DE29919790U1 - Tower crane - Google Patents

Description

04.11.1999 02611-99 G/sk

Liebherr-Werk Biberach GmbH D-88400 Biberach an der Riss

Tower crane

The invention relates to a guyed tower crane with a boom pivot piece hinged to the tower top, to which a further boom piece is hingedly connected, with a rear guy element which runs from a fixed point on a rotating platform to a fixed point on a support hinged in the area of the tower top, and with two further guy elements which run from a fixed point of the support or a fixed point of a further support hinged in the area of the tower top, which is connected to the first support by a tension element, to fixed points on the boom pivot piece and the further boom piece.

Tower cranes of this type are known in different designs.

For example, EP _n 0 132 572 B1 discloses a self-assembling tower crane with a telescopic tower, at the outer end of which a boom pivot piece is articulated, to which an outer boom part is articulated, if necessary via a boom center piece. A guy rope runs from a fixed point on the rotating platform supporting the tower over two anchor points attached in the area of the tower top.

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directed supports to a fixed point on the boom-side support, to which two further guy ropes are attached, one of which is led to a fixed point on the boom pivot piece and the other via at least one further support to a fixed point on the outer boom part, in such a way that the crane can be brought into its erected operating position by telescoping the tower.

In such self-assembling tower cranes, the boom pivot piece is folded onto the telescoped tower in the transport position and the outer boom piece is folded back onto the boom pivot piece. In a three-part boom, the boom pivot piece, the boom middle piece and the outer boom piece are folded together in a zigzag shape. An articulated connection can be made between the boom pieces, which have lower and upper chords and consist of lattice girders, in such a way that they are articulated to their lower or upper chords. The freely unfolding upper and lower chords, which are not provided with articulated parts, are then provided with stops on their front surfaces so that they can support each other in the area of their extended state. However, if such support is provided in addition to the guying, statically indeterminate systems result when the boom is assembled, which should generally be avoided.

The object of the invention is therefore to provide an easily assembled tower crane of the type specified at the outset, the boom of which represents a statically determined system when assembled.

Furthermore, a very simple and at the same time very safe boom unfolding and folding should be achieved.

According to the invention, this object is achieved in that a short boom section is connected between the boom pivot piece and the further boom section, which is connected with its upper chord in an articulated manner to the boom pivot piece and its lower chord in an articulated manner to the further boom section and is provided with stop

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pieces on the front sides of the remaining upper and lower chords, which lie against one another in the area of an approximately extended position of the boom pieces at the attachment points of the lower chords of the boom pivot piece and the short boom piece.

In the tower crane according to the invention, the lower chords of the boom pivot piece and the short boom piece support each other when the boom is assembled. In contrast, the bracing is designed in such a way that the upper chords of the short boom piece and the other boom piece do not support each other, so that a gap remains between them. This gap relieves the joint between the upper chords of the short boom piece and the boom pivot piece. The articulated connection in the area of the lower chords of the short boom piece and the other boom piece creates a favorable, statically determined system that leads to favorable stress and loading of the individual crane parts. The attachment point between the upper chords of the short boom piece and the other boom piece is only used during transport and when assembling the boom.

However, in order to prevent an undesirably large gap from forming between the stop pieces of the upper chords of the short boom section and the further boom section during assembly, a further embodiment of the invention provides that a tension element limiting the swivel angle, e.g. a latch provided with an elongated hole, is arranged between the stop pieces of the upper chords of the short boom section and the further boom section.

According to a preferred embodiment of the invention, it is provided that the further boom section is a boom middle section, to the lower chord of which an outer boom section is connected in an articulated manner, that the upper chords of the boom middle section and the outer boom section are provided with stop pieces which lie against one another in the region of their extended position, and that a guying element is connected from the fixed point of the support, instead of to a fixed point on the boom middle section, over the support in the region between the boom articulation piece and the boom.

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ger middle section and over a support in the area between the boom middle section and the outer boom section to a fixed point on the outer boom section. According to this design, it is also provided that when the boom is braced, a gap remains between the stop pieces of the upper chords of the boom middle section and the outer boom section, so that a statically determined system is created.

According to a further preferred embodiment, a support provided with a catch fork is arranged in the end region of the boom center piece, which catches itself with a holding piece of the guy element during the boom unfolding. This support provided with the catch fork is an auxiliary support during the unfolding of the boom, which brings about the necessary transfer of the guy element between the boom center piece and the outer boom piece. The holding piece can be a hinge pin between two rods forming the guy element. The support provided with the catch fork is expediently provided with a holding device which holds it in such a state that the catch fork comes into engagement with the holding piece again when the boom is folded up.

