JP2008143625A - Traverse drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traverse drum capable of forming a winding package having a lot of winding quantity of thread by suppressing high shoulders and without requiring complicated control. <P>SOLUTION: In the traverse drum 1, a traverse angle θ of a traverse groove 2 is made different at a drum central part and a folding part of both sides. The traverse groove 2A of the drum central part 1A has a small angle θ1, and the traverse groove 2B of the folding part 1B has a large angle θ2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a traverse drum having a traverse groove for traversing a thread on a circumferential surface.

  The angle of the traverse groove of the conventional traverse drum is constant. Since the traverse angle (winding angle) of the yarn around the winding package is determined by the traverse groove angle of the traverse drum, the yarn is wound around the winding package while traversing at a constant traverse angle by the traverse drum. (For example, refer to Patent Document 1).

  At the time of winding, the yarn is turned back at the turn-back portions at both ends of the traverse drum. The traverse speed of the yarn becomes slower as the yarn approaches the turning point of the traverse drum, becomes zero at the turning point of the traverse drum, and becomes faster as the yarn moves away from the turning point of the traverse drum.

  Accordingly, the traverse speed of the yarn is slower at the turn-up portion of the traverse drum than in the central portion of the traverse drum. As a result, at both end portions (ear portions) of the winding package, the time for winding the yarn becomes longer compared to the central portion of the winding package, so that the amount of yarn winding increases and the winding density (hardness) The problem of so-called ear height occurs. When the ear height is generated in the winding package, the unwinding property of the yarn is deteriorated.

In addition, by controlling the peripheral speed of the winding drum that does not have the traverse groove for traversing the yarn on the circumferential surface and the traverse speed of the guide means for the yarn, the traverse angle is adjusted between the center portion and the ear portion of the winding package. There is disclosed a method for forming a winding package that does not cause the problem of deterioration of the unraveling property due to the height difference (for example, see Patent Document 2).
Japanese Utility Model Publication No. 6-10260 JP 2003-192229 A

  If the angle of the traverse groove is small, the problem of the ear height becomes prominent. Therefore, using a conventional traverse drum with a constant traverse groove, the winding amount of the yarn is large and the unwinding property is deteriorated due to the ear height. It is difficult to form a winding package that does not cause this problem.

  Further, in the method of forming a winding package in which the problem of deterioration of the unwinding property due to the height of the ear does not occur by making the twill angle different between the center portion and the ear portion of the winding package, the winding drum that defines the twill angle is used. It is difficult to control the circumferential speed of the yarn and the traverse speed of the yarn guide means.

  Accordingly, the present invention provides a traverse drum capable of forming a winding package with a large amount of yarn wound without reducing the ear height and requiring complicated control in order to solve the above problems. Is an issue.

  In order to achieve the above-mentioned object, the invention according to claim 1 is that the traverse drums for traversing the yarn formed on the circumferential surface have different traverse drums at the central portion and the folded portions at both ends. It is a feature.

  According to the invention according to claim 1 having the above-described configuration, the winding density of the winding package central portion is made different by changing the yarn traversing angle between the drum central portion of the traverse drum and the folded portions at both ends. Further, the winding density of the ear portion can be set to an appropriate range, and a traverse drum capable of forming a winding package having a desired winding density (hardness) over the entire surface can be obtained.

  The invention according to claim 2 is characterized in that an angle of the traverse groove in the central portion is smaller than an angle of the traverse groove in the folded portion.

  According to the invention which concerns on Claim 2 which has said structure, the amount of yarn wound around a winding package can be increased by winding a winding package center part more densely.

  The invention according to claim 3 is characterized in that the leads of the folded portions at both ends are longer than the leads of the central portion.

  According to the invention of claim 3 having the above-described configuration, the traverse speed of the yarn at the turn-back portion becomes faster than the traverse speed of the yarn at the center portion, and the ear height generated at the winding package ear portion is effectively suppressed. can do.

  The invention according to claim 4 is characterized in that the angle of the traverse groove in the central portion is 60% of the angle of the traverse groove in the folded portion.

  According to the invention which concerns on Claim 4 which has said structure, the winding package in which the winding density (hardness) of a winding package center part and the winding density (hardness) of an ear | edge part become substantially equal can be obtained. .

