Yarn winding apparatus, take-up winder using yarn winding apparatus, yarn winding method and taper end package

Abstract

 The present invention provides a yarn winding apparatus configured to allow monofilaments to be cross-wound to form a taper end package. A yarn winding apparatus 1 includes bobbin holders 3 each configured to support a plurality of take-up tubes 2 around which respective plural supplied yarns Y are wound, a plurality of belt type traverse devices 5 each including a yarn guide 4 configured to be able to catch the corresponding yarn Y, the traverse device 5 reciprocating the yarn guide 4 to traverse the yarn Y with respect to the corresponding take-up tube 2, and a contact roller 11 provided between the set of the plurality of traverse devices 5 and the bobbin holders 3 and pressed against packages Q formed on the respective take-up tubes 2. Each of the belt type traverse devices 5 is configured to be able to change the reciprocation range of reciprocating motion of the yarn guide 4.

Description

Field of the Invention

[0001] The present invention relates to a yarn winding apparatus, a take-up winder that uses the yarn winding apparatus, a yarn winding method, and a take-up winding method that uses the yarn winding method, and a taper end package.

Background of the Invention

[0002] As a technique of this kind, the Unexamined Japanese Patent Application Publication (Tokkai-Hei) No. 5-24740 discloses a yarn traversing device including a first traverse blade and a second traverse blade both provided for each of a plurality of take-up tubes arranged in an axial direction so that yarn can be wound around each of the take-up tubes. The first and second traverse blades are provided upstream side of the corresponding bobbin in a yarn winding direction. The second traverse blade is slightly displaced with respect to the first traverse blade. The first and second traverse blades rotate in the opposite directions to traverse the yarn so that the yarn is passed between the first and second traverse blades.

[0003] However, the configuration in the Unexamined Japanese Patent Application Publication (Tokkai-Hei) No. 5-24740 has a fixed traverse width. Thus, as shown in Figure 2 of the Unexamined Japanese Patent Application Publication (Tokkai-Hei) No. 5-24740, the configuration can form only what is called cheese packages (cylindrical packages). Consequently, the configuration cannot wind monofilaments, which may involve easy collapse of the end surface of the resultant package.

[0004] The present invention has been developed in view of this problem. A main object of the present invention is to provide a yarn winding apparatus configured to allow monofilaments to be cross-wound to form a taper end package. Another object of the present invention is to provide a yarn winding method for allowing monofilaments to be cross-wound to form a taper end package.

Summary of the Invention

[0005] The problem to be solved by the present invention has been described. Now, a means for solving the problem and the effects of the means will be described.

[0006] An aspect of the present invention provides a yarn winding apparatus configured as described below. That is, the yarn winding apparatus includes a take-up tube support section configured to support a plurality of take-up tubes around which respective plural supplied yarns are wound, a plurality of traverse devices each including a yarn guide configured to be able to catch the corresponding yarn, the traverse device reciprocating the yarn guide to traverse the yarn with respect to the corresponding take-up tube, and a contact roller provided between the take-up tube support section and the plurality of traverse devices and pressed against packages formed on the respective take-up tubes. Each of the traverse devices is configured to be able to change a reciprocation range of reciprocating motion of the yarn guide. The above-described configuration can use the arrangement which includes the contact roller and which is thus characteristic of cross winding, to produce what is called taper end packages. Thus, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound.

[0007] The above-described yarn winding apparatus is further configured as follows. That is, the yarn winding apparatus further includes traverse control sections each configured to control the corresponding traverse device so that the reciprocation range of the reciprocating motion of the corresponding yarn guide decreases gradually from winding start to winding end. Each of the traverse control sections controls the traverse device so as to set a winding angle to at most one degree. This special winding angle allows the end surface shape of the taper end package to be properly finished.

[0008] Another aspect of the present invention provides a take-up winder configured as follows. That is, the take-up winder includes a spinning section configured to spin out a monofilaments and the above-described yarn winding apparatus configured to directly wind the monofilament spun out by the spinning section. According to this configuration, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound to produce a taper end package.

[0009] Furthermore, the taper end package formed using the above-described take-up winder includes the directly cross-wound monofilament.

[0010] According to another aspect of the present invention, yarn winding is carried out as follows. That is, when a plurality of yarns are cross-wound around respective take-up tubes while being traversed, a traverse range of each of the yarns is gradually reduced from winding start to winding end. According to this method, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound into what is called a taper end package.

