FIELD OF THE INVENTIONThe invention relates to the structure and production of corrugated paperboard and similar containers using fold-and-glue production line techniques. The containers are produced from strategically placed folds and adhered panel surfaces of an integral die-cut blank. During container erection, panels coupled by fold and glue connections are hinged on axes at folds, for opening the container from a knocked-down flat state to an open state having shelves.
BACKGROUND OF THE INVENTIONCorrugated craft and paperboard containers are made from one or more pieces of flat stock that are typically die cut into shapes that define various panels. The panels define the container top and bottom panels, side walls, front and back, and any internal reinforcements, partitions and other structural members that are needed to form the particular container structure.
Preferably, the container consists essentially of the minimum number of discrete pieces that are necessary to provide the walls and other structural members that make up the container. Ideally, a container might consist of a single integral flat sheet wherein all the structural members are panel areas defined between spaced folds in the sheet or adjacent to edges at which tabs mechanically or adhesively join the respective panels to other panels. Preferably, a container is erected or assembled with a minimum number of manual or mechanical motions.
Typically, containers comprise one or more sheets where structural panels exist between spaced folds. An overlapping strip or panel is typically glued, taped, or affixed by a fastener to an adjacent panel. Alternatively, a tab might be inserted into a slot or otherwise captured to affix panels in a shape defining the container. The panels form a closed perimeter around a space within the container, and may include partitions, reinforcements, doubled thicknesses and the like at different places. The various panels typically include side walls, a top and/or bottom, etc., at least partly bounding a volume as a full or partial enclosure when in place.
Advantageously, empty containers are supplied in a collapsed or flattened parallelogram state (known as knocked-down-flat or “KDF”), for efficient storage, handling and shipping. Before packing with contents, the containers are opened out into a hollow form wherein the panels are folded to reside in orthogonal planes. Parallel panels are generally spaced from one another.
Such containers can be more or less complicated, and the challenge to design a container with only one or a few integral sheet pieces is increasingly greater for structures that require more structural members. For complicated container structures, multiple integral pieces are often needed and/or a large number of assembly operations. A very simple container known, for example, might consist of four integrally connected side walls, each of which has a top and bottom flap. More complicated containers may have doubled-over panels, reinforcing folded parts, inter-engaging tabs and slots, volume partitions and other features.
Paperboard and corrugated containers advantageously are produced by fold-and-glue production line techniques. A blank is oriented and cut into a pattern that includes adjacent panel areas. Preferential fold lines are formed between panels by perforations, slits or crimp lines. The integral die cut sheets are fed through a fold-and-glue production line, such as those available from Bobst Group, Inc. of Roseland, N.J. As the blanks are advanced, adhesive is applied to limited areas where surfaces are to be adhered. Guides and rollers hold and fold-over certain panels in a designed order so that the panels are adhered where necessary. The containers that emerge are in a knocked down flat (KDF) state for shipping or storage, and are ready to be erected into their final configuration prior to being loaded with contents. Erection comprises applying pressure manually or using a machine that causes parallel panels in KDF state to become displaced, and panels abutting one another at folds to hinge around the axis of the fold, thereby articulating the panels into a final shape where typically certain panels are spaced and parallel and other panels are adjacent and perpendicular.
A simple regular slotted carton (RSC) version of such a container might comprise a blank of four rectangular panels serially abutting one another at folds, wherein the panels are to be front/rear and side walls of the container, and oppositely protruding flaps are to overlap to form the top and bottom. The fold-and-glue line affixes the free ends of the first and last serially abutting panels at a glued strip, while folding the blank in half. Pressing inwardly from diagonally opposite corners opens the container from a flattened parallelogram into a rectilinear box, whereupon folding the flaps inwardly by 90° from their adjoined panels completes the erection. In relatively more complicated full or partial containers, various panels may need to be folded in appropriate directions in appropriate order. Various tabs may need to be inserted into respective slots and so forth.
Containers as described can be used for displaying items or goods for the consumers at the point-of-sale location. Minimizing the effort and complication required to erect and set up the containers is an important factor for the viability and success of the particular container design. Thus, the number of parts required to erect or assemble the containers from their KDF configuration is an important element in the acceptability of the container design.
