Abstract:
A refrigerator includes a refrigerator housing having an open upper end. Fitted beneath the open upper end are a removable cooling unit which has an inlet opening and an outlet opening both in communication with the interior of the refrigerator. The cooling unit draws air into the cooling unit, cools the air, and recirculates it into the refrigerator. The cooling unit can be removed from the lower front end of the housing for repair, and can be replaced with a similar unit so that the refrigerator can continue to be used.

Description:
This claims the benefit of U.S. Provisional Application Ser. No. 61/253,103, filed Oct. 20, 2009 which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     In the prior art, free standing refrigerators are well known. Refrigerators are used for many purposes. They can be used to store and display flowers in a florist shop, food in a grocery store, or other products that require cooling. One commercial variety is used in food-service facilities, mounted beneath a counter or bar area. Such units typically have a refrigerator cabinet with a front access door and a chilled food compartment in which beverages, condiments or other such food containers are maintained in a refrigerated environment, yet allow convenient access to the food therein. 
     The refrigeration system in such a unit includes a conventional compressor, condenser, evaporator and metering device. Typically the refrigeration system is arranged in the cabinet unit so that the evaporator unit, with air circulating fans is included within the refrigeration cabinet, in a central space in the volume thereof, to cool and circulate the air within the cabinet. In this configuration, the compressor and condenser components of the refrigeration system are separately installed at a distance from the evaporator unit and its associated fans within the refrigerator cabinet. Lengths of tubing are required to connect together these elements of the refrigeration system. Commonly, the compressor is located apart from the other components and typically at the rear of the unit. 
     In conventional refrigerators, the refrigerator system or cooling unit is an integral part of the refrigerator. Thus, when the cooling unit breaks down, the entire refrigerator is rendered inoperable. If the refrigerator is located beneath a counter or bar service area, it must be pulled out from its location, the contents removed and the unit serviced all the while it is out of commission. 
     Therefore, a primary object of the present invention is the provision of an improved cooling unit for a refrigerator and a method for using same that avoids such problems. 
     A further object of this invention is the provision of a cooling unit which can be easily removed and replaced in the event that it becomes defective or requires repair. 
     A further object of this invention is the provision of a cooling unit which can be replaced by an identical unit so as to permit the cooled refrigerator to continue to be used while the first cooling unit is being repaired. 
     A further object of this invention is the provision of a cooling unit and method for using same, wherein the cooling unit fits and connects with an air dispersal duct system located within the refrigerator. 
     A further object of this invention is the provision of an improved cooling unit which can be inserted within the refrigerator and removed from the refrigerator when repairs are needed. 
     A further object of this invention is the provision of a cooling unit for refrigerator and method for using same which is economical to manufacture, durable in use, and efficient in operation. 
     SUMMARY OF THE INVENTION 
     These and other objects of the invention have been attained. In one embodiment of this invention, a refrigeration system includes a modular unit separately incorporating conventional elements of a cooling unit (compressor, condenser, evaporator, meter, and fans) in an independent unit which is located beneath, but adjacent to the refrigeration area in a refrigerator cabinet. In this manner, the modular unit provides recirculation of cooled air in the refrigerated area. An advantage achieved, in contrast with prior refrigeration systems, is that the modular system dispenses with the need in the refrigerated area for the separate evaporator and fans, connecting tubing, condensate drain and/or condensate evaporator which have heretofore been located therein in conventional refrigerator systems. Thus, space available for food storage in the refrigeration area is increased and costs and operating difficulties incident to the separation of components of the refrigeration system are avoided. 
     This invention also provides an overall refrigeration system which is easily maintained. In this regard, a self-contained, and independent, modular cooling unit is provided separately from the refrigeration area of the cabinet. Periodic maintenance or emergency service is facilitated because the modular cooling unit containing all the elements of the refrigeration system is easily and separately removable from the overall unit. The modular cooling unit is wholly independent of the cooled refrigeration area of the refrigerator, and may be removed and another substituted in its place. Hence, a breakdown in the refrigeration system will not necessarily result in moving the refrigerator for service or taking the refrigerator cabinet out of service, since modular cooling units are interchangeable. A substitute cooling unit can be provided during the period of service time. 
