Package Corner Post

Abstract

In a container for a bulky and heavy article generally cubic in shape, a vertical corner post for cushioning and protecting a vertical edge of the article. The corner post has a cross-section in the shape of the numeral 4 and is positioned such that a recess engages an adjacent outer edge of the article and a vertex of the post extends into an adjacent inner corner of the container. An hypotenuse panel of the post has a score line along its length which permits the hypotenuse panel to fold outwardly at the score line upon application of an extreme or repeated lateral compressive force to cushion the article against the force.

Description

The present invention relates to a cushioned container and, more particularly, the invention relates to a corner post which cushions and protects the corners and edge of a bulky and heavy article.

It is customary to package bulky, heavy articles, such as refrigerators, television sets, stoves, air conditioners, washing machines and dryers, within relatively lightweight but strong crates and containers, made of reinforced fiberboard, corrugated paperboard or light wooden slats. The article is usually cushioned within the lightweight container against damage from sharp blows occuring during transportation, storage or handling of the package. Conventionally, to provide lightweight cushioning protection, either a soft, flexible, relatively thick padding strip folded over to cover the sides and top corners of the article or a rigid protector made of a plurality of thicknesses of corrugated paperboard is utilized to maintain the article in spaced relation to the interior walls of the container.

However, many protectors which have been used do not permit the vertical stacking of loaded containers, as such stacking would result in damage to underlying containers and contents, particularly with heavy, bulky goods. When containers are stacked three to six levels high, the weight on the underlying containers is often sufficient to bend and break the corners and to buckle the walls which bear the major stacking load. This bending and breaking is made worse by the employment of a fork lift or other mechanical unit for handling the container with the result that the contents of the container are often damaged. In highly finished, heavy wooden furniture pieces or heavy consumer appliances, even minor scratches are a source of customer and dealer dissatisfaction with the manufacturer of the goods.

To overcome this problem, a vertical corner post protector having a cross-section in the shape of the numeral 4 was developed, as shown in U.S. Pat. No. 3,072,313. That corner post is designed to serve the dual function of providing ample vertical stacking strength for the container to prevent damage to the contents and cushioning the contents against lateral external blows or shocks. Such corner posts are preferably fabricated of corrugated paperboard, which is readily commercially available and which can be easily and inexpensively manufactured into the container-length corner posts.

The corner post shown in U.S. Pat. No. 3,072,313 has been found effective and commercially successful in resisting vertical compressive forces upon stacking of a number of containers. However, that corner post may gradually give way to extreme or repeated lateral forces applied to the container and to shifting movement of the article within the container. The lateral applied or shifting forces may crush the hypotenuse portion of the corner post and not leave any cushioning protection for the edge and corners of the article.

This difficulty is particularly aggravated when a squeeze-type handling unit is employed to lift the package rather than a fork-or blade-type lifting unit. If a squeeze-type unit is utilized, the corner post must be able to resist the extreme lateral squeezing force applied to the container, but must not be too rigid or the corner post itself may cause damage to the article being protected. The use of such squeeze-lift methods has been rapidly growing because of savings in space otherwise needed to accommodate the mechanical lifting fork or blade. Moreover, when using a squeeze-lift method, a regular slotted style container, as opposed to an interlocking flange cap and tube, may be employed. A slotted style container usually requires less corrugated material and is less expensive to fabricate.

Accordingly, an object of the present invention is to provide an improved lightweight corner post for cushioning and protecting the corners and edges of a bulky, heavy article.

Another object of the invention is to provide an improved corner post which protects an article in a container against both vertical and lateral compressive forces tending to buckle the walls of the container and thereby damage the contained article.

A further object of the invention is to provide an improved corner post for cushioning and protecting a packaged, bulky article against extreme or repeated lateral compressive forces as might be produced by a squeeze-type lifting unit.

Yet another object of the invention is to provide an improved corner post for use in a container for a heavy, bulky article which can be readily and inexpensively formed at the packaging location.

