US3685329A

US3685329A - Apparatus for helically corrugating flexible tubular metal foil ducts

Info

Publication number: US3685329A
Application number: US125677A
Authority: US
Inventors: Charles William Amos; Maynard Dale Johnson; John Jacob Dieckmann
Original assignee: Dunham Bush Inc
Current assignee: HYDROTHEM Inc A DE CORP
Priority date: 1971-03-18
Filing date: 1971-03-18
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22

Abstract

A fluted mandrel rotates within a flexible, axially moving, metal foil, corrugated tubular duct as it is being continuously formed, downstream of the corrugation forming dies to remove burrs from the internal surfaces created during wrapping of the foil strips to form the tube and corrugation of the same to lower resistance to air flow through the tubing during usage.

Description

United States Patent Amos et al.

1 Aug. 22, 1972 154] APPARATUS FOR HELICALLY CORRUGATING FLEXIBLE TUBULAR METAL FOIL DUCTS [72] Inventors: Charles William Amos; Maynard Dale Johnson, both of Harrisonburg; John Jacob Dieckmann, Rockingham County, all of Va.

[73] Assignee: Dunham-Bush, Inc., l-larrisonburg,

22 Filed: March 18, 1971 21 Appl.No.: 125,677

[52] US. Cl ..72/129, 72/135 [51] Int. Cl....; ..B21C 37/12 [58] Field of Search ..72/135, 41, 45,43, 44,70, 72/71,129,130,137,138,141, 340, 341,

' [56] References Cited UNITED STATES PATENTS 2,351,710 6/1944 Sanders ..72/41 2,688,906 9/1954 Dokopil ..156/207 X 3,528,159 9/1970 Miles ..29/423 Primary Examiner-Richard .1. Herbst Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A fluted mandrel rotates within a flexible, axially moving, metal foil, corrugated tubular duct as it is being continuously formed, downstream of the corrugation forming dies to remove burrs from the internal surfaces created during wrapping of the foil strips to form the tube and corrugation of the same to lower resistance to air flow through the tubing during usage.

5 Claims, 3 Drawing Figures APPARATUS FOR HELICALLY CORRUGATING FLEXIBLE TUBULAR METAL FOIL DUCTS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to machines for automatically forming flexible tubular ducts by helically overlapping metal foil strips and more particularly to an improved apparatus for forming the same in which the tubing is corrugated without materially increasing its resistance to the passage of air flowing through the same during usage.

2. Description of the Prior Art Machines have been developed for the production of helically corrugated flexible tubular metal ducts in long continuous lengths, which are substantially air tight for use in air conditioning installations. Such a machine is set forth in US. Pat. No. 3,528,159 to George N. Miles and entitled Method of Making Helically Corrugated Flexible Tubular Duct of Metal Foil and for Insulating the Same.

In the referred to patent, the corrugated, flexible duct is formed by first helically wrapping a strip of friction reducing material, such as a paper tape on the exterior of a fixed hollow forming mandrel which defines a temporary inner surface of the duct wall. Secondly, a plurality of over-lapping strips of metal foil are helically wrapped upon the friction-reducing wrapping to define a duct wall having multiple plies of metal foil. Thereafter, the formed tube of metal foil and underlying paper is moved axially through simultaneously revolving inner and outer, mating screw-threaded dies to create helical corrugations while at the same time continuously feeding the duct downstream by the screw action of the revolving dies. One function of the inner paper lining is to reduce the friction between the formed tube and the corrugating die. Also, oil is sprayed onto the outer surface of the helically wrapped metal foil tube just upstream of the corrugating dies to further reduce the friction existing between the tubing and the driven corrugating dies.

While the initial wrapping of the mandrel upstream of the corrugating dies with paper acts to materially reduce the friction between the multi-ply metal tube and the inner corrugating die during manufacture, it is necessary to remove the inner paper layer of the tube downstream of the corrugating means to produce a wholly metal corrugated tube useful in passing air under pressure and at high velocity and such helically corrugated metal foil tubes have great application to the air conditioning industry.