     Thus, it is a further advantage of this invention to provide a system of standardized refrigeration cooling units which may be utilized at multiple installations at separate locations, in which each cooling unit is separately removable from the refrigerator cabinet, and interchangeable with the other. Hence, service need not be done “on site”, but rather a service facility for an overall system may be centrally located, resulting in a savings of travel time for service persons and a reduction of out of service equipment. 
     This invention utilizes a cooling unit which can be fitted into the open front, bottom area of a refrigerator having a chilled compartment there above for food or other item storage. The cooling unit includes a cooling chamber therein. An inlet opening is provided in the cooling unit for permitting air to enter the cooling chamber, and an outlet opening is provided to permit air to exit from the cooling chamber. A fan is within the cooling unit for causing air to be drawn into the inlet opening, passed over the cooling coil, and forced outwardly through the outlet opening of the cooling unit to the chilled storage compartment. 
     The cooling unit fits beneath the refrigerator with its inlet opening and outlet opening both in communication with the interior chilled storage compartment within the refrigerator. Thus, when the cooling unit is actuated, it draws air from the refrigerator into the cooling chamber of the cooling unit, cools the air, and recirculates the air into the chilled storage compartment. 
     The refrigerator includes a duct system which is registered with the opening of the cooling unit. The duct system includes a lower open end adjacent the bottom of the refrigerator and an upper end in registered alignment with the inlet opening of the cooling unit. This permits air to be drawn from the top of the refrigerator into the cooling unit where it is cooled and then forced outwardly through the outlet opening of the cooling unit and into the bottom area of the chilled storage compartment. 
     The invention includes a cooling unit which can be placed on the floor of the refrigerator. This unit also is adapted to be connected to the duct system of the refrigerator so that cool air is forced into the duct system and carried upwardly to the upper end of the refrigerator chilled storage compartment where it exits and flows down to the cooling unit for cooling. The inlet opening of the cooling unit is adjacent the bottom of the refrigerator, and draws air inwardly at that location. 
     The cooling unit is removable from the refrigerator and the sealing areas between the cooling unit and the refrigerator slope in one embodiment so as they mate together at the same time and seal without the seal dragging along the seal area. Other features of the refrigerator of this invention include a cooling unit that is “front” breathing—meaning it gets all the air it needs for cooling of the equipment from the front of the unit. The cooling unit is also front serviceable in that it is entirely serviceable from the front. Most of the prior art units are serviced from the rear and must be moved for access to the rear of the unit when service is needed. The cooling unit of this invention pulls hot air from the top of the chilled storage compartment and injects cold air into the bottom of the storage compartment. The cooling unit installs in the bottom, front of the refrigerator for convenient access to the upper chilled storage compartment when the refrigerator is beneath a counter. Different cooling units allow for switching from freezer to refrigerator in the same appliance. The refrigerator has duct work running up the back of the appliance to direct and separate the incoming and outgoing air. 
