FR3112311A1 - Passenger car tire - Google Patents

Abstract

The tire (10) comprises a load-bearing structure comprising load-bearing elements and a floating sole arranged radially inside the crown and connected to the crown via the load-bearing elements. The tire (10) is arranged to move radially inward a portion (52D, 54D) of the floating sole located radially in line with the running surface (38). The load-bearing structure (50) comprises a connecting element (68, 70) between the floating sole (52, 54) and one of the sidewalls (30) arranged so that, under the effect of the displacement (Di) radially towards the inside the portion (52D, 54D) of the floating sole located radially in line with the running surface (38), the connecting element (68, 70) is able to exert on a radial portion (30D) of the sidewall located radially in line with the running surface (38) a tensile force (Tr) directed at least radially inwards. Figure for abstract: Fig 4

Description

Passenger car tire

The present invention relates to a tire for a passenger vehicle. By tire is meant a tire intended to form a cavity by cooperating with a support element, for example a rim, this cavity being capable of being pressurized to a pressure greater than atmospheric pressure. A tire according to the invention has a structure of substantially toroidal shape of revolution around a main axis of the tire.

We know from the state of the art a tire intended to equip a passenger vehicle and described in WO2019/092343. The tire described comprises a crown extended radially inwards by a sidewall then by a bead intended to come into contact with a mounting support, for example a rim. The crown comprises a tread intended to come into contact with a rolling ground. The tire also comprises a carcass reinforcement anchored in each bead and extending in each sidewall and radially internally at the crown.

The assembly made up of the crown, the two sidewalls and the two beads is intended to delimit an internal toric cavity once the tire is mounted on the mounting support, this cavity being able to be pressurized by an inflation gas.

The tire described in WO2019/092343 comprises a supporting structure comprising first and second flanges fixed relative to the crown arranged radially inside the crown and first and second floating flanges arranged radially inside the first and second fixed flanges. The supporting structure also comprises supporting elements connecting together each first and second fixed footing and respectively each first and second floating footing. In one of the embodiments described in WO2019/092343, the tire also comprises a connecting element between each first and second floating sole and each bead of the tire

The tire is arranged so that, when the tire is inflated to a nominal pressure and is subjected to a nominal load and is in contact with a rolling ground via a rolling surface, a part of the load-bearing elements located radially opposite the rolling surface in contact with the ground are in tension so as to move radially outwards a portion of the floating sole located radially opposite the rolling surface in contact with the floor. The floating sole having a non-zero circumferential extension stiffness, the radially outward displacement of the portion of the floating sole located radially opposite the tread surface in contact with the ground also causes a radially outward displacement. inside a portion of the floating sole located radially in line with the running surface in contact with the ground.

Despite significantly improved lateral stiffness performance compared to a similar tire without a supporting structure, the tire described in WO2019/092343 has, under strong lateral stresses, the disadvantage of generating relatively high pressures at the axial ends of the tread. also called tire shoulders. However, it is known that the increase in the pressure exerted by the road surface on the tread leads to a loss of grip, at least on dry ground, which is detrimental to the behavior of the tire.

The object of the invention is a tire comprising a supporting structure and having improved grip on dry ground under strong lateral stresses.

Thus, the subject of the invention is a tire intended to be inflated to a nominal pressure and to be subjected to a nominal load, comprising:
- a crown extended radially inwards, by two sides then by two beads, each bead being intended to come into contact with an assembly support,
- a supporting structure comprising supporting elements and a floating sole arranged radially inside the crown, the floating sole being connected to the crown via the supporting elements,
the tire being arranged so that, when the tire is inflated to a nominal pressure and is subjected to a nominal load and is in contact with a rolling ground via a rolling surface, at least part of the supporting elements located radially opposite the running surface in contact with the ground is in tension so as to displace radially inwards a portion of the floating sole located radially in line with the running surface in contact with the ground ,
the support structure comprising at least one connecting element between the floating sole and at least one of the sidewalls arranged so that, under the effect of the radially inward displacement of the portion of the floating sole located radially in line with the rolling surface in contact with the ground, the connecting element is able to exert on at least one radial portion of the sidewall located radially in line with the rolling surface in contact with the ground a tensile force directed at least radially inwards.

Unlike the tire of WO2019/092343 comprising a supporting structure, the tire according to the invention makes it possible to reduce the pressure on the shoulder of the tire. In fact, in the tire of WO2019/092343, the tensioning of the part of the load-bearing elements located radially opposite the running surface in contact with the ground indeed causes a radially inward displacement of the portion of the floating sole located radially in line with the running surface in contact with the ground but without being able to exert a tensile force directed radially inwards on any portion of the sidewall because the connecting element is connected to the bead of the tire, which being in contact with the mounting bracket, is substantially non-deformable. On the contrary, in the tire according to the invention, the tensioning of the part of the carrier elements located radially opposite the running surface in contact with the ground causes a radially inward displacement of the portion of the floating sole located radially in line with the running surface in contact with the ground and also the application of a tensile force directed at least radially towards the inside of the tire due to the connection of the connecting element to the sidewall. The tensile force directed at least radially inwards causes a radially inward displacement of the radial portion of the sidewall located radially outside the connection zone between the connecting element and the sidewall. The radial portion of the sidewall subjected to the tensile force is located radially between the connection zone and the crown of the tire, more precisely between the most radially outer point of the connection zone and the crown of the tire. This radial displacement of the radial portion subjected to the traction force makes it possible to reduce the pressure exerted by the road surface on the shoulder of the tire under strong lateral stresses, which improves the grip of the tire due to the drop in local pressure exerted by the road surface on the tire.

A portion of an element or an element located in line with the running surface in contact with the ground is the portion of this element or the element radially closest to the portion of the ground in contact with the tire. In contrast, a portion of an element or an element located radially opposite the running surface in contact with the ground is the portion of this element or an element radially farthest from the portion of the ground in contact with the ground. pneumatic.

The tensile force is applied to the connection area of the connecting element with the sidewall. By being directed at least radially inward, the tensile force has at least one radially inward component.

In addition, the connecting element makes it possible to guarantee flexibility between the floating sole and the rest of the tire, in the invention the sidewall, thus allowing damping of the mechanical vibrations transmitted by the supporting elements, during rolling of the tire, between the ground and the vehicle and likely to generate noise inside the vehicle that is annoying for the driver of the vehicle.

One of the aspects of the tire according to the invention is to install, in a conventional tire, a load-bearing structure participating at least partially in carrying the load applied to the tire, such that this applied load is taken up jointly by the tire, thanks to its pneumatic rigidity and its structural rigidity, and by the load-bearing structure, thanks to the rigidity of its constituent load-bearing elements. By at least partial participation of the bearing structure in the bearing of the applied load, is meant a participation in the bearing of the load, by way of indication, at least equal to 5% and at most equal to 70% of the applied load. The distribution of the bearing of the load applied between the tire and the load-bearing structure depends on their respective rigidities.

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

In addition, the load-bearing structure limits the deformation of the crown, during rolling, as well as the counter-deflection, that is to say the radial deformation, opposite to the running surface in contact with the ground. Thus, during rolling of the tire, around the wheel, the support structure makes it possible to limit the amplitude of the cyclic deformations of the tire, and in particular of its tread, and therefore to limit the resulting dissipation of energy, this which helps to reduce rolling resistance.

Concerning the mechanical behavior of the tire under axial stresses, for example during drifting, the load-bearing structure will contribute to increasing the axial rigidity of the tire, and therefore to improving this behavior. This contribution to the axial rigidity of the tire is advantageously obtained by the inclination of the supporting elements with respect to a radial direction of the tire.

