US3779474A

US3779474A - Machine for winding foil ribbon coils

Info

Publication number: US3779474A
Application number: US00174141A
Authority: US
Inventors: R Harelson
Original assignee: Emerson Electric Co
Current assignee: Emerson Electric Co
Priority date: 1971-08-23
Filing date: 1971-08-23
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18

Abstract

A device for winding electrical coils and having particular use in winding a transformer coil consisting of interleaved layers of a strip of insulative material and a ribbon of conductive foil. One or two prewound foil reels are slidably mounted on a carriage for (independent) movement to a winding position adjacent the piece on which the coil is wound and to a second position spaced radially from the coil. The piece on which the coil is wound is rotatably held on a reeler assembly. A follower piece is biased into engagement with the outer face of the prewound reel and defines the take-off point for the foil. Nothing else touches the foil between the reel and the coil. One or two prewound reels of insulative tape are each biased into contact with a second follower piece, and the insulative tape is interleaved with the conductive ribbon. When a coil is wound except for about a turn and a half, the dereeler assembly is moved to its second position, a lead is secured to the foil, the foil is cut and winding of the coil is completed. A second coil or pair of coils may be wound on the same piece by shifting the dereeler assembly axially of the coils previously formed.

Description

United States Patent p191 I-Iarelson [111 3,779,474 1 Dec. 18, 1973 MACHINE FOR WINDING FOIL RIBBON COILS [75] Inventor: Robert G. Harelson, Florissant, Mo.

[73] Assignee: Emerson Electric Co., St. Louis, Mo.

22 Filed: Aug. 23, 1971 [21] Appl. No.: 174,141

Related US. Application Data [63] Continuation of Ser. No. 800,521, Feb. 19, 1969,

abandoned.

[52] [1.8. CI. 242/56.l, 29/203 {-51 1 Int. Cl. B65h [58] Field of Search 242/56.1, 703,706, 242/673,.582, 58.1; 29/203, 605, 606, 607, 25.42

[56] References Cited I UNITED STATES PATENTS 3.425.641 2/1969 Gallet et al. 242/56.1 3,058,201 10/1962 Richardson, Jr.. 242/703 X 3,474,370 10/1969 Lightner 242/56.1 X

2,269,405 1/194; Boucher 242/103 Deputy 242/673 X Looser 242/582 Primary Examiner-Billy S. Taylor AttorneyPolster & Polster [57 ABSTRACT A device for winding electrical coils and having particular use in winding a transformer coil consisting of interleaved layers of a strip of insulative material and a ribbon of conductive foil. One or two prewound foil reels are slidably mounted on a carriage for (independent) movement to a winding position adjacent the piece on which the coil is wound and to a second position spaced radially from the coil. The piece on which the coil is wound is rotatably' held on a reeler assembly. A follower piece is biased into engagement with the outer face of the prewound reel and defines the take-off point for the foil. Nothing else touches the foil between the reel and the coil. One or two prewound reels of insulative tape are each biased into contact with a second follower piece, and the insulative tape is interleaved with the conductive ribbon.

5 Claims, 6 Drawing Figures PATENIEDHEC 18 ms $779,474 SHEET 2 OF 3 FIG. 5

swaiiii G- 6 ROBERT a. HARE 6 PMENTEDUEC 18 I973 SHEET 3 [IF 3 I 1 MACHINE FOR WINDING FOIL RIBBON COILS BACKGROUND OF THE INVENTION This invention relates'to a device for winding electrical coils of the type in which a thin, flat ribbon of conductive material is convolutely wound in an axially aligned coil. Because theelectrically conductive ribbon is frequently very thin, it is often referred to as a foil ribbon, and these machines are often referred to as foil coil winders. Generally, the foil ribbon is interleaved with an'insulative tape of slightly greater width than the foil ribbon, although successive windings of the foil ribbon may also be insulated by other means, such as bonding an insulative strip to the foil before the coil is wound or coating the foil ribbon with a resin. Although the high fill factor of foil coils, which allows the use of aluminum foil or strip rather than copper wire without sacrificing size or efficiency, makes their use in many applications highly desirable, it has heretofore been impractical to produce foil coils having a small enough conductor width, on the order of one inch or less, for most applications. Therefore, the use of foil coils has heretofore been generally restricted to large transformers, such as those used in electrical power distribution systems, The greatest difficulty in making smaller width coils has been in maintaining'a highly accurate-axial alignment of the convolute coil, in order to prevent shorting of the windings and loss of efficiency. The use of edge guides almost invariably results in damaging the delicate foil, and other methods of guiding the foil accurately have been equally ineffective, or prohibitively expensive, or both.

Machines known heretofore for winding foil coils are also unable to wind coils directly onto the form on which the coil is ultimately to be mounted, particularly when a part of that form extends considerably radially beyond the coil, as does, for example, the leg of a transformer core made up of L-laminations. Instead, the coils are wound on an arbor and carefully slipped onto the ultimate form, generally a'magnetically permeable core. I v

Machines known heretofore have also been capable of winding only a single coil at a time.

One of the objects of this invention is to provide a 'machine and method for winding foil coils which are axially aligned to'a high degree of accuracy, even with foil ribbon which is relatively narrow, on the order of one inch or less.

Another object of this invention is to provide such a machine and method which allow winding coils directly onto a magnetically permeable core structure, even one of odd shape.

Still another object is to provide such a machine and method which permit winding more than one coil on a single core structure simultaneously.

Other objects will occur to those skilled in the art in light of the following description andaccompanying drawings. I

SUMMARY OF THE INVENTION In accordance with this invention, generally stated, a machine and method for winding axially aligned, convolute foil coils are provided in whicha prewound reel of electrically conductive ribbon is moved from a first position adjacent a driven reeler assembly, for winding the coil, to a second position, axially aligned with the first position, radially'spacedfrom the reeler assembly.

