Crane with variable-amplitude boom extension and method of installing variable-amplitude boom

Abstract

The invention relates to a crane, in particular a mobile crane, having a main boom (1), a luffing boom (13) which is hingedly connected to the main boom in a luffable manner and is composed of a hinge (6) and at least one luffing boom element, and a luffing boom cable which extends from at least one cable carrier (5) to the luffing boom tip, wherein the luffing boom cable comprises at least one branching device in order to branch off an assembly cable element (8) from the luffing boom cable, which is fastened or fastenable at the end to the luffing boom hinge for the assembly of the at least one luffing boom element.

Description

TECHNICAL FIELD

[0001] The invention relates to a crane, in particular a mobile crane, having a main boom, a luffing boom which is articulated in a variable width to the main boom and a luffing boom cable, the luffing boom consisting of an articulated piece and at least one luffing boom element, the luffing boom cable extending from at least one cable carrier to a luffing boom tip. The invention also relates to a method for installing such a crane. BACKGROUND

[0002] Generally, the assembly of lattice booms requires a little more space than the arm length of the entire system calculated from the center of rotation. This applies both to pure main boom systems and to systems consisting of a main boom and a luffing boom, since here the entire boom system is generally stretched out on the ground for assembly and only erected in a second step.

[0003] This is disadvantageous in the case of spatial conditions where the application site is narrow, so that it is desirable to assemble the luffing boom while the main boom is luffed upward. SUMMARY

[0004] It is an object of the invention to provide a suitable crane which occupies less crane scaffold space by assembling the luffing boom while the main boom is being erected.

[0005] This object is achieved by a crane according to one aspect of the invention and by a method according to another aspect of the invention. Advantageous designs of the above-mentioned crane and the method are further aspects of the invention.

[0006] The luffing system installation method according to the invention requires only the length of the main boom and the luffing assembly unit as a space requirement, so that approximately 20-40% less space can be saved compared to known methods. This can be a decisive factor when the space is limited, for example when used near industrial facilities, in forest areas or on mountain tops.

[0007] It is important for the implementation of the method of the invention that the luffing boom cable of the crane according to the invention comprises at least one branching device which, by means of an assembly cable, in particular a cable, effects the additional connection of the luffing boom cable to the already installed articulated piece of the luffing boom. The luffing movement of the luffing boom is in particular controlled by means of the luffing boom cable by means of a luffing cable acting on the cable carrier. When the luffing boom cable itself is not yet assembled or not completely assembled, the adjustment force of the luffing cable can also be applied to the already assembled articulated piece of the luffing boom by means of the branching device. Due to the additional assembly cable element, this force can at least temporarily be used for the installation to act directly on the articulated piece.

[0008] Regardless of whether the luffing boom cable is single-stranded or multi-stranded, the term "cable carrier" is used in the following. If there are two cable strands / struts on the crane that extend parallel to each other, a cable carrier is usually used, which can accommodate both parallel strands. If the cable is single-stranded, only a beam top pulley is used. For the sake of simplicity, the cable carrier is referred to in the following regardless of whether the cable is single-stranded or multi-stranded.

[0009] The luffing boom is formed from a plurality of luffing boom elements, which are successively assembled to form the boom length. The first element, which is pivotably articulated to the tip of the main boom, is referred to as the hinge. The last element is referred to as the head, which usually has the necessary pulleys for deflecting the hoisting ropes.

[0010] A great advantage of the structure according to the application is that for the crane assembly, only the hinge has to be installed on the ground when the main boom is luffed down. All other sub-sections of the luffing boom can then be installed in the air when the main boom is luffed up, which brings the above-mentioned advantages in terms of space requirements. This is due to the assembly cable element, as this not only ensures sufficient stability of the hinge, which has not yet been reinforced, but at the same time also allows active adjustment of the hinge for alignment.

[0011] The crane is preferably a mobile crane with a main boom, in particular with a lattice structure of the main boom, and a lattice extension, which is luffably articulated on the main boom. Due to the lattice structure of at least the luffing boom, it can be successively assembled in individual segments. If there is a requirement for the total length of the boom system, the crane can also have a jib structure. However, the crane can also have a telescopic boom as the main boom, on which the luffing boom is mounted. By means of the telescopic boom, there is an additional "telescoping" degree of freedom during assembly.

[0012] The branch device is preferably introduced into the luffing boom cable at a position close to the cable carrier. It is conceivable that the branch device is already connected to the cable carrier by at least one first strut or exactly the first strut. The subsequent struts are thus connected to the first strut by means of the branch device.

