The invention relates to a device for unloading general cargo from a shipping container or truck.

Many goods are transported in shipping containers or in trucks. In order to make optimal use of the available space in for instance a shipping container the goods, usually boxes, are stacked directly on the bottom of the shipping container. With a view to making maximum use of the space, use is not made here of pallets.

Such a method of storing general cargo is particularly known for general cargo which has to be transported over large distances, such as goods being transported from China to Europe or the United States.

At their destination, these shipping containers have to be unloaded again. These shipping containers must then be unloaded by hand because the general cargo is placed not on pallets but on the bottom of the container. The general cargo is then picked up one by one by hand, and subsequently placed on an accordion roller conveyor for further processing. As the unloading of a container progresses and the general cargo is picked up further into the container, the accordion roller conveyor will be extended into the container.

In addition, it is known to load such shipping containers according to the so-called snake loading principle. The diverse numbers of goods are here placed in the container in order, so that they exit the container in the correct order when the container is unloaded.

When such a snake-loaded shipping container is unloaded in the conventional manner, the goods will be placed on the accordion roller conveyor one by one and will have to be placed in grouped manner on for instance a pallet again at a different location. The goods must here be picked up by hand at least twice, which is labour-intensive and is not very ergonomic.

It is now an object of the invention to reduce or even obviate the above stated drawbacks.

This object is achieved according to the invention with a device, which comprises:

- a mobile driven chassis;

- a height-adjustable platform arranged on the chassis;

- at least one individually height-adjustable primary roller track arranged on the chassis adjacently of the platform;

- at least one secondary roller track which is arranged on the chassis at a fixed height and lies adjacently of at least one primary roller track on the opposite side relative to the platform; wherein the at least one primary roller track is at least adjustable between a first position and a second position, wherein in the first position the transport surface of the primary roller track lies higher than the transport surface of the adjacent secondary roller track, and in the second position the transport surface of the primary roller track lies flush with the transport surface of the adjacent secondary roller track.

Because the device is mobile by means of the mobile driven chassis, the device can be placed in front of a shipping container for unloading in simple manner and, if necessary, also be moved into the container.

A person who will be unloading the container can then adjust the platform in the height, so that boxes can be taken up from a stack in the container at an ergonomic height. Because at least one primary roller track is further likewise height-adjustable, the person can also place the picked-up box on the primary roller track again at an ergonomic height.

Since the primary roller track is height-adjustable independently of the platform, a stack of the boxes can be formed on the primary roller track, preferably on a pallet, wherein the height of the primary roller track is controlled such that the upper side of the formed stack is always at a fixed height.

When the formed stack is sufficiently high, or when a different type of goods exit the snake-loaded container, the stack can be discharged via the secondary roller track and a new stack of a different type of general cargo can be formed on the primary roller track.

The advantage of the device according to the invention is that the goods from the container need be picked up only once and then come to lie on a stack on a pallet, after which the stack can be transported further by means of a forklift truck.

In a preferred embodiment of the device according to the invention the platform is displaceable between a third position and a fourth position, wherein in the third position the upper surface of the platform lies higher than the transport surface of the secondary roller track and in the fourth position it lies flush with or lower than the transport surface of the secondary roller track.

Because the platform can be brought to a position flush with or lower than the transport surface of the secondary roller track, it is possible to position the platform as low as possible in the container so that the items of general cargo which are placed on the bottom of the container can also be removed and placed on the primary roller track in simple manner.

In a further preferred embodiment of the device, the device further comprises two primary roller tracks which are at least adjustable between the first position and the second position, and wherein the device comprises two secondary roller tracks which are arranged on the chassis at a fixed height and which each lie adjacently of a respective primary roller track on the opposite side relative to the platform.

In snake loading two different types of general cargo are often placed alternately in the container since optimal use can thus be made of the limited space in the container. By providing two primary roller tracks two stacks of two different types of general cargo can be formed simultaneously and, if necessary, be discharged via the corresponding secondary roller track.

With this embodiment it is also possible to supply empty pallets to the primary roller tracks via one of the secondary roller tracks, and to discharge the pallets with stacked general cargo via the other of the secondary roller tracks.