The term reel isused herein to mean any prewound roll of strip material, whether it is supplied wound on a spool or without any support structure. The term foil is used herein to designate any thin conductive material, and the term ribbon to designate a strip of foil. The term axially aligned designates alignment in a plane normal to the axis of rotation of the coil being wound. Thus, the expression axially aligned, convolute foil coils is simply a (redundant) way of expressing the fact that the turns of the foil coil are wound upon themselves, so that the edges of the turns arealigned in a plane perpendicular to the axis of the coil, rather than being helical. Likewise, as applied to the two positions of the prewound reel the term axially aligned indicates that the reel is not shifted in a direction parallel to the axis of rotation of the coil being wound, but rather moves in a plane normal to that axis.

In the first position of the prewound reel the outer face of the reeled ribbon is biased into engagement with a follower, and the point of contact between the follower and the prewound reel defines a take-off point for the ribbon from the reel. The prewound reel is movably supported by a foil dereeler assembly movably mounted on a carriage assembly. Thedereeler assembly includes a brake, and the brake and follower provide the complete means for tensioning the conductive ribbon. By providing a winding position for the'pre wound reel adjacent the driven reeler assembly on which the coil is wound, preferably sufficiently close that the distance between the take-off point from the reel and the initial contact point on the coils is less than the initial diameter of the largest prewound reel receivable on the reeler assembly, the machine and method of this invention allow a perfectly axially aligned coil to be wound, without the useof any auxiliary' alignment equipment.

In the preferred embodiments, the conductive ribbon is interleaved with an insulative tape of slightly greater width than the conductive ribbon. The insulative tape is supplied to the reeler assembly from a prewound reel which is carried by a tape dereeler assembly. The reeled tape is preferably biased into engagement with a tape follower for controlling the tension of the tape, and is located on an opposite side of the reeler assembly such that when-the dereeler assembly is in its first winding position, a line connecting the-center of rotation of the prewound reel of conductive ribbon with that of the coil being wound forms an angle of greater than ninety degrees with a line connecting the center of rotation of the coil being wound with that of the prewound reel of tape.

In some of the preferred embodiments of this invention, 'the driven reeler assembly is provided with a chuck which grasps the laminations of a transformer core. Spacers may then be placed on the laminated core and a coil wound directly onto the core. Also in these embodiments, a pair of independently movable dereeler assemblies are slidably mounted on .a carriage assembly and two coils arewound on the core simultaneously. The dereeler assemblies are also axially movable to wind a second pair of coils axially spaced from the first pair of coils.

In some of the preferred embodiments,the follower,

aroller, is fixed with respect to the reeler assembly and the prewound reel is biased into engagement with it.. In

another embodiment, the follower, a shoe, is carried by the dereeler assembly and is continuously spring biased into contact with the outer face of the reeled ribbon.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings,

FIG. 1 is a view in front elevation of one illustrative embodiment of coil winding machine of this invention, for use in practicing some aspects of the method of this invention;

FIG. 2 is a top plan view of the device shown in FIG.

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a view in front elevation of a second embodiment of machine of this invention for use in practicing further aspects of the method of this invention;

FIG. 5 is a top plan view of the device shown in FIG. 4; and

FIG. 6 is a fragmentary view in side elevation of another embodiment of machine of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and in particular to FIGS. 1-3, reference numeral 1 indicates one illustrative embodiment of foil coil winding machine of this invention. The machine 1 includes a reeler assembly 10 driven by a power train 20, a foil dereeler assembly 30 mounted on a carriage assembly 40, a tape dereeler assembly 50, and a lead attachement assembly 60. The reeler assembly 10, drive train and carriage assembly 40 are all securely mounted to a base 70. The tape dereeler assembly 50 and the lead attachment assembly 60 are pivotally mounted on the base 70, and the foil dereeler assembly is slidably mounted on the carriage assembly 40.

The reeler assembly 10 includes a bedplate 11 on which a spindle 12 is journalled in a bearing 13 and a bearing 14. The spindle 12 is horizontal and has a free forward end 15 on which a coil form 16 is removably mounted, for rotation with the spindle l2. Spacers 17 provide proper axial positioning of the coil form 16. The coil form 16 is illustratively made of an insulative material such as stiffened asbestos and is illustratively square in cross-section, for winding square coils. The free end 15 of the spindle 12 is therefore square to fit the inside of the coil form 16. A removable cap 18 holds the coil form 16 in place on the spindle 12. Legs 19 on the forward spacer 17 and cap 18 aid in initial alignment of a coil being wound on the form, but perform no other guidance function.

The spindle 12 is rotated by a variable speed motor 21 of the drive assembly 20, through a belt 22 around a pulley 23 on the rearward end of the shaft 12. A brake 24 and clutch 25 on the spindle 12 provide smooth and controlled stopping and starting of the spindle 12.

The carriage assembly 40 includes a pair of

support rods

41 and 42, which are rigidly held at their ends by blocks 43. The blocks 43 are secured to the base 70 and hold the

support rods

41 and 42 spaced above it. The

support rods

41 and 42 are parallel with each other, and the axis of each lies in a plane normal to the spindle 12, that is, each is axially aligned as that term has been defined.

The dereeler assembly 30 includes a first sleeve 31 and a second sleeve 32 slidably mounted respectively on the

support rods

41 and 42. The

sleeves

31 and 32 are joined by a connecting plate 33. A vertical support bracket 34 on the forward sleeve 31 carries on its rearward face a heavy sleeve 35 in which is journaled a shaft 36, and carries on its forward face a bracket 37. The forward end of the shaft 36 is journaled in the forward face of the bracket 37. The bracket 37 also forms a housing in which is secured a magnetic clutch or brake 38 for controlling the resistance to rotation of the shaft 36. The magnetic clutch 38 is continuously adjustable by means of a potentiometer, not shown. Suitable spacers 39 on the distal, rearward, end of the shaft 36 provide exact axial alignment, as that term has been defined, of a prewound reel of conductive foil ribbon 81 with the coil winding form 16. The prewound reel 80 is slipped on to the distal end of the shaft 36 and held by a lock 39a. By way ofillustration, the prewound ribbon may be bare aluminum 1 l/l6 inches wide and 0.008 inch thick.