Generally, a container design is most efficient if most or all of its parts are integral parts and extensions a single flat blank, i.e., integral parts of the same sheet of material. A container that comprises multiple discrete parts may still be relatively efficient if the parts are adhered or otherwise captured in one anther. However, separate parts such as separate lids, loose partitions, shelves, reinforcing inserts and the like require attention to inventory, manual assembly steps and other complications during the production, erection and set up of the container. Such separate parts are not desirable. However it is difficult to design a complex container in one piece. It is particularly difficult to do so if the container has structural complications such as tiered shelves or if the container is expected to have movable functional elements such as self erecting parts.
In a container that has multiple discrete pieces, it is possible to exploit relative movement between the pieces. In commonly owned U.S. patent application Ser. No. 11/623,395, filed Jan. 16, 2007, a container is disclosed wherein tiered shelves are provided, cut partly from a front panel along fold lines, and attached at the back to a discrete separate panel that is carried within the container. The separate panel is movable in a direction perpendicular to the longitudinal extension of the shelf fold, to cause the tiered shelves to erect into a horizontal orientation. The container can be produced with a fold and glue production line, but two distinct integral parts must be provided and handled for alignment, gluing, etc. This general sort of tiered shelf container, known in the trade as a “wing,” is useful as a merchandise display. It would be advantageous to provide a wing container that has similar functional advantages but does not require multiple discrete parts.
SUMMARY OF THE INVENTIONIt is an object of this disclosure to provide ways to make and structure a complex container in a tiered shelf arrangement that is self erecting, wherein the shelf and shelf erecting elements preferably are parts of a single integral die cut piece of paperboard, corrugated paper or the like. The product is produced using a fold and glue production technique where the container exterior walls and the shelves are glued in place during manufacturing the shelves are erected in the same movement by which the container is erected.
It is another object to improve on known tiered shelf wing container structures by exploiting the linear displacement or translation that occurs between opposite sides of a parallelogram when the parallelogram is erected from a flat to rectilinear shape. For this purpose, a fold and glue container structure is provided wherein plural panels of an integral sheet abut one another along parallel fold lines, and define (in order) a first endwall, the front, a second endwall and the back. One or preferably several shelves are affixed between the front and the back at folds that are likewise parallel to the fold lines of the integral sheet. In this way, opening out or erecting the container from a knocked down flat state to a rectilinear box shape moves the shelves into position. Moreover, by providing bellows or gusset folds at certain corners joined to lateral sidewalls, simply hinging the lateral sidewalls perpendicular to the plane of the front and/or back erects the container and the shelves in one motion.
The container has a rectilinear shape along its outer surfaces when erected (parallel opposite top and bottom, front and back and opposite lateral sides) and erects from a flattened parallelogram in section (viewed from either lateral side) into a rectangle. The axes of the parallelogram on which the outer panels hinge to erect the container (namely the four folds where the front and back panels joint the top and bottom panels) are parallel to axes at which each of the shelves folds relative to the front and rear panels. The shelves are attached to the front and rear at folds and glued fold flaps. Whereas the hinging axes are all parallel, erecting the parallelogram of the outer panels also erects the smaller parallelograms defined by the shelves and the portions of the front and rear panels between the shelves.
The container does not have any particular fixed or required orientation. Nevertheless, in order to distinguish the panels and parts relative to one another, in this description the “front” is used to refer to the panel where openings are provided between the shelves. The “rear” is the panel behind the shelves and may be a solid wall. The lateral sidewalls extend between the front and rear on the opposite sides, generally at the ends of the shelves. The top and bottom are referred to as endwalls, because the container might be placed with either of its ends facing up, and still has a substantially similar arrangement of vertically tiered shelves that are open to the front and hinged to the back.