On a structural level, according to the invention, the load-bearing structure consists of load-bearing elements, two by two independent, extending in the internal toric cavity, from the top to the floating sole. The operating principle of such a supporting structure is to carry at least part of the load applied to the tire by tensioning at least part of the supporting elements.

The load-bearing elements are two by two independent, i.e. not mechanically linked together in the inner toric cavity of the tire, so that they have independent mechanical behavior. For example, they are not linked together in such a way as to form a network or a lattice.

Each load-bearing element extends continuously in the inner toric cavity, from the crown to the floating sole, that is to say over a length and in a main direction making it possible to directly connect the crown and the floating sole to each other. .

The assembly made up of the crown, the two sidewalls and the two beads is intended to delimit an internal toric cavity once the tire is mounted on the mounting support, usually a rim. The load-bearing elements extend into the inner toroidal cavity.

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

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

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

By radial direction is meant the direction along a radius of the tire, that is to say any direction intersecting the axis of rotation of the tire and substantially perpendicular to this axis.

The median plane of the tire (denoted M) means the plane perpendicular to the axis of rotation of the tire which is located at the axial mid-distance of the two beads and passes through the axial center of the crown reinforcement.

By equatorial circumferential plane of the tire (denoted E), is meant, in a meridian section plane, the plane passing through the equator of the tire, perpendicular to the median plane and to the radial direction. The equator of the tire is, in a meridian section plane (plane perpendicular to the circumferential direction and parallel to the radial and axial directions) the axis parallel to the axis of rotation of the tire and located equidistant between the radially most outside of the tread intended to be in contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example a rim, the distance between these two points being equal to H.

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

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

By bead is meant the radial portion of the tire intended to allow the attachment of the tire to a mounting support, for example a wheel comprising a rim. Thus, each bead is in particular intended to be in contact with a hook of the rim allowing it to be attached. The bead is thus delimited radially internally by the radially inner end of the tire and radially externally by an axial straight line passing through the radially outermost point in contact with a standard rim within the meaning of the standard of the European Tire and Rim Technical Organization or “ETRTO”, 2019.

By sidewall is meant the radial portion of the tire connecting the bead to the crown. The sidewall is delimited radially externally by a straight line perpendicular to the external surface of the tire passing through the point for which the angle between the tangent to the external surface of the tire and a straight line parallel to the axial direction passing through this point is equal to 30 °. When there are several points on a meridian section plane for which said angle is equal in absolute value to 30°, the radially outermost point is retained. The sidewall is delimited radially internally by an axial straight line passing through the radially outermost point with a standard rim within the meaning of the standard of the European Tire and Rim Technical Organization or “ETRTO”, 2019.

Any interval of values designated by the expression "between a and b" represents the range of values going from more than a to less than b (i.e. limits a and b excluded) while any interval of values designated by the expression “from a to b” means the range of values going from a to b (that is to say including the strict limits a and b).

The tires of the invention are intended for passenger vehicles as defined within the meaning of the standard of the European Tire and Rim Technical Organization or "ETRTO", 2019. Such a tire has a section in a meridian section plane characterized by a section height H and a nominal section width or flange size S within the meaning of the standard of the European Tire and Rim Technical Organization or “ETRTO”, 2019.

The tires of the invention are preferably intended for passenger vehicles. Such a tire has a section in a meridian section plane characterized by a nominal section width or section thickness S and a section height H, within the meaning of the standard of the European Tire and Rim Technical Organization (designated by the acronym " ETRTO") - Standards Manual 2019, such that the H/S ratio, expressed as a percentage, is at most equal to 90, preferably at most equal to 80 and more preferably at most equal to 70 and is at least equal to 30, preferably at least equal to 40, and the nominal section width S is at least equal to 115 mm, preferably at least equal to 155 mm and 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 and even more preferably at most equal to 255 mm. In addition, the hook diameter D, defining the diameter of the mounting rim of the tire, 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 20 inches.

Conventionally, in a tire comprising a crown reinforcement and a carcass reinforcement, the crown comprises a tread intended to come into contact with the road surface and a crown reinforcement arranged radially inside the tread . The tire also comprises a carcass reinforcement anchored in each bead and extending in each sidewall and radially internally at the crown. Conventionally, the crown reinforcement comprises at least one crown layer comprising reinforcing elements. These reinforcing elements are preferably textile or metallic wire elements.

In embodiments making it possible to obtain the performance of so-called radial tires as defined by the ETRTO, the carcass reinforcement comprises at least one carcass layer, the or each carcass layer comprising corded carcass reinforcement elements, each carcass wire reinforcement element extending substantially along a main direction forming with the circumferential direction of the tire, an angle, in absolute value, ranging from 80° to 90°.

Advantageously, the or each connecting element is arranged so that, under the effect of the radially inward displacement of the portion of the floating sole located radially in line with the running surface in contact with the ground, the or each connecting element is capable of exerting on the radial portion of the or each sidewall located radially in line with the running surface in contact with the ground a tensile force directed axially and radially inwards.

The orientation of the force axially inwards makes it possible to contribute more to the reduction of the pressure at the shoulder of the tire and therefore to the improvement of the grip of the tire. This improvement is particularly notable under strong lateral stresses which generate a significant axial offset of the crown relative to its mounting support and for which the connecting element and the load-bearing elements take up part of the axial forces exerted on the crown by exerting on the flank the tensile force directed axially inwards.

The tensile force is applied to the connection area of the connecting element with the sidewall. By being directed axially and radially inward, the tensile force has two components respectively axially and radially inward.

Preferably, the or each connecting element is arranged so that, when the tire is inflated to the nominal pressure and is subjected to the nominal load and is in contact with a road surface via the surface of bearing, under the effect of the radially inward displacement of the portion of the or each floating sole located radially in line with the tread surface in contact with the ground, at least a portion of the or each bead located radially in right of the running surface in contact with the ground is placed in compression between the or each connecting element and the mounting support.

This also improves the anchoring of the bead against the mounting support and reduces the risk of the bead coming out of the mounting support.

In a particularly advantageous embodiment, the tire is arranged so that, when the tire is inflated to the nominal pressure and is subjected to the nominal load and is in contact with the rolling ground via the running surface, at least a part of the support elements located radially opposite the rolling surface in contact with the ground is in tension so as to move radially outwards a portion of the or each floating sole located radially opposite the running surface in contact with the ground. The sole having a non-zero circumferential extension stiffness, it is the radially outward displacement of the portion of the floating sole located radially opposite the running surface in contact with the ground which, in this mode embodiment, to induce the radially inward displacement of the portion of the floating sole located radially in line with the rolling surface in contact with the ground in accordance with the invention.

In a preferred embodiment, the tire is arranged so that, when the tire is inflated to the nominal pressure and is subjected to the nominal load and is in contact with the rolling ground via the running surface, at the least part of the load-bearing elements located radially in line with the rolling surface in contact with the ground is subjected to buckling in compression.

Thus, correct flattening of the tire when it comes into contact with the ground is guaranteed. Indeed, it is avoided that, by tensioning the supporting elements located radially in line with the running surface in contact with the ground, the running surface is not reduced or deformed, which would in particular lead to a drop in certain performance of the tires, such as grip or rolling resistance.

The characteristics which will be described later in the generic description relate to the tire in the absence of a load applied to the tire. In other words, the following characteristics are present on a tire, inflated or not, on which no load is applied.

In one embodiment allowing easy manufacture of the tire according to the invention and obtaining high endurance of the connection zone between the connecting element and the portion of the floating sole located radially opposite the surface of bearing in contact with the ground, in any meridian section plane of the tire, the radially innermost connection point of the connection zone between the or each connecting element and the or each sidewall is located radially outside the point axially outermost connection zone of the connection zone between the or each connecting element and the or each floating pad.