The entire foil dereeler assembly 30 is movable to a first position, shown in solid lines in FIG. 1, adjacent the reeler assembly 10 and to a second position, shown in broken lines in FIG. 1, spaced from the reeler assembly 10. The foil dereeler assembly 30 is biased toward its first position by a hanging weight 83 secured to the connecting plate 33 of the foil dereeler assembly 30 by a chain 85 over a sprocket 87 on the base 70. When the foil dereeler assembly 30 is in its forward position, the outer face of the prewound reel 80 is biased into engagement, at a point 82, with a follower in the form of a roller 91 freely rotatably supported by a bracket 93 extending forwardly from the bedplate 11 of the reeler assembly 10. The axis of rotation of the roller 91 is parallel with that of the spindle 12 of the reeler assembly and the shaft 36 of the foil dereeler assembly. The axis of rotation of the roller 91 and the axis of rotation of the reel 81 lie in a plane which is approximately horizontal, and the coil winding form 16 is positioned above and slightly to the left, as viewed in FIG. 1, of the point of contact between the roller 91 and the reel 80. Therefore, when a free end of the ribbon on the reel 80 is secured to the coil winding form 16, and the form 16 rotated in a counterclockwise direction as viewed in FIG. 1, the roller 91 displaces upward slightly the takeoff point of the ribbon 81 from the reel 80. It will be seen that the ribbon contacts the roller 91 over a short are of its curved surface.

The dereeler assembly 30 may be moved manually, to the right as viewed in FIG. 1, to its second position shown in broken lines in FIG. 1, and locked by a latch 95 to a support block 43. As will be explained more fully hereinafter, in the second position of the dereeler assembly 30, the reel 80 should be spaced from the reeler assembly 10 a distance at least equal to the width of the lead attachment assembly 60.

By way of illustration, the largest prewound reel 80 usable on the dereeler assembly 30 may be 12 inches in diameter. The greatest length of ribbon 81 from the takeoff point 82 to the point of contact with the coil being wound, as shown in FIG. 1, may be about 7 inches. The length of ribbon between these points will of course vary slightly as the coil form 16 turns through a quarter revolution.

The tape dereeler assembly 50 includes a pair of parallel axially aligned rails 51 each including a set of holes 52. An upright H-shapd yoke 53 is pivotally mounted between the rails 51 by pegs 54 thorugh one pair of holes 52 in the rails and through one pair of a set of mating holes 55- in the lower part of the legs of the H- shaped yoke 53. A shaft 56 is held by lock pins 57 in seats 58 at the upper margins of the legs of the H- shaped yoke 53. The shaft 56 freely rotatably supports a prewound reel 84 of insulative tape 86. A spring 92 secured to the adjacent support block 43 of the support rod 42 and to the cross brace of the yoke 53 biases the prewound 'tape reel 84 into contact with a follower in the form of a roller 97 freely rotatably mounted on a forwardly extending bracket 99. The axis of rotation of the tape roller 97 lies in a common horizontal plane with that of the roller 91 and the prewound reel 80. The roller 91 and roller- 97 are arranged symmetrically with respect to the spindle -12 of the coil reeler assembly 10.

The holes 52 in the support rails 51 and the holes 55 in the yoke 53 are spaced apart a distance such that,- when the .yoke 53 is pivotally secured between any of the pairs of holes 52 in the rail 51, the shaft 56 and the axis of the'roller 97 lie on the same arc having its center atthe pin 54. Thus, for each position of the yoke 53, the point of contact between the tape reel 84 and the roller-97, with respect to the fixed structure of the machine, remains the same as the roll of tape 84 unwinds. Therefore, moving the yoke 53 from one position to a hole 52 further removed from the vertical increases the resistance to rotation of the tape reel 84 essentially independently of the diameter at that instant of the tape reel 84. Thus, tensioning of the tape may be kept sufficiently constant by moving the yoke to holes spaced farther from the reeler assembly as the diameter of the tape roll 84 decreases.

. The contact point 89 between the tape reel 84 and the roller 97 like wise defines the takeoff point of the tape from the reel 84. However, it will be seen that the tape 86 rides on the roller 97 through a much greater arc, on the order of 60, than does the foil 81 on the roller 91. t

When the tape86 is attachedto the coil form 16 and the form 16 rotated counterclockwise as viewed in FIG. 1, the distance from the takeoff point 89 to the point of contact with the coil is, illustratively, a maximum of about 6% inches.

Merely by way of illustration, the tape 86 may be a woven fiberglass tape 1% inch wide and 0.004 inches thick. The maximum diameter of the tape roll may be 5 inches.

Also by way of illustration, the rollers 91-and 97 may be 2% inch in diameter and their axes of rotation may be spaced about 6 inches from each other and from the axis of rotation of the spindle 12. The rollers 91 and 97 may be made of hard rubber.

The lead attachement assembly 60 includes a spot welder 61 having an open jaw 63 for receiving the conductive ribbon 81. The welder 61 is pivotally mounted to the base 70 on an axis parallel to the rearward support rod 42 of the carriage assembly 40, and spaced rearward of it. The welder 61 is normally rotated rearward to a first stop position, as shown in FIG. 2, and when the dereeler assembly 30 is moved to its second position spaced from the reeler assembly 10, the welder 61 is swung forward to a second position, in which the open jaw 63 is axially aligned with the foil ribbon 81 for welding a lead to the ribbon 81.

I this invention, is as follows.

dereeler assembly 30 is in its second position, radially spaced from the reeler assembly 10. The diameter of the reel 80 is preferably the maximum usable, i.e., l2

inches, for efficiency of operation. The prewound tape roll 84 is placed on the shaft 56 of the tape dereeler assembly 50 and the shaft 56 is snapped into its slots 58 in the yoke 53. Each prewound reel of conductive rib-- bon and insulative tape, of course, is used for winding a large number of coils. A reel isreplaced'only when it contains insufficient material to wind another coil.

A coil form 16 is then slipped onto the squared end 15 of the spindle 12 of the reeler assembly 10, along with the proper spacers 17 and secured by the cap 18. While the dereeler assembly 30 is still in its second position, the welder 61 is moved to its second position, in which its open jaw 63 is axially aligned with the foil ribbon 81. The loose end of ribbon on the reel 80 is manually placed in the jaw 63 for welding a start lead 96 to the ribbon 81 at a point spaced a desired distance, illustratively one inch, from the end of the ribbon, to give the desired placement of the lead 96 asexplained hereafter. It will be seen that the welding operation is performed a sufficient distance away from the coil form 16 to prevent any danger of injury to it.