  According to a fifth aspect of the present invention, the central portion includes an intermediate portion adjacent to the folded portion and a central portion located between the intermediate portions, and the central portion, the intermediate portion, and the traversing groove of the folded portion. In the order of the angle of the traverse groove of the central portion, the angle of the traverse groove of the intermediate portion, and the angle of the traverse groove of the folded portion.

  According to the invention according to claim 5 having the above-described configuration, the traverse drum in which the traverse angle is gradually changed so that the entire winding density from the central part of the winding package to the ear part is aligned with the winding shape. Can be obtained.

  According to a sixth aspect of the present invention, the angle of the traverse groove in the central portion is 70% of the angle of the traverse groove in the intermediate portion, and the angle of the traverse groove in the intermediate portion is the traverse of the folded portion. It is characterized by 80% of the angle of the swing groove.

  According to the invention according to claim 6 having the above-described configuration, the traverse angle is gradually changed so that the entire surface from the central part of the winding package to the ear part has substantially the same winding density. A swing drum can be obtained. Further, by using this traverse drum, it is possible to form a winding package in which no traversing occurs, the winding density (hardness) is high, and the winding density (hardness) is more uniform.

  According to the present invention, by using a simple traverse drum in which the traverse angle of the traverse groove is made different between the central portion of the traverse drum and the folded portions at both ends, the winding of the central portion of the winding package is performed. It is possible to form a winding package in which the density and the winding density of the ears at both ends are in an appropriate range. Therefore, using a single traverse drum, the winding density at the center of the winding package can be increased to increase the amount of yarn to be wound, and the winding density at the ears of the winding package can be increased. An increase and an ear height are suppressed, and a winding package having a winding density equivalent to that of the center portion of the winding package can be formed.

  Hereinafter, embodiments of a traverse drum according to the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 is an explanatory view of a traverse drum according to the present invention, (a) is a development view showing the entire traverse groove of the yarn of the traverse drum, and (b) is an illustration of the traverse drum and traverse groove. It is a comparison figure of the density (hardness) of the winding package formed with a traverse drum with a constant angle. FIG. 2 is a development view of a traverse groove of a modified example in which the traverse groove of the folded portion is changed. FIG. 3 is an overall configuration diagram showing an example of a winding unit of an automatic winder provided with a traverse drum according to the present invention.

  As shown in FIG. 3, the automatic winder provided with the traverse drum 1 according to the present invention has the yarn feeding bobbin B placed on the tray T on the lower side of each winding unit U body, The yarn Y wound around the yarn bobbin B is pulled out while being unwound and applied with a predetermined tension via the tension device 10 while being contacted by the traverse drum 1 disposed in the upper winding portion WA. It is wound around a large-diameter winding package P that is driven to rotate.

  Each winding unit U includes a side frame 18, and the cradle 17 that holds the winding bobbin Bf, and the traverse drum 1, the upper thread catching and guiding means 15, which will be described later, and the intermediate pipe 12, are provided in this unit. It is attached to the side frame 18. The side frame 18 is provided with drive means (not shown) such as a drive motor (not shown) for the traverse drum 1 and upper thread catching guide means 15 and controls the winding operation. An electrical component 19 for performing is provided.

  Until the yarn Y unwound from the yarn feeding bobbin B disposed on the lower side of each winding unit main body is wound on the winding package P driven to rotate by the traverse drum 1 disposed on the upper side. In the yarn traveling path, from the yarn feeding side to the winding side, the unwinding assisting device 11, the tension device 10, the intermediate pipe 12 including the yarn clamp 12a and the suction pipe 12b, the yarn joining device 13, the clearer (yarn thick) Various yarn processing devices such as 14) are arranged.

  The unwinding assisting device 11 assists the unwinding of the yarn Y from the yarn supplying bobbin B by lowering the cylindrical body covering the core tube together with the unwinding of the yarn supplying bobbin B. The yarn splicing device 13 splics the lower yarn on the yarn feeding bobbin B side and the upper yarn on the take-up package P side when the yarn is cut by detecting a yarn defect or when the yarn breaks during unwinding. It is. The clearer 14 is for detecting a thickness defect of the yarn Y. Further, the clearer 14 is provided with a cutter 14a for cutting a yarn when a yarn defect is detected.

