IMPROVED ADAPTER AND ROLLING ARRANGEMENT USING SUCH AN ADAPTER

Description

[0001] The invention relates to an expander for a rolling assembly consisting of a tire and a rigid rim connected together by an expander capable of offering a certain elastic flexibility during an impact suffered during rolling, as well as a rolling assembly comprising it. A tire comprises, as is known, two beads intended to be mounted on the seats of a rim. The present invention relates to rolling assemblies in which a tire bead is not mounted directly on a rigid rim, but is mounted on a flexible expander, an expander which is itself mounted on a rigid rim.

[0002] A tire, a rim, and an expander referred to in the present invention are usually described by a representation in a meridian plane, i.e., a plane containing the axis of rotation of the tire. All these products (the tire, the rim, the expander) are objects having a geometry of revolution relative to the axis of rotation of the tire. The radial and axial directions respectively designate the directions, the first, perpendicular to the axis of rotation of the tire, and the second, parallel to the axis of rotation of the tire. In the following, the expressions "radially" and "axially" mean respectively "in a radial direction" and "in the axial direction". The expressions "radially inner, respectively radially outer" mean "closer, respectively further, from the axis of rotation of the tire, in a radial direction".A median plane is a plane perpendicular to the tire's axis of rotation, positioned axially so as to intersect the tread surface substantially midway between the beads of a tire. The expressions "axially inner, respectively axially outer" mean "closer, respectively further, from the median plane of the tire, in the axial direction". Furthermore, "radial cut" or "radial section" means a cut or section along a plane that contains the tire's axis of rotation. "Meridian cut" means a cut made with a meridian plane and, by meridian plane, means a plane parallel to and containing the tire's axis of rotation and perpendicular to the circumferential direction.By "circumferentially" is understood, in a circumferential direction, the direction which is substantially perpendicular to both the axial direction and a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

[0003] Document WO2016 / 046197 describes an example of a flexible expander arranged between a tire bead and a rim. The rolling assembly according to this document comprises a tire, a rim and two identical expanders. Considering the language conventions recalled above, and referring to the way in which an expander is mounted on a rim, such an expander comprises, axially from the inside to the outside, an axially inner end called the expander bead and intended to ensure the attachment of the expander to the rim. Such an expander also comprises an axially outer end intended to receive and axially immobilize a tire bead. A body provided with a reinforcing reinforcement connects the two ends, respectively axially inner and axially outer.

[0004] The extenders are mounted on a rim which is a metal part, most of the time made of aluminum. The rim has a rim hook on each side intended to ensure in particular the immobilization in the axial direction of the extender. A flexible extender must, on the one hand, have a certain elastic flexibility for example when hitting a sidewalk or when passing through a "pothole" and, on the other hand, it must have sufficient rigidity when rolling in order to give the vehicle correct behavior. For this, such an extender is made of elastomeric materials, materials close to those used for the manufacture of the tire from which it borrows its appearance.

[0005] Thus, a rolling assembly comprising a rim, and a tire mounted on the rim by means of two extenders, presents the appearance of a wheel smaller in diameter than that of a conventional wheel used with a tire of the same size. However, the current design trend is to have a wheel as large as possible, at least in its visual appearance.

[0006] A solution has been proposed in document WO201807751 in the name of the applicant, a solution which consists of adding a trim ring to the visible part of the extender. This trim ring is chosen to be elastically deformable, it is made of a single piece and it is fixed by means of a mechanical attachment or by gluing over the entire periphery of the visible part of the extender. However, it has been found that the flexibility requirement for the trim ring leads to the constraint of the choice of its material. Thus, when a metallic material is chosen for the trim ring, the deformation undergone by the extender and, consequently, by the trim ring, leaves permanent traces on the ring due to local plastic deformation. We then resort instead to the use of flexible synthetic materials.In this case, due to their flexibility, these soft synthetic materials must be dyed in the mass (instead of being covered with paint, as in the case of metallic surfaces). This type of coloring cannot confer a shiny appearance, as desired by vehicle wheel designers. In addition, for practical reasons of production, generally by injection into a mold, and to compensate for the rather low modulus of elasticity of the synthetic material constituting the trim ring, the thickness of this ring is quite significant and therefore causes greater exposure to grating against a pavement. As a result, this creates problems of surface scratching of the trim ring, or even loss of it following its detachment from the support.