When the lead 96 has been welded to the ribbon 81, the lead attachment assembly is swung back to its first position, and the latch 95 is released to allow the dereeler assembly 30 to move to its first position adjacent the coil form 16, with the ribbon reel in contact with the roller 91 and a short strip of ribbon 81 extending above the point of contact. The loose end of the woven glass tape 86 on the roll 84 is brought over the roller 97 and manually held to the free end of the ribbon 81. The free end of the glass tape 86 preferably extends about one-half inch beyond the ribbon 81. The ends of the tape 86 and ribbon 81 are then placed over a corner of the form 16, with the lead 96 lying at the center of an adjacent face of the form and extending between legs 19 of the cap 18. A strip of polyester pressure-sensitive tape,not shown,is thensecured in axial alignment with the coil form 16 over the lead 96, the end of the ribbon 81, the end of the tape 86, and the adjacent face of the coil form 16, for securing the tape 86 and ribbon 81 to the form 16,.and for reinforcing the welded joint between the ribbon 81 and thelead 96. If desired, a piece of insulation may be placed along the attached part of the lead 96 and held by the pressuresensitive tape. The form 16 is then rotated by hand counterclockwise, as viewed in FIG. 1, to reduce the strain on the pressure-sensitive tape when the power train 20 is energized. The motor 21 is then energized and the clutch 2S engaged to give a smooth start. The coil form 16 quickly reaches a predetermined rate of revolution, which is preferably on the order of 30 revolutions per minute.

It will be seen that the reels, rollers, and coil form are so placed that the take up angles of the ribbon 81 and tape 86 onto the coil form 16 are about90 degrees separated..Therefore, the tape 86 is always laid completely across a face of the coil and around'a trailing corner before the ribbon 81 is laid over it. Therefore, there is no slippage between the tape 86 and the ribbon 81, and

tensioning of each component is essentially independent of the other.

It will also be seen that the tensioning of the tape 86 and ribbon 81 will vary slightly as the coil is wound. This variation,'however, has been found not to affect the finished coil adversely. When all but a few of the desired number of turns have been wound on the coil, the electric motor 21 is de-energized and the brake 24 applied to stop rotation of the coil form 16 smoothly and quickly. About a turn and a half should remain to be wound when the coil form 16 stops rotating, The dereeler assembly 30 is then moved to its second position spaced from the reeler assembly 10 and its latch 95 is secured to the adjacent support block 43. The reach of ribbon 81 between the coil 98 and the reel 80 iscarefully lifted, the lead attachment assembly 60 is carefully swung forward, and the ribbon 81 carefully placed in theopen jaw 63. A finish lead is then welded to the ribbon 81, the coil form 16 is turned ashort way by hand, and a second start lead is welded to the ribbon 81. The lead attachment assembly 60 is then swung back to its first position. The ribbon 81 is then cut between the finish lead and the second start lead,

about one-eighth inch from the finish lead, and the coil' 98 is completed by manually turning the form 16. The glass tape 86 is cut about one-half inch beyond the end of the ribbon 81. A strip of pressure-sensitive polyester tape is then wrapped entirely around the coil, securing a short strip of insulation over the finish lead if required'. The cap 18 holding the coil form 16 on the spindle 12 is then removed and the coil form 16 is taken off the spindle 12. The coil 98 may then either be set aside or immediately slipped over a magnetically permeable core, such as a laminated L-shaped transformer core half.

If it is desired to wind coils around the first coil 98 wound on a coil'form 16, these coils may be wound before the coil form 16 is removed from the spindle 15. Spacers may be placed at the comers of the coil 98, and the second coil wound in the same manner. If the first coil wound on a coil form 16 is wide, it may be desired to wind second and third coils, each half the widthof the first coil, over the first coil. A new foil reel and new tape reel, each half the'width of the corresponding first reel, are placed on their respective dereeler assemblies with spacers holding them forward. The second coil is then wound. After leads have been attached, the third coil is wound by moving the dereeler spacers to shift the foil and tape reels rearward a distance equal to the width of the second coil, and then winding the third coil in the same manner as the first two. Usually, of course, it is preferable to wind a large number of coils of the same width at the same time and then to wind coils of a different width over them, in order to avoid frequent handling of the prewound reels.

Successive coils are wound in precisely the same manner. It will be seen that as the diameters of the

prewound reels

80 and 84 decrease, the same resistance to their rotation creates a greater tensioning of the ribbon 81 and tape 86 respectively. The ribbon 81 is particularly sensitive to changes in tensioning, whereas the tape 86 is remarkably insensitive to the changes encountered in normal operation. Therefore, the. magnetic clutch 38 must be adjusted to a lower (freer tuming) setting by means of its potentiometer as the reel 81 unwinds, and the yoke 53 of the tape dereeler assembly may be shifted to holes 52 closer to the reeler assembly 10, that is from the position shown in broken lines in FIG. 1 to the position shown in solid lines in FIG. 1. Although it is possible to provide a feedback system from the drive train 20 for automatically adjusting the potentiometer of the magnetic clutch 38, it has been found that one or two manual stepwise adjustments of the potentiometer are satisfactory.

It will also be seen that if it were desired to provide a coil wound in the opposite direction (that is, with leads extending from the opposite side), it is possible to reverse the direction of rotation of the coil form 16. In this case, the ribbon 81 and the tape ,86 follow paths which are mirror images of the path followed by the other when the coil form 16 is rotated counterclockwise as viewed in FIG. 1. Therefore, the tape 86 will be laid over the ribbon 81, but the angle between the tape 86 and ribbon 81 will again be about 90, and their tensioning will again be essentially independent of each other. Although the particular. reeler assembly 10 of this illustrative embodiment makes winding the coils in opposite directions generally unnecessary, this feature may be useful with other reeler assemblies, as explained hereinafter.

