Abstract:
The present invention is directed towards an improved method for delivering a continuous strip material to a spool upon which it is to be wound. The method includes the step of reducing the effective width of the continuous strip material prior to its being wound on the spool by shaping the strip material into an arcuate cross-section. The shaping means is rotatable about an axis parallel with the axis of the spool. The method includes moving the shaping means axis of rotation while winding the strip material on the spool and maintaining the shaping means axis of rotation parallel with the spool.

Description:
FIELD OF THE INVENTION 
     The present invention is directed toward a method and apparatus for storing strip material. More specifically, the present invention is directed towards a method and apparatus for positioning a continuous strip of material onto a spool. 
     BACKGROUND OF THE INVENTION 
     The present discussion is directed specifically towards the manufacture of strip material for building tires; however, the background art and the disclosed invention may also be applicable to other types of manufacturing wherein it is necessary to store strip material. 
     When forming a strip component, it may be desired to store the component in a manner that prevents the destruction or alteration of any preformed cross-sectional configuration. This is frequently accomplished by storing the component in a spiral spool storage device. The component is placed on a liner that is spirally wound inside the spool. Spacing between adjacent rows of spirally wound liner prevents the adjacent layers of wound material from contacting, thus preserving the preformed cross-sectional configuration of the strip component. 
     U.S. Pat. No. 5,412,132, JP 61-111261, and EP 621,124 illustrate such storage devices. U.S. Pat. No. 5,641,132 discloses a spool with stepped flanges wherein a liner of increasing width rests on the stepped flanges to support the component within the spool storage device. JP 61-111261 discloses a spool formed with protrusions for the edges of a liner to rest upon. EP 621,124 discloses a spiral spool storage device wherein the edges of the liner rest in continuous spiral grooves formed on the inner face of the spool flanges. 
     Because the space provided for the edges of the liner are of a relatively small dimension, the liner must be precisely fed to the storage spool. JP 61-111261 discloses first feeding the liner through a fixed metal plate. The plate has an arcuate shape with flanged sides causing the plate to have a width less than the width of the liner. The liner is fed through the plate, inside the flanges, reducing the effective width of the liner. After the liner passes through the plate, the liner is feed onto the spool. The liner returns to its original width after once it is placed onto the spool, known in the art as the liner “popping” into place. 
     EP 621,124 also teaches reducing the effective width of the liner prior to feeding it into position on the spiral spool. Three different methods of reducing the liner width are disclosed. Two methods employ the use of curved bars through which the liner passes. The curved bars are in a fixed angular relationship with the rod upon which the bars are attached. The third method disclosed employs two pairs of deflecting bars. The first pair initially deflects the edges of the liner and the second pair slides relative to the spiral spool to ensure proper positioning of the liner onto the spool. 
     While the above methods accomplish the goal of delivering the liner to the spiral spool, these methods require precise placement of the liner to prevent the liner from popping out of place, and to prevent folding and creasing. When such problems do occur with the liner, the continuous manufacturing of the component must be stopped to resolve the problem. The present invention is directed to a method of delivering the liner to the spiral spool in a manner and by an apparatus which overcomes these limitations and issues of the known delivery systems. 
     SUMMARY OF THE INVENTION 
     The present invention is directed towards an improved method for delivering a continuous strip material to a spool upon which it is to be wound. The method includes the step of reducing the effective width of the continuous strip material prior to its being wound on the spool by shaping the strip material into an arcuate cross-section. The shaping means is rotatable about an axis parallel with the axis of the spool. The method includes moving the shaping means axis of rotation while winding the strip material on the spool and maintaining the shaping means axis of rotation parallel with the spool. 
     A further aspect of the invention includes moving the shaping means axis of rotation in a vertical direction. 