[0011] The above-described yarn winding is further carried out as follows. That is, a winding angle is set to at most one degree. This special winding angle allows the end surface shape of the taper end package to be properly finished.

[0012] According to another aspect of the present invention, take-up winding is carried out as follows. That is, the method includes a spinning step of spinning out a monofilament, and a winding step of directly winding the spun-out monofilament, by the above-described yarn winding method. According to this spun yarn winding method, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound to produce a taper end package.

[0013] The taper end package formed using the above-described take-up winding method includes the directly cross-wound monofilament.
Other features, elements, processes, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

Brief Description of the Drawings

[0014] 

Figure 1 is a perspective view of a yarn winding apparatus according to an embodiment of the present invention.

Figure 2 is an enlarged front view of a traverse device.

Figure 3 is an enlarged view of a yarn guide.

Figure 4 is an enlarged front view of the traverse device.

Figure 5 is a control block diagram of the yarn winding apparatus.

Figure 6 is a diagram showing a control pattern for the traverse device.

Figure 7 is a partly enlarged view of a leading end portion of a bobbin holder.

Figure 8 is a diagram showing an evaluation indicator for tests for verifying the technical effects of special setting of winding angle.

Figure 9 is a diagram showing the results of calculations for verifying the technical effects of special setting of the winding angle.

Figure 10 is a diagram illustrating the causal relationship between the finish of an end surface shape and the winding angle.

Detailed Description of the Preferred Embodiments

[0015] An embodiment of the present invention will be described with reference to Figures 1 to 7.

[0016] Figure 1 is a perspective view of a yarn winding apparatus according to an embodiment of the present invention. As shown in Figure 1, a yarn winding apparatus 1 according to the present embodiment includes, as main components, bobbin holders 3 (take-up tube support section) on each of which a plurality of (in the present embodiment, four) take-up tubes are sequentially passed around the same shaft in one direction so as to sit thereon without a space between the adjacent take-up tubes, and a plurality of traverse devices 5 each including a yarn guide 4 configured to be able to catch the corresponding yarn Y, the traverse device 5 reciprocating the corresponding yarn guide 4 to traverse the corresponding yarn Y with respect to the corresponding take-up tube 2. Each of the traverse devices 5 is configured to be able to shift the reciprocation range of reciprocating motion of the corresponding yarn guide 4 in the longitudinal direction of the bobbin holders 3. The configuration of the yarn winding apparatus 1 will be described below in detail.

[0017] In the present embodiment, the yarn winding apparatus 1 is applied to a take-up winder 7 including a spinning section (not shown in the drawings) configured to simultaneously spin out a plurality of yarns Y that are synthetic yarns such as multifilaments or monofilaments. That is, the take-up winder 7 includes the spinning section configured to spin out a plurality of the yarns Y, and the yarn winding apparatus 1 configured to directly wind the plurality of yarns Y spun out by the spinning section. Each of the yarns Y spun out by the spinning section is fed to the corresponding traverse device 5 via a schematically shown traverse support point guide 8 supported by a mounting frame 6. The yarn Y is then wound around the corresponding take-up tube 2 while being traversed by the traverse device 5.

[0018] Specifically, the yarn winding apparatus 1 includes an apparatus main body 9, a turret plate 10 rotatably supported on a side surface of the apparatus main body 9, the paired bobbin holders 3 projected from the turret plate 10 in a horizontal direction, a beam 12 configured to support the plurality of traverse devices 5 and the contact roller 11, and a keyboard 13 (expansion and contraction amount input means) provided on a side surface of the apparatus main body 9.

[0019] For convenience of description, a simple reference of the term "leading end side" means the leading end side of each of the bobbin holders 3 in the projection direction of the bobbin holder 3. A simple reference of the term "base end side" means the base end side of the bobbin holder 3 in the projecting direction of the bobbin holder 3.

[0020] The paired bobbin holders 3 each support the plurality of take-up tubes 2 and are projected from the turret plate 10 in the horizontal direction like cantilevers. In this configuration, the plurality of take-up tubes are externally fitted on each of the bobbin holders 3 by being sequentially passed around the bobbin holder 3 from the leading end side toward base end side thereof and thus toward the turret plate 10. Hence, the plurality of take-up tubes 2 are arranged on the bobbin holder 3 without a space between the adjacent take-up tubes 2. Each of the bobbin holders 3 can be rotated, together with the plurality of take-up tubes 2, at a predetermined rotation number by a schematically shown bobbin holder motor 14 (see also Figure 5) provided for the bobbin holder 3.

