The technical problem consists basically in the conflict between two systems.

World-wide highway codes set limits on the maximum width and other dimensions of a vehicle. On the other hand, the dimensions and the maximum weight of a transport container are specified under international standards. Thus, the technical problem is how to adapt a high-capacity container crane to the dimensions of a vehicle without the retracted crane impeding the access to the transport container.

The permissible maximum width of a vehicle sets limits on the boom lengths. The problem of the task is accentuated by the fact that an adequate structural length must be provided for the cylinders. In addition, it is desirable to use the commercially available model of a trailer with minimum modifications, i. e. special solutions in trailers are preferably avoided.

Current container handling equipment usually comprises two conventional boom cranes at the end of the container. For this reason, it is difficult to use the vehicle for any other task than for transferring a container. Thus, for instance, the rearward crane blocks the way for loading and unloading. Consequently, the container cannot be unloaded or loaded when placed on the vehicle, but only when placed on the ground. Also, due to the construction of the set of booms and their trajectories, current container handling equipment cannot be mounted in (laterally opening) closed housings. The unloaded weight of current pieces of equipment has also been stated to be relatively high. This results in reduced carrying capacity of the vehicle, i. e. in a reduced cargo size and volume.

A container handling device of this type, known per se, has been described in US patent specification 4,019,642.

The purpose of this invention is to overcome the drawbacks described above. The apparatus in accordance with the invention is characterised by the fact that at least

one of the cranes is placed on the chassis of the vehicle, embedded in the cargo platform, so that, with the sets of booms retracted, i. e. in rest position, their upper faces are located in the same plane as the deck plane of the cargo platform.

With the solution in accordance with the invention, the apparatus will not increase the dimensions of the vehicle to be handled in any direction, and thus it will not reduce the cargo space nor the potential of the vehicle in any way. We may note that this is the only container handling apparatus which can be driven into a position, i. e. rest position, where it does not reduce the cargo space at all. This allows continuous use of the apparatus also in cargo vehicles, and does not require removal of the container handling units.

Various embodiments of the invention are described in the dependent claims of the set of claims, in which figure 1 shows the container handling apparatus of one embodiment mounted in a vehicle, such as a lorry, figure 2 shows the same as figure 1, but viewed from behind, figure 3 shows the same as figures 1 and 2, but viewed from above, figure 4 shows a container handling apparatus of another embodiment mounted in a trailer and viewed from behind, figure 5 and 6 are axionometric views of a pair of cranes of antoher embodiment, and figure 7 shows the pair of cranes of figures 5 and 6 mounted in a trailer, figue 8 shows the forward crane viewed from another angle.

The apparatus comprises a pair of cranes 3,4 provided with sets of booms. The set of booms comprises a base boom 6, a main boom 8 and a folding boom 10. The pair of cranes may also be referred to as handling units. A handling unit comprises cylinders 12,13, the main boom cylinder having been denoted with 12 and the folding boom cylinder with 13. The apparatus also comprises support legs 20,21. In the embodiment illustrated in figure 1, the pair of cranes is located in the same plane as the cargo platform 2. The forward set of booms 4 may be placed on the cargo platform, as illustrated with dashed lines.

Figures 4 to 8 relate to a second embodiment, where the forward handling unit is placed on the cargo platform 2 and the rearward handling unit is located in the plane of the cargo platform. The handling unit located in the plane of the cargo platform 2

has been placed on the chassis 7 of the vehicle 1, the set of booms being in retracted position, i. e. rest position, within the base boom, and then the upper sides of the entire set of booms are located in the same plane as the deck plane of the cargo platform 2. The base booms 6 of the pair of cranes are located in a transversely horizontal position on the vehicle chassis or the cargo platform. The main boom 8 and the folding boom 10 are located adjacent each other within the base crane, the upper sides of the main boom and the folding boom forming a plane base without increasing the dimensions of the vehicle to be handled in any direction, without reducing the cargo space and without limiting the potential of the vehicle in any way. Both the cylinders 12,13 have been pivoted in the base boom 6 such that, in rest position, they are partly in sequence and partly overlapping or in parallel. The main boom 8 and the folding boom 10 comprise profiles encapsulated in cross- section, the cylinders 12,13 settling into a protected position underneath these with the set of booms in rest position. One end of the folding boom cylinder 13 is pivoted 15 into the base boom 6. Owing to the four-point pivoting 11,16 and 15,14 of the cylinders 12,13, and to the main boom 8 located between these, horizontal transfer can be performed in the handling unit. The folding boom 10 and the main boom 8 are interlinked by means of the shaft 22 so as to be located adjacent each other. The pivoting point 9 of the main boom in the base boom is located above the pivoting point 14 of the main boom cylinder 12, so that sufficient initial force is provided to hoist the set of booms from rest position into operating position. The forward support leg consists of a rod which is pivoted in the base boom 6 and can be lifted into rest position, figure 7, and lowered into operating position by means of a compression cylinder 23. The rearward support leg 20 comprises a telescope housing placed underneath the set of booms and having a vertical position adjustable by means of the compression cylinder 24, which is pivoted on the same axis 9 in the base boom as the main boom 8. Thus a maximum length is obtained for the cylinder 24, and the forces of the main boom are transmitted directly to the support leg, allowing a lighter construction.

Figure 8 shows how the one end of the cylinder 23 of the support leg 21 is linked into the lug 26 of the base boom 6 through an opening in the main boom 8. Figures 5 and 8 also show how the folding boom 10 is linked into a special projection of the main boom so as to provide an additional height of up to 40 cm.

The design of the apparatus also allows for quick-fastening installation.

The container fasteners can be fastened to the base boom 6 of the handling unit, and then no separate container fastener beam (connecting the container fasteners) will be required.

The handling unit being fastened by sliding fasteners, containers of any lengths can be handled, because the container fasteners will always be at the right point.

The cylinder 13 is a telescopic, preferably three-phase cylinder. The first phase is adapted to open the folding boom 10 into lifting position. The second phase carries out the actual lifting operation. The third phase will be required only when additional lifting height and extension are desired. The loading and unloading of the container require only two phases. The long lever arm of the folding boom allows a lightweight folding boom despite the safety coefficient required under hoisting apparatus standards. The lever arm is preferably in the range of 1/2.320%. The apparatus even allows one container to be lifted on top of another. A two-phase cylinder will be sufficient if the containers to be handled are not placed on top of one another, so that a smaller lifting height is required.

The cylinders 13 are mounted"inversely", i. e. the cylinder liner of the telescopic cylinder has been linked in the folding boom 10 and its arm has been linked in the base boom 6. With this arrangement, the cylinder is less exposed to damage, even if it would, by mistake or because of careless handling, hit another container at the beginning of the lifting step.

The vehicle or the trailer is usually equipped with double-circuit hydraulics. In other words, the two handling units can be used simultaneously or separately. The control of the hydraulic valves is usually performed as remote control either via a cable or radio, however, the apparatus can also be driven directly by means of control levers on the valve kit. The movement of the booms of the handling unit is actuated by cylinders 12 and 13. The cylinders have large lever arms within the cargo handling range of the crane. When the apparatus is driven into"rest position", the lever arms of the handling unit cylinders are small, but so is the need for torque, since the apparatus is only loaded by its own weight in this position.