Abstract:
The present invention provides an insulated container that is especially useful in cooling and transporting thermally sensitive materials such as pharmaceuticals, organs, tissues and vaccines. In general, the present invention comprises a container having a base unit and a lid. The container is insulated, preferably through the use of vacuum insulation paneling. 
     A tray holding specimens is placed within the insulated container along with a coolant. To affect the rate at which the coolant draws heat from the specimen within the tray, another competing heat source is placed within the container along with the specimen and coolant. In the preferred embodiment, the competing heat source comprises expanded polystyrene panels coating the inner surface of the insulated container.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to insulated containers and, more particularly, to a shipping container that is especially useful in cooling and transporting thermally sensitive materials such as pharmaceuticals, organs, tissues and vaccines. 
     BACKGROUND OF THE INVENTION 
     It is often desirable and necessary to cool or freeze a specimen in order to preserve it for storage or transport. However, a number of specimens are sensitive to, and can be damaged by, changes in temperature and freezing. The specimens contemplated for use with the present invention can be any material which it is desirable to protect and thermally insulate during transport. Examples of such specimens can be chemicals, organs, tissues, blood, vaccines, food products, or other such materials. 
     For example, freezing a specimen of equine (horse) semen for storage or shipment appears to damage the spermatozoa therein. As a result, the pregnancy rates achieved using frozen (and then thawed) equine semen is a relatively low 50-60 percent. In contrast, the pregnancy rates achieved using horse semen that has been cooled, but not frozen, can be 90 percent or higher. 
     And although cooling equine semen is more effective than freezing it, cooling can also result in damage to a specimen. If an equine semen specimen is cooled too rapidly, thermal shock can cause irreversible damage to the spermatozoa. On the other hand, if the specimen is cooled too slowly, the spermatozoa will be damaged by the prolonged exposure to high temperatures. 
     Accordingly, because the viability of a specimen (such as equine semen) can be affected by the rate at which it is cooled, there is a need for a storage and/or shipping device that can be used to cool a specimen at a controlled and consistent rate. In addition, once the specimen&#39;s target temperature has been reached, the device should be able to maintain the specimen within a desired temperature range for extended periods of time, regardless of the ambient temperature outside the device. 
     SUMMARY OF THE INVENTION 
     In general, the present invention fulfills these needs by providing a device comprising an container having a base unit and a lid. The container is insulated, preferably through the use of vacuum insulation paneling. 
     A tray adapted to hold specimen jars or syringes is placed within the insulated container along with a coolant. To control the rate at which the coolant draws heat from the specimen, one or more competing heat sources are placed within the container along with the specimen and coolant. In the preferred embodiment, the competing heat source comprises expanded polystyrene panels coating the inner surface of the insulated container. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an embodiment of the inventive container; 
     FIG. 2 is a side view of the embodiment of FIG. 1; 
     FIG. 3 is a cross-sectional side view of the embodiment of FIG. 1 taken along line III—III; 
     FIG. 4 is a cross-sectional top view of the embodiment of FIG. 1 taken along line IV—IV; 
     FIG. 5 is a front view of the embodiment of FIG. 1 with dotted lines showing the position of a coolant, tray and cylindrical jar placed therein; 
     FIG. 6 is a side view of the embodiment of FIG. 1 with dotted lines showing the position of a coolant, tray and cylindrical jar placed therein; 
     FIG. 7 is perspective view of the tray of FIGS. 5 and 6; 
     FIG. 8 is a perspective view of the bottom surface of the top half of the tray of FIG. 7; 
     FIG. 9 is a top plane view of the bottom half of the tray of FIG. 7; 
     FIG. 10 is a perspective view of the bottom half of the tray of FIG. 7; 
     FIG. 11 is a perspective view of a specimen syringe; 
     FIG. 12 is a perspective view of a specimen jar; 
     FIG. 13 is a perspective view of another embodiment of the present invention; 
     FIG. 14 is a top plane view of the bottom half of the tray of FIG. 7 with two specimen jars stored therein; and 
     FIG. 15 is a top plane view of the bottom half of the tray of FIG. 7 with two specimen syringes stored therein. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIGS. 1-6, one embodiment of the present invention is a container  1  comprising a base  5  and a lid  10 . In the embodiment shown in FIGS. 1-6, container  1  is a cube-shaped box and base  5  has a bottom wall  15  and side walls  20 . As best seen in FIGS. 3 and 4, lid  10 , bottom wall  15  and side walls  20  define a payload area  25  wherein one or more specimens and a coolant can be stored. In the preferred embodiment shown in FIGS. 1-6, the dimensions of container  1  are 11″×14.25″×8.25″, and the dimensions of the payload area are 7″×10.25″×4.5″. It is also preferred that the top surface of the lid define an indentation  28  for holding documentation concerning the specimen stored within the container. 
     It should be understood that the embodiment shown in FIGS. 1-6 is merely an illustrative example of the present invention, and that a container of any type, shape and size can be used. For example, the container could be cylinder-shaped, such as the container  120  shown in FIG.  13 . 
     Container  1  is insulated to at least partially thermally insulate the contents of the container from the ambient temperature outside of the container. In the embodiment shown in FIGS. 1-6, container  1  is insulated by the use of vacuum insulation panels  30  in lid  10 , bottom wall  15  and side walls  20 . Vacuum insulation panels are well known in the art and are evacuated envelopes surrounding microporous cores having low thermal conductivity. When pressure within the core is reduced enough, the pore divisions significantly interfere with heat transfer through any remaining air, resulting in insulation resistance (R) values of 20-40 per inch. Vacuum insulation panels such as those featured in the preferred embodiment described herein are available from Advantek, Inc. of Minneapolis, Minn. 
