Composite shipping container with separable top and bottom structures

Abstract: A shipping container (10) having an inner tank (12), a housing (16) and a pallet (14). The tank (12) is made of poly material and is positioned and supported within the housing (16) on the pallet (14). The housing (16) includes upright side walls (32) which maintain the tank side walls in an upright position and further includes a top structure (28) and bottom structure (30). The bottom structure (30) is attached to the pallet (14) and assists the pallet in supporting the weight of the tank (12). Both the top and bottom structures (28,30) incorporate features which allow them to self engage the upper and lower periphery ends of the side walls (32) upon relative telescoping movement between the top and bottom structures (28,30) and the side walls (32). This engagement is releasable and generally allows the housing to be quickly and securely snapped together.

Description: BACKGROUND AND SUMMARY OF THE INVENTION The invention relates to bulk liquid shipping containers. More particularly, the invention a composite shipping container which includes an outer container that encloses a synthetic resin inner tank. The top and bottom structures of the outer container are provided with an attaching mechanism that connect to the side walls of the outer container. An example of a composite shipping container known within the industry is disclosed in U.S. Patent No. 4,793,519, which is commonly assigned to the Assignee of the present application. In general, these composite shipping containers comprise an outer container of sheet metal or corrugated paper and enclose a synthetic resin or poly tank. The inner tank is filled with a liquid or another bulk material and is maintained in its upright position by the outer container. Both the outer container and inner tank may be supported on a pallet member having a support surface specifically for that purpose. However, these prior composite shipping containers have exhibited various limitations. One limitation is that the containers are difficult or impossible to disassemble once the liquid contained therein has been discharged. Following from this it can be seen that the prior containers do not readily lend themselves to reuse (the inner tank must be cleaned) or recycling (non-compatible materials must be separated). Another limitation is that if a portion of the container became damaged, the entire container was discarded. With the limitations of the prior art in mind, it is an object of the present invention to provide a composite shipping container which is readily assembled and disassembled to facilitate the recycling and/or reuse of its major components. It is another object of the invention to provide a composite shipping container wherein the top and/or bottom structures of the outer container are readily assembled with the side walls of the outer container. It is a further object of this invention to provide a composite shipping container having a modular assembly in which the major subassemblies can be easily replaced if damaged. It is an additional object of the invention to provide a composite shipping container in which the container's subassemblies allow for other containers to be easily remanufactured for compatibility therewith and subsequent reuse. EP-A-0 239 709 discloses a shipping container in accordance with the prior art portion of claim 1. This prior shipping container proposes a base which is permanently fixed to the walls of the outer container and with a lid which is securable thereto, to enclose the poly-container, by bolts or equivalent means. Accordingly, this prior construction has the drawbacks considered above in that it cannot be readily demounted and that it does not have a modular assembly in which major sub-assemblies can be easily replaced if damaged. The present invention, as defined in claim 1, provides for securing means which are self-engaging in that they engage responsive to assembly of the shipping container. Furthermore, these securing means are releasable, permitting the container to be separated into the top, the side walls and the base structure in a manner which is not possible with the prior construction of EP-A-0 239 709. Thus, in achieving the abovementioned objects, a composite shipping container is provided by the present invention wherein the top and bottom structures of the outer container are provided with engaging mechanism that enable them releasably securely to attach to the body or side walls of the outer container to enclose and support the inner tank, this securement being responsive to the telescoping assembly of the top and bottom to the side walls, the bottom structure of the member of the outer container is secured to a pallet which may include openings for fork lift tines allowing the shipping container to be easily manipulated and handled. The side walls of the outer container engage the bottom member along their lower periphery. Once engaged, the side walls are retentively secured by the bottom member and permit