WO2002022993A1

WO2002022993A1 - Freight handling and storage

Info

Publication number: WO2002022993A1
Application number: PCT/GB2001/004117
Authority: WO
Inventors: Ian David Wood
Original assignee: Applied Design And Engineering Limited
Priority date: 2000-09-13
Filing date: 2001-09-13
Publication date: 2002-03-21
Also published as: AU2001286110A1

Abstract

A handling facility for use in the transport or storage of perishable items, preferably under refrigerated conditions. The facility comprises a structure defining a downwardly-opening hatch (320) co-operable with an open top of a vehicle-mountable freight container (302) for transporting or storing perishable items, to afford access from above the container (302) to its interior for loading or unloading the perishable items. A method of handling perishable items comprises transporting those items in an open-topped freight container (302) having a cover (304) to close the open top, opening or removing the cover (304) to open the top before or after aligning the top with a downwardly-opening hatch (320) in a handling facility, and accessing the interior of the open-topped container (302) from above to load and/or unload the items from the container (302).

Description

FREIGHT HANDLING AND STORAGE

This invention relates to the art of freight handling and storage, including means for storing and transporting foodstuffs, chemicals, medical or biological specimens and other perishable items in chilled or frozen conditions.

The invention develops and adds to various features of the Inventor's co-pending International Patent Application No. PCT/GB00/03521, the contents of which are incorporated herein by reference. PCT/GB00/03521 has now been published as WO 01 /20237 and has been assigned to the present Applicant.

Briefly to recap the introduction of WO 01/20237, 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, modern 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.

These challenges of cold storage extend beyond cold storage appliances into the field of cold storage installations such as refrigerated warehouses and similar facilities. Here, the aims of energy efficiency and avoiding cross-contamination are all the more important. Put simply, the high energy consumption typical of such facilities gives more scope for an inefficient installation to waste energy. Moreover, the sheer quantity of perishable items held in a facility such as a refrigerated warehouse and their many different origins and destinations mean that the consequences of cross-contamination could be very far- reaching. Indeed, cross-contamination of perishable items with infectious agents within a warehouse could lead to a wide-ranging public health hazard and require closure and disinfection of the warehouse and destruction of its contents, at possibly massive cost.

In existing cold storage facilities such as refrigerated warehouses, perishable items such as foodstuffs are typically stacked within a large refrigerated storage space in which cold air circulates to maintain the desired temperature, which may be above or below freezing. To carry heat away from the stored items, the cold air is circulated within the storage space either by impellers in a forced-air system or, more simply, by convection. This flow of air makes it difficult to segregate different types of perishable items to avoid cross- contamination: measures designed to promote the circulation of air needed for cooling also promote the circulation of moisture, enzymes, spores and harmful bacteria entrained by that airflow.

Energy efficiency and avoidance of contamination make it desirable to keep cold air in and warm contaminated ambient air out, and thus to seal the refrigerated storage space of a warehouse from its surroundings. However, no matter how well sealed the storage space may be, at least one opening such as a doorway must be available for the transfer of perishable items into and out of that space. Whilst that opening will often be provided with a door or other movable closure to maintain the seal while closed, such a closure must be moved into an open position from time to time to allow access to the storage space by -vehicles and/or warehouse personnel. When that happens, cold air spills from the storage space through the opening. The outgoing cold air creates a pressure drop which draws in warm moist ambient air.

This ingress of ambient air reduces energy efficiency because the warm incoming air must be cooled, a task which is made more difficult by the latent heat of water vapour carried by that air. The ingress of ambient air also increases the possibility of contamination because the incoming air carries moisture and contaminants with it. Once in the storage space, the warm, moist and contaminated incoming air can circulate as freely as the colder, drier and cleaner treated air that is supposed to be there. The water vapour in the incoming air also increases the likelihood of icing problems within the storage space.

