Tire Comprising a Sidewall Insert

Abstract

A tire (1) having at least one sidewall (3), intended to interact with a sidewall insert (9) by way of an anchor (6), and aims to personalize the design of the sidewall. The anchor (6), has a recess (7) formed in an axially outer sidewall layer (30), with a protuberance (8), which is raised in relation to the recess bottom (71) and extends from the recess bottom (71) to the vicinity of the axially outer sidewall face (31), and the protuberance (8) is constituted by a stepped arrangement of a first narrow portion (81) having a minimum width Lpmin and a second wide portion (82) having a maximum width Lpmax, such that the difference LpmaxLpmin is at least equal to 1 mm and at most equal to 4 mm.

Claims

1. A tire for a lightweight vehicle, which tire is intended to be mounted on a rim and is able to be equipped with at least one sidewall insert, said tire having a nominal section of height H and comprising: two sidewalls that connect a crown respectively to two beads, each of which is intended to come into contact with the rim, at least one sidewall comprising an anchoring means intended to interact with at least one sidewall insert, the anchoring means extending circumferentially, in a circumferential direction (XX) of the tire, and comprising a recess formed in an axially outer sidewall layer comprising at least one rubber material and extending from an axially outer sidewall face axially towards the inside of the sidewall, the recess being delimited axially towards the inside by a recess bottom and radially by two recess walls, the recess having, in any meridian plane (YZ) containing the axis of rotation (YY) of the tire, a depth Pc, the maximum distance measured perpendicularly between the axially outer sidewall face and the recess bottom, which is at least equal to 2 mm, and a width Lc measured, at the axially outer sidewall face, between the two recess walls which is at most equal to 15% of the nominal section height H of the tire, wherein the anchoring means comprises a protuberance, which is raised in relation to the recess bottom and extends from the recess bottom to the vicinity of the axially outer sidewall face (31), and wherein the protuberance is constituted, in any meridian plane (YZ), by a stepped arrangement of a first narrow portion, extending axially towards the outside from the recess bottom and having a minimum width equal to a minimum protuberance width Lpmin, and a second wide portion, extending axially towards the outside from the first narrow portion and having a maximum width equal to a maximum protuberance width Lpmax, such that the difference LpmaxLpmin is at least equal to 1 mm and at most equal to 4 mm.

2. The tire according to claim 1, wherein the depth Pc of the recess is at least equal to 3 mm.

3. The tire according to claim 1, wherein the depth Pc of the recess (7) is at most equal to 7 mm.

4. The tire according to claim 1, the axially outer sidewall layer having a width W at the anchoring means, wherein the difference between the thickness W of the axially outer sidewall layer and the depth Pc of the recess is at least equal to 1 mm.

5. The tire according to claim 1, wherein the width Lc of the recess is at most equal to 10% of the nominal section height H of the tire.

6. The tire according to claim 1, wherein the width Lc of the recess is at most equal to 20 mm.

7. The tire according to claim 1, wherein the recess is formed in an axially outer sidewall layer made up of a single rubber material.

8. The tire according to claim 1, wherein the straight line (T), which is present in any meridian plane (YZ) and passes through two intersection points respectively of each recess wall with the axially outer sidewall face, forms an angle (A) at most equal to 25, with the radial direction (ZZ).

9. The tire according to claim 1, wherein the protuberance has, in any meridian plane (YZ), a height Hp at least equal to the depth Pc of the recess less 2 mm.

10. The tire according to claim 1, wherein the protuberance has, in any meridian plane (YZ), a height Hp at most equal to the depth Pc of the recess plus 2 mm.

11. The tire according to claim 1, the sidewall comprising, on its axially outer sidewall face and in the radially outer vicinity of a bead, a protective ridge having an edge corner, and the anchoring means having a circumferential mean line, wherein the circumferential mean line of the anchoring means is positioned, in any meridian plane (YZ), at a radial distance d1 at least equal to 4 mm, radially on the outside of the edge corner of the protective ridge.

12. The tire according to claim 11, wherein the circumferential mean line of the anchoring means is positioned, in any meridian plane (YZ), at a radial distance d2 at least equal to 10% of the nominal section height H of the tire, radially on the inside of an axial straight line (D) passing through the halfway point H/2 of the nominal section height of the tire.

13. A sidewall insert intended to interact with an anchoring means of a tire according to claim 1, by engaging in the recess of the anchoring means and by attaching over the protuberance of the anchoring means.