In the Miles patent, means are provided for unpeeling the helically wrapped paper layer from the internal surface of the multi-ply metal foil tubing downstream of the corrugating dies and, in fact, downstream of a stationary holding assembly which prevents the tube from twisting due to the effects of the corrugating dies. The holding assembly lies intermediate of the corrugating dies and corrugation stretching means in the form of a plurality of reciprocating fingers which act to stretch the tube corrugations at the output end of the machine. ln the Miles patent, in order to prevent the paper stripping means from stripping the paper prior to passage beyond the holding assembly and the corrugating stretching means, a magnetic sensor is employed which senses the change in reluctance of the magnetic circuit due to the presence or absence of the paper and the magnetic sensing means is located just downstream of the stretching assembly. This achieves periodic energization of a friction clutch controlled paper pulling apparatus at the extreme upstream end of the machine associated with a windlass mechanism, with the removed paper strip falling freely into a waste area at the front end of the machine.

While satisfactory, use of the paper itself increases the cost of the production of the flexible, corrugated metal foil duct, adds to the complexity of the machine and increases maintenance time and the propensity for machine shutdown due to the necessity for adjustment of associated elements or replacement due to' their failure.

In an attempt to eliminate the necessity for preliminary formation of an inner paper lining for the multiply metal foil duct prior to corrugating, the initial helical wrapping of the paper foil to the mandrel upstream of the corrugating dies was eliminated but this resulted in an increase in friction between the helical metal foil duct and the inner rotating corrugating die and, more importantly, caused the formation of burrs on the internal surfaces of the corrugated metal foil tubular duct.

SUMMARY OF THE INVENTION The present invention is directed to an improved machine for making helically corrugated, metal foil flexible tubular ducts in which the need for initially wrapping the duct-forming mandrel upstream of the corrugating die with a paper lining, is eliminated. Further, the improved machine of the present invention allows a flexible tubular duct to be formed without this preliminary step and without materially increasing the friction between the rotating corrugating dies and the duct and allows the tubular duct to be completed without internal burrs sufficient to materially affect the static pressure of fluids passing through the same during usage.

Specifically, the present invention is directed to an improved machine for forming a flexible tubular duct having a helically corrugated metal foil wall of the type employing a hollow mandrel upon which is wrapped a plurality of strips of metal foil to define a multiple ply duct wall. Inner and outer corrugating dies downstream of the hollow mandrel embrace the helically wound metal foil duct to corrugate the same while automatically feeding the duct axially. The machine further includes means exterior of the corrugations for axially spacing the corrugations downstream of the corrugated forming dies. Lubricating oil is sprayed onto the inner and outer surfaces of the helically wound multi-ply metal foil duct upstream of the corrugating die for reducing friction during corrugating. A mandrel is rotated internally of the duct downstream of the corrugating means, the rotating mandrel being fluted to define longitudinal cutting edges capable of deburring the internal surfaces of the corrugated metal foil tubular duct during continuous production of the duct and axial movement of the duct about the rotating mandrel.

Preferably, the rotating mandrel includes a plurality of circumferentially distinct flexible fingers defining the fluted portion of the mandrel and carries an axially threaded bore a portion of its length which threadably receives a tapered adjusting screw permitting limited fingers to vary first helically wrapped, and is preferably coupled to a.

drive motor through a suitable gear reduction, speed control mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partially broken away, of the improved apparatus of the present invention.

FIG. 2 is a sectional, elevational view of a portion of the apparatus shown in FIG. 1.

FIG. 3 is a section of the rotating mandrel forming a major element of the improved apparatus of the present invention, taken about lines A-A of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the apparatus of the present invention constitutes a machine comprising a metal mainframe 1 which is U-shaped in configuration and incorporates a pair of upright support members 2 and 3 which encloses portions of the drive mechanism and supports in particular a fixed, hollow mandrel assembly identified generally at 4. A main drive motor 6 rests on the floor of the building housing the machine and through a belt and pulley drive arrangement, rotates a counter shaft 7 which is in turn supported by bearings 8 at opposite ends of the machine main frame 1. The counter shaft 7 carries two sprockets 9 and 11 at opposite ends of the frame 1 with a change-gear box 12 providing a driving connection between the counter shaft 7 and a stub shaft 16 which in turn drives a sprocket in the opposite direction to that of sprockets 9 and 11.

