US2078228A

US2078228A - Method and apparatus for sheathing cores

Info

Publication number: US2078228A
Application number: US625174A
Authority: US
Inventors: Sidney E Borgeson
Original assignee: General Cable Corp
Current assignee: General Cable Corp
Priority date: 1932-07-27
Filing date: 1932-07-27
Publication date: 1937-04-27
Anticipated expiration: 1954-04-27

Description

April 27, 1937.

s. E. BORGESON 2,078,228

METHOD AND APPARATUS. FOR SHEATHING CORES Filed July-2'7, 1932 6 Sheets-Sheet l Z In W'PHIIUH I lIln U IIMHHHIIH April 27, 1937. s. E. BORGESON METHOD AND APPARATUS FOR SHEATHING CORES 6 Sheets-Sheet 2 Filed July 27, 1932 INVENTOR LSYd/Ycfy 5. 50198.90

April 1937- I s. E. BORGESON, 2,078,228

METHOD AND APPARATUS FOR SHEATHING CORES Filed July 27, 1932 6 Sheets-Sheet 3 INVENTOR 67097: [flu/yawn A ril 27, 1937.

s. E. BORGESON 2,078,228

METHOD AND APPARATUS FOR SHEATHING CORES Filed July 27, 1932 6 Sheets-Sheet 4 ullm INVENTOR (Sid/789' I. 507610 April 27, 1937. s EQBORGESON 2 @78,2Z8

' METHOD AND APPARATUS FOR SHEATHING CORES Filed July 2'7, 1932 6 Sheets-Sheet A riflzv, 193']. E, BO E N' 2,078,228

METHOD AND APPARATUS FOR SHEATHING CORES Filed July 27, 1952 6 Sheets-Sheet 6 lNVENTOR ib fig .5 5049mm till 0 suiatine jacket.

Putented Apr. 3?, will! tilted eittiiitt Sidney lit. liter-genera, meme, N. :1... designer to Gen-- eral iileble @orpcration, New :l'orlr, N. 322, n corporaltien oi New dereey Application July 2?, 393, Serial No. i'ififiJ/lil 22 mature.

This invention relates to e, method and epparatuc for providing a core with e. ilhrous jacket, and more particulerly e, seamless ielted iaclret oi intimately interentanelcd fibers. It is en obiect oi the invention to provide an improved method oi applying a felted fibrous jacket to n core. it else is object of the invention to provide on apperatus tor carrying out the improved method. Other oiiiects and advantages of the invention will appear hereinafter.

it will he eppnrent ironrm the following description' that the new method and apparatus may he used for coating various types of cores, tooth flexible end rigid, solid and hollow, and having varying cross eectlons. Merely for convenience the invention will he described with reference particularly to the insulation of electrical conductors. tin illustrative embodiment of the invention selected merely for descriptive purposes is shown in the accompanying drawings, in which:

Fig. i it e. top plop view oi e. machine for epplylne a ielted insulating covering to electrical conductors;

Fig. 2 it an end elevation of the machine shown in Flex l, ironi the right-hand side of Fig. i;

Fig. 3 is an end elevation of the machine from the leit-hand side oi Fla. 1;

is a view euhstentiaily on the line ill-ll of Fig. 2;

Flu. h on enlarged verticel section substantielly on the line of Fig. 4;

Fly. 6 in it view oi the applicator for applying filters to on electricel conductor, substantially on the line of t le. ti;

i le. l is an elevation oi the separating roll for tearing eptirt the fibers of a decoy strand and for throwing; the separated fillers on to the npplicator;

Fig. t is en elevation of the feeding roll for feeding the fieeey strand to the separating roll;

Fig. t is a longitudinal section through another type of feeding roll: and

Fig. it is 9. partial section to enlarged scale substantiolly on the line ill-it of Fig. 9.

Various methods have been proposed heretoiore for applying a fleecy strand of fibrous materiel to on electrical conductor to form amin- Mony oi the methods of the prior art have not proven practical, either because the method of forming the jacket produces an insulating wall having distinct seams which open up when the conductor is bent, or because of the climculty and cost of especially preparing 911. ill llll the fibrous material in it term suitable for applicetion to the conductor with availeble epparatus.

