WO2004083058A1

WO2004083058A1 - Collapsible crate

Info

Publication number: WO2004083058A1
Application number: PCT/IE2004/000037
Authority: WO
Inventors: Thomas Patrick Kelly; Adrian Thomas; Duncan Mcinnes; Samuel Jordan
Original assignee: Aspen Investment (Corporation) Limited
Priority date: 2003-03-19
Filing date: 2004-03-19
Publication date: 2004-09-30
Also published as: IES20030200A2

Abstract

The invention provides a collapsible container (1) which can be adapted between an in-use mode in which the container is being used to contain produce, a storage mode in which the container is empty, the container comprising a base (2) having a plurality of sides and a corresponding number of side walls (4, 5, 6, 7), wherein when the container is in the in-use mode, the side walls extend upwardly from the base, generally perpendicular thereto, and when the container is in the storage mode, the side walls lay resting on each other, parallel to the base, with the lower most side wall resting on the base. Two of the side walls are held in position by the other two side walls when the container is in the in-use mode, by means of a plurality of hooks (41) provided along opposed edges of two of the side walls interengageable with a corresponding plurality of pins provided at corresponding locations on the other two side walls.

Description

COLLAPSIBLE CRATE

The present invention relates to containers and more particularly to containers for intermediate bulk containers, (TBC's).

When containers (also referred to as crates) carrying produce are shipped by airplane, ship or land vehicles, they require a considerable amount of space and this problem is exacerbated when the containers are intermediate bulk containers (LBC's). The cost involved in using this space can be justified when the containers are being delivered full of produce. The return of empty containers to the supplier, however, is where a lot of the cost involved in the overall process is incurred by the supplier. This is particularly pertinent when the containers contain produce which can be transported in bags that may be disposed of when the produce have been expelled. This method of transporting products, particularly liquid products is referred to as "box and bag" technology. In the United States, a large proportion of liquid produce such as tomato paste and orange juice is shipped from the West Coast to the East Coast using this "box and bag" technology. Wooden containers can be disassembled but parts can easily become separated from the unit when a large number of containers are involved, thus rendering the remaining parts of the container useless. It is also time consuming to assemble and disassemble non- connected parts of a container adding further expense to the overall haulage operation. Furthermore, wooden containers do not meet the health and safety standards in Europe and therefore an alternative container is required for the European market. There is clearly a need for a method of reducing the cost involved in returning empty containers to their supplier.

United States Specification No. 6 234 315 discloses a collapsible container including a base and four side panels with u-shaped links coupling the side panels to the base to enable the side panels to fold down over the base to a storage position from a use position where the side panels are interconnected and upstanding from the base. Each coupling means connecting each panel to the base is constructed and operates in the same manner as each other. Spring means bias a first link spigot located in a sleeve attached to the base, to retain a second link spigot in a saddle attached to the side panel. The panel is detached by applying counter effort to link body and spring to withdraw the second link spigot from saddle. The container of US 6234315 relies on slide bolts provided on two panels, engaging in holes for securing side panels together as well as hooks which engage with flanges on the panels.

United States Specification No. 6 415 938 discloses a container comprising a base and four side panels. A pair of opposed side panels are coupled to upstanding corner posts of the base and the other pair of panels are coupled to rails upstanding from the base, the couplings allow the panels to be moved between an upstanding condition where the panels are interlocked with each other and are held by retainers to the base and the rails, and a storage condition where the panels lie one on top of the other over the base. The couplings are through panel mounted track followers engaged in "L" shaped tracks in the corner posts and the rails respectively. First limbs of the "L" shaped tracks are open ended allowing sequential demounting of the panels from the base by passage of the track followers through the open ends of the tracks. Demounting of the panels coupled to the rails is normally prevented until the panels coupled to the posts have been demounted from the base.

European Patent Specification No. 1 043 239 discloses a container with collapsible sides, at least one side is provided with at least one pivotally mounted lock handle with a lock pin that can, while protruding from the side, be introduced into an opening in an abutting side, wherein the lock pin can, by turning of the lock handle, be caused to lockingly engage with the opening. The lock handle is pivotally mounted in such a manner that in this locking position as well as in its resting position in which the lock pin does not engage with the opening is situated substantially along the side, while in other positions it protrudes considerably from the side. The lock handle is provided with a spring mechanism that will, irrespective of the position of the lock handle, influence it with a force in a direction towards its locking and resting positions. Hinges (each the same standard type of hinge) connect the side walls to the base.

