Abstract:
A method of making a multiple ply slotted partition for use in a slotted partition assembly is provided. The slots of the partitions are engaged with each other at a plurality of intersections. The partitions are made by folding over a partition blank and securing a foam portion of the folded partition blank to itself. The foam may be heated before being cooled to secure opposed plies of the multiple ply partition together. The opposed plies of the partition are fused or parent welded together.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 11/036,809, filed Jan. 14, 2005 entitled “Partition Assembly Made With Multiple Ply Partitions”, now U.S. Pat. No. 7,344,043, which is fully incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a partition assembly for dividing the space inside a container or box; more particularly to a partition assembly made of slotted, multiple ply partitions. 
     DESCRIPTION OF THE PRIOR ART 
     In the storage, shipment or display of parts or merchandise, it is a common practice to divide the interior of a box or container into a plurality of individual cells. The interior of a box or container is typically separated by a series of dividers, one set of parallel dividers being orthogonal to a second set of dividers. The dividers separate the interior of the container into a plurality of individual holding cells each of which is intended to hold a separate item for display and/or shipment. The division of the interior of the box or container helps prevent the items therein from contacting one another and breaking during shipping. The division or partitioning of the container also aids in the loading and unloading of the items therein, as well as inventorying the contents of each box or container. 
     The dividers typically are slotted and arranged in an orthogonal relationship to divide the interior of the box or container into a desired number of holding cells. The dividers are slotted in a manner that enables the dividers to engage with one another at the location of the slots so that the dividers form an orthogonal grid or matrix. Typically the dividers are made of the same material as the material of the box or container, plastic or paperboard. However, the dividers may be constructed of any suitable material with sufficient rigidity to prevent the contents of the container from contacting one another and being damaged. 
     One disadvantage with known partition assemblies is that the upper edges of the partitions may have exposed sharp edges. For example, corrugated plastic partitions may have sharp upper edges created by cutting a sheet of corrugated plastic to the desired partition size. Such an exposed upper edge of the partition may damage products or parts being loaded into or unloaded from the cells of the container in which is located the partition matrix or assembly. Partition assemblies incorporating partitions having exposed sharp upper edges may require additional clearance between the parts being either loaded or unloaded and the upper edges of the partitions. 
     Another disadvantage of such partition assemblies is that the person loading or unloading parts or products into or from the cells of the container may cut or scrape their knuckles or hands on the exposed upper edges of the partitions when loading or unloading parts or products. 
     Additionally, the stiffness of the partitions of the assembly is dictated by the material from which the partitions are made. The stiffness of the partitions may not be altered without changing the material from which the partition is made. 
     U.S. Pat. No. 2,647,679 discloses a partition assembly which separates the interior of a box or container into a plurality of cells. The partitions of the assembly disclosed in this patent are formed by folding a blank of material along a fold line so as to create a rounded smooth upper edge. The material is disclosed as being paper board or similar material. 
     Another partition assembly for dividing the interior of a container is disclosed in U.S. Pat. No. 4,375,263. The partitions of this assembly are similarly rounded along their upper edges and are made of transparent vinyl sheets. 
     In each of these prior art partition assemblies, the opposed plies of the dividers or partitions formed by folding a blank of material are not secured to each other. Consequently, the opposed sides or plies of the partitions are not secured to each other and may be easily separate, thereby expanding into the cells of the container defined by the partition assembly. Consequently, the partitions may contact the products or parts stored in the cells and damage them. Additionally, the partition plies may easily tear or otherwise be damaged. Upon assembly or disassembly of the partition matrix, one or more portions of the partitions may tear and hence cause disassembly of at least a portion of the partition matrix. 
     It therefore has been one objective of the present invention to provide a double-ply partition for use in a partition assembly in which the plies are secured together. 
     It has been a further objective of the invention to provide a method of manufacturing a double-ply partition for use in a partition assembly which is secure and may not be easily disassembled. 
     It has been another objective of the present invention to provide a double-ply partition for use in a partition assembly in which the partition has the desired degree of stiffness. 
