GB2367353A - Improvements in or relating to cold storage - Google Patents

Abstract

A cold storage appliance includes an open-topped container (16), a lid (22) adapted to close the container, a structure supporting the container and lid in the appliance, the container being mounted to the structure for movement relative to the structure and the lid to open or close the container, the lid being mounted to the structure for movement relative to the structure and the container to free the container from the lid upon opening or to bring the container and the lid together upon closing. The lid may be connected to a counterbalance weight (72). Means may be provided to move the container directly away from the lid, upon the initial pull on the container when moving the container out of the appliance, or directly towards the lid, upon the final push on the container when moving the container into the appliance. The lid (22) includes an evaporator on the internal surface of the lid. The external surface of the container may be exposed to air above ambient temperature when the container is closed by the lid. Should the containers be stacked together, the container may include external formations which define airflow channels. A container may include a bellows arrangement attached to the rear of the container. The formations may be in the cover of the container. The appliance may include a relatively large capacity compressor and a relatively small capacity compressor to handle the varying cooling demands. The cooling means for the appliance may be adjustable to maintain the temperatures within a container either side of zero Celsius to selectably freeze or chill the contents placed therein. A vehicle mounted freight container may have an open top, closed by a removable cover. A crane may be provided to access the open top.

Description

IMPROVEMENTS IN OR RELATING TO COLD STORAGE The inventions herein relate to the art of cold storage, including appliances such as refrigerators and freezers for storing foodstuffs and other perishables. Other applications of the inventions include storage of chemicals and medical or biological specimens. The inventions also find use in mobile applications, for example in the bulk transport and storage of perishable goods.

The inventions develop and add to the various features of the Inventor's co-pending International Patent Application No. PCT/GBOO/03521, the contents of which are incorporated herein by reference. As in that specification, the inventions can be applied to storing any items within a cooled environment, such as in a refrigerated goods vehicle.

The term'appliance'is therefore to be construed broadly, extending beyond fixed domestic devices into industrial, scientific and mobile applications. Whilst further reference will be made to mobile applications for the bulk transport and storage of perishable goods, the majority of this specification will again describe domestic or commercial cold-storage appliances for storing foodstuffs.

Briefly to recap the introduction of PCT/GBOO/03521, the advantages of storing foodstuffs and other perishable items in refrigerated and segregated conditions have long been known: refrigeration retards the degradation of such items and segregation helps to prevent their cross-contamination. Accordingly, modem cold-storage appliances such as refrigerators and freezers are usually compartmentalised, albeit not often effectively, so that a user can store different types of food in different compartments. All such appliances have the additional aim of maximising their energy efficiency.

The inventions herein and the inventions in PCT/GBOO/03521 were devised against a background of typical cold-storage appliances, most of which comprise one or more upright cabinets each with a vertically-sealed hinged door on its front. Substantially all of the interior of the cabinet defines a storage volume, most commonly partitioned by shelves or drawers for supporting stored foodstuffs. Access to all of the shelves or drawers in the cabinet is gained by opening the door.

A cooler unit generates a convection loop within the cabinet, in which air cooled by the cooler unit sinks toward the bottom of the cabinet and as that air absorbs heat during its downward journey, it warms and rises back up to the cooler unit where it is cooled again. It is also possible to have forced-air circulation by means of a fan within or communicating with the cabinet. The shelves or drawers are typically made of wire so that they offer little resistance to this circulation of air.

Upright refrigerators and freezers are often combined and sold as a single-cabinet'fridge freezer'unit with a refrigerator occupying an upper compartment and the freezer occupying a lower compartment, or vice versa. As different temperatures are required for the two compartments, they are partitioned by a solid divide and each compartment has its own door and cooler unit, conventionally in the form of an evaporator.

The domestic fridge freezer usually has only one compressor and the refrigerator evaporator is in series with the freezer evaporator. In that case, temperature control and measurement is usually confined to the refrigerator compartment. Where temperature control is required in both compartments, the evaporators are in parallel and have respective solenoid valves and temperature switches providing on/off cooling mass control to each compartment. In either case, however, the temperature within the respective compartments cannot be duplicated: one compartment is for chilling, so it has less insulation than the other and its temperature can be adjusted within a range above zero Celsius, and the other is for freezing, so it has more insulation than the other and its temperature can be adjusted (if at all) within a range below zero Celsius. Neither compartment can do the job of the other.

Like the present inventions, PCT/OBOO/03521 addresses a major problem with upright refrigerators and freezers, namely the upright door which, when opened, allows cold air to flow freely out of the cabinet to be replaced by warm ambient air flowing in at the top.

That rush of ambient air into the cabinet causes its internal temperature to rise, hence consuming more energy in redressing that rise by running the cooler unit. The incoming ambient air introduces the possibility of airborne contamination, and moisture in that air also gives rise to condensation and ice within the cabinet. The more often and frequently

the cabinet is opened, as may happen especially in commercial cold storage appliances, the worse these problems get. In upright-door arrangements, the limitations of the vertical seal mean that loss of cold air and induction of warm air can even occur when the door is closed. Being denser than warmer air, the coldest air collects at the bottom of the cabinet and applies pressure to the sealing interface so that unless the seal forms a perfect seal between the door and the cabinet, that air will escape.

The present inventions and PCT/GBOO/03521 also address the problems inherent in the well-known chest freezer, whose open-topped cabinet is typically closed by a horizontallyhinged upwardly-opening lid. Such a chest freezer is inconvenient and wasteful of space because it precludes use of the space immediately above the freezer, which space must be preserved to allow its lid to be opened. Even if a sliding lid is used instead of an upwardlyopening lid, items cannot be left conveniently on top of the lid. It is also well known that large chest freezers can make access to their contents extremely difficult, it being necessary to stoop down and shift numerous heavy and painfully cold items to get to items at the bottom of the freezer compartment.

Finally, the present inventions and PCT/GBOO/03521 address the problem of segregating different types of foodstuff or other perishable items to avoid cross-contamination. In typical cold-storage appliances, segregation of food is compromised by the convection and/or forced-air principles on which those appliances rely. The substantially open baskets or shelves designed to promote convective circulation of air between the compartments also promote the circulation of moisture, enzymes and harmful bacteria. In addition, any liquid that may spill or leak, such as juices running from uncooked meats, will not be contained by the open baskets or shelves.

Conventional cold-storage appliances exemplified by upright refrigerators and chest freezers are not the only prior art disclosures of interest. For example, it has been known for many years to divide a refrigerator into compartments, each with its own dedicated door or lid. Examples of this idea are disclosed in UK Patent Nos. GB 602,590, GB

581, 121 and GB 579, 071, all to Earle, that describe cabinet-like refrigerators.

In those Earle documents, the front of the cabinet is provided with a plurality of rectangular openings for receiving drawers. Each drawer has a front panel larger than its respective opening so that a vertical seal is formed around the overlap when the drawer is in a closed position. The drawers and their contents are cooled by a cooler unit that circulates cooled air by convection within the cabinet, in common with the types of refrigerator already described. To promote circulation of this air amongst all of the drawers, the drawers are open-topped and have apertures in their bottoms. Also, the drawers are disposed in a stepped arrangement, those at the top of the refrigerator extending back less far into the cabinet than the lower drawers so that the rear of each drawer is exposed to the downward flow of cooled air from the cooler unit.

Although only one drawer need be opened at a time, the apertures in the bottom allow cold air to flow freely from the open drawer, which is replaced by warm moist ambient air to the detriment of energy efficiency and with the increased possibility of crosscontamination. Indeed, when a drawer is opened, cold air within the cabinet above the level of that drawer will flood out, drawing ambient air into the cabinet. Furthermore, the drawers encourage ambient air to flow into the interior of the refrigerator because, upon opening, they act as pistons drawing the ambient air into the interior of the refrigerator cabinet. Once in the cabinet, the warm air can circulate as freely as the cold air that is supposed to be there.

Even when closed, the accumulation of cold air towards the bottom of the cabinet will exert increased pressure on the vertical seals of the lowest drawers, increasing the likelihood of leakage if the seal is faulty.

A further example of the above type of refrigerator is disclosed in UK Patent No.

GB 602,329, also to Earle. The refrigerator disclosed therein suffers many of the above problems but is of greater interest in that a single drawer consisting of insulated sides and base is provided within the cooled interior of the cabinet. In contrast to the variants outlined above, the sides and base are solid and not perforated so that air cannot flow

through them. When the drawer is closed, a horizontal member within the cabinet combines with the drawer to define a compartment, the horizontal member thus being a lid for the drawer. This compartment is provided with its own cooling coils situated just below the horizontal member.

Very little detail is given about the seal that is formed between the drawer and the horizontal member, other than that the horizontal member has a downwardly projecting rear end with a biased edge that makes a close fit with the rear wall of the drawer. Nothing else is said about the junction between the drawer and the horizontal member, apart from the general statement that the drawer is adapted when in its closed position to fit'fairly snugly'against the horizontal member. It can only be inferred that the drawer and the horizontal member merely abut against each other. Whilst this will impede the passage of air into and out of the drawer, it will not form an impervious seal. As this is not a vapour seal, icing and cross-contamination is likely to occur even when the drawer is closed.

The drawer arrangement described creates a compartment in which a different temperature can be set when compared to the essentially common temperature of the rest of the refrigerator. It is particularly envisaged that the drawer can act as a freezer compartment.

The Applicant has appreciated a disadvantage in this arrangement, namely that as the freezer drawer resides within the cooled interior when closed, the outer surfaces of the drawer within the cabinet will be cooled to the temperature of the refrigerator.

Accordingly, when the drawer is opened, those cooled outer surfaces will be exposed to ambient air containing moisture that will condense on the cooled surfaces leading to an undesirable accumulation of moisture. Condensation involves transfer of latent heat from water vapour to the drawer, thus increasing the burden of cooling the drawer again when the drawer is returned to the closed position within the cabinet.

Additionally, condensed moisture will be transferred to the interior of the refrigerator when the drawer is closed. As discussed above, the presence of water promotes microbial activity. A further disadvantage of introducing water into the interior of the refrigerator is that it may freeze: this can be a particular problem where the drawer of the enclosed compartment meets the insulated top, as any ice formation will form a seal that locks the

drawer in a permanently closed position. In fact, the bulk of ice formation is due to moisture migration across the interface between the drawer and the top. This disadvantage was appreciated by Earle, as a cam mechanism is mentioned in GB 602,329 to break any ice formed at the seals or on the runners or other support surfaces of the drawers. It is also possible for a build-up of ice to affect the sealing ability of the seal, by preventing mating sealing surfaces from mating correctly. Of course, the accumulation of ice on moving parts of the drawer mechanism is also undesirable as it will impede movement of the drawer.

A further interesting prior art document, cited as technological background against PCT/GBOO/03521, is US Patent No. 1,337, 696 to Ewen. Ewen speaks of segregation between refrigerated drawers contained in a surrounding cabinet and employs refrigerating units placed'immediately and closely above each drawer... so that said drawer may in effect be said to be closed against said refrigerating unit'. However, there has to be a gap left between the drawer and the refrigerating unit if the drawer is going to open. As in Earle, that gap will promote icing as moist air within the cabinet migrates into the drawer and the water vapour condenses and freezes. The smaller the gap, the sooner the accumulating ice will prevent drawer movement. If a larger gap is tried instead, there will be a greater spillage of air and hence the refrigerator will be less energy-efficient and more susceptible to cross-contamination.

That aside, the spillage of cold air in Ewen lowers the temperature within the cabinet around the drawers, and so increases the likelihood of condensation on the drawers when opened. It will be noted that cold air spilled in this way can fall freely behind the drawers within the cabinet and so expose the exterior of the drawers to air substantially below ambient temperature. Certain design details of Ewen worsen this effect. For example, the bottom wall of the Ewen unit is an efficient insulator which will significantly reduce the surface temperature of the drawers. Also, the internal divisions between the drawers do not allow for ambient heat transfer to the drawers but only for heat transfer between the drawers, thus promoting drawer-to-drawer temperature equalisation over time. Left for long periods, or even overnight, large parts of the external surface of each drawer will fall to temperatures significantly below ambient dew point. Condensation or ice will therefore form on those surfaces as soon as the drawers are opened; similarly, if the drawers are

removed and left outside the appliance, they will start to'sweat'with condensation. Like Earle, opening and closing a drawer within a sealed cabinet in Ewen acts like a piston, alternately applying both negative and positive pressures to adjacent areas. This promotes air transfer through the drawer opening at the front of the cabinet, which can displace cold treated air in a drawer, and within the cabinet itself. An over-sized cabinet would reduce the piston effect but would also be wasteful of space. Conversely, a more space-efficient close-fitting cabinet may decrease the displacement of cold treated air, and so reduce the burden of cooling the warmer air that takes its place, but it will increase resistance to opening and closing the drawer.