International Patent Application No. WO 97 31832 discloses a collapsible container comprising a four-sided base including a base pallet mounted detachably to a base frame supporting a base panel. First, second, third and fourth side walls are connected to the sides of the base by means of floating hinge assemblies in the form of stub axles located within upright channel formations. Each side wall is pivotable between an erect position in which it extends perpendicularly from the base and a stacked position in which it is substantially parallel to and overlies the base. The floating hinge assemblies allow the hinge or pivot point of each side wall to be raised prior to being folded down into the stacked position over the other side walls. A pair of lid halves are hinged to the uppermost edges of the first and second walls on floating hinges, which allow the lid halves to pivot to a collapsed position in which they are flush with the other surfaces of the first and second side walls. The container is typically an IBC bag-in-box-type container.

International Patent Application No. WO 02 074642 discloses a collapsible insulated freight container for transport of perishable goods comprising a pallet base with integral feet supports; a perimeter recess in the base along the inside of each perimeter wall. There is no coupling means disclosed in the specification of WO 02074642. Instead, the two end walls and two side walls inserted in the recess in the base and held in an erect state with an interlocking mechanism of a peg received within a socket of a bracket with socket; the walls can be placed horizontally within the perimeter walls of the base when in a collapsed state. The container also includes a lid with rubber seal and flange engageably positioned either on top of the walls when in the erect state or on top of the perimeter walls when in the collapsed state. The container is made of insulating reinforced foam sandwiched between two outer layers of fibreglass, high impact plastic or sheet metal.

United States Specification No. 6 029 839 discloses a collapsible container is provided adaptable for use on a standard industry pallet and which includes an option of utilizing a bottom discharge port. The container includes four wall frame members, each with a replaceable wall panel attached to the inside surface of each wall frame member so that when the panels are assembled there is a continuous plastic surface on the interior of the container thereby reducing contact of the metal parts of the frame members to corrosive chemicals and further reducing the possibility of tearing or puncturing a plastic inner liner inserted into the interior of the container. The wall frame members are assembled using a rounded post and inverted V notch connecting means positioned along the side edges of the wall frame members which reduces the possibility of snagging or tearing the plastic inner liner when inserting it into the interior of the container. A foam block floor may be optionally inserted into the interior of the container and includes a passageway extending from the bottom surface of the container to a side location of one of the wall frame members, while a 90° elbow is attached to the discharge port on the plastic inner liner and inserted through the passage way when installing the liner thereby providing a bottom discharge port for the container.

The present invention seeks to alleviate the disadvantages associated with existing collapsible containers of the type referred to above.

Accordingly, the present invention provides a collapsible container comprising a four- sided base, first, second, third and fourth side walls; a first hinge assembly for coupling the first and second side walls to the base and a second hinge assembly for coupling the third and fourth side walls to the base, said first hinge assembly and second hinge assembly allowing the first and second, third and fourth side walls, respectively, to be moved between an in-use mode in which the container is being used to contain produce and a storage mode in which the container is empty, wherein when the container is in the in-use mode, the side walls extend upwardly generally perpendicularly from the base, and when the container is in the storage mode, the side walls lay resting on each other, parallel to the base in a stacked arrangement, with the lowermost side wall resting on the base; wherein the container further comprises locking means for enabling at least one of the side walls to be interlocked with another side wall, to maintain the side walls in the upright position when the container is in the in-use mode so that, in use, the container is securely held together, the locking means comprising interengaging formations provided on corresponding locations of the side walls.

With the use of the collapsible container of the invention, the overall cost of a haulage operation can be reduced significantly due to the fact that the space required for the containers on the return journey is vastly reduced. This results in a more efficient overall transportation process for the supplier. The container of the invention has the advantage that it folds down to 1/5 (one fifth) to 1/3 (one third) of its in-use size when it has been folded down into the storage mode.

The side walls of the collapsible container are put under substantial outward pressure due to the products stored within the container and in order to maintain the products in a secure environment, the side walls of the container must be safely secured together when the container is full. The container of the present invention has the advantage that when it is in the in-use mode, two of the side walls are held securely in position by the other two side walls so as to provide the container with additional structural integrity and reduce the risk of produce contained therein, spilling out of the container.

Preferably, the first hinge assembly comprises a floating hinge assembly, the floating hinge assembly allowing respective pivot points of the first and second side walls to be raised upwardly and outwardly prior to being folded down into the stacked position over at least one of the other stacked side walls.