This invention provides a method and appereitue for forming a compact, seamless felted jaclret about a core, which jeciret comprises fiiilfil'S vari ously and indiscriminately errenged and so interentangled and compacted as to form a unitary fabric wall. The individual fibers comprising the Jacket do not themselves extend in any one general direction, but extend in any end all directions so as to be completely interentengled and uniformly felted. The jacket may he made err tremely thin, or it may he built up uniformly to any practical thiclrnese.

This description refers to the forming of e felted jacket on an electrical conductor. It will be understood, of course, thet there is no limitation, actual or implied, to forming the jacket immediately overlying the conductor itself. The felted jacket may be termed directly on the conductor, or it may be formed over another covering or coverings on the conductor. The fibers may be of any suitable material such, for example, as cotton, asbestos, flax, silk or other materiel. if desired, sepetrate superimposed layers of the same or difierent materials and thicknesses may be formed on the conductor, and these layers may or may not, as desired, he separated by intervening protective or coating materials. sheathed cores and electrical conductors produced by the method and apparatus claimed herein are claimed in my copending divisional epplication Serial No. 128,250, filed February 2'7, 193?.

Referring pemicularly to Figs. 1 to d of the drawings, it will he seen that the housing ll containing the greater part of the mechanism is for convenience mounted upon an angle-bar frame it supported upon standards As may nest be seen in Fig. 2, a drive shaft and pulley, (not shown) driven by any suitable source of power are connected by means of e belt indicated at it which passes from the driving pulley upwardly and over a pulley it, downwardly and under a pulley it, again upwardly and over a pulley ii, and then downwardly to the driving'pulley. For reasons which will appear hereinafter, the driving connection is such that during operation the pulleys it and ll are rotated at a very high speed, while the pulley it desirably is rotated at a lower speed.

The pulley l6 conveniently is utilized through the medium of a variable, speed-reduction driving connection to drive a feeding roll for feeding lit a fieecy strand of fibers from a supply into the machine at a regular predetermined rate. As is best shown in Fig. 4, in the illustrative embodiment the pulley I3 is rigidly secured on one end of a horizontal shaft I8 passing through and rotatably mounted in the lower portion of the housing ll. Referring now to Figs. 3 and 4, secured on the other end of the shaft I8 is a worm l9 meshing with aworm wheel 20 secured on the lower end of a vertical shaft 2| which is rotatably mounted in a bracket 22 projecting from the housing II.

On the vertical shaft 2| is a roller 23 which is keyed to the shaft so as to rotate therewith but which is free to move longitudinally along the shaft. The periphery of the roller 23 frictionally engages the face of a disk 24 secured on one end of a horizontal shaft 25 passing through and rotatably mounted in the housing II. The

disk 24 is resiliently pressed against the roller 23, as by means of a spiral spring 26 surrounding the shaft within the housing H. Also bearing against the face of the disk 24 is a roller 21 mounted on a vertical shaft 23 aligned with and spaced slightly from the end of the shaft 2|. The shaft 28 is rotatably mounted in .a bracket 29 projecting from the housing II. The roller 21 is keyed to the shaft 28 so as to rotate therewith, but is free to move longitudinally along the shaft. It will be apparent thatthe shaft2l acts through the medium of the roller 23 to turn the disk 24, and that rotation of the disk causes the roller 21 and the shaft 28 to turn.

Means are provided for simultaneously sliding the rollers 23 and 21 on the shafts 2| and '28 so as to vary inversely the distances of the rqllers from the center of the disk 24, thereby permitting a wide range of variation in the relative speeds of the two shafta. Conveniently, such means comprises a block 30 having recesses 3| and 32 for receiving the wheels 23 and 21, the block 30 being mounted to slide vertically on a guide 33 mounted in the

brackets

22 and 29.

Vertical adjustment of. the block 30 may be made by means of the vertical screw 34 rotatably mounted in the

brackets

22 and 29, and having screw-threaded engagement with a vertical opening through the block. Conveniently the screw 34 projects upwardly beyond the bracket 29 and is provided with a control'wheel 35. It will be apparent that by turning the wheel 35 the block 30 may be raised or' lowered so as to move-the rollers 23 and 21 over the face of the disk 24 toward and away from the center of the disk, thereby varying the speed of the shaft 28 relative to the speed of the shaft 2| Desirably the variable speed friction clutch arrangement just described is enclosed within a protecting casing 12 secured on the end of the housing II. In the drawings the casing 12 is shown broken away in order to disclose the mechanism within.

