HK1093234B - A refrigerator and/or freezer appliance suitable for domestic, industrial, scientific of medical applications - Google Patents

Description

Refrigerator and/or freezer device suitable for domestic, industrial, scientific or medical use

The divisional application is a divisional application of the original invention patent application (application date is 9/13/2000, application number is 00814431.1, and the invention name is "refrigerating equipment").

Technical Field

The present invention relates to refrigeration appliances such as refrigerators and freezers for storing food and other perishable items. Other applications of the invention include the storage of chemical and medical or biological specimens.

The present invention is equally well suited for storing any item in a storage cooled environment, such as in a refrigerated freight car. The term 'device' is thus meant to be very broad, extending from stationary domestic appliances to industrial, scientific and automotive applications. However, much of the description will describe domestic refrigeration appliances for refrigerating food products.

Background

The main reason for keeping food items in a refrigerated state is to delay the deterioration of the food items due to microbial action or physiological or chemical changes in order to extend their shelf life as much as possible. In order to best extend shelf life by refrigeration, several factors must be considered; such as the optimum temperature for storing the food product. In addition, some food products deteriorate rapidly under the attack of highly toxic microorganisms that are easily transmitted to other food products stored nearby, causing cross-contamination. It has long been desirable to isolate different types of food products, and therefore modern refrigerators are often partitioned according to the desires of the user storing the same type of food product in each compartment.

Energy efficiency is also an important consideration in designing such devices, as refrigeration devices consume a significant amount of power when in use. In fact, this is becoming an increasingly important consideration when consumers purchase electrical appliances such as refrigerators, freezers, washing machines and tumble dryers: retailers have responded to this by displaying energy efficiency ratios in front of such devices displayed in their showrooms. Indeed, this is a European (EU) requirement.

A common household refrigerator is a cabinet with a hinged door at the front. The door and cabinet form an airtight enclosure by a magnetically compressible seal. Substantially the entire interior of the cabinet defines a storage space, which is typically divided by several shelves. Access to the shelves may be obtained by opening a door that leads to all shelves. The refrigerator may further include a cooling unit near the top of the refrigerator that cools air circulating as a convective air flow, wherein the air cooled by the cooling unit sinks around the sides of the interior space in the bottom of the refrigerator, and when the air is heated, it rises, passes through the center of the interior, returns to the cooling unit where it is cooled, and thus circulates endlessly.

In order to ensure that the convection of cold air around the entire refrigerator allows all the food products stored to be cooled, the shelves are usually made of iron wire so that they offer less resistance to the passage of air, while still being able to support the stored food products.

While chiller units are used to cool the interior of a freezer to below zero degrees celsius, vertical freezers generally follow the same basic design. Upright refrigerators and freezers are often combined and sold as a single unit, with the refrigerator occupying the top half of the cabinet and the freezer occupying the bottom half, and vice versa. Since the two sections require different temperatures, they can be separated by a solid partition, each section having its own door and cooling unit.

One of the major problems with upright refrigerators and freezers is the upright door. The coldest air will fall to the bottom of the refrigerator or freezer due to its greater density than the warm air. When the door is opened, the cool air is free to flow out of the refrigerator or freezer and is replaced by ambient warm air flowing into the top. Thus, whenever the door is opened, ambient air rushing into the interior of the refrigerator or freezer will cause the refrigerator temperature to rise: this rise must be regulated by operating the cooling unit, thus consuming more energy. Moisture in the incoming ambient air also creates condensation or ice within the cabinet.

Another problem inherent in vertical doors is their associated vertical seal. The coldest air that collects at the bottom of a refrigerator or freezer is always strived to escape the sealing interface, and thus, if a poor seal is formed between the door and the cabinet, the air will escape.

Another common design of freezer is the chest freezer, which, as the name implies, is an open-top chest freezer having a hinged lid that closes the top. Chest freezers are typically separated from the interior by an open wire wall or an open wire basket. As before, both the walls and the baskets are designed to allow the free circulation of cold air through convection and throughout the cabinet.

The chest freezer helps solve the problems of the upright refrigerator and freezer because its lid is not exposed to the coldest and densest air in the same manner. The horizontal configuration is inconvenient and space consuming because it does not allow the use of space just above the freezer which must be reserved for opening the lid. The article cannot be easily removed from the top of the lid. It is well known that large chest freezers are extremely difficult to retrieve and must bend down and move numerous heavy and very cold items to retrieve the items at the bottom of the freezer compartment.

Furthermore, both upright refrigerators and freezers and chest freezers share the following common disadvantages. Typically, a user should only be able to reach a portion of the refrigerator and freezer at a time. However, since the refrigerator or freezer compartment typically has only one shared door or lid, the entire interior is fully exposed to warm ambient air each time the door is opened, and therefore the entire interior must be re-cooled, further consuming energy.

As mentioned above, the advantage of separating different types of food is to avoid cross-contamination. However, separated food products are generally compromised by the convection principles of most refrigerator applications. Since the cool air must cool the stored food, the cool air circulates throughout the refrigerator. Baskets or shelves designed to be substantially open can promote the circulation of air between the compartments and, unfortunately, also the circulation of moisture and harmful bacteria. Furthermore, any liquid that may spill and leak from the food container cannot be stored in the open portion: this is especially problematic when raw meat juices are run out, and cross-contamination is especially severe because of the higher chance of contamination.

As can be appreciated from the foregoing description, it is advantageous to divide the refrigerator into compartments each having its own dedicated door and lid compartment. Examples of such ideas are disclosed in british patents GB602590, GB581121 and GB579071, all issued to Earle, in which cabinet refrigerators are described. The front of the cabinet is provided with a plurality of rectangular openings that receive drawers. Each drawer has a front panel that is larger than its respective opening to form a vertical seal around the overlap when the drawer is in the closed position.

The drawers and the contents thereof are cooled by a chiller unit which circulates chilled air through the cabinet by convection, as in the various refrigerators already described. To facilitate air circulation in all drawers, the drawers are open at the top and have holes at their bottom. Furthermore, the drawers are arranged in a stepped fashion, with the drawers at the top of the refrigerator projecting rearwardly into the cabinet somewhat less than the lower drawers, so that the rear of each drawer is exposed to the cold air flowing downwardly from the chiller unit.

Although only one drawer need be opened at a time, the holes in the bottom allow the cold air to flow freely from the opened drawer and be replaced by warm moist ambient air, thereby compromising energy efficiency and increasing the likelihood of cross-contamination. Indeed, when a drawer is opened, cool air within the cabinet above the drawer will flow out, drawing ambient air into the cabinet. In addition, the drawer encourages ambient air to flow into the interior of the refrigerator because once the drawer is opened, the drawer will act as a piston that draws ambient air into the refrigerator cabinet. Warm air, once present in the cabinet, can circulate freely as cold air is supposed to be there.

Even when closed, the accumulation of cold air towards the bottom of the cabinet will exert greater pressure on the vertical seal of the lowermost drawer, increasing the likelihood of leakage if the seal is defective.

A further embodiment of a refrigerator of the type described above is disclosed in british patent GB602329 also to Earle. The refrigerator disclosed therein also suffers from many of the problems mentioned above, but more interestingly a single drawer consisting of insulated sides and a bottom is provided inside a cooled cabinet. In contrast to the above-described structural variants, the sides and the bottom are solid and not perforated, so that air cannot circulate through the sides and the bottom. When the drawer is closed, a horizontal component within the cabinet, which is thus a lid of the drawer, defines a compartment in combination with the drawer. The compartment is provided with its own cooling coil just below the horizontal assembly.

Little description is given of the seal formed between the drawer and the horizontal member, except that the horizontal member has a downwardly projecting rear end with a biased edge capable of mating with the rear wall of the drawer. There is no other description regarding the connection between the drawer and the horizontal member, except that the drawer is adapted to be 'rather snugly' mounted on the horizontal member when in the closed position. It can be inferred that the drawer and the horizontal assembly are merely abutting each other. While this will prevent the passage of air into and out of the drawer, an impermeable seal will not be formed. Since this is not a gas seal, icing may occur even when the drawer is closed.

