Patent Publication Number: US-6220473-B1

Title: Collapsible vacuum panel container

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority from Provisional Application Serial No. 60/143,696, filed Jul. 14, 1999, entitled SOFT-SHELL CONTAINER. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to thermally insulated containers, and, more particularly, to insulated containers which are collapsible for smaller storage or shipping for reuse. A collapsible insulated container breaks down to allow it to be stored or boxed and shipped, by having some or all of the edges of the container be separable. If only some edges are separable, the remaining edges are flexible, allowing for folding of the side walls. 
     Collapsible insulated containers have a number of advantages over fixed wall thermally insulated containers. The walls of the collapsible containers can be folded such as when not in use or broken down to fit into a small area or shipping box. Collapsible containers are generally light weight. Though the use of collapsible containers may involve vigorous wear and tear, collapsible containers can be made durable and attractive for multiple uses over an extended period of time. In industries where product must be kept cold and shipped overnight or over a short period of time, such collapsible containers are often preferable to containers with fixed walls, because they can be collapsed during return shipment and non-use. 
     While collapsible containers have many advantages, the very nature of the container leads to a number of problems as compared to fixed wall containers. The collapsible container must have either flexible side walls or separable side walls to allow for folding of the container. Separable sidewalls can lead to thermal problems including the escape of heat or cold from the container through gaps between the sidewalls, the base and/or the cover. In addition, the relative fit of the separable edges of the container is determined for each use upon set-up, precise dimensions may vary and thermal problems may vary from use to use. 
     The design of the collapsible container needs to be efficient and inexpensive, from the stand point of both the cost of the materials and the amount of the materials used. The collapsible container should also be easy to manufacture. In addition, depending on the type of thermal insulation used, the insulation of the collapsible container may be damaged or punctured during use. And finally, the container must be easy to assemble such that potential thermal problems are minimized during the set-up process. 
     BRIEF SUMMARY OF THE INVENTION 
     A soft-sided, collapsible insulative container having a base, peripheral sidewalls extending from the base, and a lid. The sidewalls fold upward from the base at a fold hinge and releasably attach at their vertical edges to form an enclosure. The lid fits the top of the enclosure. Each of the sidewalls, the base and the lid are formed of a pocket for receiving block insulation. The pocket is lined with compressible insulation. Each pocket may be sealed to secure the block insulation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a collapsible vacuum panel container in the set-up and assembled position according to the present invention. 
     FIG. 2 is a perspective view of the container of FIG. 1 showing unzipping. 
     FIG. 3 is a perspective view of the container of FIG. 1 in an open position. 
     FIG. 4 is a perspective view of the container of FIG. 1 in a partially broken down position. 
     FIG. 5 is a perspective view of the container of FIG. 1 in a broken down position. 
     FIG. 6 is a perspective view of the container of FIG. 1 in a broken down and partially folded position. 
     FIG. 7 is a perspective view of the container of FIG. 1 in a broken down and completely folded position. 
     FIG. 8 is a cross-sectional view of a vertical cut through a side and base of the container of FIG.  1 . 
     FIG. 9 is an cross-sectional view of a wall of the container of FIG.  1 . 
     FIG. 10 is a perspective view of an alternative embodiment of the wall of the container of FIG. 1 that is fully separable from the container. 
     While the above-identified illustrations set forth preferred embodiments, other embodiments of the present invention are also contemplated, some of which are noted in the discussion. In all cases, this disclosure presents the illustrated embodiments of the present invention by way of representation and not limitation. Numerous other minor modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention. 
    
    
     DETAILED DESCRIPTION 
     A container  10  of the present invention generally includes a base  12 , sidewalls  14 , and a lid  16 . Each of the sidewalls  14  are flexibly attached to the base  12  by a flexible hinge  18  (shown in FIG.  5 ). The sidewalls  14  fold upward at the flexible hinge  18  and attach at their vertical edges  20  to form an enclosure  22  with a top opening  24  (shown in FIG.  3 ). The flexible hinge  18  is permanently attached to the base  12 , preventing the sidewalls  14  from becoming completely separated from the base  12 . 
