Manufacture of a strip by extrusion of a tube then flattening the tube
A process and apparatus for laying a strip for the manufacture of a tire by extruding uncured rubber through a die to form a rubber tube on a rotary support and flattening the tubular form to form a band which is adhered to a receiving surface on the rotary support.
1. A machine for laying a component comprising uncured rubber for the manufacture of a tire, said machine winding a band on a rotary support, said machine comprising:
an extruder equipped with a die imparting a tubular form to the section of extruded uncured rubber,
a rotary support of revolution, serving as a reference for the manufacture of the tire,
a manipulating robot which imparts all the desired relative positions between said support of revolution and said die, and
at least one roller downstream of said die cooperating with the rotary support to flatten the tubular form on the rotary support.
2. The machine according to claim 1 , wherein said extruder comprises a piston.
3. The machine according to claim 1 , wherein said die comprises a nozzle having an extrusion orifice and an ovoid fastened to said nozzle and partially blocking off the extrusion orifice so as to provide an air gap between the nozzle and the ovoid, the air gap ending in an extrusion section.
4. The machine according to claim 3 , wherein the ovoid is in a position within the nozzle which is adjustable between a centered position and eccentric positions.
5. The machine according to claim 3 , wherein the air gap has a minimum size upstream of the extrusion orifice.
6. The machine according to claim 3 , further comprising a pipe which passes through the ovoid and opens into the extrusion orifice for introducing a material into said tubular form.
7. The machine according to claim 3 , wherein the nozzle and the ovoid comprise a frustoconical surface and wherein the ovoid is in a position within the nozzle which is adjustable in a direction parallel to flow of uncured rubber in the air gap.