Conveniently, the first and second side walls are folded down into the stacked position on top of the third and fourth side walls, with the third side wall lying on the base.

Preferably, the second side wall is uppermost when folded down into the stacked position over the other side walls

The first floating hinge assembly ideally including sliding means arranged to allow the uppermost second side wall to be firstly moved upwardly in a plane perpendicular to the base and then moved outwardly in a plane parallel to the base, prior to being folded down into the stacked position.

Advantageously, the floating hinge assembly includes a pair of floating hinges and comprises a sliding means moveable in a generally "L" shaped slot. Preferably, the sliding means includes a pin. The pins of the floating hinges comprise rotatable bushings which extend the life of the pins by replacing sliding friction with a rolling friction between the pin and the generally "L" shaped slots. The inclusion of the bushings has the advantage that the bushings extend the life expectancy of the floating hinges.

Ideally, the second hinge assembly comprises a plurality of co-axial hinges.

Conveniently, the interengaging formations comprise a plurality of lock projections provided along at least one minor face of a side wall and a corresponding plurality of lock projections engaging means provided at corresponding locations on another side wall such that when the side walls are in the upright, in-use mode, the plurality of lock projections on one side wall can interengage in the corresponding plurality of lock projection engaging means on the other side wall.

Preferably, the lock projections are in the form of hooks and are provided along at least one of the minor faces of two side walls and the lock projections engaging means comprise hook engaging means.

Advantageously, the hooks are provided along both of the minor side faces of two side walls and the hook receiving means are provided at corresponding locations on the two other side walls, such that two of the side walls can be interlocked with the other two side walls.

Ideally, the hooks are generally J-shaped hooks. The generally J-shaped hooks are provided along both of the minor side faces of the third and fourth side walls and the hook receiving means are provided on corresponding locations along the first and second side walls.

Conveniently, the plurality of hook engaging means comprise pins provide along ends (in the transverse plane) of the side walls.

Alternatively, the plurality of hook engaging means comprise slots provided along the transverse ends of the side walls, the slots being apapted to receive and engage with the plurality of hooks. The hooks engage in the slots such that, in use, the weight of the side walls is borne by the hooks bearing down in the slot whereby, in use, the hinge assemblies (i.e. floating hinges and the series of co-axial hinges) do not have to carry the weight of the side walls. This has the advantage that the hinges are not subjected to compression stresses and can operate more efficiently and have a longer life span.

Ideally, the generally J-shaped hooks open upwardly towards the top of the container when the side walls carrying the hooks are in the upright, in-use mode. Preferably, the side walls, base and lid are designed to withstand high stress and strain values due to the weight of the containers when full of produce. The JJBC's may be stacked up to six containers high. When a container is full, each container can weigh up to 2 tonnes with an internal pressure of 6 psi. If the container contains concentrate, the container and its contents can be kept in cold storage for up to 6 months, stacked 6 containers high. The container of the invention has the advantage that it is able to withstand substantial forces, as containers must be able to support other containers, particularly the lowermost container in a stacked arrangement. Furthermore, the container of the invention is strong enough to resist bulging of frozen contents.

The container may include a detachable lid which extends across an open top of the container to seal it fully when the container is in the in-use mode. However, the lid is preferably attached using attachment means comprising steel wires or leather or fiber straps.

In a preferred embodiment, the lid includes a tamper evident seal to clearly show if the container has been opened so that users are made aware of any unauthorised access to the contents of the container.

In another arrangement the lid has an associated locking device. This locking device may incorporate an electronic release mechanism requiring an access code which is transmitted independently of the container. Thus, access to the contents is prohibited until an appropriate code is entered.

According to another aspect of the invention the container incorporates an inflatable compartment. This provides a number of distinct advantages over known containers, for example, the compartment may be inflated to facilitate discharge of container contents. In this case, a compartment may be provided in each side wall and also in the base. The compartments may also be partially inflated to protect delicate contents where appropriate.

In another aspect of the invention, the container incorporates elevation means for raising the container to a predetermined position to facilitate discharge of container contents.

Preferably the container incorporates a liquid draining means. This draining means may be provided as a tap, access pipe or indeed as a connector formed for complementary engagement with a pump or other discharge mechanism. For example, the connector may be formed for engagement with a discharge outlet on a tractor, thus, if the container is used to transport material intended for spreading by tractor the container may be simply mounted on the tractor. The use of a draining port reduces the amount of litter such as seed and fertiliser bags scattered around farms. The sealed bags in the container also remove any possibility of the fertiliser clumping together into unworkable lumps as a result of exposure to the elements.

