Abstract:
An apparatus and method is disclosed for winding a web about a central axis and a rotating mandrel to form a roll. A feeding mechanism provides a running web to be wound into a roll. A retainer assembly may be configured for holding the web as it is wound upon the rotating mandrel. The retainer assembly may be configured to accommodate oscillating movement of the rotating mandrel between a clockwise and a counterclockwise direction. The web may be wound in one direction and then back again repeatedly to form a roll. Retaining means, such as paddles, may be actuated from an active position in contact with the web to a resting position removed from the roll. Paddles may serve to hold the web upon the outer surface of the roll at the time in which the rotating mandrel is changing rotational direction.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
         [0001]    This patent application relates to another application entitled ROLLED WEB PRODUCTS HAVING A WEB WOUND IN AN OSCILLATING FASHION by Lake et al. which was filed Dec. 22, 2001.  
         BACKGROUND OF THE INVENTION  
         [0002]    Various manufacturing operations engage in winding web material around a central core. Such winding is employed to manufacture a host of products that are made for use in modern society, including tape, plastics, cording, nonwoven materials and the like.  
           [0003]    Natural and synthetic textiles, nonwoven materials, and coform materials may be manufactured in a first process to produce bulk materials, and then stored for later use in a second process. For example, such material may be wound upon spools or cores for temporary storage in relatively large quantities until the bulk material is needed to manufacture products. For example, many consumer and disposable absorbent products are manufactured in a first process, and then spooled on large spools while they await a subsequent manufacturing process. In manufacturing, the spools may be removed from storage and then transported to a location where they are needed, and then placed into a manufacturing line for use. Such web materials may be fed from the spool into the manufacturing operation.  
           [0004]    One problem encountered when unwinding elongated web material from spools or rolls is undesirable twisting of the web as it uncoils when the roll is kept in a stationary position. Various methods have been attempted to avoid twisting, which can lead to problems in manufacturing. Twisting may occur when a core or spool is placed upright on a level surface, with the core oriented vertically, and such materials are pulled or fed from the core in a direction that is not in alignment with the core or spool. Some manufacturing operations in the past have relied upon driven unwind systems to assist in such operations. However, such systems consume energy and require maintenance.  
           [0005]    Some processes have employed continuous strips of material in a technique known as “festooning” in which the strip is folded back and forth to lay a series of strip portions, with each portion being folded relative to the next about a line transverse to the strip. The technique of festooning has been used for some time and is employed in the manufacture of packaging materials including nonwovens, fabrics, and the like. The strip may be guided into a cardboard box, or may be rolled into a cylindrical pad, as examples. International Patent Application Publications WO 99/59907 and WO 99/16693 illustrate such methods.  
           [0006]    What is needed in the industry is a method of winding large volumes of material in a manner that makes the material available for unwinding at a later time in a convenient and ready format. A method of winding such materials in a manner that will avoid or minimize twisting of the material is desirable. Furthermore, a method or assembly that provides an opportunity to make and deploy multiple spools or rolls in succession without stopping to reload rolls would be helpful. Furthermore, a system that enables utilization of rolls without using a conventional driven unwind system would be quite useful.  
         SUMMARY OF THE INVENTION  
         [0007]    The invention may include a method of winding a material around a central core, using an apparatus that is capable of oscillation. An apparatus is provided for winding a web around a central axis to form a roll. The apparatus may include a rotating mandrel oriented along the central axis, and a feeding mechanism including at least one roller for holding in a feed position a running web to be wound upon the rotating mandrel.  
           [0008]    Furthermore, a retainer assembly may be mounted around the central axis of the mandrel. The retainer assembly may be provided to accommodate oscillating movement of the rotating mandrel and roll, between a clockwise and counter clockwise direction. The retainer assembly may provide support to the outer portion of the roll during winding of the web upon the rotating mandrel in forming the roll. The retainer assembly may have at least one circumferential support stay for engagement of the web on the outer surface of the roll as the roll is built.  
           [0009]    In some applications of the invention, a retaining means may be used to support the outer portion of the roll during winding of the web upon the rotating mandrel. A feeding means sometimes may be employed to hold in a feed position a running web to be wound upon the rotating mandrel.  