14. The sidewall insert according to claim 13, the anchoring means comprising a protuberance having an outer meridian profile (P), the sidewall insert having an inner meridian profile (P) parallel to the outer meridian profile (P) of the protuberance, such that the inner meridian profile (P) of the sidewall insert has a minimum insert width Limin, at the minimum protuberance width Lpmin, and a maximum insert width Limax, at the maximum protuberance width Lpmax.

15. The sidewall insert according to claim 13, wherein the difference Lpmaxleast equal to 1.5 mm.

16. The sidewall insert according to claim 13, wherein the difference LpmaxLimin between the maximum protuberance width Lpmax and the minimum insert width Limin is at most equal to 2*E, E being the distance between the straight line (G) passing through the section of minimum insert width Limin and the axially outer bearing face of the insert that bears against the protuberance.

17. The sidewall insert according to claim 13, having a circumferential mean line having a mean diameter D2, before the sidewall insert is anchored to the tire, at most equal to a mean diameter D1 of a circumferential mean line of the anchoring means.

18. The sidewall insert according to claim 13, comprising at least one polymeric material.

19. The sidewall insert according to claim 13, which is made of a material having a tensile elastic modulus at 10% elongation M2 and is intended to interact with an anchoring means made of a rubber material having a tensile elastic modulus at 10% elongation M1, wherein M2 is at least equal to 0.4*M1.

20. The sidewall insert according to claim 13, which is made of a material having a tensile elastic modulus at 10% elongation M2 and is intended to interact with an anchoring means made of a rubber material having a tensile elastic modulus at 10% elongation M1, wherein M2 is at most equal to 5*M1.

21. The sidewall insert according to claim 13, having a colouration and/or a texture different from those of the sidewall comprising the anchoring means.

22. An assembly made up of a tire according to claim 1 and at least one sidewall insert intended to interact with an anchoring means of the tire by engaging in the recess of the anchoring means and by attaching over the protuberance of the anchoring means.

Description

[0064] The features of the invention are illustrated by the schematic FIGS. 1 to 5, which are not drawn to scale:

[0065] FIG. 1: Meridian half-section through a tire according to the invention, mounted on its rim,

[0066] FIG. 2: Meridian section through an anchoring means according to the invention,

[0067] FIG. 3: Meridian half-section through a tire according to the invention, mounted on its rim and equipped with a sidewall insert,

[0068] FIG. 4: Meridian section through an anchoring means according to the invention, in combination with a sidewall insert.

[0069] FIG. 1 is a meridian half-section through a tire 1 according to the invention, mounted on its rim 2. The tire 1 for a lightweight vehicle is mounted on a rim 2 and is able to be equipped with at least one sidewall insert 9 (not shown). The tire 1 has a nominal section of height H within the meaning of the ETRTO (European Tire and Rim Technical Organisation) standard and comprises two sidewalls 3 that connect a crown 4 respectively to two beads 5, each of which is intended to come into contact with the rim 2. The sidewall 3 shown comprises an anchoring means 6, intended to interact with a sidewall insert 9 (not shown). The anchoring means 6 extends circumferentially, in a circumferential direction XX of the tire, and comprises a recess 7 formed in an axially outer sidewall layer 30 comprising at least one rubber material and extending from an axially outer sidewall face 31 axially towards the inside of the sidewall 3. According to the invention, the anchoring means 6 comprises a protuberance 8, which is raised in relation to the recess bottom and extends from the recess bottom to the vicinity of the axially outer sidewall face 31, and the protuberance 8 is constituted, in any meridian plane YZ, by a stepped arrangement of a first narrow portion, extending axially towards the outside from the recess bottom and having a minimum width equal to the minimum protuberance width Lpmin (not referenced), and a second wide portion, extending axially towards the outside from the first narrow portion and having a maximum width equal to the maximum protuberance width Lpmax. In the particular embodiment shown in FIG. 1, on its axially outer sidewall face 31 and in the radially outer vicinity of the bead 5, the sidewall 3 comprises a protective ridge 32 having an edge corner 321. The edge corner 321 of the protective ridge 32 is the vertex of the substantially triangular section of the protective ridge, which is not located on the axially outer sidewall face 31. With the anchoring means 6 having a circumferential mean line 61, the circumferential mean line 61 of the anchoring means 6 is positioned, in the meridian plane YZ, at a radial distance d1 at least equal to 4 mm, radially on the outside of the edge corner 321 of the protective ridge 32. Moreover, the circumferential mean line 61 of the anchoring means 6 is positioned, in the meridian plane YZ, at a radial distance d2 at least equal to 10% of the nominal section height H of the tire 1, radially on the inside of an axial straight line D passing through the halfway point H/2 of the nominal section height of the tire 1.

