Elastic yarn take-up winder and package

Abstract: An elastic yarn package which enables the tail-end yarn tip to be easily found and drawn out, and the elastic yarn take-up winder which produces this package are provided. An elastic yarn take-up device provided with a yarn transfer means for transferring yarn that is being wound from a full bobbin FB to an empty bobbin EB comprises a tail-end yarn guide 14 which moves yarn that is lead onto the full bobbin to an end Ba of the bobbin B that is away from the layered yarn section Pa, and further comprising a lead-end yarn guide 15 which moves yarn led onto an empty bobbin to a position outside of the yarn path along which the yarn is being led to the full bobbin, is provided. Further, the elastic yarn package in which the tail-end yarn tip is wound onto an end section of the bobbin away from the layered yarn section of the bobbin is also provided.

Description: The present invention relates to a method for operating an elastic yarn take-up winder and an elastic yarn take-up winder according to the preamble of claim 1 and 2, respectively, as well as an elastic yarn package obtained by the method and/or the take-up winder. A conventional turret-type elastic yarn take-up winder as disclosed in DE-A-4 414 180 switches the positions of bobbin holders by rotating a turret to which two bobbin holders are attached such that when a package becomes full, the package is exchanged with the empty bobbin holder, enabling continuous yarn winding. In such a conventional take-up winder, the turret is operated to rotate in the counter-clockwise direction, moving the full bobbin from the winding position to an intermediary position, and the empty bobbin from the stand-by position to the intermediary position, and then stopped. Next, a yarn winding guide which comprises the winding means winds the elastic yarn once around the empty bobbin, a high-speed brake is applied to the full bobbin, the elastic yarn is loosened, and a section of the yarn is adhered onto the surface of the empty bobbin. When the yarn section is taken-up onto the surface of the empty bobbin, the yarn tension generated when the yarn section between the empty bobbin and the full bobbin is wound around the empty bobbin causes the yarn to break between the empty and full bobbins. The yarn which follows the yarn that is adhered onto the empty bobbin is wound on top of the new lead-end yarn tip, fixing it in place. After the yarn winding guide is returned to place, the empty bobbin is returned to the winding position, and actual winding is carried out by the traverse device. When the yarn that is wound is not elastic yarn, but synthetic yarn such as polyester or nylon, the tail-end yarn tip is placed on the top yarn layer of the layered package wound by the take-up winder upon completion of winding. In the conventional wound package of synthetic yarn, placing the tail-end yarn tip on top of the layered yarn is not a problem, but when the package is a wound package of elastic yarn, the adhesiveness of the elastic yarn may make finding and drawing out the tail-end yarn tip problematic at the next stage of processing. It is therefore an object of the present invention to provide a method for operating an elastic yarn take-up winder and an elastic yarn take-up winder for producing packages in which the wound yarn end can be easily found and drawn out. This problem is solved by the features of the characterizing portion of claim 1 and 2, respectively. The elastic yarn take-up winder comprises a yarn transfer means for transferring the yarn from a full bobbin to an empty bobbin, a tail-end yarn guide for placing yarn introduced to the full bobbin at the end section of a bobbin, away from the layered yarn section of the bobbin, and a lead-end yarn guide for placing the yarn introduced to the empty bobbin at a position outside the yarn path along which the yarn is lead to the full bobbin. The tail-end yarn guide may be an independently moveable moving guide which moves along the bobbin in the bobbin's axial direction. Also the lead-end yarn guide may be independently moveable along the bobbin in the bobbin's axial direction. Brief Description of the Drawing Figure 1 is a schematic drawing showing a front view of the winder after winding of a bobbin has been completed; Figure 2A ∼ Figure 2F are schematic drawings showing front views of the yarn transfer procedure in the elastic yarn take-up winder of the present invention; Figure 3 is a schematic drawing showing an enlarged front view of the elastic yarn take-up winder of the present invention which is used to explain in detail the operation when yarn is transferred using a tail-end yarn guide and a lead-end yarn guide. Figure 4 is a schematic drawing showing a planar view from the IV-IV plane of Figure 