     As shown in FIG. 1, the container  10  can be commonly positioned so the base  12  is at the bottom  26  of the container  10 , and the sidewalls  14  extend generally upward. However, the container  10  can be used in other orientations as well, and the use of the terms “base” and “sidewall” is not intended to limit the orientation of use. 
     In the preferred embodiment, each of the base  12  and the sidewalls  14  are appropriately sized rectangles. In the assembled position, the sidewalls  14  are at right angles to the base  12  and to each other, so the container  10  has the shape of a box with a top opening  24 . 
     The lid  16  is similarly rectangular and sized to fit the top opening  24  such that in the closed position the lid  16  covers the top opening  24 . The lid  16  is also flexibly attached to the base  12  by a “flexible casing” or “binding casing”  28 . The flexible casing  28  is integrally formed with the outside surface  30  of the lid  16  and the bottom surface  32  of the base  12 . The flexible casing  28  extends beyond the edges  34  of the lid  16  and the base  12 , extending down from the lid  16  and up from the base  12  to releasably attach at the midpoint  36  between the lid  16  and the base  12  along the sidewalls  14 . The flexible casing  28  is formed and sized to fit tightly around the set-up container  10 . In the set-up position, the flexible casing  28  will place a uniform pressure on the lid  16 , base  12  and sidewalls  14 . In the preferred embodiment, the flexible casing  28  covers the-entire surface area of the container  10 , and the attachment is made by a zipper  38  having two zipper handles  40 , allowing the container  10  to be locked with a padlock  44  or other means when in a set-up and zipped position. 
     Other means could be used to releasably attach the flexible casing  28  at the midpoint  36  of the container  10 , including straps, snaps, hooks, or any other releasable means. In the preferred embodiment, a zipper  38  is used. Additional the zipper or other releasable connector need not be located at the midpoint  36 , but rather may releasably connect the flexible casing  28  to the rest of the container  10  at the base  12 , the lid  16 , or at any height along the sidewalls  14 . The zipper  38  pulls the two ends  46  of the flexible casing  28  together as it is zipped closed, placing and maintaining a uniform pressure on the base  12 , sidewalls  14  and lid  16  of the container  10 . The pressure provided by the flexible casing  28  provides several thermal benefits that will be discussed in detail in the following paragraphs. 
     The flexible casing  28  is formed of a durable, flexible, lightweight fabric. The flexible casing  28  must be durable to a withstand impacts, to protect against punctures or tearing, and to allow for multiple uses and reuses of the container  10 . In addition, the flexible casing  28  must be able to withstand exposure to water, temperature changes, pressure changes, and numerous other damaging elements. The flexible casing  28  could be made from any lightweight, flexible and durable material, including a heavy nylon such as 400 weight or greater. In the preferred embodiment, the flexible casing  28  and the exposed exterior and interior faces of the sidewalls  14  are formed of the same material, CORDURA, such as that manufactured by DuPont. 
     Handles  74  may be attached to the outside of the container  10  to facilitate handling and transport. In the preferred embodiment, handles  74  are formed by two fabric straps, which extend in opposite directions from the bottom  26  of the base  12  around flexible casing  28 . The handles  74  can be formed of any durable material. In the preferred embodiment, the handles  74  are formed of a heavy weight nylon approximately 1.5 inches wide. The handles  74  can be wrapped around of the sides of the container  10  and can meet over the top of the flexible casing  28  to help support the thermal container  10  during transport. In addition, velcro or other attaching means may be used to create a handle that holds the ends of the two loops together when in an closed position. 
     FIG. 2 illustrates an embodiment of the container  10  having a zipper  38  for attaching the flexible casing  28  at the midpoint  36 . FIG. 2 illustrates the direction for unzipping the flexible casing  28 , allowing the container  10  to be opened. With two zipper handles  40 , the container  10  unzips in opposite directions. The flexible casing  28  connects the lid  16  to the base  12  on one side of the container  10 . Unzipping the zipper  38  releases the pressure placed on the lid  16 , the base  12  and the sidewalls  14  by the flexible casing  28  and allows the flexible casing  28  to be unwrapped from around the sidewalls  14 . 