           [0010]    The invention may provide a method for winding a web to form a roll. The method may include steps such as providing a mandrel along an axis, and then feeding a web through a feed assembly for winding the web upon a rotating mandrel. Furthermore, a retainer assembly may be provided in operable connection to the rotating mandrel. The retainer assembly (or retainer means) may serve to preserve the web in position during rotation of the mandrel and roll. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    A full and enabling disclosure of this invention, including the best mode shown to one of ordinary skill in the art, is set forth in this specification. The following Figures illustrate the invention:  
         [0012]    [0012]FIG. 1 is a front view of the winding apparatus in the counter clockwise mode or position;  
         [0013]    [0013]FIG. 2 shows a rear view of the winding apparatus, also in the counter clockwise position;  
         [0014]    [0014]FIG. 3 depicts a second front view of the winding apparatus in the counter clockwise position, in which the mandrel has advanced or rotated towards the left in the Figure;  
         [0015]    [0015]FIG. 4 is a view of the assembly in the clockwise position or mode; and  
         [0016]    [0016]FIG. 5 shows a rolled web product manufactured using the winding apparatus shown in FIGS. 14;  
         [0017]    [0017]FIG. 6 shows a second embodiment of a rolled web product;  
         [0018]    [0018]FIG. 7 is a schematic cross sectional view of a coreless rolled web product, showing how web is overlapped and is wound in both a first and second direction, in alternating sequence;  
         [0019]    [0019]FIG. 8 is another schematic showing how the overlap point may move about the periphery of the web as the web is wound;  
         [0020]    [0020]FIG. 9 shows a later point in the winding, when the web winding direction has been reversed; and  
         [0021]    [0021]FIG. 10 shows a cross-section of a multiple “stacked” roll assembly that can be manufactured in the practice of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Reference now will be made to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not as a limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in this invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment.  
         [0023]    The term “web material” or “web” as used herein refers to a sheet-like material or to a composite or laminate comprising two or more sheet-like materials. For example, such materials may include a fibrous web, a non-fibrous web, a nonwoven web, a film, a plastic film, a non-plastic film, a foam, tape, cording, textiles, rope, and tubing. Such webs or web materials may be supplied to the manufacturing process along the longitudinal dimension. Accordingly, the material may be rendered virtually infinite in the longitudinal dimension by splicing together a plurality of stretches of web material, or a plurality of rolls.  
         [0024]    The apparatus and method of the invention may include the winding of a web or other material around a central core wherein the material is wound in an oscillating fashion. However, a core is not always required, as further discussed herein.  
         [0025]    The web or web material may be wound in any amount, such as from about 1 to about 3 revolutions in one direction, and then the winding direction is reversed for several more revolutions, and repeated to wind a running web into a roll. In practice, the overlapped tail of the web in each revolution may be secured to the overlapped tail of the web in a previous revolution to hold the web and prevent it from unraveling during the winding process. The winding process may be repeated until the desired roll diameter is obtained. The application of the method and apparatus of the invention makes it possible to minimize the amount of twist generated in the final product or roll when the roll is unwound from a stationary position in manufacturing operations, as further described herein with reference to FIGS.  5 - 10 .  
         [0026]    The winding of the web may occur upon a core, or alternatively upon a collapsible airshaft. The amount of overlap employed between directional changes may be subject to web material response and footprint, and the distance required to enter the material in the converting process without an undesirable twist.  
         [0027]    In one particular embodiment of the invention, the web is wound approximately 370-720 degrees in a clockwise direction, and then wound again 370-720 degrees in a counter clockwise direction, and repeated. The amount of overlap may be varied, and will depend upon the material to be wound, and the ultimate use for the roll. Furthermore, the overlap as described may be moved about the radius of the roll, during winding, by changing the location of the overlap as the roll is built. In practice, changing the location of the overlap sometimes prevents a double material thickness at the overlap, thereby avoiding a roll that is undesirably out of round.  
         [0028]    Turning now to FIG. 1, a winding apparatus  20  is shown which feeds a running web  21  upon a mandrel  22  that is located along a central axis. A cleavage roll assembly  23  directs the application of the web  21  upon the roll  27 . The web  21  is passed to the first cleavage roll  24  and a second cleavage roll  25 . A support structure  26  is capable of controlling the position of first cleavage roll  24  and second cleavage roll  25 . The cleavage roll assembly  23  therefore may include a first cleavage roll  24 , a second cleavage roll  25 , and a support structure  26 .  
         [0029]    A stationary retainer assembly  35  is mounted around the central axis of the mandrel  22 , and is configured for accommodating oscillating movement of the roll  27  between a clockwise and counter clockwise direction. In FIG. 1, the web  21  is passed underneath the first idler roll  29  to the roll  27 . A counter clockwise direction assist paddle  32  is shown in FIG. 1 in the active position in which the counter clockwise directional assist paddle  32  is extended to enable it to contact and retain the web  21  upon the outer surface of the roll  27 . It should be recognized that the directional assist paddles  31 - 32  may be provided in any mechanical configuration, and therefore they may be flat, oblong, spherical, or multi-lobed. In some applications, only one such paddle may be required. The Figures represent one configuration having relatively flat directional assist paddles  31 - 32 , but there are numerous shapes that could be employed in the practice of the invention.  