The support can also be designed as a telescopic rod, in which case the safety fork can be omitted by permanently connecting the upper support point to the guying point. This solution is safer because the intervention of a safety fork is not required. The telescopic support part guarantees that the corresponding boom guying point hits the support safely during boom assembly.

According to a further preferred embodiment, the geometric arrangement of the support and boom articulation points is selected in such a way that the guy wires are always in an almost stretched form in the operating, assembly and transport positions, so that they can also be designed as ropes which, on the one hand, cannot get tangled anywhere during assembly due to their stretched form and, on the other hand, prevent lateral movement.

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The boom sections can be easily pivoted together. This design creates a very lightweight and cost-effective guying system.

According to a further preferred embodiment, it is provided that an assembly cable, usually provided with an assembly winch, runs over a roller of the support between the boom pivot piece and the boom center piece to a fixed point on the boom center piece.

According to a further embodiment, the assembly rope has a load-bearing function even when the boom is extended and holds the boom center section as a third boom guy at an end point during crane operation, so that the upper chord attachment point between the boom center section and head section is without contact when the boom is extended. This avoids a statically indeterminate system.

An embodiment of the invention is described below with reference to the drawing
explained in more detail. In this

Fig. 1 is a side view of a bottom rotating self-assembling

the tower crane in the erected state in a schematic representation,

Fig. 2 is a side view of the tower crane according to Fig. 1 in its

folded transport condition on a crane vehicle,

Fig. 3 a front view of the folded mobile

Tower crane according to Fig. 2,

Fig. 4 to Fig. 8 show the tower crane according to Fig. 1 to 3 in different states during its erection,

Fig. 9 the boom shortly before reaching its assembled end position

ment,

Fig. 10 the boom according to Fig. 9 in its assembled end position and

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&bull; φ φ

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Fig. 11 the boom in the assembled end position, in which the boom

The middle section is additionally held in place by the mounting rope.

The bottom-spinning tower crane shown schematically in Fig. 1 consists of a platform 1 supported on the ground, which, as can be seen from Figs. 2 and 3, can also be replaced by the undercarriage of a mobile crane, which is supported in its operating position by extendable supports, and of an upper carriage or slewing platform 3 mounted on the platform 1 or undercarriage via a slewing connection 2. A lower tower section 4 is connected to the slewing platform 3, from which an upper tower section 5 can be telescoped out and in by drive means, for example a pulley block. The tower 4, 5 can be pivoted between its transport position on the slewing platform 3 and its erected position shown in Fig. 1, this pivoting usually being carried out by an assembly pulley block and the support struts 6 and 7 articulated on both sides guide the tower during the assembly process. In the erected position, the tower 4, 5 is locked to the rotating platform 3 by a bolt 100 on the base. A tension element 9 is connected to a fixed point 8 on the rotating platform 3, which runs to a fixed point 10 of a rear support 11, which is connected to the boom pivot piece 13 in the area of the tower tip in the joint 12. A further support 14 is hinged in the joint 12, from whose outer fixed point 15 a tension element runs to the fixed point 10 of the rear support 11, which can consist, for example, of two guy rods 17, 18 connected by the joint 16. A tension element 20, which can consist of a rope or a telescopic rod, runs from the fixed point 15 to the fixed point 21 in the end region of the boom pivot piece 13. A guy line also runs from the fixed point 15 to the fixed point 23 on the outer boom part 24, whereby the guy line can consist of foldably connected rods 25, 26 or ropes 27, 28. In addition, the rod 25 is designed here as a telescopic rod.

The bracing 25, 26, 27, 28 between the fixed point 15 on the support 14 and the fixed point 23 on the outer boom section 24 runs over fixed points of the intermediate supports 50 and 51, of which the support 50 is hinged on the hinge axis

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the joint 54 between the boom pivot piece and the boom center piece and the support 51 is pivotally connected to the end region of the boom center piece 33.

The rear guy 9 can also consist of a rope or of rods 30, 31, 32 connected to one another in an articulated and/or telescopic manner.

As can be seen from Fig. 1, the boom section 24 connected to the boom center section 33 can also be luffed via the assembly winch 34, the cable 35 of which runs in the manner shown over rollers to the fixed point 36 on the boom center section 33.

The tower crane shown in Fig. 1 can be brought into its operating position by erecting the tower 4, 5 and then telescoping out the outer tower part 5.

Fig. 2 shows the tower crane shown schematically in Fig. 1 as a mobile crane in its transport position. The undercarriage 1 of the mobile crane consists of the chassis, which is provided with extendable supports 40. In the transport position shown in Figs. 2 and 3, the boom pivot piece 35 is folded onto the telescoped tower 4, 5. The boom middle section 33 folded back onto the boom pivot piece 35 is folded laterally onto the boom pivot piece 35 in order to reduce the transport height of the mobile crane in the transport position. The outer boom part 24 is folded onto the boom middle section 33 around a cross joint located in the area of the base belts.