Therefore, a folded and glued container disclosed herein comprises a plurality of panels defining a back panel, a front panel opposite the back panel, and two longitudinally opposite endwall panels (which can be deemed the top and bottom) joined to the back panel and the front panel. The plurality of panels further comprises two laterally opposite sidewalls joined to one of the front and back panels, and removably coupled to the other of the front and back panels. When the container is erected, the plurality of panels define an internal space of the container.
The one of the front and back panel preferably is integrally joined at a fold line with to a first one of the two endwall panels and the other of the front and back panels is attached to the second of the two endwall panels by an glued strip, also adjacent to a fold line. In this way, the front, back and endwalls form a parallelogram in cross section. The parallelogram is flat when the container is in a KDF state and is opened into a rectangle when the container is erected. Diagonally inwardly folded bellows panels can be provided, extending between and integrally joined to one endwall panel and its adjacent opposite sidewalls. Thus when the sidewalls are hinged or pivoted over into a position covering the lateral sides of the container, the bellows panels pull said endwall into an orientation perpendicular to the front and back panels. The container is thereby erected from the KDF state to the erected rectangular state. In the erected state, the free edges of the sidewalls can be captured by tab and slot couplings to one of the front and back panels.
Preferably, all the foregoing panels are cut out from a single flat blank and are processed by fold-and-glue steps, in manner a described in detail below. However it would also be possible to provide a structure that is integral before erection by virtue of the fact that the respective non-integral panels or parts thereof have been fixed permanently to one another by gluing them into one affixed body. In any case, the result is that when the sidewalls are hinged perpendicular to their knocked-down-flat KDF configuration to cover the sidewalls of the container, the sidewalls erect the two endwall panels and the back panel into a rectilinear box.
Spaced between the endwall panels, at least one and preferably plural shelf panels are provided. Each shelf panel is cut out from the front panel except along a fold line parallel to the top or bottom endwall. At the fold line, the shelf meets the front panel at a right angle in the erected state. The edge of the shelf opposite from the fold line has a glue strip, also making a right angle in the erected state, and the glue strip is affixed to the back panel at the same height as the fold line at the front panel. Each of the shelf panels and the endwalls remain parallel in parallelogram cross section. When the container is erected, the flattened parallelogram defined by the front, back and endwall in the KDF container, open into a rectangular cross, and likewise draw the shelves into a position perpendicular to the front and back panels.
BRIEF DESCRIPTION OF THE DRAWINGSA number of additional objects and aspects are apparent from the appended description and the associated illustrations of preferred embodiments, wherein:
FIG. 1 is a perspective view of an erected container according to an exemplary embodiment;
FIG. 2 is a plan view of the die-cut blank for the container ofFIG. 1;
FIG. 3 is a plan view of an interim configuration of the die-cut blank ofFIG. 2 that is being folded and glued into a KDF container blank;
FIG. 4 is a plan view of a KDF container blank made from the die-cut blank ofFIG. 2 by a fold and glue machine;
FIG. 5 is a perspective view of the KDF container blank ofFIG. 4; and
FIGS. 6-9 are sequential perspective views of the KDF container blank ofFIG. 5 in the process of being erected in to the container ofFIG. 1.
All drawings are schematic and not to scale. Like structures are shown in like reference numbers.
DETAILED DESCRIPTIONAs will be appreciated, terms such as “horizontal,” “vertical,” “left,” “right,” “up,” “down,” “top,” “bottom,” “front” and “back,” (etc.), used as nouns, adjectives or adverbs (e.g. “horizontally,” “rightward,” “upwardly,” “downwardly,” etc.) that appear in this description refer to the orientation of the structure of the invention as the container of the invention happens to be oriented in the particular drawing figure under consideration, with that figure facing the reader. Such terms are not intended to require or limit the invention to a particular orientation. Similarly, the terms “longitudinal” and “lateral” generally refer to the orientation of surfaces or other structures relative to an axis of elongation or axis of rotation, as appropriate.
The terms “connected” and “interconnected”, when used to describe the relationship between two or more structures, denote that the structures are secured or attached either directly or indirectly through intervening structures and include movable connections such as pivoting connections. The terms “integral”, “integrally connected” or “integrally joined” when used to describe the relationship between two or more structures generally means that the structures are comprised of a single piece of material. Often, however, two adhered or otherwise permanently affixed elements function in the same way as an integral single piece. The term “operatively” means that the foregoing direct or indirect connections between such structures allow the structures to operate as described and intended by virtue of such connection.