These and other objects of the invention will become apparent upon consideration of the following detailed description and accompanying drawings, in which:

FIG. 1 is a perspective view of a heavy, bulky article in a container and protected by corner posts;

FIG. 2 is an enlarged perspective view of a section of a corner post showing various of the details thereof;

FIG. 3 is a fragmentary view of a blank used to form the outer part of the corner post shown in FIG. 2;

FIG. 4 is an enlarged, fragmentary cross-sectional view taken along the line 4--4 in FIG. 1;

FIG. 5 is a view similar to FIG. 4 but illustrating the corner post after lateral compressive force has been applied;

FIGS. 6, 7 and 8 are views similar to FIG. 4 illustrating alternative embodiments of the corner post; and

FIGS. 6A, 7A and 8A are views similar to FIG. 5 showing, respectively, the corner posts illustrated in FIGS. 6-8.

Very generally, and with reference to FIG. 1 of the drawing, there is shown a package 10 including a heavy, bulky article, such as a refrigerator-freezer 12. The package 10 includes a skid 14 to which the article 12 is attached and a container 16 formed of corrugated fiberboard or other suitable packaging material that has sufficient size to enclose and protect the article 12. Along the entire length of each vertically extending edge 18 of the article 12, a corner post 20 is positioned to cushion and protect the edges of the article. The corner post 20 perferably extends slightly beyond the ends of the edges 18 and thereby also protects the upper and lower corners 19 of the article.

Each corner post 20 has a cross-section generally in the shape of the numeral 4 and spans the distance between a vertical edge 18 of the article and an adjacent inner corner 21 of the container 16. Each post 20 has a recess 22 that accepts and wraps around the edge 18 of the article and a vertex 23 which fits into the corresponding inner corner 21 of the container 16. Upon the application of an extreme or repeated lateral compressive force to the container during handling or transport, the corner post 20 may be wedged into the adjacent inner corner 21 of the container, but as a result of its improved design, it continues to cushion the article. Although four corner posts 20 are utilized in the package, they are identical in cross sectional design and only one is described herein.

FIGS. 2, 4 and 5 illustrate the features of the improved corner post 20 for cushioning and protecting the edge 18 of the article 12. The corner post 20 has sufficient strength to provide protection for the article against vertical and lateral compressive forces, yet it is sufficiently laterally flexible to prevent damage to the article from extreme or repeated lateral compressive forces. The corner post 20 has an outer covering 24, which is preferably formed of an integral piece of single wall, corrugated paperboard, which is readily commercially available at low cost and which can be easily and inexpensively fabricated to the desired form. Corrugated paperboard provides high strength corner posts which compare to wooden post constructions in column strength. Corrugated paperboard may be shipped to a packaging site in the form of flat sheets which can be fabricated as needed into the outer covering 24 having a cross-section in the shape of the number 4 and into reinforcing panels which are also a part of the posts.

The elongated blank 25 from which the outer covering 24 of the corner post 20 is formed is shown in FIG. 3. The blank 25 is divided by a score line 27 defining the recess 22 and by additional vertically extending score lines 29, 31 and 33 which complete the definition of the FIG. 4 configuration. When the blank 25 is folded about the score lines, there is formed respectively (from left to right) an inner base panel 35, a step panel 37 (hinged to the inner base panel and forming the recess 22 therewith), an hypotenuse panel 39, a vertex panel 41 and an outer base panel 43. The blank 25 takes the shape of the numeral 4 in cross-section when it is folded so the inner base panel 35 lies parallel to the outer base panel 43.

In the illustrated embodiment shown in FIG. 1, the inner base panel 35 lies adjacent one upstanding side surface 45 of the article 12 and the step panel 37 extends transversely to the inner base panel 35 and lies adjacent the front or rear surface 47 of the article. The inner base panel 35 and the step panel 37 define at their intersection the recess 22 which accepts the edge 18 of the article defined by the intersection of the surfaces 45 and 47. The hypotenuse panel 39 extends from the front or rear surface 47 of the article being protected to the adjacent inner corner 21 of the container 16. The vertex panel 41 which connects the hypotenuse panel 39 and the outer base panel 43, provides the corner post with a flat vertex 23 which abuts one sidewall 48 of the container 16 at the inner corner 21 thereof. The outer base panel 43 extends substantially parallel to the inner base panel 35 and is adapted to lie adjacent the inner surface of the other sidewall 49 of the container 16 which meets at the corner. Thus, a numeral 4 shaped corner post 20 is defined having an interior triangular-shaped aperture 51.