[0021] The above-described traverse device 5 is configured to be of what is called a belt type according to the present embodiment. Figure 2 is an enlarged front view of the traverse device. As shown in Figure 2, the belt type traverse device 5 includes an endless belt 15 to which the above-described yarn guide 4 is attached, paired support units 16 configured to support the endless belt 15 so that a part of the endless belt 15 is substantially parallel to the longitudinal direction of the bobbin holder 3, and a driving motor 17 (belt driving source) configured to drive the endless belt 15. The belt type traverse device 5 is configured such that the driving motor 17 allows the endless belt 15 to travel reciprocatingly to reciprocate the yarn guide 4 substantially parallel to the longitudinal direction of the bobbin holder 3. The support unit 16 and the driving motor 17 are attached to a plate-like base 18 fixed to the beam 12 in any posture. Furthermore, to prevent the yarn guide 4 from flapping while the endless belt 15 is traveling reciprocatingly, a rail 19 is extended between the paired support units 16 so as to linearly guide the yarn guide 4.

[0022] As the endless belt 15, a timing belt is adopted according to the present embodiment. The endless belt 15 is wound around the paired support units 16 and the driving motor 17 so as to travel on an isosceles triangular trajectory.

[0023] The support unit 16 includes a pulley 20 around which the endless belt 15 is wound and a stay 21 configured to rotatably fix the pulley 20 to the base 18. The stay 21 is projected from the pulley 20 and extends toward the driving motor 17. The stay 21 is fixedly fastened to the base 18.

[0024] The driving motor 17 is a pulse motor according to the present embodiment, and is connected to a winding control section 60 (see Figure 5) described below.

[0025] The yarn guide 4 is configured to catch the yarn Y utilizing the tension of the yarn Y. Figure 3 is an enlarged view of the yarn guide 4. As shown in Figure 3, the yarn guide 4 includes a fitting section 22 having a U-shaped cross section and configured to fit attach the yarn guide 4 to the endless belt 15, and a yarn catching section 23 formed at the upper end of the fitting section 22. The yarn catching section 23 includes paired inclined portions 25 each including an inclined surface 24 along which the yarn Y traveling between the traverse support point guide 8 shown in Figure 1 and the take-up tube 2 climbs. A yarn accommodating groove 26 is formed between the inclined portions 25 so that the yarn Y is accommodated and caught in the yarn accommodating groove 26. In this configuration, when the yarn guide 4 travels in the direction of thick arrow B in Figure 3, the inclined surface 24 of the inclined portion 25 collides against the yarn Y, which is thus slightly bent by the inclined portion 25. Thus, the resultant force P of the tension of the yarn Y acting in different directions is generated in a direction opposite to the traveling direction of the yarn guide 4. The presence of the resultant force P allows the yarn Y to move along the inclined surface 24 of the inclined portion 25 toward the top of the inclined portion 25. The yarn Y is eventually accommodated in the yarn accommodating groove 26.

[0026] The spinning section (not shown in the drawings) continuously spins out the plurality of yarns Y by melting a material for synthetic yarns and ejecting the melted material through a spinneret.

[0027] The apparatus main body 9 includes a winding control section 60 (see also Figure 5).

[0028] The turret plate 10 includes a turret motor 27 (see also Figure 5) configured to rotationally drive the turret plate 10. To allow the take-up tubes 2 to be changed, the turret plate 10 is rotationally driven counterclockwise by 180 degrees by means of a turret motor 27.

[0029] The contact roller 11 is provided between the set of the plurality of belt type traverse devices 5 and the pair of bobbin holders 3. The contact roller 11 come into contact with packages formed on the respective take-up tubes 2. Furthermore, the yarns Y traversed by the respective belt type traverse devices 5 are wound around the contact roller 11. The contact roller 11 extends parallel to the longitudinal direction of the bobbin holders 3.

[0030] The beam 12 extends parallel to the longitudinal direction of the bobbin holders 3. The beam 12 includes an inclined surface 12a to which the plurality of belt type traverse devices 5 are attached. A triangular traverse surface defined when the yarn Y is traversed between the traverse support point guide 8 and the yarn guide 4 is substantially parallel to the inclined surface 12a. The triangular traverse surface has a circle-tangent relationship with the peripheral surface of the contact roller 11 as seen in a sectional view.

