US2575911A

US2575911A - Wire enameling die

Info

Publication number: US2575911A
Application number: US11591A
Authority: US
Inventors: Robert H Denham
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1948-02-27
Filing date: 1948-02-27
Publication date: 1951-11-20
Anticipated expiration: 1968-11-20

Description

NOV 20, 1951 R. H. DENHAM WIRE ENAMELING DE Filed Feb. 27. 1948 Inventor: y'Robert H. Denham,

His Att orneg.

Patented Nov.. 1951 2,515,911 wma ENAMELmo nm Robert H. Denham, Scotia, N. Y., assigner to General Electric (lompany,` a, corporation of New York Application February 21, lua'serm No. 11,591

11 claims. l

This invention relates to dies for coating wire, cable, textile threads and the like having a circular cross section. More especially it relates to dies having a non-circular die opening for uniformly coating round or circular wire with an enamel, varnish or lacquer and is of particular interest when used with coating materials applied in a highly viscous state.

Normally, round wires are coated using a die having a round hole of suiiicient clearance to pass the desired thickness of enamel or coating material. In order lto promotea more uniform deposition of material the round wire after passing through the viscous coating material is drawn vertically through the round die opening. However no adequate means has yet been devised to hold the wire in the center of this round opening to assure concentricity of the enamel film. Moreover, all such prior art dies whether of the type through which the wire passes vertically or of the type through which the wire passes horizontally are complicated in structure and therefore expensive to manufacture and maintain.

It is therefore an object of my invention to provide a die which will result in circular coated wire, cable and the like having a concentric coating or film" thereon.

It is another object of my invention to provide dies which will center round wire as it passes therethrough.

It is still a further object of my invention to provide supporting means for dies which permit full floating suspension of the dies supported thereon.

It is also an object of my invention to provide an improved construction and arrangement of dies which is simple in construction, cheap to manufacture and effective in operation.

In accordance with my invention, I provide, for circular wire, a non-circular die opening dened by a plurality of equally spaced wire cen-l tering points lying on the circumference of a circle having a diameter approximately equal to the diameter of the circular wire being coated which points are interconnected by surfaces lyscope of my invention will be pointed out in the appended claims. In the drawing Fig.. l illustrates an apparatus partially in section for enameling wire including a die embodying my invention; Fig. 2 is an enlarged side or elevation view of the die' of Figure 1 including the supporting means therefor; Fig. 3 is a plan view of the die and support of Fig. 2; Fig. 4 illustrates a side view of a modified `type of support for the die; Fig. 5 is a plan view of the Fig. 4l support; Fig. 6 is an elevation view of the support taken on the line 8-6 of Fig. 4; Fig. 'I is an enlarged plane view of the die proper illustrating one shape of die opening incorporating my invention and Fig. 8 is an enlarged plan view of the die proper illustrating another shape of die opening.

The enameling or coating apparatus shown in Fig. 1 comprises a container I for viscous coating material 2. Round or circular wire I to be coated is drawn from a pay-od reel 4 over a guide sheave 5 immersed within the liquid coating material 2, The wire leaves the container 'I with its surfaces coated with a non-uniform layer of coating material. In order to uniformly and concentrically spread the coating material over the wire and to remove excessive coating material therefrom the wire passes vertically through a die B fioatingly supported on a support 1 rigidly secured to the lower end of a baking oven 8. The latter has spaced parallel walls 9 and Ill and in the present example is heated by a plurality of electric heating elements II disposed within recesses of the walls 9 and III. A channel IZ/for the admission of air to the oven is formed in the wall 9. On its passage through the oven, the coating material is baked and in many instances the wire ls provided with several coatings. The wire therefore with its heat-hardend insulated coating of enamel thereon is passed over a driving sheave I3 and then recirculated through the coating material, additionalV dies having progressively larger openings therein, and the oven and upon baking of the last coating the wire is wound onto a take-up reel Il.