Efforts to minimise the exchange of cold air and warm ambient air may involve repeatedly opening and closing a door or other closure as vehicles such as forklift trucks and/or warehouse personnel travel back and forth through the opening leading to and from the storage space. However, this is impractical and ineffective when there is a substantial flow of vehicular and human traffic through the opening, as may be the case when loading or unloading a goods vehicle parked outside the warehouse. Then, vehicles and personnel shuttle back and forth through the opening at such a rate that the door is open for most if not all of the time.

An auxiliary closure such as a drive-through curtain of flexible transparent vertically- hanging strips may be employed to screen the opening in such circumstances, but this still cannot prevent substantial loss of cold air and ingress of warm ambient air. This is a particular problem because operators tend to regard an auxiliary closure such as a curtain as an adequate substitute for a main closure such as a door - which in sealing terms it is not - and so do not close the main closure as often or as carefully as they should. Also, closures such as doors may easily be damaged by impact with passing traffic; such damage can prejudice their ability to maintain an effective vapour seal when closed.

All of the above drawbacks also apply to the smaller mobile storage spaces defined by goods containers or other load bays of refrigerated goods vehicles. Typically, large vertically-hinged doors on a vertical rear or side face of the container or load bay are opened to gain access to the perishable items within. As soon as those doors are opened, much of the cold air in the storage space spills out and is replaced by ambient air, with all of the problems that this entails.

Even if a way can be found to prevent the exchange of air with and from a storage space while allowing access to that storage space when transferring perishable items, there is every likelihood that those items will be exposed to ambient air in transit between such storage spaces, such as when loading or unloading a goods vehicle parked outside a warehouse. As vehicles and personnel shuttle back and forth between the vehicle and the warehouse carrying the perishable items between those storage spaces, contaminants in the ambient air can settle upon the items, which then introduce those contaminants into the storage space to which those items are being sent. Also, water vapour in the ambient air can condense and possibly freeze upon the exposed items, causing icing problems. Further, if the transit time between the storage spaces is particularly long and the ambient air is very warm, there is a risk that the perishable items will overheat and, for example, partially defrost. This introduces a risk of deterioration that, in the case of foodstuffs, may present a health risk when those foodstuffs are eventually sold and consumed. It is of course possible for a mobile storage space such as a refrigerated goods vehicle to be driven or otherwise moved into a fixed storage space such as a refrigerated warehouse. This ensures that perishable items are not exposed to ambient air while being transferred from one storage space to the other. However, the vehicle still has to be driven through an opening leading to the fixed storage space, which opening militates against a fully sealed environment within that space. Also, the vehicle itself will carry contaminants into the fixed storage space, or will produce contaminants such as exhaust fumes

It is also possible for a mobile storage space such as a refrigerated goods vehicle to be coupled externally to a fixed storage space such as a refrigerated warehouse, so as to ensure as far as possible that perishable items are not exposed to ambient air while being transferred from one storage space to the other. Particular reference is made at this point to the American Society of Heating, Refrigerating and Air-Conditioning Engineers' 1998 ASHRAE Refrigeration Handbook, the disclosure of which is incorporated herein by reference, and especially to Chapter 13 thereof entitled REFRIGERATED FACILITY DESIGN.

The introduction to Chapter 13 of the ASHRAE Refrigeration Handbook specifies that a refrigerated facility is any building or section of a building that achieves controlled storage conditions using refrigeration. Two basic storage facilities are (1) coolers that protect commodities at temperatures usually above 32°F (zero Celsius) and (2) low- temperature rooms (freezers) operating under 32°F to prevent spoilage or to maintain or extend product life.

Chapter 13 of the ASHRAE Refrigeration Handbook has sub-headings entitled Initial Building Considerations, Building Design, Specialized Storage Facilities, Construction Methods, Refrigeration Systems, Insulation Techniques, Applying Insulation and Other Considerations. It includes plan and side views of typical refrigerated facilities, which include at least one intermediate-temperature refrigerated shipping dock. The dock is a refrigerated anteroom to the cold storage space that is necessary to maintain temperature control during all steps of product handling, especially in humid and warm climates. The dock has insulated inner doors that can be opened to access the storage space, and insulated outer doors having cushion-closure seals disposed around the doors to fit around a corresponding opening such as a rear doorway of a goods vehicle reversed against the outer doorway. This reduces the infiltration of outside air, although such infiltration of air cannot be wholly eliminated.