In this embodiment, the relative radial positions of the connection points make it possible to ensure that, thanks to a particular radial positioning of the connection points with respect to each other, under the effect of the displacement radially towards the inside the portion of the floating sole located radially in line with the running surface in contact with the ground, the connecting element is able to exert the tensile force directed at least radially inwards on the radial portion of the sidewall located radially in line with the running surface in contact with the ground.

Furthermore, due to the relative radial positions of the connection points, during the radially outward movement of the portion of the floating sole located radially opposite the running surface in contact with the ground, the connection zone between the connecting element and the portion of the floating sole located radially opposite the tread surface in contact with the ground is slightly stressed in the radial direction and essentially only has to support the weight of the element link. On the contrary, in WO2019/092343, the connection zone between the connecting element and the portion of the floating sole located radially opposite the contact area is strongly stressed in the radial direction and must support the entire of the tension exerted by the load-bearing elements located radially opposite the running surface in contact with the ground on the floating sole, and this due to the relative radial positions of the connection points.

Preferably, each bead comprising a circumferential reinforcement element, the radially innermost connection point of the connection zone between the or each connecting element and the or each sidewall is arranged radially at a radial distance ranging from 0.1 x H at 0.5 x H from the radially outermost point of the circumferential reinforcement element or the radially outermost circumferential reinforcement element, H being the section height of the tire.

Thus, the propagation of the noise generated by the carrier structure from the carrier structure to the vehicle through the mounting support of the tire is reduced. Indeed, beyond a radial distance equal to 0.1xH, the most radially inner connection point of the connection zone between the connection element and the sidewall is far enough from the circumferential reinforcement element to that the sound waves generated by the supporting structure are damped by the structure of the tire before reaching the circumferential reinforcement element which constitutes a significant element for transmitting noise between the tire and the mounting support. Nevertheless, it is preferable that the most radially inner connection point of the connection zone between the connecting element and the sidewall is not radially too far apart so as to allow an effective take-up of axial forces between the load-bearing structure and the sidewall via the connecting element and thus participate in improving the axial rigidity.

Advantageously, in any meridian section plane of the tire, the or each connecting element extends in a general direction oriented radially and axially inwards when moving along the or each connecting element from the point of radially innermost connection of the connection zone between the or each connecting element and the or each sidewall towards the axially outermost connection point of the connecting zone between the or each connecting element and the or each floating pad.

Thus, whether for low stresses or greater stresses, the traction force is transmitted as directly as possible that the portion of the connecting element located radially in line with the tread surface in contact with the ground is capable of to be exerted on the radial portion of the sidewall. The rigidity of the connecting element is thus exclusively due to the intrinsic rigidity of the constituent material(s) of the connecting element and does not include any component linked to its geometry or its shape, as could be the case if the element link had for example a wavy shape. In other words, the general direction in which the connecting element extends does not present any change in direction of curvature. Preferably, in any meridian section plane of the tire, the general direction in which the connecting element extends describes a convex curve.

Advantageously, the supporting structure comprises first and second connecting elements between the floating sole and each side arranged so that, under the effect of the radially inward displacement of the portion of the floating sole located radially in line with the surface rolling surface in contact with the ground, each first and second connecting element is capable of exerting on at least one radial portion of each sidewall located radially in line with the rolling surface in contact with the ground a tensile force directed at least radially towards the inside. Thus, the forces can be distributed on each of the flanks. We can consider having one or two floating soles.

Preferably, the first and second connecting elements are symmetrical to each other with respect to the median plane of the tire. This variant makes it possible to distribute symmetrically and equally the radially internal attachment of the supporting structure between the two sidewalls and to distribute symmetrically and equally the forces passing through the supporting structure between the two axial sides of the tire.

Advantageously, the supporting structure comprises first and second groups of supporting elements and first and second floating soles movable independently of one another and arranged radially inside the crown, each first and second floating sole being connected to the vertex via respectively each first and second group of supporting elements. The presence of the first and second floating soleplates each connected to one of the flanks makes it possible to limit the axial width of each floating soleplate and therefore to limit the radial and axial displacements of its points. In addition, the presence of two floating soles makes it possible to distribute the radially internal attachment of the load-bearing structure between the two sidewalls and therefore to distribute the forces passing through the load-bearing structure between the two axial sides of the tire.

Preferably, the first and second connecting elements are symmetrical to each other with respect to the median plane of the tire and the first and second floating soles are symmetrical to each other with respect to the median plane of the tire. This variant of the preferred embodiment with two floating soles makes it possible to distribute the radially internal attachment of the supporting structure symmetrically between the two sidewalls and to equally distribute the forces passing through the supporting structure between the two axial sides of the tire.

Advantageously, each first and second floating sole has an axial width greater than or equal to 0.05 times the nominal section width of the tire. The axial width of the floating sole is the axial distance measured between the respectively axially inner and outer ends of the floating sole. Below this minimum value, the axial width of the floating footing is insufficient to be able to allow the attachment of the load-bearing structure to the connecting element.

Advantageously, each first and second floating sole has an axial width less than or equal to 0.4 times the nominal section width of the tire. An axial width of the floating sole, beyond this maximum value, complicates the mounting of the tire on its mounting support due to the size of the floating sole.

In other embodiments, it is possible to envisage each first and second floating sole having an axial width greater than 0.4 times the nominal section width of the tire. In these embodiments, a first and a second floating sole will be used, respectively comprising a first and a second sleeve of revolution around an axis substantially coinciding with the axis of rotation of the tire, each first and a second sleeve of revolution having then a different outer diameter so as to be able to accommodate the first and second floating soles in the tire inflation cavity without them touching.

In order to improve the endurance of the connection zone between the floating sole and the connecting element, the or each floating sole comprises a sleeve of revolution around an axis substantially coinciding with the axis of rotation of the tire and comprising :
- a radially outer surface of revolution, and
- a radially inner surface of revolution,
the connecting element being attached to the radially inner surface of revolution so as to bear radially on an axially outer end of the sleeve.

In the portion of the tire located radially in line with the running surface in contact with the ground, the radial support makes it possible to transform the radial force exerted by the floating sole on the connecting element located radially in line with the running surface in contact with the ground in an axial force shearing the connection zone between the connecting element and the floating sole. Such a shear stress is preferable because it reduces, or even eliminates, the risk of rupture of the connection zone by peeling of the connecting element with respect to the floating footing.

Advantageously, the supporting structure comprises a radially inner fabric or knit for anchoring the supporting elements, the radially inner fabric or knit being attached to the radially outer surface of revolution of the sleeve of the floating sole. Thus, there is no spatial hindrance between the load-bearing elements and the connecting element.

In order to allow easy manufacture of the tire according to the invention by relating the support structure to the raw blank of the tire during the manufacturing process, the support structure comprises a sole fixed with respect to the crown arranged radially inside the crown and radially outside the or each floating sole, the support elements interconnecting the fixed sole and the or each floating sole. The fixed sole is attached to the crown by direct application or else by gluing via an adhesive layer and is co-crosslinked with the crown during the step of crosslinking the green tire blank.

Advantageously, the supporting structure comprises first and second flanges separate from each other, fixed with respect to the crown and arranged radially inside the crown and radially outside respectively of each first and second floating flange, the load-bearing elements respectively of each first and second group of load-bearing elements interconnecting respectively each first and second fixed footing and each first and second floating footing. The separation between each first and second fixed footing, group of load-bearing elements and floating footing makes it possible to adjust the geometric position of the load-bearing structure, and more precisely the inclination of the load-bearing elements with respect to a radial direction, and consequently the tension of these carrying elements.

