Partition structure for cartons

Abstract

A carton having a plurality of interconnected side walls and at least one partition member attached to the inside of the side walls to form a plurality of rectangular cells. Top and bottom closures are provided which not only reinforce the side walls but permit the side walls to be made of material with good column crush properties without wasting such material for top and bottom flaps.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is related to shipping cases and cartons. More specifically, this invention provides partition structures for corrugated cartons to not only form a plurality of rectangular cells within the cartons, but to structually enhance such carton.

2. Description of the Prior Art

Conventional cartons, especially those composed of fibreboard or corrugated cardboard, have a campaign life that generally depends upon the number of times the cartons are employed in shipping operations, and the quality and quantity of material that is being shipped within the cartons. The cartons are inherently manufactured to withstand some handling mishaps and droppings that occur in a normal shipping operation. But these conventional cartons are generally not built to withstand good warehouse stacking and the flexural stiffness component of these cartons are generally such that the walls usually bow, buckle or fail when warehouse stacking is attempted or after extended use. The portions of the walls within conventional cartons generally possess an extended length between corners and support points; therefore, the undesirable flexural stiffness component causes definable changes in the overall structure of the carton when warehouse stacking is attempted.

Therefore, what is needed and what has been invented is a novel carton that overcomes the foregoing deficiencies.

SUMMARY OF THE INVENTION

Therefore, an object of the invention is to provide a shipping carton having immobile partitions, possessing strength in the top-to-bottom direction, and capable of withstanding good warehouse stacking.

It is another object of this invention to provide a carton with a highly desirable flexural stiffness component, good column crush properties, economically feasible to manufacture, and less expensive for a given stacking strength.

It is yet another object of the invention to provide a carton manufactured with versatility for split carton shipping, and possessing walls which have equal strength to the partitions.

The foregoing objects are achieved according to the practice of this invention. Broadly, this invention comprises four interconnected sidewalls, a bottom panel connected to the sidewalls, and at least one partition member attached to the inside of the sidewalls to form a plurality of rectangular cells while reinforcing the sidewalls. A top closure member is also provided. This invention additionally conceives of an upwardly flanged rectangular bottom panel, a pair of essentially figure 8 shaped bottom members snugly engaged within the upward flanges of the bottom panel so as to form four rectangular cells of substantially equal volume, and a downwardly flanged rectangular top closure member wherein the downward flanges telescopically fit the top edges of the pair of body members.

These, together with various ancillary objects and features which will become apparent as the following description proceeds are obtained by this novel carton, preferred embodiments being shown in the accompanying drawings, by way of example only wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of two substantially L-shaped partition members utilized in the invention;

FIG. 2 is a perspective view of a carton with the partition members of FIG. 1 attached therein;

FIG. 3 is a horizontal sectional view taken in direction of the plane of line 3--3 in FIG. 2;

FIG. 4 is a partial enlarged sectional view showing the connection of one end of a partition member to a sidewall;

FIG. 5 is a perspective view of a carton disclosing another embodiment of top and bottom closure member;

FIG. 6 is a perspective view of a carton having partition members forming six rectangular cells within the walls of a carton;

FIG. 7 is a partial perspective view showing the use of one partition member in forming four rectangular cells within a carton;

FIG. 8 is a partial perspective view showing the use of two partition members in forming seven rectangular cells within a carton;

FIG. 9 is a partial perspective view showing the use of one partition member forming five rectangular cells within a carton; and

FIG. 10 is an exploded view disclosing two split cartons firmly engaged within a bottom member forming four rectangular cells within the carton.

DETAILED DESCRIPTION OF THE INVENTION

With continuing reference to the drawings wherein similar parts of the invention are identified by the same reference numeral, and in particular FIGS. 1-5, there is seen a carton 20 including interconnecting side walls 22, 24, 26 and 28. A bottom 30 is provided. Partition members 32 and 34 are substantially L-shaped and include folded end flanges 36, 38, 40 and 42 respectively. When flanges 36 and 38 are adhesively bonded or glued to the sidewalls 26 and 28 respectively, and when flanges 40 and 42 are attached to contiguous sidewalls 22 and 24, four rectangular cells of essentially equal volume are formed within interconnecting sidewalls 22, 24, 26 and 28. The flanges reinforce the sidewalls at approximately their midpoint. Preferably, the connection point of all flanges to their respective sidewalls are such that there is no more than approximately six inches separating any fixed partition from a corner of the four interconnecting sidewalls or from another fixed partition. The purpose of this is to allow the reduction of the flexural stiffness component in each sidewall without reducing the strength or the resulting carton construction.

In accordance with this aspect of the invention, it has been found that for cartons constructed of the usual single ply corrugated board, the optimum side wall length between partitions that are affixed to the sidewalls, i.e., the partitions are an integral part of the case structure, as per the invention, is between 2 and 6 inches, most preferably between 3 and 5 inches. This is illustrated in FIGS. 3 and 6 where the distance L between fixed members should be within the foregoing limits for maximum compression strength for the carton. The following Table I gives compression failure values for tubes of various dimensions having a square cross section and constructed of single ply corrugated cardboard. In each case, force was applied to the top of the tube until it failed. Failure consisted of buckling of the tube at the intersection of 45.degree. lines drawn from opposite corners of a side wall of the tube.