In order to provide the corner post 20 with longitudinal strength, so that a plurality of packages can be vertically stacked without damage to the artices, a reinforcement 53 is located interiorly of the outer covering 24. Preferably, the reinforcement 53 is formed of an integral piece of double-wall corrugated paperboard folded along a junction 59 into a shape that fits within the triangle-shaped aperture. An integral, folded panel in which the flutes run vertically provides good compression strength and thus good resistance to vertical compressive loads. Alternatively, the inner reinforcement 53 can be formed of a suitable plastic material or of honeycomb material, made of plastic or metal, capable of being folded in the same manner as corrugated paperboard and faced with a material such as kraft paper, resin impregnated paper, paperboard, plastic, or thin metal foil.

As shown in FIG. 2, this inner reinforcement 53 includes a first or outer base reinforcing panel 61, which is fastened to the inwardly directed face of the outer base panel 43, and a second or hypotenuse reinforcing panel 63, which is positioned adjacent the inwardly directed face of the hypotenuse panel 39. The junction 59 of the outer base reinforcing panel 61 and hypotenuse reinforcing panel 63 lies interiorly of the vertex 23. The relatively flat region of the vertex panel 41 accommodates the folded junction 59 between the outer base reinforcing panel 61 and the hypotenuse reinforcing panel 63 and also inhibits the corner post from cutting the container 16.

The outer base reinforcing panel 61 is adhesively secured along its surface to the outer base panel 43 from the base of the FIG. 4 to a point designated by the reference numeral 64. The point 64 is preferably spaced a distance from the vertex 23 at least equal to the width of the vertex panel 41. The hypotenuse reinforcing panel 63 is not adhesively secured to the hypotenuse panel 39. Of course if the inner reinforcement 53 were completely laminated to the outer covering 24, the post would have considerably more compression strength. However, such a corner post 20 would be so strong that it would not properly cushion the article upon application of an excessive or repetitive compressive lateral force. The inner reinforcement at the vertex 23 provides adequate resistance to vertical compressive force as a result of the good vertical compressive strength contributed by an integral, folded panel.

To provide still further column strength for the corner post, the inner reinforcement 53 includes a double-wall corrugated paperboard third or spacer panel 65, which is located between the outer base reinforcing panel 61 and the inner base panel 35. The spacer panel 65 is preferably adhesively secured to both the inner base panel 35 and to the outer base reinforcing panel 61 so that the corner post 20 is quite rigid in the vertical direction. The panel 65 may be formed by slitting the panel from which the reinforcement is formed and folding it at the slit, or it may be a separate piece that is suitably attached to the panel 61.

It is preferred that the post be fabricated using an adhesive although other fasteners might also be utilized. A conventional water-based adhesive for the assembly of corrugated fiberboard, such as sodium silicate, may be used. Organic synthetic resins, such as polyvinyl alcohol adhesive, isocyanate adhesive, and polyvinyl acetate adhesive, might also be used. The post could be assembled with staples or a combination of adhesive and staples. However, adhesive is preferably employed to unite the inner base panel 35, the spacer panel 65, the outer base reinforcing panel 61, and the outer base panel 43.

Preferably, the outer covering 24 of the corner post 20 is fabricated from the integral blank 25 of corrugated paperboard the flutes of which are disposed horizontally, which blank is suitably scored to provide the elongated, vertically oriented panels 35, 37, 39, 41 and 43. The flutes of the inner reinforcement 53, i.e. the outer base reinforcing panel 61, the hypotenuse reinforcing panel 63 and the spacer panel 65, are vertically disposed and provide the primary vertical strength of the corner post 20. The combination of the hypotenuse panel 39 wherein the flutes run horizontally and the inner hypotenuse reinforcement where the flutes are vertical has been found to excellently protect the article against compressive forces.