[0007] The aim of the invention is to overcome the aforementioned drawbacks and to propose an original styling solution for an extender allowing robust fixing of design elements, even in the event of large deformations of the extender or when the wheel rotates at high speed, while providing a visual perception of a large diameter wheel.

[0008] The invention therefore relates to an expander for a rolling assembly with an axis of rotation XX' comprising a tire, having two beads and a rim, the expander being intended to ensure the junction between one of the beads and the rim, said expander comprising an axially inner end, an axially outer end and a body oriented mainly axially and arranged between said axially outer end and said axially inner end, so that, when mounted within the assembly, said axially inner end is intended to be immobilized on said rim using an inner reinforcing element, said axially outer end comprising an outer reinforcing element is intended to receive a tire bead,characterized in that the axially outer end comprises a visible face made so as to reveal the axially outer faces of several inserts fixed to the extender and distributed around the circumference of said visible face.,

[0009] By extender according to the invention, we understand a flexible extender, capable of elastically deforming mainly in a radial direction when it is subjected to a force, such as that experienced when the wheel hits a pavement. According to the invention, the extender comprises several fixed (or non-removable) mounted inserts distributed over the circumference of said visible face of the extender (we understand that the face is visible when looking at a wheel mounted on the vehicle, the wheel comprising an extender mounted on the rim), so that the inserts can also be visible. The inserts of the extender can be glued individually in housings made of an elastomeric material obtained after the curing of the extender or they can be arranged in the curing mold beforehand and secured to the extender during the curing thereof.

[0010] By inserts distributed around the circumference, it is understood that two inserts are located side by side so that a space remains between the two, allowing the creation of bridges of elastomeric material between the inserts, and this over the entire circumference of the visible face of the axially outer end of the expander. The visible face is preferably a front face of the expander. The inserts according to the invention are independent rigid inserts or connected to each other by deformable links, while being integral with the expander. Thus, the inserts being rather rigid, for example metallic, the zone which separates two inserts fixed in their respective cavities is, itself, flexible. Preferably, the inserts and the spaces separating two adjacent inserts are chosen to be fairly small, their sizes being of the same order of magnitude as the local deformation undergone by the expander in the event of an impact against a sidewalk for example.This allows the extender to absorb deformation in the event of an impact to the wheel, without affecting the external appearance of the extender and therefore while maintaining its initial design. Thus, in the event of an impact to the wheel, the flexible extender deforms and the rigid inserts attached to it retain their shape and configuration.

[0011] The solution of the invention is compatible with high levels of deformation encountered for example during an impact against a pavement of a rolling assembly comprising an extender of the invention and this due to the dissociation between them of the elements added to the visible external surface of the extender. This dissociation makes it possible to cut off the transmission of stresses linked to an imposed deformation, present in a trim ring produced in the form of a single piece, stresses all the greater as the modulus of elasticity of the part concerned is high.

[0012] Said inserts may be made of a metallic material. Thus, by arranging a plurality of inserts on the circumference of the axially outer end of the extender, this will make it possible to give it an overall metallic appearance and to give the wheel the appearance of a large diameter wheel.

[0013] Said visible surface may be the axially outermost face of said axially outer end and the inserts may protrude relative to this face. Thus, when the inserts protrude relative to the axially outermost face of the extender, they manage to protect the elastomeric surfaces of the extender, surfaces which are therefore further back, during sidewalk raking. Preferably, the visible surface means that of the axially outer face of the outer extender. The inner extender may be identical or different to the outer extender, for example when it is different, it does not include added inserts.

[0014] Said inserts can be made in the form of several individual elements connected together at their base. This facilitates their attachment to the expander, particularly during an overmolding operation during cooking.