Thus, the dock performs the function of an airlock between ambient air and the cold treated storage air. In order for the airlock to work effectively, only an inner or an outer door can be open at any one time. With an outer door open and a goods vehicle in position, items can be unloaded and stored temporarily in the dock. The inner door remains closed during unloading. Then the outer door is closed, the inner door is opened and the items are transferred from the dock to the cold storage space. The process is reversed to load a goods vehicle.

Numerous repetitive movements of fork lift trucks or other vehicles are involved during loading and unloading, particularly in view of the limited manoeuvering space and the discrete packaging of the various loads, usually on several pallets. Furthermore, those journeys may be long: side docks such as those illustrated in the ASHRAE Refrigeration Handbook may require fork lift trucks repeatedly to travel from one side of the facility to the other and back again.

The goods vehicles themselves must also be carefully aligned with the outer doors of the facility and this can involve painstaking manoeuvering on a turning apron beside the facility. This manoeuvering takes valuable time and adds to pollution from exhaust gases. Moreover, this process must be repeated when it is desired to load a vehicle that has just been unloaded: the ASHRAE Refrigeration Handbook recommends the use of two separate crews at respective separate locations, each served by a different outer door with which the goods vehicle must mate or couple.

The dock is usually warmer than the cold storage space, for example to ensure the comfort and safety of those working there and to reduce condensation on vehicles and equipment working within the dock. This means that the storage space will still be warmed whenever the inner door is opened. Moreover, contaminants that happen to enter the dock through the outer door can subsequently enter the storage space from the dock through the inner door.

To allow room for the temporary storage of items and for movement of personnel and vehicles within the dock, the dock must be of substantial size. This increases the cost of the facility and reduces the cold storage space available for a given building cost or within a given site area. It will be noted in this respect that the dock is typically beside the building and so adds greatly to its land usage without contributing any long-term cold storage space. Further valuable land is devoted to the turning apron on which goods vehicles have to turn round and manoeuvre, as if in a cul-de-sac.

The ASHRAE Refrigeration Handbook also explains the design challenges involved in the floors and doors of refrigerated facilities. Floors must usually be designed to prevent under-floor ice formation, which causes 'heaving' of floors and columns due to expansion. For example, to prevent heaving, the soil or fill under the insulation that underlies the floor can be heated by a network of warm air ducts, electric heating elements or pipes through which a warm liquid is circulated. This increases the building cost, complexity and running cost of the facility. Existing refrigerated storage facilities also require expensive design and monitoring measures to allow for thermal expansion and contraction of the building itself.

Similarly, door installations need to be of high quality and are expensive to build and to maintain: to keep an effective seal, they need to compress their peripheral seals evenly around the door opening, but are susceptible to damage caused by collision with a carelessly-driven forklift truck. Guards and proximity alarms may be provided to reduce this risk, but they involve further cost and introduce further complexity of operation and maintenance. The alternative of monitoring and repairing damage to a door when that damage happens is similarly costly.

It is against this background that the present invention has been devised. From one aspect, the invention contemplates a handling facility for use in the transport or storage of perishable items, comprising a structure defining a downwardly-opening hatch co-operable with an open top of a vehicle-mountable freight container for transporting or storing perishable items, to afford access from above the container to its interior for loading or unloading the perishable items.

Advantageously, the handling facility of the invention further includes a crane movable over the open hatch to access the interior of an open-topped container below the hatch. This advantage is maximised if the container defines a substantially horizontal load area and the hatch opening, when co-operating with the open top of the container, affords access to substantially all of that load area by lifting tackle depending from a jib or gantry of the crane.

