1. Field of the Invention
The present invention relates to containers in general, and more specifically to stackable containers made of paperboard. In particular, the present invention relates to a ventilated stackable container that is easy to set up, has good structural rigidity, and uses less material in its construction than conventional containers.
2. Prior Art
Containers made of paperboard, i.e., corrugated cardboard, are commonly used in the produce industry to pack, store and ship fresh produce. These containers typically have a bottom, opposite side walls, opposite end walls, and either a closed or an open or partially open top, and when filled with fresh produce are placed on a pallet for shipping and handling. A standard pallet as used in the industry has a width of 40 inches and a length of 48 inches, and the containers are sized so that a plurality of containers can be placed side-by-side on the pallet. A typical container, for example, may have exterior width and length dimensions of about 20 inches by 16 inches, whereby six containers can be placed side-by-side on the pallet. Additional containers are then stacked on top of one another to form multiple layers of containers until a predetermined number of the filled containers are supported in stacked relationship on the pallet.
The loaded pallets may then be transported to a refrigeration unit to cool and/or store the fresh produce. To insure that all of the produce is appropriately cooled, the containers are provided with ventilation openings in at least some of their side, end and/or bottom walls, and are designed so that cooling air can circulate around, through and between the containers stacked on the pallet.
To enable the containers to be stacked on top on one another in stable relationship, stacking tabs are typically provided on the top or bottom edges of at least some of the side and/or end walls, and openings or notches are provided in the opposite edge for receipt of an aligned stacking tab on an adjacent stacked container. In addition to providing a positive detent to prevent lateral shifting of the stacked containers relative to one another, the stacking tabs also serve to index the containers for proper alignment when stacked.
Further, the loaded and stacked containers are subjected to considerable forces during shipment and handling, and must have sufficient structural strength and rigidity to withstand these forces. Thus, the side and/or end walls of the containers are usually constructed with multiple thicknesses, and/or additional reinforcing structure also may be provided, and the flutes of the corrugated material are typically arranged to extend vertically.
Moreover, the containers may be constructed for hand set-up or machine set-up. If intended for hand set-up, they should be easy for the operator to manipulate, and reliably secured in their erected form. In either event, they should be economical to make and use.
U.S. Pat. Nos. 5,485,283 and 5,860,590 are exemplary of prior art stackable containers. Both of them incorporate stacking tabs and at least one wall of double thickness. Additionally, they both have additional reinforcing structure in the comers for added stacking strength. U.S. Pat. No. 5,485,283 has ventilation openings through the side, end and bottom walls, and U.S. Pat. No. 5,869,590 has the opposite end walls inwardly inclined to permit circulation of air between containers arranged in side-by-side abutting relationship. The container in U.S. Pat. No. 5,458,283 utilizes multiple reversely folded panels, and thus consumes a substantial amount of material in its construction. The container in U.S. Pat. No. 5,860,590 requires adhesive to hold it in erected position.
There is need for a paperboard container that is stackable, structurally rigid, easy to set-up, reliably remains in set-up condition, and requires a minimum amount of material in its construction.
A container that meets these needs is disclosed in applicant's copending application Ser. No. 10/287,420. That container is stackable, has structural rigidity, is easy to set-up, reliably remains in set-up condition, and requires a minimum amount of material in its construction. In the particular embodiments disclosed therein, the side walls are of double wall construction, formed by inner and outer roll-over panels, and first flap extensions on opposite ends of the inner roll-over panels are folded inwardly and lie against the inner surface of the end walls. Second flap extensions on opposite ends of the end wall panels are folded inwardly and captured between the inner and outer roll-over panels. The first flap extensions are joined to the ends of the inner roll-over panel by a pair of spaced parallel folds, forming a diagonal panel in each corner of the container. These diagonal panels provide reinforcement and lend substantial stacking strength to the container. First tabs extend upwardly from the upper edge of the outer roll-over panels in spaced relationship along its length, and second tabs on the captured second flap extensions extend upwardly through the upper edge of the side walls and lie against the first tabs to form reinforced double thickness stacking tabs on the upper edge of the side walls. The side walls incorporating the roll-over panels and stacking tabs are inwardly inclined from about 2E to about 4E, whereby when two containers are placed in side-by-side abutting relationship with one another, space is formed between the abutting walls for circulation of cooling air. Notches in the upper edges of the side and end walls, and in some embodiments openings in the field of the walls, provide ventilation for circulation of cooling air through the container and produce held therein.