Referring now to FIGS. 4 and 5, reference numeral 101 indicates a second illustrative embodiment of foil coil winding machine of this invention, for use in practicing further aspects of the method of this invention. The machine 101 includes a reeler assembly driven by a power train 120, a first dereeler assembly 130, a second dereeler assembly 230, a tape dereeler assembly 150, a lead attachment assembly 160, and a base 170. The lead attachment assembly 160 is mounted on a lead assembly carriage 260, and a forward part of the reeler assembly 120, dereeler carriage assembly 140, reelerassembly carriage 210, and lead attachment carriage 260 are all secured to the base 170. The rearward part of the reeler assembly 110 is secured to the drive assembly 120 for rotation with it.

The forward part of the reeler assembly 110 includes a pillow block 111 slidably mounted on the reeler assembly carriage 210 for movement to a rearward position (toward the rearward half of the reeler assembly 110), shown in FIG. 5, and to a forward position (away from the rearward half of the reeler assembly 1 10). The pillow block 11 rotatably supports a forward chuck 112 the jaws 113 of which are tightenable by a clamp screw 114 for grasping the forward end of a structure to be wound. The rearward face of the chuck 112 carries a forward winding plate 115 having a large slot 116 for receiving a structure to be wound, and a small slot 1 17 for receiving a lead of a coil being wound.

The rearward part of the reeler assembly 110 includes a chuck 118, which may be a standard two-jaw chuck, the jaws 119 of which are adapted to grasp the rearward end of the structure being wound. A rearward winding plate 121 on the chuck 118 includes a slot 122, which in use is aligned with the slot 116 on the forward plate 115, and a small slot normal to the slot 122 for receiving a lead of a coil being wound. The chuck 118 is secured to a rotating shaft 123 of the power train 120. The axis of rotation 124 of the shaft 123 is, of course, the axis of rotation for all of the rotating parts of the reeler assembly 110,

The drive train also includes a magnetic clutchbrake 125, for stopping the rotation of the shaft 123 smoothly and accurately, and for releasing the shaft for free manual rotation when desired. It also includes a variable spe'edelectric motor 126 connected tothe shaft 123 by a pulley 127 for controlling the rate of rotation of the shaft 123 to a precontrolled, continuously variable, rate, and a'magnet wheel 128 carrying around its margin a set of ten magnets l28a-which cooperate with a magnetically triggered counter switch 129 for activating the clutch-brake 125 and thus stopping the rotation of the reeler assembly 110 after a pre-set number of revolutions.

Each of the

dereeler assemblies

130 and 230 includes a bedplate 131 slidably mounted on the carriage assem bly 140. The bedplate 131 of the forward dereeler assembly 130 is mounted on a pair of axially aligned shafts 141 of the carriage assembly 140, and the bedplate 1310f the rearward dereeler assembly 230 isslidably mounted on a pairof axially aligned shafts 142.

The

shafts

141 and 142 are mounted to the base 170, g

and spaced from it, by a pairof support blocks 143. Each bedplate 131 is U- shaped in a cross-section taken along a plane perpendicular to the

carriage shafts

141 and 142. The upstanding arms 132 of each of the U- shaped bedplates- 131 have mounted between them a pair of horizontal support rods 133, the axes of which are normal to the axis of

thesupport shafts

141 and 142 in plan view, as seen in FIG. 5. Slidably mounted .on the support rods 133 on each

dereeler assembly

130 and 230 is a bifurcated support bracket 134, the branches 135 of which have journaled between them a shaft 136 and rigidly support between'them a magnetic clutch 137 for controlling the resistance to rotation of the shaft 136. The axes of rotation 138 ancl 238 respectively of the shafts 136 of the

assemblies

130 and 230 are parallel to the axis of rotation 124 of the reeler assembly 110. At theirfree, axially inner ends (the rearward end for the forward assembly 130 and the forward end for the rearward assembly 230) the shafts 136 have removably mounted on them appropriate spacers in the form of spools 139 having threaded retainer caps 139a for securing prewound reels 180 of foil ribbonv 181 to the inner faces of the spools 139. Each dereeler assemreeler assembly 110, by means of a rod arm at the axially outer end of the rod 233 and a spring arm 235 at the axially inner end of the rod 233. A spring 236'from the spring arm 235 to the'shoe arm 232 biases the shoe 231 into contact with the outer face of the reel 180.

Each of the

dereeler assemblies

130 and 230 is independently movable from a first position adjacent the reeler assembly 110 to a second position spaced from' it. In FIGS. 4 and 5, the forward dereeler assembly 130 is in the second position and the rearward dereeler assembly 230 is in the first position. In this embodiment, the dereeler assemblies are alternatively biased toward their first position and toward their second position by a pneumatic control system which includes a pair of air cylinders 144 powered by a standard industrial source of compressed air, not shown. The air cylinders 144 are clevis type cylinders and are controlled by a standard four-way double solenoid valve, not shown, for electrically controlling the direction 'of'bias from a control panel 145. When one of the dereeler assemblies is moved to its first position adjacent the reeler assembly an arm 146 from its bedplate 131 through a slot 172v in the base 170 to the clevis of its air cylinder 144 contacts an adjustable stop 147 and is continuously biased into engagement with it until the control is reversed and the dereeler assembly moved to its second position. When it reaches its second position, its bedplate 131 contacts a limit switch 148 and thereby disconnects the air supply to its air cylinder 144. ln-this second position, the bracket 134, hence the reel 180, can be moved forward or rearward on the bedplate by pneumatically releasing a spring loaded latch pin 237 mounted through the bedplate 131 and extending into one of two holes in the bracket 134. The bracket 134 and prewound reel 180 are thereby movable to an inward position or an outward position. The latch pin 237 is released by one of a second pair of pneumatic cylinders 238. Energizing the control solenoid of one of the air cylinders 238 causes it sequentially to extend and to retract a- 'magnet which engages and withdraws the latch pin 237. The reel 180 and its support structure may then be shifted .to the other'position before the magnet retracts below the level of its housing 239 and releases the latch pin 237. The support bracket 134 may then be shifted until the latch pin 237 snaps into place. As shown in FIG. 5, the first dereeler assembly 130 is in its outward position and the second dereeler assembly 230 is in its inward position. lt will be seen that if both dereeler assemblies are moved to their inward positions, using ribbon and spools of the width shown, the reels would be separated only by the extremely thin keeper nuts 139a and could wind axially aligned coils having their conductors extremelyclose to each other. It will also be seen that coils of slightly greater than twice the width of the coils shown in FIG. 5 could be wound simply by moving the support structure of the second dereeler assembly 230 to its outward position. Of course, by changing the axial dimension of the spools 139, either two or four coils of quite varying width can be wound.