Yet another preferred embodiment of the device further comprises two parallel tertiary conveyors for supplying pallets in upright manner, which tertiary conveyors are arranged between the two primary roller tracks and two secondary roller tracks, wherein the tertiary conveyors reach to the platform.

The secondary roller tracks can thus provide for discharge of the filled pallets and a pallet can simultaneously be tilted from the tertiary conveyor onto the primary roller track. A higher efficiency is hereby achieved, and the waiting time for the unloading person is limited in that a new, empty pallet can already be placed on the primary roller track while a filled pallet is still being discharged over the secondary roller track. In another embodiment of the device according to the invention a tiltable flap is arranged on the platform on the side remote from the at least one primary roller track.

The flap provides for a gradual transition between the platform and the bottom of the container or another ground surface when the platform is arranged in the lowest position. This is because the platform should not be lowered all the way onto the ground surface, this in order to prevent the danger of, particularly, feet getting trapped.

Yet another preferred embodiment of the device according to the invention comprises a control and a height sensor coupled to the control for the purpose of measuring the height of objects, such as stacked boxes, placed on the at least one primary roller track, wherein the control adjusts the height of the at least one primary roller track on the basis of the height measured by the sensor and the position of the platform.

With the sensor the height of the primary roller track can be adjusted automatically to the height of the stack of objects so that a subsequent item of bulk cargo can always be placed at the most ergonomic height, without the unloading person having to manually adjust the primary roller track in the height.

These and other features of the invention are further elucidated with reference to the accompanying drawings.

Figure 1 shows schematically a perspective view of an embodiment of the device according to the invention.

Figures 2A-2C show the device according to figure 1 in side view in three different positions.

Figure 3 shows a schematic top view of a second embodiment of the device according to the invention. Figure 1 shows a device 1 according to the invention. Device 1 has a mobile chassis 2 on which a height- adjustable platform 3 is arranged. Arranged adjacently of platform 3 are two height-adjustable primary roller tracks 4, 5, each with a pallet 6, 7 thereon.

On chassis 2 two secondary roller tracks 8, 9, arranged at a fixed height, are provided parallel to each other. Further arranged between these two secondary roller tracks 8, 9 is a tertiary conveyor 10 whereby upright, empty pallets 11 can be supplied to the primary roller tracks 4, 5.

Device 1 is mobile and can thereby be positioned in front of a stack of general cargo, for instance boxes 12.

Device 1 is shown schematically in side view in figure 2A. The primary roller track 4 with an empty pallet 6 thereon is height-adjustable by a scissor construction 13. The pallets 14 stacked full of boxes 12 can be discharged over the secondary roller track 8.

In figure 2B a person P is positioned on platform 3 and takes up boxes 12 from the stack of general cargo, as shown in figure 1, and places them on the stack of boxes 12 on the pallet 6 on primary roller track 4. The height of primary roller track 4 is chosen such that the person P is able to pick up the box 12 and put it down again in a horizontal movement.

In figure 2C the stack of boxes 12 on pallet 6 is higher, whereby the primary roller track 4 has taken up a lower position, while platform 3 is conversely positioned higher in order to once again enable the person P to place the picked-up boxes 12 on the stack on pallet 6 in a horizontal movement.

Figure 3 shows a schematic top view of a second embodiment 20 of a device according to the invention. Just as the device 1 according to figures 1 and 2, device 20 has a height-adjustable platform 21 for one or more people. Provided adjacently of platform 21 are primary roller tracks 22, 23 which are individually height-adjustable, and arranged therebehind at a fixed height are two secondary roller tracks 24, 25.

In device 20 empty pallets 26 are supplied over secondary roller track 24 and placed on the two primary roller tracks 22, 23. Goods, such as boxes 27, 28, are there stacked on the pallets. Because two pallets can each be positioned individually on a primary roller track 22, 23 adjacently of platform 21, it is possible to stack two separate kinds of general cargo 27, 28, which are placed in snake-loaded manner in a container, separately.

When pallets 26 have been fully stacked or when a different kind of general cargo must be stacked, the pallets with the boxes 27, 28 thereon can be discharged via the secondary roller track 25.