     Other features of the refrigerator of this invention may include an electronic security lock to control user access, a built-in wireless temperature monitor and a built-in wireless user access monitor. The refrigerator may have many uses in a variety of environments, including the food or bar service, hospitality, pharmaceutical, laboratory, medical and other industries. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a front perspective view of one embodiment of a refrigerator with cooling unit installed therein according to this invention; 
         FIG. 2  is a view similar to  FIG. 1  showing the cooling unit being removed from beneath a chilled storage compartment of the refrigerator; 
         FIG. 3  is a cross-sectional view taken along line  3 - 3  of  FIG. 1  showing the airflow between the cooling unit and the chilled storage compartment of the refrigerator; 
         FIG. 4  is a view similar to  FIG. 3  showing the cooling unit being installed into the refrigerator according to one embodiment of this invention; 
         FIG. 5  is a front perspective view of another embodiment of a refrigerator with cooling unit installed therein according to this invention; 
         FIG. 6  is a cross-sectional view taken along line  6 - 6  of  FIG. 5  showing the airflow between the cooling unit and the chilled storage compartment of the refrigerator; and 
         FIG. 7  is a rear perspective, partially assembled view of the cooling unit of the refrigerator of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , one embodiment of a refrigerator  10  with a removable cooling unit  12  according to this invention is shown. The refrigerator  10  includes a housing  14  supported by a pair of downwardly extending legs  16  each having a front edge. The legs  16  are spaced to define there between an open chamber  18 . A bottom floor pan  20  may be provided beneath the chamber  18 . Located above the chamber  18  and supported by the legs  16  is a chilled storage compartment  22  having spaced sidewalls  24 , a top wall  26 , a back wall  28  and a front door  30 . The chilled storage compartment  22  of the refrigerator  10  is cooled by the cooling unit  12  which is selectively installed into the chamber  18  from the front of the refrigerator  10  and beneath the chilled storage compartment  22  and the door  30 . The door  30  is mounted on a pair of hinges  32  which pivotally open and close the door  30  via a latch and handle mechanism  34  for access to the chilled storage compartment  22  as is well known. 
     Also seen in  FIG. 1  are other features of the refrigerator  10  according to one embodiment of this invention including a built-in wireless local area network (LAN) transmitter  36  to transmit data to a central unit (not shown) regarding the refrigerator  10 . Such information may include the temperature history profile of the storage compartment  22 , user access information, energy consumption and other statistical data. Additionally, a digital lock key pad  38  is provided on the front face of the door  30  which may be connected to the LAN to track user access to the refrigerator  10 . The key pad  38  is centered on the door  30  so as not to effect the arrangement and operation should the refrigerator  10  be reconfigured with the hinges  32  and latch  34  on the opposite sides of the door  30  of those shown in  FIG. 1 . 
     As seen in  FIGS. 1 and 2  particularly, the cooling unit  12  includes a front panel  40  that is presented on the front of the refrigerator  10  and beneath the door  30 . The front panel  40  includes a pair of lateral flanges  42  that extend outwardly and are juxtaposed to the front edge of the legs  16 . Locks, bolts or other fasteners  44  secure the flanges  42  into holes  46  in the legs  16  for mounting of the cooling unit  12  in the refrigerator  10 . An intake  48  is located on the front panel  40  through which air is drawn to supply the cooling unit  12 . 
     Referring to  FIG. 2 , one embodiment of the cooling unit  12  and associated front panel  40  are more clearly viewed and include four rollers  50  on the bottom of the unit  12  with each roller  50  positioned proximate a corner of the unit  12 . The rollers  50  assist in the removal and installation of the cooling unit  12  into the chamber  18  beneath the door  30  and chilled storage compartment  22  of the refrigerator  10 . An oval-shaped port  52  is provided in the upper surface of the cooling unit  12  adjacent the back edge thereof. The port  52  is surrounded by a seal  54  which will aid in the mating of the cooling unit  12  and associated port  52  with the remainder of the refrigerator  10  and the flow of air to and between the cooling unit  12  and storage compartment  22 . 
     Referring to  FIGS. 3 and 4 , each of which are cross-sectional views of the refrigerator  10  according to one embodiment of this invention.  FIG. 3  shows the cooling unit  12  installed beneath the storage compartment  22  of the refrigerator  10  and the port  52  of the cooling unit  12  in communication with a plenum  56  adjacent the back wall  28  of the refrigerator  10  to allow for the flow of cool air from the cooling unit  12  as shown by arrows A through the port  52  into the plenum  56  and into the bottom area of the storage compartment  22  as well as return of warm air from the top area of the storage compartment  22  (arrows B) through the plenum  56  and port  52  and into the cooling unit  12  for subsequent re-cooling and return to the storage compartment  22 . 
