Abstract:
A novel portable refrigerator is disclosed where the refrigerator is collapsible for storage, comprising a foldable panels for a top, sidewalls, a front, a rear and where all of the panels are attached to a base. One of the panels further includes a chiller circuit that is capable of recirculating the air contained with the refrigerator and cooling it to a selected set point. When in the collapsed mode, the collapsible refrigerator is securable and can be easily handled by the user and stored in a convenient manner.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     The present invention relates to refrigerators and refrigeration systems. More particularly, the present invention relates to a portable refrigerator that is collapsible for convenience in carrying and for storage purposes.  
         [0004]     Since the development of modern refrigeration systems, there has been a constant quest to improve the efficiency of these units in order to reduce size. Improvements in efficiency did transpire and the systems that are offered today are vastly improved over those in existence in the early 1900s. Advances in coolant chemistry and technology, in condenser and evaporator systems, and in the materials used to provide the insulated housing have all contributed to designs for coolers, refrigerators, chiller systems, and the like.  
         [0005]     In recent years, the popularity of portable chiller systems has arisen, perhaps as a result of the extremely mobile American society. These coolers typically look like a tradition ice chest type that a person might use for camping or other recreational pursuits. In the case of the portable chiller type, however, the cooler contains a chiller circuit that is capable of providing refrigeration so long as the power supply to the unit is maintained. Normally, such portable chiller systems utilize both AC and DC power sources, such that when the user is on the road or at a camp site the DC source is taken from the car or motorhome and that mode is used to maintain the portable chiller. Otherwise, if the user happens to be in a location where AC power is handy, such as a hotel room or at a marina with shore power, the portable chiller can be maintained using that power source.  
         [0006]     In any event, the portable chillers referred to still maintain the bulky size and heft of large ice chests even if the size of the chilling systems have been minimized. Advances have been made with respect to ice chests and portable coolers where they have been fabricated from soft-sided materials and can be compacted very easily for storage. However, these constructions do not provide as much insulation as the conventional ice chests and their use is a compromise at best in terms of efficiency versus convenience. In addition, if the soft-sided coolers were fitted with the mechanicals for chilling, the overall structure would be difficult to handle, since part would be rigid and inflexible and part would be compactable and crushable. While such units would fulfill part of the equation for storage purposes, the overall efficiency and effect would not meet the expectations of those users who desired to have the equivalent of a portable chiller that would adequately refrigerate their foodstuffs and drinks.  
         [0007]     In the prior art there have been numerous versions of the portable chiller. These include approaches that utilize traditional chilling circuits whereby a coolant such as a Freon or a Freon substitute, is circulated between an evaporator loop and a condenser loop. In addition, there have been chiller circuits developed that are quite adaptable for portable use, using a thermoelectric chilling/heating system. Both types have been found in the portable chillers that are known and each has its advantage. However, none of the portable chillers in the prior art that have been reviewed are truly compactable or collapsible without some concurrent sacrifice in efficiency, convenience or durability.  
         [0008]     Notwithstanding the advances in chilling systems, there still remains a long felt need for a portable chiller that is very efficient, that retains the durability of solid wall construction and that is compactable or collapsible for convenience and for easy storage. The benefits and attributes of the present invention address this long felt need as well as other deficiencies that are known in the prior art.  
       SUMMARY OF THE INVENTION  
       [0009]     A new portable refrigerator comprises a collapsible housing which is transitionable between a functional mode and a collapsed mode, where the collapsible housing is made up of solid wall construction that is foldable, and where a chilling circuit is integrally included within a solid wall of the portable refrigerator and is directed towards the chilling of the area enclosed by the collapsible housing when it is in the functional mode. When in the collapsed mode, the portable refrigerator folds into a compact size that is easily storable.  
         [0010]     The portable refrigerator of the present invention is capable of being powered by a DC power source.  
         [0011]     The portable refrigerator of the present invention further includes an integrally formed handle that is especially useful for carrying the portable refrigerator when it is in the collapsed mode.  
         [0012]     These and other attributes and benefits of the present invention will be discussed in more detail below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is an isometric view of the portable refrigerator of the present invention as shown in the functional mode.  
         [0014]      FIG. 2  is an isometric view of the portable refrigerator of  FIG. 1 , as shown in the first stage of transition from the functional mode to the collapsed mode.  
