Abstract:
A method and assembly for packing a plurality of similar items of coiled material, each item having an annular shape with an internal circumferential surface of first diameter. A sheet of cardboard is folded to form a hollow cylindrical post having a triangular cross section with only three sides and three corners. The post is shaped so that an imaginary circle of second diameter drawn around the triangular cross section passes through each of the three corners, wherein the first diameter is equal to the second diameter The coiled material is sequentially positioned over the hollow post so that the internal circumferential surface of each item is in substantial contact with each of the three corners. At least two ties are positioned and tensioned to bind the items of coiled material to the post.

Description:
BACKGROUND 
       [0001]    The present invention relates to a system and method for packing coiled material such as wire, rope, hosepipe, cable, or similar items for transport and display. Specifically, the invention relates to an inexpensive and simple method for linking and displaying separate rolls of coiled material by using the structural properties of corrugated cardboard to form a support post folded in a novel and specially configured manner, and used in combination with other lightweight packaging materials. 
         [0002]    Systems and methods for transporting and displaying coiled materials are known in the art. Coiled materials such as wire, rope, cable, or hosepipe are frequently collected together for transport and/or for display, and they present specific problems that are associated with their shape. One problem is that coiled materials, which are usually bound into discrete annular configurations having the approximate shape of a tire, do not readily stack upon each other, but when attempts are made to stack them for convenient transport or display, they tend to become separated in a sliding action relative to each other so that a vertical pile or horizontal stack of coiled items tends to collapse in a heap absent structure that holds them together. Yet, even known structures that tends to hold them together suffer from drawbacks and deficiencies. 
         [0003]    For example one type of solution that has been employed is described in U.S. Pat. No. 2,916,152, U.S. Pat. No. 3,021,010, U.S. Pat. No. 3,127,018, U.S. Pat. No. 3,197,031, and U.S. Pat. No. 4,068,971. These patents all focus on stacking a pile of annular or coiled objects on an elongate post, where the post is made up of a plurality of rods welded or bound together. The post prevents the coils from collapsing, and holds them in a vertical column. However, these systems suffer from the disadvantage that the posts themselves are inconvenient to stack one upon another for storage when they are not being used. When made out of metal, they are heavy and difficult to manipulate. They are prone to being locally damaged by lateral or shear loads, and are also prone to being bent out of shape by shear loads because they lack shear reinforcing which, if provided, would require further material to be welded across the inside of the post. If this costly step were taken, it would eliminate what little stackability such posts have. Moreover, they are expensive to make as they require the input of skilled labor and costly material. 
         [0004]    Therefore, there is a need in the art for a system and method of stacking annular or coiled material that overcomes the disadvantages of the prior art. The present method addresses these and other needs. 
         [0005]    These and other advantages of the invention are described below in the detailed description of the preferred embodiments, with reference to the drawings. 
       SUMMARY OF THE INVENTION 
       [0006]    In a first preferred embodiment of the present invention, a method of packing a plurality of similar items of coiled material is described, wherein each item has an annular shape with an internal circumferential surface of first diameter. The method comprises providing a sheet of cardboard, and folding the sheet of cardboard to form a hollow cylindrical post that has a triangular cross section with only three sides and three corners. Preferably, the triangular cross section is equilateral. The triangular cross section is sized so that an imaginary circle of second diameter that is drawn around the triangular cross section passes through each of the three corners, and the first diameter (of the annular shaped items) is substantially equal to the second diameter (of the post). This configuration ensures that the post, which is eventually introduced within the coiled annular shapes, has each of its corners simultaneously in substantial contact with the internal circumferential surface of the coiled items. Thus, the method further includes sequentially positioning each item of coiled material around the hollow post so that the internal circumferential surface of each item is in substantial contact with each of the three corners. In this way, the items are stacked upon each other and are constrained against lateral movement by the post. 