     In the preferred embodiment shown in FIGS. 3-4, the vacuum insulation panels  30  are one half inch thick. However, other thicknesses can also be used, depending on the degree of insulation desired. And although vacuum insulation panels are the preferred insulating means for the present invention, other insulators—such as polyurethane or Styrofoam—can also be used. 
     Although not necessary for the present invention, in the preferred embodiment, container  1  features a protective shell  35 . As best seen in FIGS. 3-4, protective shell  35  covers the outer surface of vacuum insulation panels  30  to protect the panels from damage that may occur during shipping or other use of the container. In the embodiment shown in FIGS. 3-4, the protective shell is made from expanded polystyrene. However, any suitable material may be used. 
     To cool a specimen, it is placed within container  1  with a coolant  28 . A specimen can be placed and held in the container  1  in a variety of different ways. Typically, an equine semen specimen is carried in either a syringe  50  (see FIG. 11) or a cylindrical jar  55  (see FIG.  12 ), and the syringe  50  or cylinder jar  55  is then secured within container  1 . If held in a cylindrical jar  55 , the semen is typically placed first in a plastic bag that is then inserted into the cylindrical jar  55  along with a material such as cotton to act as an absorbent and cushion. In the preferred embodiment, syringe  50  or cylindrical jar  55  is secured within a tray  60 , which is then placed within container  1  on top of coolant  28  as shown in FIGS. 5-6. 
     In the preferred embodiment shown in FIGS. 7-10, tray  60  comprises a top half  65  and a bottom half  70 . Preferably, tray  60  is made from expanded polystyrene and dimensioned to fit snugly within the top half of payload area of container  1  atop coolant  28  (as shown in FIGS.  5 - 6 ), i.e. approximately 7″×10.25″×2.5″. However, the tray can be any suitable size and made from any suitable material. It is also preferable that tray  60  feature side concavities  110 , thereby providing areas where the tray can be easily gripped when it is being placed in or removed from container  1 . Holes  115  are provided in the bottom half  70  to provide open communication between the coolant  28  and the specimen(s) stored within tray  60 . 
     Preferably, the tray bottom  70  defines a holding area  75  that can accommodate two syringes or two cylindrical jars. As best seen in FIGS. 9 and 10, holding area  75  is defined by curved side wall  80 , straight side walls  90 , and middle wall segment  85  having end faces  95  and curved side faces  100 . 
     To store a cylindrical jar in the holding area  75 , the cylindrical jar is placed in between one of the curved side walls  80  and the curved side face  100  opposite said curved side wall  80 . Curved side wall  80  and middle wall segment  84  are sized and shaped to engage a cylindrical jar  55  placed between them. FIG. 11 shows two cylindrical jars  55  stored within tray bottom  70  and held in place by curved side walls  80  and middle wall segment  84 . 
     To store a syringe  50  in the holding area  75 , the syringe is placed along one of the straight side walls  90  as shown in FIG.  12 . The syringe is held in place by the selected straight side wall  90  and the end face  95  opposite said straight side wall. In the preferred embodiment, an end notch  105  is provided in curved side wall  80  to accommodate and hold the end  130  of the syringe. A side notch  110  can also be provided in straight side wall  90  to accommodate and hold syringe skirt  125 . 
     The coolant can be any suitable coolant known in the art, including, but not limited to, ice, gelatinized ice, or chemical coolants. In the preferred embodiment the chemical coolant known as the “Thermal Media Pack,” available from Mid-Lands Chemical Co. of Omaha, Nebr., is used. Preferably, the coolant, is placed in the bottom of container  1  and underneath specimen. However, coolant  28  can also be placed above or to the side of the specimen. In addition, depending on the rate and degree of cooling desired, more than one coolant can be placed in the container, in any combination of the positions mentioned herein (for example, two coolants below the specimen, or one above and one below the specimen). 
     To control the rate at which coolant  28  cools the specimen, another competing heat source  40  is placed within the container  1  with the specimen and coolant  28 . For example, the competing heat source can be a thermally active material such as expanded polystyrene. In the preferred embodiment shown in FIGS. 1-4, the competing heat source comprises expanded polystyrene panels  45  placed in container  1  adjacent the inner surface of the vacuum insulation panels  30  in bottom wall  15  and side walls  20 . 
     The amount of expanded polystyrene within the container  1  will affect the rate at which the coolant  28  cools the specimen. The more expanded polystyrene within the container—in other words the larger the competing heat source—the slower the cooling rate. Conversely, if less expanded polystyrene is placed within the container, there is less of a competing heat source and, therefore, the cooling rate is accelerated. Of course, if a tray like that described above is used to store specimens in the container and said tray is made from expanded polystyrene, then the tray will also act as a competing heat source and further slow the cooling rate. 
     For equine semen, the optimum cooling rate is about 0.5° C./minute from 20° C. to 5° C. For the preferred embodiment described above and shown in FIGS. 1-4, it has been found that this cooling rate can be achieved by using expanded polystyrene panels  45  that are approximately three fourths of an inch thick. These polystyrene panels  45 , in combination with the preferred vacuum insulation panels  30  and the preferred tray  60  described above, also result in a container that is able to maintain an equine semen sample at a steady state temperature range of between 4° C. and 10° C. for 100 hours or longer. Of course, different cooling rates and steady state temperatures can be achieved by varying the degree of insulation (such as by varying the thickness of the vacuum insulation panels) and the amount of the competing heat source (such as by varying the thickness of the inner expanded polystyrene panels). 
     While the present invention is described above in connection with specific embodiments, the invention is intended to cover all alternatives, modifications or equivalents that may be included within its sphere and scope, as defined by the appended claims.