     In the preferred embodiment, the flexible casing  28  defines a narrow connection portion  42  best shown in FIGS. 2 and 6 that connects the base  12  to the lid  16 . The flexible narrow connection portion  42  prevents the lid  16  from becoming separated from the container  10  in storage or during shipping. The narrow connection portion  42  prevents the two zipper handles  40  from meeting, and prevents the normal force of the sidewalls  14  and lid  16  from causing the zipper  38  to unzip. The flexible narrow connection portion  42  need not extend for the full width of a sidewall  14 . In the preferred embodiment, the flexible narrow connection portion  42  extends less than the full width of the sidewall  14  to facilitate a tighter fit when the container  10  is fully closed. The lid  16  is otherwise separate from the sidewalls  14 . Workers skilled in the art will appreciate that many alternative shapes can be selected for any of the base  12 , the sidewalls  14 , and the lid  16  to provide a closeable container  10 . As shown in FIG. 2, a lock  44  may be used when the container  10  is fully closed to prevent undesired unzipping or tampering. 
     FIG. 3 illustrates the container  10  after the flexible casing  28  has been unzipped and unwrapped from the sidewalls  14 . The lid  16  folds back on the narrow connection portion  42 , exposing the sidewalls  14  with an opening  24 . As shown in FIGS. 3 and 4, two opposing sidewalls  14   a,    14   b  have flexible attachment flaps  48 , which extend from the two opposing sidewalls  14   a,    14   b.  The attachment flaps  48  extend beyond the width of sidewalls  14   a,    14   b  along their vertical edges  20 . The flaps  48  may be made out of any flexible material, including rubber, fabric, or even thin metal. In the preferred embodiment, the flaps  48  are made out of the same material as the sidewalls  14  and the flexible casing  28 . 
     When the container  10  is in the set-up position of FIGS. 1-3, the flaps  48  extend around the vertical edges  20  to releasably attach to the adjacent sidewalls  14   c,    14   d.  The flaps  48  hold the sidewalls  14  together in the set-up position, helping the container  10  to maintain its shape during set-up. The flaps  48  may be attached to the outside  30  of the opposing sidewalls  14   a,    14   b  by any means, including glue or stitching. The flaps  48  may be releasably attached to the adjacent sidewalls  14  by any means, including a hook and eye, velcro or a snap. In the preferred embodiment, the flaps  48  are fixedly attached to the outside of two opposing sidewalls  14   a,    14   b,  and velcro is used to releasably attach the flaps  48  to the outside of the adjacent sidewalls  14   c,    14   d.  As shown in FIGS. 3 and 4, the flaps  48  can be detached to collapse the container  10 . The collapsed container  10  can then be folded into a smaller volume for return shipping as shown in FIGS. 5,  6  and  7 . 
     In addition to helping the container  10  maintain its shape during set-up, the attachment flaps  48  also push the sidewalls  14  tightly together. This pressure increases the strength of the filly closed container  10 , and improves thermal properties which will be discussed in greater detail in the following paragraphs. 
     In the preferred embodiment, the attachment flaps  48  are formed of the same material as the sidewalls  14 , lid  16  and base  12 . The attachment flaps  48  extend less than the full height of the sidewalls  14  to facilitate folding of the sidewalls  14  when the container  10  is broken down. The velcro attachment  50  is easy to assemble, and it allows the sidewalls  14  to be attached tightly during the set up process. As the velcro attachments  50  are released, the attachment flaps  48  fold back and the sidewalls  14  are no longer held in an upright position, as shown in FIG.  4 . 
     FIG. 5 illustrates the container  10  in a fully flattened or collapsed position. As can be seen in FIG. 5, each of the sidewalls  14  are permanently attached to the base  12  solely by a flexible hinge  18 . The flexible hinge  18  may be formed of any lightweight, flexible material. In the preferred embodiment, the flexible hinges  18  are formed of the same material as the sidewalls  14  and the base  12 , namely a heavy nylon or CORDURA. By manufacturing the flexible hinges  18  from the same material as the sidewalls  14  and the base  12 , manufacturing costs are reduced, and thermal loss caused by variations in thermal expansion and contraction is reduced. 