  In addition, the winding unit WA includes a cradle 17 that holds the winding bobbin Bf and a traverse drum (winding drum) 1 that traverses the yarn Y. The cradle 17 is swingable toward the traverse drum 1, whereby the winding package P wound around the winding bobbin Bf is brought into contact with or separated from the traverse drum 1. Further, the cradle 17 includes a lift-up mechanism 17a that raises the cradle 17 when the yarn breaks and separates the take-up package P from the traverse drum 1, and a take-up package that is held by the cradle 17 at the same time as the cradle 17 is raised. A package brake mechanism 17b for stopping the rotation of P is attached.

  Above and below the yarn splicing device 13, the upper splicing pipe 12, which is a lower yarn catching and guiding means for catching and guiding the lower yarn on the yarn feeding bobbin B side, and the upper yarn on the winding package P side are caught and guided A yarn catching guide means 15 is provided.

  The relay pipe 12 includes a suction pipe 12b and a yarn clamp 12a attached to the tip of the suction pipe 12b. At the time of yarn cutting or yarn breakage, the yarn clamp 12a of the relay pipe 12 catches the lower yarn connected to the clearer cutter 14a and the yarn feeding bobbin B at the position shown in the drawing, and turns from the bottom to the top using the shaft 12c as the rotation axis. Then, the lower thread is guided to the yarn splicing device 13. At the same time, the suction mouth 15a of the upper thread catching and guiding means 15 pivots from the lower position to the upper position around the shaft 15b from the position shown in the figure, catches the upper thread from the winding package P to be reversed, and further centers on the shaft 15b. Then, the upper thread is guided to the yarn splicing device 13 by turning from top to bottom. The yarn splicing device 13 is, for example, an air splicer that splics using a swirling air flow, and the aligned lower yarn and upper yarn are spliced by the yarn splicing device 13.

  As described above, the lower yarn unwound from the yarn feeding bobbin B and the upper yarn on the winding package P side are wound while being spliced to form a winding package P having a predetermined length and a predetermined shape. To do.

  A traverse groove 2 for the yarn Y is provided on the circumferential surface of the traverse drum 1. The yarn Y is wound around the winding package P rotating in contact with the traverse drum 1 while being reciprocated (traversed) at a predetermined traverse angle. Since the yarn Y travels along the traverse groove 2, the traverse angle of the winding package to be formed is regulated by the traverse angle of the yarn when traversing, and the number of winds of the drum and the winding package is defined. Is done. That is, the traverse groove 2 having a predetermined number of winds is provided in the traverse drum 1 in advance, for example, a traverse drum having a wind number of 2.5 winds is usually used.

  However, in the present invention, the traverse angle of the traverse groove 2 is made different between the drum center and the folded portions at both ends.

  Next, referring to FIGS. 1 and 2, the traverse groove 2 of the traverse drum 1 according to the present invention will be described, and the package formed by the traverse drum 1 will be described in detail.

  The traverse drum 1 according to the present invention having the traverse groove of the yarn shown in the development view of FIG. 1A is a traverse drum that winds the yarn Y by bringing the winding package into contact with the circumferential surface of the rotating drum. The traversing angle of the traversing groove differs depending on the angle θ1 of the traversing groove 2A in the drum central portion 1A and the angle θ2 of the traversing groove 2B in the folded portions 1B on both sides. 2 is provided.

  The traverse groove 2 is a traverse groove that is wound with a small traverse angle θ1 and a small traverse angle at the central portion of the winding package corresponding to the drum central portion 1A. It can be formed. Further, the ears of the winding package corresponding to the folded portions 1B on both sides are traverse grooves wound at a larger traverse angle θ2 and a larger traverse angle, and the yarn Y is folded back (turned) faster. It is said. Therefore, it is possible to reduce the winding density (hardness) of the winding package ear portion that originally has a high density.

  The traverse angle θ is an angle that defines the traverse angle of the yarn to be wound when wound on the winding package. If the traverse angle θ1 is small, the lead (drum) that forms a small traverse angle is used. If the traverse distance of the yarn per half rotation) L1 is formed and the traverse angle θ2 is large, the lead L2 that forms a large traverse angle is formed. That is, the traverse speed (traverse speed) with respect to the winding speed (drum circumferential speed) becomes slower at the center of the winding package and faster at the ears of the winding package. Therefore, without using a control device that precisely controls the peripheral speed and traverse speed of the drum, winding can be performed at a high density by winding at a small traverse angle at the center of the winding package. In the ear portion, the winding density (hardness) can be softened by winding at a large twill angle.