[0031] The configuration of the yarn winding apparatus 1 has been described. Now, the disposition relationship between the adjacent belt type traverse devices 5 will be described with reference to Figure 2.

[0032] As shown in Figure 2, in the present embodiment, the adjacent belt type traverse devices 5 are arranged so as to overlap. Specifically, the adjacent belt type traverse devices 5 are allowed to overlap by inclining the rail 19 to the longitudinal direction of the bobbin holders 3. This can be paraphrased as follows because the rail 19 corresponds to the trajectory of the reciprocation of the yarn guide 4. That is, the adjacent belt type traverse devices 5 are allowed to overlap by inclining the trajectory of reciprocation of the yarn guide 4 to the longitudinal direction of the bobbin holders 3. Moreover, in the present embodiment, the adjacent belt type traverse devices 5 are arranged so as to overlap by placing the two support units 16 substantially in a line along the traveling direction (see thick arrow A in Figure 2) of the yarn Y as seen along the normal direction of the inclined surface 12a of the beam 12 as shown in Figure 2.

[0033] Now, with reference to Figure 4, a description will be given of the guidable range within which the yarn guide 4 allows the yarn Y to be guided in the longitudinal direction of the take-up tube 2. Figure 4 is an enlarged front view of the traverse device 5. As shown in Figure 4, a straight winding shallow groove 2T is engraved at the leading end-side end of the take-up tube 2 according to the present embodiment to allow what is called straight winding (also referred to as tail end winding) to be formed. A package Q schematically shown by an alternate long and two short dashes line is formed between the straight-winding shallow groove 2T and the other end-side end of the take-up tube 2. The belt type traverse device 5 is designed to be wide enough to allow the yarn guide 4 to guide the yarn Y all over a wide range including not only the package length of the package Q but also the straight-winding shallow groove 2T.

[0034] Now, the configuration of the winding control section 60 will be described with reference to Figure 5. Figure 5 is a control block diagram of the yarn winding apparatus 1.

[0035] The winding control section 60 includes a CPU (Central Processing Unit) serving as an arithmetic processing device, a ROM (Read Only Memory) configured to store a control program executed by the CPU and data used for the control program, and a RAM (Random Access Memory) configured to temporarily store data during execution of the program. The control program stored in the ROM is read into the CPU and then executed on the CPU. The control program then allows hardware such as the CPU to function as traverse control sections (Nos. 1 to 4) 61, an origin changing section 62, and a bobbin holder control section 63. The numbers are sequentially assigned to the respective traverse control sections 61 so that No. 1 is assigned to the traverse control section 61 for the take-up tube 2 located a the leading end in Figure 1, whereas No. 4 is assigned to the traverse control section for the take-up tube located at the base end in Figure 1. Furthermore, the winding control section 60 connects to driving motors (Nos. 1 to 4) 17, the keyboard 13, the bobbin holder motor 14, and the turret motor 27. As is the case with the traverse control sections 61, the numbers are sequentially assigned to the respective driving motors 17 so that No. 1 is assigned to the driving motor 17 for the take-sup tube 2 located at the leading end in Figure 1, whereas No. 4 is assigned to the driving motor 17 for the take-up tube 2 located at the base end in Figure 1.

[0036] Each of the traverse control sections (Nos. 1 to 4) 61 includes a control pattern storage section 64 and an origin control section 65. Each of the traverse control sections (Nos. 1 to 4) 61 control the corresponding one of the driving motors (Nos. 1 to 4) 17 for the respective belt type traverse devices 5 based on a control pattern stored in the control pattern storage section 64 and an origin stored in the origin control section 65. Specifically, each of the traverse control sections (Nos. 1 to 4) 61 is configured to be able to control the corresponding one of the driving motors (Nos. 1 to 4) 17 so that yarn density is equivalent between the vicinities of the opposite ends of the package Q formed on the take-up tube 2.