'I'he die support illustrated in Figures 2 and 3 comprises a pair of parallel fingers or rods I5 and I6 respectively supported by the separate parts of split block I8. Block I8 is maintained assembled about the enlarged cylindrical portion of a shoulder screw I9 by the biasing action of a resilient U-shaped springlll which partially encircles blockl I8 and exerts its biasing action in vertical slots in the side walls thereof. Shoulder screw I 9 is screwed into a tapped opening in L-shaped block 2| so that the shoulder of the Y screw is tightly bound by the thread engagement against the upper surface of block 2 I. The length of the enlarged cylindrical portion of .screw I9 is slightly greater than the thickness of block I8 so that as thus assembled block I8 and rods I5 and I8 are free to rotate in a horizontal plane about the vertical axis of screw I9. L-shaped block 2| is in turn rigidly fixed to support 1 in any Isuitable manner such as by screw 22.

The die proper comprises a pair of

cylindrical rollers

23 and 24 each of which has in the periphery thereof an identical annular groove having the shape of half a polygon such as half a square 25, more clearly -shown by Fig. '7, or half a hexagon 28 illustrated by Fig. 8.

Rollers

23 and 24 are respectively mounted on rods I5 and I8 and biased into contact, as shown. bythe biasing action of U-shaped spring 20 so that the matched grooves therein will form an enclosed die opening having the shape of a full polygon-as shown by Figure 7 or 8. 'I'he dimensions of the grooves are selected so that the minimum cross sectional dimension a of the enclosed opening will be approximately equal to the diameter of the circular wire or cable while the maximum cross sectional dimension b will be greater than the diameter of the wire. Thus the wire in passing through the die is centered in the die opening by the die itself while excess coating'material is removed from the wire with the exception of four beads, in the case of a square die opening, or 6 beads, in the case of a hexagonal die opening which I have found distribute themselves thereafter equally around the wire by surface tension whereby concentricity of the enamel film is assured. At this point it should be observed that the enclosed polygonal die openings illustrated are regular such as ya squareor a hexagon havlng equal sides and angles. 'I'he volume or cross sectional area of the beads of material on the wire permitted to pass through the die opening are thus equal which further assures concen.

tricity. It should also be observed that a pair of opposite angles of the enclosed polygon are formed by sides which intersect on the line of ings so lon'g as the cross sectional shape thereof is defined by a plurality of equally spaced centering points lying on the circumference of a circle approximately equal in diameter to the circular wire being coated which points are interconnected by surfaces lying outside the circumference to allow for passage of the beads of coating material. However, as previously pointed out, shapes other than the simple square or hexagon would probably considerably increase the manufacturing cost of the die.

The inside diameter of

rollers

23 and 24 is slightly greater than the diameter of rods I5 and I8 so that the rollers are both rotatably and slidably mounted thereon. Thus, to allow for whipping or lateral motion of wire 3 as it passes between sheaves 5 and I3 the support permits not only free rotary motion of the rods and roll- Although I have illustrated polygonal..

. allowed by the free slidable motion of the legs ers about screw I9 but free axial movement of the rollers along the rods is permitted as well.

. 4 ures 4, 5 and 6 comprises a relatively stiff but resilient hair pin shaped rod 21 upon the

legs

28 and 29 of which the

rollers

23 and 24 are respectively mounted. The rollers are maintained in contact by the inherent biasing action of the two parallel legs toward each other. For sup-- port of the hair pin shaped rod 21 so that the axis of the legs thereof will be in a horizontal plane, a pin is provided having a portion of reduced diameter 30 for insertion into an opening of support 3I which in turn may be rigidly mounted in any suitable manner on the wall of baking oven 8. At its upper end, the pin terminates in a T-shaped portion the transverse part 32 of which has a length equal to the maximum diameter of the pin and the longitudinal part 33 of which has a length slightly greater than the diameter of hair pin shaped rod 21. Adjacent the lower end of the pin, a transverse opening therethrough normal to the broad dimension of the T part at the upper end of the rod is provided into which a key or pin 34 is inserted. Rotary motion of the support pin within the opening of support 3I is resiliently prevented by the upward biasing action of spring 35 inserted between the 'shaped part 90 to the position indicated in Fig-5.

