BACKGROUND OF THE INVENTION

Description of the Prior Art [1] Many non-liquid packaging containers are formed from blanks of flexible material such as corrugated board. To reduce shipping costs, these containers are often transported unassembled for subsequent assembling by the end user of the containers. If the end user is a manufacturer or seller of goods, that end user will often times have dedicated equipment for assembling the container. However, if the end user is a consumer of the container, such user rarely has this dedicated equipment at his or her disposal. In its place, the user generally must usually do one or more of the following: insert tabs into slots while forming the container; establish overlapping panels that are resistant to deconstruction largely due to the interference between the panels and the other portions of the container; apply adhesives (e.g., glue or tape) or mechanical fasteners (e.g., string or staples).

SUMMARY OF THE INVENTION

[2] The invention is directed to a user assembled container constructed from a generally planar blank of bendable material wherein instrinsic tabs and slots, or extrinsic mechanical fasteners or forms of binding materials such as tape or line need not be used in order for the assembled container to retain its form. The blank may be constructed from any bendable, naturally occurring or synthetic polymer, but is preferably constructed from corrugated cellulose where the corrugated cellulose has two face liners separated by a fluted medium. [3] While many embodiments of the invention concern containers having a plurality of side walls, the invention is not so limited. Cylindrical containers, which by definition have only a single side wall, also benefit from incorporation of the invention, as will be discussed in greater detail below. In addition, multi-sided boxes can be formed from a multitude of blank configurations; while the invention is exemplified by describing only a few of such configurations, the skilled practitioner will appreciate that for any given blank it need only have at least one

portion thereof that overlaps another portion thereof when assembled into a container.

[4] Unlike prior art containers wherein extrinsic materials in addition to the blank are needed to retain the form of the assembled container, and unlike prior art containers wherein intrinsic structures such as tabs and slots are used to retain the form of the assembled container, containers according to the present invention are self-sustaining after assembling the blank into the desired container form. This self-sustaining feature is accomplished by coating at least selective portions of the blank with a cohesive material, such as a latex cohesive. A cohesive differs from an adhesive in that cohesive materials only bond with themselves as opposed to any other materials. Beneficially, no release films are needed. Thus, at least some of the selective portions of the blank are characterized as having an overlapping relationship when the blank is assembled into the desired container form. It is to be understood that additional portions of the blank may be coated for reasons that will be described in more detail below.

[5] The selective portions are preferably on just one side of the material that forms the blank. If only one side of the blank is coated with the cohesive, whether entirely or selectively, the coated blanks may be stacked without concern over unintentional bonding to adjacent blanks (presuming that all blanks are oriented in a similar manner to each other).

[6] In addition to the elimination of conventional fabrication means such as adhesive tape, strings or lines, and tabs/slots, use of a cohesive has several other advantages. One advantage is that if an entire surface of the blank is coated, it forms a suitable moisture barrier, thus ensuring that the contents of a subsequently assembled container remain unaffected by external moisture. Alternatively, moisture containing products can be placed into the container without concern over material degradation or moisture escapement. Another advantage to the use of a cohesive coating coextensive with one side of the blank is that the cohesive coating greatly increases the surface's coefficient of friction without bonding taking place, thereby greatly reducing the tendency of objects to slip, such as documents placed within the volume of the container, or the container moving relative to supporting surface if coated on the exterior surfaces of the blank.

[7] As those persons skilled in the art will appreciate, lip flaps (or additional lip flaps) can be oriented to be present on the exterior of the assembled container, and exposed to the environment. By using a lid structure not including the linking portions, for example, the side walls of the lid structure can be folded over the exposed lip flaps, which also include a cohesive coating, to thereby create the desired bond. In such embodiments, multiple uses are not encouraged. However, if the user desires to create a hinged lid structure from a separate lid blank, linkage on one side of the container is both desirable and possible.