[0013] The at least one first strut and / or the subsequent struts are preferably articulated to the branch device. The assembly cable element can also be rotatably attached to the branch device. It is particularly preferred that the first strut connects the branch device to the cable carrier, which is articulated to the branch device about a rotation axis extending parallel to the luffing plane. The subsequent struts and / or the assembly cable are preferably articulated by means of a rotation axis extending transversely to the luffing plane. The subsequent struts and the assembly cable element can be mounted about a common rotation axis, but separate connection points are preferred. The combination of the first strut and the branch device can also be ideally designed as one component.

[0014] The connection of the branching device to the assembled cable device and to the strut is preferably achieved by means of corresponding connection tabs which are held in place at the end of the strut and / or of the assembled cable device.

[0015] The luffing arm cable, as is customary in large arm systems, can preferably be designed as a multi-strand, in particular as a double-strand. In this case, the branching device preferably comprises a crossbar which connects the parallel running cable strands, at the outer ends of which connection points for the articulation of the strut or of the assembled cable element are provided. In this case, it is preferably also provided that two assembled cable elements running parallel to one another are articulated at the ends on the crossbar and act on the top beam of the articulation, in particular on the corresponding corner post. The combination of the first strut, the branching device and the crossbar can be designed as a single assembly.

[0016] In addition to the crane according to the invention, the invention also relates to a method for mounting a luffing arm at the tip of a main arm of a crane according to the invention or of an advantageous embodiment of the invention. The method is distinguished by at least the following steps:

[0017] Assembling a luffing arm articulation comprising a luffing adjustment device, the luffing adjustment device comprising at least one cable carrier on the main arm,

[0018] Mounting the assembled cable element on the cable element of the luffing arm cable running from the cable carrier by means of the branching device and fastening the assembled cable element on the luffing arm articulation,

[0019] Lifting the main arm and folding the luffing arm articulation down by means of the luffing adjustment device in order to mount at least one luffing arm element on the articulation, and

[0020] Lengthening and connecting the luffing arm to the mounted luffing arm head part.

[0021] For the method claimed, it is important according to the invention that the main arm is first luffed upwards in order to assemble further elements of the luffing arm. The space required for the arm assembly is therefore significantly reduced, which makes it possible to use the crane even on a narrow construction site. Since the articulation or the assembled luffing arm part is simultaneously controlled to fold down, it is possible to first pre-assemble further luffing arm elements horizontally from the ground, in particular by inserting the bolts of the top beam. The main arm can then continue to luff upwards while the element to be assembled at the moment is supplemented, so that it is automatically aligned with the assembled part of the luffing arm. The remaining bolts can then be inserted into the bottom beam.

[0022] The crane can have a lattice main boom or a telescopic boom. In the case of a telescopic boom, in addition to the "upward luffing" degree of freedom of the main boom, a telescoping degree of freedom will be added. The assembly of the luffing boom 13 will start with the main boom as retracted as possible, then, in addition to the upward luffing of the main boom (method step c.), the necessary telescoping will always be performed if necessary. This is done to obtain the required distance away from the ground.

[0023] The assembly of the luffing boom cable elements for the elongation of the luffing boom cable starting from the branch device is preferably carried out in parallel or slightly delayed. It is conceivable that the luffing boom cable elements are received by the auxiliary crane and mounted in a suspended state on the working platform. The already mounted luffing boom cable elements are preferably hanging loosely from the branch device, almost vertically downward toward the ground.

[0024] The connection of the assembled luffing boom cable elements of the luffing boom cable to the head part of the assembled luffing boom is carried out last. For this purpose, it is advantageous if the luffing boom is first luffed upward by the luffing adjustment device together with the assembly cable elements until the elongated luffing boom cable is luffed almost vertically downward over the attachment point of the luffing boom head part. The main boom is then luffed downward until the luffing boom is supported by its head part on the ground and / or the roller carriage standing on the ground. This measure relieves the assembly cable elements of the load, and the luffing boom is now fully supported on the ground. By actuating the luffing adjustment device, in particular the cable carriage, the luffing boom cable can now be lowered until the last cable element can be attached to the assembly point of the head part. The assembly cable elements can now be released and optionally unhooked, or alternatively remain mounted on the luffing boom as additional auxiliary cable.