     SUMMARY OF THE INVENTION 
     The partition assembly of the present invention which accomplishes these objectives comprises at least one first slotted partition intersecting with at least one second slotted partition at an intersection. The intersecting first and second slotted partitions form a plurality of holding cells into which different parts are stored for shipment or display. 
     Each first slotted partition has at least one slot extending inwardly from an edge of the first slotted partition. Likewise each second slotted partition has at least one slot extending inwardly from an edge of the second slotted partition. Preferably the slots are evenly spaced in order to make the holding cells which are defined by the intersecting partitions of identical dimensions. However, the slots may be located at any desired locations. In one embodiment, each of the slots of a first slotted partition extends inwardly from an edge of the first slotted partition to approximately the midpoint of the first slotted partition. Each of the slots of a second slotted partition extends inwardly from an edge of the second slotted partition to approximately the midpoint of the second slotted partition. 
     In one embodiment of the present invention, the partition is formed of a multilayered material folded in half and secured to itself. The fold creates a rounded upper edge at the fold line which is smooth and has a continuous surface with the outer side walls or skins of the partition. The partition blank comprises an inner layer of foam, preferably polyolefin foam, and an outer layer, skin or facegood. In one embodiment, the inner foam layer is bonded directly or laminated to the outer layer. The outer layer may be made of woven polyester, non-woven polypropylene, foamed or solid polyolefin or other material such as latex or non-polyolefin plastic. The outer layer may be selected as appropriate to protect or prevent surface damage to the products being stored and/or shipped in the cells of the container. 
     In an alternative embodiment, a desired stiffness or rigidity may be created in the partition by inserting into the partition blank from which the partition is made a thin plastic skin or middle layer between the inner foam layer and the outer layer or facegood. By altering the thickness and/or mechanical properties of this middle layer, or by omitting it altogether, the desired level or degree of stiffness of the partition may be achieved during the manufacturing process. 
     In an alternative embodiment, the partition blank may be made solely of one foam layer without any outer layer or facegood. 
     The method of manufacturing the multiple ply partition comprises multiple steps. Although the method is described with respect to one preferred embodiment, the method may be used with any of the embodiments contemplated by this invention. 
     In one instance, a multiple layered partition strip or blank having an outer skin secured to a foam interior is first provided. This partition blank may be made using any desired known method such as co-extrusion, lamination, etc. 
     The partition blank is folded so as to create two opposed plies and a smooth edge connecting the plies. The foam interior layer of at least one of the plies is heated with a heat source. The heat source is placed in such proximity to the contacting portions of the partition plies so that heat from the heat source causes the foam portion of at least one of the partition plies to become at least partially molten. The heat source is then distanced from the partition plies and the foam portions of the partition plies allowed to cool under pressure, thereby creating a securement of the foam layers or portions of the partition plies to create a unitary partition having a foam interior portion surrounded by an outer skin. The heat source may be hot air or any other suitable heat source. 
     In this manner, the plies of the partition are parent welded or fused together along their interior or inner surfaces. For purposes of this document, the term “parent weld” or “parent weldment” refers to a weldment of two contacting partition plies welded, fused or secured together without the use of any additional material other than the material of the partition plies themselves. The present invention is not intended to be limited strictly to foam, partition plies made of corrugated plastic may be parent welded together in accordance with the present invention in a manner disclosed and taught in assignee&#39;s U.S. Pat. No. 5,788,146, which is fully incorporated herein. 
     One advantage of using a partition blank having a foam interior made of a polyolefin foam is that the two plies of the partition blank may be secured or fused together using only heat, thereby eliminating the need for additional material such as adhesive, staples or other fasteners. The omission of the additional material may reduce the labor and material cost of making the slotted partition. The securement of the two plies together using only heat may not be possible or economically desirable with other materials such as paperboard, commonly used to make partitions. 
     Such a process of welding opposed plies of a partition together without the use of any additional material other than the material of the partition plies to form a multiple ply partition having the desired stiffness is quick, economical and allows many multiple ply partitions to be mass produced with low material and labor costs, Once the portion of at least one ply is separated from the heat source and allowed to cool, the plies are parent welded together in a permanent relationship. 