The rod 21 will thereafter be held between the -upper surface of collar 36 and the lower surfaces oi' the transverse portion 32 and inasmuch as the longitudinal part 33 of the T-shaped portion has a length slightly greater than the diameter of the rodv 21, the

legs

28 and 29 thereof will be free to slide axially, in contrast to the y main embodiment, as well as free to rotate about the longitudinal part of the T-shaped portion as a vertical axis. If desired,

rollers

23 and 24 may be ilxed in any suitable manner on the

legs

28 and 29 so as not to have slidable motion thereon but lateral movement of the rollers with the wire, passing therebetween, will nevertheless be proper. On the

other hand rollers

23 and 24 may be both rotatably and fslidably mounted on the legs as in the main embodiment.- 'I'hus a full floating suspension for the die is provided which is simple, inexpensive and quickly replaceable.

While I have, in accordance with the patent statutes, shown a particular embodiment of my invention and modifications thereof, other changes and modications will be obvious to those skilled in the art and I. therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

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

l. In an apparatus for coating wire, cable, and like work having a circular cross section, means for uniformly distributing a coating on said work of enamel, varnish, or lacquer material by virtue of the surface tension exhibited by said material including a pair of cylindrical rollers each of which has in the periphery there- The modied type of support illustratedinFgof an identical annular groove having a cross section defined by a plurality of equally spaced points lyins on the circumference of a circle interconnected by lines lying outside of said circumference, and means including a support shaft and a pair of spaced rods rotatably supported thereon for respectivelysupporting said rollers in contact-.relationship so that the axes thereof will be parallel, lie in a common horizontalplane and the 'matched grooves therein will form an enclosed die opening having a maximum cross sectional dimension greater than the work being coated and a minimum cross sectional dimension at least equal to the work being coated.

2. In an apparatus for coating wire, cable, and

like work having a circular cross section, means `ference, means including a support shaft and a pair of spaced rods rotatably supported thereon,

said rollers being respectively mounted on saidv rods whereby the axes of said rollers are main-A tained parallel and in the same horizontal plane and resilient biasing means to force said rollers toward each other so that the matched grooves therein will form an enclosed die opening lying in a horizontal plane and having a minimum,

cross-sectional dimension at least equal to the work being coated.

3. In an apparatus for coating wire, cable, and like work having a circular cross section,

means for uniformly distributing a coating on` said work of enamel, varnish or lacquer material by virtue of the surface tension exhibited by said material including a support pin, a pair of spaced and parallel rods the axes of which lie in the same horizontal plane, rotatably mounted on'said pin, a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove the cross section of which is defined by a plurality of spaced points lying on the circumference of a circle interconnected by lines lying outside said circumference. each of said rollers respectively mounted on vsaid rods with the grooves therein in alignment, and resilient biasing means to force said rods and said rollers toward each other so that the matched grooves therein will form an enclosed die opening lying in a horizontal plane, said enclosed opening having a maximum cross sectional dimension greater than the work being coated and a minimum cross sectional dimension at least equal to the work being coated.

4. In an apparatus for coating wire, cable, and like work having a round cross section, means for uniformly distributing a coating on said work of enamel, varnish, or lacquer material by virtue of the surface tension exhibited by said material including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove having the shape of half a polygon,'a vertically disposed support pin, a pair of spaced rods rotatably supported on said pin, said rollers being respectively mounted on said rods whereby the axes of said rollers are maintained parallel and in the same horizontal plane and resilient biasing means to force said rollers in contact so that the matched grooves therein i will form an enclosed horizontal die opening having the shape of a polygon with a maximum cross sectional dimension greater than the work being coated and a minimum cross sectional dimension at least equal to the work being coated.

5. In an apparatus for coating wire cable, and like work having a round cross section, means for uniformly distributing a coating on said work of enamel, varnish, or lacquer material by virtue of the surface tension exhibited by said material including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove the cross sectional shape of which is defined by the full sides of half a polygon, a support pin, a pair of spaced rods rotatably supported on said pin, said rollers being respectively mounted on said rods whereby the axes of said rollers are maintained parallel and in the same horizontal plane Aand resilient biasing means to force said rollers into co- Y operative rolling contact so that the matched grooves therein will form an enclosed horizontal die opening therebetween having the shape of a polygon a pair of opposite angles of which are formed by sides intersecting on the line of contact of said rollers, said enclosed die opening having a minimum cross-sectional dimension at least equal to the work being coated.