. The tape dereeler assembly 150 includes a pair of rotatable shafts 151 snapped into a pair of

support structures

152 and 252 secured to the base 170. The support structure 152' 'is positioned forward of the support structure 252 and radially nearer the reeler assembly 110. It is also somewhat shorter than the support structure 252. Tape reels 184 of insulative tape 186 are positioned on the shafts 151 by spacers 156. The axial positions of the reels 184 can be changed by substituting new spacers 156 and by switching them to the opposite sides of the tape reels. Each tape reel is individually tensioned by a paddle 157 biased by a spring 158 into contact with the outer face of the prewound tape reel 184 radially away from the reeler assembly 110. The spring 158 is secured between the paddle 157 and an adjustment rod 159, which may be rotated to vary the tension supplied by the spring 158. As in the first embodiment, it has been found that adjustment of the tensioning device for the tape 186 is not normally necessary.

The axes of rotation and 255 of the tape reels i '186 are parallel with the axis .124 of the reeler assembly The lead attachment assembly 160 includes a spot welder 161 having an open jaw' 163 for receiving conductive ribbon 181 wound on the reels-180. The welder 161 is slidably'mounted on its carriage 260 by sleeves 165 on a support structure 167; When the

dereeler assemblies

130 and 230 are moved to their second positions, the lead attachment assembly 160 is movable from a rearward position behind the second dereeler assembly 230 to a forward position in which its jaw 163 encompasses'ribbons- 181 from both dereeler assemblies, regardless of the widths of the ribbon on the dereeler assemblies. For this purpose, the lower portion of the welder support 167 is cut back to the forward margins of the sleeves 165, to clear the rearward shaft 142 of the dereeler carriage assembly 140.

Merely by way of illustration, theribbon 181 on the reels 180 may be the same as that on the reel 80 of the first illustrative embodiment, that is, bare aluminum 1 1/16 inch wide and 0.008 inch thick. The tape 186 may then be the same as the tape 86 of the first illustrative embodiment, that is, woven fiberglass 1% inch wide and 0.004 inch thick. The ribbon reel 180 may have an initial diameter of eighteen inchesand the tape reel 184 may have an initial diameter of 5 inches.

Also by way of example, the axes of rotation 138 and 238 of the

dereeler assemblies

130 and 230 may be separated by a linear distance of about fourteen inches from the reeler assembly axis 124 when the dereeler assembly is in its first position and separated a distance of about forty inches when in its second position. The axes of

rotation

155 and 255 of the tape dereeler assembly 150 may be spaced 12% inches and 15 inches respectively from the axis of rotation 124 of the reeler assembly 110.

The shoe arm 232 of the

dereeler assemblies

130 and 230 may be ll inches long from its pivot point and the rod 233 on which it is pivoted may be 6% inches forward of a vertical plane through the axis of rotation 138 or 238 of the dereeler assembly and about 10 inches from the axis of rotation of the dereeler assembly.

The paddle 157 may be 5 k inches long from its pivot, which may be spaced 5% inches from the axis of rotation 155 of the tape dereeler assembly 150.

The operation of this embodiment of machine, which is illustrative of further aspects ofthe method of this invention, is as follows.

The

dereeler assemblies

130 and 230 are moved to the positions shown in FIG. 5, and'their retainer caps 139a removed. Prewound reels of foil ribbon 180 are positioned with their side faces against the inward faces of the spools 139 and the retainer caps 139a are replaced and tightened. The rearward dereeler assembly 230 is then moved to its spaced position and the reel supports 134 are pneumatically released by activating the latch releases 239 from the control panel 145. The support 134 of the second dereeler assembly 230 is moved to its outward position and the support 134 of the forward dereeler assembly 130 is moved to its inward position. The welder 161 is moved forward and start leads are welded to the free ends of the ribbons 181. The welder assembly 160 is then moved rearward and the

dereeler assemblies

130 and 230 are pneumatically moved to their position radially adjacent the reeler assembly 1 10. A core structure is then placed in the

jaws

113 and 119 of the reeler assembly 110. The core structure in this case is a stack 190 of .iron L- laminations 191 for use in a small welder transformer. The laminations 191 are merely stacked and not bonded together. The foot of the L" is placed in the rearward chuck 118 and the upper (forward) face of the foot is axially aligned with the forward face of the rearward winding plate 121. The forward chuck 112 is moved forward or rearward to mate suitably with the stack 190. Insulative corner spacers 193 are placed along the long edges of the stack 190 and temporarily held by a strip of pressure-sensitive tape. A pair of coils are then wound by the method hereinafter described. The dereeler assemblies and 230 are then moved to their second, spaced, position pneumatically. It will be seen that the shoes 231 prevent the reels 180 from unwinding and holdthe free ends of the ribbons 181 at a convenient height when the dereeler assemblies are in their second position. The welder 161 is moved to its forward position and finish leads are welded tothe two ribbons 181.

The remainder of the winding of the first pair of coils is completed by'hand and the coils taped around their outer faces. V I

The latch releases 239 are again activated from the control panel and the dereeler support assemblies 134 are moved to the positions shown in FIG. 5. Start leads are welded to the free ends of the ribbons and the welder 161 returned to its rearward position. The

dereeler assemblies

130 and 230 are then moved to their winding positions. The tape reels 184 are shifted on their support shafts 151 by removing the spacers 153 and shifting them to the other sides of the tape reels 184, to the positions shown in FIG. 5. The free end of the insulative tape 186 from each tape reel 184 is then brought under the stack 190 and taped to the end of the ribbon 181, extending about one-half inch beyond the end of the ribbon 181, with a polyester pressure-sensitive tape. The ribbon and insulative tape are positioned on the stack 190 with their ends overlying a spacer 193, and the pressure-sensitive tape is secured to the next successive spacer 193. The start lead 196 of each ribbon 181 is placed through the lead slot in the adjacent winding plate,-to keep it out of the way during the winding of a coil 198.