Cold air spillage aside, the gap inevitably left between a drawer and its associated lid in prior art arrangements is large enough to allow the passage of enzymes, spores and other airborne contaminants. Also, Ewen discloses a common interconnecting drain and this too would allow free transfer of contaminants between each drawer, particularly under the aforementioned piston action.

Whilst Ewen speaks of different temperatures in different drawers, the plurality of cooling lids are connected in series and have no means for individual temperature control in each drawer. The different temperatures are designed-in by providing some drawers with more cooling elements than others, but there is no measurement or control of those temperatures in use. Also, like the compartments of more conventional prior art, each drawer in Ewen has a fixed function, namely freezer or refrigerator.

Even if removed from the appliance, Ewen's drawers will stay attached to their drawer fronts and runners. This does not lend the drawers to temporary storage or transport. Moreover, like Earle, the drawers in Ewen cannot be opened fully : they can only be opened less than half-way while being supported by the structure of the appliance. This is to the detriment of access to, and visibility and illumination of, the contents.

It is against this background that the present inventions have been devised.

From one aspect, the invention resides in a cold-storage appliance including : an opentopped insulating container defining an external surface ; an insulating lid adapted to close the open top of the container; a cooling means adapted to cool the interior of the container; and a structure supporting the container, the lid and the cooling means; wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afford access to its interior or to close the container, and wherein the lid is mounted to the structure for movement relative to the structure and the container to free the container from the lid upon opening or to bring the container and the lid together upon closing.

Thus, in this aspect of the invention, the lid moves to free the container for movement. In a simple arrangement that will be described, the lid can be tilted relative to the structure and the container. For example, the lid can be hinged to the structure, the hinge preferably defining a pivot axis horizontally spaced from the container so that the lid is lifted fully away from the container. More generally, it is preferred that the lid is movable transverse to the direction of movement of the container.

Beneficially, lid transport means are responsive to movement of the container or of a support means movable to support the container during said movement. The lid transport means can move the lid before the container starts moving upon opening and after the container has stopped moving upon closing. In that case, where a support means is movable to support the container during said movement, the lid transport means is preferably between the support means and the lid and responds to movement of the support means to move the lid.

The support means can be movable independently of the container, in which case the lid transport means can be responsive to relative movement between the support means and the container and more particularly to continued movement of the support means after movement of the container has ceased.

In an alternative arrangement, the lid transport means moves the lid during initial movement of the container upon opening and during final movement of the container upon closing.

The invention also resides in a cold-storage appliance including: an open-topped insulating container defining an external surface; an insulating lid adapted to close the open top of the container; a cooling means adapted to cool the interior of the container ; and a structure supporting the container, the lid and the cooling means; wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afford access to its interior or to close the container, and wherein said movement of the container includes: a major component to open the container and afford access to its interior or to close the container; and a minor component, transverse to the major component, to free the container from the lid at the beginning of said major component upon opening or to bring the container and the lid together at the end of said major component upon closing.

In this aspect of the invention, the two-component movement of the container serves to clear the container from the lid. To avoid a wiping action on seals between the container and the lid, it is preferred that the minor component takes place before the major component upon opening and after the major component upon closing. However, it is also possible for the minor component to take place during initial movement in the direction of the major component upon opening and during final movement in the direction of the major component upon closing.

In this aspect, it is preferred that a support means is movable to support the container during the major component and that container transport means is disposed between the support means and the container to responds to movement of the support means to effect the minor component. Where the support means is movable independently of the container, the container transport means can be responsive to relative movement between the support means and the container. For instance, the container transport means is preferably responsive to continued movement of the support means after the major component of movement of the container has been completed.

The container transport means suitably includes a first part in fixed relation to the support means and a second part in fixed relation to the container, wherein relative movement between the parts accommodates said continued movement of the support means. In this case, relative movement between the parts causes the minor component of movement of the container. For example, one part can include a ramp and the other part can include a ramp follower, such as a wheel. The ramp may further be associated with stops or buffers to limit relative movement of the ramp follower.

Advantageously, the support means may also be fixed to a stabilising mechanism to resist lateral sway of the container during the major component of movement. That stabilising mechanism preferably includes pinions movable with the support means, the pinions being engaged with respective laterally-spaced racks extending in the direction of the major component.

In another aspect, the invention resides in a cold-storage appliance including: an opentopped insulating container defining an external surface; an insulating lid adapted to close the open top of the container; a cooling means adapted to cool the interior of the container; and a structure supporting the container, the lid and the cooling means; wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afford access to its interior or to close the container, and wherein the external surface of the container is exposed to air above ambient temperature when the container is closed by the lid. This aspect of the invention further reduces icing and condensation associated with the exterior of the container.

The aforesaid containers can preferably be removed from the appliance of the invention. A related aspect of the invention resides in a cold-storage container adapted to be stacked or otherwise grouped with other abutting containers, wherein the container has external formations shaped to define airflow channels around at least part of the container when the container is in such a group of abutting containers. This avoids or minimises insulation traps.

For example, some or all of the formations can be defined by a cover of the container. The formations can include ribs or castellations, or other combinations of projections and/or recesses on external surfaces of the container and/or the cover.

The container or its cover preferably has a part projecting sideways to abut a neighbouring container or a cover of such a container in a group. The abutting projecting part can then define an airflow channel between opposed side walls and/or covers of the neighbouring containers.

Advantageously, the covers of neighbouring containers co-operate to define a substantially flat and continuous support surface penetrated by airflow channels. In that event, where the cover overhangs at least one side wall of the container to serve as the abutting projecting part, airflow channels preferably penetrate the support surface and communicate with an airflow channel defined by the overhanging cover between opposed side walls of the neighbouring containers.

A further aspect of the invention resides in a cold-storage appliance including a plurality of containers cooled by forced air cooling means and comprising a corresponding plurality of air circulation paths, one for each container, wherein the air circulation paths are segregated and vapour-sealed from each other but a common cooling means is shared by the air circulation paths.

This aspect of the invention provides for segregation between the air circulation paths, beneficially minimising cross-contamination, but with a compact and cost-effective construction. Nevertheless separate defrost and drainage means, one for each air circulation path, are preferably associated with the common cooling means in each air circulation path. This further minimises the risk of cross-contamination.

Beneficially, the air circulation paths are defined by ducts separated from one another by an insulating gap, which gap may be filled by air or an insulating material. In that event, the aforementioned drainage means neatly comprises a drainage duct that runs through the insulating gap between air circulation paths.

A still further aspect of the invention resides in a cold-storage appliance including a major compressor and a minor compressor and switch or valve means responsive to cooling demands upon the appliance for switching cooling load between the compressors, such that the major compressor handles relatively high cooling demands and the minor compressor handles relatively low cooling demands. The compressors can work separately or alternately, but it is preferred that the major compressor and the minor compressor together handle relatively high cooling demands. Those compressors are preferably disposed in parallel.

The invention also resides in a cold-storage appliance including: at least one container; a structure defining a vapour-sealable container compartment from which the container can be withdrawn to open the container and afford access to its interior and to which the container can be returned to close the container for cold storage of any items within the container; and valve means communicating with the container compartment to admit air from outside the appliance when the container is being withdrawn from the container compartment, to expel air outside the appliance when the container is being returned to the container compartment, and to maintain a vapour seal with the container compartment when the container is within the container compartment. This mitigates the piston effect which could otherwise promote cross-contamination between containers in a multicontainer arrangement.

The invention may also be expressed in terms of a cold-storage appliance including: at least one container; a structure defining a vapour-sealable container compartment from which the container can be withdrawn to open the container and afford access to its interior and to which the container can be returned to close the container for cold storage of any items within the container; and barrier means adapted to advance and to retract along the container compartment as the container is being withdrawn from and returned to the container compartment, while maintaining a vapour seal so as (i) to separate from the interior of the container air drawn into the container compartment by withdrawal of the container and (ii) to displace that air from the container compartment when the container is returned to the container compartment. This also mitigates the piston effect and its risk

of cross-contamination by maintaining a vapour seal between the interior of the container and air within the compartment vacated by the container. For example, the barrier means can be a bellows extensible along and sealed to the surrounding walls of the container compartment.

Moving on to aspects of the invention relating to bulk storage and transport of items, the invention contemplates a vehicle-mountable freight container for transporting or storing bulk perishable items, the container having insulating walls defining an open top ; and an insulating cover adapted to close the open top and being movable or removable to afford access from above the container to its interior for loading or unloading the bulk perishable items. The container may further comprise a cooling means adapted to cool the interior of the container, which cooling means suitably includes a refrigerator engine mounted to a side or end of the container so as to leave the top of the container clear for stacking.

The cooling means advantageously includes a refrigerator engine that is removable from the container in modular fashion. Where the container has a removable cover, the refrigerator engine is, elegantly, removable as a module with the removable cover.

The container of the invention may further comprise an upwardly-facing seal around the open top of the container, to create a vapour seal with a suitably-equipped handling facility. For the purposes of employing such a handling facility and effecting a seal with the open top of the container, the invention extends to a vehicle for transporting or storing bulk perishable items in the vehicle-mountable freight container of the invention and having means for adjusting the height of the open top of the container relative to the ground supporting the vehicle.

The refrigerated handling facility contemplated by the invention comprises a downwardlyopening hatch co-operable with the open top of the container of the invention. That hatch is preferably defined in a structure overhanging a loading bay capable of receiving a vehicle carrying the container. A hoist may be provided for removing the cover of the container before the vehicle enters the loading bay with the open-topped container.

Advantageously, to minimise loss of cold air and the risk of cross-contamination, the handling facility of the invention further includes a downwardly-facing seal around the hatch that is co-operable with the container around its open top, and may also include a hatch cover movable to close the hatch. To effect that seal, means may be provided below the hatch for raising or lowering a vehicle or container beneath the hatch.

A crane is preferably movable over the open hatch to access the interior of an open-topped container below the hatch.

The invention extends to the related system for transporting or storing bulk perishable items, comprising a handling facility as defined above in combination with a container as defined above and/or a vehicle as defined above.

The invention may also be expressed in method terms as: a method of handling bulk perishable items, comprising storing those items in open-topped insulated freight containers within a refrigerated storage facility and subsequently transporting the containers after attaching or closing an insulated cover to close the open top; or a method of handling bulk perishable items, comprising transporting those items in open-topped insulated freight containers having an insulated cover to close the open top, opening or removing the cover to open the top, and accessing the interior of the open-topped container from above to load and/or unload the items from the container. The method suitably comprises moving the open-topped container under a downwardly-opening hatch leading to a refrigerated handling facility, and loading and/or unloading the items through the hatch, and may further comprise sealing around the container and the hatch.

