Abstract:
An apparatus and a method for winding a web of tapes or yarns to a plurality of packages, wherein a plurality of winding positions are arranged side by side on a long side of the apparatus, with at least one package being wound in each winding position. To distribute the tapes or yarns of the web, a yarn guide bar and a plurality of yarn guides are provided, the yarn guides being associated with respective ones of the winding positions. In this process, the web of tapes or yarns is guided above the winding positions in a distribution plane that extends transverse to the long side of the apparatus. The yarn guide bar is movable so as to permit unimpeded access to the winding positions in a doffing plane which is parallel to the long side of the apparatus, to facilitate doffing of the full packages with the aid of an auxiliary device which can be guided in the doffing plane.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus and method for winding a web of tapes or yarns into a plurality of packages. 
     It is known to produce film tapes from thermoplastic high-polymer plastics for various uses with the therefor required specific product properties. Such uses include, for example, tapes for weaving carpet backings, or for packaging fabric, film tapes for producing twines, cords, or ropes, as well as film tapes as a raw material for splicing yarns and similar products. 
     In the known extrusion lines, plastics are plasticized in a continuous process, and extruded in the molten state as an endless film by a die, preferably a wide-slot die. This endless film is quenched in a tempered cooling bath to below the softening point of the plastic. After cutting the edges of the endless film, the flat film is divided into a web of narrow, flat tapes, which are monoaxially drawn in a lengthwise orientation between arrangements of rolls or godets, which are designed and constructed preferably as draw units looped by the tapes, and between which hot-air ovens are arranged. 
     The narrow, flat tapes are wound into respective packages by means of a winding device. As is disclosed, for example, in DE 34 14 636, after leaving the last godet, the web of narrow tapes advances over a yarn guide bar which mounts a plurality of yarn guides, before the individual tapes of the web are distributed to individual winding positions. The winding positions extend along a long side of the machine. To distribute the film tapes, the web of tapes advances in a plane above the winding positions. In each winding position, a tape is wound to a cross-wound package. At the time the package mounted on a winding spindle has reached its intended size, it becomes necessary to doff the package. To this end, the tape is cut and advanced to waste by means of a suction gun. The package is removed from the winding spindle and replaced with an empty tube. Subsequently, the tape is threaded on the empty tube to wind a new package. The package doff is carried out manually. Thus, the known apparatus is suitable only to produce packages with a relatively low weight. 
     It is therefore an object of the invention to further develop an apparatus and a method of the initially described kind such that it is possible to wind and doff packages of a greater weight, in particular greater than 12 kg. 
     SUMMARY OF THE INVENTION 
     The invention distinguishes itself in that it permits doffing the packages in the winding positions with the use of an auxiliary device, which is adapted for unimpeded movement in a doffing plane, which extends parallel to the long side of the machine. In accordance with the invention, the web of slit-film tapes advancing crosswise to the long side of the machine is guided out of a distribution plane for purposes of doffing the packages, so that none of the slit-film tapes traverse the doffing plane. To this end, the yarn guide bar upstream of the winding positions is made movable. Thus, the yarn guide bar is moved out of its operating position only for doffing the packages, in order to deflect the web of slit-film tapes. 
     According to an advantageous further aspect of the invention, the movement of the yarn guide bar is performed by a drive at a uniform guiding speed. This ensures that no sudden fluctuations in the yarn tension can occur, so that during the movement of the yarn guide bar, winding of the slit-film tape can continue unimpeded. 
     To be able to perform the movement of the yarn guide bar with simple means, an advantageous further feature of the invention provides that one end of the yarn guide bar is designed and constructed as a pivot bearing. In this instance, a pivot drive pivots the yarn guide bar crosswise to the direction of the advancing yarn. Preferably, a stop is used to define the operating position of the yarn guide bar and its deflected position. 
     To ensure a great flexibility in winding the slit-film tapes of the web, a preferred further feature of the invention provides that in each winding position the auxiliary device traveling in the doffing plane doffs the packages, one after the other. Preferably, the auxiliary device is formed by a package manipulator arranged on an overhead conveyor. Thus, the package manipulator is used to remove only the full package from the winding spindle of the winding position and to transport the full package, for example, to an adjacent creel. 