Sprocket chains

13, 14 and 15 respectively coupled to sprockets 9, 10 and 11 engage

respective sprockets

17, 18 and 19 carried by the mandrel assembly 4. By shifting gears in box 12 the speed of rotation of sprocket 18 may be varied relative to the speed of rotation of

sprockets

17 and 19. A drive path, including sprocket 9, chain 13 and driven sprocket 17, rotates a hollow shaft 20 which is coaxially positioned within a fixed, hollow mandrel 33 forming a part of the mandrel assembly 4. The driven hollow shaft 20 is attached by a disengagable positive drive connection 22 to the inner helical screw-threaded, hollow corrugating die 23, FIG. 2, in such a manner that die 23 is rotated due to the connection 22 being formed by projecting dogs on the rear face of the inner die 23 which engage in recesses in the end of the hollow drive shaft.

ln mesh with the inner die 23 is an outer helical screw-threaded corrugating die 24, which seats in a socket 25 within hub 26 of driven sprocket 19. The outer die 24 is keyed to the hub 26 to be positively driven by the drive path including driving sprocket l1, sprocket chain 15, driven sprocket 19 and hub 26. The

sprockets 9 and 11 are of thesame diameter as are sprockets l7 and 19, thus the inner and outer corrugating dies 23 and 24 rotate at exactly the same speed to helically corrugate the tabular wall 27 of a multi-ply metal foil duct 28, FIG. 1, while feeding the duct from right to left by. the screw action of the mating dies as indicated by arrow 30.

The dies 23 and 24 are readily removable by pulling them from right to left, FIG. 1, thus simultaneously disengaging them respectively from shaft 20 and from hub 26. After the dies 23 and 24 are removed, they may be separated from each other by the simple act of unscrewing one from the other.

As described to this point, the apparatus is identical to that of the Miles patent and to form the metal foil duct, a spool assembly 32 is rotated by the driven sprocket l8 joumaled by the main frame 1 about the hollow, fixed forming mandrel 33, which in turn is concentric with and surrounds the rotating hollow shaft 20. A pair of strips of metal foil 34 and 36, preferably of aluminum and having a thickness on the order of 0.003

inches, are fed from respective spools carried by the spool assembly 32 to form, in terms of a left hand helical wrap, the duct wall 27 in the identical manner to that of the referred to patent. As readily indicated by the relative size of the sprockets l0 and 18, FIG. 1, the spool assembly 32 rotates at about one-half the r. p. m. of dies 23 and 24, the relative rate being determined by the pitch at which the foil strips 34 and 36 are applied.

Unlike the prior art machine, in order to reduce friction between the outer die 24, the inner die 23 and the multi-ply foil tube sandwiched therebetween and corrugated by rotation of both dies, an oil spray mist applied by an air driven oil atomizer spray nozzle 40, FIG. 1, exterior of the mandrel assembly 4 and upstream of the dies 23 and 24, and a similar device (not shown), interiorly of mandrel 33, allows the inner and outer surfaces of the wall 27 to be lubricated sufficiently to greatly reduce the friction between the dies and the aluminum wall 27. During operation, dies 23 and 24 corrugate the wall 27 with closely packed corrugations in a right hand helix.

In order to prevent the tubular wall 27 of duct 28 from turning, a stationary holding assembly 42 is employed downstream of the corrugating dies 23 and 24 which is modified slightly from that of the prior art patent. The holding assembly, in similar fashion to the prior patent, includes a pair of concave cylindrical gripping jaw members 43 which are removably connected to a pair of arms 44 pivotably attached at 45 to a mounting plate 46 which is in turn secured by bolts 47 to support 2 of frame 1.

A tension spring 48 positioned between arms 44 urges the arms toward each other to press the jaw members 43 against the outside of the tubular wall '27. Means (not shown) allow the arms 44 to be swung outwardly allowing the jaw members 43 to be readily removed in the identical fashion to the prior art patent.

