Apparatus for manufacturing electric wire having wire-enamel-type insulation
AssigneeMaillefer S.A.
InventorEberhard Kertscher
Life of this patent
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Abstract
An apparatus for manufacturing insulated electric wire of the enamelled-wire type wherein an insulating sheath adhering to the wire is formed by extrusion of selected thermoplastics which are heated to a temperature above their melting-point, then pressed onto the wire while in a fluid state. The extrusion apparatus includes a gauging die with a compressing cone having an aperture angle of from 2.degree. to 20.degree., preferably 7.degree..
Claims9
Apparatus for manufacturing insulated electric wire of the enamelled-wire type with an insulating sheath of plastic material, comprising a screw extruder and an extrusion head connected at the downstream end of said screw-extruder, said extrusion head comprising at least one extrusion unit formed of a die-holder with a gauging die and a guiding die coaxially held therein, said gauging die having:
- a cylindrical bore portion at its downstream end;
- a frustoconical bore joining said cylindrical bore portion at the upstream side thereof;
- and a frustoconical entry portion of an aperture angle greater than said frustoconical bore, joining said frustoconical bore at the upstream end thereof, said guiding die having a central passageway matching said wire in diameter and a downstream face of frustoconical shape facing said entry portion, said downstream face and said entry portion determining therebetween an annular distribution chamber of frustoconical shape arranged in such a manner that said plastic material gradually accelerates therein, and said die holder containing holes therethrough for feeding the annular base of said distribution chamber with plastic material from said extruder.
Dependencies are inferred from the claim text.