Patent Application
20060191285
Not applicable.
Not applicable.
1. Technical Field
The present invention relates to refrigerated food and drink storage units, and in particular, to compact drawer refrigeration units in which the storage space is defined by one or more pull-out drawers.
2. Description of the Related Art
Refrigerators and freezers for the cold storage of food and beverage items are well known. Many conventional units have one or more doors that are hinged to the front side of the cabinet. Food and beverages are ordinarily stored on shelves in the cabinet and the door(s) as well as in slide-out crisper drawers near the bottom of the cabinet. This is common for industrial and residential refrigerators as either full-size standup units or compact, under-counter units.
Drawer refrigerators are also well known in which the doors are replaced by pull-out drawers having bins in which the food is stored. Drawer refrigerators can be preferred in certain applications, such as low, under-counter applications, because the food items can be pulled out away from surrounding cabinets and accessed more easily. Often such drawer refrigerators have two, or possibly more, pull-out drawers that are arranged side by side or vertically stacked one above the other so that not all of the items are stored in the same drawer.
One problem with drawer refrigerators is that the drawers share a common interior, and thus it is difficult to control the temperature of each drawer, either to set each drawer at the same temperature or to prescribed different temperatures. It is difficult, therefore, to achieve two disparate temperature zones in the same unit, such as would be required for a unit having a freezer drawer and a non-freezer drawer in single cross-ventilated cabinet.
This problem can be avoided largely by isolating each drawer and using two separate evaporator assemblies for each drawer, but at considerable expense. Alternatively, the refrigerator can have a single evaporator, likely at the bottom of the unit, and a dampening system, such as movable louvers. Again, however, this adds considerable expense to the unit as well as occupies additional space in the interior which could otherwise be used for cold storage.
Accordingly, a drawer refrigeration unit is desired that has improved control of the temperature in each zone without requiring each drawer to be completely isolated or independently cooled.
The present invention is a compact drawer type refrigeration unit for the cold storage of food and beverages. Its refrigeration system uses one evaporator to cool at least two zones, in the cabinet in which the drawers are mounted, to different temperatures such that each drawer can be used for different cooling and storage needs. For example, the unit can have one drawer in a refrigerator zone for cooling food and beverages without freezing and another drawer in a freezer zone for storing frozen goods and ice.
Specifically, in one aspect the invention provides a drawer refrigeration unit having a cabinet defining an interior chamber with at least two drawer cavities in each of which is mounted a drawer. The unit's refrigeration system has only one evaporator mounted inside the cabinet in one of the drawer cavities, and an air circulation system transfers air between the cavities to maintain one temperature zone in one of the cavities and another temperature zone in another cavity. The drawer unit can maintain a temperature differential between the two zones of at least 10 degrees Fahrenheit (° F.).
The invention thus provides a slidable drawer refrigeration unit in which the drawers are stacked vertically or arranged side by side and can be pulled from the cabinet to open and close an associated portion of the cabinet for access to the items stored therein.
The refrigeration and circulation system permit the unit to sustain disparate temperatures in a single cabinet of drawers. It can be used thus be used for items that are best stored in different temperature environments. For example, the drawer unit could be a beverage center in which one drawer holds wines, which are best kept at above about 45° F., and the another holds beer or soft drinks, which are best kept at about 35° F. Or, the drawers could hold complementary items, such wine in one drawer and cheese and meets in another drawers which are best kept at just above freezing (about 33° F.).
In another preferred aspect, the invention can provide a drawer refrigerator/freezer. The evaporator maintains both a refrigerator zone where the temperature is above the freezing point of water and a freezer zone where the temperature is below the freezing point of water. The two (or more) drawers slidably mount to the cabinet in the drawer cavities such that one can store refrigerated items and one can store frozen items. The evaporator preferably maintains the refrigerator zone between 33° F. and 45° F. and the freezer zone between about −10° F. and 10° F., with a preferable temperature differential between 30-40° F.
The air circulation system can include a fan that aids in circulating air between the cavities. The evaporator can be mounted inside the cabinet in one of the drawer cavities, for example a lower drawer cavity defining the freezer zone. The fan works to circulate the air in one zone throughout its drawer cavity and also through to the other drawer cavity. By properly controlling the air flow and cooling cycles, the disparate temperature zones can be maintained using a single evaporator and without the need to actively or passively dampen communication between the zones.