Preferably, the first and second fixed soles are symmetrical to each other with respect to the median plane of the tire. This design makes it possible to symmetrically distribute the radially outer attachment of the support structure, and, consequently, to distribute the forces passing through the support structure between the two axial sides of the tire.

Advantageously, each first and second fixed flange has an axial width greater than or equal to 0.05 times the nominal section width of the tire. The axial width of the fixed flange is the axial distance measured between the respectively axially inner and outer ends of the fixed flange. Below this minimum value, the axial width of the fixed flange is insufficient to be able to allow the radially external attachment of the load-bearing structure.

Advantageously, each first and second fixed sole has an axial width greater than or equal to 0.4 times the nominal section width of the tire.

Advantageously, the or each fixed sole comprises a fabric or a radially external anchoring of the load-bearing elements.

Advantageously, the or each fixed sole is of revolution around an axis substantially coinciding with the axis of rotation of the tire and comprises:
- a radially outer surface of revolution, and
- a radially inner surface of revolution,
the fixed sole being attached to a radially inner surface of the crown via the radially outer surface of revolution.

Advantageously, each carrier element comprises a wire carrier element extending in a main direction between the or one of the first and second floating soles and the crown forming, with the radial direction of the tire, an angle less than or equal to 50°. The greater the angle between the main direction in which each wire element extends and the radial direction of the tire, the greater the transverse rigidity, in the axial direction, of the tire increases, which is favorable to the behavior of the tire under heavy stresses. lateral. However, beyond 50°, due to a significant lateral force exerted on the sidewall of the tire, the bead which is connected to it risks passing over the rim and causing the tire to come off the rim.

With regard to the load-bearing structure, each load-bearing element can be characterized geometrically, in particular by its average section Sm, this characteristic not necessarily being identical for all the load-bearing elements. The average section Sm is the average of the sections obtained by cutting the carrier element through all the cylindrical surfaces, coaxial with the tire and radially included in the internal toroidal cavity. In the most frequent case of a constant section, the average section Sm is the constant section of the bearing element. The average section Sm comprises a larger characteristic dimension Dmax and a smaller characteristic dimension Dmin, the ratio of which R=Dmax/Dmin is called aspect ratio. By way of example, a carrier element having a circular average section Sm, having a diameter equal to d, has an aspect ratio R=1, a carrier element having a rectangular average section Sm, having a length L and a width l , has an aspect ratio R=L/l, and a carrier element having an elliptical middle section Sm, having a major axis D and a minor axis d, has an aspect ratio R=D/d.

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

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

According to a first structural variant of the carrier element, any carrier element has a homogeneous structure, comprising a single constituent. This is the simplest structure envisaged, such as, for example, an elementary monofilament of a single material or a layer of a single material. According to a second structural variant, any carrier element has a composite structure, comprising at least two constituents. It is a structure consisting of an assembly of at least two elements, such as, for example, an assembly comprising several elementary monofilaments or an assembly of a first layer of a first material and a second layer of a second material.

Regarding the material(s) making up the carrier element, in a first composition variant, any carrier element comprises a single material: for example, an elementary monofilament of a single material or an assembly comprising several elementary monofilaments of a same material. In a second composition variant, any carrier element comprises at least two materials. In this case, we have a composite structure from the materials point of view: for example, an assembly comprising elementary monofilaments of a first material and elementary monofilaments of a second material different from the first material. or a layer comprising elementary monofilaments or assemblies of elementary monofilaments embedded in a polymer matrix.

In a preferred embodiment, each wire element is a carrier wire element. Preferably, the supporting wire elements are identical, that is to say they have identical geometric characteristics and constituent materials.

These carrying wire elements are usually called guy wires. The advantage of using supporting wire elements is to have a supporting structure with a low mass and low hysteresis. The use of identical supporting wire elements makes it possible to have a homogeneous distribution of the forces between the supporting elements.

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

For example, each carrier wire element is a textile assembly comprising one or more elementary monofilaments, twisted together or not. Thus, in one embodiment, it will be possible to have an assembly in which the elementary monofilaments are substantially parallel to each other. In another embodiment, it is also possible to have an assembly in which the elementary monofilaments are wound in a helix. In yet another embodiment, each supporting wire element consists of an elementary monofilament. Each elementary monofilament has a diameter of between 5 and 20 μm, for example 10 μm.

In another embodiment, each carrier wire element is metallic, for example an assembly of metallic monofilaments, each metallic monofilament having a diameter typically less than 50 μm, for example 10 μm. In one embodiment, each supporting wire element consists of an assembly of several metal monofilaments. In another embodiment, each load-bearing wire element is made of a metallic monofilament.

In the embodiment using first and second floating soles, the load-bearing structure comprises first and second radially inner fabrics or knits for anchoring respectively the load-bearing elements of the first and second groups in each first and second radially inner fabric or knit, each first and second radially inner anchoring fabric or knit being attached to the radially outer surface of revolution of the sleeve of each first and second floating sole.

In the embodiment using first and second fixed flanges, each first and second fixed flange comprises a first and second radially outer fabric or knit for anchoring load-bearing elements of each first and second group, respectively, in each first and second fabric or knit. radially outward. Still in the embodiment using first and second fixed soles, each first and second fixed sole is of revolution around an axis substantially coinciding with the axis of rotation of the tire and comprises:
- a radially outer surface of revolution, and
- a radially inner surface of revolution,
each first and second fixed sole being attached to a radially inner surface of revolution of the crown via the radially outer surface of revolution.

This design advantageously makes it possible to have a supporting structure that can be partially manufactured independently and integrated in a single block during the manufacture of the tire according to the invention. The part of the load-bearing structure thus obtained, that is to say that comprising the load-bearing elements and the fabrics or knits, can be attached to the top and to the or each floating sole by direct application or else by bonding via of an adhesive layer and is co-crosslinked with the crown or the or each floating sole during the step of crosslinking the green tire blank.

In the case of a fabric, the latter comprises, in a manner known to those skilled in the art, a weave characterizing the interlacing of the wire elements of the first and second families. According to the embodiments, this weave is of the linen, serge or satin type. Preferably, in order to confer good mechanical properties in use in tires, the weave is of the fabric type. In the case of a knit, the latter includes interwoven loops. The mechanical characteristics of such fabrics or knits, such as their tensile stiffness and their tensile breaking strength, depend on the characteristics of the constituent elements of these fabrics or knits, such as, for textile yarn elements, the title, expressed in tex or g/1000 m, the tenacity, expressed in cN/tex, and the standard contraction, expressed in %, these wire elements being distributed according to a given density, expressed in number of wires/dm. All these characteristics are a function of the constituent material of the textile wire elements and of their manufacturing process.

In order to improve certain mechanical properties of the or each floating sole, the or each floating sole having a section of area A in any meridian section plane of the tire and a circumferential extension stiffness Ett, it will be sought to achieve a value of the product Ett x A as large as possible. When the tire is subjected to the nominal load, the load-bearing elements located radially opposite the running surface in contact with the tensioned ground displace radially inwards a portion of the floating sole located radially in line with the tread. running surface in contact with the ground but also cause a circumferential extension of the floating sole. If the floating sole has too low a circumferential extension stiffness, the floating sole will undergo a relatively large deformation and will not be able to effectively take up the axial forces between the load-bearing structure and the sidewall via the connecting element and thus participate in the improvement of the axial rigidity, nor will it be able to take up the radial forces effectively and thus participate in carrying the load.

