Extended mobility tire with undulating sidewalls

• US 20050263230A1
• Filed: 05/18/2005
• Published: 12/01/2005
• Est. Priority Date: 11/18/2002
• Status: Active Grant

• Current Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Merino Lopez, Jose
• Granted Patent: US 7,281,557 B2
• Time in Patent Office: Days
• US Class Current: 152/454
• CPC Class Codes: B60C 9/09 combined with other carcass plies having cords extending diagonally from bead to bead, i.e. combined radial ply and bias angle ply
• CPC Class Codes: Y10T 152/10864 Sidewall stiffening or reinforcing means other than main carcass plies or foldups thereof about beads

Abstract

A tire comprising at least one carcass-type reinforcement structure anchored on each side in a bead, each bead being extended radially towards the outside by a sidewall comprising at least one substantially resilient circumferential cord disposed in the substantially median portion of said sidewalls, the carcass-type reinforcement structure extending circumferentially from the bead towards said sidewall and being arranged in such a way that, in the substantially median portion of the sidewall, the cords of said reinforcement structure exhibit different axial positions over the circumference, so as to form around the circumference a succession of substantially regular undulations forming an undulating circumferential profile. At rated pressure, the structural rigidity of the sidewalls is that of a standard tire, while at reduced pressure the sidewalls rigidify in such a way as to be able to bear the load.

Claims

1. A tire comprising at least one carcass-type reinforcement structure anchored on each side of the tire in a bead whose base is intended to be fitted on a rim seat, each bead being extended radially towards the outside by a sidewall, the sidewalls meeting up radially towards the outside with a tread and comprising at least one substantially resilient circumferential cord disposed in the substantially median portion of said sidewalls, the carcass-type reinforcement structure extending circumferentially from the bead towards said sidewall, a crown reinforcement, each of the beads comprising furthermore an anchoring zone allowing the reinforcement structure to be retained in each of said beads, said carcass-type reinforcement structure being arranged in such a way that, on the one hand, in the substantially median portion of the sidewall, the cords of said reinforcement structure exhibit different axial positions over the circumference, so as to form a sidewall zone with undulations comprising, around the circumference a succession of substantially regular undulations forming an undulating circumferential profile, and on the other hand, outside this zone, all cords of said carcass-type reinforcement structure exhibit a substantially identical axial position.

2. The tire of claim 1, in which said sidewall zone with undulations extends radially in the sidewall between the bead and the crown zone.

3. The tire of claim 1, in which in said sidewall zone with undulations, the various possible positions of the carcass-type reinforcement structure are located between a reinforcement structure path which is axially furthest to the inside and a reinforcement structure path which is axially furthest to the outside.

4. The tire of claim 1, in which said at least one circumferential cord is arranged on the circumference of the tire in different axial positions, so as to form around the circumference a succession of substantially regular undulations forming an undulating circumferential profile.

5. The tire of claim 4, in which the undulations formed by the circumferential cords on the one hand and the undulations formed by the reinforcement structure cords on the other hand are substantially congruent.

6. The tire of claim 1, in which the outer surface of said sidewall of the tire, in the zone where the reinforcement structure comprises said undulations, also exhibits an undulating circumferential profile, substantially congruent with said profile formed by said reinforcement structure.

7. The tire of claim 1, in which the radial position of a reinforcement cord, for a given circumferential position of the undulating circumferential profile, is substantially symmetrical in each sidewall relative to the median plane of said tire.

8. The tire of claim 1, in which the radial position of a reinforcement cord, for a given circumferential position of the undulating circumferential profile, is substantially opposing in each sidewall.