GB2263898A - Bulk containers - Google Patents

Abstract

A bulk container (10) is substantially cuboidal in shape and has a base (12) and four side walls. At each corner of the container is an iso-block (18) which iso-blocks are utilised for attaching the container to a trailer or a crane. The base (12) is provided with two doors (32, 34) which open outwardly from the base so that the container contents can be discharged without a need to turn the container. The container is provided with a locking means (50) for securing the doors in a closed position. Preferably the locking means is operated by remote control. <IMAGE>

Description

DESCRIPTION BULK CONTAINERS The present invention relates to bulk containers.

Bulk containers are used to transport materials from one location to another. They are often transported by articulated lorry and are generally adapted for attachment to a lorry trailer by having at each corner of the underside of the base of the container a hole for receiving a locking device which is rigidly mounted to the trailer when the locking device is received in the hole; part of the locking device can be pivoted through 900 by a manually operated lever so as to lock the container to the trailer.

The base of the container is usually formed of a resilient, load-bearing material, such as steel, since it is required to support a large weight of cargo.

Unlike the base of the container however, the roof of the container is usually not formed of load-bearing material, since its main function is to protect the contents of the container from climatic conditions and therefore it is not adapted to support any great weight. The roof may therefore simply consist of a thin sheet of metal. Alternatively it may consist of canvas or other weather-resistant material which can be removed so as to provide access to the container from above. This is advantageous for when it is desired to use cranes to remove the material from within the container, for example, at ports when it is desired to transfer material from the container to the cargo hold of a ship.

In a further alternative, the roof may consist of several sheets of metal which are pivotally interconnected and which are slidably mounted to the upper edges of the sides of the container. By the use of a winding mechanism, the sheets can be moved towards one end of the container in a concertina-like manner thus again providing access to the inside of the container from above.

Most bulk containers also include a door or a pair of doors at its rear end through which material can be loaded or unloaded. If the material is sufficiently light-weight and easy to handle, this is often done by hand. However for more heavy material fork-lift trucks can be used. In the case of certain non-fragile goods such as coal, material can be unloaded simply by being tipped out of the rear of the container, since many lorry trailers for transporting such containers are supplied with hydraulic lifting gear for this purpose.

When it is desired to unload containers at a port, fork-lifts can be used to remove material stacked upon pallets. However this procedure is timeconsuming and once the pallets have been removed it is still necessary to transfer the pallets from the quayside to the cargo hold of a ship. It is therefore often preferred to use a crane to place the whole container (including its contents) into the cargo hold of a ship. The container can then be shipped to its port of destination, unloaded and eventually returned to its owner. Bulk containers are however valuable and there is a growing black-market in their trade.

Hence many bulk containers tend to go missing in transit and their owners often prefer them not to be loaded onto ships since control of their whereabouts can be lost.

Recently a new method of unloading the cargo of containers at ports has been developed whereby the roof of the container is opened (e.g. by removing a canvas sheet), the container is lifted by a crane and trans located so that it is held over the cargo hold of a ship and then the container is pivoted through 1800 to turn it upside down so as to discharge its cargo directly into the cargo hold (at this point, the container is held the opposite way up to the orientation in which it is normally transported upon lorry trailers). This process is then reversed to return the trailer to the quayside.

Although in principle this operation is fairly simple, in practice it requires complex and expensive machinery to pivot the container, to support it when it is being pivoted, to hold it in position whilst its cargo is discharged and to return it to the quayside after the cargo has been discharged. Furthermore, if this operation is not performed properly it can be hazardous. Methods and apparatuses for performing this operation are disclosed, for example, in W085/00347 and at page 21 of Port Development International (September 1986) in an article which discusses the RO CON II containerised dry bulk handling system ("RO CON II" is a Trade Mark).

A similar method and apparatus is also discussed by P. Little in a Liverpool Polytechnic M. Eng.

Engineering Project Report entitled "Design of a containerised dry bulk handling system" and dated September 1989.

The aforementioned disadvantages are overcome or at least alleviated by the present invention.

According to the present invention there is provided a container for transporting bulk material; comprising side walls, a base comprising a door which is pivotable outwardly from a closed position in which the door closes off the base to an open position in which the door is open, and locking means for securing the door in the closed position.

When the container is being used to transport bulk material, the base is locked in the closed position to prevent bulk material from falling through the base. The locking means and the base should therefore be sufficiently strong to support the bulk material in the container.