The drawer arrangement described forms a compartment in which a temperature different from the temperature prevailing in the rest of the refrigerator can be set. It is specifically contemplated that the drawer may serve as a freezer compartment. The applicant has found that one disadvantage of this arrangement is that the outer surface of the drawer within the cabinet will be cooled to the temperature of the refrigerator, since the freezer drawer remains within the cooling space when the drawer is closed. Thus, when the drawer is opened, these cooled exterior surfaces will be exposed to ambient air containing moisture which will condense on the cooled surfaces, resulting in an undesirable accumulation of moisture. Condensation involves transferring the latent heat of water vapor to the drawer, thus again increasing the cold load on the drawer as it returns to the closed position within the cabinet.

In addition, the condensed moisture is transferred to the inside of the refrigerator when the drawer is closed. As mentioned above, the presence of water promotes the action of microorganisms. Another drawback of introducing water into the interior of the refrigerator is that the water may freeze: this is particularly problematic when the drawer that closes the compartment encounters an insulated top, as any ice formation will form a seal, permanently locking the drawer in the closed position. This drawback is understood when a cam mechanism is provided to break any ice seal that forms according to Earle's recommendation. Forming ice may also affect the sealing ability by preventing the sealing surfaces from properly mating.

Disclosure of Invention

Of course, ice build-up on the moving parts of the drawer mechanism is also undesirable because it will block the movement of the drawer.

The present invention has been devised in view of the above background. In a broad sense, the present invention resides in a refrigerator and/or freezer apparatus suitable for domestic, industrial, scientific or medical use, comprising:

at least one drawer comprising an open-topped insulated container having an outer surface;

an insulating cover adapted to close the open top of the container;

a seal sealing the container and the lid when the container is closed;

a cooling device adapted to cool the interior of the container but not the exterior, the cooling device comprising a heat exchanger associated with the lid or a cold air duct associated with the lid, the cold air duct feeding cold air to the container when the container is closed; and

a structure supporting the drawer, the cover and the cooling device;

wherein the drawer is mounted on the structure and is movable relative to the structure and the lid to open the container to access the interior of the container or to close the container;

at least a majority of the exterior surface of the container is exposed to ambient air when the container is closed by the lid; and

when the cooling means comprise a heat exchanger associated with the cover, the heat exchanger is generally inclined, or has a partially inclined portion, so as to promote the evacuation of the moisture condensed on the heat exchanger from the interior of the container, and the heat exchanger communicates with a duct in the cover or in the container for evacuating the moisture from the heat exchanger.

By exposing the exterior surfaces of the container to air that is warmer than the air contained in the container, these surfaces are maintained at a temperature at which significant condensation can occur. This is in contrast to the prior art, in which the outer surface of the drawer within the cooling compartment is exposed to ambient air only when the drawer is opened, and therefore the outer surface is inevitably cooled sufficiently to cause condensation when the drawer is opened. In the present invention, the problem of condensation on the outer surface does not occur, so that there is no latent heat transfer into the container, and no icing and cross-contamination of the condensed water in the apparatus occurs. Indeed, the outer surface of the container does not experience a significant temperature rise as the container is moved and opened.

The present invention thus provides a refrigeration device having an environmentally exposed surface area enclosing a cooling compartment, wherein most of the surface area moves when the compartment is opened, while a few surfaces remain stationary. This is in contrast to the prior art, where the majority of the surface area exposed to the environment remains fixed when the compartment is opened by moving a small number of surface areas. In this sense, the present invention is directed to conventional techniques.

Preferably, the movement of the drawer relative to the structure and lid includes a substantial substantially horizontal component of movement, for which purpose the drawer may be mounted on the structure by means running along at least one substantially horizontal track. Such a rail suitably comprises a guide rail, which is preferably telescopic.

In addition or alternatively, the drawer may be supported by wheels or rollers that run along a substantially horizontal support surface.

In any case, to assist in the sealing operation, the movement of the drawer relative to the structure and lid preferably includes a secondary substantially vertical component of movement as the container approaches the lid. More specifically, when closed, the container is raised facing the lid, and when open, the container is lowered away from the lid. The rail and the support surface may for example comprise a ramp which reacts to the vertical component of motion.

For best sealing, the apparatus preferably includes a horizontal sealing means to seal the container and lid when the container is closed. Advantageously the seal is compressible and may be operated magnetically, for example by electromagnetic operation. The seal may also be a hydraulic or pneumatic seal.

In order to solve the condensation problem as effectively as possible, it is preferred that substantially all of the outer surface of the container is exposed to the ambient air when the container is closed. The outer surface may comprise several surface portions, for example defined by the container bottom and the side wall. For example, to make better use of space, the container may be substantially cuboidal.

In a very good solution, the cooling means are integrated with the lid. Cleaning is easy if the cooling means is a heat exchanger and is at the same level as the underside of the lid.

The apparatus preferably further comprises closing means for closing the cooling means when the container is closed. This saves energy. The closure means may for example comprise a switch which closes upon the presence of the container, so that the user does not have to remember to operate the closure means each time the container is opened or removed from the structure.

In order to improve the energy consumption and to minimize the cooling of the ambient air in the appliance, it is furthermore preferred that, when the drawer is opened, a retractable screen is provided which extends over the cooling means and is located below the cooling means. For example, the screen may be rolled up on a roller when retracted, and is preferably heat reflective.

To enable automatic extension and retraction, the screen may be attached at one end to the structure and at the other end to the container, or to a device such as a bracket associated with the container, and is advantageously biased in a retracted configuration. If attached to the container, the screen is preferably attached to the container in a manner that is removable from the device so that the container can be removed from the device. In that case, the apparatus suitably includes a retaining means for retaining the screen in a fully or partially extended configuration when the screen is disengaged from the receptacle. However, where a tray arrangement is available, it is possible to keep the screen attached to the tray even when the container is removed from the apparatus.

To remove water or ice from the screen, a wiper or scraper may be provided. The wiper or scraper may function properly during screen retraction.

In order to ensure optimum suitability for storage use, the cooling device is particularly preferably adjustable, so that the same container can be used for refrigeration or freezing.

The structure of the apparatus may be a cabinet and/or may include a frame. The device may suitably be arranged between cabinets or other structures, for example by moving side decorative panels. In any event, it is preferred that the structure and/or any enclosure define at least one ambient air flow path around the exterior surface of the enclosed container.

Means may also be conveniently provided to draw in ambient air from the front of the apparatus and/or to exhaust ambient air from the front of the apparatus. To this end, the structure is capable of defining a front panel including at least one air intake and exhaust port. The front panel also preferably comprises control and/or display means.

To optimize circulation, the apparatus preferably also includes an impeller to facilitate intake and exhaust of ambient air.

Preferably, the container is removable from the structure so that the container can be removed for cleaning or removed from the appliance with chilled or frozen items therein. Thereafter, once the container is removed from the structure, an auxiliary insulating cover or covering is preferably attached to the container. The removed container may be used for picnics, for example, or may be used with a replacement container when additional refrigeration is temporarily required.

In order to provide access to the container from different sides of the apparatus, the drawer is preferably movable in different directions relative to the structure to open the container.

In order to divide and manage the interior of the container storing various items, means for dividing the interior of the container such as partitions, boxes and shelves may also be provided.

In the preferred embodiment, the apparatus of the present invention has a plurality of containers, each container having a corresponding lid and cooling means. In this case it is particularly preferred that the cooling means are preferably independently controlled so that each compartment can be set at a temperature suitable for its contents and that the ratio of refrigerated to frozen storage space can be varied, preferably simply by adjusting the temperature of the compartment above or below a threshold value, i.e. zero degrees celsius. Although this is simple, there may be several refrigerator motors if the individual cooling devices are connected to a common refrigerator motor. For example, there may be a separate refrigerator motor for each compartment.

To emulate the space efficiency, popularity and convenience of a vertical refrigerator or freezer, but not to tolerate many of the disadvantages of the vertical refrigerators described above, the containers are preferably stacked one on top of the other. These containers are adapted to have different internal sizes, shapes and volumes.

Viewing means may be provided to assist a user in viewing the contents of the container. For example, a window may be provided in the front and/or bottom of the container, or a suitably angled mirror may be placed on the container when it is opened.

By providing means to prevent the opening of the container when opening another container, the risk of cross-infection between compartments can almost already be reduced to zero.

Where the apparatus comprises structures such as rails, support surfaces or retrieval screens, these structures are preferably exposed to ambient air so that icing problems do not arise.

In order that the invention may be more readily understood, it will now be described, by way of example, with reference to the accompanying drawings.