Y 6. In an apparatus for coating wire, cable, and like work having a circular cross section, a pair of spaced and parallel rods rotatably mounted so that said pair of rods will be supported in parallel and spaced relationship with the axes thereof in a common horizontal plane and will be free to rotate about a common vertical axis, means for uniformly distributing a coating on said work including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove having the shape of half a polygon, each of said rollers respectively mounted rotatably and slidably on said rods so that the grooves therein may be aligned and resilient biasing means to force said rollers in contact so that the matched grooves therein will form an enclosed die opening therebetween having the `shape of a polygon, said enclosed opening having a maximum cross sectional dimension greater than the work being coated and a minimum cross sectional dimension at least equal to the work being coated.

7. In an apparatus for coating wire, cable, and like work having a round cross section, means for uniformly distributing a coating on said work including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove having the shape of half a polygon, said rollers respectively mounted on the legs of a resilient hair pin shaped rod the legs of which are inherently biased toward each other to force said rollers in contact so that the matched grooves therein will form an enclosed die opening having the shape of a polygon with a maximum cross sectional dimension greater than the work being coated and a minimum cross sectional dimension at least equal to the work being coated, said hair pin shaped rod being slidably and rotatably mounted with the axes of the legs in a common horizontal plane so that said legs will be free to both slide axially and rotate about a vertical axis.

8. In an apparatus for coating wire, cable, and like work having la circular cross section, means for uniformly distributing a coating on said work of enamel, varnish, or lacquer material by virtue of the surface tension exhibited by said material including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove the cross sectional shape of which is defined by the full sides of half a square and means including a support and a pair of spaced rods rotatably supported thereon for supporting said rollers in contact relationship so that the axes of said rollers will be parallel and the matched grooves therein will form an enclosed horizontal die opening therebetween having the shape of a square a pair of opposite angles of which are formed by sides intersecting on the line of contact of said rollers, said enclosed opening having a minimum cross-sectional dimension 'at least equal to the work being coated.

9. In an apparatus for coating wire, cable, and like work having a circular cross section, means for uniformly distributing a coating on said work of enamel, varnish, or lacquer material by virtue of the surface tension exhibited by said material including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove the cross sectional shape of which is defined by the full sides of half a hexagon and means including a support and a pair Voi? spaced rods rotatably supported thereon for supporting said rollers in contact relationship so that the axes of said rollers will be parallel and the matched grooves therein will form an enclosed horizontal die opening therebetween having the shape of-a hexagon a pair of opposite angles of which are formed by sides intersecting on the line of contact of said rollers, said enclosed die opening having a minimuml crosssectional dimension at least equal to the work being coated.

10. In an apparatus for coating wire, cable, and like work having a round cross section. means for uniformly distributing a coating on said work including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove the cross sectional shape of which is defined by the full sides of half a square, said rollers respectively mounted on the legs of a resilient hair pin shaped rod the legs of which are inherently biased toward each other to force said rollers into cooperative rolling contact so that the matched grooves therein will form an enclosed die opening therebetween having the shape of a square a pair vof opposite angles of which are formed by sides intersecting on the line of contact of said rollers, said hair pin shaped rod being slidably and rotatably mounted with the axes of the legs in a common horizontal plane so that said legs will be free to both slide axially and rotate about a vertical axis.

11. In an apparatus for coating wire, cable, and like work having a round cross section means for uniformly distributing a coating on said work including a pair of cylindrical rollers each of which has in the periphery thereof an identical annular groove the cross sectional shape of which is defined by the full sides of half a hexagon, said rollers respectively mounted on the legs of a resilient hairpin shaped rod the legs of which are inherently biased toward each other to force said rollers into cooperative rolling contact so that the matched grooves therein will form an enclosed die opening therebetween having the shape of a hexagon a pair of opposite angles of which are formed by sides inter-V secting on the line of contact of said rollers, said hair pin shaped rod being slidably and rotatably mounted ,with the axes of the legs in a common horizontal plane so that said legs will be free to bzgl slide axially and rotate about a vertical a ROBERT H. BENI-IAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 270,709 Wardwell Jan. 16, 1883 1,759,850 Janicki' May 27, 1930 1,957,942 Convers May 8, 1934 2,287,589 Wilson et al. June 23, 1942 2,433,642 Bailey Dec. 30, 1947