         [0015]      FIG. 3  is an isometric view of the portable refrigerator of  FIG. 2  in the next sequential step in the transition of the invention from the functional mode to the collapsed mode.  
         [0016]      FIG. 4  is an isometric view of the portable refrigerator of  FIG. 3  in the next sequential step in the transition of the invention from the functional mode to the collapsed mode.  
         [0017]      FIG. 5  is an isometric view of the portable refrigerator of the  FIGS. 1-4  as shown in the fully collapsed mode and as viewed from the top of the invention.  
         [0018]      FIG. 6  is an isometric view of the portable refrigerator of  FIG. 5  as shown from the bottom side.  
         [0019]      FIG. 7  is a cross sectional view of the portable refrigerator of  FIG. 2 , taken along Section  7 - 7 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     A portable chiller of the present invention is shown in the drawings and is discussed in detail within this section. The terms “chiller” or refrigerator” are essentially interchangeable as used within this specification. Typically, the term “chiller” is meant to convey a chiller circuit which is the conventional approach for coolant-based refrigeration. Chiller circuits employ a coolant supply that is plumbed to run from an evaporator section where the heat is taken up, to a condenser section where heat is blown off, the end result being the ability to cool (or heat) a subject volume. Chiller circuits can be scaled to fit virtually any cooling requirement and in industrial or commercial applications the amount of chilling power is great enough that it is conventionally measured in “tons” of cooling. Conversely, smaller units are in use in the ways described above and essentially work in the same manner and use the same essential chemistry and technology with the scale of cooling power being the only substantive difference.  
         [0021]     In the present case, the chiller of the present invention is a reduced version of the type of chiller circuit that would commonly be associated with refrigerators. The fact that the present invention is meant to operate as a device for the cold storage of foodstuffs means that in essence it is a small refrigerator, nonetheless, it is also an example of a chiller operation. Using alternate technology for the chilling purposes of the present invention is entirely feasible and would not be prohibited. The use of thermoelectric cooling, for example, is an acceptable alternative although the components for thermoelectric chilling will not be shown since they would merely substitute in place of the chiller circuit that is shown, using the same architecture for the supply air and return air systems. Nonetheless it is understood that thermoelectric chilling would be a feasible alternate to the embodiments of the invention as taught herein.  
         [0022]     Turning now to  FIG. 1 , a collapsible refrigerator  10  is shown in the functional mode, i.e., it is fully expanded and is ready for use in receiving foodstuffs and/or drinks and can be powered to provide a refrigerated function. The collapsible refrigerator  10  includes the front wall  12 , the rear wall  14 , the top wall(s)  16 , the base  18 , the sidewall(s)  20 , and the controls  22 . There are also shown Velcro fastening strips  24  running from the base  16  to the front wall  12 . It is understood and seen from the drawings that the collapsible refrigerator  10  encloses a space defined interior to the front wall  12 , the rear wall  14 , the top wall(s)  16 , the base  18 , the sidewall(s)  20 , that is useable for the storage of foodstuffs and the like. This space may be termed the storage space for the purposes within this application.  
         [0023]     In  FIG. 2 , the collapsible refrigerator  10  is shown in the first step of the transition from the functional mode to the collapsed mode, where the sidewalls  20  have been folded over onto the floor  36 . The interior rear wall  26  is shown, with the return air vent  28 , the supply air vent  30 , the top wall living hinge  32  and the sidewall living hinge  34 .  
         [0024]      FIG. 3  continues the stages in transition from the functional mode to the collapsed mode, where the collapsible refrigerator  10  can now been seen with the mid-top wall living hinge  38 , the exhaust vent  40 , the DC supply  42 , the DC supply line  44 , the DC jack  46  and the DC input  48 . The mid-top living hinge  38  separates two of the panels that make up the top wall  16 , and which are identifiable as  16 ( a ) and  16 ( b ).  
         [0025]     Turning now to  FIGS. 5 and 6 , the collapsible refrigerator  10  of the present invention is shown in the collapsed mode, with the handle section  50 , the handle  52 , the rear living hinge  54  and the bottom  56 .  