Lines representing fold lines are shown in the drawings by broken and solid lines that represent lines along which the material can be weakened or caused preferentially to fold by any of various means. For example, corrugated or other material can be compressed along a thin line defining a fold, or can be cut part way through along the line, or cut all or part way through the line at spaced intervals. Each of these and similar techniques form lines along which the material is folded or made readily foldable, in the knocked-down flat (“KDF”) container blank and/or in the erected container.
In the drawings, portions of joints in which glued surfaces are exposed to view and discussed in this description are sometimes shown in the relevant figures by “XXX” patterns, representing an area to which adhesive has been or will be applied. Areas where the glue on a rear face of a respective panel is relevant are at times shown in broken line “XXX” patterns, indicating an adhering surface on a side opposite from the side shown (i.e., the backside).
Referring toFIG. 1, a folded and gluedcontainer100 according to an embodiment is shown in an erected configuration. Thecontainer100 is a generally rectilinear box container comprised of six major panels defined by aback panel10, longitudinally opposite endwalls20a,20b, afront panel40 opposite from theback panel10 and two laterally opposite sidewalls30a,30b.
Thefront panel40 comprises a plurality offront face panels44a,44b,44c, and44d, which are spaced by gaps corresponding to locations at which theshelf panels60 are folded 90 degrees relative to thefront panel40, and from the front to the back to define useful areas within the volume of the container for supporting items (not shown) to be displayed on the shelves.
The front face panels44a-44dare portions that are cut along one line from a continuous length for the front panel in the die-cut blank100a, and fold relative the plane of the front panel along a line spaced from the fold. This aspect is shown inFIG. 2. The front face panels44a-44dremain in the plane of the front panel, attached by a fold to one edge of therespective shelf panel60. The shelf panels are separated by die-cutting from the integral sheet of thefront panel40 at the other edge.
Themajor panels10,20a,20b,30a,30b, and40 substantially define the internal space of the container, knocked down flat when initially produced, and opened out when the container is erected. As the container is erected from its KDF state, theshelf panels60 likewise hinge, remaining parallel to the endwalls, to form shelves.
In the configuration and/or orientation illustrated inFIG. 1, the front face panels44a-44dextend upwardly perpendicular to the horizontal surface of their associatedshelf panels60. In this embodiment, the fold joining the shelf to the associated front face panel is at the lower edge of the front face panel. The face panels44a-44dfunction as a front fence edge for each of the shelves and prevent items displayed on the shelves from sliding off. It is also possible to put the fold at the upper edge of the front face panel, which leaves the upper surface of the shelf unobstructed at the front.
FIG. 2 is a plan view of a die-cut blank100afor thecontainer100, according to a preferred embodiment wherein the container is cut from a single integral flat blank sheet of stock material. As discussed above, it is also possible to provide a blank that comprises affixed integral portions of or two or more smaller blanks.
The die-cut blank100acan be cut, for example, from a sheet of corrugated craft board, paperboard or other suitable sheet material. A number of thicknesses can be die cut in a single step. Preferably, the die-cut blank100ais cut out individually so that fold lines in the die-cut blank can be appropriately scored, creased, compressed or perforated at the same time that the perimeter of the die-cut blank is parted away from the blank sheet. All fold lines in the die-cut blank100aare appropriately scored, creased, compressed or perforated to allow the two adjacent panels that are joined along a particular fold line can be preferentially folded in a desired direction.