The hypotenuse panel 39 is divided by a score line 71 extending longitudinally thereof into two panel sections 73 and 75. The score line 71 and the score lines 29, 31 and 33 are preferably disposed on one face of the blank, that which becomes the interior of the corner post, and the score line 27 at the recess appears on the outer surface of the blank. However, the score line 71 may be placed on either face of the blank 25 as folding will take place along the line of weakness it provides. The hypotenuse panel 39 is adapted to fold at the score line 71 upon the application of an extreme or repeated lateral compressive force to the corner post 20 either by the shifting of the article 12 within the container 16 or by the squeezing of the package 10 by handling apparatus. This score line 71 permits the hypotenuse panel 39 to fold outward, thereby permitting the article 12 to shift somewhat within the container 16, but the article remains cushioned against the applied lateral compressive force. If this score line 71 were not provided in the corrugated hypotenuse panel 39, the corner post would have more strength to resist lateral deformation. However, a corner post which is so strong that it will not crush upon such application of lateral force may itself damage the article.

At about the same time as the hypotenuse panel 39 begins to fold outwardly at the score line 71, as a result of the application of extreme or repeated compressive lateral force, the hypotenuse reinforcing panel 63, which has less strength in the horizontal direction because of its vertical flutes, first crushes at the point where it abuts the step panel 37. The initial crushing of hypotenuse reinforcing panel 63, as the compressive lateral force is applied, assures that it reinforces the hypotenuse panel 39 so that the folding at the score line 71 can proceed uniformly. As the reinforcing panel 63 and the hypotenuse panel 39 are not laminated, the panels separate as the lateral force is applied. Upon the application of still greater force, the panel 63 eventually bends outwardly in an area generally adjacent the score line 71 in the panel 39 (as shown in FIG. 5). This bent panel 63 continues to support the hypotenuse panel 39 and the step panel 37 and thereby cushions the article 12 within the container 16. Because the hypotenuse reinforcing panel 63 separates from the hypotenuse panel 39 and both panels bend in the direction shown, i.e., outward, the aperture 51 in the post is maintained, thus indicating that the corner post 20 is continuing to cushion the article by maintaining spacing between the article and the walls of the container.

As shown in FIG. 1, four corner posts 20 are disposed within the container 16 along with the article 12 to form the package 10. The posts are located between each edge 18 of the article 12 and the adjacent inner corner 21 of the container 16, with each hypotenuse panel 39 extending between a front or rear surface 47 of the refrigerator-freezer and the respective inner box corner 21 (FIG. 4). As the article 12 moves closer to one interior surface of the container, either by shifting movement of the article within the container or by application of a lateral compressive force against the exterior of the container, the vertex 23 of the respective post is wedged into the adjacent inner corner 21. Initially, the corner post 20 resists the compressive force because of the inner reinforcement 53, the shape of the post, and the horizontal flutes of the outer covering 24. As the force reaches an excessive level, or if the force is repeated sufficiently to cause fatigue, the hypotenuse panel 39 begins to fold outwardly at the vertical score line 71. The hypotenuse reinforcing panel 63 then receives a greater portion of the compressive force, first crushing and then folding outwardly. As the reinforcing panel folds, it separates from the hypotenuse panel 39, but the reinforcing panel 63 remains generally in position between the vertex 23 and the step panel 37, as shown in FIG. 5. Although the edge of the reinforcing panel 63 is somewhat crushed, the aperture 51 remains, indicating that the article 12 remains cushioned within the container 16. The controlled yielding of the hypotenuse panel prevents total crushing from occurring which might allow the article to slide past the corner post and hit the container walls, where the article might be damaged. Moreover, not only is the column strength of the corner post 20 not impaired when the controlled yielding of the hypotenuse panel 63 occurs but the presence of an additional bend in the reinforcement may actually increase its strength.