  As shown in the figure, the traverse groove 2 provided in the traverse drum 1 advances from the winding start point a in the direction of the arrow D1 to b ′ (b) (corresponding to one rotation), and from b to c ′ ( c) (corresponding to one rotation), c to d '(d) (corresponding to one rotation), and d to e (turning point) (corresponding to 0.5 rotation) The yarn path (outward path) corresponds to a total of 3.5 drum rotations (referred to as a wind number of 3.5). This is a developed view of the traverse groove, so point b and point b ′ are the same point, point c and point c ′, and point d and point d ′ are the same. Because it is a point. Therefore, AL shown in the figure is the traverse total length (the total length of the traverse drum 1), and CL indicates the circumference of the traverse drum 1.

  Since the yarn path from the point a to b ′ corresponds to one revolution of the drum, the yarn path from the point a to h corresponds to the half rotation of the drum, which is the traverse distance of the yarn Y at this time. The distance between i and h is referred to as a lead. Further, the distances between the points hj, jg, gk, kf, fm, and me are each provided with a predetermined lead corresponding to the traverse distance of the yarn Y during the half rotation of the drum. Yes.

  The traverse direction of the lead and the yarn Y is orthogonal to the circumferential direction (rotation direction) of the traverse drum 1.

  Further, the return path reaches from point e to d ′ (d), from d to c ′ (c), from c to b ′ (b), and from b to a ′ (a) (turning point). The route is also a 3.5-wind traverse groove.

  In each of the forward path and the return path, the traverse drum 1 is rotated 3.5 times in the one-way yarn path. Therefore, the traverse drum 1 has a traverse groove 2 of 3.5 wind. It is a traverse drum to prepare. The number of winds is a number indicating the number of rotations (from the drum or the winding package) until the yarn to be wound reaches from one end to the other end of the drum or winding package. The traverse drum 1 is a traverse drum that traverses a predetermined lead.

  As described above, since the yarn path from the point a to b ′ corresponds to one rotation of the drum, the yarn path from the point a to h corresponds to the half rotation of the drum, which is the traverse distance at this time. The distance between points i and h is referred to as lead L2. Further, the distances between points hj, jg, gk, kf, and fm, which are traverse distances corresponding to the half rotation of the drum, are defined as leads L1. Furthermore, the distance between the points me is set as the lead L2.

  That is, the traverse drum 1 includes a traverse groove 2A of a small lead L1 in the drum center portion 1A, and a traverse groove 2B of a large lead L2 in the folded portion 1B on both sides, and the drum center portion 1A and the folded portions on both sides. It is configured to have a predetermined lead ratio in which the leads are different from 1B.

  Next, the relationship between the angle of the traverse groove and the lead will be described with reference to FIG. The lead L1 matches the length of the side jg, and the lead L2 matches the length of the side ih. The ratio of の jbg (θ1) formed by the right triangle jbg and ∠iah (θ2) formed by the right triangle iah is equal to the ratio of the lengths of the side jg (L1) and the side ih (L2). Here, the side jb and the side ia have the same length (semi-circumferential distance: 1/2 CL) and are in a parallel relationship. Further, the side jg and the side ih are orthogonal to the side jb and the side ia, respectively. Therefore, the ratio of the length of the side jg and the side ih, that is, the ratio of the lead L1 and the lead L2, becomes the ratio of ∠jbg (θ1) and ∠iah (θ2).

  From this relationship, when the ratio between the lead L1 and the lead L2 is 3: 5, the relationship between the angles θ1 and θ2 is 3: 5, and the angle θ1 is 60% of the angle θ2.

  The central portion 1A includes an intermediate portion 1AB adjacent to the folded portion 1B and a central portion 1AA located between the intermediate portions 1AB. The central portion 1AA, the intermediate portion 1AB, and the twill of the folded portion 1B. The angle of the swing groove is increased in the order of the angle θ1 of the traverse groove of the central portion 1AA, the angle θ3 of the traverse groove of the intermediate portion 1AB, and the angle θ2 of the traverse groove of the folded portion 1B. The lead L3 may be provided so that the lead ratio from the center portion of the package to the ear portion is 3: 4: 5. With this configuration, the traverse groove has a traverse angle that gradually changes the lead ratio between the lead at the center of the drum and the lead at the folded portion via the lead L3 between the small lead L1 and the large lead L2. Since the speed of traversing the yarn changes smoothly, it is possible to make the winding density more uniform, which is preferable. Further, since the change in the twill angle is small, it is possible to form a winding package with a more uniform shape.