         [0026]     Lastly,  FIG. 7  portrays the chiller circuit for the collapsible refrigerator with the identification of the major components. Specifically, the chiller circuit  60  includes the chiller housing  58 , the return air plenum  62 , the return air duct  64 , the chilled air blower  66 , the chilled air intake  68 , the chilled air exhaust  70 , the evaporator housing  72 , the evaporator coils  74 , the supply air plenum  76 , the supply air duct  78 , the condenser housing  80 , the condenser  82 , the condenser inlet  84 , the condenser outlet  86 , the hot air exhaust housing  88 , the condenser coils  90 , the hot air exhaust flow  92 , the hot air exhaust blower  94 , the hot air exhaust intake  96 , the hot air exhaust  98  and the hot air exhaust plenum  100 .  
         [0027]     It can now be appreciated that the usage of the collapsible refrigerator  10  of the present invention proceeds in a specific way and with specific benefits. In the functional mode, the front wall  12 , rear wall  14 , top wall  16 , base  18  and the sidewalls  20  are all in the position as shown in  FIG. 1  and serve to form an enclosure that would be useable for the storage of foodstuff and/or drinks. In this mode, the DC supply  42 , via the DC line  44 , the DC jack  46  is brought to the collapsible refrigerator  10  and is supplied through the DC input  48  to the unit. The DC supply as shown is actually a plug that is compatible with insertion into the typical cigarette lighter outlet. In an alternate embodiment, the DC supply could result from a DC transformer of the type that is plugged into an AC power source and this would also service the present invention in entirely the same manner. In the functional mode the user is free to situate the collapsible refrigerator wherever it would be convenient and where a compatible power source would be available. The benefits of this attribute allow the unit to be used in a car, truck, boat, camper, cottage, hotel room, and the like.  
         [0028]     The front wall  12 , rear wall  14 , top wall  16 , base  18  and the sidewalls  20  are made up of solid or semi-solid construction. For instance, they may be comprised of the same construction that is found in the plastic ice chests used for short-term cold storage which typically have plastic panels that sandwich insulating materials therein or merely enclose air space. They could also be constructed from solid panels such as structural foam or even solid plastic or metal, and still achieve the compactable objectives set forth herein although the comparative insulating properties of each may vary in acceptability. The wall constructions that are known in use with modern ice chests are famous both for their insulation properties which would assist the storage of foodstuffs within the collapsible refrigerator of the present invention, as well as promote a very substantial and strong housing for the collapsible refrigerator. Unlike some of the prior art coolers, that have soft-sided construction, the uniqueness of the solid or semi-solid construction of the present invention offer great advantage in strength, in the protection of the contents, and in overall durability. Whether the selection is a solid or semi-solid construction the result is rigid panels that are used to form the various walls (and base) of the present invention. Normally this type of construction would not be subject to compactability but for the teachings of the preferred embodiments of the present invention.  
         [0029]     Given the character of the construction of the collapsible refrigerator herein, the fact that is has been designed to fold into a very small package is a major convenience for the user. Following the progression of the collapsing process, the unit shown in  FIG. 1 . transitions to the version in  FIG. 2  where the sidewalls  20  have been folded inwardly towards the center, and lay on the floor  36 . The folding of such panels is facilitated through the use of living hinges such as the sidewall living hinge  34 . A living hinge is usually associated with plastic construction where a thin plastic connection is retained between tow foldable pieces. The durability of plastics is such that a type of plastic and thickness can be selected for this purpose and will result in excellent service and lifetime. The preferred use of the living hinges in the present invention allows the construction to be fabricated easily and cost effectively. In an alternate mode, other types of hinges can be used, including piano types hinges, however, these are considered to be inferior for applications of this type.  
         [0030]     Turning to  FIG. 3 , the front wall  12  is folded inwardly towards the center of the unit, and it is simultaneously released from contact with the Velcro strips  24  which adhere to corresponding Velcro components (not shown) mounted on the front wall  12 . The top wall  16 , is foldable onto the front wall  12 , as shown, with the individual panels  16 ( a ) and  16 ( b ) being simultaneously being folded as shown to provide a more compact package as at the same time the rear wall  14  is simultaneously being folded inwardly, towards the center of the unit and also towards the front wall  12  which is already resting on top of portions of the sidewalls  20 .  
         [0031]      FIG. 4  shows the collapsible refrigerator in the last stage of the transition from a functional mode to the collapsed mode. As can be seen, the front wall  12  is sandwiched between the sidewalls  20  and the segments forming the top wall  16 ( a ) and  16 ( b ). The rear wall  14  is in the final position resting on top of the sidewalls  20  and nested against the rear edge of the top wall  16 . Similar to the living hinge  34  for the sidewalls, the top wall living hinge  32  allows the rear wall to collapse against the top wall segments in the last stage of the transition. The DC jack  46  is withdrawn from the DC input  48  at some time prior to reaching the collapsed mode.  