[0025] Since the hoisting cable can only be routed later on the beam top pulley of the luffing boom, which is installed later, it must first be lowered from the main boom tip after the luffing boom has been installed. In order to increase the inherent weight of the cable, it is proposed to install a weight, for example a hoisting hook, on the hoisting cable of the crane before the main boom is erected and the luffing boom articulation is folded down. After the luffing boom and the luffing boom cable have been assembled, the main boom can be luffed upward and the luffing boom can be luffed downward until the hoisting cable of the hoisting hook, which has been installed, can be lowered vertically to the beam top pulley of the luffing boom head. The hoisting hook can then be replaced by a hook trolley. BRIEF DESCRIPTION OF DRAWINGS

[0026] Further advantages and features of the application will be explained in more detail using the embodiments shown in the figures. Shown in the figures are:

[0027] Figures 1 to 7 a schematic side view of a crane according to the application in time sequence when assembling a luffing system by a method according to the application,

[0028] Figure 8 a schematic side view of a crane according to the application in time sequence when assembling a luffing system by a method according to the application,Figures 1 to 7 Detail view of the luffing adjustment device of the crane,

[0029] Figure 9 Detail view of the luffing adjustment device according to Figure 8

[0030] Detail view of the luffing adjustment device according to Figure 10

[0031] Detail view of the luffing adjustment device according to Figure 11 Figure 10 Detail view of the luffing adjustment device according to

[0032] Figure 12 Detail view of the luffing adjustment device according to DETAILED DESCRIPTION

[0033] The mobile crane according to the application is shown in Figures 1 to 10 The mobile crane comprises a luffing lattice main boom 1, at the tip of which a luffing boom 13, also composed of lattice elements, can be mounted, as shown in detail in Figure 7 The traction of the main boom 1 takes place by means of a jib la 1a. For the traction of the luffing boom 13, two cable carriers 4, 5 are pivotably mounted about a horizontal axis between the main boom 1 and the luffing boom 13, the cable carriers being connected at the end by means of a luffing adjustment device 12, the length of which is variable. Furthermore, a strut 9 extends from the upper cable carrier 5 to the head of the luffing boom 13. The hoisting cable with the hook trolley 20 attached thereto is identified by the reference 11.

[0034] The structural details of the crane are described below in the context of the method according to the application for mounting the luffing boom on the main boom 1. Figures 1 to 7 The individual steps to be carried out for the assembly of the luffing boom 13 in the suspended state are shown schematically in chronological order.

[0035] The description of the method according to the application is based on a main boom 1 which has already been preassembled, which can be assembled horizontally according to the usual procedure. The luffing assembly unit 2, which can be seen in detail in Figure 8 and Figure 9 is subsequently mounted on the tip of the main boom. The unit 2 consists of two cable carriers 4, 5, the lower carrier 4 being pivotably articulated to the tip of the main boom, while the second carrier is pivotably mounted about a parallel axis on the articulation 6 of the luffing boom 13.

[0036] The two cable carriers are connected at their free ends by means of a luffing cable 12, which, in the assembled crane state, can adjust the luffing angle of the luffing boom 13 by means of the strut 9 which is subsequently assembled. In a first assembly step, the luffing assembly unit 2, consisting of the cable carriers 4, 5 and the articulation, is first assembled on the main boom 1.​

[0037] Furthermore, a first strut 9 has been mounted on the upper carriage 5. As Figure 10 illustrated, a rocker 91 is attached at the free end of the upper carriage. The rocker 91 serves as a coupling element between the first and second strut 9, 9', but also as a conversion piece in order to branch off the assembly cable 8 from the guy cable additionally.

[0038] Since the guy cable for the luffing arm 13 consists of two guy cable strands extending in parallel, each with a corresponding strut 9', 9", 9"', the rocker 91 is formed by a crossbar 92 extending transversely to the luffing plane, at the end of which corresponding connection points are provided for mounting the struts 9, 9' of the individual strands in a hinged manner. In particular, the first strut 9' is pivotably hinged at the end of the crossbar 92 about a rotation axis extending parallel to the luffing plane. In contrast, the strut 9" extending from there in the direction of the luffing arm head is pivotably hinged at the end of the crossbar 92 about a rotation axis extending transversely to the luffing axis. The same applies to the two assembly cables 8 extending parallel from the crossbar 92, but the assembly cable hinge points are further out than the strut 9'. The structure of the rocker 91 is designed in such a way that the assembly cables 8 and the struts 9" can swing past each other without any problems. For the sake of simplicity, only one strand is referred to in the following, i.e. the corresponding struts and assembly cables 8 are referred to in the singular. However, it is clear that the statements in this respect always refer to both strands. The combination of the rocker 91, the crossbar 92 and the first strut 9 can be designed as a structural unit.