     An alternative method of joining the foam interior layers of the plies of the partition is to adhesively secure them together. Other means of securing the foam interior layers of the folded partition plies may used if desired. 
     This method of making a two-ply partition by securing opposed plies of the partition together is quick, easy and inexpensive. The opposed plies of the partition are permanently secured to each other, making the partition non-disassembling and enhanced by being double layered or double ply without using any additional material or tools. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the partition assembly of the present invention located inside a container; 
         FIG. 2  is a perspective view of the construction of the partition assembly of  FIG. 1  illustrating a plurality of first slotted partitions and a plurality of second slotted partitions; 
         FIG. 3  is a cross-sectional view taken along the line  3 - 3  of  FIG. 2 ; 
         FIG. 3A  is a cross-sectional view of an alternative embodiment of a partition used in accordance with the present invention having a middle layer; and 
         FIG. 4A  is a diagrammatic side elevational view illustrating a method of manufacturing partition blanks according to one embodiment of the present invention; 
         FIG. 4B  is a diagrammatic side elevational view illustrating a method of manufacturing a roll of material used to make partition blanks according to another embodiment of the present invention; 
         FIG. 4C  is a diagrammatic side elevational view further illustrating the method of manufacturing partition blanks according to the method of  FIG. 4B ; 
         FIG. 5A  is a perspective view of a partition blank; 
         FIG. 5B  is a perspective view illustrating the partition blank of  FIG. 5A  being folded; 
         FIG. 5C  is a perspective view illustrating the interior foam layers of opposed plies of the partition blank of  FIG. 5A  being heated; 
       FIG.  5 C 1  is a perspective view illustrating the interior foam layers of opposed plies of the partition blank of  FIG. 5A  being joined without heat; 
         FIG. 5D  is a perspective view illustrating the heated partition blank of  FIG. 5C  cooling under pressure according to one embodiment of the present invention; 
         FIG. 5E  is a perspective view illustrating a method of cutting a two-ply partition to size; and 
         FIG. 5F  is a perspective view illustrating a finished slotted partition according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings and particularly to  FIG. 1 , there is illustrated a partition assembly  10  for dividing the space inside a container  5 . Although one type or configuration of container  5  is illustrated in  FIG. 1 , the partition assembly  10  of the present invention may be used in any type of container or box. As illustrated in  FIG. 2 , the partition assembly  10  comprises a plurality of parallel first slotted partitions  12  intersecting with a plurality of parallel second slotted partitions  14 . 
     As shown in  FIG. 2 , each first slotted partition  12  has a rounded upper or top edge  16 , a planar bottom edge  18  and two opposed side edges  20 . Likewise each second slotted partition  14  has a rounded upper or top edge  22 , a planar bottom edge  24  and two opposed side edges  26 . 
     Each first slotted partition  12  has at least one slot  28  which extends downwardly from the top edge  16  of the first slotted partition  12  to approximately the midpoint of the first slotted partition  12 . The slots  28  may be evenly spaced apart in order that the individual holding cells  7  of the partition assembly may be evenly sized. See  FIG. 1 . Alternatively, the slots  28  of the first slotted partitions  12  may be unevenly spaced in order to form holding cells of the partition assembly of differing sizes to accept different sized parts. The slots  28  are shown as being vertical but may be horizontal if the partition assembly  10  is placed on edge. 
     As shown in  FIG. 2 , each second slotted partition  14  has at least one slot  30  extending upwardly from the bottom edge  24  of the second slotted partition  14  to approximately the midpoint of the second slotted partition  14 . The slots  30  of the second slotted partitions  14  may also be evenly spaced in order so that the holding cells  7  of the partition assembly  10  may be evenly sized. Again see  FIG. 1 . Alternatively, the slots  30  may be unevenly spaced in order to form holding cells of the partition assembly of differing sizes adapted to accept different sized parts. The slots  30  are shown as being vertical but may be horizontal if the partition assembly  10  is placed on edge. 
