DE3015600C2 - Crane boom with telescopic parts - Google Patents

Description

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The invention relates to a crane boom, in particular for vehicle cranes, with a basic shot and extendable telescopic parts, in which the telescopic parts when extending from the base section or a other telescopic part in its end section until it reaches an end position in which the predominantly on The belts of all telescopic parts subjected to pressure are aligned with one another and the upper and lower belts respectively are connected to one another, guided along a guide section inclined to the extension direction are.

When the telescopic parts of a crane boom are extended, they often overlap for reasons of guidance and stability the telescope parts in sections, d. H. the telescopic parts are not extended to their full length next outer telescope part extended. This has the disadvantage that the dead weight of the crane boom is increased by these non-extended sections of the telescopic parts without increasing the load capacity. Besides the cost of materials for the telescopic parts is correspondingly higher. The bending moment from crane load and the dead weight of the extended parts is determined by a couple of forces in conventional telescopic booms transferred from one telescopic part to the other, resulting in high transverse forces and thus great stress has the consequence.

A crane boom with the generic features is known from DE-OS 21 01 837. With this one known crane boom, the telescopic parts are not free of overlap in the end position, the lower chords cursed however. The extendable sections are along a rail with an inclined section in the end section possesses, guided The extended telescopic parts are connected to one another by socket pins.

The invention is now based on the object of providing a crane boom with the features of the generic type to further improve that the dead weight of the crane boom while maintaining a perfect Power transmission is reduced to a higher load capacity of the crane boom with the same material use to reach.

To solve this problem are according to the invention for a crane boom of the generic type characterizing features of claim 1 proposed. An advantageous embodiment of the invention The crane boom is characterized in claim 2

The crane boom according to the invention solves the problem Task by creating an overlap-free end position of the telescopic parts in the full through a link guide extended state is reached. This has the advantage of saving weight by eliminating them nested end sections, which reduces the dead weight of the crane boom can be. The connecting rod that is arranged in the upper chord and that is subject to tensile stress and the one that is in alignment System of juxtaposed and interconnected lower chords ensure perfect power transmission, the conventional crane boom is superior because when the forces are transferred from one on the other side of the telescope part no transverse forces occur. The solution according to the invention corresponds in the area the transition between the telescopic parts a coupled bending beam.

There are various options for purely structural design Solutions, one of which is shown by way of example in the drawing, however, relate to the invention should not be restricted.

F i g. i shows schematically the process of dying out a telescope part from another in the last phase,

Fig. 2 the overlap-free extension end position and

3 shows the telescopic parts connected to one another in a non-positive manner after they have been put together and bolted.

The figures show sections of two telescopic head parts 1, 1 ', of which the telescopic part Γ by means of a hydraulic piston 2 from the larger telescopic part 1 can be extended The telescope parts 1, Γ can be any three, four or act polygonal cross-section or truss.

In the final phase of the extension shown in Fig. 1, the telescopic part Γ in the telescopic part 1 in a Link guide 3 initially guided along an inclined section 4 in such a way that it is in the position shown in FIG. 2 shown Extended end position with its lower chord 5 'is aligned with the lower chord of the telescopic part 1. The in this position existing certain overhang of the extended telescopic part Γ compared to the telescopic part 1 can after switching a switch in the link guide 3 by moving back along one to the direction of extension parallel guide section 6 are closed so that the lower chords 5,5 'to rest against each other come. Flange-like contact surfaces 7 can be formed on the lower chords 5, 5 ', which the bolt of the telescopic parts 1.1 'on the lower chord 5.5'.

A connecting rod 8 is hinged at 9 on the upper belt of the extended telescopic part 1 '. the during

of the extension process is initially within the envelope surface of the telescopic part Γ (FIG. 1). Towards the end of the extension process of the telescopic part Γ the rod 8 is unfolded outwards (F i g. 2) and before reaching the System end position of the telescopic parts 1, 1 '(FIG. 3) bolted to the upper flange 10 at 11

The upper chords 10,10 'of the telescopic parts 1, Γ connecting Rod 8 transmits the tensile forces, and the compressive forces acting in the lower chord 5,5 'are via the Transfer surfaces 7. In the event of tensile forces from side loads on the boom can dk? Pin the lower chords 5.5 'to accommodate them.

This design of the crane boom also results in a particularly torsion-resistant connection the telescopic parts 1, f.

When the telescopic parts are retracted, the process proceeds in the reverse order to that described above for the extension, namely starting from the bolted end position according to FIG. 3 about the extended end position in FIG. 2 in the position shown in Fig. 1.

1 sheet of drawings

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Claims (2)

Patent claims: 1. Crane boom, especially for mobile cranes, with telescopic parts that can be retracted and extended from a basic section, in which the telescopic parts when extending from the basic section or another telescopic part in their end section until they reach an end position in which the belts, which are mainly subjected to pressure, are all Telescopic parts are aligned with one another and the upper chords and the lower chords are connected to one another, are guided along a guide section inclined to the direction of extension, characterized in that each telescopic part (1, V) in the last extension section in a link guide (3) in the respectively adjacent telescopic part ( f) is guided which is equipped with a switch which is inclined to the outward travel direction and has a guide section (4; 6) parallel to it, in such a way that the telescope S $ 1 ') after reaching the overlap-free extended position until the telescope parts are in contact (1,1 ') together along the parallel section (6) can be reset, the upper straps (10) being connected to rods (8). 2. Crane boom according to claim 1, characterized in that the rods \ S) are articulated at the rear end of the extended telescopic part (1 ') and in the extended state of the telescopic part (V) without overlapping with the upper chords (10) of the externally adjacent telescopic part ( 1), e.g. B. by bolts (at 11), are connectable.