[0070] FIG. 2 is a meridian section through an anchoring means 6 according to the invention. This is a detailed view of FIG. 1. The anchoring means 6 comprises a recess 7 and a protuberance 8. The recess 7 is delimited axially towards the inside by a recess bottom 71 and radially by two recess walls 72. The recess 7 has, in the meridian plane YZ containing the axis of rotation YY of the tire, a depth Pc, the maximum distance measured perpendicularly between the axially outer sidewall face 31 and the recess bottom 71, and a width Lc measured, at the axially outer sidewall face 31, between the two recess walls 72. The depth Pc of the recess 7 is at least equal to 2 mm and at most equal to 7 mm. The width Lc of the recess 7 is at most equal to 15%, preferably at most equal to 10% of the nominal section height H of the tire 1. With the axially outer sidewall layer 30 having a thickness W at the anchoring means 6, the difference between the thickness W of the axially outer sidewall layer 30 and the depth Pc of the recess 7 is at least equal to 1 mm. Moreover, the straight line T, which is present in the meridian plane YZ and passes through two intersection points 721, 722 respectively of each recess wall 72 with the axially outer sidewall face 31, forms an angle A at most equal to 25 with the radial direction ZZ. Lastly, the protuberance 8 is constituted, in any meridian plane YZ, by a stepped arrangement of a first narrow portion 81, extending axially towards the outside from the recess bottom 71 and having a minimum width equal to the minimum protuberance width Lpmin, and a second wide portion 82, extending axially towards the outside from the first narrow portion 81 and having a maximum width equal to the maximum protuberance width Lpmax.

[0071] FIG. 3 is a meridian half-section through a tire according to the invention, mounted on its rim and equipped with a sidewall insert. It combines the tire of FIG. 1 with a sidewall insert 9.

[0072] FIG. 4 is a meridian section through an anchoring means 6 according to the invention, as shown in FIG. 2, in combination with a sidewall insert 9. This is a detailed view of FIG. 4. The anchoring means 6, comprising a protuberance 8, has an outer meridian profile P. The sidewall insert 9 has an inner meridian profile P parallel to the outer meridian profile P of the protuberance 8. The inner meridian profile P of the sidewall insert 9 has a minimum insert width Limin, at the minimum protuberance width Lpmin, and a maximum insert width Limax, at the maximum protuberance width Lpmax. Moreover, according to the preferred variant shown, the difference LpmaxLimin between the maximum protuberance width Lpmax and the minimum insert width Limin is at least equal to 1.5 mm and at most equal to 2*E, E being the distance between the straight line G passing through the section of minimum insert width Limin and the axially outer bearing face 91 of the insert 9 that bears against the protuberance 8.

[0073] The inventors have more particularly examined this invention for a tire of size 245/45 R 18 100 W XL, which is intended to be inflated to a recommended pressure equal to 2.9 bar and to bear a recommended load equal to 800 kg.

[0074] The characteristics of the example examined by the inventors are presented in Table 1 below:

TABLE-US-00001 TABLE 1 Characteristics Characteristic values Comments Nominal section H of the tire 110 mm Radial distance d1 from the 8.4 mm At least equal to 4 anchoring means to the mm protective ridge Radial distance d2 from the 20 mm At least equal to 10% anchoring means to the of H = 11 mm halfway point of the nominal section height Depth Pc of the recess 3.9 mm At least equal to 2 mm and at most equal to 7 mm Width Lc of the recess 9.1 mm At most equal to 15% of H = 16.5 mm Height Hp of the protuberance 2.9 mm At least equal to Pc-2 mm = 1.9 mm and at most equal to Pc + 2 mm = 5.9 mm Minimum width Lpmin of the 4.4 mm protuberance Maximum width Lpmax of 5.4 mm Lpmax-Lpmin = 1 the protuberance mm, thus at least equal to 1 mm and at most equal to 4 mm Thickness W of the axially 7.5 mm W-Pc = 3.6 mm, thus outer sidewall layer at least equal to 2 mm Minimum width Limin of the 3.9 mm Lpmin-Limin = 0.5 sidewall insert mm (locking in the min. section) Maximum width Limax of the 5.2 mm Lpmax-Limax = 0.2 sidewall insert mm (locking in the max. section) Distance E between the 2.25 mm straight line G passing through the section of minimum width of the insert and the axially outer bearing face of the insert Difference Lpmax-Limin 1.5 mm 1.5 mm <= Lpmax- Limin <= 2*E = 4.5 mm

[0075] The inventors were able to note facilitated mounting and more effective attachment for a sidewall insert with which a sidewall of the tire according to the invention is equipped.