In order to improve other mechanical properties of the or each floating footing, the or each floating footing having a circumferential bending inertia I, it will be sought to achieve a value of the product Ett x I ≥ as large as possible. When the tire is under load, the portion of the floating sole located radially in line with the running surface in contact with the ground is subjected to a force directed radially inwards which tends to flatten this portion of the tread. floating sole in the same way as the portion of the tread of the tire located radially in line with the running surface in contact with the ground. The flattening of the portion of the floating sole located radially in line with the tread surface in contact with the ground is dependent on the bending stiffness of the floating sole which is mainly dependent on the product of the circumferential extension stiffness and of the circumferential bending inertia of the floating sole. If the product is too weak, the flattening of the portion of the floating sole located radially in line with the running surface in contact with the ground will be relatively significant, which risks causing tensioning of the load-bearing elements located radially. in line with the running surface in contact with the ground. This tensioning would then exert on the portion of the floating sole located radially in line with the running surface in contact with the ground a force radially directed outwards which would then oppose the load port which would then be there. deteriorated. If the product exceeds a sufficient threshold, the flattening of the portion of the floating sole located radially in line with the running surface in contact with the ground is limited, which leads to a relaxation of the load-bearing elements and their buckling in compression and therefore an improved load port from the rest of the load-bearing structure for which the load-bearing elements are properly tensioned.

Furthermore, if the product of the circumferential tensile stiffness and the circumferential bending inertia of the floating sole is too low, there is a risk of the floating sole buckling and, under the effect of the repetition of rolling cycles , to cause a rupture of the floating footing.

Finally, if the product of the circumferential extension stiffness and the circumferential bending inertia of the floating sole is too low, there is a risk of excessively deforming the floating sole and causing a significant break in the curvature. when the tire passes in contact with the ground. However, the greater the break in curvature, the more shearing is caused in the sole, which leads to a strong increase in rolling resistance, which we wish to avoid.

In order to further improve other mechanical properties of the or each floating sole, the or each floating sole has a shear stiffness along the circumferential plane G, it will be sought to achieve a value of the product G x 2 x π x Rm x h also large as possible, product in which Rm is the mean radius of the or each floating footing, h the mean radial height of the or each floating footing.

Rm is the radial distance measured between the axis of rotation of the tire and the axial straight line located equidistant from the axial straight line passing through the radially outer surface of revolution and from the axial straight line passing through the radially inner surface of revolution of the floating sole.

When the load-bearing element closest axially to the median plane of the tire is tensioned and in order to transmit the corresponding force axially as far as the connecting element through the floating sole, it is preferable for the floating sole to have a shear stiffness along the highest possible circumferential plane.

In addition, in order to obtain the most regular running surface possible, it is preferable that all the load-bearing elements connected to the floating sole take up the forces as evenly as possible. If the floating sole has insufficient shear stiffness along the circumferential plane, some supporting elements could take up more forces than others and lead to locally higher tensions and irregular deformation of the running surface.

Following the generic description which has just been made, the invention will be better understood on reading the detailed description which will follow, given solely by way of non-limiting example and made with reference to the drawings in which:
- there is a view, in a meridian section plane parallel to the axis of rotation of the tire, of a tire according to the invention with no load applied and inflated to nominal pressure,
- there is a cut-away view of the tire from the illustrating the arrangement of the wire reinforcement elements in and under the crown,
- there is a detail view of zone III of the ,
- there is a view analogous to that of of the entire tire subjected to a nominal load and inflated to the nominal pressure, and
- there is a view analogous to that of of a tire of the state of the art described in WO2019/092343 subjected to a nominal load and inflated to the nominal pressure.

In the figures relating to the tire, an X, Y, Z mark has been shown corresponding to the usual axial (Y), radial (Z) and circumferential (X) directions respectively of a tire.

We represented on the a tire, in accordance with the invention and designated by the general reference 10. The tire 10 has a substantially toroidal shape around an axis of revolution substantially parallel to the axial direction Y. The tire 10 is intended for a passenger vehicle and has dimensions 255/35ZR19 XL (XL meaning Extra Load) having a load index equal to 96. In the various figures, the tire 10 is shown in new condition, that is to say not yet having rolled. In accordance with the European Tire and Rim Technical Organization or “ETRTO” standard, 2019, the tire 10 is intended to be inflated to a nominal pressure equal to 2.5 bars and to be subjected to a nominal load equal to 630 kg.

The tire 10 comprises a crown 12 comprising a tread 14 intended to come into contact with the ground during rolling and a crown reinforcement 16 extending into the crown 12 in the circumferential direction X. The tire 10 also comprises a layer sealing 18 to an inflation gas.

The crown reinforcement 16 comprises a working reinforcement 20 and a hooping reinforcement 22. The working reinforcement 16 comprises at least one working layer and here comprises two working layers 24, 26. In this case, the working reinforcement 16 consists of two working layers 24, 26. The radially inner working layer 24 is arranged radially inside the radially outer working layer 26.

The hooping reinforcement 22 comprises at least one hooping layer and here comprises a hooping layer 28. The hooping reinforcement 22 here consists of the hooping layer 28.

The crown reinforcement 16 is surmounted radially by the tread 14. Here, the hooping reinforcement 22, here the hooping layer 28, is arranged radially outside the working reinforcement 20 and is therefore radially inserted between the working reinforcement 20 and the tread 14. Preferably, it may be envisaged that the hooping reinforcement 22 has an axial width at least as large as the axial width of the working reinforcement 20 and, in this case, in the embodiment illustrated in , the hooping reinforcement 22 has an axial width greater than the axial width of the working reinforcement 20.

The tire 10 comprises two sidewalls 30 extending the crown 12 radially inwards. The tire 10 further comprises two beads 32 extending the sidewalls 30 radially inwards. Each sidewall 30 connects each bead 32 to the crown 12. The assembly formed by the crown 12, the two sidewalls 30 and the two beads 32 is intended to delimit an internal toric cavity 33 once the tire 10 is mounted on a mounting support 35 , here a standard rim within the meaning of the standard of the European Tire and Rim Technical Organization or “ETRTO”, 2019. Each bead is intended to come into contact with the mounting support 35 as shown in the .

The tire 10 comprises a carcass reinforcement 34 anchored in each bead 32, in this case is wrapped around a circumferential reinforcement element 40, here a bead wire 40. The carcass reinforcement 34 extends in each sidewall 30 and radially internally to 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 and here comprises a single carcass layer 36. In this case, the carcass reinforcement 34 consists of the single carcass layer 36.

Each working layer 24, 26, hooping 28 and carcass 36 comprises an elastomeric matrix in which are embedded one or more wire reinforcing elements of the corresponding layer. We will now describe these layers with reference to the .

The hooping reinforcement 22, here the hooping layer 28, is delimited axially by two axial edges 28A, 28B of the hooping reinforcement 22. The hooping reinforcement 22 comprises one or more hooping wire reinforcing elements 280 wound circumferentially helically so as to extend axially from the axial edge 28A to the other axial edge 28B of the hooping layer 28 along a main direction D0 of each hooping wire reinforcement element 280. The main direction D0 forms, with the direction circumferential X of the tire 10, an angle AF, in absolute value, less than or equal to 10°, preferably less than or equal to 7° and more preferably less than or equal to 5°. Here, AF=-5°. The hooping layer 28 comprises a density of 98 wire reinforcing hooping elements per decimeter of hooping layer, this density being measured perpendicular to the direction D0.