Finally, for optimum flexibility, the invention contemplates a cold-storage appliance including at least one container and a cooling means adapted to cool the interior of the container, wherein the cooling means is adjustable to maintain temperatures within the container either side of zero Celsius, selectably to freeze or to chill contents placed therein. This aspect of the invention see most benefit where the appliance includes a plurality of containers and said cooling means are independently controllable such that different temperatures can be selected in different containers. Thus, for example, there

may be means for selectably designating each container as either a chiller or a freezer to vary the ratio of chilled to frozen storage space in the appliance. In order that the present inventions can be more readily understood, reference will now be made, by way of example only, to the accompanying drawings in which: Figure 1 is a front view of a refrigerator/freezer appliance as disclosed in the Applicant's co-pending International Patent Application No. PCT/GBOO/03521, showing a vertical array of drawers each including a bin; Figure 2 is a side view of the appliance of Figure 1, with a lower portion of a side panel removed so that the sides of the drawers can be seen; Figure 3 is a section along line m-ici of Figure 2 but with the drawers closed; Figure 4 is a section along line IV-IV of Figure 1; Figure 5 is an enlarged schematic sectional side view of two drawers of an appliance of the invention in which a lid is movable with respect to the structure to separate the lid from a bin, thereby allowing the bin to be moved subsequently in a single opening direction; Figures 6 (a) and 6 (b) are partial sectional side views of an appliance in accordance with the invention, Figure 6 (a) showing a drawer closed with its bin sealed to a lid, and Figure 6 (b) showing (in solid lines) the drawer partially open with the bin dropped vertically away from the lid, and then (in dashed lines) fully open with the bin slid horizontally forward to afford access to its interior ; Figure 7 is a front part-sectional detail view of a bin transport mechanism being part of the appliance of Figures 6 (a) and 6 (b); Figure 8 is a partial side view of a bin being part of the appliance of Figures 6 (a),

6 (b) and 7 ; Figure 9 is detail side view of a wheel housing shown in Figures 6 (a), 6 (b) and 7 ; Figures 10 (a) and 10 (b) are schematic detail side views of the wheel housing of Figure 9 in operation; Figures l1 (a) and ll (b) are side views of a drawer in accordance with the invention, which is akin to that shown in Figures 6 (a) and 6 (b) but has the added refinement of a lever that assists opening and closing of the drawer; Figure 12 is a schematic plan view within a drawer recess of an appliance adapted to receive a drawer of Figures 6 (a) and 6 (b) or Figures I I (a) and I I (b); Figures 13 (a), 13 (b) and 13 (c) are schematic plan, side and sectional views respectively of a bin removed from the appliance and fitted with a transport cover; Figures 14 (a) and 14 (b) are side elevation and plan views respectively of a group of bins when removed from a cold-storage appliance, each bin being fitted with a transport cover as depicted in Figures 13 (a), 13 (b) and 13 (c) and each covered bin being arrange to co-operate with neighbouring covered bins in the stack to define airflow channels between them; Figure 15 is a side elevation that broadly corresponds to Figure 14 (a) but shows stacked covered containers each having a respective refrigerator engine, and an enlarged air gap between the containers; Figure 16 is a side elevation that broadly corresponds to Figure 15 but shows densely-stacked covered containers each having a respective refrigerator engine connected to services being a mains power supply and an auxiliary water-cooled condenser;

Figure 17 is a plan view into the top of an open storage bin ; Figures 18 (a) and 18 (b) are a plan view and a sectional side view respectively of a lid showing its sealing, cooling and drainage facilities in detail; Figure 19 is a diagrammatic view of a plurality of the lids of Figures 18 (a) and 18 (b), showing their separate drainage arrangements; Figures 20 (a) and 20 (b) are a bottom plan view and a sectional side view respectively of a lid adapted for use in a fan coil cooling system; Figure 21 is a diagrammatic view of a fan coil cooling system having multiple segregated air circulation paths; Figures 22 (a) and 22 (b) are a sectional plan view and a sectional side view respectively of a fan coil cooling unit package being a compact practical embodiment of the principles shown in Figure 21 ; Figure 23 is a general system arrangement diagram of a cold store appliance of the invention having four drawers/evaporators and a hot-gas defrost facility; Figure 24 is a symbols key and table of notes to be read in conjunction with Figure 23; Figures 25 (a), 25 (b) and 25 (c) are front and side elevation views and an enlarged partial cross-sectional detail view of a bench-type cold-storage appliance having an alternative layout to that shown in Figures 1 to 4; Figures 26 (a) and 26 (b) are side elevation views of a height-adjustable castor that can be used with any of the appliances of the invention; Figures 27 (a), 27 (b) and 27 (c) correspond to Figures 20 (a), 20 (b) and 20 (c) of

PCT/GBOO/03521 and are schematic views of a scaled-up extension of the inventive concept, being applied to bulk storage in a cold store and commercial transportation in a refrigerated vehicle; Figure 28 is a schematic sectional side view of the interior of a container shown on a truck in Figure 27 (a); Figure 29 is a schematic sectional side view of an alternative container arrangement better suited to stacking; Figures 30 (a), 30 (b) and 30 (c) are schematic side views of the truck of Figure 27 (a) being loaded or unloaded at a cold-storage facility; Figures 31 (a), 31 (b) and 31 (c) are a front elevation and two sectional views respectively of a cold-storage appliance that is functionally akin to the aforementioned Ewen prior art but addresses many of its problems; Figures 32 (a), 32 (b), and 32 (c) are partial sectional side views showing various ways of preventing temperature gradients within each compartment of the appliance of Figures 31 (a), 31 (b) and 31 (c); Figures 33 (a), 33 (b), and 33 (c) are schematic sectional side views of a hinged-plate

air transfer valve for use in the appliance of Figures 31 (a), 31 (b) and 31 (c), in three modes of operation; Figures 34 (a), 34 (b), and 34 (c) correspond to Figures 33 (a), 33 (b), and 33 (c) but show a loose-plate air transfer valve in the same three modes of operation; Figures 35 (a), 35 (b), and 35 (c) correspond to Figures 33 (a), 33 (b), and 33 (c) and Figures 34 (a), 34 (b), and 34 (c) but show a diaphragm air transfer valve in the same three modes of operation;

Figure 36 is a sectional side view of two drawers of the appliance of Figures 31 (a), 31 (b) and 31 (c) fitted with bellows to minimise air transfer into the drawer compartments during drawer opening and closing; and Figure 37 is a partial sectional side view showing trace heating between a bin and its lid to prevent freezing at the bin/lid interface.

Whilst the disclosure of the Applicant's co-pending International Patent Application No.

PCT/GBOO/03521 is incorporated herein by reference, Figures I to 4 ofPCT/GBOO/03521 are reproduced in the drawings appended to this specification and will now be described to help put the present inventions into context.

Figures 1 to 4 show a refrigerator/freezer appliance 2 according to PCT/GBOO/03521. The appliance 2 is of upright cuboidal configuration, and comprises five rectangular-fronted drawers 4 arranged one above another and housed in a cabinet 6 comprising top 8, bottom 10, side 12 and rear 14 panels. Any of these panels can be omitted if it is desired to build the appliance 2 into a gap between other supporting structures; in particular, the side panels 12 can be omitted if neighbouring cupboards can be relied upon for support or otherwise to perform the function of the side panels 12. The panels 8,10, 12,14 may or may not be structural but if they are not, a frame (not shown) provides support for the various parts of the appliance. If a frame is provided, it is structurally unnecessary to have panels.

The drawers 4 can be slid horizontally into and out of the cabinet 6 by means of tracks or runners on the sides of the drawers 4 that will be described in more detail below. If there is no back panel 14, it is theoretically possible for a drawer 4 to be removed from the cabinet 6 in more than one direction, as shown in Figure 2.

Each drawer 4 comprises an insulated open-topped bucket-like container 16, at least one container 16 (in this case, that of the central drawer 4) being of a different depth to the other containers 16 to define a different internal volume. These containers 16 will be referred to in this specific description as storage bins or more simply as bins 16. The

bottom bin 16 leaves only a narrow gap to the bottom panel 10 of the cabinet 6, whereas the top bin 16 leaves a substantial space at the top of the appliance 2 under the top panel 8, allowing room for a compartment 18 that accommodates a refrigerator engine 20, for example including condenser and compressor means as is well known.

The relatively deep bin 16 of central drawer 4 is intended to hold bottles and other relatively tall items stored upright, whereas the other, relatively shallow bins 16 are for correspondingly shallower items. Compared to the shelves and other compartments defining the main storage volume of a conventional upright cold-storage appliance, all of the bins 16 have a favourable aspect ratio in terms of the substantial width of the access opening compared to the depth of the compartment thereby accessed. It is therefore very easy to reach every part of the interior of a bin 16 when a drawer 4 is opened, The interior of the cabinet 6 is divided by five insulated lids 22, one for each drawer 4, that are generally planar and horizontally disposed. When a drawer 4 is closed, the open top of its associated bin 16 is closed by an appropriate one of the lids 22 in a manner to be described. The lids 22 include cooling means 24 being evaporator elements of known type disposed in the lower face 26 of each lid 22 to cool the contents of a bin 16 closed by that lid 22.

Each bin 16 has a generally flat front face 28 that is exposed when the drawer 4 is closed.

The front face 28 could be provided with a decorative panel as is well known. When the drawer 4 is closed, the front face 28 of the bin 16 is bordered at the top by a control and display panel 30 dedicated to that bin 16, the panel 30 being co-planar with the front face 28. The panel 30 is supported by the front edge 32 of the appropriate lid 22, the panel 30 being recessed into the front edge 32 of the lid 22.

The control and display panel 30 contains a number of displays, switches and audible alarms, thus providing a user interface for each bin 16. For example, the interface will most commonly be used for selecting the temperature to which the bin 16 is to be cooled, but also contains temperature displays, on/off and fast-freeze switches, a light indicating when the drawer 4 is open and an audible alarm to indicate when the drawer 4 has been

open longer than a predetermined time or when the temperature inside the bin 16 has reached an upper or lower threshold. A rounded handle 34 extends across substantially the entire width of the top portion of the front face 28 to enable the drawer 4 to be pulled out when access to the interior of the bin 16 is required.

The bottom of the front face 28 of each bin 16 is bordered by a slot 36 that, as will be described, admits ambient air into the cabinet 6. To do so, each slot 36 communicates with an air gap 38 extending beneath the entire bottom face 40 of the associated bin 16 to meet a void 42 maintained behind each bin 16, the void 42 being defined by the inner surfaces of the back 14 and side 12 panels of the cabinet 6 and the backs 44 of the bins 16. As can be seen particularly from Figure 4, the void 42 extends behind each bin 16 from the base panel 10 of the cabinet 6 to communicate with the refrigerator engine compartment 18 at the top of the cabinet 6.

The air gaps 38 beneath the bins 16 and the void 42 behind the bins 16 also communicate with air gaps 38 to the sides 48 of the bins 16. Optionally, vents 46 are provided in the side panels 12 of the cabinet 6 adjacent to the bins 16 through which ambient air can also be admitted. As best illustrated in Figures 3 and 4, air gaps 38 extend around all bar the top side of each bin 16, so that ambient air entering the cabinet 6 through the slots 36 can circulate freely around the sides 48, bottom 40 and rear 44 of each bin 16. It will also be noted that ambient air can circulate freely over the top surface 50 of each lid 22. To allow this airflow over the uppermost lid 22, which does not have a bin 16 above, a slot 36 is provided under the front face 52 of the refrigerator engine compartment 18.

It will be noted that the piston action created by opening a drawer 4 that sucks ambient air into the interior of the appliance 2 does not pose a problem in this invention. In fact, this action is advantageous as it promotes circulation of ambient air within the cabinet 6.

Figure 4 shows that the refrigerator engine compartment 18 includes an impeller 54 exhausting through apertures 56 provided in the front face 52 of the refrigerator engine

compartment 18. As best seen in Figure 1, these apertures 56 extend horizontally across the width of the front face 52. The impeller 54 communicates with the void 42 behind the bins 16 to draw air from the void 42, thus continuously promoting the induction of ambient air through the slots 36 and the optional side vents 46. Upon entering the refrigerator engine compartment 18, this air is drawn through the heat-exchange matrix 58 of the condenser.

Accordingly, ambient air entering the cabinet 6 through the front slots 36 and, if provided, the side vents 46, leaves the cabinet 6 through the apertures 56 provided in the front face 52 of the refrigerator engine compartment 18, and so ambient air is circulated through the cabinet 6. More specifically, ambient air enters the appliance 2 where it immediately comes into contact with the outer surfaces 40,44, 48 of the bins 16 and warms them to ambient temperature (or substantially so, as a surface resistance effect means that a subambient boundary layer will remain due to the temperature gradient across the thickness of the bin wall) before being drawn towards the void 42 and then upwards through the void 42 by the circulation of the air. The arrows of Figure 4 demonstrate this circulation of air through the appliance 2. Accordingly, the interior of the cabinet 6 is kept close to ambient temperature, and only the interior of each bin 16 is cooled.

By exposing the external surfaces 28,40, 44,48 of the bin 16 to warmer air than it contains, there is no problem with condensation on the external surfaces 28,40, 44,48, and hence no problem with latent heat transfer to the bin 16 or the icing and crosscontamination difficulties of condensed water entering the cabinet 6.

In any event, cross-contamination would be unlikely to occur because each bin 16 is tightly sealed when its drawer 4 is closed. So, even if microbes enter the cabinet 6, they cannot readily gain access to other bins 16. It is also unlikely that two bins 16 would be open together at any given time. It would be possible to include means for enforcing this, for example using a mechanism akin to that used in filing cabinets for anti-tilt purposes, by preventing more than one drawer 4 being opened at a time. Such a mechanism will be described later.

When a bin 16 is open, its open top does not suffer much spillage of cold air, and when a bin 16 is closed, the horizontal seals 60 apt to be used in the invention are inherently better at sealing-in cold air than the vertical seals commonly used in upright refrigerators and freezers. Whilst horizontal seals are known in chest freezers, this invention does not suffer the inconvenience and space problems of chest freezers, instead being akin in those respects to the much more popular upright appliances. The seals 60 can have magnetic qualities, for example being operable by permanent magnets or electromagnets, or may employ hydraulics or pneumatics to expand or contract them.