TABLE I ______________________________________ Pounds Per Inch of Average Pounds Tube Size Perimeter to Failure to Failure ______________________________________ 2" .times. 2" 30 242 4" .times. 4" 32 506 5" .times. 5" 32 636 6" .times. 6" 30 722 7" .times. 7" 26 725 ______________________________________

When partition members 32 and 34 are positioned within carton 20 and their flanges are attached to the inside of the side walls, at the connection points the thickness of the side walls is approximately doubled. This can be best seen in FIG. 4 which discloses flanges 42 of partition member 34 bonded to sidewall 22.

Carton 20 may additionally include a top having rectangular extension members 44, 46, 48 and 50 transversely hinged at the top edge of each sidewall 22, 24, 26 and 28 respectively, so that when extension members are folded towards the center of carton 20, the extension members overlap to enclose the insides of carton 20. The transverse edges of extension members 46 and 50 are in abutting position when folded over the top of extension members 44 and 48.

A variation of a preferred embodiment of the invention is disclosed in FIG. 5 and FIG. 10 where bottom panel 30 is upwardly flanged with flanges 31, and sidewalls 22, 24, 26 and 28 are snugly engaged therein. Top member 52 may include downward flanges 54 telescopically fitting the top edges of the side walls, and glued or bonded thereto.

This structure has the advantages due to the separate top and bottom closures. Resistance to edge roll is increased due to double thick material boged at the horizontal edges, and one inner wall is also double as shown in FIG. 10. Effective single sidewall height is reduced so flexural stiffness will tend to increase. Smooth top and bottom surfaces are presented for facilitating stacking and load sharing.

Still another variation of the concept of the invention is the embodiment disclosed in FIG. 6 which illustrates a substantially U-shaped partition member 56 having flanges 58 and 60 glued or bonded to sidewall 28. Also disclosed in FIG. 6 is partition member 62 which is essentially U-shaped having the top of each arm defining substantially an L-shaped form with folded flanges 64 and 66 glued or bonded to sidewalls 26 and 22 respectively, so that partition members 56 and 62 form six rectangular cells of essentially equal volume within sidewalls 22, 24, 26 and 28.

FIG. 8 illustrates partition members 80 and 82 having edges 84, 86 and 88, 90 respectively. Partition members 80 and 82 are essentially FIG. 8-shaped and each interconnect opposed sidewalls 24 and 28 to form seven rectangular cells within four interconnecting sidewalls 22, 24, 26 and 28 with four of the seven cells having essentially the same volume. End walls 81, 83 and 85, 87 are bonded to the sidewalls 24 and 28 by glue or other appropriate means.

Another modification of the two partition member embodiment of the invention is shown in FIG. 7 which make provisions for a single partition member. FIG. 7 discloses partition member 68, having folded end edges 70 and 72, as an essentially Figure 8-shaped member with the lowermost portion and the uppermost portion each defining a rectangular opening glued or bonded to two diagonally opposite corners of the four interconnecting side walls 22, 24, 26 and 28 so as to form four rectangular cells of essentially equal volume. As shown in FIG. 7 the single partition 68 is affixed by glue or other appropriate means to side walls 22, 24, 26 and 28 at all points of intersection 68a, b, c and d.

FIG. 9 further discloses essentially a U-shaped partition member 74 having each arm defining a rectangular aperture with folded flanges 76 and 78 and connecting between opposed sidewall 28 and 24 to form five rectangular cells within four sidewalls 22, 24, 26 and 28.

FIG. 10 illustrates an embodiment of the invention adapted to split carton shipping. Bottom panel 30, having upward flanges 31 is provided. Separate outer containers defined by sidewalls 92a, b, c, d and 94a, b, c, d respectively are joined by bottom panel 30 and contain generally Z-shaped partitions 96 and 98. Flaps 96a, b and 98a, b of partitions 96 and 98 are glued or attached by other appropriate means to sidewalls 92a, c and 94 b, d. Also provided is top closure 52, including downwardly extending flanges 54 telescopically fitting the top edges of body member 92 and 94.

In manufacturing this novel carton and all of its modifications, it is preferred that the sidewalls and partition members be composed of solid fibreboard or corrugated cardboard that does not crush easily. Good column crush property need not be wasted in top closure members or bottom panel members because these members do not have to withstand the column crushing property of good warehouse stacking.

While the present invention has been described herein with reference to particular embodiments thereof, a latitude of modifications, various changes and substitutions are intended in the foregoing disclosure, and it will be appreciated that in some instances some features of the invention will be employed without a corresponding use of other features without departing from the scope of the invention as set forth.

Claims

I claim:

1. A carton comprising a plurality of interconnected side walls, a bottom connected to said side walls, and at least two angulated partition members engaging each other and attached to the inside of said side walls to form a plurality of cells, each of said partition members being essentially shaped in a figure 8 and each being bonded to two of said four side walls opposed from each other to form at least seven rectangular cells within said interconnected side walls with at least four of said cells having essentially the same volume.

2. A carton according to claim 1 wherein each cell is defined by length and width dimensions between side walls and said length and width dimensions are a minimum of from about 2 inches to a maximum of about 6 inches.