FIELD OF THE INVENTION

The present invention relates generally to an angled wall cell divider set, particularly for packaging applications.

BACKGROUND OF THE INVENTION

Cell divider sets are commonly used to partition a larger package into individual compartments or cells for containing a plurality of articles in the package. The dividers provide the cell walls, and each cell is typically defined by four walls, though this is not essential.

Typically, the package is used for shipping the articles. It is therefore important that the package protect the articles against shocks and vibrations encountered during shipping. At the same time, it is important to minimize the cost of packaging material. The cell divider sets are often used merely to partition the package. While separating the articles protects the articles in that the articles are not subjected to collisions with one another inside the package, cell divider sets often do not provide any additional protection.

A number of cell divider concepts provide shaped or angled walls to conform to the objects being contained in the cells. This further immobilizes the article within the package so that the article is not subjected to collisions with the cell walls. An illustrative example is provided in U.S. Pat. No. 778,074 for partitioning an egg carton, and such cell dividers are often used in packaging fruits which are subject to bruising. A characteristic of such typical uses is that the article being contained in the cells is substantially symmetric with respect to rotations in the cell about a vertically oriented axis, so that all four walls of a cell are sloped or shaped to conform to the shape of the article.

Wachter, U.S. Pat. No. 2,232,192, discloses cell dividers for medicinal capsules that, apparently, lay in the cells so that their elongate axes are not vertically oriented. An asymmetry in the configuration of the walls of the cell is provided by which one pair of opposed walls are sloped while the other pair of opposed walls are vertical.

A cell divider set defining a plurality of cells typically has a plurality of walls running one direction and a corresponding plurality of walls running in another direction. To reduce manufacturing and assembly cost, the walls running in one direction are often formed (typically stamped) from one blank or sheet of material. Thus, these walls are all coupled together, such as shown in U.S. Pat. No. 1,118,702, U.S. Pat. No. 1,767,797, and U.S. Pat. No. 2,766,924.

However, also in the context of an egg carton, U.S. Pat. No. 1,176,939 shows coupling all of the walls running in one direction together to strengthen and reinforce the structure even though this would add substantially to the cost. In the '939 patent, walls running in one direction are formed of a single blank, while walls running in the orthogonal direction are joined together with reinforcement members.

U.S. Pat. No. 937,805 discloses a fruit package that includes sloped walls running in two orthogonal directions, where each wall is formed as a separate piece and the pieces are joined together with slots. Each of the walls is relatively rigid as a result of having a cross-section that defines a complete triangle. As is well known in structural design, a triangle is inherently a rigid structure. For example, the common truss makes use of this property of triangles.

In all of the prior art cell divider sets employing shaped or sloped walls discussed above, the cells partition the package and snugly contain the articles, but they do not provide additional cushioning or shock absorption other than that which is inherent in the materials used the walls.

Increasingly, robotic equipment is used to fill the cells, in a package having cell dividers, with the corresponding articles. The robotic â€œhandâ€ used for placing an article in a cell is typically not as dexterous as a human hand. More particularly, robotics used in high volume, low cost manufacturing typically provide a pre-programmed range of motions. It is currently not economical in this setting to provide robotics that evaluate and adjust for excessive variation in the location of the article with respect to the cell. If the â€œhandâ€ runs into interference caused by exceeding the system tolerance for dislocation between these two elements, the operation fails.

The cell must be large enough to receive both the article and the portion of the hand that grips the article that would extend into the cell. Further, the cell has to be large enough to permit the robotic equipment to release the article, and thus expand the span of the hand. Still further, the system tolerance must be accommodated. It has been a problem in the art that when provided with sufficient space for robotic loading, the cells are too large to conform sufficiently to the articles to provide the needed protection.

Accordingly, there is a need for an angled wall cell divider set that provides for enhanced cushioning and shock absorption, especially for use in conjunction with robotic loading, at minimum cost.