3. Figure 5A and 5B show different embodiments of elastic yarn packages. Figure 5A is a planar view of a package in which the tail-end yarn Yd is wound at an end section Ba of a bobbin, away from the layered section Pa and the lead-end yarn Yc is wound at the layered section of the bobbin. Figure 5B is a planar view of a package in which the tail-end yarn Yd is wound at an end section Ba of the bobbin, away from the layered section and the lead-end yarn Yc is wound around an end section Bb of the bobbin away from the layered section. Detailed Description of the Preferred Embodiments In Figure 1, M is an elastic yarn take-up winder comprising a machine frame 7 provided with an elevating box 1 which may to independently rise and descend, a rotatable turret 2 and a fixed frame 8 on the front of which a control panel 9 is arranged. A contact roller 3 and a traverse device 4 are held in the elevating box 1. The contact roller 3 applies pressure against the yarn layer surface of a bobbin B at a winding position P 1 . The contact roller 3 is rotationally driven by a driving source (not shown) such that the bobbin B being wound is rotated in a counter-clockwise direction. A traverse guide 5 is arranged in the traverse device 4, and engages with an elastic yarn Y, traversing the elastic yarn Y by running within a traverse range. A yarn separating guide (not shown) for separating the yarn from the traverse guide 5 is arranged in the upstream side of the traverse device 4. The turret 2 is rotatable via a rotational driving device (not shown) centered around a rotary shaft 6. Two bobbin holders 11,12 are independently rotatable in the turret 2. A plurality of bobbins B are inserted in each of the bobbin holders 11, 12, with one of the bobbin holders 11 arranged at the winding position P 1 and the other 12 at the stand-by position P 2 . In Figure 4, only one bobbin B is shown. The elastic yarn Y on the bobbin B of the bobbin holder 11 positioned at the winding position P 1 is wound, and when it becomes a full bobbin FB, the turret 2 is rotated. The full bobbin FB is moved from the winding position P 1 to the stand-by position P 2 , and the pre-arranged empty bobbin EB at the stand-by position P 2 is moved from the stand-by position P 2 to the winding position P 1 . While they are moving, the elastic yarn Y is transferred from the full bobbin FB to the empty bobbin EB via a yarn exchange guide means 13, allowing yarn winding to continue uninterruptedly. In the present invention, the yarn exchange guide means 13 is comprised of a tail-end yarn guide 14 and a lead-end yarn guide 15. The tail-end yarn guide 14 positions the yarn Y introduced to the full bobbin FB at an end section Ba of the bobbin B away from the layered yarn section Pa. It comprises of a rod-shaped moving guide 16 with comb-like structures, and is arranged so as to be independently moveable along the central axis of the bobbin B. The tail-end yarn guide 14 is attached to the turret 2 such that the rod-shaped moving guide 16 extends along the rotational axis of the turret 2, dividing the winding position bobbin holder and the stand-by position bobbin holder. However, in order to make the large diameter portion of the full bobbin FB bigger, the tail-end yarn guide 14 is preferably attached on the side of the frame 7 instead of to the turret 2, such that it can advance between the full bobbin FB and the empty bobbin EB. The rod-shaped moving guide 16 may move between the stand-by position at the far end Bb of the bobbin B shown by the double dotted chain line in Figure 4, and the near end Ba of the bobbin B indicated by the continuous line. The lead-end yarn guide 15 is comprised of a swinging arm 17 axially supported in the lower portion of the frame 7 and a guide bar 18 attached to the tip of the swinging arm 17. The swinging arm 17 is arranged on the side of the front ends of the bobbin holders 11, 12, and the guide bar 18 is cantilevered from the front ends of the bobbin holders 11, 12 towards the base end of the bobbin holders 11, 12. The rotary shaft 19 of the swinging arm 17 is arranged such that the elastic yarn Y can be wound around the empty bobbin EB by the guide bar 18 when the empty bobbin EB is at the yarn exchange position, or in other words, when it is at the intermediary position P 4 indicated by the double dotted chain line in Figure 1. The swinging arm 17 is normally set such that the guide bar 18 and other elements do not come into contact with the full bobbin FB when the turret 2 is rotated. The swinging arm 17 of the lead-end yarn guide 15 is arranged such that it can swing roughly 180 degrees around the center of the rotary axis 19 via a driving means such as a rotary actuator (not shown). The guide bar 18 of the lead-end yarn guide 15 is attached to the end of swinging am 