         [0030]    A second idler roll  30  is also seen in FIG. 1. The second idler roll  30  controls the position of the second circumferential support stay  34 . The first idler roll  29  controls the position of the first circumferential support stay  33 . The first circumferential support stay  33  and the second circumferential support stay  34  work in tandem on each side of the roll  27  to retain the web  21  upon the roll as the roll  27  is building in size. The clockwise direction assist paddle  31  is shown in FIG. 1 in the retracted position.  
         [0031]    The cleavage roll assembly  23  is typically capable of switching between two or more different modes. In the dual mode, a first position of the cleavage roll assembly  23  as shown in FIG. 1 may provide an air cylinder  44  which has been activated along rod  45  to push the bar  46  into notch  47  of the support structure  26 . This activation enables the web  21  to pass in the appropriate direction between the first cleavage roll  24  and the second cleavage roll  25 , as shown in FIG. 1. Support frame  38  holds the support structure  26  in position.  
         [0032]    The clockwise direction assist paddle  31  is activated along rod  43  by air cylinder  41 . The counter clockwise direction assist paddle  32  is activated along rod  42  by air cylinder  40 .  
         [0033]    In the process of winding a roll  27 , the rotation of the mandrel  22  in a counter clockwise direction is halted. The clockwise directional assist paddle  31  extends to contact web  21  and introduces the web  21  into a nip area which is created by second idler roll  30  and roll  27 . The mandrel  22  then begins to rotate clockwise, which may continue until the web  21  begins feeding between the roll  27  and second circumferential support stay  34 , upon which the clockwise directional assist paddle is retracted.  
         [0034]    The retainer assembly  35  receives support from control arms  37   a - d , as shown in FIG. 2. FIG. 2 shows a rear view of the winding apparatus  20 . In FIG. 2, the mandrel has been rotated so that the web  21  is proceeding into the roll  27  from a direction that is generally parallel to the support frame  38 . The support frame  38  holds in position the cleavage roll assembly  23  and the directional assist paddles  31 - 32 .  
         [0035]    In FIG. 2, a control arm guide member  50  including channels  49   a - b  is shown. Bolt  51  and bolt  52  are connected, respectively, to control arms  37   b - c  and control arms  37   a  and  37   d  as shown in FIG. 2. The movement of bolt  51  upwards and bolt  52  downwards allows the size of the roll  27  to expand. In that way, the control arms  37   a - d  articulate with each other to facilitate a change in size of the roll  27  as the winding process proceeds.  
         [0036]    [0036]FIG. 3 shows a front view of the winding apparatus  20  that was seen in FIG. 2. In FIG. 3, the counter clockwise directional assist paddle  32  has been activated by the air cylinder  40  along rod  42  to an active position. Also, in FIG. 3, the clockwise direction assist paddle  31  has been retracted by movement of air cylinder  41  along rod  43  away from the roll  27 . A roller  54  is shown in position to retain the first circumferential support stay  33  upon the upper surface of the roll  27 . A roller  55  is shown in position to retain the second circumferential support stay  34  upon the lower path of the roll  27 , as shown in FIG. 3.  
         [0037]    As the winding assembly  20  shifts from a counter clockwise mode into a clockwise mode, several adjustments are made. As shown in FIG. 4, the winding apparatus  20  now has assumed a clockwise mode in which the counter clockwise directional assist paddle  32  has been retracted, and the clockwise directional assist paddle  31  has been extended. Furthermore, as seen in FIG. 4, web  21  now feeds from a different direction, through the first cleavage roll  24  and the second cleavage roll  25 . Adjustment of the first cleavage roll  24  and second cleavage roll  25  has occurred by the actuation of air cylinder  44 , which extends rod  45  to move bar  46  into notch  47 , resulting in movement of the first cleavage roll  24  and second cleavage roll  25  to the position shown in FIG. 4. In that position, the web  21  now is prepared to wind upon the rotating mandrel  22  in the clockwise direction, with the clockwise direction assist paddle  31  extended to contact the surface of the roll  27 . This contact holds the web  21  in position during a change in oscillation of the winding apparatus  20 .  
         [0038]    The invention is not limited to the use of such paddles to retain the roll  27  at each end of the oscillation. For example, other methods could be used to secure overlapping layers of the web  21  during winding of the roll  27 . These methods include, but are not limited to, the use of adhesives, thermal bonding, ultrasonic techniques, or mechanical bonding methods. For example, an adhesive could be sprayed upon the web  21  at each end of the oscillation cycle, at about the point at which the web  21  reverses direction.  