BRIEF SUMMARY

Described herein is a cell divider set for forming a plurality of cells. A preferred cell divider set according to the invention provides a plurality of planar first walls and a plurality of second walls. The second walls are adapted for interlocking with the first walls such that the first walls are oriented in a spaced apart, parallel relation in a first direction and the second walls are oriented in a spaced apart, parallel relation in a second direction for defining the cells. At least one second wall comprises two acutely angled sides that are otherwise distinct from (a) one another, and (b) the sides of any other one of the second walls, so as to define two respective free edges of the at least one second wall. Preferably, the at least one second wall is formed by folding, along a fold line thereof, a substantially flat sheet of material to provide the two acutely angled sides.

Objects, features and advantages of the invention will be more readily understood upon consideration of the following detailed description taken in conjunction with the accompanying drawings. It is to be understood that this summary is provided as a means of generally determining what follows in the drawings and detailed description and is not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a pictorial view of a typical prior art cell divider set.

FIG. 1B is a pictorial exploded view of a portion of the cell divider set of FIG. 1A.

FIG. 1C is a pictorial exploded view of a portion of the cell divider set of FIG. 1A, showing a first slot arrangement.

FIG. 1D is a pictorial exploded view of a portion of the cell divider set of FIG. 1A, showing a second slot arrangement.

FIG. 2 is a pictorial view of a cell divider set according to the present invention.

FIG. 3 is a plan view of a blank for forming an angled wall of the cell divider set of FIG. 2 according to the present invention.

FIG. 4 is a cross-sectional view of one cell of the cell divider set of FIG. 2 taken along a line 4-4 thereof, showing an article contained in a cell.

FIG. 5 is a plan view of a planar wall of the cell divider set of FIG. 2 according to the present invention.

FIG. 6 is a pictorial view of an angled wall interlockingly disposed with respect to a planar wall according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1A shows a typical prior art cell divider set 10, useful for providing context for the present invention and defining terms used herein. The divider set is provided for partitioning or dividing a package 20 (shown in phantom lines). The cells are adapted to receive corresponding articles, and the package is typically adapted and used for shipping the articles.

The divider set and the package are typically formed of paperboard or corrugated fiberboard (hereinafter â€œpaperboardâ€ ). While this is not essential, and either can be formed of alternative materials within the scope of the invention, it is especially desirable to provide low cost in paperboard packaging and it is in this context that the invention provides greatest advantage.

The divider set is formed of two sets of walls that are formed of flat sheets, typically by die-cutting and die-scoring the sheets. With reference to the coordinate system 12, the walls 14 run in the â€œxâ€ dimension and the walls 16 run in the â€œyâ€ dimension. The â€œzâ€ dimension defines an elevation; the point â€œz₁â€ defines a lower elevation and the point â€œz₂â€ defines an upper elevation, it being understood that the terms â€œupperâ€ and â€œlowerâ€ are relative and that the term â€œelevationâ€ does not imply any particular direction or orientation in space.

The two sets of walls define a plurality of cells 15. The two sets of walls define four side faces (18) for interior cells 15a, three side faces for edge cells 15b, and two side faces for corner cells 15c. The package 20 receives the divider set and provides the additional sides for the edge and corner cells. While the two sets of walls are typically orthogonal as indicated and therefore define generally an orthorhombic cell, this is not essential.

FIG. 1B shows the divider set 10 exploded to illustrate how the walls 14 interlock with the walls 16 by the use of corresponding slots 22. More particularly, referring to FIG. 1C, slots 22a of the walls 14 run from edges of lower elevation 14L to intermediate points of elevation â€œz14_intâ€ on the walls 14, and slots 22b of the walls 16 run from edges of upper elevation 16U to intermediate points of elevation â€œz16_intâ€ on the walls 16. Alternatively, according to the present invention, the slots in one or both of the walls may alternate between running from an edge of lower elevation and an edge of higher elevation, such as the wall 14 shown in FIG. 1D. Alternation may be of any spatial frequency or may be irregular to provide any desired pattern.