The structure defining the hatch suitably overhangs or is otherwise situated over a loading bay capable of receiving a vehicle carrying the container. The handling facility may further include a hoist for moving or removing the cover of the container either before the vehicle enters the loading bay with the open-topped container, or preferably immediately before or after the container is aligned with and optionally sealed to the hatch. To speed the process, the hoist is advantageously capable of moving the cover forwardly with respect to a direction of movement of the vehicle through the facility.

Advantageously, to minimise loss of cold air and the risk of cross-contamination, a seal is disposed between the open top of the container and the structure around the hatch. That seal may,, for example, be a downwardly-facing seal around the hatch that is co-operable with the container around its open top. The seal may further include an inwardly-facing element to seal around the sides of the container. Means may be provided below the hatch for raising or lowering a vehicle or container beneath the hatch, to make and break a seal.

To retain cold air, it is preferred that the handling facility further includes a hatch cover movable to close the hatch.

The handing facility of the invention advantageously includes drive means for driving the vehicle to and from the hatch, independently of the vehicle powertrain. This reduces pollution from the vehicle's engine. The drive means may for example includes a cable for pulling the vehicle below the hatch.

For optimum use of land, the structure defining the hatch is preferably supported above a path along which vehicles can move through the facility. To speed the process and avoid land usage normally devoted to turning aprons, vehicles preferably move through the facility substantially uni-directionally along the path. Elegantly, a container-unloading hatch can be situated upstream of a container-loading hatch with respect to the direction of movement along the path. Thus, a container on a vehicle moving along the path can be filled immediately after being emptied.

To minimise the length of journeys travelled by fork lift trucks or lifting tackle within the handling facility, the hatch is advantageously substantially centrally situated with respect to a storage area of the facility.

The invention extends to a handling system for storing or transporting perishable items, comprising a handling facility as defined above and at least one vehicle-mountable freight container for transporting or storing perishable items, the container having walls, an open top and a cover adapted to close the open top, the cover being movable or removable to afford access from above the container to its interior for loading or unloading the perishable items. The upper edges of the walls of the container can together define the periphery of the open top.

The container may further comprise a cooling means adapted to cool the interior of the container. That cooling means preferably includes a refrigerator engine mounted to a side or end of the container, and that refrigerator engine is advantageously 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 being part of the handling system 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 contemplates a vehicle for transporting or storing 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 system of the invention, and a container of the invention, preferably includes a platform movable within the container for supporting perishable items, the platform being removable from the container through the open top while carrying the items. The platform preferably defines a load-bearing floor of the container. The system may further include wheels, castors or a carriage for supporting and moving the platform within the handling facility.

For ease of attaching lifting tackle and lifting a load carried by the platform, the platform is preferably linked to the cover of the container to be suspended from the cover when the cover is lifted from the container.

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

The methods of the invention suitably comprise moving the cover forwardly with respect to a direction of movement of the container through the handling facility. They preferably involve moving the container through the handling facility, unloading the container at a first hatch and loading the container at a second hatch downstream of the first hatch with respect to the direction of movement of the container. For example, containers can be moved from one hatch to the next on vehicles driven externally through the handling facility.

The method preferably comprising lifting items out of the container on a platform carrying a plurality of discrete loads of the items and moving the items within the handling facility while on the platform. Advantageously in that event, the method may further comprise storing the items within the handling facility while on the platform.

Whilst preferred embodiments of the invention mainly contemplate the storage and transport of perishable items in discrete form, it is also possible for the invention to be applied to the storage and transport of bulk materials in refrigerated conditions or otherwise. For the sake of brevity therefore, references to 'items' in this specification should be taken to include bulk materials unless the context requires otherwise.