Drawings

FIG. 1 is a front elevational view of a refrigerator/freezer unit showing vertically arranged drawers, each of which includes a cabinet;

FIG. 2 is a side view of the apparatus of FIG. 1 with the lower portion of the side panel removed so that the side of the drawer can be seen;

FIG. 3 is a cross-section taken along line III-III of FIG. 2, but with the drawer closed;

FIG. 4 is a cross-section taken along line IV-IV of FIG. 1;

FIG. 5 is an enlarged cross-sectional side view of two drawers in the apparatus of the previous figures, illustrating a method of mounting the drawers on the apparatus;

FIG. 6 is an enlarged cross-sectional side view of two drawers of the apparatus, showing another method of mounting the drawers on the apparatus and one method of removably mounting the cabinet to the drawers;

FIG. 7 is a plan view of the housing and cover of FIG. 6 showing the arrangement of rollers and grooves for mounting the drawer on the apparatus;

FIG. 8 is an enlarged detail view of a portion of two drawers in the apparatus, showing yet another method of mounting the drawers to the apparatus and removably mounting the cabinet to the drawers;

9(a), 9(b) and 9(c) are a series of cross-sectional side views showing a variation in which a drawer is opened by opening a hinged door at the front of the apparatus, the door connecting the drawer, the cabinet being pushed forwardly as the door is opened;

figure 10 is a cross-sectional side view showing another variation in which the drawer is mounted on a sloped support so gravity assists in closing and sealing.

11(a), 11(b), 11(c) and 11(d) are cross-sectional side views of a variation in which a crank helps to raise the chest in sealing engagement with the top seal when the drawer is closed, FIG. 11(a) being a general overview, and FIGS. 11(b) -11(d) being a series of enlarged detail views showing the interaction of the crank and chest as the drawer is moved rearwardly;

FIG. 12 is a schematic side view of portions of an apparatus according to the present invention similar to the variation shown in FIG. 10, except using a horizontal rail and an inclined evaporative cooling device;

FIGS. 13(a) and 13(b) are a cross-sectional plan view and a front view, respectively, showing a modification using one side seal between the case and the cover;

FIGS. 14(a) and 14(b) are schematic cross-sectional side views, with FIG. 14(a) being a general overview and FIG. 14(b) being an enlarged detail view showing a dual action scraper for removing ice or moisture from the evaporator during drawer opening and closing;

FIG. 15 is a cross-sectional side view of another modified doctor blade in which deformation of a flexible membrane is used to facilitate removal of ice and moisture from the evaporator;

FIG. 16 is a schematic cross-sectional side view of a defrost trough in the cabinet for defrosting the evaporator when the drawer is partially closed, the trough capturing water dripping from the evaporator;

FIG. 17 shows a schematic cut-away side view of portions of an apparatus according to the present invention showing a fan coil cooling arrangement for a cabinet, which apparatus can be used with multiple cabinets as well;

FIG. 18 is a schematic cross-sectional side view of the entire cabinet and its cover in another variation of the invention, showing how the cover includes a dish-shaped evaporator that promotes the entry of drain water into the drain channel around the upper peripheral wall of the cabinet;

fig. 19(a) and 19(b) are side and plan views, respectively, of the modified cap of fig. 18.

Detailed Description

Fig. 1-4 show a refrigerator/freezer unit 2 shown as a basic aspect of the invention. The apparatus 2 is of an upright cubic configuration and comprises five front rectangular drawers 4 disposed one above the other and housed in a cabinet 6 comprising a top panel 8, a bottom panel 10, side panels 12 and a rear panel 14. If it is desired to build the apparatus 2 in a seam between other support structures, then no panel as described above is required; in particular, if the side panels 12 can be supported or effected by means of adjacent cabinets, the side panels 12 can be omitted. The panels 8, 10, 12, 14 may or may not be structural members, but if not, a frame (not shown) is required to provide support for the various components of the apparatus. If a frame is provided, it is not structurally necessary to have a panel.

The drawer 4 may slide horizontally into and out of the cabinet 6 using rails on the sides of the drawer 4 as will be described in more detail below. As shown in fig. 2, the drawer 4 can be moved in more than one direction from the cabinet 6 without the back panel 14.

Each drawer 4 comprises an insulated open-topped tub-like container 16, at least one container 16 (in this case the container of the intermediate drawer 4) having a different depth to the other containers 16, defining a different internal volume. In the specific description, these containers 16 will be referred to as boxes 16. There is only a narrow gap between the bottom box 16 and the bottom panel 10 of the cabinet 6, while the top box 16 leaves a substantial space between the top of the appliance 2 below the top panel 8, thus leaving a compartment 18 for housing refrigerator machinery 20 such as known appliances including condensers and compressors.

The deeper boxes 16 of the middle drawer 4 are used to accommodate bottles and other tall items stored upright, while the other shallower boxes 16 are used to store shorter items. All of the cabinets 16 have a better aspect ratio than shelves and other compartments that define the main refrigerated space of conventional upright refrigeration units, i.e., the access opening is considerably wider and thus more accessible than the depth of the compartment. It is very easy to access every portion of the inside of the cabinet 16 when the drawer 4 is opened.

The cabinet 6 is internally divided by five insulating covers 22, one cover being adapted to one drawer 4 and being substantially planar and horizontally arranged. When a drawer 4 is closed, the top opening of its casing 16 is covered by a corresponding lid 22 in a manner to be described. The cover 22 includes a cooling device 24. the cooling device 24 is a known evaporator assembly that is disposed within a lower surface 26 of the cover 22 for cooling the contents of the enclosure 16 enclosed by the cover 22.

Each box 16 has a substantially planar front face 28 which is exposed when the drawer 4 is closed. The front surface 28 may be provided with a well-known trim panel. When the drawer 4 is closed, the front face 28 of the box 16 abuts on top a control and display panel 30 dedicated to the box 16, this panel 30 being coplanar with the front face 28. The panel 30 is supported by a front edge 32 of the respective cover 22, the panel 30 being recessed into the front edge 32 of the cover 22.

The control and display panel 30 contains several displays, switches and audible alarms, thus providing a user interface for each enclosure 16. This interface is most suitable for selecting the temperature of the cabinet 6 to be cooled, for example, and comprises, among other things, temperature display, on/off and snap-off switches, as well as an illumination indication when the drawer 4 is open, and an audible alarm when the opening time of the drawer 4 has been longer than a predetermined time or when the temperature inside the cabinet 6 has reached a higher or lower threshold.

A circular handle 34 extends substantially the full width of the top of the front face 28 to enable the drawer 4 to be pushed out when access to the interior of the bin 6 is required.

The bottom of the front surface 28 of each bin 16 abuts a slot 36 which, as will be described, allows ambient air to enter the cabinet 6. In this way, each slot 36 communicates with an air space 38 extending below the entire bottom surface 40 of the associated bin 16, resulting in a void 42 remaining behind each bin 16, the void 42 being defined by the inner surfaces of the rear and side panels 14, 12 of the cabinet 6 and the rear panel 44 of the bin 16. As can be seen particularly in fig. 4, a void 42 extends from the bottom panel 10 of the cabinet 6 behind each bin 16, communicating with the refrigerator machine compartment 18 at the top of the cabinet 6.

The air space 38 below the tank 16 and the void 42 behind the tank 16 also communicate from the air space 38 to the sides 48 of the tank 16. An opening 46 may optionally be provided in side panel 12 of cabinet 6 adjacent to enclosure 16 through which ambient air can also enter. As shown in more detail in fig. 3 and 4, the air space 38 extends around all of the top sides of the enclosures 16 so that ambient air entering the cabinet 6 through the slots 36 is able to freely circulate around the sides 48, bottom 40 and rear 44 of each enclosure 16. It should be noted that ambient air can freely circulate over the top surface 50 of each lid 22. To allow ambient air to flow over the uppermost lid of the compartment 16 above, a slot 36 may be provided under the front surface 52 of the refrigerator machine compartment 18.

It is worth noting that the piston action of opening the drawer 4 to draw ambient air into the interior of the device 2 does not cause problems. In fact, this effect is advantageous since it promotes the circulation of ambient air inside the cabinet 6.

Fig. 4 shows that the refrigerator machine compartment 18 includes an impeller 54 that vents through an aperture 56 provided in the front face 52 of the refrigerator machine compartment 18. As best shown in fig. 1, these apertures 56 extend horizontally the entire width of the front surface 52. The impeller 54 communicates with the space 42 behind the housing 16 to draw air from the space 42, thereby continuously causing ambient air to be drawn in through the slots 36 and the vents 46 on either side. Once inside the refrigerator machine compartment 18, the air thus passes through the heat exchange body 58 of the condenser.