The container of the invention is substantially the same as the container disclosed in applicant's above-identified copending application, except that the roll-over panels and stacking tabs are on the end walls rather than the side walls. The location and capture of the extension flaps on the ends of the roll-over panels and the side walls is also reversed from that in the prior copending application. The relocation and reversal of parts from the prior container to the arrangement of the present invention provides all the advantages of the prior arrangement, i.e., the present container is stackable, structurally rigid, easy to set-up, reliably remains in set-up condition, and requires a minimum amount of material in its construction. In the particular embodiments disclosed herein, the end walls are of double wall construction, formed by inner and outer roll-over panels, and first flap extensions on opposite ends of the inner roll-over panels are folded inwardly and lie against the inner surface of the side walls. Second flap extensions on opposite ends of the side wall panels are folded inwardly and captured between the inner and outer roll-over panels. The first flap extensions are joined to the ends of the inner roll-over panel by a pair of spaced parallel folds, forming a diagonal panel in each corner of the container. These diagonal panels provide reinforcement and lend substantial stacking strength to the container. First tabs extend upwardly from the upper edge of the outer roll-over panels in spaced relationship along their length, and second tabs on the captured second flap extensions extend upwardly through the upper edge of the end walls and lie against the first tabs to form reinforced double thickness stacking tabs on the upper edge of the end walls. The walls incorporating the roll-over panels and stacking tabs, in this case the end walls, are inwardly inclined from about 2E to about 4E, whereby when two containers are placed in end-to-end abutting relationship with one another, space is formed between the abutting walls for circulation of cooling air. Notches in the upper edges of the side and end walls, and in some embodiments openings in the field of the walls, provide ventilation for circulation of cooling air through the container and produce held therein.
Locking tabs project downwardly from the bottom edge of the inner roll-over panels and extend into notches formed at the fold joining the end walls to the bottom of the container to hold the roll-over panels in position, and thus hold the second flap extensions and their associated side wall panels in erected position. A locking tab also projects from one edge of each diagonal panel and extends into a slit formed in the adjacent side wall panel to hold the first flap extensions and associated diagonal reinforcing panels in position. No adhesive is required, and manual set-up is very easy to accomplish. A minimal amount of material is used in construction, and once set up the container reliably remains in set up condition.
A first embodiment of the invention has essentially the structure described above, and has an open top.
In a second embodiment, lid panels are foldably joined to an upper edge of each of the side wall panels, and these lid panels are folded inwardly to lie over adjacent upper edges of the end walls, completely closing the top of the container. The lid panels are held in their inwardly folded closed position by engagement of the stacking tabs in notches in the end edges of the lid panels. To accomplish this, opposite side edges of the stacking tabs are undercut, and the edges of the notches in the lid panels engage in these undercut portions. The edges of the stacking tabs above the undercut portions are inwardly tapered to facilitate downward movement of the lid panel notches over the stacking tabs.
In a third embodiment, partial lid panels are foldably joined to an upper edge of each of the side wall panels, and each of these partial lid panels are folded inwardly to lie over adjacent upper edges of the end walls, partially closing the top of the container but leaving a space between their confronting edges for circulation of air. Bendable tabs or flaps are formed on the outer end edges of the lid panels, and shaped cuts form an opening in the bendable tabs at the folding juncture between the bendable tabs and associated lid panels. The partial lid panels are held in their inwardly folded closed position by engagement of the stacking tabs in these openings and by the bendable tabs, which are folded downwardly against an outer surface of the adjacent end wall. Additionally, reversely extending locking heels are formed by the shaped cuts, and these heels extend upwardly in coplanar relationship with the bendable tabs and lie against an outer surface of the stacking tabs. The locking heels maintain the bendable tabs in downwardly folded position and frictionally engage the stacking tabs to help hold the lid panels in their inwardly folded closed positions.
Although the bendable tabs and locking heels are illustrated and described in relation to the third embodiment wherein the container has partial lid panels, these features could equally as well be applied to the second embodiment.
Containers made in accordance with the invention are very strong, having excellent structural rigidity and stacking strength, and use approximately 11% less material than conventional containers. They are simple in construction, can be easily set up by hand, and once set up reliably remain in set-up condition.
The foregoing as well as other objects and advantages of the invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
A first and preferred embodiment of the container of the invention is indicated generally at 10 in
Spaced openings or slots 28 are provided along the end edge of the bottom wall in alignment with the stacking tabs to provide receptacles for the stacking tabs of a subjacent container when the containers are stacked. The stacking tabs serve to prevent lateral shifting of the stacked containers and also index the containers into proper alignment when they are stacked with one another. The positioning of the openings 28 in the edge of the bottom wall and inside the plane of the respective side walls effectively encloses the stacking tabs when they are inserted into the openings.