[0039] After assembly of the luffing assembly unit 2, the luffing adjustment 12 for the luffing arm 13 is first retracted, and the assembly cable 8 is connected to the first strut 9' by means of the rocker 91 and thus also indirectly to the WA carriage 5. The other end of the assembly cable 8 is connected to the luffing arm hinge 6, approximately at the end of the luffing arm hinge 6 in the region of the top beam or the corresponding corner post.

[0040] In the next step, as Figure 2 illustrated, the guy carriage 4, 5 is erected, and the lifting hook 10 is attached to the lifting cable 11. The main arm 1 can then be erected to an angle, while the hinge 6 is controlled to fold down. This can be achieved by changing the length of the luffing adjustment 12 and by the force transmitted to the hinge by the assembly cable 8.

[0041] As Figure 3As shown, the assembly of the first intermediate piece 7 of the luffing arm 13 can be started at this position. For this purpose, the intermediate piece is laid on the ground such that the upper bolts can be inserted between the hinge 6 and the intermediate piece 7. The intermediate piece 7 can then be erected by further luffing of the main arm, for which purpose the intermediate piece 7 can be supplemented as known by means of a supplementary crane, and can then be installed in a suspended manner by bolting the lower bolts together. The guy ropes are then extended by installing further struts 9" and 9"'. The struts 9", 9"' are received in a stop device on the supplementary crane and assembled from the working platform.

[0042] The assembly of a further intermediate piece 7' (see Figure 4 ) and the head piece 30 of the luffing arm 13 is similar to the first intermediate piece 7. The assembled part of the luffing arm 13 remains in a substantially vertical alignment, with the assembled guy ropes cables 8 always under tension. This is the only way to achieve the defined positioning of the intermediate pieces 7 of the luffing arm 13 already installed by means of the luffing adjustment device 12. The further W-struts 9", 9"' are also assembled in a similar manner to the procedure described above.

[0043] When all intermediate pieces 7, 7' and head pieces are installed, the guy ropes must still be installed on the head piece of the luffing arm 13. For this purpose, the luffing arm 13 is luffed slightly upwards with the aid of the luffing adjustment device 12 and the guy ropes cables 8. The luffing is upwards until the guy ropes or the bottom strut 9"" is vertically above its bolting point on the head piece 30 of the luffing arm 13. By subsequent luffing downwards of the main arm 1, the head piece 30 is brought into the defined position, for example on the ground 109 or on the roller carriage 110. The luffing arm 13 is now supported in the region of the head piece 30 on the main arm 1 and in its luffing axis, whereby the simultaneously assembled guy ropes cables 8 are loosened (see Figure 5 、 Figure 6 ).

[0044] By further luffing downwards of the guy rope carriage 5, the struts 9 can be lowered further in order to install the lowest strut 9"" at the bolting point of the luffing arm 13. This installation does not require additional operating equipment. The horizontal displacement of the bolting points required for establishing the connection to the head piece 30 is minimal, given the large tensioned length from the respective struts 9', 9", 9"', 9"".

[0045] After the guy ropes have been bolted, the lifting hook 10 can be lowered and the lifting cables can be wound onto the hook pulley 20 placed on the ground 109 (see Figure 6). For this purpose, some assembly space is preformed by simultaneously luffing the main boom 1 upwards and the luffing boom 13 downwards. Thereby the load hook 10 can be vertically lowered in the direction of the beam top pulley (Nackenrolle) 111 of the head piece 30. In order to be able to completely lower the load cable 11, the load hook is pre-installed as a weight 10. If the load cable is wound on the belt hook trolley 20, the final setup of the crane can continue as known from the prior art and the main boom 1 can be completely erected.

[0046] In Figure 11 a slightly modified embodiment of the branching device is shown. Although the stay cable is designed in a multi-strand design, here only one assembly stay cable 8 is used. In this case, the assembly stay cable is hingedly mounted in the middle of the crossbar 92 between the struts 9'. In Figure 12 another alternative is shown in the embodiment, which can be used for cranes with a single-strand stay cable. However, in the variant shown here, the single-strand stay cable is connected to the hinge 6 by two assembly stay cables 8 extending in parallel.