Thus, if the front slot 36 is provided, ambient air entering the cabinet 6 through the front slot 36 and the side vents 46 exits the cabinet 6 through the apertures 56 provided in the front face 52 of the refrigerator machine compartment 18, and thus circulates throughout the cabinet 6. More specifically, ambient air enters the apparatus 2 and immediately contacts the exterior surfaces 40, 44, 48 of the enclosure 16 therein and heats these exterior surfaces to ambient temperature (or substantially ambient temperature) before the circulating air is drawn downwardly into the void 42 and then upwardly through the void 42, with the arrows in FIG. 4 indicating the circulation of air throughout the apparatus 2. Thus, the interior of the cabinet 6 is maintained at near ambient temperature and only the interior of each enclosure 16 is cooled.

By exposing the exterior surfaces 28, 40, 44, 48 of the enclosure 16 to air that is warmer than the contents thereof, there is no problem of condensation on the exterior surfaces 28, 40, 44, 48, and therefore potential heat transfer to the enclosure 16 or icing, and cross contamination of the condensate entering the cabinet 6.

In any case, cross-contamination is not possible, since each box 16 is tightly sealed when its drawer 4 is closed. Thus, even bacteria entering the cabinet 6 cannot immediately enter the other boxes 16. It is also not possible for both cases to be opened simultaneously at any given time. Reinforcement means may also be provided, for example using a mechanism similar to that used in filing cabinets to prevent more than one drawer 4 from being opened simultaneously.

The open top of one of the cabinets 16 does not leak much cold air when opened, and the horizontal seal 60, which is convenient to use, is inherently better at sealing cold air than the vertical seal common to upright refrigerators and freezers when one of the cabinets 16 is closed. Although horizontal seals are known in chest freezers, the apparatus does not suffer from the inconvenience and space problems of chest freezers, such as the particularly popular upright type of apparatus.

Because of the large temperature gradient that exists between the cooled inner surface 62 of each tank 16 and its outer surface 28, 40, 44, 48, the tanks 16 are constructed of a good performing insulating material to facilitate maintaining the temperature gradient and maintaining the outer surface 28, 40, 44, 48 at or near ambient temperature. As the material constituting the tank 16, particularly preferred are materials such as phenol foam or urethane foam (optionally coated with GRP or polycarbonate of a composite structure).

If it is desired to isolate the contents of a particular bin 16, that bin 16 may be fitted with a removable insert 64. The shape and size of these inserts 64 may vary and may be used to define a variety of compartments. For example, the insert 64 may be a thin partition having a length corresponding to the length or width of the housing 16 in which it is housed. The insert 64 may be a covered or uncovered box or the insert 4 may have clips for holding bottles or trays for eggs, etc. The insert 64 may also be a wire basket or shelf.

One or more of the housings 16 may be removed from the apparatus 2 and fitted with an insulating cover 66, as shown in figure 2. The box 16 is removable from the apparatus 2 and its insulating structure ensures that the contents thereof remain cool for a defined period of time. For example, the bin 16 may be used as a cold box, able to be combined with an ice pack, keeping the interior as cool as possible. Alternatively, the box 16 with the cover 66 may be held adjacent to the appliance 2 to provide additional temporary refrigeration capacity, in which case the box 16 is mounted on the appliance 2.

The cover 66 may also include an internally powered refrigerator motor supplied by batteries or air supply, or externally supplied by mains electricity or vehicle electricity.

The internal connections between the drawer 4 and the box 16 and the lid 22 are shown in detail in figures 5, 6 and 7. Fig. 5 shows the drawer 4 of the apparatus described above with reference to fig. 1-4, while fig. 6 and 7 depict another alternative. Common features thereof will be described below, and differences therebetween will be discussed later.

Figures 5, 6 and 8 clearly show how the relative lid 22 closes the open top of the cabinet 16 when the drawer 4 is in the closed position. A compressible seal 60 is provided under the lid 22, the seal 60 being sized and positioned to correspond to the top edge 68 of the cabinet 16, which is directly under the seal 60 when the drawer 4 is closed. The seal 60 may be magnetic, e.g. electromagnetically operable, or may be sealed using hydraulics and pneumatics as described above. When the container 16 is closed, the container 16 compresses the seal 60 to form an air-tight seal between the lid 22 and the container 16. In this way, the box 16 is moved upwards at the end of the closing movement. All the main differences between fig. 5 and fig. 6, 7 and 8 are in how the upward movement is obtained.

Figures 5 and 6 also show how the bottom of the cover 26 accommodates the heat exchanger 24 inside the cooling tank 16. The heat exchanger 24 is located in the central lower portion of the tank 16 and occupies most of the area of the underside of the cover 22. The bottom surface of the heat exchanger 24 is flat and substantially coplanar with the bottom surface around the lid 26, ensuring that the entire bottom surface of the lid can be easily cleaned.

The heat exchanger 24 is controlled by a control assembly on a control and display panel 30, which panel 30 is recessed into the front edge 32 of the cover 22, whereby a selected temperature can be set, and the heat exchanger operated accordingly. A temperature sensor (not shown) is provided which operates in a known manner through a feedback loop to change the operating conditions of the heat exchanger when it is desired to maintain a selected temperature. The heat exchangers 24 are connected to the refrigerator motor 20, which is also connected to all the other heat exchangers 24 of the apparatus, and the system is also provided with valve means controlled by the respective control assembly to adjust the cooling effect of each heat exchanger 24 according to the operating conditions selected by the user to be required.

It will be appreciated that each bin 16 includes a separate, independent refrigerated area. Therefore, the temperature can be set independently, and if necessary, different temperatures can be set for each tank 16. In fact, the temperature may be set below 0 ℃, so that the cabinet 16 may be used as a freezer or refrigerator at the option of the user. In this way, the apparatus 2 can be used as a combined refrigerator and freezer cabinet in which the ratio of refrigerated and frozen spaces can be conveniently and advantageously varied by varying the use of one or more compartments 16. It will of course be appreciated that the drawers 4 may all be used as refrigerators or all as freezers, and that in effect the apparatus 2 may also be used exclusively as a refrigerator or freezer.

As will be seen from fig. 5 and 6, each drawer 16 is provided with a screen 70, the screen 70 being made from a thin flexible sheet of material. The purpose of the screen 70 is to underlie the exposed heat exchanger 24 and also rest against the cold bottom surface 26 of the lid 22 when the drawer 4 is opened. The objective is to prevent as much as possible heating of the bottom surface 26 of the lid 22 or cooling of the air at substantially ambient temperature within the cabinet 6.

In the illustrated arrangement, the screen 70 is a flexible sheet rolled up on a roller 72 when the drawer 4 is closed, and can therefore be compactly stored in the space 42 at the rear of the cabinet 16 exposed to the environment. Each spool 72 is adjacent the lower rear edge of each cover 22, with each spool 72 and its respective screen 70 extending across the width of the cover 22.

The front edge 74 of each screen 70 is movably attached to the upper portion of the rear surface 44 of the respective cabinet 16 so that when the drawer 4 is opened, the screen 70 is pulled forward with the cabinet 16. When the drawer 4 is opened, the screen 70 does not unwind from the spool 72 and does not form a flat surface directly beneath the lid 22. When the drawer 4 is returned to its closed position, the screen 70 is rolled up on the roller 72 as described above, for which purpose the roller 72 is tilted in the rolling direction.

Thus, only a small amount of air occupies the gap between the cover 22 and the screen 70, which is advantageous because this air will be cooled by the proximity of the cover 22. The screen 70 is preferably made of silver or other reflective plastic in order to prevent heat transfer from the warm ambient air in the large gap left by the open drawer 16 to the small amount of cold air between the screen 70 and the heat exchanger 24. Thus, when the drawer 4 is returned to the closed position, only a small amount of cooled air remains in the cabinet 6, compared to a large amount of warm ambient air, causing only a negligible drop in temperature, which drop is soon compensated for by a further consumption of ambient air flowing into the cabinet 6.

