Abstract:
A shipping container having side walls, a bottom and a top defining an internal volume. The top is selectively displaceable for gaining access to the internal volume and for sealing the internal volume of the container. A valve drawing a vacuum on the internal volume from outside of the container is provided. The side walls are capable of contracting and expanding as a result of the pressure within the internal volume.

Description:
TECHNICAL FIELD 
     The present invention involves a shipping container capable of containing a variety of product sizes and shapes. The container is designed to ship products requiring thermal insulation in order to maintain product integrity throughout the shipping process. The shipping container is capable of being reduced in volume under certain vacuum conditions imposed within the container. 
     BACKGROUND OF THE INVENTION 
     There are a wide variety of containers used for shipping products over conventional channels. Whether shipping is done by air, cargo vessel, rail or truck, all shipping containers must exhibit certain basic characteristics depending upon the product being transported. The present invention deals specifically with containers which are useful in shipping products which are perishable or otherwise require maintaining a somewhat consistent temperature independent of ambient conditions. Most often, containers include cold packs or, in some instances, hot packs and insulative side walls which help to maintain stable temperatures throughout the shipping process. The use of a vacuum to minimize heat transfer is well known. For decades, vacuum bottles have been used having an internal volume and evacuated side walls to reduce thermal transfer. 
     More recently, it has been discussed in the literature that heat transfer can be reduced if the internal volume of a shipping container, as opposed to its side walls, is subjected to vacuum. 
     Specifically, U.S. Pat. No. 5,918,478 is directed to an insulated chest for storage of items at elevated or reduced temperature which has enhanced insulation, and a cover sealed tight by use of vacuum. The separate cover, four sidewalls, and bottom are formed with dual wall construction (relatively heavy plastic with insulation in-between). When the chest is manufactured, the sidewalls and bottom are internally evacuated and sealed to enhance their insulative qualities. After items are placed in the container with charged heating or cooling elements as needed, the hinged cover is closed and a vacuum pump is attached to a valve conduit that passes through the cover so as to draw a vacuum in the container. The vacuum seals the cover onto the chest and enhances the thermal security of the contents. A wrench is inserted into a channel in the cover to turn a valve to a closed positioned so the vacuum pump may be removed with the vacuum maintained in the chest for storage and transportation. 
     U.S. Publication No. 2007/0264485 is directed to several embodiments of enclosures using aerogel insulative blankets for holding a host of different materials. The volume and shape of the enclosure may be determined based on the aerogel material or the internal surface of non-aerogel material. The aerogel material may be an organic, inorganic, or a hybrid of organic/inorganic materials. In one embodiment, insulated strips and labels suitable for insulating beverage containers may be formed, with the insulative quality augmented through the use of vacuum during manufacture of the labels. According to the publication, a rough vacuum in a sealed label of approximately 100 TORR would result in a decrease in thermal conductivity by nearly a factor of 2. 
     U.S. Pat. No. 5,325,281 is directed to an insulated shipping container that uses vacuum insulated panels and expanded polystyrene panels. The container illustrated as a rectangular parallelepiped, is itself formed of four containers that fit snuggly within one another and are easily removed from the assembly to be replaced if damaged. The outer closeable container is formed of corrugated cardboard. Inside this outer container is the first insulating housing that is formed of expanded polystyrene. Within the polystyrene housing is the second insulating housing formed of vacuum insulated panels. Inside this vacuum insulated panel housing is an inner closed container of corrugated cardboard. 
     U.S. Publication No. 2007/0095712 is directed to a shipping container for transporting biologically hazardous materials safely, even at high altitudes. The outer box of the container is intended to be rigid and gas permeable (constructed for example from corrugated cardboard). The outer box includes an inner box constructed of expanded polystyrene foam insulation such as Styrofoam. The interior enclosure is a flexible bag preferably made of polyethylene plastic that is sized so as to be capable of engaging the interior of the exterior enclosure. When biologically hazardous materials are placed within the interior of the bag, the bag is then at least partially evacuated. The bag preferably includes lines providing visual indications to guide its evacuation and seal. 