As there has to be a large temperature gradient between the cooled inner surfaces 62 of each bin 16 and its outer surfaces 28,40, 44,48, the bins 16 are constructed from an efficient insulating material so that the gradient is easily maintained with the outer surfaces 28,40, 44,48 remaining close to the ambient temperature. Materials such as phenolic foam or polyurethane foam (optionally skinned with GRP or a polycarbonate in a composite structure) are particularly preferred for the construction of the bins 16.

If segregation of the contents of a particular bin 16 is required, that bin 16 may be fitted with removable inserts 64. The inserts 64 are of varying shape and dimensions and may be used to define many types of compartments. For instance, an insert 64 may be a thin partition with a length corresponding to the length or width of the bin 16 in which it is received. An insert 64 may be a box, with or without a lid, or an insert 64 may include clips for holding bottles in place or trays for holding eggs or the like. An insert 64 could also be a wire basket or shelf.

As can be seen in Figure 2, one or more of the bins 16 can be removed from the appliance 2 and fitted with an insulated transport cover 66. The bin 16 may then be taken away from the appliance 2, its insulated construction ensuring that it keeps its contents cool for a limited period of time. For instance, the bin 16 may be used as a cool-box, possibly in conjunction with ice-packs to keep the interior cool for as long as possible. Alternatively, the bin 16 with transport cover 66 may be kept close to the appliance 2 to provide added temporary cooled storage capacity, further bins 16 being fitted to the appliance 2 in that event. Further details of transport cover arrangements will be given later.

It is also possible for a transport cover 66 to include a refrigerator engine powered internally by batteries or a gas supply or externally by mains electricity or a vehicle electricity supply.

Although not shown in the general views of Figures I to 4, the Applicant's co-pending International Patent Application No. PCT/GBOO/03521 discloses ways in which a bin 16 can be moved with a major horizontal component of movement to gain access to the interior of the bin 16 and, during that access movement, also with a minor vertical component of movement to clear the lid 22. In subsequent development, the Inventor has devised other ways of clearing the lid 22 and gaining access to the bin 16. The Inventor has also devised other technical changes and improvements to PCT/GBOO/03521. That new matter will now be described with reference to the remaining Figures, in which the aforesaid reference numerals are used for like parts where possible.

In Figure 5, for example, the lid 22 is movable with respect to the structure to separate the lid 22 from the bin 16, thereby allowing the bin 16 to be moved subsequently in a single opening direction parallel to the general plane of the closed lid 22, i. e. having only a horizontal component of movement in the embodiment shown. In the very simple example shown in Figure 5, the lid 22 is attached to the structure behind the rear edge of the lid 22 by horizontal hinges 68 that enable the lid 22 to be pivoted upwardly at its front edge to an extent limited by the bin 16 above. This upward movement of the lid 22 lifts compressible magnetic seals 60 off the top edge 70 of the bin 16 and is sufficient to free the bin 16 to be slid horizontally on simple runners, with no need for the cranks, rollers, ramps and so on that are variously described in PCT/GBOO/03521 to effect vertical movement of the bin 16 upon opening and closing. The raised lid 22 is held up by a counterbalance weight 72 or a spring compensation device that biases the lid 22 into the raised position ready for the return of the bin 16 and optionally also into the lowered position atop the bin 16 when the bin 16 has been returned and the lid 22 has been lowered back onto the top edge 70 of the bin 16.

It will be appreciated that the position of the hinges 68 behind the rear edge of the bin 16

ensures that the rearmost seals 60 are lifted clear of the bin 16 or that their pressure upon the top edge 70 of the bin 16 is at least reduced to the extent necessary to free the bin 16 for horizontal movement.

It is emphasised that the simple arrangement of Figure 5 is shown merely to illustrate the concept of a moving lid 22 and that other ways of raising a lid 22 can clearly be devised. For example, an arrangement of solenoids, actuators, cams or cranks can be used to raise the entire lid 22 into a raised position that is generally parallel to its lowered position. It is also possible to retract the seals 60 upwardly into the lid 22 or downwardly into the bin 16 so as to free the bin 16 for movement.

Movement of the lid 22 can also be linked to the movement of the associated bin 16 or of a movable support for that bin 16, so that initial opening movement of the bin 16 or its support causes the lid 22 to move apart from the bin 16 and, vice-versa, at or toward the end of a closing movement of the bin 16 or its support.

In another way of clearing the lid 22 and gaining access to the bin 16, the Inventor has realised the potential benefit of separating horizontal and vertical movement of the bin 16.

Put more specifically, the Inventor sees benefit in ensuring that when the bin 16 and the lid 22 come into contact with each other, that contact does not involve a sliding or wiping motion which otherwise could cause the seals 60 to wear and deteriorate over long periods of frequent use. Such a sliding or wiping motion across the seals 60 should also be avoided when the bin 16 and the lid 22 are pulled apart. The movable-lid variant of Figure 5 has this benefit, as does the fixed-lid variant of Figures 6 (a) and 6 (b) which will now be described.

In Figure 6 (a), a drawer 4 in accordance with the invention is closed with its bin 16 sealed to the associated lid 22 by being raised against the lid 22 to compress a peripheral horizontal seal 60. Figure 6 (b) shows the same drawer 4 in two further positions. In solid lines, to the left in Figure 6 (b), the drawer 4 is partially open in that the bin 16 has dropped vertically away from the lid 22 to clear the seal 60, but the bin 16 has not moved horizontally. In dashed lines, to the right in Figure 6 (b), the drawer 4 is fully open: the bin

16 has been moved horizontally on telescopic runners 74 to afford access to its interior. The telescopic runners 74 are of two-or three-piece construction, as Figure 7 also shows. An outer rail 76 is attached to the adjacent side panel 78 of the cabinet and so remains stationary in use, whilst one or more inner rails 80 travel forward and back as the drawer 4 is opened and closed. As the rails 76,80 reside within the interior of the cabinet that remains at or near to the ambient temperature, there is no problem of ice formation that could jam the sliding movement of the rails 76,80.

Figures 6 (a) and 6 (b) show a bin transport mechanism associated with the telescopic runners. That mechanism is also shown in Figure 7 in a front part-sectional detail view.

Specifically, the bin transport mechanism on each side of the bin 16 comprises a transportation plate 82 fixed to the respective telescopic runner. As can be appreciated in Figure 7, the transportation plate 82 lies generally vertically beside the bin 16 and its vertical upper portion 84 is folded away from the bin 16 to define a recess between itself and the bin 16. That recess accommodates a pair of vertically-oriented movement transfer wheels 86 that are rotatably attached by horizontal spindles 88 to the upper portion 84.

Figures 6 (a) and 6 (b) show that the pair of movement transfer wheels 86 are disposed one forward, one rearward on each transportation plate 82 to each side of the bin 16.

Each movement transfer wheel 86 is received by and constrained to move in a respective wheel housing 90. Each wheel housing 90 comprises a wheel channel 92 being an inverted U-section that opens downwardly to receive an upper portion of each movement transfer wheel 86 and to constrain that wheel 86 against sideways movement. The base of the Usection bears against and supports a horizontal shoulder surface under an overhanging flange 94 that is integral with the wall of the bin 16. As can be seen in Figure 8, the wheel channels are under respective opposed ends of the flange 94 and are linked by a length of flat bar 96 that also lies under the flange 94. The central portion of the flange 94 between the wheel housings 90 overhangs that bar 96 to define a convenient lifting handle for use when the bin 16 is removed from the appliance 2.

Each movement transfer wheel 86 can move forwardly and rearwardly within its

associated wheel housing 90 to a limited extent with respect to the bin 16. Accordingly, each wheel housing 90 has formations associated with the wheel channel that constrain and control the movement of the respective movement transfer wheel with respect to the bin 16. Those formations are best shown in the detail view of Figure 9 of the drawings.

Firstly, forward and rearward movement of the movement transfer wheel with respect to the bin 16 is limited by forward and rearward buffers 98,100 respectively. Each buffer 98, 100 defines a respective rest position for the movement transfer wheel 96 so that when the movement transfer wheel 96 is against the forward buffer 98, the wheel 96 is at a forward rest position and when the wheel 96 is against the rearward buffer 100, the wheel 96 is at a rearward rest position.

Conveniently, the rearward buffer 100 of a rearward wheel housing 90 has a resilient backstop 102 on its rearward surface as shown in Figure 9, that bears against a suitable fixed barrier (not shown) to limit the rearward travel of the bin 16.

Secondly, restraining fingers 104,106 extend from the buffers 98,100 substantially parallel to the base of the wheel channel 92. The fingers 104,106, the buffers 98,100 and the wheel channel 92 define pockets that can receive the movement transfer wheel 86 at the respective rest positions and the resilient fingers 104,106 prevent that wheel moving away from the wheel channel when at either of those positions. Specifically, a forward restraining finger 104 extends rearwardly from the forward buffer 98 and a rearward restraining finger 106 extends forwardly from the rearward buffer 100. The forward restraining finger 104 has the additional feature of a free end portion 108 bent toward the wheel channel 92 to define an opening narrower than the diameter of the associated movement transfer wheel 86. The forward restraining finger 104 is resiliently flexible to allow the movement transfer wheel 86 to pass through the opening into the forward rest position, where the wheel 86 is then engaged and held by the resilience of the forward restraining finger 104. Moving the movement transfer wheel 86 back out of the forward rest position is only possible upon overcoming the resilience of the forward restraining finger 104.

Thirdly, a track connects the buffer plates 98, 100 to define a running surface for the movement transfer wheel 86. The track has flat end portions 110, 112 parallel to the base of the wheel channel 92, namely a forward end portion 110 attached to the base of the wheel channel 92 and a rearward end portion 112 spaced from the base of the wheel channel 92. Those end portions 110,112 coincide with the forward and rearward rest positions of the movement transfer wheel 86 and are connected by a ramp 114.

A resilient stud 116 at the junction between the rearward end portion 112 and the ramp 114 creates an obstacle that must be overcome if the movement transfer wheel 86 is to move out of its rearward rest position and then forwardly along the ramp 114. This stud 116 therefore helps to keep the movement transfer wheel 86 in its rearward rest position at which the drawer 4 is closed and the bin 16 is sealed to the lid 22. Also, the feel of the drawer movement as the movement transfer wheel 86 over-rides the stud 116 gives the user a positive indication of when the drawer 4 and the bin 16 have reached their closed and sealed states.

Elegantly, the buffers 98,100, the track 110,112, 114 and the restraining fingers 104,106 are folded or fabricated in a single component that it simply fixed within the base and side walls of the wheel channel 92, as shown in Figure 9. The wheel channel 92 spreads the loads applied to the track 110, 112,114, buffers 98,100 and restraining fingers 104,106 in use, and applies those loads to the bin 16 via the flange 94.

Figures 10 (a) and 10 (b) show how the height of the bin 16 with respect to the runners 74 responds to the position of the movement transfer wheel 86 within the wheel housing 90. It will be appreciated from Figure 10 (a) that when the movement transfer wheel 86 is in the rearward rest position against the rearward buffer 100, the wheel channel 92 and hence the bin 16 is raised, whereas when the movement transfer wheel 86 moves along the ramp 114 to the forward rest position against the forward buffer 98, the wheel channel 92 and hence the bin 16 is lowered.

Returning then to Figures 6 (a) and 6 (b) to see the bin transport mechanism in operation, Figure 6 (a) shows the bin 16 raised against and sealed to the associated lid 22. In this

instance, the bin 16 has been slid to its rearmost extent, as has the runner 74 with the attached transportation plate 82. The runner 74 has been slid rearwardly to that extent by pushing the attached front panel 118 of the drawer 4 rearwardly as far as it can go.

Consequently, the movement transfer wheels 86 supported by the transportation plate 82 are forced into the rearward rest position with respect to their respective wheel housings 90, at which position the wheel channels 92 and hence the bin 16 are raised.