     In one embodiment of the present invention each of the first and second slotted partitions  12 ,  14  is made of a multilayered material. Each of the partitions  12 ,  14  is a two-ply partition formed by the method shown in  FIGS. 5A-5F  and described below.  FIG. 3  illustrates one of the partitions  12  in detail according to one embodiment of the present invention. As best illustrated in  FIG. 3 , slotted partition  12  has two opposed plies  32  and  34  which are parallel to one another and joined together. The partition  12  has an outer layer or skin  36  assuming a generally inverted U-shaped configuration when the partition  12  is folded and the opposed plies  32  and  34  secured together. A wide variety of materials may be used for the outer layer or skin  36  including, but not limited to, woven polyesters, non-woven polypropylenes, foamed and solid polyolefins, latex, non-polyolefin plastics. 
     In the embodiment shown in  FIG. 3 , inside the outer layer or skin  36  is a foam interior  38  comprising two layers  40 ,  42  joined together along an interior surface  44 . A wide variety of materials may be used for the foam interior  38  of the partition  12 . In one preferred embodiment, the foam interior  38  is a polyolefin foam. However, other materials other than foam which may be welded or joined together may be used in accordance with the present invention. If desired, the outer skin  36  may be omitted, in which case, the entire partition  12  would be made of foam. 
       FIG. 3A  illustrates an alternative embodiment of the present invention. In this embodiment, partition  12   a  has an additional layer incorporated therein when compared to the partition  12  shown in  FIG. 3 . In this alternative embodiment, the partition  12   a  has an outer layer or skin  36   a , a foam interior  38   a  comprising two layers  40   a ,  42   a  joined together along surface  44   a . In addition, a middle stiffening layer  46  is secured between the outer layer or skin  36   a  and the foam interior  38   a . Like the outer layer  36   a  of the partition  12   a , the middle stiffening layer  46  assumes a generally inverted U-shaped configuration when the partition  12   a  is folded and the opposed plies  32   a  and  34   a  secured together as shown in  FIG. 3A . A wide variety of materials may be used for the middle stiffening layer or skin  46  including, but not limited to, various plastics. If desired, additional middle stiffening layers of any suitable material (not shown) may be added to the partition blank. The partition  12   a  has a smooth upper edge  75   a  like the partition  12  shown in  FIG. 3  created by the folding of a partition blank and securing the opposed plies  32   a ,  34   a  together in the manner described below. 
     Referring to  FIG. 4A , to practice the method of this invention and form a multilayered partition blank  66  for subsequent use in forming a slotted two-ply partition like partition  12  shown in  FIG. 3  for use in a partition assembly, a roll  48  of outer skin material is provided. As illustrated in  FIG. 4A , a web of outer skin material  50  is unwound from the roll  48  and passed between two heated conveyors  52 . Other heat sources may used if desired. Another roll  54 , this one containing a web  56  of foam material is provided. The continuous web  56  of foam is unrolled from the roll  54  and passed into a nip  58  between rollers  60 . The webs  50 ,  56  are joined together to create a multilayered web  62 . As shown in  FIG. 4A , the multilayered web  62  is passed between cooling conveyors  63  and then cut with cutting device  64  to create a partition blank  66 . Any suitable means for cooling the multilayered web  62  other than conveyors may be used if desired. The cut multilayered partition blanks  66  are then stacked on top of one another to create a stack  68 . 
       FIGS. 4B and 4C  illustrate another method of forming a cut multilayered partition blank  66   a . In this method, a roll  48   a  of outer skin material is provided. As illustrated in  FIG. 4B , a web of outer skin material  50   a  is unwound from the roll  48   a  and passed between two heated conveyors  52   a . Again, other heat sources other than conveyors may used if desired. Another roll  54   a , this one containing a web  56   a  of foam material is provided. The continuous web  56   a  of foam is unrolled from the roll  54   a  and passed into a nip  58   a  between rollers  60   a . The webs  50   a ,  56   a  are joined together to create a multilayered web  62   a . As shown in  FIG. 4B , the multilayered web  62   a  is then passed between cooling conveyors  63   a  before being rolled up into a roll  70 . As illustrated in  FIG. 4C , the multilayered web  62   a  is unrolled from roll  70  and cut with cutting device  64   a  at one or more desired locations to create a partition blank  66   a . The partition blanks  66   a  are then stacked to create a stack  68   a.    