The upper end of the vertical shaft 23 projects above the bracket 28 and has secured on its end a worm 36 meshing with a worm wheel 31 which is rigidly secured on one end of a shaft 38 passing through and rotatably mountedin the upper part of the housing As may best be seen in Figs. 5 and 8, secured on the shaft 39 within the casing II is a toothed feedings-011 39. p The feeding roll 39, which normally rotates at .a relatively slow speed, feeds a supply of fibrous material into the machine.

Cenveniently the fibrous material is supplied inlap form wound into a roll 49. The roll 123 may be supported on a center rod 4| having on its ends grooved rollers 42. The rollers 42 rest on the upwardly inclined guides 43 projecting rearwardly from points on the housing ll slightly below the shaft 38. It will be apparent that the weight of the roll of fibrous material will be sufficient to keep the supply of material pressed against the feeding roll 39 at all times, and it will also be apparent that as the feeding roll 39rotates it will remove the lap from the supply roll and feed the fibrous material into the machine. It may be desirable to provide the guides 43 with guard members 44 to aid in keeping the supply roll 4|] in alignment.

As is best shown in Fig. 5, the cover 45 over the feed roll preferably is pressed resiliently toward the feed roll so as to insure uniform feeding of the fibrous material in the machine, as well as to hold the strand while the separating roll teeth tear the fibers of the strand apart. In the illustrative embodiment the cover 45 is provided with a handle 46, and has a limited freedom of movement toward and away from the feed roll along the guide pins 41. Spiral springs 43 surrounding the pins 41 normally press the cover 45 toward the feed roll, such movement being limited by engagement of the handle 46 with the housing I! to prevent actual contact between. the cover 45 and the feed roll 39.

In place of the feeding roll shown in Figs. 5 and 8 it may be desirable in some cases to use a feeding roll having fine axial slots along its surface instead of teeth. Such a roll 39a. is illustrated in Figs. 9 and 10, and merely byway of example the axial slots 3% may be 3 5 inch wide, 1/64 inch deep and spaced 1/64 inch apart.

Referring particularly to Fig. 5, it will be seen that the fieecy strand of fibrous material picked up by the feeding roll 39 from the supply roll 40 is fed into a chamber 54 which contains the separating roll 49. The separating roll is rotatably mounted in the housing ll parallel to the feeding roll 39, and upon one end of the roll axle extending beyond the housing It is secured the pulley i5. During operation of the machine the separating roll is rotated at high speed, and the pins 53', projecting radially from the surface of the separating roll, tear apart the individual fibers of the fieecy strand and project the separated fibers at high speed into the applicator chamber 52;

In order to attain substantially complete separation of the individual fibers comprising the fieecy strand the pins 53 preferably are numerous and somewhat widely spaced, and uniformly distributed over the roll, axially so that the paths of no two pins exactly coincide, and circumferentially so that the separated fibers will form a practically continuous stream. The number of pins will depend upon the degree of separation -of the fibers desired. A suitable arrangement As the separated fibers are thrown off from the separating roll 49 they are projected at high speed into the chamber 52. Mounted in the chamber 52 is an applicator 53 which collects the crank shape.

accuses separated fibers and applies them in a multiplicity of overlying thin layers on the core 55 as the core moves lineally through the chamber. The applicator lib, as shown more'fully in Figs. t and 6, is rotatably mounted in the chamber at, with both of its ends extending beyond the houslug ll. Secured on one end of the applicator is the driving pulley ill, and during operation oi the machine the applicator is rotated at high speed.

l'he applicator has an axial opening through which the core it passes, from right to left in Fig. 1. If desired, the core bl y be coated with an adhesive, as by dipping it in a bath st of adhesive compound, before it enters the applicator. The core is drawn through the applicator by means oi a suitable take-up device as is more clearly shown in Fig. 6, the ends of the applicator desirably are provided with removable guide members lit and bi, conveniently held in place by means oi the nuts at and lit screwthreadedly engaging and clamping the lon gitudinally split ends tilt and iii of the appli-- cater. These guide members are replaceable by other members having different bores to permit the machine being used most advantageously for cores oi different diameters and for i'lbrous jacketc of diflerent thicknesses. Desirably, sealing means indicated at til protect the bearings of the applicator against abrasion from the fibersdn the chamber 52.

