Lattice piece and crane

A lattice piece for a crane includes four corner posts and of null bars and diagonal bars connecting the same, wherein at least a part of the null and diagonal bars are foldably articulated to at least one corner post, and at least one adjusting unit is provided for performing the folding movement, wherein at least one drive is connected or connectable with at least one adjusting unit.

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIRITY

This application claims the benefit of German Utility Model Application No. 20 2010 011 131.5, filed on Aug. 6, 2010, in the German Patent and Trademark Office, the disclosures of which are incorporated herein in their entirety by reference.

BACKGROUND

1. Field of the Invention

This invention relates to a lattice piece for a crane and to a crane with such lattice piece.

2. Description of the Related Art

Cranes, in particular large mobile cranes, are transported to the respective sites of use on public roads. Here, the rules of public road traffic are applicable, for example in Germany the rules of the Road Traffic Regulations. In these regulations, the maximum admissible weights and also dimensions of the crane to be transported are defined. In other countries similar regulations apply correspondingly.

These regulations lead to the fact that the dimension of the parts to be transported is limited, whereby the total size of the mobile crane and therefore the maximum achievable lifting capacity is limited.

Different approaches are already known from the present state of the art, in order to comply with the limitations during transport of the crane without reducing the achievable lifting capacity to an unnecessary extent.

It is proposed, for example, to completely demount the body of the crane, in particular the lattice boom of a lattice crane, and separately move the separated individual parts. However, the dimension of an individual lattice piece already can exceed the admissible transport size.

In DE 10 2006 060 347 A1 it is proposed to design the individual lattice piece so as to be foldable, in order to comply with the admissible transport dimensions. Such crane boom first is dismantled into its individual lattice pieces, wherein the same subsequently are folded and transported in this dismantled form.

A disadvantage of the above suggestion, however, consists in that the folding operation of the lattice piece must be effected manually. The larger the physical dimension of the lattice piece, the more force must be applied for the corresponding folding operation of the corresponding lattice piece. The potential size of manually foldable lattice pieces is limited thereby.

As proposed in DE 10 2006 060 347 A1, an auxiliary crane possibly is provided for erecting the foldable lattice piece, since the weight forces to be overcome are too high for manually erecting the lattice piece without machine force.

SUMMARY

It is an aspect of the present invention to create a lattice piece which despite its large dimension remains suitable for road transport, wherein the folding operation of the lattice piece is simplified. In particular, a corresponding auxiliary crane should remain usable for other tasks or not be required at all.

In accordance with the invention, this object is solved by a lattice piece including four corner posts and of null bars and diagonal bars connecting the same, wherein at least a part of the null and diagonal bars are foldably articulated to at least one corner post, and at least one adjusting unit is provided for performing the folding movement, characterized in that at least one drive is connected or connectable with at least one adjusting unit.

According to an aspect of the present invention, the adjusting unit includes at least one partly telescopable diagonal bar.

According to an aspect of the present invention, the telescopable diagonal bar comprises a hydraulically driveable hydraulic cylinder which is connected or connectable with the drive.

According to an aspect of the present invention, the hydraulic cylinder is maintained in position by hydraulic oil.

According to an aspect of the present invention, six null bars and four diagonal bars are articulated to each corner post.

According to an aspect of the present invention, the null bars are at least partly telescopable and driveable by said at least one drive or an additional drive.

According to an aspect of the present invention, the telescopable diagonal bars and/or null bars each are fixed in their end position via bolt connections.

According to an aspect of the present invention, the connections between the corner posts and the diagonal and null bars are at least partly flexurally rigid.

According to an aspect of the present invention, a drive is connected or connectable with a lattice piece is provided.

According to an aspect of the present invention, a crane with at least one lattice piece and the drive is provided.

DETAILED DESCRIPTION

A lattice piece for a crane consists of four corner posts and of null bars and diagonal bars connecting the same. At least a part of the null and diagonal bars are foldably articulated to at least one corner post, wherein at least one adjusting unit is provided for performing the folding movement or the folding process. This provides for a lattice piece with a much larger dimension. The admissible transport dimension is taken care of in the folded condition.

Furthermore, at least one drive is provided in accordance with an embodiment of the present invention, which is connected or connectable with at least one adjusting unit. Accordingly, the folding operation is accomplished automatically by the drive. The expenditure of force is handled by the drive, so that distinctly larger foldable lattice pieces can be realized.

According to an embodiment of the present invention, for example, a lattice piece is proposed, which in use of the crane has a length of 10 m and a height of 5 m. The width of the lattice piece approximately is designed in the order of the height, wherein the same possibly can also be designed larger or smaller. In the folded condition, a height of about 3 m is achieved, whereby the relevant rules of the Road Traffic Regulations are maintained.

A plurality of such lattice pieces then form a lattice boom, in particular a main boom, a fly jib or also a derrick boom.

While the length of the lattice pieces can be chosen such that the length can be maintained during transport, the adjusting unit or the folding mechanism preferably is chosen such that a reduction of the height of the lattice piece is effected. The folding mechanism can of course also be used for reducing the lattice piece width, possibly in combination with the reduction in height.

Accordingly, the adjusting unit preferably includes at least one partly telescopable diagonal bar. By telescoping at least one diagonal bar in and out, the lattice piece is folded from the crane operating position into the collapsed form for the transport.