  Since the lead ratio L1; L3: L2 is 3: 4: 5, the angle θ1 of the traverse groove of the central portion 1AA is about 70% of the angle θ3 of the traverse groove of the intermediate portion 1AB. The angle AB3 of the 1AB traverse groove is about 80% of the angle of the traverse groove θ2 of the folded portion 1B.

  As described above, the lead of the drum half rotation is small in the drum central portion, that is, between hj, jj, gg, kf, and fm shown in the figure. The winding package is formed by using the traverse drum 1 having a lead L1 and a lead L2 corresponding to a half rotation of each drum between ih and me of the folded portion. The hardness and winding density of the center part and the ear part can be substantially uniform.

  Further, the lead between the sections h-j connected to i-h of one folded portion is set to L3, which is an intermediate value between L1 and L2, and between the sections m-f linked to me of the other folded portion. Similarly, by setting the lead to the intermediate value L3, the change in the lead ratio between the lead in the center of the drum and the lead in the folded portion, that is, the change in the angle of the traverse groove is reduced, and the winding is performed over the entire winding package. It becomes possible to make the density and hardness more uniform.

  With the traverse drum 1 having the above configuration, it is possible to make the winding density and hardness of the winding package substantially uniform at the center and the ear of the winding package. A winding package having a shape can be formed. However, depending on the type of yarn to be wound, a point where the traversing speed changes, that is, a slightly inner portion of the ear portion of the winding package may be concaved to form an outer shape. At that time, a traverse groove 21 (quick turn groove) (traverse angle θ2 ′, θ2 ″) curved toward the center portion 1A of the traverse drum 1 as shown in FIG. 1B allows the package outer shape to be further flattened by quickly turning back the yarn while retaining the yarn in the recessed portion, and the traverse angle θ2 ′ at which the curved traverse groove 21 changes. , Θ2 ″ is larger than the traverse angle θ1 of the drum central portion 1A, the traverse angles θ2 ′ and θ2 ″ are defined as being greater than the traverse angle θ1 with respect to the present invention.

  As shown in the figure, the traverse groove 2 of the yarn provided in the traverse drum 1 according to the present invention includes a traverse groove 2A provided in the drum center portion 1A and a traverse groove 2B provided in the folded portions 1B on both sides. Has traversing grooves with different traversing angles. Further, the lead L2 of the traverse groove 2B provided in the folded portion 1B on both sides is a traverse groove that is larger than the lead L1 of the traverse groove 2A provided in the drum center portion 1A.

  Therefore, the drum central portion, that is, the central portion of the winding package has a higher density, and the effect of reducing the density difference from the ear portions (both ends of the winding package) that originally increase the winding density of the yarn is obtained. Become. That is, by using the traverse drum 1 according to the present invention, it is possible to form a winding package in which the degree of the ear height is reduced and the hardness distribution is made uniform without performing complicated control.

  In addition, even if the winding density is increased at the central part of the winding package, the winding density of the ear part does not increase extremely, the hardness difference with the central part is reduced, and the degree of the ear height is also reduced. , Can prevent the deterioration of unraveling. For this reason, the winding density of the entire winding package can be increased to increase the winding amount of the yarn.

  FIG. 1B shows a comparison diagram of the density (hardness) of the winding package. The line 31 has the same diameter, circumference, and overall length as the traverse drum 1, and has an traverse groove angle θ defined by a lead that divides the overall length into seven equal parts (corresponding to a 3.5-wind drum). ) Shows the density (hardness) distribution of the winding package. The line 32 has the same diameter, circumference, and overall length as the drum of the present invention, and has a traverse drum angle (2) having a traverse groove angle θ (θ2) defined by a lead (= L2) that divides the overall length into five equal parts. The density (hardness) distribution of the winding package wound by a drum of .5 wind) is shown.

  In the winding method using the conventional traverse drum having a constant traverse groove angle, the winding density of the yarn at the ear portion PB is larger than the winding density at the central portion PA. The hardness of the ear | edge part PB becomes large.

