62A, 62B, 63A, 63B that are separate and discontinuous from the thread line reinforcement elements of the other radially inner reinforcing structure within the same sidewall and / or the same bead. In a variant, it can be assumed that these radially inner reinforcing structures are the same.

[0165] 10 to 13 show a tire according to a sixth embodiment of the present invention, in which elements similar to those of the tire according to the conventional embodiment are designated by the same reference numerals.

[0166] Unlike the previous embodiment, each of the first and second radially inner reinforcing structures 60A, 60B comprises a respective portion 34A1, 34B1 of the carcass reinforcement 34 extending radially through each of the side walls 30A, 30B. In this case, each stiffening element 52A, 52B is at least partially wrapped around a carcass thread line reinforcement element 340 of a respective portion 34A1, 34B1 of the carcass reinforcement 34 extending radially through each of the side walls 30A, 30B.

[0167] In a similar manner, each of the first and second radially outer reinforcing structures 70A, 70B comprises a respective portion 34A2, 34B2 of the carcass reinforcement 34 extending axially in the crown. In this case, each stiffening element 52A, 52B is at least partially wrapped around a carcass thread line reinforcement element 340 of the respective portion 34A2, 34B2 of the carcass reinforcement 34 extending axially in the crown.

[0168] Unlike the previous embodiments, in this sixth embodiment, each of the first and second stiffening elements 52A, 52B is fixed in, and not around, each of the first and second radially inner reinforcing structures 60A, 60B and each of the first and second radially outer reinforcing structures 70A, 70B formed by the respective corresponding portions 34A1, 34B1, 34A2, 34B2 of the carcass reinforcement 34.

[0169] Figure 14 shows a tire according to a seventh embodiment of the invention. Elements similar to those of the tire according to the conventional embodiment are designated with the same reference numerals.

[0170] Different from the first embodiment, the first and second beads 32A, 32B comprise respective circumferential reinforcing elements 40A1, 40A2 and 40B1, 40B2 enabling the anchoring of the carcass reinforcement 34. Each of these circumferential reinforcing elements is a continuous threadline reinforcing element comprising a number of circumferential turns about a pivot axis radially overlapping one another.

[0171] Of course, embodiments can be envisaged which comprise circumferential reinforcing elements identical to the seventh embodiment combined with the stiffening structures of the second, third, fourth, fifth and sixth embodiments.

[0172] Comparative Test

[0173] To clarify the advantages of the invention in terms of the durability of the stiffening structure, a comparison is made between a tire 10 according to the first embodiment and a prior art tire R described in WO2020 / 128225 but with dimensions 275 / 35R19. Each of the tires 10 and R is mounted on a nominal rim and inflated to a pressure equal to 250 kPa. A test is then carried out similar to the load / speed performance test described in Appendix VII of EEC-UNO Regulation No. 30, but under more severe load and speed conditions. The number of kilometers traveled until the first detachment of a stiffening element is observed is then recorded. This number of kilometers traveled is referred to a reference value of 100 corresponding to the number of kilometers traveled of the prior art tire R, so that a number of kilometers traveled exceeding 100 represents an improvement in terms of the durability of the stiffening structure.

[0174] The test is passed if the tire is suitable for use after a kilometer threshold that each manufacturer sets as a function of its specifications, for example between 10,000 km and 50,000 km. Prior art tire R was tested under the above conditions, and after a number of kilometers less than the determined kilometer threshold, prior art tire R was no longer suitable for use due to a pressure loss associated with its structural deterioration. In contrast, tire 10 according to the first embodiment exceeded the kilometer threshold without deterioration and was able to withstand many more kilometers.

[0175] The radial stiffness Kzz, the axial stiffness Kyy, and the cornering stiffness D(z) were also compared for the tire 10 according to the first embodiment and the tire R. These stiffnesses are substantially the same as the stiffness of the tire with the dimensions 275 / 35R19 described in WO2020 / 128225, and are much better than the stiffness of conventional prior art tires without stiffening structures.