         [0007]    In a further preferred aspect of the invention, the method further includes tying the post to the items of coiled material by means of at least one tie that is looped, under tension, around at least one corner of the post and also around the coiled material. Preferably, each tie is a flat strip of material. The invention may also include using at least two ties, wherein each tie extends within a corner of the hollow post, adjacent to two sides of the post, and further extends on the outside of the items of coiled material to form a loop, whereby the tie, when tensioned, compresses the items together and constrains the items against movement along the post. In another aspect of the invention, folding the sheet of cardboard includes folding a portion of a terminal end of each of the three sides of the cylindrical post to form an outwardly extending flange at a terminal end of the post. The flange provides stability to the post when the coiled items are stacked upon the post while the post is seated upon a floor. Moreover, folding the sheet of cardboard may include forming a continuous sheet of cardboard around at least two of the three corners, or it may include forming a continuous sheet of cardboard around each of the three corners. 
         [0008]    In another facet, the invention comprises an assembly of items of coiled material packed for transport, each item having an annular shape with an internal circumferential surface of first diameter. The assembly further comprises an elongate hollow post having three sides made of cardboard sheeting, the three sides intersecting in three corners so that the post has a cross sectional shape that is triangular, preferably equilateral, wherein an imaginary circle of second diameter drawn around the triangular cross section passes through each of the three corners, and further wherein the first diameter is substantially equal to the second diameter. A plurality of items of coiled material is positioned around the post so that the internal circumferential surface of each item is in substantial contact with each of the three corners. In a further aspect, the invention includes at least two ties that have the shape of a flat strip extending longitudinally along a corner of the hollow post adjacent to two sides of the post, the ties further extending on the outside of the items of coiled material to form a loop, the ties being tensioned to compress the items together and to constrain the items against movement along the post. In other preferred embodiments, there are three ties. An outwardly extending flange at a terminal end of the post is provided for stability. Moreover, at least two of the three corners of the post may extend continuously around the corners, and in a further embodiment, all three corners extend continuously around the corners. 
         [0009]    These and other advantages of the invention will become more clearly apparent with reference to the figures and the detailed description of the preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of an assembly including a post having features of the present invention, tied to and providing stability to a plurality of items of coiled material. 
           [0011]      FIG. 2  is a top view of the assembly shown in  FIG. 1 . 
           [0012]      FIG. 3  is an elevational perspective view of the assembly shown in  FIG. 1 . 
           [0013]      FIG. 4  is an side elevational view of a first embodiment of a post of the present invention, shown as a flat sheet prior to being folded. 
           [0014]      FIG. 5  is an side elevational view of a second embodiment of a post of the present invention, shown as a flat sheet prior to being folded. 
           [0015]      FIG. 6  is the post of  FIG. 4  shown in perspective in its folded condition. 
           [0016]      FIG. 7  is the post of  FIG. 5  shown in perspective in its folded condition. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    With reference to the figures, which are shown by way of exemplification and not limitation, a system and method for storing and transporting annular coiled material such as wire, rope, hosepipe, electric cable, and similar elongate material coiled into a number of discreet coils is described. 
         [0018]    With reference to  FIGS. 6 and 7 , two embodiments of a post are shown, generally identified by the numerals  10  and  10 ′, and having features of the invention. The post is preferably made from a single sheet of lightweight cardboard material, although a structure made from more than one such sheet is within the scope of the invention. The term “cardboard” as used herein is synonymous with the term “paperboard” which is board manufactured from fiber and other material that is commonly used to make paper, and which is lightweight and foldable. 
         [0019]    In a preferred embodiment, the cardboard material is corrugated cardboard, which is known and comprises a relatively thin sheet of cardboard folded into a sinusoidal wave form that is sandwiched between two flat sheets of cardboard, one glued to the upper peaks and one to the lower troughs of the wave form. This configuration provides a relatively strong and lightweight composite sheet of corrugated cardboard. 