         [0032]     The collapsible refrigerator  10  of the present invention, shown in the collapsed mode in  FIGS. 5 and 6 , displays the handle portion  50  which extends along what would have been the bottom side of the rear wall  14  when the rear wall was upright in the functional mode. In the central part of the handle portion is a handle  52  which is shown as a through hole suitable for grasping by a user. In lieu of a formed handle, the present embodiment could be provided with a loop type handle that would be fastened to the handle portion  50 . The Velcro strips  24  have been reattached to corresponding components on the underside of the top wall segment  16 ( a ). This attachment secures the top wall  16  and the rear wall  14  in the stored position and by extension, these keep the sidewalls  20  retained underneath.  
         [0033]     In the collapsed mode, the unit is extremely compact as compared to its size in the functional mode. In fact, in the preferred embodiment, the collapsible refrigerator would be approximately 30″ wide, 12″ tall and about 18″ deep. This would provide ample storage space for the user, although different sized units could easily be provided if demands for smaller or larger capacities were necessary. In the case of the preferred embodiment, the collapsible refrigerator would approximate the size of a closed laptop computer when in the collapsed mode. The preferred embodiment would then be compatible with many of the available storage or carrying cases and it would fit wherever space was anticipated for items like a laptop would be reserved. A storage or carrying case could be supplied with the invention and it would be useful for storing the DC supply and related accessories.  
         [0034]     Turning now to  FIG. 7 , the chiller circuit  60  of the present invention is shown. It is understood that the chiller circuit is preferably designed to run on 12 volt DC current. In use, the chiller circuit is thermostatically controlled by the control  22  which is located on the exterior of the collapsible refrigerator. The control is adjustable and may be set for a range of temperatures, including freezing. The control, no matter what setting, will be able to call the chiller circuit into action when the set point for the desired temperature is breached. The action of the chiller circuit would immediately commence the operation of the chilled air blower  66 , the hot air exhaust blower  94  and the condenser  82 . The chilled air blower will circulate the air contained within the collapsible refrigerator and pass it over the evaporator coils  74  by bringing it into the chilled air intake  68  where it picks it up from the return air plenum  62 , and then distributes it into the evaporator housing  72  after being discharged from the chilled air exhaust  70 . This air flow is chilled when it passes over the evaporator coils and then continues through the supply air plenum  76  into the supply air duct  78  where it is discharged into the interior of the area enclosed by the front wall, rear wall, base, top wall, and sidewalls of the collapsible refrigerator.  
         [0035]     The condenser  82 , when activated as part of the chiller circuit, pumps the coolant (typically Freon or a Freon equivalent) through the evaporator coils where the coolant is optimized for uptaking heat from the air flows passing over the coils. The coolant then proceeds to the condenser coils where the heated coolant is cooled by the passage of the airflows generated by the hot air exhaust blower  94 . These air flows are brought in through vents (not shown) in the hot air exhaust housing  88  and are drawn into the hot air exhaust blower intake  96  and then discharged through the hot air exhaust  98  through the hot air exhaust plenum  100  and then to the outside. This airflow is indicated by the airflow path  92 . The net effect of this exhausting of the hot air is to reduce the heat content of the coolant as it flows through the condenser coils. The coolant continues to flow through the circuit, reaching the condenser inlet  84 , where it recommences the process all over again.  
         [0036]     The circulation of the coolant through the chiller circuit, continuously transfer heat form the recirculated air within the collapsible refrigerator, lowering the air temperature until it reaches the selected set point as determined by the user. The chiller circuit is contained within its own housing which protects the components from damage and also seals those parts of the system that are directing airflows.  
         [0037]     As alluded to above, the chiller circuit of the type shown can be replaced with a thermoelectric chiller without detracting from the function of the present invention. Both may be considered chiller circuits for the purposes of this discussion, however the preferred embodiment is deemed to be the chiller circuit disclosed in  FIG. 7 .  
         [0038]     The features and attributes of the present invention may be achieved with changes to materials, components and by altering dimensions and configurations without departing from the spirit and scope of the teachings herein. To that end, the embodiment illustrated within the drawings and discussed within this specification, and any alternate means for use with the preferred embodiments, are not meant to represent limitations on the scope or claims of the invention.