The left-hand portion of Figure 6 (b) in solid lines shows how opening the drawer 4 by pulling a handle 120 on its front panel 118 initially pulls the runner 74 and the attached transportation plate 82 forwards. The bin 16 does not move forwards during that initial forward movement of the front panel 118 and runner 74 ; instead, the movement transfer wheels 86 supported by the transportation plate 82 move into the forward rest position: this allows the bin 16 to drop away vertically from the lid 22. It will also be apparent that when they reach their forward rest positions, each movement transfer wheel 86 bears against the respective forward buffer 98 and so can transmit continued horizontal draweropening force to the bin 16. In this way, when the bin 16 has cleared the seal 60, the drawer 4 can be opened fully into the position shown in dashed lines to the right in Figure 6 (b), in which the interior of the bin 16 is fully accessible. During that movement, the upwardly-bent free end portion 108 of the forward retaining finger 104 holds the movement transfer wheel 86 resiliently in the forward rest position so that the bin 16 does not move about unduly with respect to the runners 74. It will be noted that this opening movement of the bin 16 involves no sliding or wiping action across the seal 60.

When the drawer is fully open, the bin 16 can be removed from the appliance 2.

Preferably, the wheel housings 90 joined by the flat bar 96 remain behind when the bin 16 is removed in this way. However, it would also be possible to lift the bin 16 together with its wheel housings 90 so that the wheel housings 90 are lifted off the movement transfer wheels 86. In that event, it will be apparent from Figure 9 that a gap between the free ends of the retaining fingers 104,106 is just large enough for a movement transfer wheel 86 to pass through it when the bin 16 is lifted in this way. To reach that gap, it may be necessary to push the movement transfer wheel 86 rearwardly from the forward rest position past the upwardly-bent free end portion 108 of the forward retaining finger 104.

Figures 11 (a) and 11 (b) are akin to Figures 6 (a) and 6 (b) but show a variant in which closing a drawer 4 and opening it over the initial range of movement is lever-assisted. Such assistance may be particularly useful when closing a heavily-laden drawer 4, bearing in mind the need to lift the bin 16 slightly over the final portion of the drawer-closing movement. Elegantly, the front panel 118 of the drawer 4 serves as the lever by being pivotally attached to the runner 74 and/or the transportation plate 82 such that the pivot axis 122 lies horizontally just below the mid point of the front panel 118. Consequently, when the handle 120 at the top of the front panel 118 is pulled upon opening the drawer 4, the front panel 118 pivots about the pivot axis 122 (in a clockwise direction as drawn) and this causes the lower edge 124 of the front panel 118 to press against the lower front part of the bin 16. That pressure assists the relative movement between the runner 74 and the bin 16 that is necessary for the bin 16 to drop away from the lid 22.

More specifically, the lower edge 124 of the front panel 118 is associated with a bar 126 that engages a downwardly-opening hook 128 fixed to the front face of the bin 16. As the hook 128 opens downwardly, it allows the bin 16 to move up and down when making or breaking the seal ; it also allows the bin 16 to be removed from the appliance 2 by lifting it off the movement transfer wheels 86 as aforesaid. Yet, when the drawer 4 is being closed and closing pressure is therefore applied to the handle 120 at the top edge of the front panel 118 (which causes the front panel 118 to pivot in an anti-clockwise direction as drawn), the bar 126 applies force to the bin 16 via the hook 126 to hold the bin 16 while pushing the runner 74 rearwardly with respect to the bin 16. It is this relative movement that lifts the bin 16 against the lid 22 and benefits most from the mechanical advantage afforded by the lever.

A further feature evident from Figures 6 (a) and 6 (b) and Figures 11 (a) and 11 (b) is a rackand-pinion mechanism 130 whose primary purpose is to resist lateral sway of a drawer 4 supported by the runners 74 as it opens and closes. The rack-and-pinion mechanism 130 is also shown in plan view in Figure 12. In that mechanism, an arm 132 depends rearwardly and downwardly from the transportation plate 82 on each side of a bin 16 (the outline of which is shown in dashed lines in Figure 12) and terminates in a bearing 134 defining a

horizontal axis of rotation below and behind the rearward face of the bin 16. As can be appreciated from Figure 12, the bearings 134 of the respective arms 132 align and co operate to support a horizontal spindle 136 that spans the gap between the arms 132.

The spindle 136, in turn, supports a pair of pinions 138 fixed to the spindle 136 such that one pinion 138 is disposed adjacent each end of the spindle 136, just inboard of each bearing 134 that supports the spindle 136. The pair of pinions 138 are engaged with a correspondingly-spaced pair of parallel racks 140 that are on top of the lid 22 or other horizontal surface (notably the top surface of the base panel) below the drawer 4 in question, and extend orthogonally to the spindle 136 from the front to the back of that lid 22 or surface, at least as far as the opening movement of the drawer 4 dictates.

In use, when the drawer 4 is being opened or closed, the pinions 138 are constrained by the interconnecting spindle 136 to turn with one another. Any lateral sway experienced by the drawer 4 tends to move the spindle 136 out of its orthogonal relationship with the racks 140, and so tries to create a speed differential between the pinions 138 as they move along the racks 140. This conflict therefore causes one pinion 138 to apply torque to the other pinion 138 via the spindle 136; that torque tends to correct or at least resist the incipient sway. The spindle 136 may twist slightly as a result of the applied torque but this helps to prevent either of the pinions 138 skipping out of engagement with their racks 140 and hence potentially out of alignment with each other.

Figure 12 also shows a limit switch 142 near the rear of one of the racks 140, and a locking solenoid 144 also associated with the rack 140 but positioned slightly forward of the limit switch 142. The purpose of the locking solenoid 144 is to prevent the associated drawer 4 being opened, by for example blocking forward movement of the arm 132 that depends from the transportation plate 82. On the other hand, the limit switch 142 interacts with the arm 132 of the transportation plate 82, or with the spindle 136 supported by that arm 132, to sense opening and closing of the drawer 4.

By virtue of its rearmost position as shown in Figure 12, the limit switch 142 is triggered when the transportation plate 82 and its associated arm 132 is moved into or from its

rearmost position consistent with sealing the bin 16 against the lid 22. If the bin 16 is not sealed in that way, this will be indicated by the transportation plate 82 and its associated arm 132 being forward of its rearmost position and will be sensed by the limit switch 142. In that case, the limit switch 142 can be used to trigger an alarm (preferably after a timeout period has elapsed) and/or to cause the corresponding solenoids 144 of other drawers to lock their drawers 4 closed until the open or unsealed drawer 4 has been returned to its closed position and its bin 16 has been sealed against the associated lid 22. This allows only one drawer 4 to be open at a time and so provides an anti-tilt facility akin to a filing cabinet that, in the context of cold storage, also has the unique benefit of limiting crosscontamination between items stored in different drawers 4.

The locking solenoid 144 can also be controlled independently of a limit switch, for example by connecting all of the solenoids 144 of a multi-drawer appliance 2 to enable central locking of all of its drawers 4, preferably by a common key-operated switch (not shown). Preferably, to the benefit of energy consumption, the solenoid 144 unlocks its drawer 4 when energised and so locks that drawer 4 when de-energised. More preferably in such an arrangement, all of the drawers 4 remain locked with their solenoids 144 deenergised until a user-selected one of the drawers 4 is unlocked by, for example, pressing an appropriate button to energise its solenoid 144 or touching a corresponding touchswitch associated with the handle of that drawer 4. Once energised, a solenoid 144 may remain energised constantly until another drawer 4 is selected to be opened; preferably, however, that solenoid 144 is de-energised after a timeout period to lock its drawer 4 until a user selects that drawer 4 to be unlocked once more.

Whilst electric locking solenoids 144 have been mentioned, it will be clear to the skilled reader that other actuators or locking mechanisms operating on hydraulic, pneumatic or mechanical principles can be used instead.

Figures 13 (a), 13 (b) and 13 (c) show a bin 16 removed from a cold-storage appliance and fitted with a transport cover 66. The transport cover 66 is generally oblong in plan and has deep vertical sides that, as best shown in the sectional view of Figure 13 (c), define a skirt 146 having a continuous horizontal sealing surface 148 around a central recess 150 that

corresponds in shape and diameter to the cavity of the bin 16. That sealing surface 148 seals against a corresponding upper surface of the bin 16, defined by a peripheral horizontal flange 152 that extends outwardly around the cavity of the bin 16. Although not shown, supplementary seals of any known type can be used between the sealing surfaces so as to maintain a vapour seal.

The sectional view of Figure 13 (c), taken on line Y-Y of Figure 13 (a), also shows internal cooling means within the transport cover, in this case eutectic packs 154 in the recess 150 beneath the cover 66. The cooling means could alternatively be an internally-or externally-powered refrigerator engine or a heat exchanger supplied with coolant from another source. Beneath the cooling means is a drain tray 156 that collects drips of condensed moisture to prevent possible damage to or contamination of the contents of the bin 16. The drain tray 156 has inclined surfaces to channel that water to a central drain sump 158.

The plan view of Figure 13 (a) shows that the vertical side walls of the transport cover 66 have vertical ribs or castellations 160 extending from the top face 162 of the transport cover 66 though the full depth of the side wall to the sealing surface 148 of the transport cover 66. Those formations extend all around the side walls of the transport cover 66; their purpose will be explained below with reference to Figures 14 (a) and 14 (b). The side view of Figure 13 (b) shows that side walls of the transport cover 66 can also be provided with hand carrying points 164 being recesses to receive a user's fingers when that user lifts the covered bin 16. Additionally, Figures 13 (a) and 13 (b) both show C-shaped clips 166 that can snap-fit resiliently over the flange of the bin 16 and the sides of the transport cover 66 when those parts are placed together in overlying relation as shown.

Figure 13 (a) also shows a temperature indicator 168 and/or alarm, conveniently situated centrally on the transport cover 66 for good visibility. The temperature indicator 168 can simply be a temperature-responsive chemical indicator to alert a user as to the temperature within the bin 16 by changing colour or displaying other appropriate indicia. Optionally, the indicator 168 shows nothing until the temperature within the bin 16 climbs too high for safe storage and an alarm condition therefore exists. Of course, more complex electronic

indicators and visual/audible alarms can be used instead if their cost is no object. Referring now to the side elevation and plan views of Figures 14 (a) and 14 (b) respectively, these show a group of bins 16 when removed from a cold-storage appliance 2, each bin 16 being fitted with a transport cover 66 as shown in Figures 13 (a), 13 (b) and 13 (c). The group comprises six stacks each three bins high, the stacks being placed against each other to form a 3 x 2 rectilinear array in plan. Each bin 16 within the group may therefore have six neighbouring bins 16: one above, one below and one to each of its four sides. A floor 170 lies beneath the bottom-most bin 16 of each stack.

A problem of an equivalent group of conventional cold-storage bins is that their mutuallyabutting surfaces create an insulation trap that promotes condensation and icing. The interface between the floor 170 and the bottom-most bins 16 is susceptible to the same problems. This is the significance of the castellations or ribs 160 in the transport covers 66 of Figures 13 (a), 13 (b) and 13 (c): they define airflow slots 172 when placed side by side with counterpart transport covers 66 in mutually abutting relation. Those slots 172 communicate with vertical airflow channels 174 between the opposed side walls of neighbouring bins 16. Those vertical channels 174 are defined by the overhanging flanges 152 of the bins 16 and the overlying covers 66 which prevent the side walls 176 of the bins 16 touching one another. Figure 14 (a) also shows horizontal airflow channels 178 between successive bins 16 in each stack and between the bottom-most bins 16 and the floor 170. Those horizontal airflow channels can be defined by ridges (not shown) traversing the base of a bin 16 and/or the top of a transport cover 66, and communicate with the vertical channels 174 to ensure airflow around and between the bins 16 to minimise insulation traps and hence the prospect of condensation and icing.

Moving on to Figure 15, this side elevation broadly corresponds to Figure 14 (a) but shows stacked covered containers 180 which may be substantially larger than a portable bin 16, for example for bulk storage and transport of perishable items. Each container 180 has a respective refrigerator engine 182 capable of standalone operation, and there are enlarged air gaps 184 between the containers 182. The enlarged air gaps 184 allow for the convective escape of heat and exhaust gases from condensers and/or from power

generation/combustion taking place in each refrigerator engine 182 ; they also provide for the supply of cool fresh air necessary if the condensers are air-cooled or if the refrigerator engines 182 are fuel-burning.

Figure 16 broadly corresponds to Figure 15 but shows covered containers 180 that are relatively densely-stacked to maximise space efficiency in a confined space such as a ship's hold. To that end, each respective refrigerator engine 182 is connected to services being a mains power supply 186 and an auxiliary water-cooled condenser 188, as may for example be available from a ship's utility services.

Referring now to Figure 17, this shows a variant of the bin 16 in which, looking down into the open bin 16, arrays of parallel ribs or ridges 190 are formed in the side and bottom faces of the interior of the bin 16. These ribs or ridges 190 define a corresponding array of channels 192 that promote air circulation around objects cold-stored within the bin 16.

