BACKGROUND ART There are many occasions when the owner or driver of a lorry, such as a light delivery vehicle needs or wants to increase the capacity of the bin without having to go to the expense of replacing the existing bin with a larger one.

It is an object of the present invention to provide a device which allows a simple increase in carrying capacity to be achieved at minimum cost.

DISCLOSURE OF THE INVENTION According to the invention a bin of a lorry is provided with rearwardly-extending horizontal bars which are adapted to be moved between a first position in which they are foldable or slidable into or under the chassis or the bin and a second position in which they extend rearwardly to constitute a pair of cantilevers which are able to support an extension unit.

In one form of the invention the extension unit has formations adapted to receive the cantilevers, in sliding relationship-with a possibility of locking in position.

The extension unit may comprise an additional bin which may be added to the primary bin behind the tailgate. Alternatively, the tailgate may be folded to a neutral position-in which case the secondary bin may have its one side removed so that the effective carrying capacity is increased with respect to the total length of the load-carrying bin which is thus increased by the width of the secondary bin without the side adjacent the folded-away tailgate.

The removed side may be folded away so that the extension unit can either comprise an additional secondary bin or else a direct extension of the primary bin.

The cantilevers may be hinged at either side of the primary bin for movement between a first position which may be transverse to the bin or parallel to the bin with the free ends of the cantilevers pointing towards the cab; and a second position in which the free ends are pointing rearwards and the cantilevers extend rearwardly to add length to the bin. Locking means may be provided for either or both of the positions.

The additional bin or other unit may include channels of cross-section corresponding with the cross-section of the cantilevers, which receive the cantilevers and in this manner are supported thereby.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention are described below with reference to the accompanying drawings, in which : Figure 1 is a rear view of a lorry with a pair of cantilevers in an intermediate position; Figure 2 is a similar view with the cantilevers in a folded position ; Figure 3 is a front view of an additional bin; Figure 4 is an isometric side view of the rear of a lorry with an additional bin in position; Figure 5 is a similar view showing an intermediate position of the additional bin; and Figure 6 is an isometric view of another form of additional bin.

BEST MODE FOR CARRYING OUT THE INVENTION In Figures 1 and 2 a lorry has a compartment 10 above the folded-down tailgate 11, the compartment accommodating a pair of cantilevers 12. These are hinged at 14 so that

they can be moved between a folded position in the compartment to a position in which they are parallel. Figure 1 shows an intermediate position.

Figure 3 illustrates an additional bin 16 which has parallel channels 18 to receive the cantilevers 12 when the latter are in their parallel position. The additional bin is merely pushed on the cantilevers as illustrated in Figures 4 and 5, the latter being in an intermediate position while in the former the additional bin is in its load-carrying position, in which it is preferably locked.

Rear lights 20 are provided and suitable warning means, such as a red flag should be used if the rearward length of the additional bin exceeds the legal limit.

The additional bin may take the form of a drawer with one side removed.

In Figure 6 an additional bin 30 is provided on legs 32 which are mounted on channels 34 for receiving the cantilevers.