     While the flexible hinges  18  may be attached to the base  12  by any means, in the preferred embodiment, the flexible hinges  18  are attached by stitching. In addition to preventing separation from the base  12 , the flexible hinges  18  also provide a snug fit during set-up. In the preferred embodiment, the flexible hinges  18  is cut to be approximately 1 and ½ times the depth of the base  12 , and is attached to the bottom  32  of the base  12 . When the sidewalls  14  are raised and pulled upward, the flexible hinges  18  can extend to leave about ⅜ inches of space or more between the base  12  and the bottom edge  52  of the sidewall  14 . The flexible hinges  18  should be slightly larger than the depth of the base  12  to allow the sidewalls  14  to fold up when the container  10  is broken down or collapsed. 
     In the preferred embodiment, the flexible hinges  18  extend less than the full width of the sidewalls  14  to facilitate folding. While the flexible hinges  18  could extend for the full width of the sidewalls  14  and the container  10  would still collapse and fold, slightly smaller flexible hinges  18  allows the container  10  to be folded into a smaller area. 
     The flexible hinges  18  and the attachment flaps  48  do not cover the edges completely. In addition, the flexible hinges  18  leave a space between the base  12  and the sidewalls  14  when the container  10  is set-up. This means there is a thermally disconnected junction defined at each corner  54  and at the edges  24 , 34 , 52 . The disconnected junctions  24 , 34 , 52 , 54  can be a major source of thermal loss. In collapsible container, thermal loss at the disconnected junctions  24 , 34 , 52 , 54  may be exacerbated by imprecise attachment of the sidewalls  14  to each other and the base, or the lid  16  relative to the top opening  24  during the set-up process. 
     FIG. 5 illustrates the container  10  in the fully collapsed position. The collapsed container  10  may be folded further, as shown in FIGS. 6 and 7. The resulting collapsed and folded container  10  (shown in FIG. 7) will occupy less space than the assembled container  10  (FIGS.  1  and  2 ). For example, a collapsible container  10  that is 18 inches long, 18 inches wide, and 12 inches high can be collapsed and folded into a volume that is 18 inches long by 18 inches wide by 6 inches high. The size of the base  12  and lid  16  determine the length and width of the collapsed and folded container  10 . The thickness of the sidewalls  14 , base  12 , and lid  16  together determine the height of the collapsed and folded container  10 . In the preferred embodiment, the collapsed container  10  can be folded to fit inside a return volume which is 50% or less of the set-up volume, so that it can be returned for reuse. The flexible hinges  18  allow the sidewalls  14  to fold flat as shown to create a small object for shipping. 
     FIG. 8 illustrates the junction between a sidewall  14  and the base  12  in the closed position. When the container  10  is in a closed position, the sidewalls  14  fold upward onto the base  12  to form the enclosure with a top opening  24 . The bottom edge  52  of the sidewalls  14  rest on the upper surface  56  of the base  12 , but the flexible hinges  18  do not pull the sidewalls  14  and the base  12  together. When the lid  16  is placed on top of the top opening  24 , the weight of the lid  16  and the sidewalls  14  places slight pressure on the compressible insulation layer. 
     Each sidewall  14 , the base  12  and the lid  16  are generally formed of several layers, including an inside wall  58 , a continuous lining of compressible insulation  60 , block insulation  62 , and an outer wall  64 . The benefits of the continuous lining of compressible insulation  60  together with block insulation  62  between inside wall  58  and outer wall  64  are further described in application number 09/347,663 filed Jul. 6, 1999, which is hereby incorporated by reference. As used herein, the term “block insulation” is intended to include any insulation product which is substantially rigid, uncompressible and shape retaining in conditions of use. The inside wall  58  and the outer wall  64  are attached on three edges to form a pocket  66  with an opening  68 . The pocket  66  is sized to fit block insulation  62 . 
