US 12,220,889 B2
Process for building tyres for vehicle wheels
Cesare Emanuele Amurri, Milan (IT); Christian De Col, Milan (IT); Marco Cantu′, Milan (IT); and Roger Basilico, Milan (IT)
Assigned to PIRELLI TYRE S.p.A., Milan (IT)
Appl. No. 17/595,697
Filed by Pirelli Tyre S.p.A., Milan (IT)
PCT Filed May 26, 2020, PCT No. PCT/IB2020/054964
§ 371(c)(1), (2) Date Nov. 22, 2021,
PCT Pub. No. WO2020/240407, PCT Pub. Date Dec. 3, 2020.
Claims priority of application No. 102019000007590 (IT), filed on May 30, 2019.
Prior Publication US 2022/0212430 A1, Jul. 7, 2022
Int. Cl. B29C 48/255 (2019.01); B29C 48/00 (2019.01); B29C 48/08 (2019.01); B29C 48/21 (2019.01); B29C 48/305 (2019.01); B29C 48/49 (2019.01); B29C 48/92 (2019.01); B29D 30/30 (2006.01); B29D 30/60 (2006.01); B29D 30/62 (2006.01); B29K 105/00 (2006.01); B29L 30/00 (2006.01)
CPC B29D 30/3021 (2013.01) [B29C 48/0021 (2019.02); B29C 48/08 (2019.02); B29C 48/21 (2019.02); B29C 48/2552 (2019.02); B29C 48/307 (2019.02); B29C 48/49 (2019.02); B29C 48/92 (2019.02); B29D 30/60 (2013.01); B29D 30/62 (2013.01); B29C 2948/926 (2019.02); B29C 2948/92647 (2019.02); B29C 2948/92876 (2019.02); B29D 2030/3078 (2013.01); B29K 2105/0023 (2013.01); B29K 2995/0005 (2013.01); B29L 2030/002 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for building tyres for vehicle wheels, wherein at least one elastomeric component of a tyre is made by applying at least one continuous elongated element according to a plurality of turns (C) around a forming drum rotating around a geometric rotation axis thereof;
wherein a method of making the continuous elongated element comprises:
extruding a first material, when a supply of the first material is activated, through an extrusion nozzle, to form an inner core of the continuous elongated element exiting from an outlet opening of the extrusion nozzle; and
during the extrusion, activating a supply of a second material different from the first material, for conveying the second material around the first material, at the extrusion nozzle and upstream of the outlet opening, to form a coating layer, wherein the coating layer surrounds the inner core;
wherein the second material is introduced into a second supply duct leading to an injection chamber arranged around a first supply duct axially converging into an outlet channel, the outlet channel longitudinally crossing the extrusion nozzle and leading to the outlet opening, the injection chamber flowing into the outlet channel through a radial intake slit extending along a closed line around the outlet channel, and
wherein the radial intake slit has a variable axial dimension along a peripheral development thereof.