Within the chamber til the applicator has one or more ofiset sections, there being three in the illustrative embodiment, which give to it a Desirably these ofiset sections are designed so as to counterbalance each other. hiach of the offset sections is provided with a flat surface to for collecting the separated fibers in the chamber 52, and desirably with means such as a series of closely spaced, curved, spring wire teeth to for conveying the collected fibers to the core and for pressing the fibers on to the core. The rapidlyrotating applicator it collects the fibers on the surface th in the form of a loosely matted ribbon, the fibers so collected extending in any and all directions. As the applicator rotates, this thin ribbon of fibers is drawn toward and wrapped around the core, and since the ap plicator rotates at a very high speed, the fibers will be applied to the core as it passes through the applicator in a multiplicity of overlying thin layers. i

The spring teeth press the thin ribbon of fibers on to the core as it is applied, and this compacting or" the variously and indiscriminately arranged fibers produces in the composite a felted fabric jacket about the core which has substantially uniform characteristics throughout its thickness.

in order to permit access to thcseparating roll and the applicator, the chambers t2 and M in the housing ii desirably are closed by a cover til hinged to the housing at M. For convenience, a handle it is provided, and spring clips ll serve to keep the cover closed during operation.

The operation oi the machine as a whole will now be summarized. The wire or other core bl which is to be coated with fibrous material is moved lineally through the axial opening in the applicator. Gonveniently, the wire is drawn through the machine by means of a power driven take-up device. Thespeed at which the wire is moved through the machine will depend upon the width of the machine, the speed at which the applicator rotates, and the thickness or" the so brous jacket which is to be applied. if desired, the wire may be coated with an adhesive just before it enters the machine.

lhe feeding roll til, the separating roll it and the applicator lit all are rotated. The feeding roll is turning slowly. its driving connection including speed reduction mechanism, and also including means ior accurately varying the speed of the feeding roll. The speed of the feeding roll will depend on the thickness and composition of the fleecy strand of fibrous material being fed into the machine, the speed of the other moving elements of the machine, and the thickness of the fibrous iaclret which is to be applied to the wire. It has been found that for insulating magnet wire in a machine as described the speed of the feeding roll desirably is variable over a. range of from one turn per eighty feet of conductor to one turn per eight feet oi conductor.

The heecy strand of ilbers, for example asbestos, desirably is supplied to the machine in lap form. in a machine of the type specifically disclosed and used for insulating magnet wire the lap may be 5% inches wide, running 200 grains to the yard, and put up in a package 18 inches in diameter. Such a package will weigh approx imaiely 1i) pounds and will cover about some feet oi No. iii magnet wire.

The feeding roll conveys the fibrous strand from the supply package to the separating roll. The separating roll is set with pins desirably oneduarter or an inch long or longer, and the separating roll is rotating at high speed; Desirably, the speed of the separating roll will be such as to separate completely the individual fibers of the strand. Experimental data thus far obtained indicate that the speed in revolutions per minute should be at least iopoo /D where D is the diameter of the roll in inches. The pins of the separating roll tear the fibers of the fleecy strand apart, and the fibers are thrown oil iron: the separating roll by centrifugal force into the applicator chamber.

The high speed of the separating roll is necessary not only to tear the fibers apart, but also to insure that the separated fibers will be thrown oil from the roll. it a few fibers should cling to the teeth, no harm will be done, for these fibers will be carried around and thrown off into the applicator chamber upon the next turn of the separating roll.

Within the applicator chamber, the applicator is turning at high speed, desirably as high as is practical for the structural strength of the applicator, for example about 6,000 revolutions per minute or more. Desirably this speed will be such as to give a pitch or angle of lay between the fibers and the conductor axis of about 65 degrees. The quality of the fibrous covering ap plied to the conductor is about proportional to the angle of lay between the fibers and the condoctor.

The separated fibers which are thrown from the separating roll into the applicator chamber collect on the forward face of the applicator to form a thin, very loosely matted ribbon. The fibers so collected are variously and indiscriminately arranged, and extend in any and all directions. This ribbon is not a true fabric, but there is sumcient cohesion between the fibers as they are pressed together by the rotating applicator so that as the applicator rotates the thin ribbon is wrapped around the conductor. I

The applicator teeth, conveniently of curved spring wire and closely spaced, lay the ribbon of fibers on the conductor and press the ribbon into place; Thus it will be seen that a fibrous wall is built up of a wide, spirally-wrapped, thin ribbon of fibers, the wall having a multiplicity of layers, and the spiral wrapping having a pitch which is very small compared to the width of the ribbon. The ribbon is continuously pressed on to the conductor as it is applied, and the wall which is formed becomes a unitary, seamless felted cov-'- ering in which the identity of the individual layers islost.