It will be seen that the leads of the first coil wound from the rearward dereeler assembly 230 may remain in the lead slot of the rearward winding plate, but that the leads of the first coil wound from the forward dereeler assembly 130 must be carefully extended to be axially aligned with the coil, in order to avoid catching them in the second set of coils to be wound.

The motor 126 is then energized and the second pair of coils 198 are wound. When the counter 129 senses that the required number of turns have been wound it disconnects the clutch of the clutch-brake 125 and applies its brake. The

dereeler assemblies

130 and 230 are then moved to their spaced position and the welder 161 moved forward to attach finish leads to the ribbons 181. The ribbons are then cut and the coils completed by turning the stack 190 by hand. The tapes 186 are then cut, leaving an overlap beyond the ends of the ribbons 181. The finished coils are then wrapped with a turn of polyester pressure-sensitive tape. The coils are complete at this point. The core 190 may then be removed. It will be seen that the coils 198 serve to hold the laminations compressed after the core 190 is removed from the

chucks

112 and 119.

The appropriate start and finish leads of the coils are then welded to each other in any conventional manner for joining foil conductors. The remaining leads of the coils are left free for later securement to conductors when the transformer is fully assembled.

If it is desired to wrap additional coils over the coils 1 98, the wrapped stack 1 90 may be set aside until the prewound coils 180 are usedup and reels of ribbon and tape of the proper size for the additional coils are placed on the

dereeler assemblies

120 and 230 and on the tape dereeler assembly 150. Alternatively, a second machine for wrapping these coils may be'provided.

When all of the coils required for a transformer have been wound on the two L-shaped laminated cores used in the transformer, the two sections may be held to- 'gether by conventional means, such as stiffener plates extending across the junction between the two halves and held to the laminations by through-bolts. The entire transformer may then be dipped in varnish and the varnish baked, as is 'well known in the art. The stiffener plates, with theirthrough-bolts, and the varnish hold the laminations making up the foot of the L to each other.

- Illustratively, the length of ribbon between the shoe 231 and the take up point on the coil 198 being formed may be on the order of one to three inches when the prewound re'el 180 is initially placed on the dereeler assembly, and on the order of nine to eleven inches when the prewound reel is depleted. It will be seen that in this embodiment, the sweep of the foot 192 of the core 190 limits the allowed movement of the dereeler assembly 230 toward the reeler assembly 110. It has been found that towards the end of the reel the remarkably true tracking provided'by this machine and method become somewhat less satisfactory, although still within permissiblemanufacturing tolerances. It therefore may be advisable to remove the reels 180 from the dereeler assemblies before they are completely exhausted, and to use the diminished reels for other purposes or in machines, such as that shown in FIGS. l-3, which are relatively unaffected by the reel diameter. The lengths of the tape between the tape dereeler and the coil are on the order of 13 inches and 15 inches respectively and are relatively unchanged as the coils are wound and as the prewound tape reels decrease in diameter.

" It will also be seen that the angle between the ribbon 181 and tape 186 being taken onto the core 190 is at least 90 degrees, so that the tensioning of the foil and the tape are essentially independent of each other, as in'the first embodim'ent. 7

As in the first embodiment, it has been found that,

although the magnetic clutch 137 must be adjusted as the diameter of the prewound ribbon reel decreases, it is unnecessary to provide an automatic feed back system to obtain satisfactory results.

The particular dereeler and tape dereeler assemblies of this embodiment are not particularly adapted to reversing the direction of winding of the core 190 by reversing the direction of rotation of the reeler assembly 110. However, the core 190 may be reversed in the reeler assembly to achieve this result.

A third embodiment of foil coil winding machine is shown in FIG. 6. This embodiment differs from the prior embodiment in that it provides a takeoff point from the prewound ribbon reel 180 which is fixed with respect to the reeler assembly 110, as in the first illustrative embodiment, yet provides a shoe for preventing the reel 180 from unwinding when its dereeler assembly is moved to its second position, spacedfrom the reeler assembly 110.

A roller 391 supported by an arm 392 secured to the base 170 bears against the outer face. of the reel 180 when the dereeler assembly 330 is moved to a first position adjacent the dereeler assembly 1 10. Each modified dereeler assembly 330. has a modified shoe arm 332 supporting a shoe 331. The shoe arm 332 extends below its pivot point and is provided, at its lower end, with a wheel 333 which is engaged by a cam 334 on the base 170. The cam 334 moves the shoe 331 away from the reel 180 and below the roller 391 when the dereeler assembly 330 is moved to its first position. When the dereeler assembly 330 is moved toward its second position, the' shoe arm 332 is released by the cam 334 and is biased into engagement with the outer face of the reel 180 by a spring 335.

It will be seen that if the core being wound has no radially extending leg, or one of moderate length, as shown in. broken lines in FIG. 6, this arrangement allows the takeoff point of the ribbon 181 from the reel 180 to remain the same relative to the reeler assembly 110. The length of ribbon between the reel 180 and a coil being formed is considerably less than the initial diameter of the prewound reel 180. I

Numerous variations in the machine and method of this invention, within the scope of the appended claims, will occur to those skilled in the art in the light of the foregoing disclosure. 1 I

I claim:

1 A machine for simultaneously winding a pair of electrical coils directly onto a rectangular magnetically permeable core, each of said electrical coils including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, said coils being spaced axially from each other, said machine including a driven reeler assembly having a rotating part for winding the coils; a first dereeler assembly for rotatably supporting a prewound'reel of electrically conductive ribbon in a first plane normal to the axis of rotation of said rotating part; a second dereeler assembly for rotatably supporting another prewound reel of electrically conductive ribbon in a second plane parallel to said first .plane and spaced from said first plane; and carriage means for independently supporting said dereeler assemblies for movement of each of said dereeler assemblies in its respective said plane from a first position adjacent said reeler assembly for winding said coil to a second position spaced from said reeler assembly.