     In another aspect of the invention, the shaping means includes multiple sets of rollers that interact to reduce the effective width of the strip material. The shaping means may also be defined by a fully enclosed slot, which maintains the reduced effective width of the strip material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described by way of example and with reference to the accompanying drawings in which: 
     FIG. 1 illustrates an apparatus for winding a strip component; 
     FIG. 2 illustrates the spiral spool as the strip component and liner are being wound thereon; 
     FIG. 3 is a cross-sectional view of the spiral spool along line  3 — 3  of FIG. 2; 
     FIG. 4 is a perspective view of the pre-former; 
     FIG. 4A is a top view of the pre-former; 
     FIG. 4B is a bottom view of the pre-former; 
     FIG. 5 illustrates the pre-former; 
     FIG. 6 illustrates the liner delivery system; and 
     FIG. 7 illustrates a second embodiment of the pre-former. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIG. 1, an apparatus, incorporating the present invention, for winding and storing a strip component is illustrated. The apparatus is comprised of a spool  4  in which the strip component  10  is wound, a let-off means  6  for the strip component  10 , and a delivery system  8  for the liner  12  upon which the strip component  10  is to be placed. The spool  4  is mounted on an axle  14  coincident with the axis of the spool  4  and upon which the spool  4  rotates. As the spool  4  rotates, the liner  12  is fed from one side of the spool  4  from a liner spool  13 , while the strip component  10  is then laid upon the liner  12  from the other side of the spool  4 . The strip component  10  can be unvulcanized elements of a tire, such as sidewalls, tread, apex, or other strip materials that could be susceptible to crushing in conventional storage mechanisms. 
     The spool  4  has first and second flanges  16 ,  18 , see FIG.  3 . Each of the flanges  16 ,  18  has an axially outer surface  20  and an axially inner surface  22 . The axially inner surfaces  22  of the first and second flanges  16 ,  18  each have a continuous spiral groove  24 . The grooves  24  are adapted to receive the edges  26  of the liner  12 . The grooves  24  have a radius creating a radial distance between the adjacent turns of each groove  24  that is greater than the combined thickness of the liner  12  and the strip component  10  to be wound into the spool. The radially inner surface  28  of each groove  24  is beveled downwards toward the central axis of the spool  4 . In a preferred construction, the radially inward surface  28  is beveled so that it makes an angle of about 10° with a line parallel to the axis of the spool  4 . The purpose of the beveling is to facilitate insertion and removal of the liner edges  26 . 
     The liner  12  has a sufficient width to extend between the spool flanges  16 ,  18  and permit the liner edges  26  to rest within the spiral grooves  24 . The liner  12  must be formed of a strong enough material so that the weight of the strip component  10 , when wound into the spool  4 , does not cause the liner  12  to deflect and contact or crush the component  10  stored upon radially inner windings of the component  10  and liner  12 . Preferred materials for the liner  12  include rigid polyethylene terephthalate, polypropylene, and other similar materials. 
     The spool  4  is also defined by a series of openings  30  in the axially outer surfaces  20  of the flanges  16 ,  18 , see FIG.  2 . Because the strip component  10  is preferably loaded onto the spool  4  directly from an extruder, it is still hot and in various stages of curing. The openings  30  of the spool  4  permits air to flow back and forth through the openings  30  and over the strip component  10 . 
     As previously discussed, for proper delivery of the liner  12  to the spool  4 , it is desired to reduce the effective width of the liner  12 , i.e. shaping the liner  12  into an arcuate cross-sectional configuration. This is accomplished within the liner delivery system  8  which incorporates a pre-former  32  mounted on a pair of Thomson rails  34 ; the Thomson rails  34  permit the pre-former  32  to travel vertically. The pre-former  32  is mounted to the Thomson rails  34  by means of the bearing box  50 . The bearing box  50  is provided with an internal bushing. The bushing allows the pre-former  32  to pivot freely about a longitudinal axis  35 , enabling the pre-former  32  to remain in a perpendicular alignment to the liner  12  as the liner  12  passes through the pre-former  32 . The pre-former  32  is the shaping means which shapes the liner  12  into the desired arcuate cross-sectional configuration. 
     In one embodiment, the pre-former  32  has three sets of interacting rolls  36 ,  38 ,  40  mounted on end frames  42 , see FIGS. 4,  4 A,  4 B,  5 . The sets of rolls  36 ,  38 ,  40  interact to shape the liner  12  to a desired curved configuration prior to insertion of the liner  12  in the spool  4 . The first set of rolls  36  can be defined as upper deflection rolls, the second set of rolls  38  are edge deflection rolls, and the third set of rolls  40  can be defined as underside support rolls. 