The radially inner working layer 24 is delimited axially by two axial edges 24A, 24B. The radially inner working layer 24 comprises working wire reinforcement elements 240 extending axially from the axial edge 24A to the other axial edge 24B, one substantially parallel to the other in a 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 working wire reinforcement elements 260 extending axially from the axial edge 26A to the other axial edge 26B, one substantially parallel to the other in a main direction D2. The main direction D1 along which each wired working reinforcement element 240 of the radially inner working layer 24 extends and the main direction D2 along which each wired working reinforcement element 260 extends from the other of the radially inner working layer 24 radially outer working 26 form, with the circumferential direction X of the tire 10, angles AT1 and AT2 respectively of opposite orientations. Each main direction D1, D2 forms, with the circumferential direction X of the tire 10, an angle AT1, AT2 respectively, in absolute value, strictly greater than 10°, preferably ranging from 15° to 50° and more preferably ranging from 15° at 30°. Here, AT1=-26° and AT2=+26°.

The carcass layer 36 is delimited axially by two axial edges 36A, 36B. The carcass layer 36 comprises carcass wire reinforcement elements 340 extending axially from the axial edge 36A to the other axial edge 36B of the carcass layer 36 in a main direction D3 forming with the circumferential direction X of the tire 10, an angle AC, in absolute value, greater than or equal to 60°, preferably ranging from 80° to 90° and here AC=+90°.

Each hooping wire reinforcement element 280 conventionally comprises two multifilament strands comprising a multifilament strand consisting of a yarn of aliphatic polyamide monofilaments, here of nylon with a denier equal to 140 tex and a multifilament strand consisting of a yarn of monofilaments aromatic polyamide, here aramid with a titer equal to 167 tex, these two multifilament strands being twisted individually at 290 turns per meter in one direction and then twisted together at 290 turns per meter in the opposite direction. These two multifilament strands are wound in a helix around each other. Of course, any other hooping wire reinforcement element known to those skilled in the art may be used.

Each working wire reinforcement element 180 is an assembly of four steel monofilaments comprising an inner layer of two steel monofilaments initially helically wound at an infinite pitch and an outer layer of two steel monofilaments initially helically wound at 14 pitch. 3 mm in one direction, the four monofilaments then being wound at a pitch of 14.3 mm without the opposite direction, each steel monofilament having a diameter equal to 0.26 mm. In another variant, each working wire reinforcement element 180 consists of a steel monofilament having a diameter equal to 0.30 mm. In yet another variant, each working wire reinforcement element is an assembly of two monofilaments wound together in a helix having a diameter equal to 0.30 mm. More generally, steel monofilaments have diameters ranging from 0.25 mm to 0.32 mm. Of course, any other working wire reinforcement element known to those skilled in the art can be used.

Each carcass wire reinforcement element 340 conventionally comprises two multifilament strands, each multifilament strand being made up of a yarn of polyester monofilaments, here of PET, these two multifilament strands being twisted individually at 270 turns per meter in one direction then helixed together at 270 rpm in the opposite direction. Each of these multifilament strands has a titer equal to 334 tex. In other variants, it is possible to use titles equal to 144 tex and twists equal to 420 turns per meter or titles equal to 220 tex and twists equal to 240 turns per meter.

With reference to the , the tread 14 comprises a rolling surface 38 via which the tread 14 comes into contact with the road surface. The rolling surface 38 is intended to come into contact with the ground when the tire 10 is rolling on the ground and is delimited axially by first and second axial ends 41, 42 passing through each point N arranged on either side of the median plane M and for which the angle between the tangent T to the running surface 38 and a straight line R parallel to the axial direction Y passing through this point is equal to 30°.

Each straight line 43, 44 perpendicular to each tangent T delimits the crown 12 of the tire from each sidewall 30. Each sidewall 30 is also radially delimited internally by two axial straight lines 45, 46 passing through the radially outer end of each bead 32 which is the radially outermost point in contact with mounting bracket 35.

The tire 10 comprises a load-bearing structure 50 comprising first and second floating soles 52, 54 movable independently of one another and arranged radially with respect to the crown 12. The first and second floating soles 52, 54 are symmetrical with each other. on the other relative to the median plane M of the tire 10.

The load-bearing structure 50 also comprises first and second flanges 56, 58 fixed with respect to the crown and arranged radially inside the crown 12. The first and second fixed flanges 56, 58 are separate from each other and arranged radially to the outside respectively of each first and second floating sole 52, 54. The first and second fixed soles 56, 58 are symmetrical to one another with respect to the median plane M of the tire 10.

The load-bearing structure 50 also comprises first and second groups of load-bearing elements 64, 66. Each first and second floating footing 52, 54 is connected to the top 12 via respectively each first and second group of load-bearing elements 64, 66. In this case, the load-bearing elements 64, 66 respectively of each first and second group of load-bearing elements interconnect respectively each first and second fixed flange 56, 58 and each first and second floating flange 52, 54. Each element carrier 64, 66 comprises a wire carrier element 67 extending in a main direction between each first and second floating soles 52, 54 and the crown 12 forming, with the radial direction Z of the tire, an angle C less than or equal to 50° .

Each carrying wire element is an assembly of several elementary monofilaments made of polyester, here of polyethylene terephthalate (PET), having a linear density equal to 55 tex and a tenacity equal to 54 cN/tex. All the carrying wire elements 67 are identical. The wire bearing elements are present at a density of 85,000 wires/m ² .

The load-bearing structure 50 also comprises first and second connecting elements 68, 70 between each floating flange 52, 54 and each sidewall 30. The first and second connecting elements 68, 70 are symmetrical to each other with respect to each other. to the median plane M of the tire 10. Each first and second connecting element 68, 70 has a shape of revolution around the axis of revolution of the tire and comprises wire reinforcing elements (not shown) embedded in an elastomeric matrix, the wire reinforcing elements of each first and second connecting element 68, 70 extending between the connection zones 80 and 82 along a main direction forming an angle substantially equal to 90° with the circumferential direction X of the tire 10. Each element of wire reinforcement is here an assembly of two strands of PET each having a titer equal to 184 tex. The density of these wire reinforcement elements is equal to 104 wire reinforcement elements per decimetre of connecting element, this density being measured in the circumferential direction X.

With reference to and 3, each first and second floating sole 52, 54 comprises a sleeve 52', 54' of revolution around an axis substantially coinciding with the axis of rotation of the tire 10. Each first and second sleeve 52', 54' comprises a radially outer surface of revolution 52RE, 54RE and a radially inner surface of revolution 52RI, 54RI. Each sleeve 52', 54' also includes an axially outer end 52AE, 54AE and an axially inner end 52AI, 54AI.

Each first and second floating sole 52, 54, here each first and second sleeve 52', 54', has an axial width WI greater than or equal to 0.05 times the nominal section width S of the tire 10 and less than or equal to 0.4 times the nominal section width S of the tire 10. In this case, WI=60 mm and S=255 mm. Each first and second sleeve 52', 54' has a radial height h equal to 2 mm. The axial width WI and the radial height h are constant over the circumference of the tire 10.

In the illustrated embodiment, each first and second sleeve 52', 54' is made of aliphatic polyamide, here of nylon PA6 of reference "Grilon F50 nat 6368" extruded into a profile. The modulus at ambient humidity is equal to 750 MPa.

The supporting structure 50 also comprises first and second radially inner fabrics or knits 72, 74 for anchoring respectively the supporting elements 64, 66 of the first and second groups in each first and second radially inner fabrics or knits 72, 74. In this case, each first and second fabric or knit 72, 74 is a woven fabric of the canvas type comprising polyester warp wire elements (PET having a count of 110 Tex having a twist of 60 turns per meter) and weft wire elements made of polyester (PET with a titer of 167 Tex with a twist of 60 turns per meter). Each first and second radially inner anchoring fabric or knit 56, 58 is attached, for example by gluing, to the radially outer surface of revolution 52RE, 54RE of the sleeve 52', 54' of each first and second floating sole 52, 54 .