Thus, it can be seen that the invention provides an improved lightweight container which includes cushioning material for protecting the corners and edges of an article. Furthermore, the invention provides an improved corner post useful in packaging a bulky and heavy article, the corner post having high columnar strength, yet being capable of cushioning the article upon the application of an extreme or repeated lateral compressive force to the container. The containers can be stacked even though the uppermost containers receive heavy articles which tend to crush the lowermost containers. The articles will be effectively cushioned against lateral compressive forces, such as those applied by squeeze-lift handling units.

FIG. 6 shows, as an alternative embodiment, a corner post 20a in which the apex of the FIG. 4 is exaggerated. The exaggeration is accomplished by increasing the dimension of the panel 41a of the outer wrap-around member. In this embodiment, instead of merely folding the inner member at the apex as shown in FIG. 4, an additional score line is used to provide a short fourth panel 62 in the inner member 53a which is hinged to panels 61a and 63a at the apex. Other than in the foregoing respect and in the placement of the score line 71a on the outer surface of the outer member 24a, the illustrated corner post 20a is substantially the same as that shown in FIG. 4 and functions in substantially the same manner as illustrated in FIG. 6A. The corner post 20a having such an exaggerated point is considered to be particularly effective in avoiding penetration or puncture through the sidewall 48 of the container 16 that could conceivably occur as result of extremely rough handling.

FIG. 7 shows a corner post 20b which is further exaggerated, compared to that shown in FIG. 6, to such an extent that the outer wrap-around member 24b actually forms a substantial rectangle. The panel 41b is made longer than the panel 41a in FIG. 6, and the panel 39b is slightly shorter to provide the rectangular configuration. In this embodiment, the inner member 53b, which has the vertically oriented flutes, remains substantially the same as the member 53 shown in FIG. 4. The cushioning effect is similarly created by providing the failure score line 71b in the panel 39b which extends between the sidewall 48 of the container and the parallel surface 47 of the article. As illustrated in FIG. 7A, the horizontal corrugations in the fiberboard from which the outer wrap-around member 24b is made retains sufficient resilience that, even after controlled failure occurs at the score line 71b, the post 20b supports and protects the article 12 packaged under all normal handling encountered thereafter.

FIG. 8 discloses a corner post 20c which is generally similar to the corner post 20b shown in FIG. 7 to the extent that the outer member 24c is formed with a portion having a generally rectangular configuration. However, in the corner post 20c, the direction of the corrugations in the outer and inner members is reversed as compared to that shown in FIG. 7. In the corner post 20c, the outer member 24c is vertically fluted whereas the inner member 53c has horizontal flutes. It is also noted that both the inner member 53c and the outer member 24c are made from double wall corrugated, thus inherently providing a thicker base and eliminating the employment of an additional panel, such as the panel 65 shown in FIG. 4. Although in the embodiments illustrated in FIGS. 4, 6 and 7, the outer material used was single wall corrugated, it should be understood that other suitable materials can be substituted therefor.

Inasmuch as, in the corner post 20c, the horizontally fluted member is on the interior, the controlled failure score line 71c is located centrally of this member on the diagonally extending panel 63c. Preferably, the failure score line 71c divides the panel 63c in half; however, placement of the failure score line a distance either side of the mid-point not greater than about 10 percent of the transverse width of the panel 63c is considered acceptable. As shown in FIG. 8A, when the force imposed on the package exceeds the predetermined amount, bending occurs in the panel 63c at the failure score line generally away from the article 12 being protected, as hereinbefore generally described with regard to the horizontally fluted outer member in respect of the corner post 20 shown in FIG. 5. In this case, it is likely that some crushing of the vertically fluted outer member 24c will occur at the junction between the panel 37c and the panel 39c, followed by a buckling of the panel 39c at some central point, generally as illustrated. As soon as the force which caused the controlled failure to occur is removed, the inherent resiliency of the double wall, horizontally fluted material causes it to try to regain its original flat orientation and thus continues to provide support for the article 12 along that edge thereof.

Although several forms of the invention have been shown and described, it should be apparent that various additional modifications might be made therein without departing from the scope of the invention.

Various of the features of the invention are set forth in the following claims.