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:

Figures 1(a), 1(b) and 1(c) are schematic views of the invention applied to storage in a cold store and commercial transport in a refrigerated vehicle, and correspond to Figures 20(a), 20(b) and 20(c) of PCT/GB00/03521, now published as WO 01/20237;

Figure 2 is a schematic sectional side view of the interior of a container shown on a truck in Figure 1(a);

Figure 3 is a schematic sectional side view of an alternative container arrangement better suited to stacking;

Figures 4(a), 4(b) and 4(c) are schematic side views of the truck of Figure 1(a) being loaded or unloaded at a cold storage facility;

Figure 5 is a side view of another cold storage facility in accordance with the invention;

Figures 6(a), 6(b), 6(c) and 6(d) are a sequence of schematic side views of a truck being loaded or unloaded at the cold storage facility of Figure 5;

Figure 7 is a schematic side view of a truck being loaded or unloaded at the cold storage facility of Figure 5, in which perishable items are hoisted as a single lift;

Figure 8 is a schematic side view of a truck being loaded or unloaded at the cold storage facility of Figure 5, showing alternative seal and cover removal arrangements; and

Figure 9 is a schematic side view of a truck being loaded or unloaded at the cold storage facility of Figure 5, showing the alternative seal and cover removal arrangements of Figure 8 and having an alternative single lift arrangement to that shown in Figure 7.

Figures 1(a), 1(b) and 1(c) are schematic views of the invention applied to storage in a cold store and commercial transport in a refrigerated vehicle. Figure 1(a) shows a vehicle 300 carrying a standard-size refrigerated storage container 302: this 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 1(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 or the storage facility. 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 1(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 2 shows, materials 308 can be stacked within the container 302 on pallets 314, each having lifting tackles 316 for top lifting as shown in Figure 1(b).

Whilst the containers 302 shown in Figures 1(a), 1(b) and 1(c) and in Figure 2 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 3 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 3, the refrigerator engine 306 can be removed with the cover 304 as a unit, although this is optional.

Figures 4(a), 4(b) and 4(c) show the truck 300 of Figure 1(a) being loaded or unloaded at a specially-adapted cold storage facility 316. Firstly, in Figure 4(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 4(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 4(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 4(b) and 4(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 5 of the drawings, the invention contemplates a bottom-loading cold storage facility 332 in which the dock area of the prior art can be entirely eliminated and instead of a pair of inner and outer doors only a single hatch cover is required in the floor. Items can therefore be unloaded directly into the cold storage space 334. In particular, it will be noted that the cold storage space 334 of the facility 332 is raised off the ground and supported by columns 336, to allow trucks 300, trains or other vehicles to pass underneath.

The layout of the invention has several significant advantages over the prior art. For example, large areas of land are saved because docks are not required and shipping, receiving, transport and loading takes place underneath the cold storage space 334. Moreover, the underside of the raised storage space 334 is exposed to ambient air and therefore there is no need for heating to prevent ground heaving. Also, raising the storage space 334 off the ground on columns 336 makes it much easier to cater for contraction and expansion at joints of the building structure.

There are also advantages in terms of vehicle movement. A bottom-loading access hatch 330 can be located substantially centrally with respect to the cold storage space 334 and so halve the maximum length of journeys undertaken by fork lift trucks. Furthermore, bottom loading allows a 'drive through' transport system, instead of a cul-de-sac turning apron. Consequently, bottom loading is more efficient and requires less land because trucks 300 do not need to turn around or manoeuvre to the extent suffered by the prior art.

In the invention, the two separate loading crews contemplated in the ASHRAE Refrigeration Handbook are not required; instead, goods can be received and dispatched in one operation. However, trucks 300 can unload at one receiving point and drive or otherwise move forward to another more convenient dispatch point for re-loading. It is therefore possible to have a dedicated goods-in hatch 330A and a dedicated goods-out hatch 33 OB downstream of the goods-in hatch 330A, as Figure 5 shows, with each hatch 330 being located to best advantage with respect to the floor plan of the cold storage space 334. Thus, a truck 300 can be unloaded at the goods-in hatch 330A, advanced to the goods-out hatch 330B and immediately re-lqaded, without further manoeuvering.