[0176] In order to clarify the additional and optional advantages of the embodiment with good tread flattening, a comparison was made between the tire 10 according to the first embodiment and a control tire R' also according to the invention, in which the first radially outer fixation point is located axially opposite the first radially inner structure with respect to the median plane of the tire, and the second radially outer fixation point is located axially opposite the second radially inner structure with respect to the median plane of the tire, so that the portions 523 and 524 cross over in the toroidal cavity 35. The contact area of ​​each tire 10 and R' with the ground under a load above the nominal load was simulated, with each tire 10 and R' subjected to a given lateral force F, mounted on a nominal rim and inflated to a pressure equal to 250 kPa, so as to simulate a load transfer equivalent to that observed on the outer wheel of a vehicle dealing with a turn. It should be noted in figures 15 and 16 that the tire 10 has a smaller number of axial bending zones than the control tire R'. In figures 17 and 18, the axial limits of each rib of the tread of tire 10 are represented by dashed lines so that the contact areas can be compared with each other. It can be seen that each rib of the tread of tire 10 has a contact area width significantly greater than the contact area width of the corresponding rib of tire R'. As mentioned above, the fact that portions 523 and 524 cross over in the toroidal cavity of tire R' results in the appearance of multiple axial bending zones of the tread and therefore a reduction in the axial width of the rib in contact with the ground due in particular to the radial displacement of the axial edges of each rib in the spaces formed by the longitudinal grooves of the tread which they define.

[0177] A description will now be given of the tools and methods that allow the manufacture of tires according to the invention.

[0178] To manufacture the tire 10 according to the first embodiment, the tools and methods described below are used.

[0179] As shown in Figures 19A, 19B and Figures 20A, 20B, the tool comprises a torus-shaped core 1000 having a convex outer receiving surface 1000_out about its main axis Z10, a radially outer crown zone 1100 intended to receive a part having a crown 12, a first lateral zone 1200 curved towards the main axis Z10 of the torus-shaped core and intended to receive components of the first side wall 30A and the first bead 32A, and a second lateral zone 1300 curved towards the main axis Z10 of the torus-shaped core and intended to receive components of the second side wall 30B and the second bead 32B.

[0180] As a result, the core 1000 is delimited from the outside by a receiving surface 1000_out and defines a so-called reserved volume which corresponds to the internal cavity 35. The core 1000 can thus occupy and thus reserve a volume whose shape and dimensions correspond to the internal cavity 35 temporarily during the manufacture of the tire, this volume becoming the internal cavity 35.

[0181] The core 1000 has a number of passages 1500 extending inside the retention volume below the receiving surface 1000_out and opening above the receiving surface 1000_out, each of the passages 1500 connecting the crown zone 1100 of the receiving surface 1000_out to one of the first and second lateral zones 1200, 1300 such that the core 10 can receive the stiffening element 52 in the passage 1500. The grooves 1500 are blind grooves and have a solid bottom 1900 located below the receiving surface 1000_out in the retention volume.

[0182] As can be seen in particular in FIG. 20A , the core 1000 comprises an assembly made up of a number of annular subassemblies 2100, 2200, 2300 comprising: i) a first annular subassembly 2100, called central crown 2100, forming a central part of the crown zone 1100 of the receiving surface 1000_out intended to receive one or more components of the crown 12; ii) a second annular subassembly 2200, called left ear 2200, enclosing a groove 1500 forming a passageway towards the stiffening element 52 connecting the first side wall 30A to the crown 12; and iii) a third annular subassembly 2300, called right ear 2300, enclosing a groove 1500 forming a passageway towards the stiffening element 52 connecting the second side wall 30B to the crown 12.

[0183] Each of the annular subassemblies 2100, 2200, 2300 is divided angularly in azimuth about the main axis Z10 into sectors 2400, 2500, 2600, 2800, 2900, 2500, 2500, 2600, 2700, 2800, 2900 alternating with so-called "key" sectors 2400, 2600, 2800, 2900 and so-called "vault" sectors 2500, 2700, 2900 designed to be held in place and locked by the keys 2400, 2600, 2800 and to facilitate manipulation after release by removing the keys 2400, 2600, 2800. The central ring 2100 is divided into a number of ring keys 2400 and ring vaults 2500. Both the lug keys 2600, 2800 and the lug vaults 2700, 2900 are preferably made from a metal alloy, more preferably an aluminum alloy.

