Abstract: An apparatus for manufacturing tread bands for vehicle tires includes at least one primary extrusion head, a preforming device, at least one auxiliary extrusion head, an auxiliary feeding channel, and an extrusion die. The preforming device includes a primary preforming channel operatively connected to the at least one primary extrusion head. The auxiliary feeding channel is operatively connected to the at least one auxiliary extrusion head. The auxiliary feeding channel connects to the primary preforming channel. A direction of the auxiliary feeding channel forms an angle between approximately 30° and 160° relative to a direction of the primary preforming channel. The extrusion die is connected to the preforming device and includes an extrusion outlet. The auxiliary feeding channel connects to the primary preforming channel substantially near the extrusion outlet.

Abstract: A tread band for vehicle tires is manufactured by conveying a primary elastomer material (4) through an extrusion path (11, 15) defined by a preforming channel (15) followed by an extrusion outlet (11) formed in a die (10). The preforming channel (15) is defined in a preforming device (9) comprising a drawer (12) operatively engaging a preformer (13). Formed in the drawer (12) is an auxiliary channel (17) the end length (17b) of which opens at right angles into the extrusion path (11, 15), close to the extrusion outlet (11). An auxiliary elastomer material (5) conveyed to the auxiliary feeding channel (17) is homogeneously distributed by a coating effect under the lower surface of the tread band (4a) crossing the extrusion outlet (11).

Abstract: A tread band for vehicle tires is manufactured by conveying a primary elastomer material (4) through an extrusion path (11, 15) defined by a preforming channel (15) followed by an extrusion outlet (11) formed in a die (10). The preforming channel (15) is defined in a preforming device (9) comprising a drawer (12) operatively engaging a preformer (13). Formed in the drawer (12) is an auxiliary channel (17) the end length (17b) of which opens at right angles into the extrusion path (11, 15), close to the extrusion outlet (11). An auxiliary elastomer material (5) conveyed to the auxiliary feeding channel (17) is homogeneously distributed by a coating effect under the lower surface of the tread band (4a) crossing the extrusion outlet (11).

Abstract: A tread band for vehicle tires is manufactured by conveying a primary elastomer material (4) through an extrusion path (11, 15) defined by a preforming channel (15) followed by an extrusion outlet (11) formed in a die (10). The preforming channel (15) is defined in a preforming device (9) comprising a drawer (12) operatively engaging a preformer (13). Formed in the drawer (12) is an auxiliary channel (17) the end length (17b) of which opens at right angles into the extrusion path (11, 15), close to the extrusion outlet (11). An auxiliary elastomer material (5) conveyed to the auxiliary feeding channel (17) is homogeneously distributed by a coating effect under the lower surface of the tread band (4a) crossing the extrusion outlet (11).