A problem of driving trucks 300 under the cold storage space 334 could be an accumulation of exhaust gases which may contaminate loads or migrate into the storage space 334. This problem can be solved by moving the trucks 300 under external power, for example by placing the trucks 300 on a conveyor system that runs under the cold storage space 334 or by pulling them under that space 334 with a cable system or on carriages. It would also be possible to rely upon natural ventilation or to blow air through the gap beneath the cold storage space 334 to purge exhaust gases.

The following describes an automatic process (which could equally be carried out manually) that uses a cable system to move trucks 300 through the cold storage facility 332 of Figure 5, with reference to Figures 6(a), 6(b), 6(c) and 6(d). The trucks 300 are shown travelling in the. opposite direction to Figure 5 but the facility 332 is the same.

Firstly, on arrival at the cold storage facility 332, a truck 300 is connected to a cable guidance system 338 which pulls the truck 300 under the cold storage space 334 to bring the top of its container 302 into alignment with a goods-in hatch 330A, as shown in Figure 6(a). Precise location can be ensured by optical sensors (not shown) that feed back positional information to the cable guidance system 338 to bring the truck 300 to an optimum position. The cover 304 of the container 302 is then released and moved by a hoist (not shown) to a position forward of the truck 300, whereupon the container 302 is engaged to seals 328 around the goods-in hatch 330A either by being raised towards the seals 328 or the seals 328 extending down toward the truck 300, as shown in Figure 6(b). The goods-in hatch 330A is then opened and the palletised loads 308 within the container 302 are hoisted into the cold storage space 334, as shown in Figure 6(c). Finally, the cover 324 of the goods-in hatch 330A is replaced, the seal 328 is disengaged from the container 302, and the truck 300 is moved forward by the cable system 332 to receive the cover 304 of the container 302, as shown in Figure 6(d). The truck 300 and container 302 can then leave the cold storage facility 332 or be moved to the downstream goods-out hatch 330B where a similar process would be repeated to load the container 302.

The optional single-lift arrangement shown in Figure 7 further addresses the problem that fork lift trucks have to make many movements to complete the process of loading and unloading a truck. In the arrangement of Figure 7, the floor of a specially-adapted freight container 302 provides a removable insulated structural platform 340 on which perishable items 308 are placed. An angle plate (not shown) is provided around the bottom sides of the container 302 to receive the platform 340. The platform 340 sits on the horizontal flange of the angle plate and seals against it.

The interface between the container 302 and truck 300 may contain a seal and blanking plate (not shown) to prevent cold air escaping as the platform 340 is lifted. Alternatively, a peripheral seal could be provided between the perimeter of the platform 340 and the inside of the container 302, as the platform 340 moves within the walls of the container 302 like a piston.

The platform 340 can be hoisted into the cold storage space 334 by the crane 310 and slung to one side, where it can then be unloaded, checked, and reloaded, all at the ideal storage temperature and with no time limit. If needs be, a spare platform 340 can be returned to the container 302 of the truck 300 and the hatch 330 closed and sealed. The whole operation of loading or unloading can therefore take a matter of minutes rather than hours, freeing the truck 300 to go back on the road and earn money for its operator. Platforms 340 could be provided with, or placed on, wheels, castors or carriages to make them mobile, thereby assisting stocking or dispatching goods more effectively. By way of illustration, say the items 308 on one platform 340 are to be stacked in racking at one side of the cold storage space 334 and the loading hatch 330 being used is at the other side of the storage space 334. Normally in such circumstances a fork lift truck would have to make the journey repeatedly from one side of the storage space 334 to the other, and back again, for each pallet of items 308. However, a mobile platform 340 could be towed by a fork lift truck across the storage space 334 in one initial operation and then unloaded locally. Additionally, it is possible not to unload the platform 340 but instead to place it with its load 308 directly onto the racking system.

Alternative cover removal and seal arrangements illustrated in Figures 8 and 9 of the drawings involve sealing around the upper sides of the container 302. The seal 328 is vertically extendable down from the structure of the cold storage space 334 as before but the vertical skirt of the seal 328 has inwardly-facing extensions 342 that seal against the sides of the container 302. The skirt portion of the seal 328 must provide sufficient clearance that the cover 304 of the container can be removed by hoisting that cover 304 into the cold storage space 334 as shown and then unloading or loading the open-topped container 302 as appropriate. The advantage of this system is that the items are not exposed to ambient air during the delivery or dispatch process.