It will be noted that the applicator partially obstructs the fiowof fibers into the applicator chamber for a brief interval during each rotation. It has been found that this does not in any way interfere with the operation of the applicator in building up a unitary felted fibrous wall. The applicator is so designed that it tends to scoop up any fibers which may collect on the inner wall of the applicator chamber so that these fibers become a part of the ribbon being fed to the conductor. It will be noted also that as the applicator moves past the opening between the separating and applicator chambers, the separating roll will remove from the outer surface of the applicator any body of fibers which may have accumulatedthereon.

This invention provides a method and apparatus for applying to cores of various sizes and shapes a unitary, seamless jacket of felted fibers. The method and apparatus permit the application ofan extremely thin jacket, or, if desired, the jacket may be built up to any practical thickness. In either case, the character of the jacket is the same, notatably a unitary felted covering having substantially uniform characteristics throughout its thickness.

The foregoing description of certain specific embodiments of the invention is illustrative merely, and is not intended as defining the limits of the invention.

.- I claim:

1. The method of forming a compact felted jacket of, intimately interentangled fibers about a core which comprises moving the core lineally, continuously projecting a thin stream of disconnected fibers toward the moving core in a direction essentially normal to the core, and applying the fibers of the stream to the core in a multiplicity of overlying thin layers.

2. The method of forming a compact felted jacket of intimately interentangled fibers about a core which comprises moving the core lineally, continuously projecting a thin stream of disconnected fibers toward the moving core in a direction essentially normal to the core, applying the fibers of the stream to the core in a multiplicity of overlying thin layers, and individualiy pressing each layer of fibers on the core to form in the composite a unitary seamless jacket having substantially uniform characteristics throughout its thickness.

3. The method of forming a compact felted jacket of intimately interentangled fibers about a core which comprises moving the core lineally, advancing a fieecy strand of fibers toward the moving core, disintegrating the fleecy strand, projecting the disconnected fibers toward the moving core in a continuous thin stream in a direction essentially normal to the core, and applying the fibers of the stream to the core in a multiplicity of overlying thin layers.

4. The method of forming a compact felted jacket of intimately interentangled fibers about a core which comprises moving the core lineally, advancing a fleecy strand of fibers toward the moving core, disintegrating the fleecy strand, projecting the disconnected fibers toward the moving core in a continuous thin stream in a direction essentially normal to the core, applying the fibers of the stream to the core in a multiplicity of overlying thin layers, and compacting each layer of fibers as it is applied to the core to form in the composite a unitary seamless jacket of felted and interentangled fibers in which the layers cannot be individually identified.

5. The method of forming a compact felted jacket of intimately interentangled fibers about a core which comprises moving the core lineally, continuously projecting a thin stream of disconnected fibers toward the moving core in a direction'essentially normal to the core, collecting the fibers adjacent the core in the form of thin loosely matted ribbon, and wrapping the ribbon around the core in a multiplicity of overlying layers.

6. The method of'forming a compact felted jacket of intimately. interentangled fibers about a core which comprises moving the core lineally,-

continuously projecting a thin stream of disconnected fibers toward the moving core in a direction essentially normal to the core, collecting the fibers adjacent the core in the form of .thin loosely matted sections of ribbon, cutting the ribbon into short sections, wrapping the ribbon around the core in a multiplicity of overlying thin layers, and individually pressing each layer of fibers on the core to form in the composite a unitary seamless jacket having substantially uniform characteristics throughout its thickness.

7. The method of forming a compactfelted jacket oi. intimately interentangled fibers about a core which comprises tearing apart the fibers of a fieecy strand, continuously projecting a thin stream oi. the disconnected fibers toward the core in a direction essentially normal to the core, and applying the fibers of the stream to the core in a multiplicity of overlying thin layers.