However, when it is desired to unload the bulk material from the container, this can be simply and efficiently achieved by supporting the container above a place where it is desired to deposit the bulk material so that there is room for the door to open, and then releasing the locking means so that the door is opened and bulk material is deposited in the desired place.

Lifting means, such as a crane, may be used to support the container and attachment points e.g.

hooks, hoops or holes may be provided on the container for attaching the container to the lifting means. The attachment points may be provided at or close to the upper edges of the side walls e.g. at corners of the side walls (if present). Desirably, the containers are substantially cuboidal for ease of stocking, having four side-walls, a base and if desired a roof.

The side walls are desirably formed of substantially rigid, resilient material but it is not necessary for the roof (if present) to be formed of such material unless it is provided with attachment points for attaching the lifting means.

Desirably, when the container is suspended above the ground with the base substantially parallel to the ground and the side walls projecting upwards from the base, the door opens outwardly relative to the interior of the container under its own weight, once the locking means has been released.

The locking means may comprise a male member which lockingly engages a female member so as to secure the base in position. The male member may be provided on the door and the female member on a side wall (e.g. at or adjacent a lower edge thereof) or vice versa. The male member may comprise a slidably mounted bolt and the female member may comprise a hole or bracket for receiving the bolt. When the lifting means is used to lift the container above the ground, the locking means may not be readily accessible to an operator. Furthermore it may be hazardous to unlock the door manually. It is therefore preferred that the locking means is remotely operated, e.g., it may be radio-controlled.

When the contents of the bulk container have been substantially discharged therefrom it is desirable that the container can be lowered onto the ground so that the lowering of the container causes the door to close. Once the container is on the ground, the door can then be locked in position. The door may be locked manually, e.g., by the sliding of a bolt since the container may then be accessible. Furthermore since the door is closed and the container is on the floor there is no risk of an operator being injured by the door suddenly opening and/or by bulk material falling from the container. If desired however, means may be provided for locking the door remotely.

Preferably the container is adapted so that, when the door opens to release bulk material from the container, it pivots through less than 900 e.g.

through between 450 and 800. Hence, when the container is supported above the ground with the base horizontal, the door is preferably at an angle of greater than 0 e.g. of between 100 and 450 to the vertical. This can be achieved by the door being hinged so that it can only be pivoted through a limited angle. Alternatively a stopper, e.g., an elongate girder may be provided below the door which abuts the door when it has been pivoted through a certain angle to prevent the door pivoting further in the same direction. Wheels or castors may be attached to the underside of the door and are preferably positioned at or close to an edge of the door which is furthermost from the edge by which the door is pivoted.

Thus, when the container is lowered with the door open with the wheels being the lowermost components of the container, the wheels will contact a horizontal ground surface first and, as the container is lowered further, the wheels roll long the ground causing the door to pivot in the opposite direction to that which caused it to open. Eventually, as the container is completely lowered onto the ground, the wheels can cause the door to close and it can then be locked in that position with the locking means as aforesaid.

In order for the wheels to function properly, they should be the lowermost part of the container as it is being lowered onto the ground. Since the wheels will preferably be mounted substantially perpendicularly to the lower surface of the door, it is desired that the door is adapted to be pivoted through a limited angle as aforesaid. This is because, if the door were allowed to pivot freely when it is opened, it could pivot under its own weight so as to lie in a substantially vertical position so that, when the container is lowered, an edge of the door contacts the floor and the weight of the rest of the container causes the door and/or hinges by which the door may be pivoted, to buckle.

The base of the container may include a plurality of doors which operate as described above. The door or doors may constitute the whole or substantially all of the base.

In a preferred embodiment of the present invention, the base comprises two doors pivoted at opposite sides of the container. Each of the doors may have separate locking means or, if desired, the doors may overlap when closed so that locking means on one door may be used to lock both doors in the closed positions. Desirably, there is are least two locking means, one at one end of the base of the container and the other at the opposite end. If the doors have separate locking means then preferably there is a total of four locking means, each door having a locking means at each of two opposite ends of that door. Preferably the doors are rectangular or square so that the locking means are located at or adjacent edges of the door which are adjacent to edges at which the doors are pivoted.It wheels are present they are preferably located at or adjacent to edges of the doors which oppose the edges by which the doors are pivoted. If the base of the container comprises two relatively long opposing edges and two relatively short opposing edges, desirably the doors are pivoted at the relatively long opposing edges. Inner walls of the container preferably slope downwardly towards the base to channel bulk material towards the doors so that, when the doors are opened, substantially all of the bulk material can be discharged from the container. Outer walls of the container may, however, be substantially horizontal so that the container itself is cuboidal (to aid stacking).