[0015] The inserts can be separate individual elements. This embodiment is more suitable for gluing the inserts into the designated recesses on the expander after baking.

[0016] Said inserts may have an elongated shape, their length being at most equal to the width of said visible face of the axially outer end of the extender. The inserts thus occupy part of the width of the circumference of the axially outer end of the extender, which makes it possible to obtain a visual appearance of a large diameter wheel, even by increasing the space between two adjacent inserts.

[0017] Said inserts may be uniformly distributed around the circumference of said visible face of the expander. The inserts may be spaced apart by a pitch greater or less than their width.

[0018] The housings of said inserts may each have several notches made in their walls. This makes it possible to fill the notches of the impression or the housing of the insert with adhesive, while controlling the thickness of the adhesive layer.

[0019] Said inserts can be arranged in a radial direction or in a direction which forms a constant acute angle with the radial direction of the expander. In this case, the inserts can be parallel to each other in groups of inserts, they preferably form a constant angle with the radial direction.

[0020] The object of the invention is also achieved with a method of manufacturing an expander according to the invention, which comprises a step of molding said inserts in the same mold as that for molding the expander. This makes it possible to obtain the final object during a single baking operation of the expander and insert assembly.

[0021] The object of the invention is also achieved with a method of manufacturing an expander according to the invention, which comprises a step of gluing said inserts into housings provided for this purpose in the axially outer end of the expander. This makes it possible to obtain an expander of the invention by gluing the inserts into housings obtained during a prior step of curing the expander.

[0022] The object of the invention is also achieved with a rolling assembly with an axis of rotation XX' comprising a tire, having two beads, a rim and an extender according to the invention intended to ensure the junction between one of the beads and the rim.

[0023] The invention is described below with the aid of figures 1 to 10 , given for illustration purposes only: there figure 1 is a meridian sectional view of a rolling assembly comprising an extender according to the invention; the figure 2is a partial perspective view of an extender of the invention; the figure 3 is a partial front view of a visible face of the extender according to a first embodiment of the invention and detail AA is a sectional view along plane AA; figure 4 is a partial perspective view of a visible face of the extender according to a variant of the embodiment of the figure 3 ; there Figure 5 is a partial perspective view of the extender according to a second embodiment of the invention; the figure 6 is a partial perspective view of the inserts used to obtain the extender of the Figure 5 ; THE figures 7, 8 and 9 illustrate by partial front views different extenders of the invention; the figure 10 illustrates an insert in its housing within an extender of the invention.

[0024] In the various figures, identical or similar elements bear the same reference. Their description is therefore not systematically repeated.

[0025] Any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​from more than a to less than b (i.e., excluding the limits a and b), while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​from a to b (i.e., including the strict limits a and b).

[0026] There figure 1shows in a meridian sectional view a rolling assembly according to the invention. This assembly has an axis of rotation X-X', it comprises two expanders 1, a tire 2 and a rim 5. The tire 2 has two beads 21. The rim 5 has two rim seats 51, each extended by a rim flange 52. The rim flange 52 has a radially outer bearing face 53 intended to serve as a support for the body of the expander. The bearing face 53 of the rim flange 52 is in contact with the expander 1 when the tire is mounted on the expanders and the latter are mounted on the rim, the tire being inflated to the nominal pressure.

[0027] The extender 1 comprises an axially inner end 10 intended to be mounted on one of said rim seats 51. It comprises an axially outer end 11 provided with an outer reinforcing element 15, which is annular in shape, produced for example on the basis of a cable winding, as well as a body 12 oriented substantially axially and arranged between said axially outer end 11 and said axially inner end 10. The axially inner end 10 of the extender has an axial positioning face substantially perpendicular to the axis of rotation X-X', and is immobilized by being pressed axially against the rim flange 52 under the effect of the inflation pressure of the tire 2 and thanks to a groove in the rim containing it. The axially outer end 11 has a shoulder 16 forming a face substantially perpendicular to the axis of rotation X-X'.Said expander 1 comprises a seat on expander 14 which receives the bead 21 of the tire. The bead 21 is immobilized by being pressed axially on said seat 14 against said shoulder 16 of the axially outer end 11 of the expander, under the effect of the inflation pressure of the tire.