     Although  FIGS. 4A-4C  illustrate several method of manufacturing a multilayered partition blank, any other suitable known method of making a multilayered partition blank may be used such as co-extrusion, heat bonding or laminating several layers together. 
     Once a multilayered partition blank  66 ,  66   a  has been created, the multilayered partition blank is then formed into a two-ply slotted partition  12  using the method illustrated in  FIGS. 5A-5F . For purposes of simplicity,  FIGS. 5A-5F  illustrate a method of creating a two-ply partition  12 . However, the same method may be used to create any partition used in accordance with the present invention.  FIG. 5A  illustrates a multilayered partition blank  66  in a planar flat orientation.  FIG. 5B  illustrates the multilayered partition blank  66  of  FIG. 5A  being folded along a fold line  74  so as to create two opposed plies  32 ,  34  and a rounded smooth edge  75  joining the plies as seen in  FIG. 3 . This smooth edge  75  becomes the upper edge of the partition  12 . 
       FIG. 5C  illustrates the interior foam layers  40 ,  42  of the opposed plies  32 ,  34 , respectively being heated with a heat source  76 . In the illustrated embodiment, the heat source  76  blows hot air in the direction of arrows  78  to heat at least one of the interior foam layers  40 ,  42  of the folded multilayered partition blank  66 . Of course, other types of heaters may be used in accordance with the present invention to heat at least one of the interior foam layers  40 ,  42  of the folded multilayered partition blank  66  using any number of known methods. 
       FIG. 5D  illustrates the interior surfaces  80  of the foam layers  40 ,  42  of the opposed plies  32 ,  34 , respectively, contacting each other and being under pressure from a pressure source  82  such as a press like the one illustrated in  FIG. 5D . In the illustrated press  82  opposed plates  84  contact the outer skin  36  of the folded multilayered partition blank  66 . Rods  86  extending outwardly from the plates  84  and joined thereto cause the plates to move to and away from each other in a known manner. As shown in  FIG. 5D , the plates  84  push the opposed plies  32 ,  34  of the folded multilayered partition blank  66  together until the inner surfaces  80  thereof contact each other. Pressure is then applied by the press  82  as the opposed plies  32 ,  34  of the folded multilayered partition blank  66  are cooled. The result is that the foam interior layers  40 ,  42  of the opposed plies  32 ,  34  of the multilayered partition blank  66  are fused together to create partition  12 . Although one type of press is illustrated any other type of device may be used to place the two opposed plies of the blank under pressure during the cooling process. Any method of cooling the opposed plies  32 ,  34  of the folded multilayered partition blank  66  may be used in accordance with the present invention to fuse the interior foam layers  40 ,  42  together including allowing the heated foam interior layer or layers to cool at room temperature. 
     As shown in FIG.  5 C 1 , the heater may be omitted from the process of manufacturing a slotted partition  12  shown in  FIG. 5F . In such a situation, adhesive  88  may be applied to the inner surfaces  80  of the opposed plies  32 ,  34  of the folded multilayered partition blank  66  either before or after the multilayered partition blank  66  is partially folded as shown in  FIG. 5B . Other known methods of securing the opposed plies  32 ,  34  of the folded multilayered partition blank  66  may be used if desired. 
       FIG. 5E  illustrates an unslotted two-ply partition  90  resulting from the securing of the opposed plies  32 ,  34  of the folded multilayered partition blank  66  together in any manner including those described above. One or move knives  92  may be used to cut the unslotted two-ply partition  90  to the desired size. 
     As shown in  FIG. 5F , slots  94  are then cut out of the unslotted two-ply partition  90  at the desired locations. The end result is a two-ply slotted partition  12  for use in a partition assembly such as the one  10  shown in  FIGS. 1 and 2 . 
     While I have described only a few embodiments of my invention, I do not intend to be limited except by the scope of the following claims.