Although designed to be heat reflective and insulating, the underside of the screen 70 is somewhat susceptible to cooling when the associated drawer 4 is opened. This can cause condensation or icing on the underside of the screen 70. To eliminate this condensation or ice, a scraper in the form of a plastic blade is pressed against the screen 70, which is wound on a reel 72. When the drawer 4 is closed, the screen 70 moves over the scraper 76 and the condensate will move down or over to the underside of the scraper 76 and will be collected in the drain 78.

A slight difference between fig. 5 and fig. 6 and 8 is that fig. 5 shows the scraper 76 and the drain 78, which are not shown in fig. 6 and 8. It will be apparent that the scraper 76 and drain 78 could equally well be used in the apparatus of figures 6, 7 and 8 if desired.

In order to minimize the loss of cold air and the loss of cooling of the ambient air, a closing device is also provided for closing the heat exchanger 24 when the respective drawer 4 is opened. These means can comprise a contact switch (not shown) located at the rear of the lid 22, against which the rear plate 44 of the box 16 presses, closing the switch when the drawer 4 is closed. When the drawer is opened, the contacts are opened and the heat exchanger 24 is disconnected until the drawer 4 is closed again. This is particularly useful when the tank 16 is removed from the apparatus 2 for a period of time, so that the user does not have to remember to switch off the heat exchanger 24 concerned.

Referring now to features of the apparatus of fig. 1-5, the mechanism for opening and closing the drawer 4 includes a pair of rails 80, 82 disposed on each side panel 48 of the housing 16 for supporting the housing 16 when the housing 16 is opened. The rails 80, 82 are attached to the side panels 12 of the cabinet 6 and are preferably arranged one above the other on each side of the enclosure 16 as shown in figure 3.

Four rollers 84, 86 are mounted on the side 48 of the cabinet 16 and engage respective rails 80, 82. The rollers 84, 86 are shown only on the lower housing 16 in fig. 5 and are arranged in two pairs, a front pair 84 and a rear pair 86, the front pair 84 being lower than the rear pair 86 so that the rear pair 86 engages the upper track 80 and the front pair 84 engages the lower track 82. Only one roller of each pair of rollers 84, 86 can be seen in the side view of fig. 5.

At least the lower rail 82 is telescopic to maintain engagement with the front roller 84 when the drawer 4 is opened. The rear ends of all of the rails 80 and 82 terminate in a ledge 88 behind the ramp 90 so that when the drawer 4 is closed, the rollers 84 and 86 move rearwardly along the respective rails 80 and 82, riding up the ramp 90, and reaching the ledge 88. As such, the bin 16 moves upwardly near the end of its horizontal rearward stroke, and thus its top edge 68 is forced upwardly against the associated seal 60. Conversely, when the rollers 84 and 86 move forward along the rails 80 and 82 as the drawer 4 is opened, the rollers 80 and 82 move rearward, away from the ramp 90, and away from the seal 60, and away from the enclosure 16.

The box 16 may also optionally include four lower rollers 92, 94 mounted at the bottom of the box 16. The lower rollers 92, 94 are also shown as only one on the lower box 16 of fig. 5 and are arranged in two pairs, a front pair 92 and a rear pair 94. As previously mentioned, only one lower roller of each pair of rollers 92, 94 is visible in the side view of FIG. 5.

The lower rollers 92, 94 move on a support surface that is underneath the top of the lid 22 or, in the absence of the lid 22 underneath the bottom drawer 4, on the top surface of the bottom panel 10.

The lower rollers 92, 94 move rearward along the support surface when the drawer 4 is closed. When the drawer is nearly closed, each roller 92, 94 moves onto a ramp 96 (only one rear ramp 96 is visible in fig. 5) supporting upward movement of the cabinet 16 near the end of its horizontal rearward movement.

Turning now to the apparatus shown in figures 6 and 7, many of the features are the same as in the apparatus of figures 1 to 5 and therefore like parts are indicated by like reference numerals. As above, the telescopic rail 100 supports the drawer 4 open, but in this case the rail 100 is adapted to allow the casing 16 to be removed from the apparatus 2. The box 16 is therefore provided with two projections 102 on each side, the projections 102 being received in two correspondingly shaped slots 104 of the rail 100. The projection 102 and the slot 104 extend vertically and have a circular bottom edge 106: the rounded bottom edge 106 of the tab 102 helps to place the tab 102 in the slot 104 when a cassette 16 is returned to the device 2.

The telescopic rail 100 is a two-piece structure. The outer rail 108 is connected to the adjacent side panel 12 of the cabinet 6 and therefore remains stationary in use, whilst the inner rail 110 with the slot 104 moves back and forth as the drawer 4 is opened and closed. Since guide rail 100 remains inside cabinet 6, which maintains and approaches the ambient temperature, the problem of blocking the sliding movement of guide rail 100 due to icing does not occur.

In addition to the lowermost drawer 4, in which rollers 112 and 114 are mounted on top of the bottom panel 10 of cabinet 6 of the lowermost drawer 4, the cabinet 16 is also supported from below by four rollers 112, 114 mounted on top of the lower lid 22 of the cabinet 16 when the drawer 4 is fully or partially closed. The rollers 112, 114 are of sufficient diameter to span the air gap 38 beneath each cassette 16 and are arranged in two pairs, a front pair 112 and a rear pair 114.

As shown in the plan view of FIG. 7, the front pair of rollers 112 are closer together and are aligned with parallel slots 116 provided in the underside 40 of the housing 16, the slots 116 extending from the rear edge of the underside 40 to near the front edge of the underside 40 and terminating in an angled end surface 118. The slot 116 receives the front pair of rollers 112 when the drawer 4 is opened, as in the lower drawer 4 of fig. 6. Notably, the carriage 16 is moved away from the rear pair of rollers 14 in this position. Since there are no rollers 112, 114 supported on the box 16 in this position, their weight is entirely supported by the rail 100, with the projection 102 at the bottom of the slot 104.

When the drawer 4 is closed, the box 16 moves horizontally rearward on its rail 100 and the rollers 112, 114 come out of contact with the box 16. But when the drawer is nearly closed, the rear roller 114 contacts the rounded lower rear edge 120 of the cabinet 16. The length of the slot 116 is set so that the rear roller 114 contacts the lower rear edge 120 of the bin 16 and the front roller 112 contacts the angled end surface 118 of the slot 116. Thus, as the drawer 4 is again pushed back to its closed position, the rounded lower rear edge 120 of the cabinet 16 and the inclined end surface 118 of the slot 116 ride on the rollers 112, 114 and the cabinet 16 is thus raised. The projection 102 rides in the groove 104 and thus allows such movement wherein the top edge 68 of the tank 16 is forced against the compressible seal 60. In this position, the weight of the bin 16 and articles therein is removed from the rail 110 and borne by the rollers 112, 114.

Conversely, when the drawer 4 is opened, the box 16 moves downward and forward due to the lower rear edge 120 being clear of the rear roller 114, the front roller 112 again being received by the slot 116. Once clear of rollers 112, 114, bin 16 supported on track 100 is free to move to its fully open position supported by track 100.

When the case 16 is removed and installed on the device 2, both operations can be performed with the drawer 4 in its fully open position with the screen 70, even if the screen is fully extended. To remove the enclosure 16, the front edge 74 of the screen 70 is disengaged from the enclosure 16 and supported by a retaining means in the form of a clip or other suitable retaining structure (not shown) that relies on the cover 22.

Reference is now made to the apparatus shown in figure 8, in which many of the features are the same as those of the apparatus of figures 1 to 7, and therefore like parts are indicated by like reference numerals. The apparatus of figure 8 is closest to that of figures 6 and 7 in that the same cartridge and sealing mechanism are used. This includes the inner rail 110 and the outer rail 108 in the apparatus.

The main difference with the device of figure 8 is how the casing 16 is removably mounted on the relative drawer 4. It can be seen that the inner track 110 is attached to side arms 122 of a bracket 124 that surrounds and supports the lower portion of the housing 16, wherein the bracket 124 also has front and rear retainers 126 and a bottom support 128 at the ends.

The cabinet 16 is mounted within the bracket 124 when the drawer 4 is in the open position. The bottom 40 of the housing 16 rests on the support 128 and the sides 44 of the housing 16 are retained within the retainer 126 and the arms 122. When the drawer is in the open position, the housing 16 is fully seated in the bracket 124, and thus the top 68 of the housing 16 is clear of the seal 60, allowing the rollers 112 to be received in the slots 116.