         [0020]    In making the first embodiment of the post  10 , a flat rectangular sheet  50  of cardboard such as is exemplified in  FIG. 4  is cut out or manufactured. The sheet is bounded by a top edge  52 , a bottom edge  54 , a left edge  56  and a right edge  58 . The size and thickness of the rectangular sheet will depend on the size and weight of the coiled material that is to be stacked. Two vertical fold lines  60 ,  62  may be pressed into the cardboard to facilitate the cardboard being folded so that the two vertical edges  56 ,  58  of the sheet are positioned adjacent each other (as seen in  FIG. 6 ) to produce a post with a triangular cross section which is, preferably, an equilateral triangle. At the bottom edge  54  of the sheet a single horizontal fold line  70  may be pressed into the cardboard, a few inches from the bottom edge of the sheet. Each of the fold lines  60 ,  62  are cut through the cardboard from the base edge  54  of the sheet to the horizontal fold line  70 , thus allowing tabs  82  to be folded outwardly from the sheet when the sheet is triangularly folded, as exemplified in  FIG. 6 , to effectively provide the post  10  with an outwardly extending lower flange  82  at a lower terminal end. Thus, when folded, a post with a triangular cross section is achieved having three side panels  72 ,  74 ,  76 . In two corners  80 ,  82  (corresponding with fold lines  60 ,  62 ) the cardboard material extends continuously around the corner, but at a third corner  84  the cardboard is discontinuous where vertical left edge  56  and right edge  58  meet and are adjacent. 
         [0021]    In the second preferred embodiment a post  10 ′ of the present invention is provided in which a sheet  50 ′ may be configured in similar form to the first embodiment post  10 , with all equivalent components being given the same numeral as in the first embodiment with a “prime” mark. However, the second embodiment includes a third fold line  64  extending vertically a few inches from vertical edge  58 ′ to provide a flap portion  78 . Thus, when folded into triangular configuration as seen in  FIG. 7 , the post  10 ′ includes a third corner  84 ′ in which cardboard extends continuously around the third corner from panel  76 ′ to flap portion  78 . In all other respects, the post  10 ′ of the second embodiment is similar to post  10  of the first embodiment. 
         [0022]    In use, the post of the invention (either embodiment  10  or  10 ′) may be conveniently set on the floor with the flange formed by the tabs  82  extending outwardly in contact with the floor as seen in  FIGS. 6 and 7 . A first discrete coil  100  of material may be placed with care over the post to rest upon the tabs  82  as exemplified in  FIG. 3 . Once in this position, the weight of the coil serves to press the tabs to the floor and thereby stabilize the post extending above the first coil against overturning. Thus, a further plurality of similar coils  102 ,  104 ,  106 ,  108 , etc. may be placed on top of the first coil. As shown, each coil may be bound together with its own tie or tape  110  so that the coiled material does not unravel. It will be appreciated that the added weight of the further coils serves to press the tabs to the floor with even greater force, to provide enhanced stability to the overall structure. The post is specially configured in size so that each of the three corners  80 ,  82 ,  84  of the triangular cross section of the post fits snugly within and in substantial contact with the inner circumferential surface  102  of each of the coils as exemplified in  FIG. 2 . With this configuration, wherein each corner of the post is in substantial contact with the inner circumferential surface of each of the coils, the coils have little leeway for lateral movement and so will not tend to slide and bump into the corners of the post, to damage the post, while being transported. As will be appreciated, impact loads caused by an object bumping a corner may be many times larger than a statically applied load under gravity by the same object. Thus, the snug fit configuration of the post inside the coils tends to reduce impact loading on the post and preserves the cardboard structure from undue damage during transport. 
         [0023]    In a further aspect of the invention, once the coils are stacked on the post and the whole assembly is ready for shipment, lightweight ties may be applied to hold the discrete coils together, and to hold the collection of coils on the post  10 ,  10 ′, as described below and exemplified in  FIGS. 1-3 . Although the ties may be twine with circular cross section, the ties are preferably a flat strap of rectangular cross section made of plastic or metal which distributes the load evenly at its points of contact, thereby reducing the tendency, when placed under tension, to cut into the cardboard post and the coiled material. Where the first embodiment  10  is used, two ties  120 ,  122  are positioned to extend through the inside core  12  of the post, each tie extending along a line in one of the corners  80 ,  82  of the post formed by the fold lines  60 ,  62  of the sheet  50 . It will be appreciated that, once these two ties are tensioned and “knotted” against release of tension, the shape of the post prevents the coils from sliding in relation to the post. Rather, the shape of the post allows the ties to exert a firm fixture between post and coils. A third tie  124  may be positioned to extend along the corner of the post where the edges  56 ,  58  of the folded sheet meet and are adjacent each other but provide no continuous cardboard around the corner  84 . It will be appreciated however that this third tie  124  cannot exert a substantial force between the coils and the post in the first embodiment  10  because the post lacks continuity at that point. However, the third tie provides a force for joining the discrete coils together into one elongate cylinder, and together with the other two ties provides a balancing force by providing three symmetrically applied forces holding the coils together. 