[0037] The control pattern for each driving motor 17 is stored in the corresponding control pattern storage section 64. In the present embodiment, the control pattern is created such that the package Q formed on the take-up tube 2 is such a taper end package as schematically shown by an alternate long and two short dashes line in Figure 4, that is, such that the interval between traversing reversals decreases gradually. In other words, the reciprocation width of reciprocating motion of the yarn guide 4 decreases gradually from winding start to winding end. The belt type traverse device 5 according to the present embodiment is configured so as to vary the reversal interval to enable the reciprocation width of reciprocating motion of the yarn guide 4. An example of the control pattern is shown in Figure 6. Figure 6 shows a control pattern for the traverse device 5. In Figure 6, the axis of ordinate indicates traverse speed Vt, and the axis of abscissa indicates time (t). In Figure 4, the traverse speed Vt at which the yarn guide 4 moves toward the leading end side is denoted by (+). Specifically, as shown in Figure 6, the control pattern according to the present embodiment is created such that the motion pattern of the yarn guide 4 varies between the vicinities of the opposite traverse ends. More specifically, the traverse speed Vt of the yarn guide 4 is set to have a slightly larger value immediately after reversal of the yarn guide 4 following arrival at the right end of the reciprocation range of the reciprocating motion. That is, feed-forward control is performed only at the right end in order to prevent the yarn Y from being retained during the reversal. The control pattern shown in Figure 6 is created such that winding angle is 0.5 degrees. The winding angle is preferably set to at most one degree. As is well known, the winding angle may be adjusted by, for example, increasing or reducing the amplitude of the traverse speed Vt.

[0038] The origin storage section 65 stores the origin serving as a basis for the reciprocating motion of the yarn guide 4 of the belt type traverse device 5. Here, in the present embodiment, the "origin" means the position of the central point of reciprocating motion of the yarn guide 4 of the belt type traverse device 5.

[0039] The origin changing section 62 changes the origin stored in the origin storage section 65 of each of the traverse control sections (Nos. 1 to 4) 61 based on the expansion and contraction amount of the take-up tube 2 input via the keyboard 13. Figure 7 is a partly enlarged view of the leading end of the bobbin holder 3. Specifically, the expansion and contraction amount relates to the direction of the bobbin length of the plurality of take-up tubes 2 as a whole. The expansion and contraction amount can be acquired by reading, on a scale S engraved on the bobbin holder 3 as shown in Figure 7, the position of the leading end-side end surface E of one of the plurality of take-up tubes 2 which is closest to the leading end; the plurality of take-up tubes 2 are passed around the bobbin holder 3 in one direction so as to sit thereon without a space between the adjacent take-up tubes 2. For example, if the position of the leading end-side end surface E of the take-up tube 2 corresponds to "-2. 8 mm" on the scale S as shown in Figure 7, the expansion and contraction amount is "-2. 8 mm". Then, the origin changing section 62 adds the expansion and contraction amount ΔL divided by 8 multiplied by 7, that is, 7/8ΔL, to the origin stored in the origin storage section 65 of the traverse control section (No. 1) 61. Similarly, the origin changing section 62 adds 5/8ΔL, 3/8ΔL, and 1/8ΔL to the origin stored in the origin storage section 65 of the traverse control section (No. 2) 61, the origin stored in the origin storage section 65 of the traverse control section (No. 3) 61, and the origin stored in the origin storage section 65 of the traverse control section (No. 4) 61, respectively. The above-described operation of the origin changing section 62 is based on the assumption that the take-up tube length varies depending on the humidity of the environment in which the apparatus is used because the take-up tube 2 is made of paper and that the variation in bobbin length is equivalent for all the take-up tubes 2.

[0040] The bobbin holder control section 63 controls rotation of the bobbin holder motor 14.

[0041] Furthermore, the winding control section 60 includes a turret control section configured to control rotation of the turret motor 27.

[0042] Now, operations according to the present embodiment will be described. First, four empty take-up tubes 2 are sequentially passed around each of the paired bobbin holders 3 toward the turret plate 10 so as to sit on the bobbin holder 3 without a space between the adjacent take-up tubes 2.

[0043] An operator operates the keyboard 13 or the like to actuate the take-up winder 7. The operator then reads and inputs the expansion and contraction amount to the winding control section 60. Then, the origin changing section 62 changes the origin stored in the origin storage section 65 of each of the traverse control sections (Nos. 1 to 4) 61 as described above. The change in origin slightly shifts the reciprocation range of reciprocating motion of the yarn guide 4 in the longitudinal direction of the bobbin holder 3.