The shelf panels60 (advantageously two or more shelf panels are provided) are cut out of the front panel and form shelves. In this illustrated example, threeshelf panels60 are die-cut formed from thefront panel40. Each of theshelf panels60 is integrally joined to the front face panels44a-44dalong afold line6fwhile cut or detached from the front face panels44a-44dalong the die-cut line64. Each of theshelf panels60 is provided with one or more glue-tab portions62 for attaching to theback panel10 during the interim assembly into the KDF container blank. In the illustrated example, the glue-tabs62 are configured as a single tab for each of theshelf panels60 extending for the lateral length of the shelf. However, the glue-tabs62 can be configured as more than one tab pershelf panel60. Each of theshelf panels60 has a depth defined as the distance between thefold line6fjoining the shelf panel to the front panel and thesecond fold line8fjoining the one or more tabs to the shelf panel. This depth of the shelf panel is substantially equal to the distance between the front panel and the back panel when thecontainer100 is erected.
Optionally, a portion of the sidewalls30a,30badjacent to each of theshelf panels60 is removed during the die-cut process leaving behind openings H. As shown in the fully assembled view ofFIG. 1, these openings H form decorative openings along thesidewalls30a,30band may be cut into any variety of desired shapes.
The various panels of thecontainer100 described above can be seen in the die-cut blank100a. The die-cut blank100acomprises theback panel10 that is integrally joined to afirst endwall20balong afold line1f. Thefirst endwall20bis joined to thefront panel40 along afold line5f. Thefront panel40 is joined to a second endwall20aalong afold line2f. The second endwall20ahas aglue application region23 to which glue is applied by the fold and glue machine and attached to thetab14 of theback wall10 during the assembly into a KDF container blank100bshown inFIG. 4. These fold lines define parallel hinging axes for the parts that abut said fold lines.
Bellows panels or gusset fold joints25 are provided, extending between the second endwall20aand thesidewalls30a,30bso as to render the front/back and endwall panels self erecting when the sidewalls30a,30bare hinged to 90 degrees from their abutting major panel (in this example, the sidewalls abut at a fold to the front panel). Thebellows panels25 are tab-like structures extending between two orthogonally oriented panels near a corner of a rectilinear container that enables automatic or coordinated erection of the joined panels when one of the two joined panels are raised. Each of thebellows panels25 includes adiagonal fold line7fthat divides the bellows into two substantially triangular portions. One triangular portion of each of thebellows panels25 is integrally joined to the endwall20aalong a side edge defined byfold lines12f. This triangular portion is not glued. The second triangular portions of the gusset fold joints25, across thediagonal fold line7f, is adhered on a side that is folded under and bears against theadjacent sidewalls30a,30bwhen the die-cut blank100 is glued and folded into the KDF container blank100b. Thus, the second triangular portions are noted with “XX” symbols showing the areas that are glued.
The die-cut blank100ais preliminarily assembled by processing the blank100athrough a fold and glue machine to accomplish successive steps wherein glue is applied and various panels are folded over and compressed against other panels where the glue surface adheres and sets. As the die-cut blank100aadvances through the fold and glue machine, adhesive is applied by roller, spray or other techniques to respective parts that need to adhere. Panels, flaps or strips that need to be folded over are urged by to advance in a feed direction by drive rollers, and pass along ramp-like deflectors that turn and fold the necessary parts around crease lines. Over and under rollers compress the folded over panels. The container blanks are processed one after another and stacked, which further compresses the adhered surfaces.
The fold-and-glue process as described may be carried out by fold-and-glue machines, such as those available from Bobst Group, Inc. of Roseland, N.J. Fold-and-glue machines apply adhesive to pre-selected areas of the die-cut blank and preliminarily fold over pre-selected panels, and are generally reconfigurable to run containers of different sizes, different numbers of shelves and other variations. The end result is an assembled but knocked down flat KDF container blank100b, shown inFIG. 4.