     The selectively removable cooling unit  12  according to one embodiment of this invention includes a condenser  58  positioned adjacent the front panel  40  and in communication with the intake  48  to draw fresh air into the cooling unit  12 . The cooling unit  12  also includes an evaporator  60  positioned rearwardly in the cooling unit  12  as well as a fan  62  and a compressor  63 . The fan  62  draws the air in the direction of arrow B from the plenum  56  into the cooling unit  12  for processing and returns as chilled air to the chilled storage compartment  22 . Duct work  64  adjacent to the cooling fan  62  keeps the chilled air separate from the air intake from the chilled storage compartment  22 . A power cord  66  and associated coupling  68  are provided to power the cooling unit  12 . 
     The bulk head  70  beneath the storage compartment  22  and above the chamber  18  has a sloped lower surface  72 . Likewise, an upper wall  74  of the cooling unit  12  is similarly sloped such that the height of the cooling unit  12  adjacent the front panel  40  is greater than the height of the cooling unit  12  adjacent the port  52  and back end of the cooling unit  12 . The mating design of the sloped surfaces  72 ,  74  of the bulk head  70  and the cooling unit  12  allow for the sealing areas between these adjacent components to mate together when the cooling unit  12  is fully inserted into the chamber  18  without damage to the seal  54 . The intake  48  in the front panel  40  of the cooling unit  12  allows for substantially all of the air required by the cooling unit  12  to be drawn from the front of the refrigerator  10 . 
     Advantageously, the cooling unit  12  and chamber  18  are positioned below the chilled storage compartment  22  and door  30  to provide more convenient access to the storage compartment  22  when the refrigerator  10  is floor supported or mounted beneath a cabinet, the food service or bar area and between adjacent neighboring (not shown). However, this is only one embodiment of this invention and those of ordinary skill in the art will readily recognize that the arrangement and configuration of the cooling unit, storage compartment and other components of the refrigerator can be rearranged as appropriate for particular environments and installations within the scope of this invention. 
     Referring to  FIGS. 5-7 , an alternative embodiment of the refrigerator  10  with a movable cooling unit  12  according to this invention is shown. Those features, components and aspects of the refrigerator  10  shown in  FIGS. 5-7  which are in common with comparable features, components and aspects of the refrigerator shown in  FIGS. 1-4  will be identified by similar reference numerals throughout the various drawings. Various features of the refrigerator embodiment shown in  FIGS. 5-7  will now be discussed. 
     In the refrigerator  10  shown in  FIGS. 5-7 , the compressor  63  is located adjacent the condenser  58  within the cooling unit  12 . This arrangement improves the compressor  63  performance by locating it in a lower temperature, cooler environment. This aspect of the refrigerator  10  in  FIGS. 5-7  also reduces noise created by the high RPMs generated by the compressor  63 . The compressor  63  as in most refrigerators compresses a refrigerant (not shown) that is in a low-pressure gaseous state to a high-pressure gas. 
     Another difference between the refrigerator  10  of this embodiment and the earlier described embodiment is that the structural components of the cooling unit  12  are constructed from composite or plastic materials. This material difference reduces assembly time and cost for the component as well as noise created by the vibration of metal components which may otherwise be utilized in the manufacture of the components. Moreover, the composite materials provide better installation properties compared to comparable metal components and the manufacturing tolerances required for the various components are much more precise and exact compared to metal components. 
     The arrangement of the components contained within the cooling unit  12  is shown generally in  FIG. 7 . A number, four of which are shown, fans  62  are located along the back of the cooling unit  12 . The fans  62  are located adjacent to the compressor  63  with the condenser  58  positioned generally in the center of the four fans  62 . The condenser receives the high-pressure refrigerant gas from the compressor  63  and converts it to a liquid. As this change occurs, the refrigerant gives off heat, which is conducted away from the condenser  58 . The evaporator is positioned adjacent the front of the cooling unit proximate a number of enlarged vent holes to provide a free flow of air into the unit. The evaporator  60  is connected to the condenser by a capillary tube  61  carrying the refrigerant as a liquid. The refrigerant is injected into larger tubes (not shown) of the evaporator  60  causing a pressure drop. The pressure drop allows the refrigerant to expand back into a gaseous state and such a change absorbs heat. The refrigerant travels via a tube out of the evaporator  60  back to the compressor  63  to repeat the cycle. 