         [0024]    Where the second embodiment  10 ′ is used, the third tie  124  may be positioned inside the continuous corner  84 ′ and will also bind the post to the coils to provide additional stability and rigidity to the overall configuration. 
         [0025]    When the assembly of post and coils tied together by the ties as described above is subject to transport and the inevitable loading that comes with shipment and movement of such an object, the shape of the post is found to provide extremely advantageous structural properties. 
         [0026]    First, it is found that lateral loads that are applied to a coil  100  are transmitted into the post  10 ,  10 ′ through a corner  80 ,  82 ,  84  ( 80 ′,  82 ′,  84 ′) of the post. Thus, external lateral loading on the coil/post assembly transfers to the post as a point load on at least one of the three corners of the post. It is found that, although the post is made of cardboard that may otherwise be relatively flimsy when taken on its own as a planar sheet, the post&#39;s special configuration when folded is sufficiently reinforced at each of its three corners by two of the three planar sides  72 ,  74 ,  76  extending towards its corners  80 ,  82 ,  84 . Thus, it is found that the corners are the stiffest and most reinforced portions of the post for application of a lateral point load to the assembly of coils with the post. 
         [0027]    Second, it is found that the triangular sectional shape of the post is capable of withstanding a relatively large bending moment about the longitudinal axis of the post. A bending moment about the longitudinal axis may be developed when the post is supported at each terminal end, but is not supported between the ends, and the post with its load is held horizontally. Rather, the gravitational load exerted by the coils causes the middle of the post to sag, while the ends are supported. This causes a tension load to develop in the post in the portion below the longitudinal axis, the tension load acting parallel with the axis; it also causes a compression load to develop in the post in the portion above the longitudinal axis, the compression load acting parallel with the axis. A compression load acting parallel with the longitudinal axis will tend to cause the compression zone to “buckle” and deform away from extending linearly from one end of the post to the other. However, because the corners are well reinforced against shear forces by two sheets terminating at each corner, the corners are found to resist buckling to a large degree. Therefore, the novel configuration of the post of the present invention is found to withstand a surprisingly large bending moment without collapsing by buckling. 
         [0028]    Third, while the ties  120 ,  122 ,  124  in the corners  80 ,  82 ,  84  of the post prevent the coils from slipping off the top of the post during transport, the ties are also found to hold the corners of the post in a fixed relation to each other to prevent the triangular shape of the post from being forced out of shape in a buckling action. This has additional significance in situations where the post as a whole is subjected to bending along its longitudinal axis, as described above. In a situation like this there is a tendency for a corner to “buckle” and deform away from extending linearly from one end of the post to the other. However, it is found that the presence of the ties in each continuous corner add stability and tend to prevent such deformation from occurring, thereby strengthening the overall structural integrity of the post when loaded with coils. 
         [0029]    Once the assembly of coils mounted on the post have been conveyed to a retail store or other sales outlet point, the assembly may be stood on one end with the flanged tabs  82  positioned underneath for stability, as seen in  FIG. 3 . The ties  120 ,  122 ,  124  may be cut, so that consumers may freely remove the uppermost coil and take it to the cashier for purchase. As coils are sequentially removed from the top, the post  10 ,  10 ′ becomes increasingly exposed. When the last coil is taken, the post may be removed and flattened into its original sheet configuration which is easy to store in combination with other sheets that have become emptied of their stock. 
         [0030]    Accordingly, the sectional shape of the post provides it with a unique and useful configuration for a cardboard structure that is required to support a stack of heavy annular objects under load conditions that may be considerable. 
         [0031]    Thus, the present invention also addresses with novel and useful features a need that is found in the art. The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.