2. In a machine for winding a rectangular electrical coil including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, including a driven reeler assembly for winding the coil and a foil dereeler assembly for rotatably supporting a prewound reel of electrically conductive ribbon, the improvement comprising a follower engaging a radially outer face of said prewound reel of conductive ribbon, said follower defining a takeoff point of said conductive ribbon from said reel, said follower being spaced from said reeler assembly and comprising the sole means engaging said conductive ribbon between said prewound reel and'said coil during winding of said coil, thereby defining a length of an unsupported reach of ribbon between said reeler assembly and said follower; means for biasing said prewound reel and said follower into engagement, whereby said follower continues to contact said outer face of said reel as said ribbon is 'dereeled from said prewound reel; and means for'mounting said follower ina fixed position with respect to said reeler assembly, whereby said takeoff point remains fixed with respect to said reeler assembly as said ribbon is dereeled from said prewound reel.

3. In a machine for winding an electrical coil including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, including a driven reeler assembly, having a rotating part for winding the coil, and a foil dereeler assembly for rotatably supporting a prewound reel of electrically conductive ribbon, the improvement comprising carriage assembly means for slidably supporting said foil dereeler assembly for sliding movement from a first position adjacent said reeler assembly, for winding said coil, to a second position, lying in a common plane normal to the axis of rotation of said rotating part with said first position, spaced from said reeler assembly, said dereeler assembly including means for shiftably supporting said dereeler assembly on said carriage assembly means, for shifting said dereeler assembly axially on said carriage assembly means to wind a second coil axially spaced from said first coil.

4. In a machine for winding a rectangular electrical coil including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, including a driven reeler assembly, having a rotating part for winding the coil, and a foil dereeler assembly for rotatably supporting a prewound reel of electrically conductive ribbon, the improvement comprising carriage means for movably supporting said foil dereeler assembly for movement from a first positon adjacent said reeler assembly, for winding said coil, to a second position, lying in a common plane normal to the axis of rotation of said rotating part with said first position, spaced from said reeler assembly; follower means for engaging a radially outer face of said prewound reel of conductive ribbon at least when said reel is in said first position, said follower means defining a takeoff point of said conductive ribbon from said reel, said follower means being spaced from said reeler assembly and comprising the sole means engaging said conductive ribbon betweeen said prewound reel and said coil during winding of said coil, thereby defining a length of an unsupported reach of ribbon between said reeler assembly and said follower means; means biasing said prewound reel and said follower means into engagement, whereby said follower means continues to contact said outer face of said reel as said ribbon is dereeled from said prewound reel; lead connecting means for attaching an electrical lead to a reach of ribbon between said reeler assembly and said dereeler assembly when said dereeler assembly is in said second position, and means rendering said lead connecting means axially movable into said plane normal to said axis of rotation of said rotating part when said dereeler assembly is in said second position and out of said plane when said dereeler assembly is in said first position.

5. In a machine for winding a rectangular electrical coil including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, including a driven reeler assembly, having a rotating part for winding the coil, and a foil dereeler assembly for rotatably supporting a prewound reel of electrically conductive ribbon, the improvement comprising carriage means for movably supporting said foil dereeler assembly for movement from a first position adjacent said reeler assembly, for winding said coil, to a second position, lying in a common plane normal to the axis of rotation of said rotating part with said first position, spaced from said reeler assembly; follower means for engaging a radially outer face of said prewound reel of conductive ribbon at least when said reel is in said first position, said follower means defining a takeoff point of said conductive ribbon from said reel, said follower means being spaced from said reeler assembly and comprising the sole means engaging said conductive ribbon between said prewound reel and said coil during winding of said coil, thereby defining a length of an unsupported reach of ribbon between said reeler assembly and said follower means; means biasing said prewound reel and said follower means into engagement, whereby said follower means continues to contact said outer face of said reel as said ribbon is dereeled from said prewound reel, and electrically variable means in said coil dereeler assembly for impeding the rotation of said prewound reel, said impeding means and said follower comprising the sole tensioning means for said conductive ribbon.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,179, 47; December 18, 1973 Patent No. Dated It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Abstract Add the following:

when a coil is wound except for about a turn and a half, the dereeler assembly is moved to its second positmon, a lead is secured to the foil, the foil is cut and winding of the coil is completed. A second coil or pair of coils may bewound on the same piece by shifting the dereeler assembly axially of the coils previously formed.

Specification Col. 5-, line 1, "shapd" should be "shaped"; I Col. 5, line. '56, "attachement" should be "attachment"; Col. 8, line &5, "11" should be "111" Col. 13, line 5, "120" should be "130";

I Signed and scaled this 6th day of August 1974.

(SEAL) Attestz' MCCOY lylf GIBSON, JR. c. MARSHALLYDANN Attestlng Officer Commissioner of Patents

Claims

1. A machine for simultaneously winding a pair of electrical coils directly onto a rectangular magnetically permeable core, each of said electrical coils including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, said coils being spaced axially from each other, said machine including a driven reeler assembly having a rotating part for winding the coils; a first dereeler assembly for rotatably supporting a prewound reel of electrically conductive ribbon in a first plane normal to the axis of rotation of said rotating part; a second dereeler assembly for rotatably supporting another prewound reel of electrically conductive ribbon in a second plane parallel to said first plane and spaced from said first plane; and carriage means for independently supporting said dereeler assemblies for movement of each of said dereeler assemblies in its respective said plane from a first position adjacent said reeler assembly for winding said coil to a second position spaced from said reeler assembly.

2. In a machine for winding a rectangular electrical coil including a thin ribbon of electrically conductive material convolutely wound in an axially aligned coil, including a driven reeler assembly for winding the coil and a foil dereeler assembly for rotatably supporting a prewound reel of electrically conductive ribbon, the improvement comprising a follower engaging a radially outer face of said prewound reel of conductive ribbon, said follower defining a takeoff point of said conductive ribbon from said reel, said follower being spaced from said reeler assembly and comprising the sole means engaging said conductive ribbon between said prewound reel and said coil during winding of said coil, thereby defining a length of an unsupported reach of ribbon between said reeler assembly and said follower; means for biasing said prewound reel and said follower into engagement, whereby said follower continues to contact said outer face of said reel as said ribbon is dereeled from said prewound reel; and means for mounting said follower in a fixed position with respect to said reeler assembly, whereby said takeoff point remains fixed with respect to said reeler assembly as said ribbon is dereeled from said prewound reel.