Apparatus for extruding a coating around an electric conductor

An apparatus (100) for the production of an electric conductor provided with at least a layer of coating plastic material;

• the apparatus (100) comprising:
• an extrusion head (10) including a guide through which passes an electric conductor (EC), said extrusion head (10) being configured for coating said electric conductor (EC) with at least the layer of coating plastic material;
• at least a main extruder (30) to which a first duct (21) for feeding a first coating plastic material to said extrusion head (10) is connectable;
• and
• at least an auxiliary extruder (40) to which a second duct (22) for feeding a second coating plastic material to said extrusion head (10) is connectable;
• said extrusion head (10) including a first plastic application point (PT1) and a second plastic application point (PT2), said second application point (PT2) being located downstream from said first application point (PT1), and both said first and said second application points (PT1 and PT2) being configured to apply coating plastic material to said electric conductor (EC);
• a device (20) being interposed between said extruders (30, 40) and said extrusion head (10) for a selection and a diversion of flows of coating plastic material;
• and
• at least a plastic material exhaust duct (24) for exhausting the first or second coating material from the device;
• the apparatus (100) being characterized in that said device (20) for the selection and the diversion of the flows is provided with:
• said first duct (21);
• said second duct (22);
• and said at least a plastic material exhaust duct (24);
• at least one means for excluding flow from said auxiliary extruder (40) to said second duct (22);
• at least a bypass duct (23) connected between said first duct (21) and said second duct (22), said bypass duct (23) being in selective flow communication with said first duct (21) and said second duct (22);
• a first flow-regulating means (VL1) arranged in an intersection point between said first duct (21) and said bypass duct (23);
• wherein said first flow-regulating means (VL1) enables bypass duct (23) to be in selective flow communication with said first duct (21) and said second duct (22);
• and
• a second flow-regulating means (VL2) arranged in an intersection point between said bypass duct (23) and said second duct (22),
• in a first configuration, said second flow-regulating means (VL2) is operably connected to said bypass duct (23) and said second duct (22), and said first flow-regulating means (VL1) is operably connected to said first duct (21) and said second duct (22), and said bypass duct (23);
• said first duct (21) being further connected to said main extruder (30);
• and wherein said apparatus is configured, in said first configuration, to deposit two layers of said first plastic material on said electric conductor (EC), one layer via said first duct (21) and one layer via said second duct (22), each of said two layers originating from same main extruder (30) and being applied simultaneously at said first and said second application points (PT1 and PT2), respectively;
• and
• in a second configuration, said second flow-regulating means (VL2) is operably connected to said bypass duct (23) and said second duct (22), and said first duct (21) is operably connected to said first flow-regulating means (VL1) being so configured and to said main extruder (30);
• said second duct (22) operably connected to said auxiliary extruder (40) and to said first duct (21), and wherein said apparatus is so configured, in said second configuration, to deposit one layer of said first coating plastic material on said electric conductor (EC) via said first duct (21) and one layer of said second coating plastic material on said electric conductor (EC) via said second duct (22), at said first and said second application points (PT1 and PT2) simultaneously, respectively.