[0044] The four yarns Y spun out by the spinning section (spinning step) are sucked and held by a suction gun (not shown in the drawings). The bobbin holder control section 63 drives the bobbin holder motor 14 so as to rotate the take-up tubes 2 at the desired rotation number. Each of the yarns Y sucked and held by the suction gun is guided to the straight-winding shallow groove 2T in the corresponding take-up tube 2. Thus, the yarn Y is firmly gripped by the straight-winding shallow groove 2T in the take-up tube 2. The yarn Y sucked and held by the suction gun is then released and moves from the straight-winding shallow groove 2T onto the outer peripheral surface of the take-up tube 2. The yarn Y moves spirally toward the center of the bobbin length of the take-up tube 2.

[0045] Then, each of the traverse control sections (Nos. 1 to 4) 61 controls the corresponding one of the driving motors (Nos. 1 to 4) 17 based on the control pattern stored in the corresponding control pattern storage section 64 and the origin stored in the corresponding origin storage section 65. Thus, each of the yarns Y is caught by the corresponding yarn guide 4 and starts to be traversed so as to be cross-wound (see also Figure 3). The yarn Y is thus cross-wound into such a taper end package Q as shown in Figure 4, on the take-up tube 2 (winding step).

[0046] When the package Q becomes full, the turret control section drives the turret motor 27 to rotate the turret plate 10 counterclockwise by 180 degrees. Each of the traverse control sections (Nos. 1 to 4) further moves the corresponding yarn guide 4 to a position located opposite the corresponding straight-winding shallow groove 2T. Then, each of the yarns Y is firmly gripped by the straight-winding shallow groove 2T in the corresponding empty take-up tube 2 as described above. Subsequently, each of the traverse control sections (Nos. 1 to 4) 61 controls the corresponding one of the driving motors (Nos. 1 to 4) 17 again based on the control pattern stored in the control pattern storage section 64 and the origin stored in the origin storage section 65. Thus, the yarn Y is constantly caught by the yarn guide 4 and cross-wound into such a taper end package Q as shown in Figure 4, on the take-up tube 2 again.

[0047] Now, tests for verifying the technical effects of setting the winding angle to at most one degree will be described. The numerical limitation of the winding angle has been reasonably backed up by the following verification tests. In the verification tests described below, the relationship between the finish of the end surface shape of the taper end package Q and the winding angle was examined using the above-described yarn winding apparatus 1.

[0048] First, an evaluation method for the verification tests will be described. Figure 8 is a diagram showing an evaluation indicator for the tests for verifying the technical effects of special setting for the winding angle. Figure 8A shows the appearance of a taper end packaged according to the embodiment.
Figure 8B shows the appearance of a taper end package in a comparative example. That is, the end surface shape of a full package is observed, and an end surface shape having a linear, beautiful silhouette as shown in Figure 8A is determined to be "o (good)". On the other hand, an end surface shape obviously including protrusions and recesses as shown in Figure 8B is determined to be "x (bad)". If it is impossible to determine whether the end surface shape is "o" or "x", the end surface shape is determined to be "Δ".

[0049] Test conditions common to all the confirmation tests are as follows.

• Yarn Y: monofilaments with a generally circular cross section (20 dtex)
• Diameter of the take-up tube: φ110 mm
• Diameter of the taper end package Q: φ200 mum
• winding width of the taper end package Q: winding start = 270 mm, winding end = 114 mm
• Taper angle A (see Figure 8) of end surface of the taper end package Q: 30 [deg.]
• Winding angle θ (see also Figure 8) : as shown in Table 1. The traverse speed Vt set to have a slightly larger value immediately after the reversal as shown in Figure 6 is not taken into account.
• Free length ΔF (see Figure 4), that is, the distance over which the yarn Y travel between the yarn guide 4 and the contact roller 11, can be set to between 25 mm and 45 mm. In the present tests, the free length was set to 25 mm.

[0050] The results of the verification tests are shown in Table 1.

[0051] 

(Table 1)

Winding angle θ deg.	Evaluation for finish of end surface shape
6.0	×
2.0	×
1.2	Δ
1.0	○
0.5	○
0.2	○

[0052] Table 1 shows that a winding angle of at most one degree allows the end surface shape to be properly finished. Furthermore, the finish of the end surface shape which can be obtained at a winding angle of at most one degree failed to be achieved at a winding angle of at least 1. 2 degrees.

[0053] How the present inventors have found the special numerical limitation of the winding angle θ [deg.] will be described below.

[0054] In general, in order to cross-wind multifilaments into a cheese package, it is technically common to set the traverse winding θ [deg.] to 4 to 8. This is because a winding angle θ [deg.] of less than 4 causes the end surface of the cheese package to be bulged in the longitudinal direction of the package, whereas a winding angle θ [deg.] of more than 8 causes the end surface of the cheese package to be shrunk and wrinkled.