The slots are aligned as indicated by the dashed lines in FIGS. 1C and 1D, and the walls are brought together with the result shown in FIG. 1A and at 28 in FIG. 1B wherein the walls are interlocked together to assemble the divider set 10. Typically, as assembled, the edges of upper and lower elevation for all of the walls are at the same elevation as shown in FIG. 1A, but this is not essential.

Turning now to FIG. 2, a cell divider set 30 according to the present invention is shown. With reference to the same coordinate system 12 referred to above, walls 34 run in the â€œxâ€ dimension and walls 36 run in the â€œyâ€ dimension, defining a plurality of cells 32. All of the comments made above regarding the divider set 10 apply to the divider set 30 except as set forth below.

The walls 34 are similar to the walls 14 of the cell divider set 10 in that they are planar. However, at least every other wall 36 possesses a three-dimensional configuration, a preferred embodiment of which is shown. As can be seen from FIG. 2, the walls 36 are triangular in shape; however, due to the manner of their construction, they do not possess the rigidity of a fully triangular cross-section such as shown in U.S. Pat. No. 937,805, for example. This provides a number of advantages at exceptionally low cost.

Turning to FIG. 3, a blank 38 for forming one of the walls 36 is shown. The blank is planar, typically die-cut from a sheet of paperboard, but is folded along a fold line 40, which is typically though not necessarily scored for this purpose, to achieve the three-dimensional configuration shown in FIG. 2. When folded, the blank provides two acutely angled sides 36a, 36b, having respective outer side faces 36as, 36bs (FIG. 2). The sides 36a, 36b are joined together at the fold line 40, but are otherwise distinct from each other and distinct from any of the sides of the other walls 36 so that free distal edges FE are provided. Because the distal edges are free, the sides of the walls 36 can pivot substantially and act as damped springs via flex of the hinge joint at the fold line 40 in response to any compressive forces applied in the â€œxâ€ dimension, and thereby absorb as well as dissipate energy resulting from shock.

FIG. 4 shows an article 41 contained in one (32a) of the cells 32 along with reference to an â€œx-zâ€ portion of the coordinate system 12 indicated as 12a. The wall 36₁provides two sides 36a₁and 36b₁. The similar wall 36_{2 provides}two sides 36a₂and 36b₂that are angled with respect to each other by an acute angle Î¸. When the wall 36₂is relaxed, there are equal angles Î¸_2aand Î¸_2bon either side of a vertical line L along the â€œzâ€ axis. Similarly, when the wall 36₁is relaxed, there are similar equal angles Î¸_1aand Î¸_1b.

However, in response to, e.g., movement of the package 20 (shown in FIG. 1 but not in FIG. 4) in which the divider set is disposed, the article 32 may apply a compressive force â€œCF,â€ e.g., in the positive â€œxâ€ direction to the outer side face 36as₁, of the side (36a₁) of the wall 36₁, as a result of sliding in the same direction. The angle Î¸_1awill become smaller as the side 36a₁, pivots about the hinge joint formed at the fold line 40, the hinge joint flexing and absorbing energy.

As seen in FIG. 3, slots 42 run from the free distal edges FE to intermediate points of elevation â€œz36_int,â€ where the elevational nature of the points is seen when the blank is assembled along with the walls 36 as shown in FIG. 2. The slots 42 receive portions of the walls 34 for interlocking with the walls 34 while allowing pivoting of the sides 36a and 36b.

FIG. 5 shows one (34a) of the walls 34; particularly FIG. 5 shows two illustrative alternative slot configurations 43_alt1and 43_alt2for the walls 34 for interlocking with two similar walls 36₁and 36₂. The point â€œz36_intâ€ indicates the top of slots 42 in the walls 36₁, 36₂, the slots otherwise not being discernible in the Figure.