Another aspect of the invention is a drawer type refrigeration unit having a built-in ice maker. The ice maker could be of the conventional tray type make or a it could be a clear ice cascading type. In any event, the ice maker would be mounted to the cabinet in the freezer zone. An ice bin can be set in the associated drawer catch the ice from the maker. The bin could then be pulled out with the drawer for easy access to the ice.
These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows are one or more preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to as no one embodiment is intended to fully set forth the scope of the invention.
The present invention generally provides a refrigerated cabinet of drawers for cold storing items, primarily food and beverages. The cabinet holds two or more drawers that can be pulled in and out of the cabinet to access the stored items. The cabinet can mount the drawers in a vertically stacked arrangement or horizontally side-by-side. While the cabinet could hold more than two drawers, it has been found that for many under-counter installations two vertically stacked drawers are preferable.
Cooling and circulation systems allow multiple temperature zones to be established and maintained inside the cabinet. Preferably, each temperature zone is associated with one of the pull-out drawers such that each drawer can provide item-specific cold storage. The temperature differential between the temperature zones, and the range of temperatures in each zone, are designed to be in a range this is both controllable and suited to the items stored in the associated drawers. The drawer unit can thus be used for varied applications depending on the temperature at each zone. The cooling and circulation systems are readily capable of maintaining temperature differentials in the range of 10° F. to 50° F. between two adjacent zones. Although it may be possible to achieve, it is more difficult to control and generally unnecessary to have temperature differentials too far outside of this range.
The drawer unit can provide disparate temperature zones that are either all above, all below, or one or more above and one or more below the freezing point of water. One exemplary application of the drawer unit is as a beverage center. It has been found that soda and beer, for example, are usually best kept at a temperature slightly above freezing, for example 35° F. However, wines are best stored at temperatures ranging from 45° F. to 60° F. depending on the variety. Thus, with the present invention, a single under-counter cabinet can have both a wine drawer and a soda/beer drawer with each beverage type being appropriately cooled. Another example could be a drawer unit for entertaining guests which has one drawer of wine bottles and another which stores meats and cheeses, which are best kept at near freezing, or about 33° F. Likely the most common application for the drawer unit would be as a two drawer refrigerator/freezer unit. As such, the drawings and following text describes one preferred version of such in detail.
Referring now to
The cabinet 14, partition 20 and the drawers 26 and 28 are formed of inner and outer members, of molded plastic or formed metal, with the space therebetween filled with foam insulation as known in the art. A mullion 32 extends across the front opening 18 between the drawers 26 and 28 to support the front edge of the partition 20, which is suitably supported at its side and back edges as well. The mullion 32 can be heated by a low wattage surface heater (not shown) to remove any condensation that may occur during operation.
Each of the drawers 26 and 28 have a front door panel 34 and 35 with a handle 36 and 37 along a top edge. Attached to the door panels 34 and 35 are drawer bins 38 and 39. The drawer bins 38 and 39 can be of the same construction or they may be item-specific in which they are constructed to accommodate a particular item or group of items.
In the preferred drawer refrigerator/freezer 12 shown in the drawings, the refrigerator drawer 26 has opposite side walls 40 joined at their bottom edges to a bottom wall 42 and at their back edges by a vented rear wall 44 that extends only about half the height of the side walls 40 so that its top edge is set down from the top edges of the side walls 40. The low rear wall 44 makes room for a removable bin 50 to be slid forward and backward along the top edges of the side walls 40. The lower space in the refrigerator drawer bin 38 can be partitioned using an adjustable divider fence 52. The slidable bin 50 and the divider fence 52 are described in detail in co-pending U.S. application Ser. No. 10/665,835, filed on Sep. 19, 2003, and assigned to the assignee of the present invention. The corresponding portions of that application are hereby incorporated by reference as though fully set forth herein.
The freezer drawer 28 has a wire basket drawer bin 39 with a stepped bottom 60 that makes the bin 39 shallower at the back end. Stepped sides 62 and a short back 64 define the periphery of the bin 39. The freezer drawer 28 preferably holds an ice bin 70 which has a stepped bottom nested in the drawer bin 39 below an ice maker 72, which is mounted to a side wall at the interior of the cabinet in the freezer drawer cavity 24. The ice maker 72 can be any suitable conventional standard or clear automated ice maker, such as that disclosed in U.S. Pat. No. 4,872,317, the entire disclosure of which is incorporated by reference. The ice maker 72 is connected to a water supply line and as it produces ice the “cubes” fall and are collected in the ice bin 70. The ice bin 70 moves with the freezer drawer 28 so that the ice cubes can be accessed easily.