     Since the looping of the individual slit-film tapes of the web changes in the deflected position of the yarn guide bar, a further advantageous feature provides that the yarn guide bar is equipped with a plurality of yarn guides, which each comprise a guide edge partially surrounding the tape for guiding it. This ensure a reliable guidance of the slit-film tapes of the web in each position of the yarn guide bar. 
     To wind as many tapes or yarns as possible to packages with one device, the winding positions are arranged in a plurality of horizontal rows, one below the other along the long side of the machine. The yarn guides associated to the winding positions for distributing the tapes or yarns extend above the uppermost horizontal row, so that a deflection of the yarn guide bar with the web of tapes or yarns does not affect the distribution to the individual winding positions. 
     In the cases, wherein the winding positions extend along two long sides of the machine that adjoin in mirror symmetry, a movable yarn guide bar is associated according to the invention to each long side of the machine. This permits doffing packages in winding positions on one long side of the machine independently of the takeup positions of the adjacent long side of the machine. 
     Preferably, the yarn guide bars are moved independently of each other by means of separate drives at a uniform guiding speed. 
     In a particularly advantageous further feature of the invention, each winding position is provided with a compensating arm control for purposes of winding the tapes or yarns to a package under a substantially constant tension. Thus, in the winding positions, a change in the tension caused by the different looping in the deflected position of the yarn guide bar, is completely controlled, so that the package can be wound under the same tension. 
     To ensure an undisturbed advance of the web of slit-film tapes in the components of the extrusion line upstream of the takeup device, a further advantageous feature of the invention comprises a depressor arranged upstream of the yarn guide bar. The depressor guides the web of slit-film tapes in a plane, which enables an undisturbed advance from upstream machine components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following, further advantages of the invention are described in greater detail with reference to several embodiments and with reference to the attached drawings, in which: 
     FIG. 1 is a schematic view of an extrusion line for producing slit-film tapes with the apparatus of the present invention; 
     FIGS. 2.1 and  2 . 2  are schematic top views of a first embodiment of the apparatus according to the invention; 
     FIGS. 3.1 and  3 . 2  are schematic side views of the embodiment of the apparatus according to the invention as shown in FIGS. 2.1,  2 . 2 ; and 
     FIG. 4 is a schematic view of a further embodiment of the apparatus according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In a film tape extrusion line as shown in FIG. 1, an extruder  1  is provided for melting a granular plastic. One outlet end comprises a special extrusion die  2 , which extrudes a film  3  that may advance into a quench bath  4  downstream thereof, where the film  3  solidifies on its surface. A feed system  5  advances the endless film  3  to a slitter  6 . In the slitter  6 , individual cutting blades penetrate the film  3 , so as to slit it into a web  7  of individual tapes. The web of slit-film tapes  7  advances parallel through a draw zone  8 , and subsequently arrives at a delivery system  9 , whence it is guided in a horizontally arranged yarn guide bar  12 . The draw zone  8  and the delivery system  9  comprise a plurality of godets. Over the circumference the godets, the web of slit-film tapes  7  loops at the greatest possible angle. In contact with the respectively last godet is a pivotally supported contact pressure roll  11 . Under the normal pressure thereof, the web of slit-film tapes  7  is pressed against the godet, and in combination with the looping, the holding and draw forces are defined. The draw zone  8  and delivery system  9  connect to a suction device  10 , which takes in the tapes during the startup of the extrusion line, i.e., during the threadup of the individual tapes. The suction device also takes in tapes that tear during the operation, so that no laps are able to form on a godet. At the end of the extrusion line, an apparatus  14  of the present invention is arranged for winding the web of slit-film tapes. At its inlet end, the takeup device  14  comprises a yarn guide bar  12 , which guides the tapes of web  7  side by side in spaced relationship for distributing them to a plurality of winding positions of the takeup device  14 . 