Each slot 43_alt1, and 43_alt2(or slots 43) comprises an uprising, central projection CP flanked on each side by two slot portions SP, the slot portions corresponding to material that is removed from a sheet of material from which the wall 34a is formed. The slots 43 extend from an edge of upper elevation â€œEâ€ down to an intermediate elevation â€œz34a_int.â€ In all cases, the slot portions extend downwardly to an elevation that is lower than the intermediate elevation â€œz36_intâ€ while the central projection extends upwardly to a projection elevation z_proj1, z_proj2that is higher than the intermediate elevation â€œz36_int.â€ In cooperation, the slots 42 extend upwardly from the free ends FE of the walls 36₁, 36₂to an elevation â€œz36_intâ€ that is lower than the projection elevations z_proj1, z_proj2.

FIG. 6 shows a wall 34 interlocked with a wall 36 along with the aforedescribed relationship between the three elevations â€œz_proj,â€ â€œz34_int,â€ and â€œz36_intâ€ for the slot 43alt2. The relationship provides essentially for hooking the upper portion of the wall 36 extending above the elevation of the slot 42 therein within the slot portion SP. Applying a force F as indicated will bend the side 36a below the elevation â€œz34_intâ€ (at the portion of the side 36a that is proximate the plane of the wall 34aâ€”the side 36a will bend at higher elevations farther from this plane), but bending of the side above this point will be prevented by interference with the central portion CP. Similar considerations pertain to the slot 43_alt1, and any other slot configuration providing for the aforedescribed relationship may be used without departing from the principles of the invention.

It should be noted that the elevation of the fold lines 40 of the walls 36 may be at the same elevation as that of the upper edge E of the walls 34 (such as shown in FIG. 4), may be at a lower elevation (such as shown in FIG. 5), or may be at a higher elevation (not shown), depending on the configuration of the slots 43.

In addition to dividing or partitioning a package into cells, and in addition to conforming to the size of the article to minimize movement of the article within the cell, the walls 36 as described above provide the outstanding advantage of being flexible. As mentioned above, the sides of the walls 36 can pivot substantially and act as damped springs via flex of the hinge joint at the fold line. In addition, the sides of the walls are not further constrained by being joined to one another, or by being joined to the sides of other walls 36. As a result of the flexibility of the walls 36, the article can be somewhat larger than the space provided between opposite sides of a cell and the sides will compress to hold the article more firmly. In addition, movement of the sides will absorb and dissipate energy to reduce shock that would otherwise be applied to the article. The walls 36 are also highly economical to manufacture.

The walls 36 provide an additional advantage in the context of robotic insertion of articles into the cell divider set. Assuming that the articles are inserted from a higher elevation down into the cells, the walls 36 provide for a diminishing width of the cells as elevation is decreased. A robotic end effector or â€œhandâ€ (not shown) for gripping an article, placing the article into a cell, and releasing its grip on the article, is provided more space at higher elevations within the cell than at lower elevations. Thus, there is space in the cell, particularly for the end effector to release its grip on the article, at upper elevations within the cell even while the article is nevertheless firmly held by the walls 36 at lower elevations in the cell.

As the walls 34 are planar they are even more economical to manufacture than the walls 36, in that they do not require a step of folding. Moreover, it is typically only necessary that the robotic end effector be able to grip and release its grip along one dimension only. Providing the walls 36 to run in the â€œyâ€ dimension and the walls 34 to run along the â€œxâ€ dimension takes advantage of this requirement and provides for greater economy than would be required if walls 36 were provided in two directions. To realize further economy, planar walls may be alternated with the walls 36 such that each cell has only one flexible side as provided by a wall 36. In that case, the robotic end effector may be programmed to release its grip by expanding in only one direction to realize at least some of the advantages of the present invention.

It is to be recognized that, while a particular angled wall cell divider set has been shown and described as preferred, other configurations and methods could be utilized, in addition to those already mentioned, without departing from the principles of the invention. For example, curved walls can be used without departing from the principles of the present invention.

The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation, and are not intended to exclude equivalents of the features shown and described or portions of them. The scope of the invention is defined and limited only by the claims that follow.