DE3015600A1 - Telescopic jib for mobile crane - has sections aligned by guide during extension and secured by locking lever before bolting together - Google Patents

Abstract

The telescopic sections for the jib of a travelling crane are aligned by a guide system after they have been extended by a hydraulic cylinder (2) so that they can be locked together. The inner section (1') has a roller carried by brackets projecting from it, travelling in a guide (3) which is shaped to align its lower surface (5') with that (5) of the outer section (5). At the same time, a locking arm (8) secured by a hinge (9) to the inner section is connected at its other end to the outer section. The guide holds the sections in tension and then the flanged ends of the two sections can be bolted together.

Description

Method for extending telescopic parts of a crane boom The invention relates to a method for extending telescopic parts of a boom of cranes, in particular cranes mounted on vehicles, and a crane boom.

When the telescopic parts of a crane boom are extended, they overlap For reasons of leadership and stability, the telescope parts in sections, i.e. the Telescopic parts are not extended to their full length from the next outer telescopic part. This has the disadvantage that the dead weight of the crane boom is not around it extended sections of the telescopic parts increased without increasing the load capacity. will.

In addition, the cost of materials for the telescopic parts is accordingly higher. The bending moment from the crane load and the weight of the extended parts is with conventional Tcleskop booms by a force of one Telescope part transferred to the other, which results in high lateral forces and thus great stress has the consequence.

The present invention is now based on the object of a method and to create a telescopic crane boom that enables the dead weight of the crane jib with at least the same load capacity to reduce the same or a higher load capacity with the same material use of the crane boom.

In order to achieve this object, a method and a Crane boom proposed with the features characterized in the claims.

The essence of the invention can be seen in a possibility for that Having found extended telescopic parts to be joined together without overlapping. This has the advantage of saving weight by eliminating interlocking ones End sections of not fully extended telescopic parts and thus the reduction the dead weight of the crane boom. The one arranged in the top chord on train stressed connecting rod and the juxtaposed to the aligned system and interconnected lower chords ensure perfect power transmission, which is superior to the conventional crane boom because of the transition the Forces from one telescopic part to the other, no transverse forces occur. The inventive The solution corresponds to a coupled one in the area of the transition between the telescopic parts Bending beam.

There are various solutions for the purely structural design, one of which is shown by way of example in the drawing to which the invention but not intended to be limited.

Fig. Shows schematically the process of extending a telescopic part from another in the last phase, FIG. 2, the non-overlapping extension end position and FIG. 3 shows the telescopic parts which are frictionally connected to one another after they have been put together and bolt.

The figures show excerpts from two telescopic parts 1, 1 'from which the telescopic part 1 'by means of a hydraulic piston 2 from the larger telescopic part 1 is extendable. The Tcleskopteile 1, 1 'can have any configuration Act Kaslenprofile three-, four- or polygonal cross-section or l'aclwerkträger.

In the final phase of the extension shown in FIG. 1, the telescopic part 1 'in the telescopic part 1 in a link guide 3 initially along an inclined section 4 guided in such a way that it is in the extended end position shown in FIG his lower chord 5 'is aligned with the lower chord 5 of the telescopic part 1, which in this Position existing certain about was the extended telescopic part 1 'opposite the telescopic part 1 can after switching a switch in the link guide 3 through Moving back along a guide section 6 parallel to the direction of extension is closed so that the lower chords 5, 5 'come to rest against one another. On the lower chords 5, 5 'can be formed flange-like contact surfaces 7 that the bolting of the Telescopic parts 1, 1 'on the lower chord 5, 5' facilitate.

There is a connecting rod on the upper belt of the extended telescopic part 1 ' 8 hinged at 9, which is initially within the envelope surface during the extension process of the telescopic part 1 '(Fig. 1). Towards the end of the extension process of the telescopic part 1 ', the rod 8 is unfolded outwards (FIG. 2) and before the end position of the system is reached of the telescopic parts 1, 1 '(Fig. 3) are bolted to the top flange 10 at 11.

The rod connecting the upper chords 10, 10 'of the telescopic parts 1, 1' 8 transmits the tensile forces and the compressive forces acting in the lower chord 5, 5 ' over the contact surfaces 7 transfer. In the event of The bolting of the lower chords can cause tensile forces from side loads on the boom 5, 5 'record this.

This design of the crane boom also results in a special one torsion-resistant connection of the telescopic parts 1, 1 '.

The procedure is carried out when the telescopic parts are retracted in reverse order to that described above for the extension, namely starting from the bolted end position according to FIG. 3 via the extended end position in FIG. 2 into the position according to FIG. 1.

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Claims (5)

Claims: 1. A method for extending telescopic parts of a boom of cranes, in particular cranes mounted on vehicles, d u r c h e k e n n z e i h n e t that the telescope parts when extending from the base or another telescopic part in its end section until it is reached an overlap-free end position so that in this position the belts of all telescopic parts that are primarily subject to pressure are aligned with one another, and then the upper chords and the lower chords are connected to one another. 2. The method according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the connection of the lower and upper chords is made by bolts. 3. Crane booms, especially for mobile cranes, with from the basic shot retractable and extendable telescopic parts that every Teieskopteil (1, 1 ') in the last exit section in a slotted guide (3) designed in this way in the adjacent one on the outside Telescopic part (1 ') is guided that in the extended state without overlapping the belts (5) of the telescopic parts (1, 1 '), which are mainly subjected to pressure, with one another come flush with the system and, if necessary, bolted and the upper chords (10) are connected to rods (8). 4. crane boom according to claim 3, d a d u r c h g e k e n n -z e i c h n e t that the rod (8) at the rear end of the extended telescopic part (1 ') is articulated and in the extended state of the telescopic part without overlapping (1 ') can be connected to the adjacent (1) on the outside, e.g. by bolts. 5. crane boom according to claim 3, d a d u r c h g e k e n n -z e i c h n e t that the link guide (3) is equipped with a switch, the one to the extension direction inclined and has a parallel guide section (4; 6) such that the telescopic part (1 ') in the overlap-free extended extended position along of the inclined section (4) and when resetting up to the contact of the telescopic parts (1, 1 ') -guide one another along the parallel section (6)