[0055] According to the present embodiment, the taper end package is adopted because when the monofilaments are cross-wound into a package, the end surface of the resultant package is easily collapsed. However, owing to the above-described technically common knowledge, the present inventors initially adopted a winding angle θ [deg.] of 4. At this winding angle θ [deg.], the end surface of the finished taper end package obviously had protrusions and recesses and was thus visually unfavorable as shown in Figure 8B.

[0056] Then, the present inventors realized that this set value of the winding angle θ [deg.] is originally intended for cheese packages, and thus dared to increase the set value. The present inventors then found that setting the winding angle θ [deg.] to a value smaller than the above-described one, that is, to at most one degree, allows the end surface shape to be properly finished as shown in Figure 8B.

[0057] Thus, the present inventors carried out the above-described verification tests and calculated winding density in a well-known manner in order to mathematically determine the significance of the numerical limitation. Figure 9 shows the results of the calculations for verifying the technical effects of the special setting of the winding angle θ [deg.]. That is, Figure 9A shows the distribution of the winding density obtained when the winding angle θ [deg.] is set to 0. 5. Figure 9B shows the distribution of the winding density obtained when the winding angle θ [deg.] is set to 6. 0. The axis of abscissa in Figures 9A and 9B indicates a winding width position [mm], that is, a longitudinal position on the package. The longitudinal end of the package at the winding start corresponds to the winding width position = 0 mm. The axis of ordinate indicates the winding density [%]. The winding density means the spatial sectional area occupied by the yarn. The winding density [%] at the longitudinal center of the package is 100. Figures 9A and 9B show that a winding angle θ [deg.] of 0. 5 results in a uniform winding density [%] from the longitudinal center to longitudinal end of the package. In contrast, a winding angle θ [deg.] of 0. 5 makes the winding density [%] extremely higher at the longitudinal end of the package than at the longitudinal center thereof. This is assumed to be because as shown in Figure 10, an increase in winding angle θ [deg.] further hinders the yarn from following the motion of the yarn guide during the reversal of the yarn guide, causing the yarn to be retained at the longitudinal end of the package for a loner time than at the longitudinal center thereof. Calculation data shown by a dashed line in Figure 9B corresponds to the motion of the yarn before the reversal thereof (not the reversal of the yarn guide) shown in Figure 10B. Calculation data shown by a solid line in Figure 9B corresponds to the motion of the yarn after the reversal thereof shown in Figure 10B. That is, the yarn properly follows the motion of the yarn guide before the reversal of the yarn but has difficulty following the motion of the yarn guide particularly after the reversal of the yarn. This is indicated by the different calculation data shown by the solid and dashed lines on the graph in Figure 9B.

[0058] As described above, in the above-described embodiment, the yarn winding apparatus 1 is configured as follows. That is, the yarn winding apparatus 1 includes the bobbin holders 3 configured to support the plurality of take-up tubes 2 around which the respective plural supplied yarns Y are wound, the plurality of belt type traverse devices 5 each including the yarn guide 4 configured to be able to catch the corresponding yarn Y, the traverse device 5 reciprocating the yarn guide 4 to traverse the yarn Y with respect to the corresponding take-up tube 2, and the contact roller 11 provided between, the set of the plurality of traverse devices 5 and the bobbin holders 3 and pressed against the packages Q formed on the respective take-up tubes 2. Each of the belt type traverse devices 5 is configured to be able to change the reciprocation range of reciprocating motion of the yarn guide 4. The above-described configuration can use the arrangement which includes the contact roller 11 and which is thus characteristic of cross winding, to produce what is called taper end packages Q. Thus, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound.

[0059] The above-described yarn winding apparatus 1 is further configured as follows. That is, the yarn winding apparatus 1 further includes the traverse control sections (Nos. 1 to 4) 61 each configured to control the corresponding belt-type traverse device 5 so that the reciprocation range of the reciprocating motion of the corresponding yarn guide 4 decreases gradually from winding start to winding end. Each of the traverse control sections (Nos. 1 to 4) 61 controls the belt type traverse device 5 so as to set the winding angle θ [deg.] to at most one degree. This special winding angle θ [deg.] allows the end surface shape of the taper end package to be properly finished.