With reference to the , each first and second fixed sole 56, 58 is of revolution about an axis substantially coinciding with the axis of rotation of the tire 10. Each first and second fixed sole 56, 58 comprises a radially outer surface of revolution 56RE, 58RE and a radially inner surface of revolution 56RI, 58RI. Each first and second fixed shoe 56, 58 also includes an axially outer end 56AE, 58AE and an axially inner end 56AI, 58AI. Each first and second fixed sole 56, 58 has an axial width WE greater than or equal to 0.05 times the nominal section width S of the tire 10 and less than or equal to 0.4 times the nominal section width S of the tire 10. , WE=60 mm.

Each first and second fixed sole 56, 58 comprises a first and second radially outer fabric or knit 76, 78 for anchoring bearing elements 64, 66 of each first and second group respectively in each first and second radially outer fabric or knit 76, 78. In this case, each first and second fabric or knit 76, 78 is identical to the first and second fabrics 72, 74. Each first and second fixed flange 56, 58 is attached, for example by gluing, to a radially inner surface 84 of the top 12 via each radially outer surface of revolution 56RE, 58RE.

Each first and second connecting element 68, 70 is connected to each flank 30 via a connection zone 80 between each first and second connecting element 68, 70 and each flank 30 and having a connection point radially more interior 81.

Each first and second connecting element 68, 70 is connected to each first and second floating sole 52, 54 via a connection zone 82 between each first and second connecting element 68, 70 and each first and second sole floating 52, 54 and having an axially outermost connection point 83.

In any meridian section plane of the tire 10, and for example in the meridian section plane of the , the radially innermost connection point 81 of the connection zone 80 between each first and second connecting element 68, 70 and each flank 30 is located radially outside the axially outermost connection point 83 of the zone connection 82 between each first and second connecting element 68, 70 and each first and second floating sole 52, 54.

The radially innermost connection point 81 of the connection zone 80 each first and second connecting element 68, 70 and each flank 30 is arranged radially at a radial distance B ranging from 0.1 x H to 0.5 x H of the radially outermost point U of the circumferential reinforcement element 40 with H being the section height of the tire 10. Here H=89 mm and B=13 mm.

Each first and second connecting element 68, 70 extends in a general direction G oriented radially and axially inward when moving along each first and second connecting element 68, 70 from the connection point 81 the most radially interior of the connection zone 80 towards the point of connection 83 the most axially exterior of the connection zone 82.

Each first and second connecting element 68, 70 is attached, for example by gluing, to each radially inner surface of revolution 52RI, 54RI so as to bear radially on each axially outer end 52AE, 54AE of the sleeve 52', 54' .

On the , the tire 10 is inflated to the nominal pressure and subjected to its nominal load. The tire 10 is in contact with a road surface 90 via the tread surface 38. The tire 10 is arranged so that at least a part 640, 660 of the bearing elements 64, 66 located radially to the opposite the rolling surface 38 in contact with the ground is in tension and that at least a part 64D, 66D of the supporting elements 64, 66 located radially in line with the rolling surface 38 in contact with the ground is subjected to buckling in compression. The tensioning of the part 64O, 66O of the bearing elements 64, 66 is represented by the forces Te exerted by the portion 12O of the crown 12 located radially opposite the running surface 38 in contact with the ground on each element carrier 64, 66 and the compression of the part 64D, 66D of the carrier elements 64, 66 is represented by the force Tc exerted by the portion 12D of the crown 12 located radially in line with the running surface 38 in contact with the ground on each carrier element 64, 66. The compression of the part 64D, 66D of the carrier elements 64, 66 is the result of the deflection of the tire 10 subjected to its load and the radially outward displacement of each portion 52O, 54O of each first and second floating sole 52, 54 located radially opposite the tread surface 38 in contact with the ground, the deflection being much greater than the radially inward displacement of each portion 52O, 54O.

The part 64O, 66O of the carrier elements 64, 66 located radially opposite the running surface 38 in contact with the ground is under tension so as to move radially outwards each portion 52O, 54O of each first and second floating sole 52 54 located radially opposite the running surface 38 in contact with the ground. The displacement of the portions 52O, 54O of each first and second floating flange 52, 54 with respect to the equilibrium position is represented by the displacement De. In this case, under a load of 557 daN at a pressure of 2.5 bars, De is approximately equal to 1.2 mm.

The part 64O, 66O of the bearing elements 64, 66 located radially opposite the rolling surface 38 in contact with the ground is also under tension so as to move radially inwards a portion 52D, 54D of each first and second floating sole 52, 54 located radially in line with the rolling surface 38 in contact with the ground. The displacement of the portions 52D, 54D of each first and second floating sole 52, 54 relative to the equilibrium position is represented by the displacement Di. Under a load of 557 daN and at a pressure of 2.5 bars, Di is approximately equal to 4.6 mm.

The presence of the first and second connecting elements 68, 70 allows an arrangement of the support structure 50 such that, under the effect of the radially inward displacement Di of each portion 52D, 54D of each first and second floating flange 52, 54 located radially in line with the running surface 38 in contact with the ground, each first and second connecting element 68, 70 exerts on at least one radial portion 30D of the sidewall 30 located radially in line with the running surface 38 in contact with the ground and under the preceding drift stress, a tensile force Tr directed axially and radially inwards. On the , the portion 30D is delimited by each straight line 43, 44 and by an axial straight line passing through the radially outermost point 92 of the connection zone 80. The tensile force Tr applied in the connection zone 80 makes it possible to generate a radial displacement Ds inwards of an axially outer portion of the crown 12, which makes it possible, in accordance with the invention, to reduce the pressure exerted by the road surface 90 on the shoulder of the tire 10.

Under a load of 800 daN at a pressure of 1.8 bar, with a drift angle of 9° and a camber angle of 3°, which constitutes a relatively high stress, it was thus possible to measure that the load carried by the sidewall of the tire was 170 daN for the tire described in WO2019/092343, and 47 daN for the tire according to the invention.

Another consequence of the presence of the first and second connecting elements 68, 70 is that it allows an arrangement of the supporting structure 50 such that, under the effect of the radially inward displacement Di of each portion 52D, 54D of each first and second floating sole 52, 54 located radially in line with the running surface 38 in contact with the ground, each portion 32D of each bead 32 located radially in line with the running surface 38 in contact with the ground is, under the previous drift stress, put in compression between each first and second connecting element 68, 70 and the mounting support 35.

Unlike the tire according to the invention, the tire described in WO2019/092343 and illustrated in the comprises first and second connecting elements connected to each bead of the tire and arranged so that, under the effect of the radially inward displacement of the portion of the floating sole located radially in line with the rolling surface in contact with the ground, each first and second connecting element deforms in bending radially inwards without exerting a tensile force on each side. Indeed, on the one hand, each first and second connecting element being, as described in WO2019/092343, a flexible element connected to each bead which is a relatively rigid element with respect to each first and second connecting element, the radial displacement towards the inside of the portion of the floating sole located radially in line with the running surface in contact with the ground causes deformation by bending of each first and second connecting element and no force is transmitted to the bead and even less on the flank.