         [0039]    In the practice of the invention, the opportunity exists to lay several oscillated rolls (such as roll  27 ) on top of each other, in succession. That is, it is possible to attach the inner tail of an expiring roll to the outer tail of a new roll to provide a stack of rolls which are interconnected. Such an arrangement would permit the rolls, when they are later used, to unwind in succession. That is, multiple rolls could be wound, and connected by web  21 , thereby avoiding or minimizing the need for a dynamic splice. In general, a dynamic splice refers to a splice that must be made when a roll must be replaced in the course of a manufacturing operation. Thus, a stack of rolls, or a pancake wound oscillated roll stack could be constructed, which may obviate the need to use a dynamic splice.  
         [0040]    [0040]FIG. 5 shows a sheet-like rolled web product  100  produced using the apparatus of the invention. A core  101  is used in this particular example, and a first end  102  of the web is adjacent the core  101 , while a second end  103  is shown on the outer circumferential surface of the web  104 .  
         [0041]    [0041]FIG. 6 shows a rope or cordage type of rolled web product  110  produced using the apparatus of the invention. A core  111  is provided in this particular example, and a first end  112  of the web is adjacent the core  111 , while a second end  113  is shown on the outer circumferential surface of the web  114 .  
         [0042]    In FIG. 7, one can see the method of forming overlap using the apparatus of the invention. This particular example shows a coreless rolled web product  120 . The web is positioned upon the outer surface of the center air space  130  in a manner whereby the web  121  is positioned in a first direction, and also in a second and opposite direction, in alternating sequence, from the first end of the web to the second end of the web.  
         [0043]    The web  121  is wrapped upon the core in a pattern resulting from oscillating revolutions about the core, in which a first tail  124  (or first overlap) is formed upon the web  121  at a point corresponding to the directional change. A second overlap or second tail  125  is formed in the next revolution, and third overlap or third tail  127  in the next, and fourth overlap or fourth tail  129  in the next (see FIGS.  7 - 9  as well). Each successive tail is secured in an overlapping manner to the tail of the web  121  from a previous revolution.  
         [0044]    In FIG. 7, a first paddle  123  is extended to contact web  121  to hold it while a directional change to counter clockwise direction  122  is made. FIG. 8 shows the rolled web product  120  reversing to proceed again in the clockwise direction  128 , with second paddle  126  extended to hold third tail  127  in position to prevent undesirable unraveling as the roll builds.  
         [0045]    [0045]FIG. 9 shows first paddle  123  once more extended to hold fourth tail  129 , as the overlapping and winding process continues.  
         [0046]    An example of a stacked roll assembly  160  that can be produced according to the method of the invention as previously described is shown in FIG. 10. In FIG. 10, a stacked roll assembly  160  is shown having a first pancake roll  163  and a second pancake roll  164  stacked vertically. In general, there is no limit to the number of such pancake rolls  163 - 64  that can be stacked in forming a stacked roll assembly  160 . FIG. 5 shows one example in which two stacked pancake rolls  163 - 64  are provided, but a stacked roll assembly  160  could have as many as four, five, six or more pancake rolls stacked together. The stacked roll assembly  160  could include optional cores  161 - 62 , or in other applications it may be possible to construct pancake roll  163  and pancake  164  without cores  61 - 62 , using a removable mandrel (not shown) or an air cylinder (not shown).  
         [0047]    The stacked roll assembly  160  is shown in FIG. 10 in position to be unwound and deployed in the manufacture of products. In FIG. 10, the web  21  is pulled upwards and released from the first pancake roll  163 . Once the first pancake roll  163  is exhausted, the process continues with the tail end  165  of the web  21  being connected to the lead end  166  of second pancake roll  164 . Deployment of the stacked roll assembly  160  therefore may, in some manufacturing applications, without the necessity of stopping a manufacturing operation to insert a new roll.  
         [0048]    In some applications, it is possible to provide a shaft upon which the web  21  is wound (shaft not shown). The web  21  also could be driven through a series of friction drive rollers (not shown in FIG. 10). The web  21  could be attached to such a shaft and wound in a clockwise direction between about 1 and about 3 revolutions, then the process could be halted and a nominal amount of adhesive could be applied to the outside of the web  21 . Then, the process could continue in a counter clockwise direction until a nominal amount of web  21  passes through the adhesive application point (not shown in FIG. 10). Then, the direction can be reversed again with the web  21  moving again in the clockwise direction. In this way, the infeed material web  21  could be allowed to move upward, thereby changing the angle of web  21  orientation in reference to the building roll.  
         [0049]    It is understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. The invention is shown by example in the appended claims.