The container 10 is simple in construction and uses a minimal amount of material, and yet has very good stacking strength and torsional rigidity. The end walls 13 and 14 are of triple wall thickness over most of their length, and comprise full length inner and outer roll-over panels 30 and 31, respectively, between which are sandwiched relatively long inwardly folded extension flaps 32 and 33 on opposite ends of the side walls 11 and 12, respectively.
The inner roll-over panels 30 each have extension flaps 34 and 35 on their opposite ends, traversed by pairs of relatively closely spaced parallel fold lines 36 and 37 positioned so that when the extension flaps 34 and 35 are folded inwardly alongside the inner surface of the respective side walls 11 and 12, the portion of the extension flaps between the parallel fold lines define the diagonal corner panels 16, 17, 18 and 19, which extend at about a 45° angle relative to the adjacent side and end walls.
A cut 38 is made in each extension flap 34 and 35 at the fold line 37, defining a tab 39 that projects from the fold line coplanar with the associated corner panel 16, 17, 18 or 19 when the extension flaps are folded into their operative set-up position, and these tabs 39 project into slots 40 formed in the adjacent side walls to hold the extension flaps 34 and 35 in their set-up positions alongside the inner surface of the respective side walls.
The roll-over panels are held in their inwardly folded set-up positions by a plurality of tabs 41 projecting from the bottom edge of the inner roll-over panel engaged in slots 42 formed along the end edges of the bottom wall 15. As seen best in
Cuts 45 are also formed in the bottom edge of inner roll-over panels 30 for registry with the stacking tab receiving slots 28 to prevent interference between the bottom edge of the inner roll-over panel and the stacking tabs when the stacking tabs are inserted into slots 28.
The double ply stacking tabs 20-23 are formed by first tabs 46 projecting upwardly from the upper edge of the extension flaps 32 and 33 and second tabs 47 that are cut from the inner roll-over panel, as described more fully below, and project upwardly from the fold 48 between the inner and outer roll-over panels. The fold 48 is formed by closely spaced parallel fold lines 49 and 50 that define between them roll-over bands 51 that wrap over the upper edge of the side walls and present a smooth, finished appearance to the edges. The tabs 47 are formed by cuts 52 and 53 extending from the upper edge of outer roll-over panel 31 through and beyond the fold lines 49 and 50 and into the inner roll-over panel, where the cuts terminate in a slot 54 located so that the tab 46 can pass through the slot when the roll-over panels are folded into their operative set-up position. When the roll-over panels are in their operative set-up positions, the tabs 47 project upwardly as a continuation of the outer roll-over panel and coplanar therewith, and the tabs 46 on the extension flaps 32 and 33 lie against the inner surface of the tabs 47 and reinforce them.
With particular reference to
Manual set-up of the container 10 is easily accomplished. The extension flaps 32 and 33 are folded inwardly, or upwardly with reference to the blank in
As seen best in
The simple arrangement of panels, flaps and locking tabs, as described, requires less material than prior art containers of comparable structure and function, and the container thus formed is sturdy and reliably remains in erected position.
A second embodiment of the invention is indicated generally at 60 in
The container 60 differs from that previously described primarily in that it has lid panels 61 and 62 that are folded inwardly over the top of the container from opposite sides to completely cover the top of the container. Further, ventilation openings 63 span the fold joining the lid panels to the side walls, and these ventilation openings extend into the lid panels and into the upper edges of the side walls.
It will be noted that the stacking tabs 20′-23′ have undercut notches 64 formed in their side edges, and these notches cooperate with cut-outs 65 in the end edges of the inwardly folded lid panels to hold the lid panels in closed position. Additionally, the upper outer edges of the tabs are inwardly tapered at 66. These features are seen best in
In all other respects, the container 60 is constructed and functions essentially the same as the previously described embodiment.
A third embodiment of the invention is indicated generally at 70 in
While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications may be made to the invention without departing from the spirit and intent of the invention as defined by the scope of the appended claims.
This application is a continuation-in-part of application Ser. No. 10/287,420, filed Nov. 4, 2002, which claims the benefit of US provisional application Ser. No. 60/336,486, filed Nov. 2, 2001.
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Number | Date | Country |
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444 004 | Aug 1991 | EP |
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Number | Date | Country | |
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20050145687 A1 | Jul 2005 | US |
Number | Date | Country | |
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60336486 | Nov 2001 | US |
Number | Date | Country | |
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Parent | 10287420 | Nov 2002 | US |
Child | 10957412 | US |