In a further embodiment of the invention, heating and cooling elements may be located on the base of the container. This allows material such as animal fat or dairy products to be maintained at a desired temperature during transportation and storage.

Preferably, the base comprises a three dimensional frame construction having a series of hollows and crossbars. The base is cast from a suitable material, for example, a magnesium alloy, which allows the weight of the base to be minimised whilst retaining the strength of the construction. This construction of the container has the advantage that the container involves less complex manufacturing processes and is therefore less expensive to produce. Also the container of the invention is easily and safely operated between the storage and in-use modes.

The container of the invention will now be described more particularly with reference to the accompanying drawings in which is shown one embodiment of the container of the invention.

In the drawings:

Figure 1 is a perspective view of the container in a first embodiment of the present invention, shown in the in-use mode with the side walls upstanding from the base and with the lid positioned on the side walls;

Figure 2 is a perspective view of the container of Figure 1 but with the lid removed; Figure 3 is a perspective view of the container in the first embodiment, showing the first side wall and second side wall being moved upwardly and outwardly so as to disengage the first and second side walls from the third and fourth side walls;

Figure 4 is a perspective view of the container in the first embodiment, showing the third side wall and the fourth side wall lying horizontally, parallel with the base and located within the side struts of the base (the third side wall being located underneath the fourth side wall in this drawing);

Figure 5 is a perspective view of the container in the first embodiment, showing the first side wall lowered into a horizontal position in which it is lying on top of the fourth side wall;

Figure 6 is a perspective view of the container in the first embodiment, with the second side wall lowered into a horizontal position in which it is lying on top of the first side wall, so that in this position all of the side walls are arranged horizontally on top of each other in a storage position and the uppermost side wall (i.e. the second side wall) laying aligned with the upper edge of the side struts of the base so that the side walls in this arrangement do not extend proud of the side struts of the base;

Figure 7 is a perspective view of the container of Figure 6 but with a lid secured over the collapsed side walls, all of which are lying parallel to the base;

Figure 8 is a side view of the first side wall and the fourth side wall in the relative position shown in Figure 3.

Figure 9 is a side view of the first side wall and fourth side wall in the relative position shown in Figure 4;

Figure 10 is a perspective view of the third side wall and the fourth side wall in an upstanding in-use position, with the first side wall not shown for clarity; Figure 11 is a perspective view of the container in the first embodiment, showing the first side wall (shown upstanding) and the third side wall, collapsed in the horizontal storage position in which it is resting on the base;

Figure 12 is a plan view of the base of the container in the first embodiment (side walls not shown for clarity);

Figure 13 is a side view of the container in the first embodiment, on the side of the first side wall or the second side when said side walls are extending upwardly from the base in an in-use position;

Figure 14 is a side view in section of the container shown in Figure 13;

Figure 15 is a side view of two containers in accordance with first embodiment of the invention, with the side walls in the in-use position, the containers shown stacked one on top of the other;

Figure 16 is an exploded view of the region A of Figure 15 showing the interlocking arrangement of the containers when in-use and when stacked on top of another container;

Figure 17 is a side view of the container in the first embodiment, on the side of the third side wall or the fourth side wall when said side walls are extending upwardly from the base in the in-use position;

Figure 18 is a side view in partial section of the container in the first embodiment shown in Figure 17;

Figure 19 is an exploded sectional plan view of the base of the container in the first embodiment;

Figure 20 is a side view of the profile of the side wall construction of the container in the first embodiment; Figure 21 is a side view of another profile of the container in the first embodiment;

Figure 22 is a perspective view of a second embodiment of the container in accordance with the invention shown in the in-use mode with the side walls upstanding from the base and with the lid positioned on the side walls.

Figure 23 is a perspective view of the container of Figure 22 but with the lid detached;

Figure 24 is an enlarged rear view of area B of Figure 22 showing the first side wall engaged with the fourth side wall;

Figure 25 is a perspective view of the second embodiment of the container in accordance with the invention shown in a collapsed mode with the side walls of the container arranged horizontally on top of each other in a storage position and the lid is secured over the collapsed side walls;

Figure 26 is a perspective bottom view of five containers of the second embodiment being stacked one on top of the other, the lowermost container showing the detail of the construction of the base of the container;

Figure 27 is another perspective view of five containers of the second embodiment being stacked one on top of the other.