Finally, and referring specifically to Figure 9 of the drawings, this shows a development of the single-lift arrangement of Figure 7 in which lifting tackle of a crane 310 is simply attached to the lid 304 of a container 302 below the hatch 330. Lifting loads are then transmitted to the platform 340 through straps 344 or other tensile members. Like the arrangement of Figure 8, the provision to lift the cover 304 of the container 302 into the cold storage space 334 means that the vertical skirt of the seal 328 has inwardly-facing extensions 342 that seal against the sides of the container 302.

As the ASHRAE Refrigeration Handbook makes clear, the design of door systems is a major aspect of the design of existing cold storage facilities. Horizontal swing doors and sliding doors do not lend themselves to simple sealing arrangements. Additionally, their seals and/or sealing surfaces are subject to mechanical damage from fork lift tucks passing through doorways.

The hatch covers contemplated by the invention could be hinged lid, horizontal slide or interleaved doors as best suited to the process. Situating the hatch cover in the bottom of the storage space, where it overlies and overlaps the edges of the hatch, has the natural advantage that the weight of the cover and internal air pressure help to seal the hatch. A further advantage is that loading or unloading by hoist allows more accurate and reliable positioning than fork lift trucks, which helps to avoid clashes with seals and seal surfaces. Interlock systems may be provided to ensure avoidance of clashes. This, together with having a single access as opposed to the double door arrangement typical of the prior art, significantly reduces seal failure and door maintenance.

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 biohazards.

It will be apparent to those skilled in the art that many of the handling techniques described herein are not restricted to cold storage but could be applied to any containerised storage facility. The bottom-loading storage system has special benefits in the art of cold storage but represents a fundamental and beneficial change to known goods handling processes in general.

Many variations are possible in addition to those already mentioned. For example, once the cover and optional platform have been removed from the container, the sides of the container may be demountable so that the four sides, cover, platform and bottom of the container can be transported as a layered 'flat pack' to save space.

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 invention. In interpreting the invention, 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

1. A handling facility for use in the transport or storage of perishable items, comprising a structure defining a downwardly-opening hatch co-operable with an open top of a vehicle- mountable freight container for transporting or storing perishable items, to afford access from above the container to its interior for loading or unloading the perishable items.

2. The handling facility of Claim 1, further including a crane movable over the open hatch to access the interior of an open-topped container below the hatch.

3. The handling facility of Claim 2, wherein the container defines a substantially horizontal load area and the hatch opening, when co-operating with the open top of the container, affords access to substantially all of that load area by lifting tackle depending from a jib or gantry of the crane.

4. The handling facility of any preceding Claim, wherein the structure defining the hatch is situated over a loading bay capable of receiving a vehicle carrying the container.

5. The handling facility of Claim 4, further including a hoist for moving or removing the cover of the container before the open-topped container co-operates with the hatch opening.

6. The handling facility of Claim 5, wherein the hoist is capable of moving the cover forwardly with respect to a direction of movement of the vehicle through the facility.

7. The handling facility of any preceding Claim, further including a seal between the open top of the container and the structure around the hatch.

8. The handling facility of Claim 7, wherein the seal is a downwardly-facing seal around the hatch that is co-operable with the container around its open top.

9. The handling facility of Claim 8, wherein the seal has an inwardly-facing element to seal around the sides of the container.

10. The handling facility of any preceding Claim, further including a hatch cover movable to close the hatch.

11. The handling facility of any preceding Claim, further including means below the hatch for raising or lowering a vehicle or container beneath the hatch.

12. The handling facility of Claim 11 when appendant to any of Claims 7 to 9, wherein the vehicle or container is raised to make the seal.

13. The handing facility of any preceding claim and including drive means for driving the vehicle to and from the hatch, independently of the vehicle powertrain.