As with the apparatus of fig. 6 and 7, when the drawer 4 is closed, the cabinet 16 moves rearwardly into the cabinet 6, and when in almost its closed position, the movement of the rounded lower edge 120 of the cabinet 16 and the sloping end surface 118 of the slot 116 over the rollers 112, 114 will cause the cabinet 16 to rise, compressing the seal 60. As the bin 16 is raised, it rises within the tray 124, supported only by the rollers 112, 114.

Although a screen is not shown in fig. 8, the apparatus can also advantageously allow the front edge 74 of the screen 70 to be attached to the portion of the carrier 124 of the associated drawer 4. In this way, the screen 70 may be placed while still attached to the bracket 124, regardless of whether the enclosure 16 is still within the bracket 124, and therefore, regardless of whether the enclosure 16 is located within the drawer 4 or removed from the drawer 4, without having to attach the screen to the enclosure 16 or detach the screen from the enclosure 16.

Fig. 9(a), 9(b), and 9(c) show a variation of the apparatus in which a hinged door 130 defining the front wall of the drawer 4 of the apparatus can be opened from a vertical position to a horizontal position, and the cabinet 16 can be slid forward and removed from the drawer 4 without lifting the cabinet 16. The door 130 is hinged along its lower edge, and when the armrest 132 on the top front edge of the door 130 is pushed, the door 130 swings downward by 90 degrees as shown in fig. 9 (b). The drawer 4 can be opened by normally pushing the handle 132.

As previously described, the drawer 4 runs on telescopic rails 100 (only one can be seen from the side view), but in this case the front end of each rail 100 carries a respective slotted rail 134 defining a slot 136 that extends up and down and perpendicular to the telescopic direction of the rails 100. The link 138 is pivotally connected at a first end to the door 130 near an upper edge of the rear edge of the armrest 132. The opposite second end of the link 138 is constrained to move within the slot 136 defined by the guide rail 134 so that it is at or near the bottom end of the slot 136 when the door 130 is closed as shown in fig. 9(a) and abuts the top of the slot 136 when the door 130 is opened as shown in fig. 9 (b). This abutment suitably prevents the door 130 from opening more than 90 degrees, thus horizontally supporting the open door 130 in a manner that can support the weight of the load box 16 as shown in fig. 9 (c).

As the second end of link 138 moves upwardly along slot 136 in rail 134 when door 130 is opened, link 138 pushes on rail 134 so that the attached end of rail 100 moves forwardly along with cabinet 16 carried by rail 100. This is shown in fig. 9 (b). However, forward movement of the bin 16 may continue as shown in FIG. 9(c), which shows the bin 16 sliding away from the extended track 100, using the horizontal rear surface of the open door 130 as a support for continued sliding movement of the bin 16.

Figures 10 and 11 show a top seal variation in which another means is provided to assist in compressing the seal 60 by raising the bin 16 when the bin is closed. The variant of fig. 10 also uses means for biasing the drawer 4 to the closed position, both functions being well performed in fig. 10 by closing the drawer 4 using gravity and compressing the seal 60. In particular, the variation of fig. 10 contemplates mounting the drawer 4 on inclined rollers, rails or supports 140 that are inclined downwardly toward the rear of the apparatus so that the drawer 4 tends to slide rearwardly and downwardly into a closed position. This inclination (which is greatly exaggerated in fig. 10 for ease of description) serves to offset the drawer 4 from the open position of the lower drawer 4 of fig. 10 into the closed position of the upper drawer 4 of fig. 10.

It will also be noted from figure 10 that the lid 22 and the opposite side rail, rail or support 140 are non-parallel and the distance between them decreases progressively towards the rear, defining a trapezoidal gap narrowing at the rear, accommodating the cabinet 16 when the drawer 4 is closed, as shown in the upper drawer of figure 10. As a result, although the box 16 slides in absolute value downwards as it moves backwards, the box 16 also moves relatively upwards to tilt or wedge against the associated lid 22 and thereby compress the seal when the drawer 4 is closed.

In the variation of fig. 11(a) -11(d), the crank 142 helps to lift the bin 16 into sealing engagement with the horizontal top seal 60 when the drawer 4 is closed. The crank 142 associated with a particular drawer 4 is pivotally connected to the lid 22 of the underlying drawer 4, supporting the lid 22 near its rear end. More specifically, the crank 142 is supported in the path of the cabinet 16 so as to engage the rear of the cabinet 16 when the associated drawer 4 is near its fully closed position.

As best seen in the enlarged views of fig. 11(b) -11(d), the crank 142 is generally U-shaped and includes an L-shaped actuating lever 144 connected to a lifting arm 148 at a pivot 146, which terminates in a roller 150 and completes the U-shape. The crank 142 is biased into the upright position shown in figures 11(a) and 11(b) in which the free end of the actuating lever 144 is extended forwardly and the lifting arm 148 is correspondingly retracted parallel to the free end of the actuating lever 144 and the upper surface of the lid 22. In this retracted state, the lifting arm 148 and its associated roller 150 are sufficiently close to the lid 22 to fit within the slot under the cabinet 16 via the front roller 152. Thus, when the lift arms 148 are retracted, the lower rear edge of the rearwardly moving bin 16 can ride on the rollers 150. Thus, the rear surface of the cabinet 16 bears against the free end portion of the actuating lever 144 as shown in FIG. 11(c), causing the crank 142 to rotate, raising the lifting arm/roller 148/150 out of the retracted position, thereby lifting the cabinet 16 until the drawer 4 is fully closed and the cabinet 16 is sufficiently raised, as shown in FIG. 11 (d).

The variant according to fig. 12 of the invention is identical to the variant of fig. 10 in that there is a wedge-shaped gap between the cover 22 and the rearwardly moving guide 100, but in this case the guide 100 is horizontal, only the cover 22 being inclined. The result is that the casing 16 is wedge-shaped, wedging in the wedge-shaped gap when the associated drawer 4 is closed, thereby compressing the seal 60 between the lid and the casing 16. The seal 60 is held in compression by a latch, hook or magnet, preventing the case 16 from moving away from the lid 22 until access to the case 16 is desired. Fig. 12 contemplates magnetic sealing assisted by a hook 154 engaging the lower front edge of the cabinet 16 when the drawer 4 is closed.

The benefit of the variation in fig. 10 and 12 is that the inclination of the cover 22 and the inclination of the evaporative cooling device 24 in the cover 22 promotes condensate drainage on the evaporator 24. A slot 156 in the rear of the cover 22 below the evaporator 24 in fig. 12 may direct water drained from the evaporator 24 for removal through a suitable drain line (not shown).

In all of the above arrangements, although it has been suggested to use a substantially horizontal top seal 60 between the bin 16 and the lid, it could be used in addition to or instead of a substantially vertical side seal. Fig. 13(a) and 13(b) illustrate an optimal method of making the side seal work effectively, wherein the cover 22 is fitted within the rim portion 158 of the case 16. As can be seen in fig. 13(a), the lid 22 tapers towards the front, the edge portion 158 of the box 16 being correspondingly shaped so that the box 16 can freely move away from the lid 22 when the corresponding drawer 4 is opened, and the lid 22 is squeezed within the tapered side of the peripheral portion 158 when the drawer 4 is closed. This forces the side seal 160 around the vertical outer side wall of the lid 22 or within the vertical inner side wall of the corresponding peripheral portion 158 to create a good seal between the lid 22 and the cabinet 16 when the drawer 4 is closed. As with the variation of FIG. 12, the seal is held in compression by a latch, hook or magnet (not shown) that prevents the case 16 from moving away from the lid 22 until access to the case 16 is desired.

Figures 14 and 15 show a variation of the apparatus in which a means is provided to remove ice or moisture from the exposed lower surface of the evaporative cooling means 24 within the cover 22. Such variations are not within the scope of the appended claims, but are included in the background.

The variation of fig. 14(a) and 14(b) uses a dual action scraper comprising a pair of parallel and oppositely angled blades 162 secured to a rear wall 164 of the housing 16, with each scraper edge appearing on the lower surface of the evaporator 24. Since the blades 162 are angled with respect to the lower surface of the evaporator 24, the rear blade 162 of the pair is able to remove ice and moisture from the evaporator 24 when the drawer 4 associated with the cabinet 16 is opened, and the front blade 162 of the pair is also able to remove ice and moisture from the evaporator 24 when the drawer 4 is closed. Ice or water droplets 166 scraped from the evaporator 24 fall into a drain pan 168 under the blade 162 and may be drained or left to melt and evaporate.