The container is preferably adapted for attachment to lorry trailers. For example, it may include at its base a plurality of engaging means which engage with locking means protruding upwardly from the trailer so that the container can be fixed in position upon the trailer. The engaging means may for example, be iso-blocks and may be present at each corner of the base of a cuboidal container. A locking means which protrudes from the trailer is inserted into a hole at the underside of the iso-block and can then be pivoted through 900 so as to fix the iso-block in position relative to the trailer. A lever may be provided which is operatively connected to the locking means, so that an operator can lift and twist the lever to lock the iso-block to the trailer.This operation can be repeated for all of the iso-blocks at the base of the container to ensure that the container is fully secured to the trailer. By reversing this operation the iso-blocks can be unlocked. Iso-blocks may also be provided at upper corners of the cuboidal container and, since they comprise a plurality of holes, they can provide attachment means whereby a lifting device, such as a crane, can be attached to a container.

Containers of the present invention include general cargo and non-pressurised bulk containers, thermal containers and tank containers for liquids, gases and pressurised dry bulk cargo.

Cuboidal containers of the present invention preferably have dimensions within the following ranges: Length:- From 1 to 15 metres Width:- From 0.5 to 5 metres Height:- From 0.5 to 5 metres Preferred containers are ISO containers and, more preferably, are ISO series 1 freight containers. The parameters of various ISO series 1 Freight containers are available from Lloyd's Register of Shipping and are set out in the Table below.

External dimensions, permissible tolerances and ratings of ISO Series 1 Freight Containers Dimensions and tolerances based upon an ambient temperature of 20 C (68 F)

Length (L) Width (W) Height (H) K1 max. K2 max. Rating (R) Container designation Tolerance Tolerance Tolerance mm mm mm mm mm kg mm mm mm 0 0 0 1AA 12192 2438 2591 19 10 30480 -10 -5 -5 0 0 0 1A 12192 2438 2438 19 10 304808 -10 -5 -5 0 0 1AX 12192 2438 < 2438 18 10 30480 -10 -5 0 0 0 1BB 9125 2438 2591 16 10 25400 -10 -5 -5 0 0 0 1B 9125 2438 2438 16 10 25400 -10 -5 -5 0 0 1BX 9125 2438 < 2438 16 10 25400 -10 -5 0 0 0 1CC 6058 2438 2591 13 10 20320 -6 -5 -5 0 0 0 1C 6058 2438 2438 13 10 20320 -6 -5 -5 0 0 1CX 6058 2438 < 2438 13 10 20320 -6 -5 0 0 0 1D 2991 2438 2438 10 10 10160 -5 -5 -5 0 0 1DX 2991 2438 < 2438 10 10 10160 -5 -5 Within the scope of the present invention is a method of transporting bulk material from a first location to a second location and depositing the bulk material at the second location, in which a container according to the present invention is loaded with the bulk material at the first location, and the container containing the bulk material is transported to the second location, and in which the container is supported above an area where the bulk material is to be deposited and the door or doors in the base of the container are opened so that the bulk material is deposited from the container. Preferably the container is transported by lorry although for example, a train can alternatively or also be used.

Preferably a crane is used to support the container containing the bulk material as aforesaid. The bulk material may be deposited into the cargo hold of a ship.

Often bulk containers (when empty or when containing cargo) are stored by stacking one container on top of another. For stability, several such stacks may then be stacked side by side.

Stacking containers as aforesaid is advantageous in that it reduces the ground area required for storage and it can also deter theft of the container since it is necessary to unstack containers before they can be stolen. However, as thieves have become more sophisticated, lifting gear has increasingly been used to unstack containers, single containers can then be readily removed by, for example, placing them on a lorry trailer and driving them away. This problem has existed for many years and can result in significant losses for the owners of the bulk containers.

However, one embodiment of the present invention can be used to provide a surprisingly simple way of overcoming or alleviating this problem.

In this embodiment the containers in a stack are provided with locking means, whereby one container can be locked to a container which is adjacent to it (e.g.

below, above, to the left or to the right of the first mentioned container). Preferably the containers are substantially cuboidal for ease of stacking and the locking means allows one container to be rigidly secured to a container which is above or below it.