[0028] The axially inner end 10 of the extender comprises an inner reinforcing element 17 (preferably made in the form of a cable winding) connected to the outer reinforcing element 15 by a reinforcing ply made from reinforcing threads embedded in an elastomeric composition and forms with the reinforcing elements 15, 17 an internal structure of the extender. Other external elastomeric plies surround the internal structure of the extender.

[0029] The assembly is mounted by arranging the extender 1 on the rim 5 and then mounting the tire 2 on the extender 1. Once mounted, the bead of the tire imposes a circumferential contraction of the extender 1.

[0030] The axially outer end 11 of the extender 1 of the invention comprises a visible face 20 made so as to reveal the axially outer faces 31 of several inserts 30 fixed to the extender 1 and distributed over the circumference of said visible face 20. In the variant illustrated in figure 1, the inserts 30 protrude relative to the flat surface of the visible face 20. In other variants, the axially outermost faces of the inserts 30 are located at the level of the visible surface 20. In other variants, the axially outermost faces of the inserts are located axially further inward relative to the level of the visible face 20, but these inserts are visible thanks to cutouts made in the surface of the visible face 20 allowing all or part of the axially outer faces of the inserts mounted fixed on the extender to be seen.

[0031] There figure 2 illustrates an extender 1 of the invention whose axially outer end 11 comprises a visible face 20 whose circumference is provided with several inserts 30 uniformly distributed over its circumference.

[0032] In a first embodiment, the inserts 30 are fixed by gluing in housings 40 obtained during the cooking of the expander. The housings 40 have a cross section in the shape of an arc of a circle ( Fig. 3 ) or dovetail ( Fig. 4 ). The 40 accommodations Figures 3 and 4 have a generally elongated shape and are preferably inclined, they make an angle of between 30 and 60° with the circumferential direction of the extender. The inserts 30 have a generally elongated shape and are fixed permanently or in a non-removable manner using a suitable adhesive. For example, when the needles are metallic, a cyanolite type adhesive is used to ensure their good fixing by gluing in housings made of an elastomeric material.

[0033] There figure 10illustrates by an enlarged view an insert 30 in a housing 40 provided with several notches 42 made in its walls. The notches 42 receive glue and make it possible to control the thickness of the layer of glue applied for better retention of the attachment of the insert 30.

[0034] In a second embodiment, the inserts 30 are secured to the extender by being molded in the same mold and at the same time as the latter. In this embodiment, as better seen in the Fig. 6 , the inserts 30 are connected at their base by two hoops 35, 36 of metal wire and form a unitary assembly 37. The assembly 37 is placed at the bottom of a mold provided for the cooking of the expander 1 before cooking. The blank expander is added to the mold which is then closed and heated to carry out the cooking of the entire expander and the inserts. After cooking, the expander 1 is removed from the mold and is of the type better visible at Figure 5. It is thus noted that only the axially upper faces 31 of the inserts 30 are visible, the rest of the assembly 37 being embedded in the mass based on elastomeric material of the extender 1.

[0035] THE figures 7 to 9 illustrate different examples of extender design 1 of the invention. The figure 7 illustrates a variant in which the inserts 30 have a spherical shape and are fixed by gluing in housings in the shape of a corresponding spherical cap. The figure 8 illustrates another variant of extender comprising two rows of spherical-shaped inserts 30. The figure 9 illustrates a variant in which the inserts 30 have a cylindrical needle shape with rounded edges. In another variant (not illustrated in the figures) the heads of the inserts are plates, for example of triangular shape.

[0036] For example, an extender 1 allowing the mounting of a 20" tire on a rim may comprise a number of 200 to 300 elongated inserts, as illustrated in figure 9 , the inserts having a length between 9 mm and 15 mm and a width between 2 mm and 4 mm.