[0184] The method for manufacturing the tire 10 is in fact equivalent to using a tool as described above. The method comprises a preparation step (S0) of preparing the tool. During the preparation step (S0), as shown in Figures 20A and 20B, the key 2400 and the vault 2500 are assembled to form a central ring, after which successive ear keys 2600, 2800 and ear vaults 2700, 2900 are fixed on the respective clearance surfaces 3200, 3300 to form the ears 2200, 2300.

[0185] The method then comprises a step (S2) of fitting the stiffening elements 52, during which the stiffening elements 52 are passed through each passage 1500. For this purpose, the stiffening elements 52 are arranged successively along a boustrophedonic path through successive passages 1500, here by inserting a successive stiffening element 52 into the grooves 1500 so that, as can be seen in Fig. 21, the successive stiffening elements 52 emerge above the receiving surface 1000_out at the level of the radially inner fastening points 54A, 54B and the radially outer fastening points 56A, 56B in the crown zone 1100 and in the lateral zones 1200, 1300. In that case, at a stage not shown, the method comprises a protection stage (S3) using an anti-penetration device (not shown) which cooperates with the core 1000 during the mounting stage (S4) and the curing stage (S5) to constitute an obstacle to the penetration of components of the crown 12, the side walls 30A, 30B and the beads 32A, 32B into the groove 1500 in which the stiffening element 52 is engaged. It is envisaged that such an anti-penetration device could comprise an element for filling the groove 1500 or a masking band or shell placed across the groove to cover it.

[0186] The method then comprises a mounting step (S4) in which the components of the crown 12, the sidewalls 30A, 30B and the beads 32A, 32B are placed on the receiving surface 1000_out. These components comprise bands or layers based on polymer compounds and thread reinforcement elements making it possible to form the various layers of the tire 10.

[0187] The method then comprises a curing step (S5) during which the core 1000 and the preform of tire 10 supported on the core 1000 are placed in a curing mould to vulcanise the components.

[0188] The method then comprises a step (S6) of extraction from the mould, during which the core 1000 of the tyre 10 is disengaged leaving the stiffening element 52 in place in the internal cavity 35, as shown in particular in the extraction sequence of Figures 22A-22F. This part is removed and gradually extracted to free the tyre 10. The extraction step (S6) from the mold first comprises a first substep of removing the central ring 2100, during which the vault 2500 of the central ring is removed after the key 2400 has been radially removed from the central ring in order to release the ears 2200, 2300, the configuration of which is such that the sectors 2600, 2700, 2800, 2900 of the ears 2200, 2300 are accessible from the inside of the tire 10 as shown in FIG. 22A, then a second substep of extracting the first ear 2200, during which the key 2600 of one of the left or right ears is removed from the internal cavity 35 in order to release the corresponding part of the internal cavity 35 and the stiffening element 52 located therein, and then a third substep of extracting the other ear 2300, carried out similarly to the second substep. Here, the sectors 2600, 2700, 2800, 2900 are achieved by an axial extraction movement in translation M_A, as shown in FIG. 22B, when the side walls of the groove 1500 are generated in an axial generatrix direction DG_A collinear with the main axis Z10, and the axial extraction movement in translation M_A can be followed by a tilting movement with pitch M_B around an axis perpendicular to the sagittal meridian plane of said sectors 2600, 2700, 2800, 2900, as shown in FIG. 22D, 22E. When the sectors 2600, 2700, 2800, 2900 have left the stiffening element 52, they can be free to complete the extraction sequence from the inside of the tire 10, for example by a radial movement that moves said sectors 2600, 2700, 2800, 2900 towards the main axis Z10 so as to completely remove said sectors from the tire 10, as shown in FIG. 22F. The anti-penetration devices can be removed either when the sectors 2600, 2700 of ear 2200 are removed or after each of the ears 2200, 2300 has been released in sequence.For example, in the case of masking bands, they can be removed by spiral sliding, which slides the masking band into the space contained between two successive stiffening elements 52 .