8. In apparatus for applying a fibrous jacket to a core, the combination of means for moving a core lineally, means for feeding a fieecy strand of fibers toward the moving core, means for tearing the fibers of the strand apart and for throwing them at high speed toward the moving core in a direction essentially normal to the core, and means for collecting the mutually unsupported fibers adjacent the core in a thin loosely matted ribbon and for wrapping the ribbon about the moving core.

9. In apparatus for applying a fibrous jacket to a core, the combination of means for moving a core lineally, means for feeding a fleecy strand of fibers toward the moving core, means for tearing the fibers of the strand apart and for throwing them at high speed toward the moving core in a direction essentially normal to the core, means for collecting the -m'utually.unsupported fibers ina thin loosely matted ribbon and for wrapping the ribbon about the moving core, and means for compacting the fibers into a unitary felted jacket enclosing the moving core.

10. In apparatus for applying a fibrous jacket to a core, the combination of meansfor moving a core lineally, means for applying a coating of adhesive to thecore, means for feeding a fleecy no to a core, means for applying separated fibers to aovaaae hi strand of fibers toward the moving core, means for tearing the fibers of the strand apart and for throwing them at high speed toward the moving core in a direction essentially normal to the core, and means for collecting the mutually unsupported fibers in a thin loosely matted ribbon and for wrapping the ribbon about the moving core.

11. In apparatus for applying a fibrous jacket to a core, the combination of means for moving a core lineally, means for feeding a fleecy strand of fibers toward the moving core, means for tearing the fibers of the strand apart and for throw ing them at high speed toward the moving core in a direction essentially normal to the core, and means for collecting the mutually unsupported fibers and applying them in a multiplicity of overlying thin layers on the core.

12. In apparatus for applying a fibrous jacket to a core, the combination of means for moving a core lineallyfmeans for feeding a fleecy strand of fibers toward the moving core; means for tear:- ing the fibers of the strand apart and for throw ing them at high speed toward the moving core mutually unsupported fibers and applying them in a multiplicity of overlying thin layers on the core.

14. In apparatus for applying a fibrous jacket a core to form a unitary seamless felted jacket, which means comprises a stationary casing, a rotatable member mounted within said casing and having an axial opening for passage of a core, means for projecting separated fibers into said casing in a direction essentially normal to the core passage, and an eccentric section on said rotatable member for collecting separated fibers in the form of a thin loosely matted ribbon and 5% for wrapping the ribbon about the core in a multiplicity of overlying layers.

15. In apparatus for applying a fibrous jacket to a core, means for applying separated fibers to a core to form a unitary seamless felted jacket,

5 which means comprises a stationary casing, a

in the form or a thin loosely matted ribbon and for wrapping the ribbon about the core in a multiplicity of overlying layers, and means on said rotatable member for pressing the ribbon on the core as it is applied thereto to compact the fibers into a unitary seamless jacket.

16. In an apparatus for applying a fibrous cov ering to a core, means for conveying separated fibers in a thin stream to the core, a stationary housing surrounding the core for collecting the fibers, and rotatable means within the housing for wrapping the fibers about the core.

17. In an apparatus for applying a fibrous covering to a core, a stationary chamber partly surrounding the core for collecting fibers, means for conveying separated fibers into the chamber, and means within the collecting chamber for wrapping the fibers about the core.

18. In an apparatus for applying a fibrous covering to a core, a stationary chamber having openings for the linear passage of a core through the chamber and an opening parallel to the core axis for admitting fibers, means for conveying separated fibers into the chamber, and means within the chamber for wrapping the fibers about the core.

19. In an apparatus for applying a fibrous cov= ering to av core, a stationary collecting chamber about the core, rotatable means mounted within applying section including means resiliently engaging the core, and means for conveying fibers to the applying means.

21. In an apparatus for applying a fibrous coyering to a core, means for moving a fieecy strand of fibers toward the core, means for separating the fibers of the strand and ior conveying the separated fibers in a thin stream toward the core, a housing surrounding the core for collecting the fibers, and rotatable means within the housing for repeatedly cutting across the stream of fibers and for applying the fibers to the core in a multiplicity of thin overlying layers.

22. In an apparatus for applying a fibrous coyering to a core, means for conveying separated fibers in a thin stream toward the core, a stationary housing surrounding the core for collecting the fibers, and rotatable means within the housing for picking up the mutually unsupported fibers in the form of a thin ribbon and wrapping the ribbon around the core in overlying layers.

smnnv E. BORGESON.