[8] In view of the foregoing and by way of example only, a basic blank for a conventional container according to the invention comprises a substantially planar sheet of material having a bottom wall, first and second sidewalls extending in opposing directions from the bottom wall, third and fourth sidewalls extending in opposite directions from the bottom wall, and preferably although not necessarily first and second lip flaps extending from two opposing sidewalls. Additionally, linking portions extend from one sidewall to an adjacent sidewall, throughout. A cohesive is present on at least selected portions of a first side, a second side, or both first and second sides of the blank in locations determined to be in overlapping relationship when the blank is assembled into a container. The optional lip flaps can operate to retain the mated linking portions during assembly of certain embodiments; while their presence is not necessary to operation of the invention, for those embodiments wherein cohesive is present on only a single side of the blank (whether selectively or wholly) their use is desirable for proper formation and retention of the container shape. Preferably, each linking portion defines a cutout for those embodiments wherein two of the sidewalls have a relatively small width compared to the depth or height of the container.

[9] A benefit to the incorporation of the linking portions is that the resulting container has increased vertical load bearing properties and there is less waste. Compared to single-walled constructions, the illustrated embodiments have a 50% increase in vertical compression resistance. Moreover, because of the illustrated embodiments' design, significantly less material is used for construction of the container, whether inherently or with respect to manufacturing waste.

[10] In preferred embodiments, bend assisting means are provided at the interfaces between all adjoining portions to assist in bending the portions relative

to one another. Those persons skilled in the art will appreciate that such means comprise scoring, slitting, crushing, creasing and/or perforating the interfaces. In addition, such assisting means are used for each linking portion, with a preference for perforation or material cutout given the near 180° intermediate fold needed as opposed to the preferred 90° bends used for the wall interfaces. Lip flaps may include a two parallel bend assisting means to take into account the thickness of the overlapped material where appropriate.

[11] From a manufacturing perspective, the cohesive can be applied to material after formation of the blank, and in the case of corrugated material, it can be applied to one liner prior to construction of the corrugated material. While rod coating is the presently preferred means of application (particularly for wholly coating the liner), other means well known in the art are also applicable. Thus, using corrugated material as an example, the manufacturing process comprises coating a liner, creating the corrugated material using a corrugator, and cutting the blank to a desired shape (scores, slits, perforations and the like can also be established at this step). If one liner is wholly coated and that liner forms the interior surfaces of the container, then it may also be desired to imprint the other liner with graphics. Applying graphics to the outside liner is also possible if selective application of a cohesive is carried out, although if cohesive is selectively applied to the outer liner, then manufacturing complexity increases.

[12] While the foregoing description has been directed to a simple five-sided container, the invention is broadly directed to any container that is to be assembled by a user after manufacturing of the blank. Thus, any single or multi- walled container is considered to be within the scope of the invention, so long as such container employs application thereto of a cohesive at selected overlapping portions of the container for forming a self-sustaining container from a blank.

BRIEF DESCRIPTION OF THE DRAWINGS

[13] Fig. 1A is a combined top (left side), and split top (upper right quadrant) and bottom (lower right quadrant) plan view of a first embodiment of a container blank according to the invention showing fold lines and alternative selective areas

(one sided application on the left or two sided application on the right) for cohesive application;

[14] Fig. 1 B is view similar to that of a Fig. 1 A, but for a first embodiment of a Hd blank according to the invention showing fold lines and selective areas for cohesive application;

[15] Fig. 2 is a top plan view of a first embodiment of a combined container and lid blank according to the invention showing fold lines;

[16] Fig. 3 is a perspective view showing a schematic illustration of the embodiment of Fig. 1 A (shown without lip flaps for clarity) in a first partially folded and assembled stage;

[17] Fig. 4 is a perspective view showing the embodiment of Fig. 3 in a second nearly assembled stage;

[18] Fig. 5 is a perspective view showing the embodiment of Fig. 2 in a first partially folded and assembled stage; [19] Fig. 6 is a perspective view showing the embodiment of Fig. 5 in a second, assembled stage; and

