US3848341A - Method of drying coated wires - Google Patents

Abstract

Adjacent wires passing through drying oven after being coated with liquid enamel are run at different speeds to prevent wires from sticking together while curing.

Description

' United States Patent 191 Callan 118/68 X under Nov. 19, 1974 [54] METHOD OF DRYING COATED WIRES 1,485,254 2/1924 Dickie 34/154 UX 2,434,169 1 1948 L 341 4 [75] Inventor: Bernd Linder, Hendersonvrlle, N.C. 2,583,427 111952 I 2 9 2,994,624 8/196l. Lit et a1. 117/232 .[73] Asslgnee' General Electnc Comm"), 3,686,772 8/1972 Drummond 34/154 [22] Filed: May 22, 1972 ['21] Appl' 255792 Primary Examiner-Harry J. Gwinnell Attorney, Agent, or Firm-Sidney Greenberg [52] US. Cl .L-. 34/25, 34/52, 34/154, l17/119.6, 1l7/128.4, 117/232, 118/68, l18/DIG. 22 [51] Int. Cl. F26b 3/22, B44d l/42 [57] ABSTRACT [58] Field of Search 34/25, 52, 154; 117/119.6,

ll7/128.4, 232, 119.8; 118/68, DIG, 19, Adjacent wires passing through drying oven after DIG. l8, DIG. 20, D10. 22, 67, 405 being coated with liquid enamel are run at different speeds to prevent wires from sticking together while [56] References Cited curing.

UNITED STATES PATENTS 1 894,592 7/1908 4 Claims, 2 Drawing Figy res METHOD OF DRYING COATED WIRES The present invention relates to apparatus for applying coating compositions such as enamels, varnishes, lacquers and the like to elongated articles such as wire.

More particularly, the invention is concerned with an apparatus and method for handling multiple strands of coated wire passing through a drying oven.

It is an object of the invention to avoid the difficulties, including scrap waste and loss of productivity, attendant on the sticking together of adjacent coated wire strands passing through a drying oven.

It is a further object of the invention to provide for an increase in the number of coated wire strands which can be simultaneously treated in a drying oven while avoiding the above-described difficulties.

Specific objects of the invention are to provide an apparatus and a method for preventing coated wire strands from sticking together during the process for drying and curing the wire coating.

Other objects and advantages will become apparent from the following description and the appended claims.

With the above objects in view, the present invention in one of its aspects relates to wire coating apparatus comprising, in combination, coating means for applying hardenable liquid coating material on a plurality of wire strands, drying means for drying the coated strands for hardening the coating thereon, means for passing a plurality of coated wire strands adjacent one another through the drying means, and means forimparting relative motion between adjacent ones of the plurality of coated wire strands while passing through the drying means for preventing sticking of adjacent wire strands together.

The invention will be better understood from the following description taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a perspective, somewhat diagrammatic view, of a wire coating apparatus embodying the present invention; and v I FIG. 2 shows a modification of the apparatus shown in FIG. 1.

Referring now to the drawing, and particularly to FIG. 1, there is shown an apparatus for coating a plurality of wires with liquid insulating enamel and hardening by heat the thus applied coatings. For this purpose, there is provided a lower set of grooved guide sheaves l for respectively receiving a plurality ofwires 2, 3, 4 and 5 from pay-off supply reels (not'shown) and independently guiding the wires upwardly into vessel 6 containing a supply 7 of resinous viscous varnish (such as polyvinyl formal or polyester imide composition) to be applied to the wires. The wires are typically of copper or aluminum, but may be of various other types of metals or materials, and the enameling material may be of various other types of hardenable liquid coating composition. After emerging from wire coating vessel 6, the

' wires pass through wire coating dies 8 (shown in exaggerated scale) for removing excess liquid coating material therefrom, and the wires pass upwardly in closely adjacent arrangement through baking or drying oven .9 of any suitable or conventional type wherein the applied enamel coating is heat-hardened. Thereafter, the

wires pass around a set of independent upper guide.

sheaves 10 as they leave the top of oven 9..

In a typical embodiment of the invention,alternate wires 2 and 4 are thicker in diameter thanwires 3 and 5, shown in interrupted lines for clarity, and in accordance with the invention thethinner wires 3 and 5 are passed through oven 9 at a greater speed thanwires 2 and 4. As a result of thus providing for relative motion between the adjacent wire strands, the coated strands will not stick to one another during the process of drying in oven 9, even though the wire strands may come into contact with one another while passing through the oven.

