Apparatus for manufacturing electric wire having wire-enamel-type insulation
First Claim
1. 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.
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Accused Products
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° to 20°, preferably 7°.
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Citations
9 Claims
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1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a cylindrical bore portion at its downstream end;
Specification