     In the following, the apparatus of the present invention for winding the web slit-film tapes is described in greater detail with reference to FIGS. 2.1,  2 . 2  and  3 . 1 ,  3 . 2 . FIGS. 2.1 and  2 . 2  are top views of the takeup device  14 , and FIGS. 3.1 and  3 . 2  are side views thereof. Unless explicitly referred to, the following description applies in like manner to FIGS. 2.1,  2 . 2  and  3 . 1 ,  3 . 2 . 
     One long side  18  of the apparatus mounts on a machine frame  33  a plurality of winding positions  15  side by side in the horizontal direction, and one below the other in the vertical direction. One horizontal row shows six winding position  15  in side-by-side relationship. In one vertical row, four winding positions  15  overlie one another. The number of the winding positions is exemplary both in the horizontal row and in the vertical row. For example, it is also possible that only three or two winding positions are arranged on top of one another. Likewise, it is possible to extend the horizontal row by additional winding positions. 
     In each winding position  15 , a tape is wound to a package  16 . The package  16  is produced on a driven winding spindle  17 , which mounts a winding tube for receiving the package  16 . The rotational speed of the winding spindle  17  is controlled by means of a compensating arm control  29 . In so doing, the tape is wound under a substantially constant tension at a uniform circumferential speed of the package. Above the winding positions, a plurality of yarn guides  13  extends in a distribution plane, with one of the yarn guides  13  being associated to each winding position  15 . The yarn guides  13  of one vertical row are held by a vertical support  30 . The yarn guide bar  12  is arranged upstream of the yarn guides  13 . For each slit-film tape of the web  7 , the yarn guide bar  12  comprises one yarn guide  24 , which guides the tapes of the web  7  in a horizontal plane. The yarn guide bar  12  extends substantially crosswise to the direction of advance of the web of slit-film tapes  7 . At its end facing the drive side of the winding positions  15 , the yarn guide bar  12  is mounted for pivotal movement in a pivot bearing  21 . The pivot bearing  21  facilitates a pivotal movement of the yarn guide bar  12  crosswise to the direction of the advancing web of film tapes  7  in the direction above the winding positions  15 . To perform the pivotal movement a drive  20  engages the underside of the yarn guide bar  12 . The drive  20  is designed and constructed as a cylinder-piston unit, which is activatable via a controller  31 . 
     Parallel to the long side  18  of the machine, an overhead conveyor  22  extends above the winding positions  15 . The overhead conveyor  22  mounts a package manipulator  23 , which can be moved by manual operation on the overhead conveyor  22  along the long side  18  of the machine for removing full packages from the winding positions  15 . The guide plane of the package manipulator  23  is referred to as a doffing plane, which extends parallel to the long side  18  of the machine. In the doffing plane, the package manipulator  23  can be moved horizontally and vertically for removing full packages from the winding positions  15 . 
     The slit-film tapes of web  7  are distributed to the winding positions  15  by the yarn guide bar  12  and yarn guides  13  upstream of the winding positions  15  in such a manner that the rear tapes of web  7  are guided to the winding positions  15  of the first vertical row. The additional tapes of web  7  are guided, one after the other, to the additional winding positions  15 , so that the front tapes of web  7  reach the winding positions  15  of the last vertical row. In this connection, the web of film tapes  7  extends in a distribution plane beyond the long machine side  18  of the apparatus, so that the web of film tapes  7  extends through the doffing plane. This situation corresponds to the normal operating position, in which the slit-film tapes of web  7  are each wound to a package  16 . This situation is shown in FIGS. 2.1 and  3 . 1 . 