the inner tank to be positioned in the outer container and supported thereby. The top structure or wall of the outer container is lowered onto the upper periphery of the outer container side walls. In a manner similar to the bottom member, the top wall engages the upper periphery of the side walls and is releasably retained thereon. The inner tank may now be filled with a bulk liquid material and shipped to the consumer. Upon the inner tank being emptied, the composite shipping container of the present invention is readily disassembled. The top wall and bottom member may be disengaged from the side walls by merely providing a force which is sufficient to overcome the retaining force. With the top wall removed the inner tank may be removed from the outer container and discarded, recycled or cleaned for reuse. If one of the subassemblies has become damaged, for example the top wall, it can be readily replaced. After disassembly, the outer container can be sent back to the original supplier in a space conserving size for subsequent reuse. Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a composite shipping container embodying the principles of the present invention; Figure 2 is an exploded front elevational view of the shipping container seen in Figure 1; Figure 3 is a sectional view of a portion of the shipping container illustrating one embodiment of the top wall engaging a side wall as provided for by the present invention; Figure 4 is a sectional view of a portion of the shipping container showing one embodiment of the bottom member engaging a side wall as provided for by the present invention; Figure 5 is a sectional view of a portion of the shipping container of the present invention showing a second embodiment of the top wall engaging a side wall of the outer container; and Figure 6 is a sectional view of a portion of the present invention showing a second embodiment of a side wall being engaged to the bottom member and pallet. DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring now to Figure 1, the composite shipping container of the present invention is generally designated at 10 and includes an inner tank 12 which is supported on a pallet 14 and enclosed within an outer container or housing 16. The inner tank 12 is generally of a unitary construction and is blow molded from a synthetic resin so as to have substantially thin side walls. As such, the tank's side walls are incapable of supporting the tank 12 in an upright position. Tanks 12 of this type are well known within the industry and are typically made from high density polyethylene (HDPE) and referred to as poly tanks. The tank 12 also typically includes a fill opening or port 18 located in the top wall 20 and a discharge opening or port 22 located in one of the side walls adjacent to the bottom wall of the tank 12 or actually in the bottom wall itself. As mentioned above, the tank 12 is supported on an uppermost support surface 26 (Fig. 2) of pallet 14. The pallet 14 may be a wooden pallet or a metal pallet and may include openings 24 which will allow for the insertion of fork lift tines to manipulate the shipping container 10. In the preferred embodiment, the pallet 14 is made of metal and incorporates a truss construction. The housing 16 rests upon the upper surface 26 of the pallet 14 and generally includes a top structure or wall 28, a bottom member or structure 30 and substantially upright side walls 32. The bottom member 30 is attached to the pallet 14. While the pallet 14 may be constructed in numerous ways, in the preferred embodiment, the bottom member 30 of the housing 16 is welded to the pallet 14 so as to integrally form a part of the support surface 26. If a wooden pallet 14 is used, the bottom member 30 may be nailed or screwed thereonto. As more fully described below, the side walls 32 are attached at their lower periphery to the bottom member 30 along the perimeter of the support surface 26 in a releasable and generally, self-engaging manner. The side walls 32 can be constructed from fiber board, galvanized sheet metal, wire or tubular mesh, and other similar materials and can have any desired finish. In the preferred embodiment, the side walls 32 are constructed of a flexible wire mesh which is flexible enough to allow the wire mesh to be wrapped around the side walls of the inner tank 12. As seen in Figures 1 and 2, the opposing ends of the side wall 32 are joined and secured together by a splice plate 34. While the splice plate 34 may be positioned along any of the side walls 32, in the present invention it is positioned so as to have a lower portion defining an access opening 36 corresponding to the tank's discharge port 22. The size of the splice plate 34 may be varied to allow for markings, such as the contents or safety warnings, to be displayed on the container 10. In a manner similar to the bottom member 30, the top wall 28 is secured to the upper periphery of the side walls 32. In the preferred embodiment, the top wall 28 utilizes a strut 40 and circumferential member 38 construction. Alternatively, the