Unlike the prior art patent, the holding assembly 42 includes a non-adjustable inner, stationary arbor or mandrel 52 whose circumference may or may not be longitudinally fluted depending upon the necessity to reduce friction between the stationary components of the machine and the helically moving duct 28 downstream of the corrugating dies. As illustrated, the

arbor 52 comprises a hollow cylindrical mandrel 204 which has a threaded axial bore section 53 allowing it to threadily engage the outer end of a hollow stationary shaft 58 which is coaxial with the hollow rotating shaft 20, the rotating shaft being concentric to the fixed shaft 58. Shaft 58 extends towards the front of the machine, is joumaled by the right hand upright support 2 of the main frame 1 and is fixed to the frame by a spider assembly 54 which replaces the windlass of the prior art machine. The diameter of the fixed mandrel 204 is generally the same as the desired internal diameter of the helically corrugated duct 28 and the frictional restraint provided by the gripping jaw members on the exterior surface is sufficient to allow feed of the tubular duct 28 axially in the direction of arrow 30 but prevents rotation of the same during corrugating.

In a similar manner to the prior art machine, an axially slidable, reciprocating slide assembly 60 is provided on the left hand end of the machine, FIG. 1, with the assembly 60 being mounted on a pair of longitudinally extending slideways or rods 61 fixed t0 the main frame 1 by means of plate 46. To effect reciprocation of assembly 60, a push rod 62 is pivotably attached to the arm of lever 63, the lever being pivoted on the same mounting plate 46 and being coupled at another arm to a connecting rod 64 by adjustable coupling means 65. In turn, the connecting rod 64 is carried by revolving crank 66 at the outboard end of counter shaft 7. Adjusting connection 65 varies the length of the stroke of the reciprocating assembly 60.

The assembly 60 includes a pair of side plates 68, to each of which is attached, a plurality of longitudinally spaced, spring rachet fingers 70 which converge in a downstream direction with duct wall 27. The inner ends 71 of the spring fingers are bent inwardly and at generally right angles to the axis of duct 28 and preferably'shaped with a concave end surface adapted to engage the outside of the duct wall 27 in the valleys between successive convolutions as shown in FIG. 2. The outer ends 73 of the spring fingers are secured to the side plate 68 by bolt 74. With this arrangement, when the slide assembly 60 moves downstream, that is, from right to left, FIG. 1, the finger ends 71 engage in the valleys and pull the localized region of the duct axially to space the convolutions of the corrugated duct further apart. When the slide assembly 60 moves on reverse motion, toward the right, the spring fingers 70 flex outwardly so that their ends 71 slide over the ridges of the convolutions. The stretching, hitch feed action of the multiple fingers 70 occurs at an average feed rate greater than the screw feed rate of dies 23 and 24 so that the net effect is to stretch open the corrugations formed by the dies. For access to the formed tubular duct 28, the slide assembly 60 may be opened up quickly by rotation of latch 77 from the horizontal position shown, FIG. 1, thus allowing the side plate 68 to be swung outwardly about hingepins 78.

The present invention is directed particularly to a rotating mandrel assembly 200 which is in general lonmary function of deburring the internal surfaces of the duct so as to greatly reduce the friction efiects of the confining duct on a moving air stream within the duct during normal usage in the refrigeration and other arts.

Specifically, the present machine carries a third rotatable, solid shaft 203 about which fixed hollow shaft 58, rotating hollow shaft 20 and fixed hollow mandrel 33 are concentrically positioned in that order. The rotating shaft 203 extends the full length of the machine and is threadably coupled, at its downstream end, to a cylindrical mandrel 202. At its upstream end, the shaft 203 is joumaled within spider assembly 54, the extreme outer end protruding outwardly from the spider and is coupled to a sprocket wheel 205. An auxiliary motor 208 mounted on a fixed support 210 which, in turn, is coupled to spider 54 has its output shaft 211 coupled to a gear box 208. ln turn, the gear box has an output shaft 212 carrying a driving sprocket 207, the driving sprocket being coupled to driven sprocket 205 via endless drive chain 206.

While the portion of the rotating mandrel 202 which lies interior of the reciprocating stretching assembly has a smooth unbroken peripheral surface and acts as a full circumferential support for the formed tubular duct 28 in the area of the stretching mechanism, the mandrel terminates at its downstream end in a fluted portion 202. The fluted portion is defined by slightly flexible fingers 213 spaced circumferentially at 90 and being separated from each other by longitudinal slots 214 which extend the length of the fluted portion 202'. This end of the mandrel 202 is tapped and threaded at 215 and receives an adjustment screw 201 which is provided with a slightly tapered thread. Thus, by rotation of the adjustment screw 201, the individual fingers 213 are spread radially causing longitudinalcutting edges 216 of the rotating mandrel 202 to contact the interior surfaces of the corrugated tubular duct 28. The speed of the rotating mandrel 202 may be readily varied by change speed box 208 and/or by the selection in size of the driving sprocket 207 and the driven sprocket 205, however, it is preferable that the rotating mandrel 202 be driven at a speed in excess of and rotate in the opposite direction to the corrugating dies to insure maximum deburring of the interior surfaces of the formed multi-ply metal foil corrugated tubular duct 28.