For example, each container may comprise a female and a male member. The male member lockably engages with the female member of an adjacent container to lock the two containers together and the female member lockably engages with the male member of a different adjacent container to also lock those two container together.

The male member may comprise a slidably mounted bolt and the female member may comprise a hole or a bracket for receiving the bolt. The locking means may be automatically operated; for example it may be radio-controlled. This avoids the need for an operator to operate all of the locking means manually, which could be time-consuming and dangerous.

Usually the containers will comprise two opposing rectangular side walls, a front wall, and a rear wall which opposes the front wall, and a base. A roof may be provided, but this is not essential. The base may already comprise a hole at each corner since these are usually provided for locking the container to a lorry (e.g. as iso-blocks). At or adjacent upper corners of the container a slidably mounted bolt may be provided for engaging a hole in the base of a similar container stacked above it.

Additionally or alternatively, each container may also be locked to a container to one side or it.

As an additional or an alternative safeguard, an electronic alarm system may be operatively connected to the containers in a stack. This system may for example, be sensitive to vibration so that an audible alarm is sounded when one of the containers vibrates above a pre-set threshold. A single cable may be used to interconnect the containers.

Containers are often adapted for refrigeration of their contents and include a connection point for a power supply so that refrigeration can be effected.

In a further embodiment of the present invention an electrical cable can be used to interconnect a plurality of refrigeration containers in a stack to provide a power supply for refrigeration. The same cable may also be part of the electronic alarm system as described above.

The present invention will now be described by way of example on, with reference to the accompanying drawings wherein: - Fig. 1 is a perspective view of a container of the present invention which has a base comprising two doors, the doors being shown in the closed position, and Fig. 2 is the same view of the container shown in Fig. 1 but the doors are shown in a fully open position.

Referring now to Fig. 1, a container 10 is shown so that its base 12 is visible. Also visible are a left-hand side wall 14 and a front wall 16 which oppose a right-hand side wall (not shown) and a rear wall (not shown) respectively. The container 10 does not have a roof, i.e. its top is open and it is substantially cuboidal in shape. It is a twofold axis of symmetry, being symmetrical about a first plane indicated by A-A and also about a second plane indicated by B-B.

The container 10 is provided with an iso-block 18 at each corner thereof, giving a total of eight isoblocks 18. Four of these iso-blocks 18 are provided at the base 12 of the container 10 and these can be used to attach the container to a trailer of a lorry in a conventional manner so that the container 10 can be readily and safely transported. The other four iso-blocks 18 are provided at the top of container 10 and provide points to which hooks or grapples of a crane can be attached so that the container 10 can be lifted off the ground.

The side walls of the container 10 each comprise two parts; an upper part 20, which is perpendicular to the base 12 (when the doors are closed) and a lower part 22 which is inwardly sloping (i.e. it forms an obtuse angle to the base 12 (when the doors are closed).

Stoppers 24 and 26 are provided at the underside the container 10 and these comprise elongate girders which are triangular in cross section. These stoppers are provided so as not to protrude beyond the lower edges 28 and 30 of the container 10.

The base 12 of the container 10 comprises two doors 32 and 34 which are hinged so as to open outwardly relative to the interior of the container 10. Doors 32 and 34 abut along axis 36 and each door is provided with two wheels 38 and 40, which are provided adjacent to axis 36 and which lie perpendicular to this axis. Wheels 38 and 40 (like stopper 24 and 26) do not protrude below the level of the lower edges 28 and 30. Each door is also provided with two bolts 42 and 44 which lie parallel to axis 36 and which protrude beyond the lower edge of front wall 46 and the lower edge of rear wall 48 respectively.

Adjacent each of lower edges 38 and 30 a locking mechanism 50 is provided which comprises two pivotally mounted hooks 47 and 49, for lockingly engaging two bolts 42 and 44) at the underside of container 10.

There hooks are radio controlled so that they can be automatically pivoted to a desired position. In Fig.1, these hooks are shown lockingly engaging the bolts of doors 32 and 34.

When container 10 is in use, it is filled with bulk material and is placed on a lorry trailer so that the iso-blocks 18 engage with locking devices on the trailer to hold the container 10 safely in position.

Wheels 38 and 40 and stoppers 24 and 26 do not protrude below the level of the iso-blocks 18 and therefore do not interfere with the locking of container 10 to the trailer.