top wall 28 can have a plate or solid wall construction, so long as an opening is provided for the fill port 18 of the inner tank 12. A major feature of this new composite shipping container 10 is the manner in which the top wall 28 and bottom member 30 are attached to the side walls 32. In joining the top wall 28 and bottom members 30 to the side walls 32, a generally self-engaging or snap-together assembly is utilized. Two embodiments of the assembly are illustrated in Figures 3-6. The assembly is referred to as being generally self-engaging because the attachment is operable upon relative telescopic movement between either the side walls 32 and the top wall 28 or bottom member 30. The first of the two embodiments incorporates biased tabs 42, while the second employs a frictional engagement, the structure of which is hereinafter referred to as a "T-angle" 44. As seen in the embodiment of Figures 3 and 4, the bottom member 30 and the circumferential member 38 of the top wall 28 are constructed with an angled perimeter. As such, each includes a generally vertical or upright flange 46 along its perimeter. The biased tabs 42 are positioned along the upright flanges 46 of the top wall 28 and bottom member 30 and are integrally formed as cut out sections. This provides the invention with a simplified manufacturing techniques. The tabs 42 are biased inward from the flanges 46, toward the inner tank's 12 position, and extend generally upward in the top member 28 and downward in the bottom member 30. The bias tabs 42 are specifically designed to be used with the wire mesh side walls 32 illustrated in Figure 1, however other side wall constructions could also be used. Being constructed of wire mesh, the side walls 32 exhibit a criss-crossed or latice network of lateral or cross wires 48 and upright wires 50. When engaging the top wall 28 and bottom member 30 with the side walls 32, the upper and lowermost cross wires 48 will correspondingly deflect the tabs 42 against their biasing until the tabs 42 "snap over" the cross wires 48 locking the side walls 32 into engagement. As readily seen in the drawings, the tabs 42 form a positive interference engagement with a surface of the cross wires 48 and prevent withdrawal or disengagement thereof. To disengage the side walls 32 from the top wall 28 and bottom member 30, the tabs 42 need only be deflected against their biasing an amount which will allow the cross wires 48 to pass thereby. In the alternative embodiment of Figures 5 and 6, the T-angle 44 is shown as having the generally upright flange 46 along its perimeter. As the name implies, the T-angle 44 is generally T-shaped in cross-section with the flange 46 forming the cross-bar as seen in Figures 5 and 6. A receiving slot 52 is defined by one end of the flange 46 being bent back upon itself to form a generally U-shaped channel at one extreme of the cross-bar. The dimensions of the receiving channel 52 are such that a side wall 32, illustrated as being sheet metal in Figures 5 and 6, can be inserted and frictionally retained therein. When it is desirable to stack the composite shipping containers 10, the U-shaped channel in the "T" angle 44, extending upward from the top wall 28, operates as a containing flange encircling the metal pallet 14 positioned therein. If a container 10 having a wooden pallet is to be stacked, the U-shaped channel operates as a supporting surface. In either situation, the "T" angle 44 assists in providing stability to the stacked arraignment. While the second embodiment is generally illustrated as a T-shape, other structural shapes may also be utilized as well as the side walls 32 may be constructed from other materials. Furthermore, the two embodiments could be combined to provide for an extra measure of retaining force on the side walls 32. As previously mentioned, the bottom member 30 of the housing 16 may be directly incorporated into the pallet 14 or may be separately attached thereto. For example, if the pallet 14 is constructed of wood and has a wooden support surface 26, the bottom member 30 may form the support surface 26 or may merely be a circumferential member 38, similar to that of the top wall 28, attached along the perimeter of the support surface 26. In the preferred embodiment the pallet 14 is metal and the bottom member 30 is welded thereto to form an integral part of the pallet 14, including as part thereof, the support surface 26. As apparent from the construction of the preferred embodiments, various aspects of the invention can be utilized to re-manufacture used shipping containers. For example, the "fixed" top of an old shipping container may be cut off allowing the container to be retro-fitted with either the T-angle 44 or bias tab 42 top wall 28 disclosed by this invention. Similar retro-fitting can be done with the bottom member 30 or pallet 14. Additionally, all portions or subassemblies of present composite shipping container 10 can readily be replaced if damaged during use thereby eliminating the need to discard the entire shipping container.