     U.S. Publication No. 2007/0157564 is directed to a vacuum package system for transporting a plurality of medical containers. The packaging system  10  includes a tray  14  that holds a plurality of medical containers  16 , such as vials. When the containers are disposed in the tray and prepared for shipment, the tray is inserted into an air impervious vacuum bag. A vacuum is applied to the vacuum bag. When fully evacuated, the bag is sealed to embrace the vials and holds them from moving. 
     There are certain limitations inherent in the use of prior shipping containers which have been recognized and addressed in the present disclosure. 
     Recognizing that many products sold in this country are manufactured off shore, shipping volumes become of paramount economic interest. Manufacturers in, for example, Asia, attempt to house as many packages as possible within containers loaded on containerized vessels for transoceanic shipment. Sophisticated shipping containers such as those contemplated herein and in the prior art are provided with valves and insulated walls which occupy shipping volumes which, if reduced, could greatly improve the economies of containerized shipment. As such, it is one object of the present invention to provide a container which can be reduced in volume to the extent practical for maintaining the integrity of the product residing within its internal volume. 
     Yet another issue unaddressed by the prior art involves dealing with changes in internal pressure which inherently occur over time. For example, if dry ice was used as a coolant, the dry ice would sublimate and increase the pressure of the container. Under certain circumstances, a change in pressure could be dealt with by installing a valve through the side wall of the container but, in some instances, that is not a practical solution. Thus, it is yet another object of the present invention to provide a shipping container which can deal effectively with changes in container pressure whether or not a valve is employed. 
     SUMMARY OF THE INVENTION 
     A shipping container having side walls, a bottom and a top defining an internal volume. The top is selectively displaceable for gaining access to the internal volume and for sealing the internal volume of the container. A valve drawing a vacuum on the internal volume from outside of the container is provided. The side walls are capable of contracting and expanding as a result of the pressure within the internal volume. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a perspective view of a shipping container of the present invention opened and within the imposition of a vacuum. 
         FIG. 2  is a perspective view of a shipping container of  FIG. 1  once a vacuum has been imposed on its internal volume. 
         FIG. 3  is the shipping container of the present invention placed within an outer protective shipping box. 
         FIG. 4  is a perspective view of a shipping container of the present invention further including a support frame. 
         FIG. 5  is a perspective view of an alternative support frame to that shown in  FIG. 4 . 
         FIGS. 6A and 6B  are perspective views of an additional embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning first to  FIG. 1 , shipping container  10  is shown comprising side walls having, as a preferred embodiment, inner side wall  15  and outer side wall  14  creating space  16  therebetween, the purpose of which will be discussed hereinafter. The shipping container also includes bottom  25  and top  11 , the latter being displaceable to gain access to internal volume  20 . 
     In operation, one would place the shipping contents within internal volume  20  together with, ideally, a cooling source such as ice, dry ice or a gel pack. Internal volume  20  would then be sealed by placing lid  11  on the side walls as shown. A vacuum would then be drawn through valve  12 . The extent of the vacuum in conjunction with the flexibility of side walls  14  and  15  will determine the extent to which shipping container  10  collapses in volume. Once collapsed, shipping container  10  could simply be shipped as any other shipping container or placed within outer container  30  ( FIG. 3 ) to enhance resistance to damage by external sources such as forklifts, hooks and sharp edges. 
     Once shipping container  10  reaches its ultimate destination and the recipient wishes to gain access to internal volume  20 , air or any other gas can be introduced to internal volume  20  through valve  13 . Once the vacuum is reduced or completely eliminated and internal volume  20  reaches ambient pressure, lid  11  can be easily removed. The present invention has further benefits from those described previously. For example, if the temperature rises in internal volume  20  because, for example, a cooling source becomes exhausted, pressure would build therein. Pressure could also increase if a sublimating solid such as dry ice was used as the cooling source. Not only could increased pressures be vented through optional valve  21 , but expanding side wall  17  having folds  28  could expand thus relieving pressure and maintaining a somewhat vacuum induced condition within internal volume  20 . 