On the other hand, the tire described in WO2019/092343 is such that the most radially inner connection point of the connection zone between each connecting element and each bead is located radially inside the most axially connecting point exterior of the connection zone between each connecting element and each floating footing. Thus, in order to be able to exert a force oriented radially inwards, each floating sole of the tire described in WO2019/092343 would have to be moved radially to a radial dimension such that the radially innermost connection point of the connection zone between each connecting element and each bead is located radially outside the axially outermost connection point of the connection zone between each connecting element and each floating flange. Such a configuration is impossible due to the arrangement of each first and second connecting element described in WO2019/092343 which would then cause tensioning of the supporting elements located radially in line with the running surface in contact with the ground and therefore lifting of the running surface in contact with the ground.

The invention is not limited to the embodiment described above.

Indeed, it is possible to envisage a supporting structure in which the supporting elements are anchored directly in each sleeve 52', 54' without the intermediary of a fabric or a knit.

It should be noted that the advantageous properties conferred by the values of circumferential extension stiffness and shear stiffness in the circumferential direction of the sleeve and described in the present application can also be obtained in the case of a tire as described in WO2019/ 092343 also using the values of circumferential extension stiffness and shear stiffness in the circumferential direction described in the present application.

Claims (14)

A tire (10) intended to be inflated to a nominal pressure and to be subjected to a nominal load, comprising:
- a crown (12) extended radially inwards, by two sides (30) then by two beads (32), each bead being intended to come into contact with a mounting support (35),
- a bearing structure (50) comprising bearing elements (64, 66) and a floating sole (52, 54) arranged radially inside the crown (12), the floating sole being connected to the crown (12) by the intermediate carrier elements (64, 66),
the tire (10) being arranged so that, when the tire (10) is inflated to a nominal pressure and is subjected to a nominal load and is in contact with a road surface (90) via a running surface (38), at least a portion of the load-bearing elements (64, 66) located radially opposite the running surface (38) in contact with the ground are in tension so as to move radially inward a portion (52D, 54D) of the floating sole (52, 54) located radially in line with the running surface (38) in contact with the ground,
characterized in that the supporting structure (50) comprises at least one connecting element (68, 70) between the floating sole (52, 54) and at least one of the sidewalls (30) arranged so that, under the effect of the movement (Di) radially inwards of the portion (52D, 54D) of the floating sole (52, 54) located radially in line with the running surface (38) in contact with the ground, the connecting element ( 68, 70) is capable of exerting on at least one radial portion (30D) of the sidewall (30) located radially in line with the rolling surface (38) in contact with the ground a traction force (Tr) directed at least radially towards the inside. Tire (10) according to the preceding claim, in which the or each connecting element is arranged so that, under the effect of the radially inward displacement of the portion of the floating sole located radially in line with the running surface (38) in contact with the ground, the or each connecting element is able to exert on the radial portion (30D) of the or each sidewall (30) located radially in line with the running surface (38) in contact with the ground a tensile force (Tr) directed axially and radially inwards. A tire (10) according to any preceding claim, wherein the or each connecting element (68, 70) is arranged such that when the tire (10) is inflated to nominal pressure and is subjected to the load nominal and is in contact with a road surface (90) via the running surface (38), under the effect of the radially inward displacement of the portion (52D, 54D) of the each floating sole (52, 54) located radially in line with the running surface (38) in contact with the ground, at least one portion (32D) of the or each bead (32) located radially in line with the running surface (38) in contact with the ground is compressed between the or each connecting element (68, 70) and the mounting bracket (35). Tire (10) according to any one of the preceding claims, arranged so that, when the tire (10) is inflated to the nominal pressure and is subjected to the nominal load and is in contact with the rolling ground (90) by the intermediate the rolling surface (38), at least a part of the support elements (64, 66) located radially opposite the rolling surface (38) in contact with the ground are in tension so as to move radially towards the outside a portion (52O, 54O) of the or each floating sole (52, 54) located radially opposite the running surface (38) in contact with the ground. Tire (10) according to any one of the preceding claims, arranged so that, when the tire (10) is inflated to the nominal pressure and is subjected to the nominal load and is in contact with the rolling ground (90) by the intermediate the running surface (38), at least a part of the supporting elements (64D, 66D) located radially in line with the running surface (38) in contact with the ground is subjected to compression buckling. A tire (10) according to any one of the preceding claims, in which, in any meridian section plane of the tire (10), the radially innermost connection point (81) of the connection zone (80) between the each connecting element (68, 70) and the or each flank (30) is located radially outside the axially outermost connection point (83) of the connecting zone (82) between the or each connecting element (68, 70) and the or each floating sole (52, 54). A tire (10) according to any one of the preceding claims, in which, each bead (32) comprising a circumferential reinforcement element (40), the radially innermost connection point (81) of the connection zone (80) between the or each connecting element (68, 70) and the or each flank (30) is arranged radially at a radial distance (B) ranging from 0.1 x H to 0.5 x H from the radially outermost point ( U) of the circumferential reinforcement element (40) or of the radially outermost circumferential reinforcement element, H being the section height of the tire (10). Tire (10) according to any one of the preceding claims, in which, in any meridian section plane of the tire (10), the or each connecting element (68, 70) extends in a general direction (G) oriented radially and axially inward as one moves along the or each connecting member (68, 70) from the radially innermost connection point (81) of the connection area (80) between the or each connecting element (68, 70) and the or each flank (30) towards the axially outermost connection point (83) of the connecting zone (83) between the or each connecting element (68, 70) and the or each floating sole (52, 54). A tire (10) according to any one of the preceding claims, in which the support structure (50) comprises first and second connecting elements (68, 70) between the floating sole (52, 54) and each sidewall (30) arranged so that, under the effect of the radially inward displacement of the portion (52D, 54D) of the floating sole (52, 54) located radially in line with the running surface (38) in contact with the ground, each first and second connecting element (68, 70) is capable of exerting on at least one radial portion (30D) of each sidewall (30) located radially in line with the running surface (38) in contact with the ground a force tension (Tr) directed at least radially inward. A tire (10) according to any preceding claim, wherein the supporting structure (50) comprises first and second groups of supporting elements (64, 66) and first and second independently movable floating shoes (52, 54). from each other and arranged radially inside the crown (12), each first and second floating sole (52, 54) being connected to the crown (12) via respectively each first and second group of supporting elements (64, 66). Tire (10) according to the preceding claim, in which the bearing structure (50) comprises first and second flanges (56, 58) separate from each other, fixed with respect to the crown (12) and arranged radially to the inside the crown (12) and radially outside respectively of each first and second floating sole (52, 54), the support elements (64, 66) respectively of each first and second group of support elements (64, 66 ) interconnecting respectively each first and second fixed sole (56, 58) and each first and second floating sole (52, 54). Tire (10) according to any one of the preceding claims, in which the or each floating sole (52, 54) comprises a sleeve (52', 54') of revolution around an axis substantially coinciding with the axis of rotation of the tire (10) and comprising:
- a surface (52RE, 54RE) of radially outer revolution, and
- a surface (52RI, 54RI) of radially internal revolution,
the connecting element (68, 70) being attached to the surface (52RI, 54RI) of radially inner revolution so as to bear radially on an axially outer end (52AE, 54AE) of the sleeve (52', 54') . Tire (10) according to the preceding claim, in which the supporting structure (50) comprises a radially inner fabric or knit for anchoring the supporting elements (64, 66), the radially inner fabric or knit (72, 74) being attached to the radially outer surface of revolution (52RE, 54RE) of the sleeve (52', 54') of the floating shoe (52, 54). A tire (10) according to any one of the preceding claims, in which the bearing structure (50) comprises a flange fixed (56, 58) with respect to the crown (12) arranged radially inside the crown (12) and radially outside the or each floating sole (52, 54), the load-bearing elements (64, 66) interconnect the fixed sole (56, 58) and the or each floating sole (52, 54).