     The outer wall  64  may extend beyond the edge  72  of the block insulation  64 , forming a wall flap  70  which may be folded over the opening  68  to enclose the block insulation  62  as shown in FIG.  9 . The outer wall  64  is releasably attached to the inner wall  58  to form a closed pocket  66 . In the preferred embodiment, velcro  50  is used to form the attachment. The releasable attachment  50  allows for replacement of the block insulation  62  if the block insulation  62  becomes damaged or cracked during use. 
     While in another embodiment, the wall flap  70  could extend from the inside wall  58  and attach to the outer wall  64 , the resulting structure would be less asthetically pleasing. Further, by maintaining the attachment of the flap  70  on the inside of the container, the flap junction poses less of a threat from the ambient environment. The junction is maintained inside, so that even if it is not fastened completely, it will not allow outside air into the sidewall. 
     Further, the lid  16  and the base  12  have similar pockets. Both have a wall flap  70  which closes on the inside of the enclosure  22 . Base  12  has a wall flap  70  (not shown), which the flap  70  closes on the inside of the enclosure  22 , behind a hinge  18 . 
     The compressible insulation  60  serves as a continuous lining for the inside of the pocket  66 . Each sidewall, the rear wall, the front wall, the base  12  and the lid  16  have such a pocket  66 . Generally, the outer wall  64  extends further than the inner wall  58  to form a flap  70  that folds over the pocket opening  66  and releasably attaches to the inner wall  58 . In an another embodiment, the inside wall  58  and the outside wall  64  may both extend beyond the edge  72  of the block insulation  62 , overlapping to releasably close the pocket  66 . Alternately, the flap  70  could be permanently sealed. In the preferred embodiment, the attachment is releasable to permit changing of the block insulation  64 . The flap  70  is also lined with compressible insulation  60 . 
     Each piece of block insulation  64  slides into its respective pocket  66 . When each pocket  66  is sealed closed around its block insulation  62 , the block insulation  62  is surrounded on all six sides by compressible insulation  60 . The compressible insulation  60  reduces convection currents along the edges  72  and through the block insulation  62 . When the container  10  is fully assembled, the compressible insulation  60  is compressed between the block insulation  62  and the inside and outer walls  58 , 64 , improving the thermal characteristics of the junctions  24 , 34 , 52 , 54 . In addition, the compressible foam  60  serves has a layer of protection for the rigid block  62  or panel insulation inside the pocket  66 , protecting the block insulation  62  from impacts. 
     While any block insulation  62  can be used in the pockets  66  of the thermal container  10 , in the preferred embodiment, vacuum panels are employed. Vacuum panels have a higher R factor than typical block insulation  62 . Vacuum panels are generally formed by evacuating the air from a block of open cell insulation. The vacuum is maintained by wrapping the evacuated insulation in an air tight cover. However, such insulation loses much of its thermal benefit if the vacuum is lost. The insulation wrapping can be punctured, and during shipping and storage, the panels may be damaged and the vacuum lost. 
     The compressible insulation  60 , in addition to limiting convection through and around the block insulation  62 , also provides a layer of protection against puncture or tearing. By surrounding the block insulation  62 , the compressible insulation  60  buffers the block insulation  62  from external shocks and impacts. In the preferred embodiment, the compressible insulation  60  is a FLER-4 Ether foam having an average density of 1.65 lbs. 
     In the preferred embodiment, the inside wall  58  and the outside wall  64  of the container  10  are formed of 430 nylon or CORDURA, as manufactured by DuPont. However, any material that is durable under disparate environmental conditions and that can maintain its appearance over time would suffice, including flexible fabrics and rigid shell walls disclosed in application number 09/347,663. Specifically, such material should be resistant to surface abrasions, puncture, water exposure, and other shipping or storage hazards. 