14. The handling facility of Claim 13 , wherein the drive means includes a cable for pulling the vehicle below the hatch.

15. The handling facility of any preceding Claim, wherein the structure is supported above a path along which vehicles can move through the facility.

16. The handling facility of Claim 14, wherein vehicles can move through the facility substantially uni-directionally along the path.

17. The handling facility of Claim 16 and including a container-unloading hatch upstream of a container-loading hatch with respect to the direction of movement along the path.

18. The handing facility of any preceding Claim, wherein the hatch is substantially centrally situated with respect to a storage area of the facility.

19. A handling system for storing or transporting perishable items, comprising a handling facility as defined in any preceding Claim and at least one vehicle-mountable freight container for transporting or storing perishable items, the container having walls, an open top and a cover adapted to close the open top, the cover being movable or removable to afford access from above the container to its interior for loading or unloading the perishable items.

20. The system of Claim 19 and being adapted for storing or transporting perishable items under refrigerated conditions, wherein the container has insulating walls and an insulating cover adapted to close the open top.

21. The system of Claim 19 or Claim 20, wherein upper edges of the walls of the container together define the periphery of the open top.

22. The system of any of Claims 19 to 21, wherein the container further comprises a cooling means adapted to cool the interior of the container.

23. The system of Claim 22, wherein the cooling means includes a refrigerator engine mounted to a side or end of the container.

24. The system of Claim 23, wherein the cooling means includes a refrigerator engine that is removable from the container in modular fashion.

25. The system of Claim 24, wherein the container has a removable cover and the refrigerator engine is removable as a module with the removable cover.

26. The system of any of Claims 19 to 25, wherein the container further comprises an upwardly-facing seal around the open top of the container.

27. The system of any of Claims 19 to 26, further comprising a vehicle for transporting the container and having means for adjusting the height of the open top of the container relative to a surface supporting the vehicle.

28. The system of any of Claims 19 to 27 and including a platform movable within the container for supporting the items, the platform being removable from the container through the open top while carrying the items.

29. The system of Claim 28, wherein the platform defines a load-bearing floor of the container.

30. The system of Claim 28 or Claim 29, further including wheels, castors or a carriage for supporting and moving the platform within the handling facility.

31. The system of any of Claims 28 to 30, wherein the platform is linked to the cover of the container to be suspended from the cover when the cover is lifted from the container.

32. An opening-top container for use with the handling facility of any of Claims 1 to 18 or in the handling system of any of Claims 19 to 31, including a platform movable within the container for supporting perishable items, the platform being removable from the container through the open top while carrying the items.

33. The container of Claim 32, wherein the platform defines a load-bearing floor of the container.

34. The container of Claim 32 or Claim 33, wherein the platform is linked to a cover of the container to be suspended from the cover when the cover is lifted from the container.

35. A method of handling 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.

36. A method of handling perishable items, comprising transporting those items in an open-topped freight container having a cover to close the open top, moving or removing the cover to open the top before or after aligning the top with a downwardly-opening hatch in a handling facility, and accessing the interior of the open-topped container from above to load and/or unload the items from the container.

37. The method of Claim 36, further comprising sealing between the container and a structure defining the hatch.

38. The method of Claim 36 or Claim 37, comprising moving the cover forwardly with respect to a direction of movement of the container through the handling facility.

39. The method of any of Claims 36 to 38, comprising moving the container through the handling facility, unloading the container at a first hatch and loading the container at a second hatch downstream of the first hatch with respect to the direction of movement of the container.

40. The method of Claim 39, wherein containers are moved from one hatch to the next on vehicles driven externally through the handling facility.

41. The method of any of Claims 36 to 40, comprising lifting items out of the container on a platform carrying a plurality of discrete loads of the items and moving the items within the handling facility while on the platform.

42. The method of Claim 41, further comprising storing the items within the handling facility while on the platform.

43. The method of any preceding Claim, comprising moving or removing the cover of the container through the hatch.