This circulation of air reduces the effect of insulation traps between those objects and the interior surfaces of the bin 16 with which those objects come into contact. In any event, the area of such contact is limited to the apices of the ribs or ridges 190 ; this, in itself, helps to reduce the insulation trap problem.

Returning to the appliance 2 itself, Figures 18 (a) and 18 (b) show preferred details of the lids 22 to which the bins 16 seal when fitted in the appliance 2. Figure 18 (a) shows that the lid 22 is oblong in plan view. The oblong dashed outlines of features below the lid 22 are also apparent. Starting inwardly and moving outwardly, those features are an evaporator 194 disposed centrally on the underside of the lid 22, a drain pan 196 disposed beneath the evaporator 194 to catch water that drips from the evaporator 194, and a recess 198 in the underside of the lid 22 that accommodates both the drain pan 196 and the evaporator 194.

As best appreciated from Figure 18 (b), which is a cross-section on line A-A of Figure 18 (b), the recess 198 is bounded by a peripheral skirt 200 depending from the lid 22. A pair of oblong compressible seals 60 lie one within the other on the lower end face 202 of the skirt 200. Those seals 60 are continuous save for an opening that accommodates an oblong-section drainage duct 204 leading rearwardly from the drain pan 196. The drain

pan 196 has an inclined base 206 to lead water toward that drainage duct 204, from which the water is channelled away from the lid 22 as Figure 19 will explain. A temperature sensor (not shown) can penetrates the skirt 200 above the seals 60 to measure the temperature within the cavity sealed by the bin 16 and the lid 22.

Figure 19 shows how it is preferred that separate drain ducts 208 run from each drain pan 196 of a multi-bin appliance 2. This minimises the risk of cross-contamination. Each duct 208 includes a U-bend 210 defining a sealing water trap and drains separately to a common tray 212. That tray 212 may be located above a compressor 214 of the appliance 2 as shown so that, over time, heat emanating from the compressor 214 evaporates the water from the tray 212 at least as quickly as that water accumulates in the tray 212. In addition or in the alternative, the condenser fan of the appliance 2 (not shown) can blow across the surface of water in the tray 212 so as to promote its evaporation.

Figures 20 (a) and 20 (b) show a further lid design suitable for use in a fan coil cooling system in which air is supplied to the bin 16 and extracted from the bin 16 via a remote fan coil unit. Such a system is also known as a forced air system, and the lid 22 in Figures 20 (a) and 20 (b) is hollow and partitioned to govern the flow of air on which such systems depend. Thus, cold air cooled by a heat exchanger (not shown) is piped under pressure from a fan (not shown) into a supply air plenum 216 disposed peripherally within the lid 22, from which that air enters the bin through supply air diffusion slots 218 around a base panel 220 defining the underside of the lid 22. Warmer air is extracted from the bin 16 through a centrally-disposed return air plenum 222 that communicates with the bin 16 through a central hole 224 in the base panel 220 and with the fan through a pipe 226 extending through the surrounding supply air plenum 216. The warmer air is drawn into the return air plenum 222 under low pressure created by the fan, and is then sent to the heat exchanger to be cooled and recirculated via the supply air plenum 216.

Moving on to Figures 21,22 (a) and 22 (b), these show how a fan coil cooling arrangement can be applied to a plurality of bins 16 having lids 22 like that of Figures 20 (a) and 20 (b). It will be appreciated that, for reasons of cross-contamination and independent temperature control in each bin 16, each bin 16 has a separate circulation path 228 although these

advantageously share a common heat exchanger 230 as shown.

Dealing with Figure 21 first, a plurality of storage bin lids 22 each have a respective dedicated air circulation path 228. Relatively warm air drawn from a storage bin 16 first passes a temperature sensor 232 used to assess the degree of cooling necessary, and then reaches a fan 234. The fan 234 propels the relatively warm air into a cooling compartment 236 in which it is cooled by a cooling means 230 in the form of a heat exchanger matrix.

From there, the cooled air returns to the bin 16 via the bin lid 22. The speed of each fan 234 can be varied in response to the degree of cooling deemed to be necessary, or the fan 234 can be cycled on and off with variable frequency and/or cycle length to attain a suitable air flow rate through the heat exchanger matrix 230 over a period of time.

It will be noted how the same heat exchanger 230 extends across all of the air circulation paths 228 but that there is a substantially airtight seal effected by partitions 238 between neighbouring cooling compartments. Heat exchanger pipes 240 must pass through holes in the partitions 238 but seals such as grommets are provided around the pipes 240 within the holes. Whilst this common or series heat exchanger 230 applies broadly the same cooling capacity to each air circulation path 228, the independently adjustable fans 234 control the rate of heat transfer from the air and so provide for an independent cooling effect, and hence independent temperature control, in each air circulation path 228.

As a major advantage of the fan coil cooling arrangement is that moisture is rejected outside the storage area, the heat exchanger 230 has defrost facilities including drip trays 242 and drainage ducts 244. A drip tray 242 and drainage duct 244 could be common to the entire heat exchanger 230 but preferably there are dedicated drip trays 242 and drainage ducts 244 or each air circulation path 228. This minimises the need for openings in the partitions 238 and so reduces the risk of cross-contamination. For that purpose, each drainage duct 244 also includes a U-bend 246 defining a sealing water trap. The defrost facilities may be supplemented by heaters (not shown) relying, for example, upon electrical heating elements or hot gas supplied from a compressor or a condenser of the appliance.

Figures 22 (a) and 22 (b) show an elegant practical arrangement of the multiple fan coil cooling system shown schematically in Figure 21, Figure 22 (a) being a plan view of a fan coil unit package 248 and Figure 22 (b) being a cross section on line A-A of Figure 22 (a). Incoming relatively warm air drawn from the bin lids 22 through flexible inlet pipes 250

enters respective U-shaped tracts 252 that pressurise and cool the air and invert the air flow through 1800 before it is returned to the associated bin lid 22. As can be appreciated from Figures 22 (a) and 22 (b), the U-shape lies on its side and in a vertical plane to define upper and lower chambers 254,256. The upper chamber 254 of each tract contains a fan 234 and a finned evaporator 230 downstream of the fan 234, and the lower chamber 256 returns the air thus cooled under the upper chamber 254 for supply back to the associated bin lid 22 through a respective flexible outlet pipe 256. As in Figure 21, the evaporators 230 are in series but in this case they are connected by cooling fluid lines 258 extending through sealed holes from one upper chamber 254 to the next.

Figure 22 (a) shows how the tracts 252 are separated from each other to leave an insulating air space 260 between neighbouring tracts. This is beneficial because the invention makes it possible for neighbouring tracts 252 to operate at substantially different temperatures.

The insulating spaces 260 may be filled with insulating material if desired and in the embodiment illustrated, those spaces 260 further serve to accommodate a drain duct 244 from a drip tray 242 disposed beneath the evaporator 230 for defrosting purposes. One such drain duct 244 and drip tray 242 are visible beneath the evaporator 230 in Figure 22 (b).

Figures 23 and 24, viewed together, give component details of an exemplary embodiment that has four drawers 4 each associated with a respective evaporator 230, and a hot-gas defrost facility. As in PCT/GBOO/03521, the bin 16 of each drawer 4 comprises a separate independent cooled storage area. Accordingly, the temperature can be set independently so that, if desired, a different temperature can be set for each bin 16. In fact, temperatures can be set below zero Celsius, so that a bin 16 can be used as a freezer or as a refrigerator at the user's option. In this way, the appliance 2 may function as a combined refrigerator and freezer where, advantageously, the ratio of refrigerated storage space to frozen storage space can be varied easily by changing the use of one or more of the bins 16. Of course, it

will be appreciated that the drawers 4 can all be used as refrigerators or can all be used as freezers so that, in effect, the appliance becomes either a dedicated refrigerator or freezer.

Consequently, each evaporator 230 and other components associated with each drawer 4 are capable of serving the maximum duty of the compartment defined within each bin 16, from ambient down to, say, minus 20 Celsius as may be selected by a user at will. On the other hand, system components such as the compressors 262AJB, condensers etc. are capable of serving the maximum duty of the entire appliance, again from ambient down to minus 20 Celsius. The system control takes account of the potentially large fluctuations in system duty between all drawers 4 being set to freeze and all drawers 4 being set merely to refrigerate. In this way, the invention goes against conventional wisdom in that it does not demand separate compartments for refrigeration and freezing.

It would be possible to use only one compressor 262 but it will be noted that the embodiment shown in Figures 23 and 24 has two compressors, being a relatively large major compressor 262A and a relatively small minor compressor 262B. The major compressor 262A can be used on its own or preferably in conjunction with the minor compressor 262B to achieve rapid pull-down of bin temperature (s) when necessary.

However, once all of the bin temperatures are within their desired temperature ranges, the major compressor 262A shuts down in favour of the minor compressor 262B, to the benefit of energy consumption. Thereafter, the minor compressor 262B is capable of keeping the appliance economically'ticking over', in other words maintaining all of the bin temperatures within the desired temperature ranges until an event occurs that warrants rapid cooling. Such an event might be a user setting a bin 16 to a substantially lower temperature so as to convert it from refrigeration to freezing, or filling a bin 16 with relatively warm items that need to be brought quickly to their appropriate storage temperature.

Figures 23 and 24 also show shut-down means that further minimise loss of cold air and cooling of ambient air by switching off an evaporator 230 when the associated drawer 4 is open. For each drawer 4, the aforementioned limit switch 142 (shown in Figure 12) acts through cold store logic 264 to switch off the evaporator 230 by closing the associated

temperature control valve 266 until the drawer 4 is closed and the bin 16 is sealed once more. This facility is particularly useful when a bin 16 is removed from the appliance 2 for a period of time, so that the user does not have to remember to turn off the associated evaporator 230.

Apart from the vertical array of drawers 4 common to the embodiments described above, a side-by-side arrangement of drawers 4 is also contemplated as shown in Figures 25 (a), 25 (b) and 25 (c). The front view of Figure 25 (a) shows a four-drawer bench-type appliance 268 (to which Figures 23 and 24 also refer) in which the drawers 4 are in two adjacent columns of two drawers 4 each. Thus, the appliance 268 is low enough to have a worktop 270 over the drawers 4, straddling the two columns. This embodiment of the invention is therefore suitable for use as a refrigerated food preparation and/or servery unit.

The depth of the drawers 4 is maximised within the limited available height by mounting the refrigerator engine 272 and control panel 274 in a side-slung position to one side of the appliance 268 as shown. Also, the side view of Figure 25 (b) and the enlarged detail crosssectional view of Figure 25 (c), taken on line X-X of Figure 25 (a), shows that the front edge of the worktop 270 has a raised lip 276 that helps to prevent spillages on the worktop 270 dripping down onto or into the drawers 4 below.

Figures 25 (a) and 25 (b) show how an appliance 268 of the invention can be mounted on castors 278 and Figures 26 (a) and 26 (b) show how those castors 278 can be heightadjustable to level the appliance 268 on a non-level floor 280. Specifically, each castor 278 has a base plate 282 constrained to move within a housing 284 fixed under the structure of the appliance 268. One side 286 of the housing embraces an edge of the base plate 282 and acts as a fulcrum for tilting movement of the base plate 282. This tilting movement raises or lowers the appliance 268 with respect to the floor 280, as a comparison of Figures 26 (a) and 26 (b) will make clear.

The base plate 282 is caused to tilt, and is held in that position, by a jacking wedge 288 defining a downwardly-facing ramp surface 290 that overlies and acts upon the edge 292

of the base plate 282 opposed to the fulcrum. The jacking wedge 290, in turn, is constrained to slide horizontally between the underside of the appliance 268 and a parallel retaining plate 294 being part of the housing 284. The jacking wedge 290 is advanced and retracted by a horizontal jacking screw 296 received in a tapped hole that penetrates an end plate 298 of the housing 284 opposed to the fulcrum. As the comparison of Figures 26 (a) and 26 (b) shows, the appliance 268 is in its lowest position when the jacking wedge 288 is fully retracted against the end plate 298 of the housing 284. This position is shown in Figure 26 (a). Figure 26 (b) shows the jacking wedge 290 advanced to near the limit of movement of the screw 296, the appliance 268 therefore approaching its highest position.