Fig. 4 to 7 show the tower crane in different states during its erection.

Fig. 4 shows the tower pivoted at an angle of about 60 degrees to the rotating platform, to which the zigzag-folded boom parts are folded onto the tower. The boom center section 33 and boom part 24 are still

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attached to the side of the boom linkage 13 to reduce the transport height. The rear guying 9 is still without tension, whereby some of the rods forming the guying are still lying at an angle on top of each other.

In the position shown in Fig. 5, the tower is fully erected and locked to the rotating platform. The rear guy 9 is in the extended state, so that by further telescoping the inner tower section 5 from the outer tower section 4, a tension is exerted on the boom which unfolds the boom via the guy 9. In the position shown in Fig. 5, the boom center section 33 has been rotated relative to the boom articulation piece 13 about an axis parallel to the two boom sections into a position in which the heights of the profiles or the center planes of the boom sections are aligned with one another. After loosening the upper joint between the boom articulation piece 13 and the boom center section 33, which allows the two boom sections to rotate about an axis parallel to these, the boom center section 33 is lowered relative to the boom articulation piece 13 in the manner shown in Fig. 6. This lowering is done in a known manner via the mounting part 35 with the aid of the mounting winch 34.

Before further telescoping of the tower, the part 33 must be lowered to such an extent that the supports 12 and 14 can unfold past the boom part 33 (see Fig. 7).

Fig. 7 shows the increasing unfolding of the guy wires as the inner tower section 5 is further telescoped out.

Fig. 8 shows the state after further telescoping of the inner tower section 5 and simultaneous unwinding of the assembly cable 35 by the assembly winch 34; the boom part 33 must always be inclined slightly to the right so that it does not fall onto the boom part 13.

As can be seen from Fig. 9, a short boom piece 52 with a similar profile is connected between the boom pivot piece 13 and the boom center piece 33.

This short boom section 52 is connected to the upper chord or chords, depending on whether the boom sections consist of lattice girders with a triangular or square profile, of the boom articulation section 13 by the joint with the joint axis 54.

The short boom section 52 is connected with its lower chord supports to the lower chord supports of the boom center section 33 by a joint with the joint axis 55. The lower chord supports of the boom pivot piece 13 and the short boom section 52 are provided with stops 56, which rest on one another when the boom is extended. In a corresponding manner, the upper chord support or supports of the short boom section 52 and the boom center section 33 are also provided with stops 57, which mostly rest on one another during boom deployment and in the transport state. Since tensile forces can also occur at this upper chord point during boom assembly, the upper chord supports of the short boom section 52 and the boom center section 33 are connected to one another by a tension member or a bar with a slotted hole guide in such a way that the stops 57 can only move away from one another by forming a relatively narrow gap. When the boom is extended (working position), the slotted hole connection is neither in tension nor in compression contact; i.e. the upper chord point 57 is then free of force.

In a corresponding manner, the outer boom section 24 is also connected to the boom center section 33 by an articulated connection of the lower chords with the articulated axis 58. The upper chord supports are provided with stops 59 on their front sides, which rest against one another in the area of the extended state.

In order to create a statically determined system, the components are designed in such a way that in the operating state shown in Fig. 1, there is a gap between the upper chord of the boom center section 33 and the short boom section 52 on the one hand, i.e. the stops 57 do not rest on each other and on the other hand the upper chord stops 59 rest on each other between the upper chord of the boom part 33 and 24.

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-&Igr;&Ogr; &Igr; If in the embodiment according to Figs. 9 and 10 the boom is completely unfolded into its operating position, the assembly cable 35 becomes slack in the manner shown.

In the area of the outer end of the boom center section, a pivotable auxiliary support 60 is mounted, which is provided with a catch fork 61 at its outer end. This auxiliary support 60 serves to transfer the guy rope over the articulated connection between the boom center section 33 and the outer boom section 24 when the boom sections are unfolded and folded together. The catch fork engages in a joint axis 62 which connects the guy rods 27 and 27". In the assembled position of the crane, the auxiliary support 60 remains in a position in which it comes into engagement with the joint axis 62 again when the crane is folded together. The position and component lengths of the supports 51, 60 and the boom guy rods 27, 28 are selected according to the invention such that the guy rods 27 and 28 are stretched out during crane operation and in the assembly and transport position to prevent these guy rods from becoming tangled with other components (see e.g. Fig. 7). This also means that the guy rod 27 can be used as a rope in a cost-effective and weight-saving manner. executable because it also makes it easy to fold the boom part 33 sideways onto the boom part 13 (as shown in Fig. 3).