17, and is provided with a guiding groove 20 shown in Figure 4, into which slides the elastic yarn Y. The guiding groove 20 is provided with two curved portions 21 that taper in towards each other. These curved portions 21 help to guide the elastic yarn Y along a curved path. By guiding the elastic yarn Y along the curved portions 21, the yarn Y can be reliably guided to the bottom of the guiding groove 20. The lead-end yarn guide 15 may also be arranged so as to be independently moveable along the axial direction of the bobbin B, as indicated by the double dotted chain line in Figure 4. When the lead-end yarn guide 15 moves in the axial direction of the bobbin B, the lead-end yarn is wound at the end section Bb of the bobbin B, away from the layered yarn section Pa of the bobbin B, and on the opposite end of the bobbin B from the end at which the tail-end yarn is wound. The yarn transfer will now be explained using Figure 2A ∼ Figure 2F. In Figure 2A the winding of the bobbin B has been completed, and the full bobbin FB is at the winding position P 1 . At this stage, by rotating the turret 2 in the counter-clockwise direction, the empty bobbin EB is brought to the winding side, and into contact with the elastic yarn Y which is drawn by the full bobbin FB (Figure 2B). Further rotation of the turret 2 moves the full bobbin FB from the winding position P 1 to the intermediary position P 3 , and the empty bobbin EB from the stand-by position P 2 to the intermediary position P 4 . At this point, the rotation of the turret 2 is stopped (Figure 2C). The yarn Y is removed from the traverse device 4 by a yarn separating guide (not shown in the drawing). At the stage shown in Figure 2C, the lead-end yarn guide 15 is operated. The lead-end yarn guide 15 catches the yarn section Ya of elastic yarn Y between the empty bobbin EB in the intermediary position P 4 and the full bobbin FB in the intermediary position P 3 , and moves it from the path indicated by the double dotted chain line in Figure 2C to the path indicated by the continuous line (changing the yarn path to that indicated by 1 ○ in Figure 3), in order to form a bunch winding in the middle section of the empty bobbin EB. In Figure 2D, the tail-end yarn guide 14 is operated from back to front in a direction perpendicular to the plane of the page, catching the yarn section Ya of the elastic yarn Y, and moving it from the path indicated by the double dotted chain line to the path indicated by the continuous line (changing the yarn path to that indicated by 2 ○ in Figure 3). In other words, the yarn section Ya is moved from the layered section Pa to the end section Ba of the full bobbin Fb. As a result, the tail end yarn is bunch-wound at the end section B of the full bobbin Fb. By moving the yarn section Ya from the layered yarn section Pa to the end section Ba of the full bobbin FB, the tension of the yarn section Ya is reduced. Thus, the yarn section Ya is wound onto the surface of the empty bobbin EB. The yarn tension created when the yarn section Ya between the empty bobbin Eb and the full bobbin Fb causes the yarn to break between the empty bobbin EB and the full bobbin FB, and the yarn which follows the elastic yarn Y from the tail-end wound onto the empty bobbin EB is wound on top of the new lead-end yarn tip. After the lead-end yarn guide 15 moves back to its original position, the empty bobbin EB is returned to the winding position P 1 , as shown in Figure 2E and Figure 2F, and the actual winding is carried out with the traverse device 4. Next, the structure of the package processed by the above-described elastic yarn take-up winder will be described in reference to Figure 5. In the first embodiment of the package P, shown in Figure 5A, the lead-end yarn Yc is formed as a bunch winding in the middle section in the axial direction of the bobbin B (the middle section in the axial direction of the layered yarn section Pa), and the tail-end yarn Yd is moved from the layered yarn section Pa and wound around one end Ba of the bobbin B. In the second embodiment of the package P, shown in Figure 5B, the lead-end yarn Yc is moved from the layered yarn section Pa and wound at one end Bb of the bobbin B. The tail-end yarn tip Yd, is moved from the layered yarn section Pa to the other end Ba of the bobbin B. In either of these two embodiments, the tail-end yarn tip Yd is wound onto one end of the bobbin Ba away from the layered yarn section Pa, and it is therefore easy to find the tail-end yarn Yd and to draw it out. Further, in the second embodiment of the package, the lead-end yarn Yc is wound onto a different end Bb of the bobbin B as the tail-end yarn Yd, and thus it is not only easy to find the lead-end yarn Yc and to draw it out, but the lead-end yarn Yc and the tail-end yarn Yd do not overlap.