As in FIG. 14, another version of the scraper blade of FIG. 15 uses a drain pan 168 mounted to the rear wall 164 of the housing 16 to catch ice or water falling from the blade 162, which may also be secured to the rear wall 164 of the housing 16. Although a pair of blades 162 is used in fig. 14, a single blade 162 may be used. However, the variation of FIG. 15 differs fundamentally from the variation of FIG. 14 in that flexible membrane 170 is located immediately below the lower surface of evaporator 24, so that membrane 170 acts as a cooling interface between evaporator 24 and the interior of tank 16. The ice or water will therefore tend to collect on the membrane 170 rather than on the evaporator 24. Rollers 172 or other cross-bars, together with drain pan 168 and blade 162, are secured to rear wall 164 of cabinet 6 for movement with the moving drawer 4 and opposite blade 162. Roller 172 is supported at its ends and is positioned between evaporator 24 and film 170 so as to peel film 170 from evaporator 24, locally deforming film 170 in the region of blade 162. This promotes de-icing and moisture removal from the membrane 170 by flaking the ice and promoting the formation of water droplets that enter the drain pan 168.

If and when the apparatus disclosed in the background section of the above description should be defrosted, FIG. 16 shows how a defrost tray 174 is placed on top of the cabinet 16 to catch water dripping from the evaporator 24. The tray 174 includes a central recess 176 which is recessed within the open top of the housing 16 and surrounded by a peripheral edge 178 at the top of the wall of the housing 16 to support the load of the tray 174. It is envisaged that the tray 174 may be placed on top of the cabinet 16 in this manner when the associated drawer 4 is opened and the evaporator has been de-energised (preferably by a micro-switch sensing the action of opening the drawer 4 as described above), wherein the drawer 4 may be partially closed to the extent that it needs to be aligned with the tray 174 beneath the evaporator, but not just to activate the micro-switch and thereby re-switch on the evaporator 24. The turned off evaporator 24 slowly defrosts and the pan 174 catches the water droplets that are produced.

It will be noted from fig. 16 that the edge 178 at the rear of the defrost tray 174 extends rearwardly and is angled upwardly to define a scraper blade edge 180 adjacent the underside of the cover 22. The purpose of this feature is to scrape off moisture remaining on the underside of the evaporator 24 when the drawer 4 is opened after defrosting. The tray 174 may then be removed and the water in the recess 176 spilled.

Fig. 16 shows another finished absorbent pad 182 within the recess 176 of the defrost tray 124. The pad 182 absorbs free water in the recess 176 so that little water escapes when the tray 174 is removed. The pad 182 may be a heatable material to speed up the defrost process and may be preheated (preferably a microwave heating material) or heated instantaneously with electricity or other heating means.

Variations in cooling device and refrigerator engine arrangements and characteristics are also possible. For example, as shown in FIG. 17, the evaporator 24 on each cabinet 16 may be comprised of a fan coil unit that is supplied and evacuated of air by a remotely located fan coil unit in accordance with the present invention. Specifically, heat exchanger 184 is cooled by a cooling system 186 and absorbs heat from air circulated by a fan 188. The cool air discharged from the heat exchanger 184 is introduced into the closed casing 16, and the warm air is drawn out of the casing 16 by the fan 188, cooled by the heat exchanger 184, and circulated again. This is used in forced air flow refrigerators and so-called "frost free" freezers, which have the advantages of: most of the condensed water and ice can be treated outside the cooling compartment. For example, the heat exchanger 184 may employ an automatic defrost device wherein moisture drips into the drain pan 190 below the heat exchanger 184 when the heat exchanger 184 is periodically turned off. The features of the above-described variation, such as the doctor blade 162 and the defrost disk 174, may thus potentially be eliminated.

Although a single enclosure 16 is shown in FIG. 17 for clarity, fan coil cooling equipment may be used with multiple enclosures 16. The tanks 16 may be connected by a common conduit and use the same ventilation air, but due to cross contamination, each tank 16 preferably has a separate ventilation channel, although these may use a common heat exchanger. However, all of the separate flow channels will help to allow the temperature within each tank 16 to be independently controlled.

Fig. 18 and 19 show another variant according to the invention in which the tank 16 and its cover 22 are adapted to promote the drainage of the condensed water from the evaporator 24. To this end, as shown in fig. 19, the underside of the evaporator 24 is dished, defining a square central recessed area which houses a temperature sensor 192 surrounded by four facets 194 extending downwardly and outwardly at an inclination of approximately 5 degrees. The slope of the facets 194 is such as to direct the condensate on the evaporator 24 to drip outwardly under the force of gravity into a trough 196 (fig. 18) formed by a recess provided in the upper peripheral wall of the tank 16.

Fig. 18 shows that each trough 196 includes two angled portions 198, each leading down to a shared drain pipe 200 that communicates with an external drain pipe (not shown) through a J-bend in the wall of the tank 16.

In all of the above-described apparatus, viewing means may be provided to assist the user in viewing any of the articles within the bin 16 which are too high to be readily viewed from above through the open top of the bin. At its simplest, a window may be provided at the front and/or bottom of the enclosure 16. Another way to view the items is to place a mirror on the open enclosure 16 that is tilted to enable viewing from above the enclosure 16 even if the user's line of sight is below the mirror and possibly also below the enclosure 16. Preferably, the mirror is retractable when not in use, for example hinged to the front panel 52 of the refrigerator machine compartment 18-the mirror could even constitute the panel 52-or could be folded away from the front of the cabinet 16. Even if the bin 16 is raised just a little above the user's head, the benefit of viewing from above means that it is generally possible to reach deep into the bin 16 to access the desired item.

Many other variations are possible within the concept of the invention. For example, in addition to the vertically aligned drawers 4 common to the above-described apparatuses, drawers 4 arranged side by side may be used. Indeed, there may be any number of drawers from one up, and the drawers may be arranged as desired.

The configuration of the air gap 38 around the tank 16 may be varied without departing from the spirit of the present invention. Furthermore, the circulation of air inside the cabinet 6 may be facilitated in several ways.

Although the box 16 is preferably a large rectangle, which saves space, any polygon or circle, or even a hemisphere, may be used. Of course, the size and depth of the tank can vary widely within the concept of the invention.

The structure of the box 16 can also be varied: although a solid-walled tank 16 made of insulating material has been described, a vacuum design may also be used; i.e. using a double-walled tank, the two walls are separated by a partial vacuum or by only an insulating medium that entrains air.

Although a pull-out extended screen 70 is described in the above device, it is only one solution to provide a retractable screen. Other variations include a folded sheet in the shape of a hex-accordion when the drawer is closed, or a telescoping multi-layer sheet that can slide apart so that when the multi-layer sheet is pushed, the end of one sheet pushes the front of the next sheet.

Further, while the scraper 76 is a convenient method of removing condensate from the screen 70, other methods can be used. At its simplest, the water may be self draining from the screen 70 and will be collected in a suitably positioned tray.

In addition to providing a dedicated control and display panel 30 for each enclosure 16, all enclosures 16 may also be controlled by a single central control and display panel 30. Furthermore, while it is preferred that all of the enclosures 16 be individually controlled by a single shared panel 30 or by multiple dedicated panels 30, it is also possible within the contemplation of the present invention to predetermine the enclosure temperatures of a multi-enclosure device. The predetermined temperature may vary from case to provide different zones for storing different items. For example, while it is possible to keep changing the temperature range of a conventional refrigerator or freezer, one multi-compartment device can be designated as all refrigerators or all freezers if you like.

The present invention may be opened and closed using manual or automatic operation.

A partial vacuum may also be provided to the enclosed tank to eliminate oxygen and other gases and enzymes, thereby slowing product spoilage.

Accordingly, reference should be made to the following claims and other basic statements, rather than to the foregoing detailed description, as indicating the scope of the invention. In understanding the present invention, it is to be understood that although features of the described embodiments have been described in conjunction with each other, such a combination, while having its own advantages, may provide many of the advantages thereof on its own. Thus, such features are regarded as being patentable independently, whether or not they are included in or outside the inventive concepts expressed herein.