During the process of gluing and folding the die-cut blank100ato produce the KDF container blank100b, the glue-tab areas62,23 and the glue area portion of thebellows panels25 are glued. Theback panel10 is then folded along thefold line1fand attached to the glued-tab areas62 of theshelf panels60. This interim stage is illustrated inFIG. 3. The glued-tab areas62 are shown in broken X lines under the folded overback panel10. Next, theendwall panel20ais folded along thefold line2fover onto theback panel10 such that the glued-tab23 on theendwall panel20aoverlaps thetab14 of theback panel10 and is glued to thetab14. Because thebellows panels25 on either side of theendwall panel20aare integrally joined to theendwall panel20a, they also get folded along thefold line2falong with theendwall panel20a. Thus, the glued portions of thebellows panels25 get attached to thesidewalls30a,30b. The resulting configuration illustrated inFIG. 4 is the KDF container blank100bthat can be shipped to the end users who will erect the KDF container blank100binto thefinal container100. All glued areas in the die-cut blank100aare at this point attached to the intended mating parts, and cured, e.g., by cooling or chemical reaction. All glued areas are on the back sides of the panels facing the viewer inFIG. 4, which is shown by “XXX” symbols in broken lines.
In an alternate embodiment, theshelf panels60 and thebellows panels25 may be attached to their respective mating parts, theback panel10 and thesidewalls30a,30bby use of fasteners rather than glue. Suitable fasteners can be, for example, one or more staples, clips, rivets, etc. In a container of sheet material comprising thermoplastic or the like, the mating parts can be welded.
FIG. 5 shows a perspective view of the KDF container blank100bready to be erected into the final container configuration. The containers are compact when stacked flat and generallycontainers100 would be shipped to the end users in the KDF container blank100bconfiguration and erected by the end user into thecontainer100. It is thus desirable that the erection be simple and sure.
Referring toFIG. 6, thetuck tabs12a,12bon theback panel10 are first folded up along thefold lines3fand then folded in the opposite direction along thefold lines4f. Referring toFIG. 7, next thesidewalls30a,30bare folded upward along the fold lines11f. As the sidewalls30a,30bare folded upward, by operation of thebellows panels25 which will fold inwardly along the fold thefold lines7f, theendwall panel20aare pushed up and raised. Because theback panel10 is now joined to bothendwall panels20a,20b, theback panel10,endwall panels20a,20band thefront panel40 first form an interim structure whose longitudinal cross-section is a parallelogram and then open into a rectilinear box-like configuration so that theback panel10 and theendwall panels20a,20bare perpendicular to each other. The parallelogram interim transient configuration is shown inFIG. 11. At the same time, because theshelf panels60 are attached to the interior surface of theback panel10, theshelf panels60 are pulled up by theback panel10. Theshelf panels60 fold upward along thefold lines6finto the interior space of the container being formed and raised in parallel formation with theendwall panels20a,20b. As mentioned above, thefold lines6fare appropriately scored or creased to preferentially fold in the desired direction allowing theshelf panels60 to fold as described. The self-erecting operation of thebellows panels25 can be helped along by folding up theendwall panel20balong thefold line5fif necessary. The depth of theshelf panels60 is generally preferred to be substantially equal to the distance between thefront panel40 and theback panel10, defined by the width of the twoendwall panels30a,30b, in the fullyerect container100. This allows the shelf structures in thecontainer100 to be in perpendicular orientation to theback panel10 and thefront panel40.
Referring toFIG. 8, the rectilinear box-like configuration is shown. Theendwall panels20a,20bare in perpendicular orientation to theback panel10 and thefront panel40. Next, thetabs26 of theendwall panel20bare folded inwardly along the fold lines10f. Then, thetabs32a,32bof the sidewalls30a,30bare folded along the fold lines11ftoward the interior of the container structure and thesidewalls30a,30bare folded into their final perpendicular orientation as illustrated inFIG. 9. Finally, thetuck tabs12a,12bare tucked into theslots34a,34bthat are provided along thefold line11fof the sidewalls30a,30b, completing the erection of thecontainer100 and fixing the container in a rectilinear shape. Theslots34a,34bmay be formed by making appropriate cuts in thefold line11fduring the die-cut operation from the stock sheet material. Referring back toFIG. 1, the bottom-most shelf is actually formed by theendwall panel20brather than by one of theshelf panels60. And one of theshelf panels60 is integrally joined to thefront face panel44aand, in the orientation of thecontainer100 shown inFIG. 1, does not function as a shelf at all. However, it should be noted that thecontainer100 may be flipped top to bottom from the orientation shown inFIG. 1 if appropriate.
The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed.