DRUM FOR PRODUCING A TIRE, PROVIDED WITH RETRACTABLE SECTORS

• US 20160159023A1
• Filed: 07/23/2014
• Published: 06/09/2016
• Est. Priority Date: 08/01/2013
• Status: Active Grant

• Current Assignee: Compagnie générale des établissements Michelin
• Original Assignee: Compagnie générale des établissements Michelin, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: DELORME, Jean-Claude, LEBLANC, Dominique, DRUET, Michel
• Granted Patent: US 10,639,859 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29D 2030/2642 Adjusting the diameter of the drum, to match its circumference with the length of ply
• CPC Class Codes: B29D 2030/265 Radially expandable and contractable drum comprising a set of circumferentially arranged elastic, flexible elements, e.g. blades or laminas, with or without expandable annular sleeve or bladder
• CPC Class Codes: B29D 2030/2657 Radially expandable and contractable drum comprising a set of circumferentially arranged rigid elements, e.g. fingers or arms
• CPC Class Codes: B29D 30/12 Cores
• CPC Class Codes: B29D 30/24 Drums
• CPC Class Codes: B29D 30/242 for manufacturing substantially cylindrical tyre components without cores or beads, e.g. treads or belts
• CPC Class Codes: B29D 30/26 Accessories or details, e.g. membranes, transfer rings

Abstract

A drum for building a green tire casing having:

• • sectors that form a circumferential face of the drum, and
  • at least one cam for controlling a radial movement of the sectors with respect to a rotation axis of the drum.

The cam has two main faces and is designed such that a monotonous movement of the cam first of all causes the radial movement of some of the sectors by virtue of ramps situated on its first face without modifying a radial position of the other sectors, and then causes the radial movement of the other sectors by virtue of ramps situated on its second face, the movement of all of the sectors then being simultaneous.

Claims

1. A drum for building a green tire casing, comprising:

sectors that form a circumferential face of the drum, and

at least one cam for controlling a radial movement of the sectors with respect to a rotation axis of the drum,

the cam having at least two main faces and being designed such that a monotonous movement of the cam first of all causes the radial movement of some of the sectors by virtue of ramps situated on its first face without modifying a radial position of the other sectors, and then causes the radial movement of the other sectors by virtue of ramps situated on its second face, the movement of all of the sectors then being simultaneous.

2. The drum according to claim 1, wherein the sectors comprise sectors of a first type and sectors of a second type that are able to bear in the radial direction against the sectors of the first type, the cam being designed such that the sectors of the first type are moved by virtue of the ramps situated on the first face of the cam, the sectors of the second type being moved by virtue of the ramps situated on the second face of the cam.

3. The drum according to claim 2, wherein the sectors of the first type, after they have started to be moved by the cam, are received in depressions formed in the sectors of the second type.

4. The drum according to claim 1, wherein some of the ramps that are able to control the movement of some sectors have a portion in the form of an arc of a circle that is coaxial with a rotation axis of the cam.

5. The drum according to claim 1, wherein there are at least two of the cams.

6. The drum according to claim 1, wherein at least some of the sectors, and optionally all of the sectors, are mounted in a movable manner with respect to the support in a predetermined direction that is not radial with respect to the rotation axis and intersects the latter.

7. The drum according to claim 1, which comprises at least one set of equipment that is mounted in a sliding manner with respect to the support in the direction of the rotation axis and is connected to a plurality of the sectors.

8. The drum according to claim 1, wherein the sectors are contiguous in the circumferential direction.

9. The drum according to claim 1, wherein each sector has two flat main side faces that are designed to be located next to homologous faces of the adjacent sectors.

10. The drum according to claim 1, wherein at least some of the sectors, and optionally all of the sectors, have an outer face that has a contour with a trapezoidal overall shape.

11. A method for manufacturing a tire casing, wherein at least a part of a tread of a green form of the casing is assembled on a drum in accordance with claim 1.