     In the preferred embodiment, the compressible insulation  60  is attached to the inside of the pocket  66  and the wall flap  70 . The preferred compressible insulation  60  is an open cell foam insulation, preferably an FLER-4 Ether, that can be laminated to the fabric by a heat lamination process; however, other compressible insulation  60  and attachment means could be employed. Lamination reduces the number of air pockets between the open cell compressible foam  60  and the outside durable material  58 , 62 , reducing natural convection between the compressible foam  60  and the outside material  58 , 64 . While the lamination process is preferred, other means for attaching the compressible foam to the outer and inner walls may work, such as adhesives or stitching. If desired, the compressible foam  60  may be unattached to the outside material  58 ,  64 . Compressible foam  60  may be secured in the pocket  66  merely by wrapping the compressible foam  60  around the block insulation  62  prior to insertion of the block insulation  62  into the pocket  66 , as taught in application number 09/347,663. 
     The materials used in the preferred embodiment do not have much weight. In fact, in the fully set-up position, only the attachments provide significant pressure on the sidewalls  14 , base  12  and lid  16 . This is where the flexible casing  28  overcomes the problems presented by the thermal junctions  24 , 34 , 52 , 54  and significantly improves the thermal properties of this container  10  over other prior art collapsible containers. 
     When closed around the container  10 , the flexible casing  28  induces a uniform “hoop stress”, compressing the block insulation  62  into the compressible foam insulation lining  60  in all three of length, width and height directions. The flexible casing  28  presses the sidewalls  14  into the base  12  and pushes the lid  16  down onto the sidewalls  14 , improving the seals at the thermal junctions  24 , 34 , 52 , 54 . The compressible foam insulation is then compressed both by the block insulation  62  and by the adjacent sidewall  14   a,    14   b,    14   c,    14   d  and base  12 , thereby improving the thermal properties of the container  10  at the junctions  24 , 34 , 52 , 54 . With the thermal benefits of the present invention, the container can have an R-value of  20  or greater. The preferred embodiment of the present invention, utilizing one inch thick vacuum panels, has been tested to have an R-value of  22  in its fully set-up position. During a test involving frozen foods placed inside the collapsible container  10  of the present invention (i.e., cubing out the container  10  with blocks of ice cream), with the flexible casing  28  closed and zipped, and with an ambient outside temperature of 85 degrees Fahrenheit, the steady state temperature difference between the bottom center of the container  10  and an inside corner of the container  10  measured less than one degree. In addition, with the use of about eight pounds of phase change material described in U.S. Pat. No. 5,976,400, incorporated herein by reference, the ice cream filled container  10  was able to maintain below 0° F. temperatures under the same conditions for more than 24 hours. Though the container  10  is collapsible, the hoop stress placed by the flexible casing  28  significantly reduces thermal loss through the sidewalls  14  and particularly at the thermal junctions  24 , 34 , 52 , 54 . 
     In addition, the flexible casing  28  secures right angle orientation between the base  12 , the sidewalls  14  and the lid  16 , rending the container  10  more rigid and strong. When the flexible casing  28  is zipped closed, the container  10  can withstand over a 100 pounds of pressure acting vertically on the sidewalls  14 . Thus, the container  10  can be shipped through normal channels and endure stacking without collapsing the container  10 , protecting the contents during use. The limiting factor for the stackability or strength of the collapsible container  10  is the compression strength of the vacuum panel or block insulation  62 . 
     The fabric design and structure of the thermal container  10  has the additional advantage of being infinitely scalable. There is no tooling required for manufacturing the container  10 , and no substantial limiting factors as to the size and the availability of the vacuum panel insulation. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, FIG. 10 shows an alternative embodiment of the side wall  14  of the container of FIG. 1, which does not include hinges but rather is fully separable from the rest of the container. The side wall  14  of FIG. 10 still includes a pocket with a closeable pocket opening, and the block insulation can still be a vacuum panel. Velcro  50  can be used to releasably attach the bottom edge  52  of the side wall to the base  12 . Because the flexible casing  28  provides the compressive hoop stress pushing the side wall  14  to the base  12 , thermal losses at the junctions between the side wall  14  and the base  12  can be minimized even with completely detachable side walls.