[20] Fig. 7 is a plan view of an alternative embodiment to that of Fig. 1 A according to the invention showing fold lines and a plurality of notches defined by the linking portions to eliminate undesired overlap when constructing containers of certain dimensions.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Turning then to the several Figures, wherein like numbers designate like parts, and more particularly to Fig. 1 A, a first embodiment of the invention is shown. Each container 10 is preferably constructed from a blank of double liner corrugated board. In the illustrated embodiment, blank 20 has inside surface 22 and outside surface 24. In addition, blank 20 has bottom wall 30, sidewalls 40a- 4Od, lip flaps 50a and 50b, and linking portions 60a-60d. Each of these portions is coextensive with an adjacent portion, and is preferably delineated by score line 70.

The cross hatching shown in Fig. 1A identifies the preferred minimum area to be coated with a cohesive for this blank configuration and still obtain functional self-sustaining structure. As will be described in detail below, manipulation of the sidewalls and linking portions cause these cohesive areas to lie in opposition when constructing the container, thereby permitting the opposing areas to be firmly bonded to each other. The left half of Fig. 1A illustrates cohesive zones when only portions of one side (preferably inside surface 22) of blank 20 are selectively coated with cohesive. The right half of Fig. 1A illustrates cohesive zones when both inside surface 22 and outside surface 24 of blank 20' are selectively coated with cohesive, where the coatings are symmetrical about the horizontal axis "H".

!n order to assemble blank 20 into container 10 (see Fig. 4), it is necessary to contact cohesive zone 62a to cohesive zone 42c, and cohesive zone 62b to cohesive zone 44c by folding sidewall 40a inwardly along score 70a and folding sidewall 40b inwardly along score 70b. Preferably at the same time, sidewall 40c is folded inwardly along score 70c, and sidewalls 40a and 40b are folded outwardly by back folding on perforations 66a and 66b, respectively. The same procedure is applied with respect to the cohesive zones, flaps and linking portions on the other side of blank 20. A partially assembled container 10 is best shown in Fig. 3. Finally, lip flap 50a is folded inwardly towards inside surface 22 of flap 40c, wherein cohesive zone 52a contacts cohesive zones 64a and 64b, thus securing linking portions 60a and 60b.

A similar approach is taken with respect to container 10', except the cohesive zones are located in other overlapping areas of blank 20'. In this embodiment, contacting cohesive zones 66d and 68d located on outside surface 22 requires inward deflection of sidewalls 40b and 4Od. Linking portion 6Od is then folded towards inside surface 22, thereby exposing cohesive zone 64c for subsequent contact with cohesive zone 52b when lip flap 50b is folded inwardly towards sidewall 4Od, as was the case with container 10. Figure 1 B shows lid 100, and its respective cohesive zones, scores and perforations. In all relevant respects, it is functionally similar to blank 10 and container 20. However, because its sidewalls are comparatively short, the cohesive zones are coextensive with the end sidewalls and linking portions.

The embodiment shown in Fig. 2 illustrates an integrated container and lid. In this embodiment, inside surface 22" of blank 20" is wholly coated with cohesive, thereby establishing a highly water resistant interior, suitable for storing high moisture content items. The construction of container 10" is best shown in Figs. 5 and 6, and generally follows the manipulations described with respect to the embodiments shown in Figs. 1A and 1 B.

In certain embodiments, it is desirable to minimize the length of the diagonal edge corresponding to the perforations of the linking portions when the depth of sidewalls 40 is large and the length of sidewalls 40c and 4Od is comparatively short. If this is not done, the distal end of the diagonal edge of one linking portion will overlap the distal edge of the adjacent linking portion, as those persons skilled in the art will appreciate. To avoid this problem, notches 80 are formed in linking portions 60, as best shown in Fig. 7. In this manner, when linking portions 60 are adducted and pivoted to contact with respective sidewalls ^ΦΘ&€ttd?4Bd^#ιe^i^ιl^encls of the linking portions wi|l not overlap one another.