[0189] After the preparation step (S0) and before step (S2), the method comprises a pre-fitting step (S1), during which the radially inner reinforcing structures 60A, 60B and the radially outer reinforcing structures 70A, 70B are placed in the lateral zones 1200, 1300 and the crown zone 1100 of the receiving surface 1000_out of the core 1000, facing the radially inner fastening points 54A, 54B and the radially outer fastening points 56A, 56B, as shown in Figure 21. The loops forming the portions 521, 522 will be found to be captured on the radially inner reinforcing structures 60A, 60B and other adjacent components of the tire 10 placed in the lateral zones 1200, 1300, while the portion 525 will be found to be captured on the radially outer reinforcing structures 70A, 70B and other adjacent components of the tire 10.

[0190] The present invention is not limited to the above-described embodiments.

[0191] Indeed, it would of course be conceivable to combine the second embodiment with the fourth and fifth embodiments.

[0192] Without departing from the scope of the invention, for example, it is possible to envisage the use of cavity noise absorbers fixed to the mounting body of the tire or to the tire itself in order to reduce the tire's cavity noise. Noise absorbers of this kind are described, inter alia, in WO2018046376, WO2013182477, WO201051203, EP2660075, EP1253025, EP1876038 and EP3406462. [Explanation of symbols]

[0193] 10 Tires 12 crowns 35 Torus-shaped cavity 50 Stiffening structure 52 Reinforcing elements M Median surface of tire

Claims

1. The tire comprises a crown (12) extending radially inwards by two side walls (30A, 30B) and then by two beads (32A, 32B), each bead (32A, 32B) comprising at least one circumferential reinforcing element (40A, 40B) intended to enable the tire (10) to be mounted on a mounting support for the tire (10), The tire (10), an inner surface (33) defining a torus-shaped expansion cavity (35) for the tire; a stiffening structure (50) comprising at least one stiffening element (52; 52A, 52B; 53) extending continuously within said toroidal cavity (35) from at least one of said side walls (30A, 30B) of said beads (32A, 32B) at least as far as said crown (12); A tire (10) having The or each stiffening element (52; 52A, 52B; 53) is at least one radially inner reinforcing structure (60A, 60B; 61A, 61B) arranged on said sidewall (30A, 30B) and / or on said bead (32A, 32B), said at least one radially inner reinforcing structure (60A, 60B; 61A, 61B) being distinct from the or each circumferential reinforcing element (40A, 40B) located on the same side of the median plane (M) of the tire (10) as said sidewall (30A, 30B) and / or said bead (32A, 32B); At least one radially outer reinforcing structure (70A, 70B; 73) disposed in said crown (12); Attached to or around A tire (10).

2. The or each stiffening element (52; 53) is a first radially inner reinforcing structure (60A; 60B) arranged on the first sidewall (30A) and / or on the first bead (32A), said first radially inner reinforcing structure (60A; 60B) being distinct from said first sidewall (30A) and / or said first bead (32B) and from the or each circumferential reinforcing element (40A) located on the same first side of said median plane (M) of the tire (10); said radially outer reinforcing structure (70A, 70B; 73) or a plurality of said radially outer reinforcing structures (70A, 70B; 73) in said crown (12); a second radially inner reinforcing structure (60B; 61B) arranged on a second sidewall (30B) and / or a second bead (32B) located on the other side of the first sidewall (30A) and / or the first bead (32A) with respect to the median plane (M) of the tire (10), said second radially inner reinforcing structure (60B; 61B) being distinct from the second sidewall (30B) and / or the second bead (32B) and from the or each circumferential reinforcing element (40B) located on the same second side of the median plane (M) of the tire (10); affixed to or around the whereby said or each stiffening element (52; 53) extends continuously within said crown (12) from said first side wall (30A) and / or said first bead (32A) to said second side wall (30B) and / or said second bead (32B), 2. The tire (10) of claim 1.