Turning now to
The refrigeration system 100 has a frost-free evaporator 104 within a housing 106 which is mounted in the interior of the cabinet 14 at the rear of the freezer drawer cavity 24. A circulation fan 108 is also mounted in the housing 106 between an air duct 110 and the evaporator 104. The upper part of the housing 106 has an opening 112 where an upright chimney 114 is mounted to define a vertical air channel at an interior rear wall 116 of the cabinet 14.
The evaporator 104 has an outlet line 120 which passes gas refrigerant to a compressor 122. The output line 123 of the compressor 122 is connected to the inlet of a condenser 124 having an outlet line 126 connected to a dryer 128. A small diameter capillary tube 130 leads from the dryer 128 to an inlet of the evaporator 104. The compressor 122 draws refrigerant from the evaporator 104 and discharges the refrigerant under increased pressure and temperature to the condenser 124. The hot refrigerant gas entering the condenser 124 is cooled by a condenser fan 132 (see
Since the evaporator 104 is disposed in a freezer zone, the refrigeration system includes a defrost cycle in which relatively warm refrigerant is passed through the evaporator 104, which allows it to thaw and clear off any accumulated frost. In this case, a hot gas bypass line 129 runs between the drier 128 and the inlet of the evaporator 104, being in communication with the compressor outlet 123 through the condenser 124. During a defrost cycle, the condenser fan 132 is inactivated so that the hot compressed gas in the condenser 124 is not cooled or liquefied. A normally closed solenoid valve 131 in the bypass line 129 opens so that the evaporator 104 receives the hot gas through the bypass line 129, rather the cooled liquid refrigerant than the capillary tube 130. The hot gas warms the evaporator 104 for a prescribed time period to clear any frost build-up. The evaporator housing 106 acts to shield the heat and minimize warming of the freezer zone during the defrost cycle.
The refrigeration 100 and air circulation 102 systems introduce cooled air into each of the drawer cavities 22 and 24 and are electronically controlled to maintain the associated disparate temperature refrigerator and freezer zones. Because the evaporator 104 is mounted in the freezer drawer cavity 24 the cool the freezer zone will be cooled first and will be maintained at a cooler temperature. The insulated partition 20 divides the interior of the cabinet in two and confines most of the cold air to the freezer drawer cavity 24. Although not necessary, having the colder freezer zone at the bottom of the cabinet aids in keeping the freezer zone cooler due to the fact that relatively warm air is lighter and tends to rise.
As shown in
The refrigerator drawer cavity 22 is cooled by the circulation of the cold air from the freezer zone. The flow of air between the zones is controlled in that it is directed through only the chimney 114 and the return opening 140, and also in that the operation of the circulation fan 108 is controlled. The air flow between the zones is not controlled other than this, and since there are no active or passive dampers that would entirely close off communication between the zones, the zones are in communication with one another at all times, which permits migration of air between the zones within acceptable limits.
A temperature differential between the zones of at least a 10° F. and up to at least a 50° F. can be achieved and sustained by properly controlling the refrigeration and circulation systems. The evaporator preferably maintains the refrigerator zone between about 33° F. and 60° F. and the freezer zone between about −10° F. and 10° F. When used as a general purpose refrigerator/freeze drawer unit, the refrigerator zone is more preferably held between about 34° F. and 45° F. and the freezer zone is more preferably held between about −4° F. and 7° F., with a temperature differential of 38° F., or at least between about 30-40° F. Only when storing special items should either zone need to exceed these ranges, such as when storing bottles of wine.
The refrigeration and circulation systems are operated and controlled by a control unit mounted in the basement of the cabinet 14 outside of the cooled space. A user control 150 mounted inside the refrigerator drawer 26 (best shown in
It should be appreciated that merely one or more preferred embodiments of the invention have been described above. However, many modifications and variations to the preferred embodiment(s) will be apparent to those skilled in the art, which will be within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiment(s). To ascertain the full scope of the invention, the following claims should be referenced.
