Mold with sectors for tires, in particular tires for agricultural vehicles, and associated molding method

A mold for a tire comprising a tread and two side walls, the mold comprising:

• lower and upper portions which are intended for molding at least the side walls of the tire and movable at least axially relative to one another between a close-together molding position for molding the tire and a distanced position for extracting the tire from the mold;
• and
• a plurality of sectors which are in axial contact with the lower and upper portions in the close-together molding position and are intended to ensure molding of at least a central portion of the tread of the tire, the plurality of sectors being distributed in a circumferential direction and movable relative to the lower and upper portions,
• wherein the lower and upper portions are each provided with a support face in axial contact with a front face of each sector in the close-together molding position of the lower and upper portions, and with a tapered holding face extending the support face toward an inside and radially engaged against a complementary outer face of each sector in the close-together molding position, and
• wherein, for each sector, the mold further comprises coupling members, including a permanent coupling member for permanently coupling the sector to the upper portion and fixed to the upper portion, and a temporary coupling member for temporarily coupling the sector to the lower portion and fixed to the lower portion, the coupling members being distinct from the tapered holding faces of the lower and upper portions and configured so as to obtain:
• during an axial distancing movement, providing an axial displacement, of the lower and upper portions from the close-together molding position, a disengagement of the sector from the support faces and from the tapered holding faces of the lower and upper portions, and after the disengagement a radial displacement of the sector toward an outside followed by an angular pivoting of the sector toward the outside under an effect of a weight of the sector, around an axis perpendicular to directions of axial and radial displacement, and
• during an axial approaching movement of the lower and upper portions from the distanced position for extraction from the mold, reverse movements of the sector.

A mold for a tire comprising a tread and two side walls, the mold comprising:

• lower and upper portions which are intended for molding at least the side walls of the tire and movable at least axially relative to one another between a close-together molding position for molding the tire and a distanced position for extracting the tire from the mold;
• and
• a plurality of sectors which are in axial contact with the lower and upper portions in the close-together molding position and are intended to ensure molding of at least a central portion of the tread of the tire, the plurality of sectors being distributed in a circumferential direction and movable relative to the lower and upper portions,
• wherein each sector comprises a fixing flange protruding radially towards an outside relative to the lower and upper portions, and guide fingers axially arranged on either side of the fixing flange,
• wherein, for each sector, the mold further comprises coupling members, including a permanent coupling member for permanently coupling the sector to the upper portion and fixed to the upper portion, and a temporary coupling member for temporarily coupling the sector to the lower portion and fixed to the lower portion, the coupling members being configured so as to obtain:
• during an axial distancing movement, providing an axial displacement, of the lower and upper portions from the close-together molding position, a radial displacement of the sector toward the outside followed by an angular pivoting of the sector toward the outside under an effect of a weight of the sector, around a pivot axis perpendicular to directions of axial and radial displacement, and
• during an axial approaching movement of the lower and upper portions from the distanced position for extraction from the mold, reverse movements of the sector,
• wherein each of the permanent and temporary coupling members associated with each sector comprises a guide groove, inside which one of the guide fingers of the sector is slidingly engaged and which is provided with at least one oblique portion for ensuring radial displacements of the sector, and
• wherein a finger of the sector engaged in the guide groove of the permanent coupling member forms the pivot axis of the sector.