Preferably, the telescopable diagonal bar includes a hydraulically driveable hydraulic cylinder. The drive according to the invention, in particular a hydraulic pump with corresponding hydraulic lines, is connected with the hydraulically driveable hydraulic cylinder or is designed to be connectable with the same. The drive is connected with the adjusting unit or with the hydraulically driveable hydraulic cylinder only on demand and effects either a retraction or an extension of the cylinder.

It is imaginable, for example, that the hydraulic cylinder is pressurized with hydraulic pressure by the drive. As drive means or hydraulic means a hydraulic oil preferably is provided. After removing the drive from the hydraulic cylinder, the same is maintained in the current position by the drive means, in particular by the hydraulic oil.

Furthermore, the lattice pieces advantageously can include corner posts which have fork-finger connections at their ends. Individual lattice pieces can be connected with each other by means of these connections to form lattice booms. To each corner post six null bars and four diagonal bars can be articulated.

In addition, at least a part of the null bars likewise can be designed telescopable, for example by using a hydraulically driveable cylinder. The adjustability of the null bars possibly can be driveable by a drive. For adjusting the null bars either the same or an additional drive can be used.

Particularly advantageously, the telescopable diagonal bars and/or the telescopable null bars each can be fixed in their end position via bolt connections, i.e. in the crane operating position or in collapsed form.

The invention furthermore relates to a drive, in particular to a powerpack, which is connected or connectable with a lattice piece according to any of the preceding embodiments. For assembly or disassembly, the drive is connected with the adjusting unit of the lattice piece. During the crane work, the drive is separated from the lattice piece. An advantage consists in that for designing a lattice boom only one single drive is required, which is connected with the lattice pieces one after the other. The drive provides the necessary energy for assembly or disassembly of the lattice pieces, i.e. for actuating the folding mechanism.

Furthermore, the invention is directed to a crane, in particular to a mobile crane or crawler crane, with at least one lattice piece according to any of the preceding embodiments. Furthermore, the crane preferably provides a drive, in particular a powerpack for assembly or disassembly, i.e. for actuating the folding mechanism, of the individual lattice pieces.

FIG. 1shows a lattice piece1according to an embodiment of the invention in a side view. This foldable lattice piece1consists of four corner posts11,13, wherein only the corner posts11,13located at the front can be seen in the drawing. Furthermore, a larger number of null bars15,16,17and diagonals18,19are provided. Thus, four side faces are obtained for the lattice piece1, of which two side faces facing each other are constructed identically.

All connections between the corner posts11,13and the null bars15,16,17or the diagonal bars18,19are hinged about swivel axes12. The swivel axes12are formed by bolts in a known manner.

The illustrated side face of the lattice piece1of the invention as shown inFIG. 1reveals the two corner posts11,13extending parallel to each other, which are connected with each other via the null bars15,16,17. Furthermore, the two diagonal bars18,19extend to the opposite corner post11proceeding from the connecting point of the middle null bar16at the corner post13. The side face of the lattice piece1located behind the same in parallel is constructed identically.

The lattice piece1, as it is shown inFIGS. 1,2, for example has a length of 10 m and a height of 5 m in the non-folded form. The width of the lattice piece1approximately lies in the order of the height.

To be able to transport this lattice piece on the road, it can be folded together due to the pivotal connection between the corner posts11,13and the corner posts of the side face located behind the same. The collapsed form is shown inFIG. 2.

The stability of the lattice piece1is achieved by the diagonally stretched-out diagonal bars18,19. The same prevent that the respective corner posts11opposite the corner posts13are folded into the collapsed position. In the illustrated embodiment, the diagonal bar18is designed to be actively variable in its length by means of the hydraulically driven cylinder unit. In the extended condition of the driven cylinder, the lattice piece1is erected and ready for the crane operation.

For folding together, the diagonal bar18, i.e. the hydraulically driveable cylinder, is retracted. The retracting movement of the hydraulic cylinder effects a swivel movement of the upper side wall of the lattice piece1with the corner posts11to the left, wherein the null bars15,16,17swivel about their bearing points12at the corresponding corner posts11,13. The second illustrated diagonal bar19is telescoped out (i.e. extended) as a result of the swivel movement. For stabilizing the lattice piece1in the collapsed form, the telescopable diagonal bars18,19are bolted in their corresponding end position.

Other than in the illustrated embodiment, it would be possible to likewise design the second diagonal bar19in the active form and as a hydraulically driveable cylinder. This would ensure synchronism of both sides or of the diagonal bars18,19.

To perform the swivel movement, an externally arranged powerpack is provided, which on demand can be connected with the active diagonal bar18of the lattice piece1. By means of the powerpack, the hydraulically driveable cylinder of the diagonal bar18is pressurized with a corresponding hydraulic pressure which effects the corresponding folding movement of the lattice piece1. After the assembly or disassembly of the lattice piece, the powerpack is separated from the lattice piece1. In particular, this offers the advantage that only one single powerpack is required for mounting or demounting individual lattice pieces of a mobile crane one after the other.

Due to the folding mechanism explained, the lattice piece1according to the invention can reduce its height from 5 m to 3 m during operation of the crane. Since always only two directly adjacent corner posts11,13are connected with each other, not only the height, but also the width of the lattice piece1could be reduced according to the same principle.

The lattice boom of a crane is composed of a plurality of the presented lattice pieces1. The individual lattice pieces1are connected with each other via the fork-finger connections20.