When the container has been transported on the trailer to a desired location, the locking devices locking the container to the trailer are disengaged and grapples of a crane are attached to each of the four uppermost iso-blocks 18 of the container 10. The container 10 is then lifted by the crane and is swung away from the trailer so as to lie over a location where it is desired to deposit the contents of the container 10 (e.g. the cargo hold of a ship).

When the container 10 is stably held over the desired location and at a desired height (so that the contents will not be damaged when unloaded), with the doors 32 and 34 substantially horizontal, a remote control device (not shown) is used to deactivate locking mechanism 50 so that hooks 47 and 49 disengage bolts 42 and 44. Doors 32 and 34 then swing open under their own weight as well as the weight of the contents of container 10. These doors however swing only until they hit stoppers 24 and 26, since they are then in a fully open position. The weight of doors 32 and 34 however keep these doors 32 and 34 in abutment with stoppers 24 and 26 respectively so that they are held in the fully open position.

The doors 32 and 34 are shown in this position in Fig. 2. As can be seen from this figure, the wheels 38 and 40 and the bolts 42 and 44 are positioned so as not to contact stoppers 24 or 26 when doors 32 and 34 are open, thus avoiding damaging these components.

Furthermore, when the doors 32 and 34 are fully open and the container is held in an upright position, the wheels 38 and 40 are located so as to be the lowermost parts of the container 10. Thus, when the doors are opened as described above, substantially all of the contents of the container 10 are deposited therefrom since sloping walls 22 channel the contents towards the opening created at the base of the container 10 by the opening of doors 32 and 34.

When substantially all of the contents of the container 10 have been discharged, the container 10 (via the crane by which it is supported) can be swung away from the location where the contents have been deposited and can be lowered gradually onto a level horizontal surface whilst keeping the container in a substantially upright position.

As the container 10 is lowered, the wheels 38 and 40 contact the surface first and further lowering of the container 10 causes the wheels 38 and 40 to roll so as to pivot doors 32 and 34 in an opposite manner to that in which they were pivoted to open the base 12 of the container. Thus doors 32 and 34 move as indicated by arrows C and D respectively on Fig. 2 and this movement continues as the container 10 is lowered onto the ground. Eventually the bolts 42 and 44 contact hooks 47 and 49 respectively. Hooks 47 and 49 are spring loaded so that as doors 32 and 34 close further, bolts 42 and 44 cause hooks 47 and 49 to pivot thereby allowing bolts 42 and 44 to lockingly engage with hooks 47 and 49. At this point,. the doors 32 and 34 are fully closed and the four lower iso-blocks 18 rest on the level surface. The container 10 can then be stored or loaded onto a lorry trailer for transporting, as described.

Claims (15)

1. A container for transporting bulk material comprising side walls, a base comprising a door which is pivotable outwardly from a closed position in which the door closes off the base, to an open position in which the base is open and locking means for securing the door in the closed position.

2. A container as claimed in claim 1, in which the container is provided with means for limiting the door's angle of pivot to less than 900.

3. A container as claimed in claim 2, wherein said means for limiting the door's angle of pivot is an angular stopper or hinge.

4. A container as claimed in claim 3, in which one or more wheels are mounted on said door.

5. A container as claimed in claim 4, in which the one or more wheels are positioned close to an edge of the door remote from an axis about which the door pivots.

6. A container as claimed in claim 5, in which the one or more wheels are positioned to roll in a direction along an axis lying perpendicular to the axis about which the door pivots.

7. A container as claimed in any of the preceding claims, in which the container is provided with attachment points for attaching the container to a lifting means.

8. A container as claimed in claim 7, in which the container is a substantially cuboidal container having iso-blocks about the four corners of the base, and iso-blocks at the four corners remote therefrom.

9. A container as claimed in claim 8, wherein the iso-blocks at the four corners remote from the base are attachment points.

10. A container as claimed in any of the preceding claims, wherein the door may comprise a plurality of doors.

11. A container as claimed in claim 10 comprising two doors which pivot from opposite sides of the base.

12. A container as claimed in any of the preceding claims in which the locking means is remotely operated.

13. A container as claimed in any of the preceding claims, in which the locking means comprises a male member provided on the door and a female member provided on the side wall.

14. A container for transporting bulk material substantially as hereinbefore described with reference to Figs. 1 and 2.

15. A method of locking together two containers as claimed in claim 8, the method comprising interposing a male locking member between adjacent iso-blocks of adjacent containers.