# US 4,393,809 A · Apparatus for manufacturing magnet wire > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,393,809 A - Document ID: US4393809A - Status: Granted - Kind: A - Application number: 05/931,314 - Filed: 1978-08-07 - Granted: 1983-07-19 - Earliest claimed: 1978-08-07 - Assignees: Phelps Dodge Industries, Inc. - Inventors: George D. Hilker - Web page: https://patentgrep.com/patent/US4393809A ## CPC - H01B 13/16: by passing through or dipping in a liquid bath; by spraying - B05C 11/021: {Apparatus for spreading or distributing liquids or other fluent materials already applied to the surface of an elongated body, e.g. a wire, a tube} - H01B 13/065: {Insulating conductors with lacquers or enamels} - B05C 11/1042: {provided with means for heating or cooling the liquid or other fluent material in the supplying means upstream of the applying apparatus} - Y10S 118/18: Wire and cord die - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - B05C: APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (spraying apparatus, atomising apparatus, nozzles B05B; plant for applying liquids or other fluent materials to objects by electrostatic spraying B05B5/08) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A novel method and apparatus for manufacturing magnet wire in a continuous process by which coatings of a flowable resin material may be applied concentrically to a moving elongated filament in thicknesses of about 16 mils or less. The filament can be a bare copper or aluminum conductor having round or rectangular configuration or an insulated conductor upon which a top or an intermediate coat of material is desirably applied. Coatings of one and two mils also can be applied by the method of the invention. By the method and apparatus of the invention, magnet wire can be manufactured by continuously drawing the wire to size, annealing the wire, if necessary, insulating the wire with one or more coats of flowable resin material, curing the resin material, if necessary, hardening the resin material, and spooling the wire for shipment, without interruption at speeds limited only by the filament pay-off and take-up devices used. The apparatus of the invention utilizes the flowable resin material to center the filament in a die, the size of the die controls the thickness of the coat to be applied. In the apparatus of the invention, only the resin material being applied to the filament is in contact with the filament. Thus, the mechanical wear normally associated with centering dies used in extrusion process and like devices is completely eliminated. Further, the apparatus and method of the invention can be used to apply coats several times thinner than is possible with conventional extrusion apparatus and of materials different than those conventionally extruded onto filaments. In specific embodiments using heat softenable materials or melts, curing is no longer required; and thus, the need for curing, catalytic burners and the like as well as all concerns regarding atmospheric pollution are eliminated. The coated filaments and magnet wire made by the apparatus and in accordance with the method of the invention have coatings which are surprisingly concentric and continuous when compared to magnet wire made by conventional methods and apparatus. ## Claims ### Claim 1 An apparatus for the manufacture of coated filaments such as magnet wire comprising a die, a bare filament pay-out device, a coated filament take-up device, said die being located between said pay-out and take-up devices, said die having a throat portion, an entrance opening larger than said throat portion interconnected by a converging interior wall, thereby defining a cavity between said throat portion and said opening, said die being positioned to receive a filament trained between said pay-out and take-up devices in said opening and throat portion, said die being fixed in position, a reservoir of flowable but hardenable material, a flowable material applicator connected to said reservoir means, said applicator applying said material to said filament just prior to said filament entering said die and in excess of that required to coat said filament to a desired thickness in a single pass, whereby said excess collects in said die cavity, and means including said material in said die cavity for centering said filament in said throat portion. ### Claim 2 (depends on 1) The apparatus of claim 1 including a filament heater positioned on said filament between said pay-out device and said die. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein said filament heater heats said filament from about ambient temperature to about the decomposition temperature of said material at a position just prior to the application of said material to said filament by said applicator. ### Claim 4 (depends on 2) The apparatus of claim 2 wherein said filament is of the group consisting of bare copper and bare aluminum conductors, and said filament heater includes a filament annealer. ### Claim 5 (depends on 4) The apparatus of claim 4 further comprising means for drawing a conductor into a conductor of smaller size, said drawing means being positioned between said pay-out device and said filament heater. ### Claim 6 (depends on 1) The apparatus of claim 1 including a filament heater, a die heater, and a reservoir material heater. ### Claim 7 (depends on 6) The apparatus of claim 6 further comprising means including said filament and die and reservoir heaters for controlling the viscosity of said material in said die cavity. ### Claim 8 (depends on 5) The apparatus of claim 5 further comprising a take-up device driver, and a pay-out device brake. ### Claim 9 (depends on 8) The apparatus of claim 8 including means for hardening said material on said filament between said die and said take-up device. ### Claim 10 (depends on 9) The apparatus of claim 9 wherein said die, applicator, and hardening means comprises a filament coating station, and wherein said apparatus includes a plurality of said coating stations in a spaced-apart relationship to each other and said take-up and pay-out devices. ### Claim 11 (depends on 1) The apparatus of claim 1 including a second die located between said pay-out and take-up devices, said second die having a throat portion, an entrance opening larger than said throat portion interconnected by a converging interior wall, thereby defining a cavity between said throat portion and said opening, said second die being positioned to receive a filament trained between said pay-out and take-up devices in said opening and throat portion. ### Claim 12 (depends on 1) The apparatus of claim 1 wherein said applicator includes a metering device, said device applying a measured amount of material on said filament. ### Claim 13 (depends on 1) The apparatus of claim 1 wherein said throat portion is tapered from said interior wall in the direction of filament travel. ### Claim 14 (depends on 13) The apparatus of claim 13 wherein the taper of said tapered throat portion is from about 1 to about 2 degrees. ### Claim 15 (depends on 14) The apparatus of claim 14 wherein said converging interior wall defines an angle with the axis of said die of about 5.degree. to about 40.degree..