     A control board  76  for operation of the cooling unit  12  is housed adjacent to a dividing wall  78  extending longitudinally across the unit  12 . The compressor  63  and condenser  58  are on the opposite side of the dividing wall  78  from the evaporator  60  to thereby maintain appropriate temperature differentials for efficient operation of the cooling unit  12 . A user control box  80  is mounted on the front panel  40  for access by the user to control the operation of the cooling unit  12  as desired. A blind power coupler  68  is mounted adjacent one of the side walls of the cooling unit  12  and directed rearwardly. The blind power coupler  68  mates with a complimentary power coupler (not shown) facing forward in the housing  14 . The front panel  40  has a pair of laterally extending side flanges  42  as shown in  FIG. 7 . 
     The cooling unit  12  includes a pair of laterally exposed rails  82  each forming a groove  84  along the width of the unit  12  as shown in  FIG. 7 . The cooling unit  12  is easily and accurately installed into the refrigerator  10  when the rails  82  of the cooling unit are aligned with and mate to a base frame member  86 . The base frame member  86  has a pair of inwardly directed toothed rails  88  on opposite lateral edges thereof. Each of the toothed rails  88  of the base frame  86  mate with one of the rails  82  on the cooling unit  12  to guide and center the cooling unit  12  when installed in the refrigerator  10 . A gasket  90  is provided on the rear face of the cooling unit  12  to offer an air-tight seal between the cooling unit  12  and the duct work  64  delivering and returning the air to the storage compartment  22 . 
     Referring to  FIG. 5 , the refrigerator  10  of this embodiment includes a transmitter  36  which is seated within a pocket  92  on the top wall  26  of the housing  14  adjacent the front door  30  of the refrigerator  10 . The transmitter  36  is recessed within the pocket  92 , but exposed for convenient removal, replacement and service as appropriate. The cooling unit  12  likewise includes a pair of handles  94  on the front panel  40  for convenient and easy manipulation of the cooling unit  12  by a user or installer. 
     Referring to  FIG. 6 , the refrigerator  10  of this embodiment includes the cooling unit  12  mounted atop the base frame member  86  as previously described when installed. A bottom overhang flange  96  is provided on the front panel  40  to conceal the base frame  86  when the cooling unit  12  is appropriately installed. Enlarged vent holes  98  are provided on the side wall of the cooling unit  12  to increase air flow and efficiency during operation. The cooling unit  12  includes a condensation collection pan  100  which has a downwardly oriented tiered configuration to direct condensation generated in the cooling unit  12  forwardly and downwardly toward a drain  102  for proper removal. 
     Other features of the refrigerator according to various embodiments of this invention include a low voltage power source which is part of the transmitter&#39;s wire harness so that the transmitter  36  can be primarily powered by available house current delivered to the refrigerator  10 . The refrigerator  10  can operate on 24 volt DC and has a power converter that allows the unit to use a variety of voltages from 100-240 volts 50/60. The refrigerator  10  and associated cooling unit  12  can run directly off of a battery pack (not shown) without the need for a power converter. 
     Another aspect of this invention, the cooling unit  12  for use in the refrigerator  10  typically generates a temperature within the storage compartment  22  as desired by the user and adjusted by the controls  80 . Typically, the refrigerator  12  generates an optimum compartment temperature of greater than 32 degrees and less than ambient. In an additional aspect of this invention, the cooling unit  12  may be removed from the refrigerator  10  and replaced with a cooling unit capable of chilling the storage compartment  22  to a lower temperature and thereby operating the refrigerator as a freezer with reduced temperature storage capabilities, typically less than 32 degrees. As such, this invention is readily adaptable for use as either a refrigerator or a freezer depending upon the cooling unit utilized. Such a modification and other service requirements can be performed on the refrigerator  10  without removal or adjustment of the refrigerator  10  which may be difficult depending upon the space and environment requirements if the unit is located under a work surface, bar service area and/or adjacent neighboring refrigerators, dishwashers or storage areas. 
     From the above disclosure of the general principles of this invention and the preceding detailed description of various embodiments, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, we desire to be limited only by the scope of the following claims and equivalents thereof.