     Further, in knowing the extent of gross shipping volume attributable to a shipment constituting the present invention, one could draw a vacuum through valve  12  to the extent necessary to reduce the external dimension of shipping container  10  until the appropriate dimension is reached. The only practical limitation would involve maintaining sufficient internal volume  20  to allow for receiving the product being shipped and an optional temperature maintaining source. 
     As a further embodiment, it also may be useful to include a heat source within internal volume  20  rather than a cold source if the product being shipped so necessitates. By providing side walls  17  that are collapsible, as the heat source dissipates, temperatures would drop within internal volume  20  and side walls  17  would accommodate reduced pressure by collapsing. 
     As noted previously, the exact extent of volume reduction in using shipping container  10  depends not only upon the relative pressure established within internal volume  20  vis-à-vis ambient pressure, but the resistance of side walls  17  to collapse. This latter variable can be significantly controlled by judicious choice of side wall materials, thicknesses, the extent of folds  28  and what, if anything, exists within space  16  between inner wall  15  and outer wall  14 . For the sake of product integrity, it is generally suggested that portion  18  of side walls  17  near top  11  be made without the present accordion feature as well as portion  19  located proximate bottom  25 . Thus the interface between lid  11  and side wall portion  18  will remain intact as will the footprint established by bottom  25 . 
     As is commonly done, a vacuum could be established between inner side wall  15  and outer side wall  14  within space  16  by providing valve  29  accessible to a vacuum source. Space  16  could also, as a preferred embodiment, be charged with a fire retardant solid, liquid or gas to provide an additional safety feature in using the present invention. Space  16  could also be charged with an insulator, such as Styrofoam. 
     As yet a further embodiment, reference is made to  FIG. 4 . In this embodiment, support frame  55  is shown wrapped about the outside of side walls  51  to add additional structural support to shipping container  50  and to optionally urge side walls  55  into an orientation desired by the user. For example, frame  55  can be biased to resist contraction of side walls  51  by applying frame  55  to the side walls in a compressed orientation whereby the various coils  55   a ,  55   b , etc., urge expansion and thus resist contraction along folds  53 . Conversely, structural member  55  can be applied to side walls  51  in an expanded orientation where loops  55   a ,  55   b , etc., tend to move closer together when not urged apart by side walls  51 . 
     Although shown on the outside of side walls  51 , structural member  55  can be placed on or proximate to the inner side walls of shipping container  50  or between inner and outer side walls in a space akin to space  16  ( FIG. 1 ). 
     An alternative to structural member  55  is shown in  FIG. 6 . In this instance, loops  55 ,  55   b , etc., have been replaced with scissoring members  61 ,  62 , etc., at pivot pin  63  enabling ends  64  and  65  to slide along lower rail  66 . The embodiment of  FIG. 6  would enable one to lock element  61 ,  62 , etc., in place at end points  64  and  65  to fix the appropriate shipping container at a preselected height. This would enable one to reduce the shipping container volume, fix the side wall height using structural member  60  and even if pressure increases within the internal volume of the shipping container urging the side walls to expand, structural member  60  would resist such expansion. This could be helpful in instances where the external dimension of the shipping container is the most important feature characteristic of use. 
     Reference is next made to  FIGS. 6A and 6B  illustrating another embodiment of the present invention. In this embodiment, shipping container  70  is illustrated comprised of outer wall  71  which is rigid and incapable of responding to pressure changes and inner side wall  72  having collapsing in a manner as disclosed with regard to previous embodiments. A vacuum can be drawn on belt  74  through lid  73  causing inner side walls  72  to be drawn towards lid  73  resulting in a reduction in internal volume  76  as depicted in  FIG. 6B . Vacuum can be released through valve  75  to return the  FIG. 6B  configuration to that shown in  FIG. 6A . Such an embodiment will not reduce the external volume of shipping container  70  but will enable one to draw a vacuum within space  76  for the purpose of reducing thermal transfer between space  76  and ambient.