[0060] Furthermore, the take-up winder 7 is configured as follows. That is, the take-up winder 7 includes the spinning section configured to spin out a monofilament and the above-described yarn winding apparatus 1 configured to directly wind the monofilament spun out by the spinning section. According to this configuration, the monofilaments, which may involve easy collapse of the end surface of the resultant package, can be cross-wound to produce the taper end package Q.

[0061] Furthermore, the taper end package Q formed using the above-described take-up winder 7 includes the directly cross-wound monofilament.

[0062] According to another aspect of the present invention, yarn winding is carried out as follows. That is, when the plurality of yarns Y are cross-wound around the respective take-up tubes 2 while being traversed, the traverse range of each of the yarns Y is gradually reduced from winding start to winding end. According to this method, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound into what is called the taper end package Q.

[0063] The above-described yarn winding is further carried out as follows. That is, the winding angle θ [deg.]is set to at most one degree. This special winding angle θ [deg.] allows the end surface shape of the taper end package Q to be properly finished.

[0064] Furthermore, take-up winding is carried out as follows. That is, the method includes the spinning step of spinning out a monofilament, and the winding step of directly winding the spun-out monofilament by the above-described yarn winding method. According to this take-up winding method, the monofilament, which may involve easy collapse of the end surface of the resultant package, can be cross-wound to produce a taper end package Q.

[0065] The taper end package Q formed using the above-described take-up winding method includes the directly cross-wound monofilament.

[0066] The preferred embodiment of the present invention has been described above. However, the above-described embodiment may be varied as follows.

[0067] For example, in the above-described embodiment, the belt type traverse device is adopted as the traverse device 5. However, instead, another traverse device 5, for example, an arm type traverse device or a cam type traverse device, may be adopted provided that the traverse device allows the reciprocation width of reciprocating motion of the yarn guide 4 to be changed. The arm type traverse device uses a driving motor configured as a voice coil motor to drive an arm member with a yarn guide formed at the leading end thereof so that the arm member can be reciprocatingly turned. Furthermore, the cam type traverse device includes a traverse cam, a traverse guide configured to engage with a traverse groove spirally formed in the traverse cam and move slidably along the traverse groove, and a traverse guide driving motor configured to rotate the traverse cam.

[0068] Furthermore, in the above-described embodiment, mostly monofilaments are wound. However, instead, multifilaments may be cross-wound to form a taper end package.

[0069] In the specification, the taper end package means a package with a taper angle A of at most 45 degrees in Figure 8.

[0070] Additionally, the yarn winding apparatus 1 according to the present invention is intended for cross winding. What is called parn winding is not included in the technical scope of the invention disclosed in the present Application.
While the present invention has been described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the present invention that fall within the scope of the invention.

Claims

1. A yarn winding apparatus characterized by including:

a take-up tube support section configured to support a plurality of take-up tubes around which respective plural supplied yarns are wound;

a plurality of traverse devices each including a yarn guide configured to be able to catch the corresponding yarn, the traverse device reciprocating the yarn guide to traverse the yarn with respect to the corresponding take-up tube; and

a contact roller provided between the take-up tube support section and the plurality of traverse devices and pressed against packages formed on the respective take-up tubes, and

in that each of the traverse devices is configured to be able to change a reciprocation range of reciprocating motion of said yarn guide.

2. The yarn winding apparatus according to Claim 1,
characterized by further including traverse control sections each configured to control the corresponding traverse device so that the reciprocation range of the reciprocating motion of the corresponding yarn guide decreases gradually from winding start to winding end, and
in that each of the traverse control sections controls the traverse device so as to set a winding angle to at most one degree.

3. A take-up yarn winder characterized by including:

a spinning section configured to spin out a monofilament; and

a yarn winding apparatus according to Claim 1 or Claim 2 configured to directly wind the monofilament spun out by the spinning section.

4. A taper end package formed using a take-up winder according to Claim 3.

5. The yarn winding method characterized in that when a plurality of yarns are cross-wound around respective take-up tubes while being traversed, a traverse range of each of the yarns is gradually reduced from winding start to winding end.

6. The yarn winding method according to Claim 5,
characterized in that a winding angle is set to at most one degree.

7. A take-up spun yarn winding method characterized by including:

a spinning step of spinning out a monofilament; and

a winding step of directly winding the spun-out monofilaments by a yarn winding method according to Claim 5 or Claim 6.

8. A taper end package formed using a take-up winder according to Claim 7.

Drawing