Tyre and method for making a tyre

Patent metadata

Field	Value
Publication number	US-10486475-B2
Application number	US-201515309549-A
Country	US
Kind code	B2
Filing date	May 5, 2015
Priority date	May 13, 2014
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A tyre including two toroidal bead portions housing an annular bead bundle ( 121 ); a toroidal body ply, folded, about a respective bead bundle forming a respective turn-up; two bead fillers, each in contact with a respective bead bundle and at least partly enclosed by a respective turn-up, and two elastomeric crack control members, one for each bead portion. Each crack control member extends at a body ply ending, and each crack control member is made by a couple of strips having a differentiated stiffness along their transversal section, with a lower stiffness at a first strip adjacent to the body ply ending and a higher stiffness at a second strip in contact with the respective bundle, so that the first lower stiffness strip defines a preferential propagation path for any tyre crack originating at the body ply folded ending.

First claim

The invention claimed is:

1. A tyre, comprising:
two toroidal bead portions, each of said two toroidal bead portions housing an annular bead bundle and having an external abrasion gum strip;
a toroidal body ply, which is folded, at each one of two transversal endings thereof, about a respective annular bead bundle forming a respective turn-up;
two bead fillers, one for each of said two toroidal bead portions, each of said two bead fillers being in contact with a respective bead bundle and being at least partly enclosed by a respective turn-up of said toroidal body ply,
wherein the tyre further comprises two crack control members, one for each of said two toroidal bead portions, wherein each crack control member of said two crack control members extends at a body ply ending axially externally to the respective turn-up, each crack control member having a differentiated stiffness along its transversal section, with a lower stiffness at a first portion adjacent to said body ply ending and a higher stiffness at a second portion remote from said body ply ending and adjacent a respective abrasion gum strip,
said first portion defines a preferential propagation path for any tyre crack originating at said body ply ending,
each of said crack control members is obtained as a part of, and/or is integral to, the respective bead filler,
each bead filler is made from a first, low-stiffness strip arranged in contact with said body ply and a second, high-stiffness strip having a higher stiffness than said first strip and arranged in contact with the respective bead bundle, wherein each of said first and second strip makes a respective first or second portion of said crack control member, and
each of said first and second strips is wound about the bead bundle according to a “U” or annular shape internally to the respective turn-up.

2. The tyre according to claim 1 , wherein one or more of the first strip or second strip of each bead filler have an outer end folded into a “U” about the respective body ply ending and out of the corresponding turn-up so as to enclose such body ply ending by forming a cap around it and making at least part of the respective crack control member.

3. The tyre according to claim 1 , wherein said first strip extends only at, or at a part of, a transverse terminal end of said body ply ending.

4. The tyre according to claim 1 , wherein said first portion of said crack control member has a stiffness of about M50≤2.5 MPa and ELB≥00% and/or said second portion of said crack control member has a stiffness M50 comprised in a range of about 2.0-11.0 MPa and ELB comprised in a range of about 80%-400%.

5. The tyre according to claim 1 , wherein, before vulcanization, said first portion of said crack control member has a thickness comprised in a range of about 0.2-1.5 mm and/or said second portion of said crack control member has a thickness comprised in a range of about 0.2-1.5 mm or 0.5-2.5 mm.

6. The tyre according to claim 1 , which is a tyre configured for a passenger vehicle.

7. The tyre according to claim 1 , wherein said two crack control members are made of elastomer.

8. The tyre according to claim 1 , wherein each of the first strip and the second strip are elastomeric material.

9. The tyre according to claim 1 , wherein both the first portion and the second portion of the each crack control member extend at the body ply ending axially externally to the respective turn-up.

Assignees

• Bridgestone Corp

Inventors

• Toscano Marco

Classifications

• B60C2015/0617

  comprising a cushion rubber other than the chafer or clinch rubber · CPC title

• B60C15/06 Primary

  Flipper strips, fillers, or chafing strips {and reinforcing layers for the construction of the bead} · CPC title

• B60C2015/0625

  provided at the terminal edge portion of a carcass or reinforcing layer · CPC title

• B29D2030/486

  Additional components for the tyre bead areas, e.g. cushioning elements, chafers, flippers · CPC title

• B29D30/48

  Bead-rings or bead-cores (from wire B21F37/00); Treatment thereof prior to building the tyre · CPC title