Referring initially to figures 1 to 21 of the drawings, the container in the first embodiment of the invention will now be described. The container is indicated generally by reference number 1. The container 1 comprises a generally square shaped base 2 which is supported on a pallet 3. The pallet 3 is formed fully integrated with the container 1. The container 1 also includes four side walls, namely a first side wall 4, a second side wall 5, a third side wall 6 and a fourth side wall 7. Each of these side walls 4, 5, 6, 7 is moveable between an in-use position which is employed when the container is being used to transport and store produce and a storage position which is employed when the container is empty and is itself being transported to a given location or in storage. When in the in-use position, the side walls 4,5,6,7 are extending upwardly from the base 2 and generally perpendicular thereto, as shown in Figures 1 and 2 and when the container is in storage mode, the side walls 4,5,6,7, are collapsed and lay horizontally resting on each other, parallel to the base, with the lowermost side wall namely, the third side wall 6, resting directly on the base 2, as shown in Figures 6 and 7.

The container 1 also includes a lid 30 which is fully detachable from the container 1. The lid fits over the side walls 4,5,6,7, when the side walls are upstanding and assembled in the in-use position and the lid 30 also fits over the collapsed side walls 4,5,6,7 when arranged horizontally on the base 2. Lids 30 can alternatively be stacked together. The lid 30 includes a safety stacking feature, provided by four studs 31, 32 33, 34 standing proud of the lid 30. The manner in which the studs provide a safety-stacking feature will be described below particularly in relation to Figures 15 and 16.

At two sides of the base 2, along which the first side wall 4 and the second side wall 5 are provided, the pallet 3 includes side beams 34, one side beam 34 at each of the two sides. Each side beam 34 includes a pair of support feet 33.

The base 2 includes a pair of side struts 10 extending upwardly along two sides of the base, namely along the sides of the base along which the third side wall 6 and the fourth side wall 7 are provided.

The first side wall 4 and the second side wall 5 are mounted about the base using floating hinges 11, 12 respectively (first hinge assembly). The floating hinges 11, 12 essentially consist of a slot/cam arrangement comprising a pair of substantially L-shaped slots 13, 14, respectively, provided at opposed ends of each of the side struts 10, together with respective pins 15, 16 carried on triangular shaped arms 17 connected to the first side wall and the second side wall 5, respectively, the respective pins 15, 16 being moveable in the generally L-shaped slots 13, 14 respectively to allow the first side wall 4 and the second side wall 5 to be moveable between the in-use position and the storage position.

The third side wall 6 and the fourth side wall 7 are pivotally mounted on the base 2 by means of hinge arrangements (second hinge assembly) extending along the lower edges of the third side wall 6 and fourth side wall 7. The hinge arrangement which connects the fourth side wall 7 to the base 2, and allow pivotal movement of the fourth side wall 7 relative to the base 2 is shown in Figure 18. The hinge arrangement is in a form of a series of five co-axial hinges 701, 702, 703, 704, 705 provided along the lower edge of the side wall 7. The same arrangement of hinges is provided along the lower edge of the third side wall 6 to allow pivotable movement thereof relative to the base 2.

The fourth side wall 7, along two minor faces (side faces) 70, 70' thereof, is provided with five hooks, 71, 72, 73, 74, 75; 71', 72', 73', 74', 75', respectively. The hooks 71-75 are interengageable with five pins 41, 42, 43, 44, 45 provided at corresponding locations along generally C-shaped channel members 48, provided along one end (in the transverse plane) of the first side wall 4. Likewise, the five hooks 71', 72', 73', 74', 75' provided along the minor face 70' of the fourth side wall 7 are interengageable with five pins 51, 52, 53, 54, 55 provided at corresponding locations along the generally C-shaped channel member 58 provided at one end (in the transverse plane) of the second side wall 5. Therefore, the fourth side wall 7 is interengageable at one side with the first side wall 4 and at the other side, the fourth side wall 7 is interengageable with the second wall 5.

Likewise, the third side wall 6 is interengageable, along one minor face 60 thereof, with the first side wall 4 by means of five hooks (not shown) provided along the minor face 60. These hooks are interengageable with pins 41', 42', 43', 44', 45' provided in generally C- shaped channel member 48'. At the opposed edge thereof, the third side wall 6 is interengageable with the second side wall 5 by means of five hooks 61', 62', 63', 64', 65' provided along the minor face (side face) 60' of the third side wall. These hooks 61' 62', 63', 64', 65' are interengageable with five respective pins (not shown), provided in the generally C-shaped channel member 58'.