[0047] The technical features and advantages of the method and the crane according to the invention can be briefly summarized as follows:

[0048] - The assembly stay cable 8 forms a defined geometry between the stay cable frame 5 and the hinge 6 during assembly. The angle between the components can be actively influenced. Without the assembly stay cable 8, the relative angle between the stay cable frame 5 and the hinge 6 can become too large, so that with the method an increased safety can be ensured and damage to components can be avoided.

[0049] - The struts 9 and the assembly stay cable 8 can swing past each other during assembly. This can be achieved by a rocker 91 on the stay cable frame 5 with two connection tabs, one for the strut 9',

[0050] 9" and one for the assembly stay cable. For example, the strut 9" is located Figure 2 on the left side of the assembly stay cable 8 in Figure 3 and the strut 9" is pivoted to the right side in

[0051] - The assembly stay cable 8 is not tensioned during crane operation, but can also be designed as a load-bearing element during operation as a variant. The assembly stay cable 8 can then act as an additional stay cable during operation.

[0052] - The main boom length must be greater than the luffing boom length so that the luffing boom 13 can hang vertically downwards. In principle, the method can be used with or without a jib 1a, which is necessary for longer arm combinations due to the required restoring moment. However, this is not relevant to the method according to the invention.

[0053] - To close the head piece 30 of the yoke 13 with the dragline, the yoke 13 can be stopped on the ground 109 or placed on the roller stand 110.

Claims

1. A crane comprising a main boom, a luffing jib articulated to the main boom in a variable-luffing manner, and a luffing jib cable, wherein the luffing jib comprises an articulated part and at least one luffing jib element, and the luffing jib cable extends from at least one cable bracket to a luffing jib tip. It is characterized by: The luffing jib cable comprises at least one branching device for branching off an assembly cable element from the luffing jib cable, the assembly cable element being fastened or fastenable at one end to a luffing jib hinge for assembling the at least one luffing jib element, The branching device comprises a beam connecting parallel-extending strands of the luffing jib cables, at the outer ends of which connection points for connecting the luffing jib cables and cable elements of an assembly cable element are provided.

2. The crane according to claim 1, characterized in that The branching device is introduced into the luffing jib cables in the region of the guy brackets.

3. Crane according to any one of the preceding claims, characterized in that The assembly cable element and / or the cable element of the luffing jib cable extending toward the luffing tip are articulated on the branching device in a pivotable manner about a rotation axis extending transversely to the luffing plane.

4. The crane according to claim 1, wherein: The assembly cable element and the cable element of the luffing jib cable extending towards the luffing tip are hinged to the branching device via separate pivot axes.

5. The crane according to claim 1, wherein: A first cable element of the luffing jib cable extending toward the cable holder is hinged to the branch device around a rotation axis extending parallel to the luffing surface.

6. A method for mounting a luffing jib at the tip of a main boom of a crane according to any one of the preceding claims, characterized by the following steps: a. Assembling a luffing arm hinge, the luffing arm hinge comprising a luffing adjustment device, the luffing adjustment device comprising at least one guy wire rack on the main arm, b. installing the assembly cable element on the cable element of the luffing jib cable extending from the cable rack through the branch device, and fastening the assembly cable element to the luffing jib hinge member, c. raising the main boom by means of the luffing adjustment device of the luffing boom and folding down the luffing boom joint to mount at least one luffing boom element on the joint, and d. Extend and connect the luffing jib cables to the assembled luffing jib head.

7. The method according to claim 6, characterized in that One or more cable elements for extending the luffing jib cables are received and installed by an auxiliary crane.

8. The method according to claim 6 or 7, characterized in that The at least one luffing jib element is first connected to the articulated part or the assembled luffing jib element by means of upper bolts and then supplemented by the auxiliary crane.

9. The method according to claim 6, characterized in that To connect the luffing jib cables to the head piece, the luffing jib is luffed upwards by means of the luffing adjustment device and the assembly cable elements until the extended luffing jib cables are positioned vertically above their attachment points on the luffing jib head piece and, by subsequent luffing of the main boom, the luffing jib is placed and supported by its head piece on the ground and / or on a roller frame.

10. The method according to claim 6, characterized in that Before the main boom is raised and the luffing jib articulation is folded downward, a lifting hook is installed on the lifting cable of the crane, and after the luffing jib and the luffing jib cables are assembled, the main boom is luffed upward and the luffing jib is luffed downward so that the lifting cable with the lifting hook installed can be vertically lowered to the area of ​​the beam top pulley at the head of the luffing jib.

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