For this purpose there is provided in the illustrated embodiment a set of guide sheaves 11 for transporting thethinner wires 3, 5 to a first driving roller 12 driven bymotor 13 and another set ofguide sheaves 15 for transporting thethicker wires 2, 4 to asecond driving roller 16 driven by motor 17 at a slower speed than roller 12 is driven bymotor 13, the wires being directed from the respective driving rollers to suitable take-up reels or other storage means (not shown). Since it requires less time to cure the coating on the thinner wires than on the thicker wires, inasmuch as there is less mass of coating on the thinner wires, effective drying and hardening of the coating on the latter wires are achieved despite their faster passage through the oven.

In a typical procedure, thethinner wires 3, 5 having, say, a 42 mil diameter may be run at a speed of feet/- minute, while thethicker wires 2, 4, which are typically of 50 mil diameter, may be run at 50 feet/minute.

While only four wire strands are shown for purposes of illustration, it will be understood that in practice a considerably larger number of wire strands will be run side by side with a similar arrangement of thinner wires interspaced between the thicker wires. It has been found that a spacing of as little as 7/16 inch or less between wire strands can be employed in practicing the invention while still obtaining satisfactory results.

It will also be understood that all the wires may be of the same size if desired, and the alternate wires can be run at slightly different speeds to obtain the benefits of the invention without adversely affecting the curing of the coatings thereon. It has been found, in fact, that in such a case, a speed difference of as little as 5 feet/minute is adequate to provide satisfactory results.

By virtue of the described invention, it is possible to arrange the coated wires closer together than heretofore without encountering the difficulty of the wires sticking together, and thus enable more effective use of existing oven capacity or permit the use of smaller size ovens. Moreover, the invention makes it possible to use taller wire towers with longer unsupported wire spans, which in prior wire coating apparatus increased the risk of adjacent wire strands coming into contact and sticking to one another. This advantage afforded by the invention is particularly significant in the use of aluminum wire, which usually cannot withstand the higher tension (such as is possible with copper wires) required to keep the wire strands separated in their passage through the drying oven, and which therefore must be run with greater slack. FIG. 2 shows a different embodiment of the driving means which may be used to run the alternate wires at different speeds without the use of separate drive rollers and motors. As shown, asingle drive roller 20 having largediameter sheave portions 20a and smalldiameter sheave portions 20b alternately formed thereon for receiving and driving all of is rotated bymotor 21.

While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the scope of the invention. Therefore, the appended claims are intended to cover all such equivalent variations as come within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. in a method of treating coated wires wherein a plurality of wire strands coated with heat hardenable coating material are passed closely adjacent one another in thesame direction through a drying oven for heat hardening the coating material, the improvement which comprises the step of imparting relative longitudinal motion between adjacent ones, of said plurality of coated wire strands during passage through said drying oven for preventing them from sticking together.

2. A method as defined in claim 1, wherein said step comprises moving adjacent ones of said coated wire strands at different speeds.

3. A method as defined inclaim 2, wherein alternate ones of said wire strands are thinner than the adjacent wire strands and are moved at a faster speed than said adjacent wire strands.

4. A method as defined in claim 1, wherein said step comprises moving alternate ones of said plurality of coated wire strands at a predetermined speed, while moving the remaining coated wire strands at a different predetermined speed.

Claims (4)

1. In a method of treating coated wires wherein a plurality of wire strands coated with heat hardenable coating material are passed closely adjacent one another in the same direction through a drying oven for heat hardening the coating material, the improvement which comprises the step of imparting relative longitudinal motion between adjacent ones of said plurality of coated wire strands during passage through said drying oven for preventing them from sticking together.

2. A method as defined in claim 1, wherein said step comprises moving adjacent ones of said coated wire strands at different speeds.

3. A method as defined in claim 2, wherein alternate ones of said wire strands are thinner than the adjacent wire strands and are moved at a faster speed than said adjacent wire strands.

4. A method as defined in claim 1, wherein said step comprises moving alternate ones of said plurality of coated wire strands at a predetermined speed, while moving the remaining coated wire strands at a different predetermined speed.

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