Referring now particularly to Figures 1 to 6, the manner in which the container is changed from the in-use mode during which it is used for containing products/produce to the storage mode when it is empty, will be described.

Referring initially to Figures 1 and 2, the lid 30 is removed and the first side wall 4 is firstly moved upwardly and outwardly by means of the floating hinges 11 provided on each of the side struts 10. The upward movement releases the hooks (not shown) of the third side wall 6 and the hooks (71, 72, 73, 74, 75) of the fourth side wall 7 from the respective pins (41', 42', 43', 44', 45') and (41, 42, 43, 44, 45) at each end of the first side wall 4.

The second side wall 5 is then moved upwardly and outwardly about hinges 12 provided on each of the side struts 10, thereby disengaging hooks 71', 72', 73', 74' and 75' on the fourth side wall 7 and hooks (61; other hooks not shown) on the third side wall 6 from the pins provided on the second wall 5.

Once the hooks have been disengaged, the outward movement of the first side wall 4 and the second side wall 5, provides clearance for, initially, the third side wall 6 to be pivoted about hinges (not shown) from the upright position as shown in Figures 2 to the horizontal position in which it is resting on the base as shown in Figure 4. The fourth side wall 7 is then pivoted about hinges (701 to 710) and moved from the upright position into a horizontal position where it is resting on the already horizontally lying third side wall 6. The first side wall 4 is then moved from the upright position into the horizontal position in which it is resting on the fourth side wall 7 and finally the second side wall 5 is moved into the horizontal position in which it is resting on the first side wall 4. In this arrangement, each of the horizontally lying side walls is protected by the side struts 10. The lid 30 is then fitted over the side struts 10 thereby securing the horizontally lying side walls 4,5,6,7, sandwiched between the base 2 and the lid 30.

The steps necessary to assemble the container from the storage mode shown in Figure 7 to the in-use mode shown in Figure 1 will now be described. Firstly, the lid 30 is removed and the second side wall 5 is raised about floating hinges 12 into a generally upright position but extending outwardly from the base as shown in Figures 5. The first side wall 4 is then raised about floating hinges 11 into a generally upright position but extending outwardly from the base 2. The fourth side wall 7 and the third side wall 6 are then raised into an upright position by an operator. The second side wall 5 is pushed inwardly and downwardly so that the hooks 61', 62', 63', 64', 65' on the third side wall 6 and the hooks 71', 72', 73', 74', 75' engage in the respective pins provided along the generally C-shaped channel members 58, 58' of the second side wall 5 thereby securing the second side wall 5 to the third and fourth side walls 6, 7 respectively. Then the first side wall 4 is pushed inwardly and downwardly so that the hooks 71, 72, 73, 74, 75 on the fourth side wall 7 engage in the pins 41, 42, 43, 44, 45 provided along the generally C-shaped channel member 48 of first side wall 4 and the hooks (not shown) on the third side wall 6 engage in pins 41', 42', 43', 44', 45' provided along the end (in the transverse plane) of the first side wall 4 thereby securing the first side wall 4 to the fourth side wall 7 and to the third side wall 6. The container 1 is now ready to be loaded with products/produce as shown in Figure 2. Once the container has been filled, the lid 30 may be located in position over the open top of the container 1 thereby providing a secure environment for the products/produce to be transported/stored in the container 1. The corner generally C- shaped channel members 48, 48', 58, 58' can be accommodated in recesses (not shown) provided in the lid 30. As a safety feature, the hooks are visible to an operator and the lid cannot be fitted on unless the side walls 4, 5, 6, 7 are correctly in place.

Referring now to Figures 14, 15 and 16, the stacking arrangement for filled assembled containers will be described. A container 1 as shown in Figures 14 is stacked on top of another container 1 as shown in Figure 15. To provide additional security in this stacked arrangement, the studs 31 provided on the lid 30 rest inside the feet 33 of the pallet 3 as shown in Figures 15 and shown in more detail in Figure 16. This secure stacking arrangement negates the need for belts or straps around stacked containers.

The detailed arrangement of the hooks 71, 72, 73, 74, 75 and 71', 72', 73', 74', 75' provided on the fourth side wall 7 engaged with the pins 41, 42, 43, 44, 45 on the first side wall 4 and with the pins 51, 52, 53, 54, 55 on the second side wall 5 respectively is shown in Figure 18.

