Head for the co-extrusion of a complex rubber profiled element intended for the manufacture of a tire

A head for co-extrusion of a rubber profiled element intended for the manufacture of a tire, the head being configured to be mounted on a cylindrical-roller co-extrusion machine and the head comprising a lower wall of cylindrical profile extending radially lengthwise in a longitudinal direction about a central axis and extending rectilinearly widthwise in a transverse direction parallel to the central axis and perpendicular to the longitudinal direction, and the head comprising, from upstream to downstream of the lower wall of cylindrical profile, and in the longitudinal direction:

• (a) a first extrusion unit comprising a first extrusion duct opening into the lower wall of the head, the first extrusion duct being divided into sub-ducts in the transverse direction;
• (b) a first profiling blade defining a first shaping profile that is discontinuous in the transverse direction and situated radially beyond the lower wall of the head intermittently in the transverse direction;
• (c) a second extrusion unit comprising a second extrusion duct opening into the lower wall of the head, the second extrusion duct being divided into sub-ducts in the transverse direction;
• (d) a second profiling blade defining a second shaping profile situated radially beyond the lower wall of the head, the second shaping profile having no discontinuity in the transverse direction, the second profiling blade comprising at least one tooth extending radially inward but not reaching the lower wall of the head, each tooth being situated in a continuation of the longitudinal direction of a divider dividing the first extrusion duct into the sub-ducts in the transverse direction, creating a discontinuity in the first shaping profile of the first profiling blade in the transverse direction, and dividing the second extrusion duct into sub-ducts in the transverse direction, the second profiling blade incorporating at least one third extrusion duct opening into the lower wall of the head, and each outlet of the at least one third extrusion duct adjoining a tooth of the second profiling blade;
• and
• (e) a third profiling blade defining a final shaping profile situated radially beyond the lower wall of the head, the final shaping profile having no discontinuity in the transverse direction, the third profiling blade comprising at least one tooth extending radially inward but not reaching the lower wall of the head, and each tooth of the third profiling blade being situated in front of a tooth of the second profiling blade.