Claims (73)

1. A refrigerator and/or freezer apparatus suitable for domestic, industrial, scientific or medical use, comprising:

at least one drawer comprising an open-topped insulated container having an outer surface;

an insulating cover adapted to close the open top of the container;

a seal sealing the container and the lid when the container is closed;

a cooling device adapted to cool the interior of the container but not the exterior, the cooling device comprising a heat exchanger associated with the lid or a cold air duct associated with the lid, the cold air duct feeding cold air to the container when the container is closed; and

a structure supporting the drawer, the cover and the cooling device;

wherein the drawer is mounted on the structure and is movable relative to the structure and the lid to open the container and provide access to the container interior or to close the container;

at least a majority of the exterior surface of the container is exposed to ambient air when the container is closed by the lid; and

when the cooling means comprise a heat exchanger associated with the cover, the heat exchanger is generally inclined, or has a partially inclined portion, so as to promote the evacuation of the moisture condensed on the heat exchanger from the interior of the container, and the heat exchanger communicates with a duct in the cover or in the container for evacuating the moisture from the heat exchanger.

2. The apparatus of claim 1, wherein movement of the drawer relative to the structure and the lid includes a primarily horizontal component of movement.

3. The apparatus of claim 2, wherein the drawer is mounted to the structure by means for movement along at least one horizontal track.

4. The apparatus of claim 3, wherein the track comprises at least one guide rail.

5. Apparatus as claimed in claim 4, wherein the or each guide is sleeve-shaped.

6. The apparatus of claim 2, wherein the drawer is supported by wheels or rollers that move along a horizontal support surface.

7. The appliance of claim 2, wherein horizontal movement of the drawer is achieved by opening a door of the appliance.

8. The apparatus of claim 1 wherein the movement of the drawer relative to the structure and the lid includes a vertical minor component of movement, wherein the drawer is mounted on the structure by means permitting said generally vertical movement.

9. The appliance of claim 8, wherein the container is raised toward the lid when closed and lowered away from the lid when open.

10. The apparatus of claim 8 further comprising a rail or support surface comprising a ramp that effects said vertical component of movement.

11. Apparatus according to claim 8, including crank means responsive to closure of the container to raise the drawer towards the lid.

12. The appliance of claim 1, wherein closing movement of the drawer relative to the structure and the lid wedges the container and the lid together.

13. The apparatus of claim 12, wherein a rail or support surface supporting the drawer is wedged within the lid in the closing direction of the drawer.

14. The apparatus of claim 12, wherein the lid is received and encompassed by an edge portion of the container, the lid being laterally compressed when the container and the lid are wedged together.

15. The apparatus of claim 14, wherein the cover and the rim portion are all tapered complementary.

16. Apparatus according to claim 12, comprising support means for supporting the container wedged against the lid.

17. The apparatus of claim 3, wherein the rail or support surface is exposed to ambient air.

18. The apparatus of claim 1, wherein the seal is compressible.

19. The apparatus of claim 1, wherein the seal is a magnetic, hydraulic or pneumatic type seal.

20. The apparatus of claim 19, wherein the magnetic seal is an electromagnetic seal.

21. The apparatus of claim 1, wherein the opening movement of the drawer is against gravity.

22. The appliance of claim 1, wherein substantially all of the external surface of the container is exposed to ambient air when the container is closed.

23. The apparatus of claim 1, wherein the outer surface of the container comprises a plurality of surface portions.

24. The appliance of claim 23, wherein the surface portion of the container is defined by the bottom and side walls of the container.

25. The apparatus of claim 1, wherein the container is generally cubic.

26. The appliance of claim 1, further comprising a scraper or cleaner arrangement associated with the drawer to remove ice or water from the cooling arrangement based on relative movement between the lid and drawer.

27. The appliance of claim 26, further comprising first and second scraper or cleaner blades respectively provided for removing ice or water from the cooling means during the drawer opening and closing movement.

28. The appliance of claim 1, further comprising a flexible membrane associated with the cooling means and means for locally deforming the membrane for relative movement between the drawer and lid to remove ice or water from the membrane.

29. The apparatus of claim 1, wherein the cooling device is integral with the lid.

30. The apparatus of claim 1, wherein the cooling device is a heat exchanger substantially flush with the underside of the lid.

31. The apparatus of claim 1, further comprising a shut-off device that shuts off the cooling device when the container is not closed.

32. The appliance of claim 31, wherein the closure means comprises a closure means closed by the presence of a container.

33. The appliance of claim 1, wherein a retractable screen is extendable to shield the cooling means when the container is opened.

34. The apparatus of claim 33, wherein the screen is connected to the structure at one end and to the vessel or to a device associated with the vessel at the other end.

35. The apparatus of claim 33, wherein the screen is removably attached to the device associated with the container.

36. The apparatus of claim 35, further comprising a retaining device for retaining the screen in a fully or partially extended configuration when the screen is disengaged from the receptacle.

37. The apparatus of claim 33, wherein the screen is exposed to ambient air when retracted.

38. The apparatus of claim 33, wherein the screen is wound on a roller when retracted.

39. The apparatus of claim 33, wherein the screen is heat reflective.

40. The apparatus of claim 33 wherein the cleaner or scraper is operable to remove water and ice from the screen during retraction of the screen.

41. The apparatus of claim 33, wherein the screen is biased into a retracted configuration.

42. The apparatus of claim 1, wherein the cooling device is adjustable so that the same container can be used for both refrigeration and freezing.

43. The apparatus of claim 1, wherein the structure is a cabinet.

44. The apparatus of claim 1, wherein the structure is a frame.

45. The apparatus of claim 44 wherein the frame is adapted to be built between cabinets or other structures.

46. The apparatus of claim 1 wherein the structure defines at least one ambient air circulation channel around the exterior surface of the enclosed container.

47. The apparatus of claim 1, further comprising means for drawing ambient air from the front of the apparatus.

48. The apparatus of claim 47 wherein the structure defines a front panel including at least one opening for entry of ambient air.

49. The apparatus of claim 48, wherein the front panel further comprises a control and/or display device.

50. The apparatus of claim 1, further comprising means for exhausting ambient air to a front of the apparatus.

51. The apparatus of claim 1, further comprising an impeller to facilitate intake and exhaust of ambient air.

52. The apparatus of claim 1, wherein the container is detachable from the structure.

53. The appliance of claim 52, wherein an auxiliary lid is attached to the container when the container is detached from the structure.

54. The appliance of claim 52, wherein a retrievable screen is extendable to shield the cooling means when the container is open, the screen being connected at one end to the structure and at the other end to a moveable tray adapted to receive the container.

55. The appliance of claim 1, wherein the drawer is movable in a plurality of different directions relative to the structure to open the container.

56. The apparatus of claim 1, further comprising means for partitioning the interior of the vessel.

57. The apparatus of claim 1, wherein the apparatus has a plurality of containers, each of said containers having a respective cooling means, each cooling means being independently controllable.

58. The appliance of claim 57, wherein the cooling means is connected to a common refrigerator motor.

59. The apparatus of claim 1, wherein the apparatus has a plurality of containers stacked one on top of the other.

60. The apparatus of claim 1, wherein the apparatus has a plurality of containers, and further comprising means for preventing the opening of a container when another container of the plurality of containers is opened.

61. The apparatus of claim 1, wherein the apparatus has a plurality of containers having different internal sizes, shapes or volumes.

62. The apparatus of claim 1, further comprising viewing means to assist a user in viewing the contents of the container.

63. The appliance of claim 62, wherein a viewing window is provided in the front and/or bottom of the container.

64. The appliance of claim 62, further comprising a sight glass positioned above the container for reflectively viewing the open top thereof from above the container.

65. The apparatus of claim 64 wherein the mirror can be retracted when not in use.

66. The apparatus of claim 65, wherein the mirror is attached to the container.

67. The apparatus of claim 64 wherein the mirror is positioned above the containers for viewing the contents of any of the containers.

68. The apparatus of claim 1, further comprising a defrost tray positioned below the in-tank cooling device.

69. The apparatus of claim 68 wherein the defrost tray includes a scraper and cleaner arrangement to remove ice or water from the cooling arrangement based on relative movement of the drawer and the lid.

70. The apparatus of claim 68 wherein the defrost tray includes an absorbent insert.

71. The apparatus of claim 70, wherein the insert is heatable.

72. The apparatus of claim 1, wherein the cooling device comprises a heat exchanger that is an evaporator exposed to the interior of the container when the container is closed.

73. The apparatus of claim 1 wherein the cooling device comprises a cold air duct that inputs cold air supplied by a fan coil circuit.