Claims: Method for operating an elastic yarn take-up winder comprising a yarn transfer means (13) for transferring a yarn from at least one full bobbin (FB) to at least one empty bobbin (EB) held on a respective bobbin holder (11, 12) for the full and the empty bobbin (FB, EB), respectively, wherein each bobbin comprises an area for a layered yarn section (Pa) and two end sections (Ba, Bb) actually outside the area for the layered yarn section (Pa), characterized in that a tail-end bunch-winding (Yd) leading the yarn to one of the end sections (Ba, Bb) outside the layered yarn section (Pa) of the full bobbin (FB) is formed by a tail-end yarn guide (14), and a lead-end bunch-winding (Yc) guiding the yarn to one of the end sections (Ba, Bb) of the empty bobbin (EB) or to the area for the layered yarn section (Pa) is formed by a lead-end yarn guide (15). An elastic yarn take-up winder comprising a yarn transfer means (13) for transferring a yarn from at least one full bobbin (FB) to at least one empty bobbin (EB) held on a respective bobbin holder (11, 12) for the full and the empty bobbin (FB, EB), respectively, wherein each bobbin comprises an area for a layered yarn section (Pa) and two end sections (Ba, Bb) actually outside the area for the layered yarn section (Pa), characterized by a tail-end yarn guide (14) for forming a tail-end bunch-winding (Yd) leading the yarn to one of the end sections (Ba, Bb) outside the layered yarn section (Pa) of the full bobbin (FB), and a lead-end yarn guide (15) for forming a lead-end bunch-winding (Yc) guiding the yarn to one of the end sections (Ba, Bb) of the empty bobbin (EB) or to the area for the layered yarn section (Pa). An elastic yarn take-up winder according to claim 2, characterized in that the positions of the tail-end bunch-winding (Yd) and the lead-end bunch-winding (Yc) are different. An elastic take-up winder according to claim 3 characterized in that, the tail-end bunch-winding (Yd) and the lead-end bunch-winding (Yc) are formed on different end sections (Ba, Bb). An elastic yarn take-up winder according to one of the claims 2 to 4 characterized in that, the tail-end yarn guide (14) is moveable along the central axis of the full bobbin (FB) between the end-sections (Ba, Bb) thereof. An elastic yarn take-up winder according to one of the claims 2 to 5 characterized in that, the lead-end yarn guide (15) is moveable along the central axis of the empty bobbin (EB) between the end sections (Ba, Bb) thereof. An elastic take-up winder according to one of the claims 2 to 6 characterized in that, the lead-end yarn guide (15) is provided with a swinging arm (17) which swings around the center of a rotary axis (19), and a guide bar (18) attached to the swinging arm, and wherein a yarn guide groove (20) is formed in the guide bar (18). An elastic yarn package obtained by the method and/or the take-up winder according to one of the claims 1 to 7.

Inventors: HASHIMOTO KINZO, HASHIMOTO, KINZO
Applicants: MURATA MACHINERY LTD, MURATA KIKAI KABUSHIKI KAISHA
Application year: 1998
Main classification: B65H67
IPC codes: B65H67, B65H65, B65H54