     The set of upper deflection rolls  36  is mounted on an axle  44  and has at least two different sized rolls  46 ,  48 . A center roll  46  has the greater relative diameter and two smaller diameter rolls  48  are mounted on the axle  44  at equi-distances from the center roll  46 . The rolls  46 ,  48  are mounted on bearings to rotate about the axle  44 . The axle  44  through each end frame  42  and into a bear box  50 . The axle  44  rests in the internal bushing of the bearing box  50 . This configuration of the set of upper deflection rolls  36 , in conjunction with the second and third set of rolls  38 ,  40 , bows the bows the liner  12  as it passes beneath the set of deflection rolls  36 , reducing the effective width of the liner  12 . 
     There are two sets of edge deflection rolls  38 , one set  38  attached to each end frame  42 . Each set of edge deflection rolls  38  is preferably comprised of two different sized rolls  52 ,  54 . There is a single short center roll  52  and two long outer rolls  54 . The center roll  52  is aligned with the axle  44  of the first set of rolls  36 , and is preferably inclined at an angle relative to the axle  44 . The long rolls  54  extend at an angle relative to the axle  44  of the first set of rolls  36 , in an opposing direction from the short roll  52 , and are attached to the associated end frame  42  adjacent the short roll  52 . The rolls  52 ,  54  are mounted on bearings so that each roll  52 ,  54  may rotate along its longitudinal axis as the liner passes through the pre-former. The short rolls  52  restrain the vertical and horizontal movement of the liner edges  26  and the long rolls  54  support the liner  12  from underneath to maintain the arcuate liner configuration. 
     The set of underside support rolls  40  is mounted on an axle  56  extending between the end frames  42 . The set  40  is comprised of two identical rolls  58  equi-spaced from the centerpoint of the axle  56 . The axle  56  is mounted on the same long axis of the end frames  42  as the first set axle  44 . The rolls  58  have a conoid configuration, wherein the greatest diameter of the rolls  58  faces the end frames  42 . The rolls  58  are mounted on bearings to permit rotation about the axle  56 . Preferably, to provide consistent support for the liner  12 , the outer surface of the rolls  58  are directly adjacent to the outer surface of the long rolls  54  of the second sets  38 . If needed, a small roll may be mounted centrally between the two rolls  58  to support the underside of the centermost point of the liner  12 . 
     It would be appreciated by those in the art that while a particular roll combination and construction has been disclosed, other roll may be substituted for the disclosed rolls so long as a desired trough shaped path is maintained for the liner  12  to travel through when passing through the pre-former  32 . 
     As noted above, axle  44  extends through the end frames  42  and into a bearing box. The bearing box permits the pre-former  32  to pivot about the longitudinal axis  35  of the axle  44 , see FIGS. 1 and 6, as the pre-former  32  travels up and down the Thomson rails  34 . The bearing box  50  is provided with an internal bushing. The axle  44  rests in the bushing. The bushing allows the axle  44  to freely pivot about the longitudinal axis  35  of the axle  44 , enabling the pre-former  32  to remain in a perpendicular alignment to the liner  12  as the liner  12  passes through the pre-former  32 . It is the stiffness of the liner  12  as it passes through the pre-former  32  that causes the pre-former  32  to pivot. The pre-former  32  also travels the Thomson rails  34  in order to maintain alignment of the liner  12  coming out of the pre-former  32  with the location where the liner  12  is fed onto the spool  4 . This permits a smoother transition of the liner  12  from the liner spool  13  to the storage spool  4 . Thus, during operation of the liner delivery system  8 , the pre-former  32  moves in two different directions about two different planes. The pre-former  32  rotates about a single axis  35 , parallel to the axis of the spool  4 , and travels vertically along the Thomson rails  34 . It is this combination of movement that maintains the liner  12  in the desired delivery configuration and orientation to the spool  4 , and permits the liner  12  to be properly delivered into the storage spool  4 . 