     When the packages  16  on the individual winding spindles  17  reach their proposed size, a package doff will become necessary. At this point, the packages have, for example, a weight of more than 20 kg. Therefore, a package doff will require an auxiliary means for removing and transporting the full packages. Since such takeup devices are normally designed for manual operation, it is preferred to use as an auxiliary means a package manipulator  23 , as shown in FIGS. 2.1;  2 . 2 ;  3 . 1 ; and  3 . 2 . An overhead conveyor  22  moves the package manipulator  23  in a doffing plane parallel to the long side  18  of the machine. To release the doffing plane, which is traversed by the web of slit-film tapes  7  in the operating position, the controller  31  activates the drive  20  for purposes of deflecting the yarn guide bar  12 . In this connection, the drive  20  is designed and constructed such that the web of film tapes  7  is deflected slowly and free of pulls, so that the winding of the tapes can continue unimpeded in the winding positions  15 . The tension differences that develop from the changed looping of the film tapes of web  7  are controlled by the compensating arm controls  29  in the winding positions  15 . After the yarn guide bar has reached a deflected position that is defined by drive  20 , the packages will be doffed in the winding positions  15 . In the deflected position of the yarn guide bar  12 , the doffing plane is free for guiding the package manipulator  23 , and is no longer traversed by the web of slit-film tapes  7 . For doffing a full package in a winding position  15 , the tape is first cut, taken in by the suction device, and removed to waste. Thereafter, the full package is removed from the spindle by means of the package manipulator  23  and taken away. Subsequently, the empty winding spindle receives a new tube, so that winding can continue after threading the tape. FIGS. 2.2 and  3 . 2  illustrate the situation of a deflected yarn guide bar  12 . 
     Once the packages are doffed, the controller  31  will activate the drive  20  such that the yarn guide bar  12  pivots back to its operating position and, thus, guides the web of slit-film tapes  7  in a horizontal plane. 
     To obtain during each of the different positions of yarn guide bar  12 , a safe guidance of the tapes by the yarn guides  24  mounted thereon, the yarn guides  24  are designed and constructed preferably with a guide edge partially surrounding the tape. Such yarn guides are known, for example, as pigtails, and therefore a description of such yarn guides is omitted. 
     FIG. 4 illustrates a further embodiment of an apparatus of the present invention for winding a web of slit-film tapes  7 . In this instance, the apparatus comprises a plurality of winding positions arranged in vertical and horizontal rows along two long sides  18  and  25  of the machine, which adjoin in mirror symmetry. Each long side  18  and  25  of the machine is associated to a package manipulator  23 . 1  and  23 . 2 , which travel in a doffing plane along overhead conveyors  22 . 1  and  22 . 2 . To distribute the film tapes of web  7 , each long side  18  and  25  of the machine is provided with one yarn guide bar  12  and  26 . From the yarn guide bar  12  or  26 , the tapes are distributed to the winding positions in a manner corresponding to the above described apparatus of FIGS.  2 . 1 - 3 . 2 . To this extent, the foregoing description is herewith incorporated by reference. At its one end, the yarn guide bar  12  is mounted for pivotal movement in pivot bearing  21 , and the yarn guide bar  26  is mounted likewise for pivotal movement in a pivot bearing  32 . Each yarn guide bar  12  and  26  is associated with its own drive (not shown). The drives may be controlled independently of each another. 
     Between the yarn guide bars and a last godet  28  of a draw zone, a depressor  27  is provided. The depressor  27  remains unchanged in its position during the winding of the packages and during the doffing of the packages. Thus, the changed looping of the web of film tapes  7  on godet  28 , which is caused by the deflection of the yarn guide bar, remains without effect. In addition, the depressor  27  prevents the two parallel guided webs of the slit-film tapes from interfering with each other. 
     Since the deflection of the yarn guide bar for deflecting the web of slit-film tapes  7  out of the distribution plane for doffing the packages is identical with the embodiment of FIGS.  2 . 1 - 3 . 2 , the foregoing description is herewith incorporated by reference. In this connection, it is possible to pivot the yarn guide bars simultaneously, so that the packages can be doffed on both long sides of the machine. However, it is also possible to deflect the yarn guide bars independently of each other, so that it is possible to operate respectively only the winding positions of one long side of the machine. 
     In the embodiments illustrated in FIGS.  2 . 1 - 4 , a web of slit-film tapes is wound to packages. However, the embodiments are also suitable for winding without modification a web of yarns or other strandlike materials. The concept of the invention is independent of the material being wound. Essential is the movement of the yarn guide bar for releasing a doffing plane. The movement may also be performed by displacing the yarn guide bar in a guide rail. In so doing, it is necessary that the change in the looping always facilitate a satisfactory winding of the tapes.