Figures 27 (a), 27 (b) and 27 (c) correspond to Figures 20 (a), 20 (b) and 20 (c) of PCT/GBOO/03521 and are schematic views of the invention applied to bulk storage in a cold store and commercial transportation in a refrigerated vehicle. Figure 27 (a) shows a vehicle 300 carrying a standardised refrigerated storage container 302 that is functionally akin to, albeit far larger than, the bins 16 of most of the preceding embodiments: it is an insulated container defined by normally-closed walls having an open top closed by an openable insulated cover 304 that preferably includes a cooling means in the form of a roof-mounted refrigerator engine 306. As shown in Figure 27 (b), the cover 304 can be opened so that goods 308 can be loaded and unloaded from above using an overhead gantry crane 310 without losing cold air from the container 302. A further advantage is that the entire plan area of the container 302 can be accessed readily by the crane 310 rather than relying for access upon a restricted door in the rear or side of the container 302.

Figure 27 (c) shows how full containers 302 can be left without covers in the refrigerated environment of a cold store 312, which may be a building as shown or some other refrigerated storage facility such as a ship's cargo hold. The associated covers 304 and refrigerator engines 306 can be used elsewhere during that storage period. If containers 302 are stacked, a container 302 can serve as the cover for the container 302 below. When required, a container 302 can be fitted with a cover 304 and refrigerator engine 306 and lifted on to a suitable vehicle 300 for transport wherever necessary.

As the sectional side view of Figure 28 shows, bulk materials 308 can be stacked within

the container 302 on pallets 314, each having lifting tackles 316 for top lifting as shown in Figure 27 (b). Whilst the containers 302 shown in Figures 27 (a), 27 (b), 27 (c) and 28 can be stacked when their covers 304 are removed, their external roof-mounted refrigerator engines 306 prevent stacking when the covers 304 are in place. In contrast, the alternative container arrangement of Figure 29 can be stacked when the cover 304 is in place because the refrigerator engine 306 is side-slung at one end of the container 302. As shown in dashed lines in Figure 29, the refrigerator engine 306 can be removed with the cover 304 as a unit, although this is optional.

Figures 30 (a), 30 (b) and 30 (c) show the truck 300 of Figure 27 (a) being loaded or unloaded at a specially-adapted cold-storage facility 316. Firstly, in Figure 30 (a), the truck 300 is reversed to just outside a loading bay 318, where the cover 304 of the container 302 is removed. Then, in Figure 30 (b), the truck 300 is reversed into the loading bay 318 to align the open top of the container 302 with a hatch 320 in the underside of an overhanging containment structure 322. The hatch 320 is normally closed by a cover 324 that retains cold air within the containment structure 322 but when a container 302 is in place below, the hatch cover 324 is drawn back to open the hatch 320 as shown in Figure 30 (c). This allows loads 308 to pass from the containment structure 322 to the container 302 and vice versa, using an overhead crane 310 that travels along a gantry 326 within the containment structure 322, above the hatch 320.

Optionally, as shown in Figures 30 (b) and 30 (c), the periphery of the open-topped container 302 is sealed to the containment structure 322 around the hatch 320 to minimise loss of cold air. Using suitable means such as pneumatics or hydraulics, the seal 328 can be extended like a bellows to bridge the gap between the container 302 and the containment structure 322. Such a seal 328 can expand upwardly from the container 302 or downwardly from the containment structure 322. Alternatively, a seal between the container 302 and the containment structure 322 can be made and subsequently released by raising and subsequently lowering the truck 300 on suitably-adapted suspension or auxiliary rams, or on a vertically-movable platform 330 that supports the truck 300.

Referring now to Figure 31 (a), this is a front elevation of a cold-storage appliance 332 that is functionally akin to the aforementioned Ewen prior art-in that much of the bin exterior may be exposed to air below ambient temperature-but addresses many of its problems. In outward appearance, the appliance of Figure 31 (a) is similar to the bench-type appliance shown in Figures 25 (a) and 25 (b) and has its drawers 4, control panel 274 and refrigerator

engine 272 in similar positions under a worktop 270. Similarly, Figure 31 (b)-a section on line A-A of Figure 31 (a)-shows that each drawer 4 comprises a lid 22 within the cabinet and a bin 16 movable forwardly from the cabinet on telescopic runners 74. Figure 31 (c) -a section on line B-B of Figure 31 (a) -shows those runners 74 beside the bin 16.

However, like Ewen and unlike the preceding embodiments, there is no provision for vertical movement of the bin 16 with respect to the lid 22: instead, the bin 16 simply slides horizontally past the close-fitting lid 22. The gap between the bin 16 and the lid 22 that is therefore necessary requires the creation of a complete external vapour barrier around the compartment that houses each drawer, so as to overcome the associated moisture transmission and cross-contamination problems. Thus, as Figure 31 (b) shows, the front panel 118 of each drawer extends beyond the corresponding drawer aperture defined between the lids 22 or between a lid 22 and a bottom panel 334. The overlapping portion of each front panel 118 has vertical magnetic seals 336 on its rear face that, when the drawer 4 is closed, seal by flexible resilience and magnetic attraction against the opposed front faces of the lids 22 and/or the bottom panel 334 as appropriate. The drawer compartments are also sealed from each other; this applies especially to penetrations and service connections that run between neighbouring drawer compartments. It also applies to water drainage from the drawer compartments: separate drain lines (not shown) should be run individually from each compartment and should each have in-line water traps, akin to the drainage arrangement shown in Figure 19 above.

Figure 31 (c) also shows L-section bin supports 338 depending from the runners 74 to cradle the bin 16 in a removable manner. Each drawer compartment should be of the minimum volume that allows access to the bin 16 and the associated runners 74.

Ideally, the walls of each drawer compartment should be of a thin, poorly-insulating material with all of the external surfaces exposed to ambient air. That ideal is not practically achievable, although use of a thin material that conducts heat from outside the drawer compartment and promotes convection of heat within the drawer compartment is to be encouraged. In reality, a temperature gradient will form over time inside the sealed compartments due to the insulating effect of the external enclosure and the air cavity around the bin 16, coupled with the refrigerating effect of the gap between the bin 16 and the lid 22. Additionally, an insulation trap will occur where external surfaces of a compartment are adjacent to other compartments. This further cools the air around the bin 16 and so increases the temperature gradient.

For this reason, Figures 32 (a), 32 (b), and 32 (c) propose three different ways of minimising the effects of temperature gradients and cooling within each drawer compartment of the appliance of Figures 31 (a), 31 (b) and 31 (c). Figure 32 (a) shows a circulating fan 340 in a duct 342 behind the drawer compartment 344 that draws air from and pumps air back into the compartment 344. The circulation thus created in the air within the compartment 344 keeps the external surfaces of the bin 16 at an even temperature. Figure 32 (b) shows an electric or hot gas heater 346 below the bin 16 to create convection currents in the air within the compartment 344 and to warm most of the external surfaces of the bin 16 to near-ambient, ambient or even higher than ambient temperature. Figure 32 (c) shows air gaps 348 akin to those described above with reference to Figures 1 to 4, save that the air gaps 348 are around and between the drawer compartments 334 rather than around the bin 16 itself. Although not visible in Figure 32 (c), the air gaps 348 can extend over the sides of the drawer compartment 334 as well as the underside and back of that compartment 334 as shown. Again, air within the air gaps 348 can be warmed if needs be.

The next group of drawings-Figures 33 to 35-show various air transfer valves that mitigate the piston effect experienced when opening and closing a drawer 4 of the appliance 332 of Figures 31 (a), 31 (b) and 31 (c). Figures 33 (a), 34 (a) and 35 (a) show the status of the respective valves when the bin 16 is static, for example when the bin 16 is closed. Figures 33 (b), 34 (b) and 35 (b) show the status of the respective valves when the bin 16 is being opened, and Figures 33 (c), 34 (c) and 35 (c) show the status of the

respective valves when the bin 16 is being closed.

Dealing firstly with the features in common to all of the valves of Figures 33 to 35, they comprise an inlet duct 350 closable by an inlet valve member 352, an exhaust duct 354 closable by an exhaust valve member 356, and an intermediate duct 358 connected to the drawer compartment 344 that communicates with a central valve chamber 360 disposed between the valve members 352,356. The inlet valve member 352 normally rests on an inlet valve seat 362 around a port 364 between the inlet duct 350 and the central valve chamber 360, and opens into the central chamber 360. Similarly, the exhaust valve member 356 normally rests on an exhaust valve seat 366 around a port 368 between the exhaust duct 354 and the central valve chamber 360, but the exhaust valve member 356 opens into the exhaust duct 354.

Both of the valve members 352,356 are in their respective rest positions when the bin 16 is static, as Figures 33 (a), 34 (a) and 35 (a) show. When the drawer 4 is being opened, however, air is drawn from the central valve chamber 360 toward the drawer compartment 344 as shown in Figures 33 (b), 34 (b) and 35 (b). The resulting low pressure in the central valve chamber 360 causes the inlet valve member 352 to open and admit air from the inlet duct 350 through the inlet port 364 into the central valve chamber 360 and from there into the drawer compartment 344. Conversely, when the drawer 4 is being closed, air is forced from the drawer compartment into the central valve chamber 360 as shown in Figures 33 (c), 34 (c) and 35 (c), which increases the pressure in the central valve chamber 360 and so causes the exhaust valve member 356 to open. The air in the central valve chamber 360 thereby exhausts through the exhaust port 368 and out of the exhaust duct 354.

The inlet duct 350 draws ambient air from outside the cabinet of the appliance 332 and the exhaust duct 354 similarly exhausts air to outside the cabinet. Thus, such air as is displaced by the piston action of the opening and closing drawer 4 does not travel between compartments 344 of the appliance 332 and so does not have a chance to crosscontaminate between those compartments 344. It will be noted that in the passive or rest position shown in Figures 33 (a), 34 (a) and 35 (a), the valves maintain the vapour barrier of the cabinet. The valves and the inlet and exhaust ducts 350,354 should be sized and

located to minimise disturbance to the cold treated air in the bin 16 as the bin 16 experiences piston action upon opening and closing the associated drawer 4. The differences between the valves of Figures 33 to 35 lie mainly in the valve members and in their sealing arrangements with respect to their seats. The valve members 352,356 in Figures 33 and 34 are rigid flaps or plates having magnetic or compressible seals 370 around their periphery that co-operate with the valve seats 362,366 to seal the respective ports 364,368. Both variants rely upon gravity and pressure differences to close the respective ports 364,368. In Figure 33, the plates 352,356 are hinged to one side so as to lift to the other side when they open their ports 364,368. In Figure 34, however, the plates 352,356 lie loosely on their seats 362,366 and may be inclined as shown to encourage one side to lift in favour of the other side when they open their ports 364,368. In contrast, the valve members 352,356 of Figure 35 are curved diaphragms whose curvature and resilience biases them shut, but which flex resiliently in response to pressure changes to open by flattening against the bias. It will also be evident from Figure 35 that the diaphragms 352,356 have a flexible peripheral flange 372 that seals against the valve seats 362,366. The diaphragm valve of Figure 35 has the benefit that its operation does not rely upon gravity to any extent; hence, the valve can be oriented in any way that may be desired.

Another way to minimise cross-contamination between drawer compartments 344 is to maintain a vapour barrier effective throughout the range of movement of a drawer 4. Figure 36 shows a way of achieving this and depicts two drawers 4 of an appliance, one above the other. The upper drawer 4 is closed and the lower drawer 4 is open and it will be noted that each is fitted with a bellows 374 attached to the rear face of the bin 16 in each drawer 4. The cross-section of each bellows 374 substantially matches the oblong crosssectional shape and size of the drawer compartment 344, and each is capable of extending the full length of the drawer compartment 344 swept by the bin 16. Thus, using a piston and cylinder analogy, the bellows 374 sweeps substantially all of the volume of the associated drawer compartment 344.

The bellows 374 attached to the bin 16 of the upper drawer 4 is collapsed compactly

behind the bin 16 in the closed upper drawer 4 but the corresponding bellows 374 of the open lower drawer 4 is fully extended. It will be appreciated that each bellows 374 is closed at its bin end and open to its rear end, and that the rear end is sealed around its periphery to the surrounding walls of the drawer compartment 344 to form a vapour barrier. The open end of each bellows 374 communicates directly with the surrounding atmosphere so that fresh air is drawn into the bellows 374 as the drawer 4 opens and exhausts as the drawer 4 closes. However, there in no mixing between the incoming air in the bellows 374 and the air that is or was in the drawer compartment 344.

Referring finally to Figure 37 of the drawings, this shows that trace heating may be applied locally to the skirt depending from the lid 22 so as to prevent icing at the bin/lid interface 376. The heating may be effected by electric elements 378 or hot gas means, and may be continuous or applied only when it is desired to open the bin 16.