3. The or each stiffening element (52; 53) is said first radially inner reinforcing structure (60A; 61A); first and second radially outer reinforcing structures (70A, 70B; 73) within said crown (12); said second radially inner reinforcing structure (60B; 61B); affixed to or around Tyre (10) according to claim 2 .

4. The or each stiffening element (52; 52A, 52B; 53) is a first radially inner fastening point (54A; 55A) passing through said inner surface (33) such that the or each stiffening element (52; 52A, 52B; 53) is fastened to or around said first radially inner reinforcing structure (60A; 61A); a first radially outer fastening point (56A; 57A) passing through said inner surface (33) such that the or each stiffening element (52; 52A, 52B; 53) is fastened to or around said radially outer reinforcing structure (70A, 70B; 73) or a plurality of said radially outer reinforcing structures (70A, 70B; 73); a portion (523) extending within said toroidal cavity (35) between The or each stiffening element (52; 52A, 52B; 53) is second radially inner fastening points (54B; 55B) passing through said inner surface (33) such that the or each stiffening element (52; 52A, 52B; 53) is fastened to or around said second radially inner reinforcing structure (60B; 61B); a second radially outer fastening point (56B; 57B) passing through said inner surface (33) such that the or each stiffening element (52; 52A, 52B; 53) is fastened to or around said radially outer reinforcing structure (70A, 70B; 73) or a plurality of said radially outer reinforcing structures (70A, 70B; 73); a portion (524) extending within said toroidal cavity (35) between Each or said first and second radially inner fastening points (54A, 54B; 55A, 55B) and radially outer fastening points (56A, 56B; 57A, 57B) are the first radially outer fastening point and the radially inner fastening point (54A, 56A; 55A, 57A) are on the same side in the axial direction of the median plane (M) of the tire (10); the second radially outer and inner fastening points (54B, 56B; 55B, 57B) are on the same other side in the axial direction of the median plane (M) of the tire (10); and the portion (523) extending between the first radially outer and inner fixing points (54A, 56A; 55A, 57A) and the portion (524) extending between the second radially outer and inner fixing points (54B, 56B; 55B, 57B) do not cross over within the toroidal cavity (35); It is like, Tyre (10) according to claim 2 or 3.

5. 5. Tyre (10) according to any one of claims 2 to 4, characterized in that the stiffening structure (50) comprises a plurality of stiffening elements (52; 53) forming a continuous stiffening element so as to describe a boustrophedonic trajectory through the crown (12) between the first sidewall (30A) and / or the first bead (32A) and the second sidewall (30B) and / or the second bead (32B).

6. Tyre (10) according to any one of the preceding claims, characterized in that the or each stiffening element (52; 52A, 52B; 53) is a fibre reinforcing element.

7. 7. Tyre (10) according to any one of claims 1 to 6, characterized in that the or each radially inner reinforcing structure (60A, 60B; 61A, 61B) and / or the or each radially outer reinforcing structure (70A, 70B; 73) comprises at least one fibrous reinforcing element (62A, 62B, 72A, 72B; 63A, 63B) extending along a main direction which forms an angle less than or equal to 10° with the circumferential direction (X) of the tyre (10).

8. The tire (10) has a substantially toroidal shape about a pivot axis, the fibrous reinforcing elements (62A, 62B; 63A, 63B) of the radially inner reinforcing structure (60A, 60B; 61A, 61B) are wound around the pivot axis over a maximum of two complete turns, Tyre (10) according to claim 7.

9. The tire (10) has a substantially toroidal shape about a pivot axis, the fibrous reinforcing elements (72A, 72B) of the or each radially outer reinforcing structure (70A, 70B; 73) are wound circumferentially over at least two complete turns around the pivot axis and at most ten complete turns around the pivot axis, Tyre (10) according to claim 7 or claim 8.

10. Tyre (10) according to any one of claims 7 to 9, characterized in that the or each stiffening element (52; 52A, 52B; 53) is at least partially wrapped around the or each fibrous reinforcing element (62A, 62B, 72A, 72B; 63A, 63B).

Images