The container 1 itself must be as light as possible. This is especially important when in the storage mode, so as to reduce shipping costs. The lid 30 is made from plastic material, making it highly robust. The studs 31 provide a safety stacking feature as well as adding strength to the lid. The C-shaped channel members 48, 48', 58, 58' provided at the corners of the container 1 are made from aluminium. In a modification to the container not shown in the drawings, a dispenser is fitted to one of the walls of the container so that liquid housed in the container can be dispensed directly from the container.

Referring now to Figures 22 to 27 of the drawings, the second embodiment of the container of the invention is indicated generally by reference numeral 200. Container 200 is generally similar to the container 1. Like numerals are used to indicate like features. The differences between the container 200 and the container 1 will now be described.

The side walls 204 to 207 of the container 200 are in a form of metal framework and can be welded from, for example, aluminium profiles.

Base 202 of the container 200, as can be seen in Figure 26, comprises a three-dimensional frame construction having a series of hollows 203 and crossbars 204. The base 202 is cast from a suitable material, for example, a magnesium alloy, which allows the weight of the base 202 to be minimised whilst retaining the strength of the construction. This construction of the container 200 has the advantage that the container 200 involves less complex manufacturing processes and is therefore less expensive to produce. Also the container 200 is easily and safely operated between the storage and in-use modes.

Construction of floating hinges 211 and 212 for mounting the respective first side wall 204 and the second side wall 205 on the base 202 is similar to the construction of the floating hinges 11 and 12 of the container 1 with the difference in that the respective L-shaped slots 213 and 214 of the floating hinges 211 and 212 are formed in individual plates 2110 and 2120 respectively. Plates 2110 and 2120 are fixed to the opposed ends of the two sides of the base 202 along which the third side wall 206 and the fourth side wall 207 are provided. Pins of the floating hinges 211 and 212 comprise rotatable bushings 217 and 218 respectively, as shown in Figure 24, which extend life of the pins of the floating hinges by replacing sliding friction with a rolling friction between the pins and the slots 213 and 214. The inclusion of the bushings 217, 218 has the advantage that the bushings extend the life expectancy of the floating hinges 211 and 212. The third side wall 6 and the fourth side wall 7 are pivotally mounted on the base 202 by means of pairs of hinges 280 and 208' respectively, as shown in figures 22 to 24.

Construction of locking means for securing the side walls together when the container 200 is in the in-use mode differs from that described for the container one in that the third side wall 6 is provided with a pair of elongate bars (not shown for the third side wall 206) extending along two edges thereof. The elongate bars are fixed to the edges and have a plurality hooks formed integrally along the length of the bars. The hooks are interengageable with slots provided at corresponding locations along the first side wall 204 and the second side wall 205. Hooks 271, 272, 273, 274 provided at on edge of the third side wall 206 are shown in Figure 23. These hooks are interengageable with slots 241, 242, 243, 244 provided at the respective edge of the second side wall 205 and shown in Figure 22. As shown in figure 24, the hook 274' (and other hooks not shown in figure 24) engage in the slots such that in use, the weight of the side walls is borne by the hooks bearing down in the slot whereby, in use, the hinge assemblies (i.e. floating hinges and the series of co-axial hinges) do not have to carry the weight of the side walls. This has the advantage that the hinges are not subjected to compression stresses and can operate more efficiently an have a longer life span.

Likewise, a pair of elongate bars is provided along two edges of the fourth side wall 7 and corresponding slots are provided along the respective edges of the first side wall 204 and the second side wall 205. A portion of an elongate bar 270' provided at one edge of the fourth side wall 7 is shown in Figure 24 together with a hook 274' and a mounting aperture

275'.

A pair of channels 220 is provided at each side of the base 202 for access of a lifting device of a fork-lift truck.

When the container 200 is in a storage mode, as shown in Figure 25, the lid 230 rests on the projecting plates 212 and 211 of the container. The construction of the container 200 allows up to five containers folded into the storage to be stacked one on top of the other as shown in Figures 25 and 26.

The manner in which the container 200 is changed between the in-use mode and the storage mode is identical to that of the container 1 of the invention.

The base of the container 200 incorporates weight reducing undercuts as well as being manufactured from Magnesium Alloy. These features give the container 200 the advantage of minimized weight while retaining strength.