     Adjacent to the spool  4  is a set of deflecting bars  60  mounted on a sliding platform  62 . The sliding platform  66  is translatable along a rail  64  that is mounted to a base  68  of a frame upon which the spool  4  is mounted. The deflecting bars  60  have a bend  70  near their midpoint that is designed to accommodate the limitations of existing equipment. Should new spools, frames, and let-offs be configured to implement the apparatus, this bend  70  will no longer be necessary. The purpose of the sliding platform  62  is to adjust the deflecting qualities of the deflecting bars  60  as the spool  4  fills with liner  12  and strip component  10 . When the spool  4  is nearly empty, the deflecting bars  60  are fairly close to the axle of the spool  4 . As the spool  4  rotates and becomes filled with liner  12  and strip component  10 , the deflecting bars  60  slide radially outwardly away from the axis of the spool  4 . 
     With reference to FIGS  1  and  3 , the method by which the liner  12  and strip component  10  is loaded onto the spool  4  will be described. When the spool  4  is empty and being prepared for storing strip material  10 , about one revolution of the end of the liner  12  is wrapped around the core  72  of the spool  4  and secured thereto by means such as hook and loop strips  74 . The edges of the liner  26  are initially threaded into the first opening of the groove  24 . Once the liner  12  has been correctly threaded into the groove  24 , it follows the spiral pattern of the groove  24  and thus continues to be threaded into the entire spool  4  as the liner edges  26  are pulled into the groove  24 . As the spool  4  rotates 180°, a newly extruded strip of strip component  10  is laid on the radially outward surface  76  of the liner  12 . The process continues with the spool  4  rotating and loading liner  12  and strip component  10  into the spool  4  in a spiral fashion until the spool  4  is full. 
     An alternative embodiment of the pre-former  32 ′ is illustrated in FIG.  7 . The pre-former  32 ′ is formed from a single block  78  of lightweight material. A slot  80  corresponding to the desired curvature, i.e. reduced effective width, of the liner  12  is cut into the block  78 . Mountings  82  are provided at each end of the block  78  so that the pre-former  32 ′ may be attached to the bearing boxes  50 . The pre-former  32 ′ operates similar to pre-former  32 , in that, due to the internal bushings in the bearing boxes  50 , the pre-former  32 ′ may rotate about a longitudinal axis  35 , parallel to the axis of the spool  4 , to maintain a perpendicular relationship with the liner  12 . While the block  78  is illustrated as a rectangular element, it would be appreciated that the longitudinal edges  84  of the block  78  may be smoothed down to more approximate a cylindrical or tubular configuration. 
     Mounted above the block  78  is at least one roll  86 . Illustrated is a pair of rolls  86  mounted to side plates  88 . The rolls  86  are mounted so that they freely rotate. These rolls  86  are employed when the strip component  10  is delivered to the spool  4  from the same side of the spool  4  as the liner  12  and guides the strip component  10  over the pre-former  32 ′. In such a delivery method, the liner  12  passes through the pre-former  32 ′ while the strip component  10  travels above the pre-former  32 ′. For the embodiment illustrated in FIGS. 3-6, the strip component  10  may travel over the center roll  46 , or the pre-former  32  may be provided with a separate roll, or other similar apparatus, mounted over the pre-former  32  to guide the strip component  10  over the pre-former  32 . 
     The dual movement of the pre-former  32 ,  32 ′ permits the liner  12  to be delivered to the spool  4  in a more consistent configuration as the liner  12  need not travel any extended distance where the arcuate configuration may be altered, and places less stress and tension on the liner  12 . This increases the liner life, reducing manufacturing down time, and improves the accuracy of the placement of the strip component  10  laid upon the liner  12  which in turn improves the uniformity of the final manufactured product into which the strip component  10  is assembled. Also, the delivery system  8 , and the pre-former  32 ,  32 ′ is easier to load than conventional pre-formers due to the compact size. This also reduces the manufacturing down time, and increases the liner life. 
     Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full-intended scope of the invention as defined by the following appended claims.