  Line 3 shows the density (hardness) distribution on the surface of the winding package when the traverse drum 1 according to the present invention is used. As is apparent from this figure, even when the winding density at the winding package central portion PA is increased to increase the winding amount to form a hard winding package, the winding density at the ear portion PB of the winding package is The winding density corresponding to a small number of winds (2.5 winds) can be suppressed to the same extent. Therefore, the hardness difference 4 between the central portion PA and the ear portion PB of the winding package can be reduced, and the unraveling property does not deteriorate.

  Further, the winding density at the central portion PA of the winding package can be made larger than the winding density corresponding to a large number of winds (3.5 winds).

  Instead of using a traverse drum having a small angle traverse groove at the center and a large angle traverse groove at both ends, the rotational speed of the winding package and the traverse speed of the yarn It is also possible to control the winding density and hardness of the winding package by performing winding while precisely controlling through a separate control device. However, by using the traverse drum provided with traverse grooves having different traverse angles at the center portion and the folded portions at both ends according to the present invention, it is not necessary to perform complicated control, and the drum is simply rotated at a desired rotational speed. By only continuously rotating, the winding density can be increased, the amount of wound yarn can be increased, the ear height can be prevented from being deteriorated, and a winding package in which the hardness distribution does not change greatly can be formed.

  In addition, when the traverse drum 1 according to the present invention is employed in the winding unit of a spinning machine that winds a plurality of yarns together, a winding package having a high winding density and a small package diameter can be formed. . Therefore, in a double twister that performs twisting by supplying a combined yarn package as a yarn supply package, the diameter of the yarn supply package can be reduced, and the spindle diameter for twisting (diameter of the rotary disk) should be reduced. Is possible. As a result, the size of the double twister facility can be reduced, power consumption can be saved, and energy saving of the double twister can be achieved.

  As described above, according to the present invention, by using the traverse drum having a simple configuration in which the angle of the traverse groove is made different between the center portion of the traverse drum and the folded portions at both ends, A winding package can be formed by setting the winding density of the central part and the winding density of the ear part within an appropriate range. Therefore, the winding density at the center of the winding package is increased to increase the amount of yarn to be wound, and the increase in the winding density at the ears of the winding package is suppressed, and the winding package center and the ears are suppressed. Thus, a traverse drum capable of forming a winding package with a small difference in winding density can be obtained.

It is explanatory drawing of the traverse drum which concerns on this invention, (a) is an expanded view which shows the entire traverse groove of the thread | yarn of a traverse drum, (b) is an angle of this traverse drum and a traverse groove being constant. It is a comparison figure of the density (hardness) of the winding package formed of this traverse drum. It is an expanded view of the modification which changed the traverse groove of the folding | turning part. It is a whole lineblock diagram showing an example of a winding unit of an automatic winder provided with a traverse drum concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traverse drum 1A Drum center part 1B Folding part 2 Traverse groove 2A Traverse groove of drum center part 2B Traverse groove of drum folding part 3 Line (represents the surface hardness of a package)
L1 lead (small)
L2 lead (big)
L3 lead (middle)
U winding unit Y thread

Claims (6)

  A traverse drum characterized in that an angle of a traverse groove for traversing a thread formed on a circumferential surface is different between a central portion and folded portions at both ends.   The traverse drum according to claim 1, wherein an angle of the traverse groove in the central portion is smaller than an angle of the traverse groove in the folded portion.   The traverse drum according to claim 1 or 2, wherein the leads of the folded portions at both ends are longer than the leads of the central portion.   The traverse drum according to claim 2, wherein an angle of the traverse groove in the central portion is 60% of an angle of the traverse groove in the folded portion.   The central portion is composed of an intermediate portion adjacent to the folded portion, and a central portion located between the intermediate portions, and the angle of the traversing groove of the central portion, the intermediate portion, and the folded portion is that of the central portion. The traverse drum according to any one of claims 1 to 3, wherein the traverse drum increases in order of an angle of the traverse groove, an angle of the traverse groove of the intermediate portion, and an angle of the traverse groove of the folded portion.   The angle of the traverse groove in the central portion is 70% of the angle of the traverse groove in the intermediate portion, and the angle of the traverse groove in the intermediate portion is 80% of the angle of the traverse groove in the folded portion. The traverse drum according to claim 5, wherein the traverse drum is provided.

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