It will of course be understood that the invention is not limited to the specific details as herein described, which are given by way of example only and that various alternations and modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS:

1. A collapsible container comprising a four-sided base, first, second, third and fourth side walls; a first hinge assembly for coupling the first and second side walls to the base and a second hinge assembly for coupling the third and fourth side walls to the base, said first hinge assembly and second hinge assembly allowing the first and second, third and fourth walls, respectively, to be moved between an in-use mode in which the container is being used to contain produce and a storage mode in which the container is empty, wherein when the container is in the in-use mode, the side walls extend upwardly generally perpendicularly from the base, and when the container is in the storage mode, the side walls lay resting on each other, parallel to the base in a stacked arrangement, with the lowermost side wall resting on the base; wherein the container further comprises locking means for enabling at least one of the side walls to be interlocked with another side wall, to maintain the side walls in the upright position when the container is in the in-use mode so that, in use, the container is securely held together, the locking means comprising interengaging formations provided on corresponding locations of the side walls.

2. A container as claimed in Claim 1 wherein the first hinge assembly comprises a floating hinge assembly, the floating hinge assembly allowing respective pivot points of the first and second side walls to be raised upwardly in the plane perpendicular to the base and outwardly in the plane parallel to the base, prior to being folded down into the stacked position over at least one of the other stacked side walls.

3. A container as claimed in claim 1 or claim 2 wherein the first and second side walls are folded down into the stacked position on top of the third and fourth side walls, with the third side wall lying on the base.

4. A collapsible container according to claim 1 in which the second side wall is uppermost when folded down into the stacked position over the other side walls.

5. A container as claimed in any one of claims 2 to 4 wherein the first floating hinge assembly includes sliding means arranged to allow the uppermost second side wall to be firstly moved upwardly in a plane perpendicular to the base and then moved outwardly in a plane parallel to the base, prior to being folded down into the stacked position.

6. A container as claimed in any one of claims 2 to 5 wherein the floating hinge assembly includes a pair of floating hinges and comprises a sliding means moveable in a generally "L" shaped slot.

7. A container as claimed in claim 1 wherein the second hinge assembly comprises a plurality of co-axial hinges.

8. A container as claimed in Claim 1, wherein the interengaging formations comprise a plurality of lock projections provided along at least one minor face of a side wall and a corresponding plurality of lock projections engaging means provided at corresponding locations on another side wall such that when the side walls are in the upright, in-use mode, the plurality of lock projections on one side wall can interengage in the corresponding plurality of lock projection engaging means on the other side wall.

9. A container claimed in claim 8 wherein the lock projections are in the form of hooks and are provided along at least one of the minor faces of two side walls and the lock projections engaging means comprise hook engaging means.

10. A container as claimed in claim 9 wherein the hooks are provided along both of the minor side faces of two side walls and the hook receiving means are provided at corresponding locations on the two other side walls, such that two of the side walls can be interlocked with the other two side walls.

11. A container as claimed in any one of claims 8 to 10 wherein the hooks are generally J-shaped hooks.

12. A container as claimed in claim 11, wherein the generally J-shaped hooks are provided along both of the minor side faces of the third and fourth side walls and the hook receiving means are provided on corresponding locations along the first and second side walls.

13. A container as claimed in any one of claims 8 to 12 wherein the plurality of hook engaging means comprise pins provided along ends (in the transverse plane) of the side walls.

14. A container as claimed in any one of claims 8 to 13 wherein the plurality of hook engaging means comprise slots provided along the transverse ends of the side walls, the slots being adapted to receive and engage with the plurality of hooks such that the weight of the side walls is borne by the hooks bearing down in the slot such that in use, the hinge assemblies do not have to carry the weight of the side walls.

15. A container as claimed in any one of claim 11 wherein the generally J-shaped hooks open upwardly towards the top of the container when the side walls carrying the hooks are in the upright, in-use mode.

16. A container as claimed in any preceding claim wherein the container includes a detachable lid which extends across an open top of the container to seal it fully when the container is in the in-use mode.

17. A container as claimed in any one of the preceding claims including a liquid draining means provided in a side wall of the container.

18. A container as claimed in any one of the preceding claims comprising an inflatable compartment.

19. A container as claimed in any one of the preceding claims comprising elevation means for raising the container to a predetermined position to facilitate discharge of container contents.

20. A container as claimed in any one of the preceding claims wherein the base of the container includes heating and cooling elements.

21. A container as claimed in any one of the preceding claims wherein the base comprises a three dimensional frame construction having a series of hollows and crossbars.

22. A container as claimed in any one of the preceding claims wherein the base is manufactured from a Magnesium Alloy which allows the weight of the base to be minimized while retaining strength of construction.