The operation of the machine is apparent from the previous description. However, briefly, the machine is quite capable of producing a corrugated all-metal duct 28 at a rate of 12 lineal feet per minute with the corrugating dies 23 and 24 revolving at approximately 300 r. p. m. and the spool assembly revolving at a rate of approximately one-half the same. Aluminum foil strips of 0.003 inches and a width of two and one-half to three inches produces a finished corrugate duct having a wall thickness of approximately 0.08 inches including the depth of the corrugations with the duct being substan- 42. After the formed, corrugated tubular duct 28 slides between outer clamping member 43 and inner, fixed mandrel 204, the duct moves axially over the smooth circumferential surface of the upstream portion of the rotating mandrel 202. At this point, the flexible fingers 70 of the reciprocating stretching assembly 60 engage the outer surface of the duct and stretch the individual convolutions, since reciprocation from right to left occurs at a greater speed than that of the moving duct as expressed by dies 23 and 24. In turn, during reciprocation from left to right, the flexible fingers move over the ridges and again fall into other valleys of the continuously moving duct 28. During the rotation of the mandrel 202, the fluted portion 202' and in particular the longitudinal cutting edges 216 of the individual fingers 213 rotate at relatively high speed with respect to the nonrotating duct to deburr the interior surfaces caused by wrapping and corrugating of the multi-ply metal foil strips 34 and 36. The finished duct 28 leaves the machine in a fashion capable of being used with or without the addition of insulation material allowing the manufacture of long lengths of insulated or noninsulated duct at minimum expense characterized by a smooth inner duct surface with low static friction to the gases moving under pressure and at relatively high velocity through the same during subsequent usage.

What is claimed is:

1. In a machine for forming a flexible tubular duct having a helically corrugated multi-ply metal foil wall including a hollow foil wrapping mandrel, means for helically wrapping a plurality of strips of metal foil about said hollow mandrel in overlapping fashion to define a multiple-ply duct wall, relatively rotating inner and outer dies embracing said helically wound duct downstream of said wrapping means for corrugating the same and feeding the duct axially, the improvement comprising:

a mandrel positioned internally of said corrugated tu bular duct, downstream of said inner and outer dies,

means for rotating said mandrel, and

longitudinal cutting edges carried by said rotating mandrel in contact with the interior surfaces of said corrugated duct for removing any burrs formed by passage of said multi-ply metal foil duct through said corrugating dies.

2. The machine as claimed in claim 1, wherein said machine further comprises means downstream of said corrugating ,dies operatively engaging the exterior of said corrugated duct for axially spacing said corrugations and said rotating mandrel includes a peripheral surface portion radially aligned with said exterior corrugating spacing means and in contact with the duct interior for supporting said duct during expansion of said corrugations by said axial spacing means.

3. The machine as claimed in claim 1, wherein said rotating mandrel includes: a plurality of integral, circumferentially spaced, fingers defining the fluted portion of said mandrel with edges of said fingers constituting the longitudinal cutting edges of said mandrel and means carried by said mandrel allowing limited radial adjustment of said flexible fingers to insure contactof said cutting edges with the duct interior and maximum de 'n of same.

i flie mac ne as claimed in claim 2, wherein said rotating mandrel upstream portion which is radially aligned with said corrugations convolution spacing means is peripherally smooth and unbroken, and said fluted downstream portion is defined by circumferentially spaced flexible fingers formed by longitudinal flute recesses, longitudinal slots at the bottom of said recesses, said rotating mandrel including an axial bore extending from the downstream end a length on the order of that of said flute recesses and an adjustment screw carried by said threaded bore and having axially tapered thread portion whereby threading of the screw deeper within the threaded bore of the mandrel forces the flexible fingers outwardly to increase the radial position of the longitudinal cutting edges and insure contact with the same with the formed tubular duct.