In the embodiment according to Fig. 11, the assembly cable 35 takes on a supporting function in the operating position of the crane, i.e. when the boom is unfolded. In order to fulfill this function, the assembly winch 34 must be appropriately dimensioned and locked in operation. In order to ensure a statically determined system, however, the following modification to the system according to Fig. 1 or Fig. 10 is necessary: A gap must be formed between the stops 59 of the upper chords of the boom center section 33 and the outer boom part 24 when the boom is extended in the working position. The upper chord contact point formed by the stops 59 is not present in the arrangement shown in Fig. 11.

required and serves only as a safety element in the event that the assembly and holding cable 35 should break, in order to prevent the boom from falling.

Claims (8)

1. Guyed tower crane with a boom pivot piece ( 13 ) hinged to the tower top, to which another boom piece ( 33 ) is hingedly connected,
with a rear guy element ( 9 ) which runs from a fixed point ( 8 ) on a rotating platform ( 3 ) to a fixed point on a support ( 11 ) hinged in the region of the tower top, and
with two further guy elements which run from a fixed point of the support or a fixed point ( 15 ) of a further support ( 14 ) hinged in the area of the tower top, which is connected to the first support ( 11 ) by a tension element, to fixed points ( 21 , 23 ) on the boom linkage piece ( 13 ) and a further boom piece ( 24 ), characterized in that
that a short boom section ( 52 ) is connected between the boom articulation piece ( 13 ) and the further boom section ( 33 ), which is connected with its upper chord in an articulated manner to the boom articulation piece ( 13 ) and its lower chord in an articulated manner to the further boom section ( 33 ) and is provided with stop pieces ( 56 , 57 , 59 ) on the front sides of the remaining upper and lower chords, which lie against one another at the articulation points ( 56 , 59 ) in the region of an approximately extended position of the boom sections. 2. Tower crane according to claim 1, characterized in that between the stop pieces ( 57 ) of the upper chords of the short boom section ( 52 ) and the further boom section ( 33 ) a tension element which limits the swivel angle, e.g. a bar provided with an elongated hole, is arranged, which can come to rest on the right and left side in the crane transport position and during boom assembly and which is without contact during crane operation. 3. Tower crane according to claim 1 or 2, characterized in that the further boom section is a boom middle section ( 33 ), to the lower chord of which an outer boom section ( 24 ) is connected in an articulated manner,
that the upper chords of the boom center section ( 33 ) and the outer boom section ( 24 ) are provided with stop pieces ( 59 ) which lie against one another in the region of their extended position, and
that a guy element runs from the fixed point ( 15 ) of the support ( 14 ) instead of to a fixed point on the boom center piece, over the support ( 50 ) in the area between the boom articulation piece and boom center piece, and over the support ( 51 ) in the area between the boom center piece and the outer boom piece, to a fixed point ( 23 ) on the outer boom piece ( 24 ). 4. Tower crane according to one of claims 1 to 3, characterized in that one or more supports are arranged in the end region of the boom center section in such a way that the boom guying guided over these is always kept at a sufficient distance from the boom during boom deployment so that the deployment process does not come to a halt. 5. Tower crane according to one of claims 1 to 4, characterized in that a telescopic mounting support ( 60 ) provided with a catch fork ( 61 ) is arranged in the end region of the boom center section ( 33 ), which in the design system with catch fork hooks into a holding piece ( 62 ) of the guying element ( 27 ) during boom deployment and which in the design system as a telescopic rod always remains firmly connected to the boom guying point ( 62 ). 6. Tower crane according to one of claims 1 to 5, characterized in that the geometric arrangement of the support and boom articulation points, in particular for the components ( 50 , 51 , 61 , 52 , 33 , 24 , 27 , 28 , 62 ) is selected such that the guy wires ( 27 , 28 ) are always present in an almost stretched form in the operating, assembly and transport positions, so that they can also be designed as cables which, on the one hand, cannot get tangled anywhere during assembly due to their stretched form and which, on the other hand, enable the jib part ( 33 ) to be pivoted sideways to the jib part ( 13 ) in a simple manner. 7. Tower crane according to one of claims 1 to 6, characterized in that an assembly cable ( 35 ), usually provided with an assembly winch ( 34 ), runs over a roller of the support between the boom articulation piece ( 13 ) and the boom center piece ( 33 ) to a fixed point ( 21 ) on the boom center piece ( 33 ). 8. Tower crane according to one of claims 1 to 7, characterized in that the assembly cable ( 35 ) has a supporting function even when the boom is extended and holds the boom center piece ( 33 ) as a third boom guy in the end point ( 36 ) during crane operation, so that the upper chord attachment point ( 59 ) is then without contact in the extended state of the boom.