Claims

What is claimed is:

1. An integral, elongated, vertical corner post for cushioning and protecting a vertical edge of an article, the corner post having an outer covering formed of corrugated fiberboard having horizontal corrugations, the outer covering comprising an elongated inner base panel adapted to lie adjacent a first surface of the article, an elongated step panel disposed transversely to said inner base panel and adapted to lie adjacent a second surface of the article, an edge of the article formed by the intersection of the first and second surfaces being received by a recess formed by the intersection of said inner base panel and said step panel, an elongated outer base panel disposed substantially parallel to said inner base panel, and elongated panel means interconnecting said step panel and said outer base panel and forming a vertex at its intersection with said outer base panel, said vertex being designed to fit into the corner of an outer container in which the corner post is employed, wherein the improvement comprises said panel means having an elongated line of weakness disposed therein and located such that said panel means will fold outward at said line of weakness upon the application of lateral compressive force to thereby cushion the edge of the protected article against the force.

2. A corner post according to claim 1 further comprising reinforcement means located interior of said outer base panel and such panel means and formed of corrugated material having vertical corrugations, said reinforcement means protecting the article against vertical compressive force.

3. A corner post according to claim 2 wherein said reinforcement means comprises a first reinforcing panel secured to the interior face of said outer base panel and a second reinforcing panel integral with said first reinforcing panel and positioned adjacent the interior face of said panel means, said second reinforcing panel being separable from said panel means when said application of lateral compressive force causes said panel means to fold outward at said line of weakness, said second reinforcing panel preventing the collapse of said folding panel means.

4. A corner post according to claim 3 further comprising a third reinforcing panel positioned between and secured to the inwardly directed faces of said inner base panel and said first reinforcing panel.

5. A corner post according to claim 3 wherein the intersection between said first and second reinforcing panels is located immediately interior of said vertex.

6. A corner post according to claim 3 wherein said panel means includes a vertex panel which is disposed substantially perpendicular to said outer base panel to which it is hinged.

7. A corner post in accordance with claim 3 wherein said outer base panel is adhesively attached to said first reinforcement panel over a major portion of its area but not including the region adjacent said vertex for a width at least equal to the width of said vertex panel.

8. A corner post according to claim 6 wherein said panel means includes a hypotenuse panel which extends from said vertex panel to said step panel and wherein said line of weakness is disposed not farther from the midpoint of said panel than about 10 percent of the width of said hypotenuse panel.

9. A corner post in accordance with claim 7 wherein said reinforcement means includes a short fourth panel hinged between said first and second panels lying adjacent the interior surface of said vertex panel.

10. An integral corner post for cushioning and protecting a vertical edge of an article within an outer container of generally rectangular horizontal cross section, which corner post is formed of a corrugated fiberboard member having horizontal corrugations and a corrugated member having vertical corrugations, said corner post being adapted for disposition in surface-to-surface contact with first and second perpendicular surfaces of the article being protected and first and second inner sidewalls of the outer container, said corner post being designed to extend longitudinally for at least a major portion of the height of the protected article, said vertically corrugated member being wrapped outside said other member and having an outer base panel adapted to lie adjacent the first sidewall of the outer container, said outer base panel being secured along a major portion of the opposite surface thereof to an outer base reinforcing panel of said inner member, said outer member having a vertex panel hinged to said outer base panel which is adapted to lie adjacent the second sidewall of the container, having panel means hinged to and extending from said vertex panel to a hinged step panel that lies adjacent the second surface of the protected article, and also having an inner base panel hinged to said step panel and being adapted to lie adjacent the first surface of the protected article, said inner horizontally corrugated member having a diagonal panel hinged to said outer base reinforcing panel thereof and extending generally from the intersection of said outer base panel and said vertex panel to the intersection of said panel means and said step panel, said diagonal panel containing a longitudinal line of weakness in a central location therein, which line of weakness causes controlled failure to occur resulting in outward folding of said diagonal panel to prevent damage to the article being protected while continuing to support said vertically corrugated member and cushion the vertical edge of the article.

11. A corner post in accordance with claim 10 wherein said line of weakness is located not farther from the midpoint of said diagonal panel than about 10 percent of the width of said diagonal panel.