Among many variations of the inventions herein, the trace heating facility of Figure 37 could be applied to any of the foregoing arrangements in which relative movement (preferably vertical movement) between the lid 22 and the bin 16 breaks the seal and clears the bin 16 from the lid 22 (or vice versa) so that the bin 16 can be opened fully for access.

It is also possible for heat to be recovered from various heat-emitting parts of refrigerator engines, such as heat exchangers, motors and so on, and applied to warming the bin/lid interface or the external surfaces of the bin 16 within a drawer compartment. This saves energy by using waste heat that would otherwise be rejected to atmosphere.

The invention has wide ranging applications and benefits for storing, handling, distributing, transporting and delivering items in the right condition, notably: precise variable temperature and humidity control that could even include heating rather than merely cooling; mechanical protection of stored items;

sterile storage with minimal risk of cross-contamination ; the option of storage in partial vacuum conditions ; the option of storage in a preservative holding gas environment ; isolation of stored items against vibration and agitation; and containment of, or protection against, radiation and bio hazards.

In general, therefore, reference should be made to the appended claims and other general statements herein rather than to the foregoing specific description as indicating the scope of the inventions. In interpreting the inventions, it should be understood that although features of the illustrated embodiments have been described in combination with each other and although such combinations may have advantages of their own, many of those features can be applied independently. So, those features are considered to be independently patentable whether within or beyond the inventive concepts expressed herein.

Claims (65)

1. CLAIMS 1. A cold-storage appliance including : an open-topped insulating container defining an external surface ; an insulating lid adapted to close the open top of the container; a cooling means adapted to cool the interior of the container; and a structure supporting the container, the lid and the cooling means; wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afford access to its interior or to close the container, and wherein the lid is mounted to the structure for movement relative to the structure and the container to free the container from the lid upon opening or to bring the container and the lid together upon closing.
2. 2. The appliance of Claim 1, wherein the lid can be tilted relative to the structure and the container.
3. 3. The appliance of Claim 2, wherein the lid is hinged to the structure, the hinge defining a pivot axis horizontally spaced from the container.
4. 4. The appliance of any preceding Claim, wherein the lid is movable transverse to the direction of movement of the container.
5. 5. The appliance of any preceding Claim, including lid transport means responsive to movement of the container or of a support means movable to support the container during said movement.
6. 6. The appliance of Claim 5, wherein the lid transport means moves the lid before the container starts moving upon opening and after the container has stopped moving upon closing.
7. 7. The appliance of Claim 5 or Claim 6 and comprising support means movable to support the container during said movement and lid transport means between the support means and the lid that responds to movement of the support means to move the lid.
8. 8. The appliance of Claim 7, wherein the support means is movable independently of the container and the lid transport means is responsive to relative movement between the support means and the container.
9. 9. The appliance of Claim 8, wherein the lid transport means is responsive to continued movement of the support means after movement of the container has ceased.
10. 10. The appliance of Claim 5, wherein the lid transport means moves the lid during initial movement of the container upon opening and during final movement of the container upon closing.
11. 11. A cold-storage appliance including: an open-topped insulating container defining an external surface; an insulating lid adapted to close the open top of the container; a cooling means adapted to cool the interior of the container; and a structure supporting the container, the lid and the cooling means; wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afford access to its interior or to close the container, and wherein said movement of the container includes:

    a major component to open the container and afford access to its interior or to close the container ; and a minor component, transverse to the major component, to free the container from the lid at the beginning of said major component upon opening or to bring the container and the lid together at the end of said major component upon closing.
12. 12. The appliance of Claim 11, wherein the minor component takes place before the major component upon opening and after the major component upon closing.
13. 13. The appliance of Claim 11, wherein the minor component takes place during initial movement in the direction of the major component upon opening and during final movement in the direction of the major component upon closing.
14. 14. The appliance of any of Claims 11 to 13, comprising support means movable to support the container during the major component and container transport means between the support means and the container that responds to movement of the support means to effect the minor component.
15. 15. The appliance of Claim 14, wherein the support means is movable independently of the container and the container transport means is responsive to relative movement between the support means and the container.
16. 16. The appliance of Claim 15, wherein the container transport means is responsive to continued movement of the support means after the major component of movement of the container has been completed.
17. 17. The appliance of Claim 15 or Claim 16, wherein the container transport means includes a first part in fixed relation to the support means and a second part in fixed relation to the container, wherein relative movement between the parts accommodates said continued movement of the support means.
18. 18. The appliance of Claim 17, wherein said relative movement between the parts causes the minor component of movement of the container.
19. 19. The appliance of Claim 17 or Claim 18, wherein one part includes a ramp and the other part includes a ramp follower.
20. 20. The appliance of Claim 19, wherein the ramp is associated with stops or buffers to limit relative movement of the ramp follower.
21. 21. The appliance of Claim 19 or Claim 20, wherein the ramp follower is a wheel.
22. 22. The appliance of any of Claims 17 to 21, wherein the parts can be separated on removing the container from the support means.
23. 23. The appliance of any of Claims 14 to 22, wherein the support means is fixed to a stabilising mechanism to resist lateral sway of the container during the major component of movement.
24. 24. The appliance of Claim 23, wherein the stabilising mechanism includes pinions movable with the support means, the pinions being engaged with respective laterallyspaced racks extending in the direction of the major component.
25. 25. A cold-storage appliance including: an open-topped insulating container defining an external surface; an insulating lid adapted to close the open top of the container; a cooling means adapted to cool the interior of the container; and a structure supporting the container, the lid and the cooling means;

    wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afford access to its interior or to close the container, and wherein the external surface of the container is exposed to air above ambient temperature when the container is closed by the lid.
26. 26. A cold-storage container adapted to be stacked or otherwise grouped with other abutting containers, wherein the container has external formations shaped to define airflow channels around at least part of the container when the container is in such a group of abutting containers.
27. 27. The container of Claim 26 wherein some or all of the formations are defined by a cover of the container.
28. 28. The container of Claim 26 or Claim 27, wherein the formations include ribs or castellations or other combinations of projections and/or recesses on external surfaces of the container and/or the cover.
29. 29. The container of any of Claims 26 to 28, wherein the container or its cover has a part projecting sideways to abut a neighbouring container or a cover of such a container in a group.
30. 30. The container of Claim 29, wherein the abutting projecting part defines an airflow channel between opposed side walls and/or covers of the neighbouring containers.
31. 31. The container of any of Claims 27 to 30, wherein the covers of neighbouring containers co-operate to define a substantially flat and continuous support surface penetrated by airflow channels.
32. 32. The container of Claim 31 when appendant to Claim 30, wherein the cover overhangs at least one side wall of the container to serve as the abutting projecting part and airflow channels penetrating the support surface communicate with an airflow channel defined by the overhanging cover between opposed side walls of the

    neighbouring containers.
33. 33. A cold-storage appliance including a plurality of containers cooled by forced air cooling means and comprising a corresponding plurality of air circulation paths, one for each container, wherein the air circulation paths are segregated and vapour-sealed from each other but a common cooling means is shared by the air circulation paths.
34. 34. The appliance of Claim 33, wherein the air circulation paths are defined by ducts separated from one another by an insulating gap.
35. 35. The appliance of Claim 34, wherein the insulating gap is filled by air or an insulating material.
36. 36. The appliance of any of Claims 33 to 35, wherein separate defrost and drainage means, one for each air circulation path are associated with the common cooling means in each air circulation path.
37. 37. The appliance of Claim 36 when appendant to Claim 34 or Claim 35, wherein the drainage means comprises a drainage duct that runs through the insulating gap between air circulation paths.
38. 38. A cold-storage appliance including a major compressor and a minor compressor and switch or valve means responsive to cooling demands upon the appliance for switching cooling load between the compressors, such that the major compressor handles relatively high cooling demands and the minor compressor handles relatively low cooling demands.
39. 39. The appliance of Claim 38, wherein the major compressor and the minor compressor together handle relatively high cooling demands.
40. 40. The appliance of Claim 38 or Claim 39, wherein the compressors are in parallel.
41. 41. A cold-storage appliance including:

    at least one container ; a structure defining a vapour-salable container compartment from which the container can be withdrawn to open the container and afford access to its interior and to which the container can be returned to close the container for cold storage of any items within the container; and valve means communicating with the container compartment to admit air from outside the appliance when the container is being withdrawn from the container compartment, to expel air outside the appliance when the container is being returned to the container compartment, and to maintain a vapour seal with the container compartment when the container is within the container compartment.
42. 42. A cold-storage appliance including: at least one container; a structure defining a vapour-sealable container compartment from which the container can be withdrawn to open the container and afford access to its interior and to which the container can be returned to close the container for cold storage of any items within the container; and barrier means adapted to advance and to retract along the container compartment as the container is being withdrawn from and returned to the container compartment, while maintaining a vapour seal so as (i) to separate from the interior of the container air drawn into the container compartment by withdrawal of the container and (ii) to displace that air from the container compartment when the container is returned to the container compartment.
43. 43. The appliance of Claim 42, wherein the barrier means is a bellows extensible along and sealed to the surrounding walls of the container compartment.
44. 44. A vehicle-mountable freight container for transporting or storing bulk perishable items, the container having insulating walls defining an open top ; and an insulating cover adapted to close the open top and being movable or removable to afford access from above the container to its interior for loading or unloading the bulk perishable items.
45. 45. The container of Claim 44, further comprising a cooling means adapted to cool the interior of the container.
46. 46. The container of Claim 45, wherein the cooling means includes a refrigerator engine mounted to a side or end of the container.
47. 47. The container of Claim 46, wherein the cooling means includes a refrigerator engine that is removable from the container in modular fashion.
48. 48. The container of Claim 47 and having a removable cover, wherein the refrigerator engine is removable as a module with the removable cover.
49. 49. The container of any of Claims 44 to 48, further comprising an upwardly-facing seal around the open top of the container.
50. 50. A vehicle for transporting or storing bulk perishable items in the vehicle-mountable freight container of any of Claims 44 to 49 and having means for adjusting the height of the open top of the container relative to the ground supporting the vehicle.
51. 51. A refrigerated handling facility for use in the transport or storage of bulk perishable items, comprising a downwardly-opening hatch co-operable with the open top of the container of any of Claims 44 to 49.
52. 52. The handling facility of Claim 51, wherein the hatch is defined in a structure overhanging a loading bay capable of receiving a vehicle carrying the container.
53. 53. The handling facility of Claim 52, further including a hoist for removing the cover of the container before the vehicle enters the loading bay with the open-topped container.
54. 54. The handling facility of any of Claims 51 to 53, further including a downwardly-facing seal around the hatch that is co-operable with the container around its open top.
55. 55. The handling facility of any of Claims 51 to 54, further including a hatch cover movable to close the hatch.
56. 56. The handling facility of any of Claims 51 to 55, further including a crane movable over the open hatch to access the interior of an open-topped container below the hatch.
57. 57. The handling facility of any of Claims 51 to 56, further including means below the hatch for raising or lowering a vehicle or container beneath the hatch.
58. 58. A system for transporting or storing bulk perishable items, comprising a handling facility as defined in any of Claims 51 to 57 in combination with a container as defined in any of Claims 44 to 49 and/or a vehicle as defined in Claim 50.
59. 59. A method of handling bulk perishable items, comprising storing those items in opentopped insulated freight containers within a refrigerated storage facility and subsequently transporting the containers after attaching or closing an insulated cover to close the open top.
60. 60. A method of handling bulk perishable items, comprising transporting those items in open-topped insulated freight containers having an insulated cover to close the open top, opening or removing the cover to open the top, and accessing the interior of the opentopped container from above to load and/or unload the items from the container.
61. 61. The method of Claim 60, comprising moving the open-topped container under a downwardly-opening hatch leading to a refrigerated handling facility, and loading and/or

    unloading the items through the hatch.
62. 62. The method of Claim 61, further comprising sealing around the container and the hatch.
63. 63. A cold-storage appliance including at least one container and a cooling means adapted to cool the interior of the container, wherein the cooling means is adjustable to maintain temperatures within the container either side of zero Celsius, selectably to freeze or to chill contents placed therein.
64. 64. The appliance of Claim 63, including a plurality of containers and said cooling means being independently controllable such that different temperatures can be selected in different containers.
65. 65. The appliance of Claim 64, including means for selectably designating each container as either a chiller or a freezer to vary the ratio of chilled to frozen storage space in the appliance.