Claims: A shipping container (10) having a removable inner tank (12) for transporting bulk liquid materials, a base structure (14) having an upper support surface (26) for supporting the tank (12), a housing (16) including upright side walls (32) having upper and lower peripheries, said side walls (32) being supported on said support surface (26) and substantially encircling the tank (12) therein, said housing (16) also including a top (28) in engagement with said upper periphery of said side walls (32) to enclose the tank (12) within said housing (16), said shipping container being characterised in that a self-engaging securing means (42,44) is provided for releasably securing said top (28) to said upper periphery of said side walls (32) and for releasably securing said base structure (14) to said lower periphery of said side walls (32) in response to relatively telescoping movement therebetween, said securing means (42,44) thereby allowing said container (10) to be separated into said top (28), said side walls (32) and said base structure (14) upon the emptying and removal of the tank (12). A shipping container (10) as set forth in claim 1, wherein said support surface (26) includes a plurality of generally upright peripheral flanges (46) substantially in registry with said lower periphery of said side walls (32) and wherein said top (28) includes generally downward peripheral flanges (36) substantially in registry with said upper periphery of said side walls (32). A shipping container (10) as set forth in claim 2, wherein said securing means (42,44) includes a plurality of resilient tabs (42) projecting from said support surfaces (26) and said top (28), said tabs (42) interferingly engaging said upper and lower periphery to maintain said side walls (32) in engagement with said top (28) and said base structure (14). A shipping container (10) as set forth in claim 3, wherein said tabs (42) project generally angularly inward and downward from said upright peripheral flanges (46) and angularly inward and upward from said downward peripheral flanges (46). A shipping container (10) as set forth in claim 4, wherein said tabs (42) are integrally formed with said flanges (46). A shipping container (10) as set forth in claim 1, wherein said securing means (42,44) includes portions (46) defining at least one receiving slot (52) adjacent said top (28) and at least one receiving slot (52) adjacent said support surface (26) telescopingly to receive said upper and lower peripheries and frictionally to retain said peripheries therein. A shipping container (10) as set forth in claim 6, wherein said portions defining said slots (52) form peripheral flanges (46) generally circumscribing said top (28) and said support surface (26). A shipping container (10) as set forth in any preceding claim, wherein said securing means (42,44) is integrally formed in said top (28) and said base structure (14). A shipping container (10) as set forth in any one of claims 1 to 5, wherein said securing means (42,44) utilises a snap-fit engagement between said top (28) and said base structure (14) and said upper and lower peripheries of said side walls (32) to interferingly prevent disengagement of said top (28) and said base structure (14) and said side walls (32). A shipping container (10) as set forth in claim 1, wherein said securing means (42,44) includes a projecting tab (42) and portions defining an opening having an engagement surface (48) for coating with said tab (42) to prevent disengagement of said top (28) and said base structure (14) from said peripheries of said side walls (32). A shipping container (10) as set forth in claim 10, wherein said tabs (42) are integrally formed on said top (28) and said base structure (14) and deflectably project therefrom. A shipping container (10) as set forth in any one of claims 1, 6 and 7, wherein said securing means (42,44) frictionally retains said top (28) and said base structure (14) in engagement with said upper and lower periphery of said side walls (32). A shipping container (10) as set forth in claim 12, wherein said securing means (42,44) includes portions defining receiving slots (52) in said top (28) and said base structure (14), said receiving slots (52) being of a size generally corresponding to said side walls (32) thereby to receive and frictionally retain said side walls (32) therein. A shipping container (10) as set forth in claim 13, wherein said receiving slots (52) are defined in the periphery of said top (28) and said base structure (14) and are formed by a portion being bent generally perpendicular to said top (28) and said base structure (14) and thereafter being bent back upon itself to define said slots (52), said periphery thereby having a generally T-shaped cross-sectional shape (44). A shipping container (10) as set forth in any preceding claim, wherein said side walls (32) are constructed substantially continuous therearound and employ fastening means (34) for securing said side walls (32) to form said substantially continuous construction. A shipping container (10) as set forth in any preceding claim, wherein said side walls (32) are formed of wire mesh and include generally criss-crossed members. A shipping container (10) as set forth in any preceding claim, wherein said base structure (14) includes a pallet formed of tubular metal trusses welded thereto. A shipping container (10) as set forth in any preceding claim, wherein the inner tank (12) is of poly-material with the tank (12) having a top wall (20) integrally connected with substantially upright side walls which are integrally connected with a bottom wall, the tank having a fill port (18) positioned in the top wall (20) and a discharge port (22) located adjacent to the bottom wall, the housing (16) side walls being in side-by-side contact with the inner tank (12) side walls. A shipping container (10) as set forth in claim 18, wherein the inner tank top (20) and side walls are sufficiently thin to be incapable of supporting themselves. A shipping container (10) as set forth in claim 18 or 19, wherein portions of one of the housing side walls (32) provide an access opening (36) corresponding with the discharge port (22) and the housing top (20) has portions defining an access area permitting access to the fill port (18).

Inventors: NICHOLS DWIGHT ELLIS, NICHOLS, DWIGHT ELLIS
Applicants: HOOVER GROUP INC
Application year: 1991
Main classification: B65D77
IPC codes: B65D77, B65D19, B65D88