[0037] The inserts 30 are preferably metallic, for example made of stainless steel or anodized aluminum or steel coated with paint and varnish. In one variant, they are made of a metallized plastic material. In another variant, they are made of a colored plastic material. In yet another variant, the inserts have different colors, preferably all the colors of a rainbow so that, when the wheel rotates, the inserts produce the impression of a white color.

[0038] It was found during laboratory tests that a rolling assembly comprising an extender according to the invention connecting a 20" wheel to its rim can withstand without damage an impact against a 90 mm curb at a speed of 55 km / h and this without any impact on the appearance of the extender or on the hold of the inserts. The same impact suffered by a rolling assembly according to document WO201807751 of the technique leads to a detachment of the trim ring at around 15 km / h.

[0039] The invention is not limited to the embodiments described above. Thus, it is possible to envisage various other shapes of inserts (cube-shaped, parallelepiped-shaped, pyramid-shaped, or other three-dimensional solid) fixed by gluing to the extender or by molding with it.

[0040] In fact, it will be possible to combine the different embodiments described above, in particular to combine the means of fixing the inserts of the figures 5 to 6 to those of figures 7 to 9.

[0041] Furthermore, at least one of the inserts of the extender of the invention may be a part offering certain functionalities, such as an acceleration sensor or an identification or anti-theft chip, or even energy storage or other, in which case it will be fixed by gluing to the extender.

Claims

1. Adapter (1) for a rolling assembly of rotation axis X-X' comprising a tyre (2), having two beads (21) and a rim (5), the adapter (1) being intended to provide the join between one of the beads (21) and the rim (5), said adapter (1) comprising an axially inner end (10), an axially outer end (11) and a body (12) oriented principally axially and arranged between said axially outer end (11) and said axially inner end (10), such that, when mounted within the assembly, said axially inner end (10) is intended to be immobilized on said rim by means of an inner reinforcing element (17), said axially outer end comprising an outer reinforcing element (15) is intended to receive a bead (21) of a tyre (2), characterized in that the axially outer end (11) includes a visible face (20) designed to reveal the axially outer faces (31) of several inserts (30) fastened to the extender (1) and distributed about the circumference of said visible face (20).

2. Adapter according to Claim 1, wherein said inserts (30) are made of metal.

3. Adapter according to one of Claims 1 or 2, characterized in that said visible surface (20) is the axially outermost face of said axially outer end (11) and in that the inserts (30) protrude from said face.

4. Adapter according to one of Claims 1 to 3, characterized in that said inserts (30) are made in the form of several individual elements connected to each other at their base.

5. Adapter according to one of Claims 1 to 3, characterized in that said inserts (30) are separate individual elements.

6. Adapter according to one of the preceding claims, characterized in that said inserts (30) have an elongated shape, their length being at most equal to the width of said visible face (20) of the axially outer end of the adapter.

7. Adapter according to Claim 6, characterized in that said inserts (30) are uniformly distributed about the circumference of said visible face (20) of the adapter.

8. Adapter according to one of Claims 5 to 7, characterized in that said inserts are fastened in seats (40) each comprising several notches made in the walls thereof.

9. Adapter according to one of the preceding claims, characterized in that said inserts (30) are arranged in a radial direction or in a direction which forms a constant acute angle with the radial direction of the adapter.

10. Method of manufacturing an adapter according to one of the preceding claims, characterized in that it comprises a step of moulding said inserts (30) at the same time and in the same mould as the adapter (1).

11. Method of manufacturing an adapter according to one of Claims 1 to 3 and 5 to 9, characterized in that it comprises a step of glueing said inserts (30) in seats provided for this purpose in the axially outer end of the adapter.

12. Rolling assembly of rotation axis X-X' comprising a tyre (2), having two beads (21), a rim (5) and an adapter (1) according to one of Claims 1 to 9 intended to provide the join between one of the beads (21) and the rim (5).