5. The machine as claimed in claim 1, wherein: said hollow foil wrapping mandrel is stationary and concentrically carries first, second and third shafts, said first shaft :is hollow, is mounted for rotation and is fixedly coupled to said inner die, said second shaft is hollow, is coaxially fixed within said first shaft and extends axially downstream beyond said inner and outer dies, said machine further includes: means rotating said outer die at the same speed as said inner die to corrugate said tube, a fixed hollow stationary mandrel coupled to said second shaft having a diameter on the order of that of said corrugated duct and positioned downstream of the rotating die in contact with the interior wall of said tube, clamping means-axially aligned with said fixed mandrel and frictionally gripping the outside of said corrugated tubular duct to prevent rotation of said duct during corrugation by said dies, means for supporting said third shaft for rotation within said fixed hollow second shaft with one end coupled to said rotating mandrel downstream of said fixed mandrel and said clamping means and the other end extending axially beyond said fixed wrapping mandrel and being coupled to a drive motor for effecting rotation of said third shaft and the rotating mandrel coupled thereto.

Claims

1. In a machine for forming a flexible tubular duct having a helically corrugated multi-ply metal foil wall including a hollow foil wrapping mandrel, means for helically wrapping a plurality of strips of metal foil about said hollow mandrel in overlapping fashion to define a multiple-ply duct wall, relatively rotating inner and outer dies embracing said helically wound duct downstream of said wrapping means for corrugating the same and feeding the duct axially, the improvement comprising: a mandrel positioned internally of said corrugated tubular duct, downstream of said inner and outer dies, means for rotating said mandrel, and longitudinal cutting edges carried by said rotating mandrel in contact with the interior surfaces of said corrugated duct for removing any burrs formed by passage of said multi-ply metal foil duct through said corrugating dies.

2. The machine as claimed in claim 1, wherein said machine further comprises means downstream of said corrugating dies operatively engaging the exterior of said corrugated duct for axially spacing said corrugations and said rotating mandrel includes a peripheral surface portion radially alIgned with said exterior corrugating spacing means and in contact with the duct interior for supporting said duct during expansion of said corrugations by said axial spacing means.

3. The machine as claimed in claim 1, wherein said rotating mandrel includes: a plurality of integral, circumferentially spaced, fingers defining the fluted portion of said mandrel with edges of said fingers constituting the longitudinal cutting edges of said mandrel and means carried by said mandrel allowing limited radial adjustment of said flexible fingers to insure contact of said cutting edges with the duct interior and maximum deburring of the same.

4. The machine as claimed in claim 2, wherein said rotating mandrel upstream portion which is radially aligned with said corrugations convolution spacing means is peripherally smooth and unbroken, and said fluted downstream portion is defined by circumferentially spaced flexible fingers formed by longitudinal flute recesses, longitudinal slots at the bottom of said recesses, said rotating mandrel including an axial bore extending from the downstream end a length on the order of that of said flute recesses and an adjustment screw carried by said threaded bore and having axially tapered thread portion whereby threading of the screw deeper within the threaded bore of the mandrel forces the flexible fingers outwardly to increase the radial position of the longitudinal cutting edges and insure contact with the same with the formed tubular duct.

5. The machine as claimed in claim 1, wherein: said hollow foil wrapping mandrel is stationary and concentrically carries first, second and third shafts, said first shaft is hollow, is mounted for rotation and is fixedly coupled to said inner die, said second shaft is hollow, is coaxially fixed within said first shaft and extends axially downstream beyond said inner and outer dies, said machine further includes: means rotating said outer die at the same speed as said inner die to corrugate said tube, a fixed hollow stationary mandrel coupled to said second shaft having a diameter on the order of that of said corrugated duct and positioned downstream of the rotating die in contact with the interior wall of said tube, clamping means axially aligned with said fixed mandrel and frictionally gripping the outside of said corrugated tubular duct to prevent rotation of said duct during corrugation by said dies, means for supporting said third shaft for rotation within said fixed hollow second shaft with one end coupled to said rotating mandrel downstream of said fixed mandrel and said clamping means and the other end extending axially beyond said fixed wrapping mandrel and being coupled to a drive motor for effecting rotation of said third shaft and the rotating mandrel coupled thereto.