Crane and method

Abstract

The present invention relates to a crane (10), in particular a mobile crane, with a main boom (1) and a luffing boom (2) pivotally mounted on the main boom (1), wherein a retaining strand (3) runs between the main boom (1) and the luffing boom (2), wherein the retaining strand (3) has a lifting element (30) that can be changed in length and can thereby be changed in length.

Description

[0001] The present invention relates to a crane, in particular a mobile crane, with a main boom and a luffing boom pivotally attached to the main boom, wherein a retaining strand runs between the main boom and the luffing boom.

[0002] It is well known that, especially in inner-city areas, space is often limited when it comes to setting up and positioning a crane, such as a crawler crane, on a construction site. A typical crane setup and a typical parking position for a conventional crane, such as the folding-knife position of the crane's boom, are often not possible under such limited space conditions.

[0003] It is therefore often necessary for the crane's luffing jib to be able to fold completely away from the main boom when attached, thus giving the crane a folding function. For example, the luffing jib is lowered into the vertical parking position daily with the main boom raised, in order to park the crane in a space-saving manner, for example overnight.

[0004] It is known that a cable pulley with multiple reeving points can be installed in the support structure between the main boom and the luffing boom, enabling the luffing boom to be fully lowered into the vertical position. This requires a special main boom head to support this folding mechanism.

[0005] A conventional crane can therefore only be converted into a crane with the described folding function through a complex conversion and / or a crane with the described folding function has a more complicated structure than a conventional crane.

[0006] Against this background, the present invention aims to improve a crane as described above, particularly with regard to simple construction and / or conversion.

[0007] This problem is solved by the subject matter with the features of independent claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

[0008] According to the invention, the retaining cord has a lifting element that can be changed in length and can therefore be changed in length.

[0009] Preferably, the support string comprises a lifting element and a main string, e.g. one or more steel cables, steel support rods and / or CFRP support rods, wherein the lifting element and the main string are connected via an adapter.

[0010] The rocker arm can also be called a rocker needle.

[0011] The main boom and the luffing boom are preferably components of a boom assembly.

[0012] The crane is preferably a mobile crane, in particular a crawler crane.

[0013] Preferably, the crane has an adjustable support link for the luffing mechanism of the crane's luffing boom.

[0014] The crane can have several lifting elements, in particular arranged in parallel.

[0015] Preferably, the lifting element is a hydraulic lifting element, in particular a hydraulic cylinder, or an electric lifting element, in particular a linear actuator.

[0016] Preferably, the lifting element is a hydraulically and / or electrically operated lifting element.

[0017] Preferably, the support string can be extended in such a way that the rocker arm can be pivoted relative to the main arm so that the rocker arm rests against the main arm.

[0018] In other words, it is preferably intended that the main boom and the luffing boom can be folded together.

[0019] Preferably, the retaining strand is attached at one end to a lower or upper area of ​​the main boom in a vertical position, with the lifting element being arranged at this end of the retaining strand.

[0020] The lifting element can alternatively be arranged or attached, for example, to the boom head, i.e., in the upper area of ​​the main boom.

[0021] Preferably, the retaining chain has locking means designed to lock the lifting element, in particular in a retracted position of the lifting element, especially in such a way that the lifting element cannot be extended.

[0022] Preferably, the locking means comprise or represent a hydraulic element, in particular a hydraulic cylinder, or an electrically operated element, in particular a linear actuator.

[0023] Preferably, the lifting element has a housing and a piston rod that can be extended from and retracted into the housing.

[0024] The adapter can be part of the piston rod.

[0025] Preferably, one or more locking tabs, each with an opening, are arranged on the housing, the piston rod having an opening, a locking element, in particular a locking bolt, is provided, the locking element being able to be guided through the opening of the locking tab or the openings of the locking tabs and the opening of the piston rod when the openings are aligned, in order to lock the lifting element in a retracted position, the locking means comprising the locking tab or locking tabs and the locking element.

[0026] Preferably, the piston rod adapter has the opening.

[0027] Preferably, the locking means include monitoring means, in particular an electromechanical switch or a proximity switch, by means of which the position of the locking means, in particular the locking element, can be determined.

[0028] The invention also relates to a method for operating a crane according to the invention comprising the following steps: Shortening the holding string by shortening the lifting element, whereby the rocker arm is swung out by an initial opening angle relative to the main arm; locking the lifting element.

[0029] Preferably, it is provided that the main boom and the attached rocker boom are first raised from a horizontal position to a vertical position.

[0030] Preferably, the crane is brought into a parking position by first bringing the crane to a state in which the main boom is in a vertical position and the luffing jib is pivoted by the initial opening angle relative to the main boom, followed by unlocking the lifting element(s) and / or extending the holding string by extending the lifting element(s), with the luffing jib being pivoted by the initial opening angle relative to the main boom so that the luffing jib rests against the main boom.

[0031] Preferably, the main boom and the luffing boom attached to it are subsequently lowered from a vertical position into a horizontal position. The invention also relates to a method for retrofitting a crane with a main boom and a luffing boom pivotally attached to the main boom, wherein a support string runs between the main boom and the luffing boom, characterized in that one or more lifting elements of variable length are introduced into the support string, so that the crane becomes a crane according to the invention.

[0032] Preferably, a conventional crane can be retrofitted in such a way that the support chain has one or more support elements that can be changed in length and thus its length can be changed.

[0033] Preferably, the complete existing boom equipment of the crane to be retrofitted can be retained. Preferably, a crane according to the invention has an identical basic machine to or similar to a conventional crane.

[0034] Preferably, when retrofitting a conventional crane, all previous functions, such as lifting operation with the main boom, two-hook operation, runner operation, and the use of the complete needle lift portfolio, are retained. Preferably, a crane according to the invention, which is newly manufactured or not created from a conventional crane by retrofitting, also has these functions.

[0035] Preferably, the support structure can be extended by means of one or two lifting elements, which are hydraulically and / or electrically operated. Preferably, the complete existing boom assembly, and thus the existing base machine of a conventional crane, can continue to be used. The base machine therefore preferably remains unchanged. Preferably, all previous functions, such as lifting operation with the main boom, two-hook operation, runner operation, and the use of the complete range of luffing jibs, are also retained. The folding function can preferably be retrofitted to the current standard.

[0036] Preferably, the rocker arm can be connected to the main arm when the rocker arm is in contact with the main arm.

[0037] It should be noted here that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this is a possible interpretation, but can also denote a plurality of elements. Likewise, the use of the plural also includes the presence of the element in question in the singular, and conversely, the singular also includes several of the elements in question. Furthermore, all features of the invention described herein can be combined with one another or claimed separately from one another as desired.

[0038] Further advantages, features, and effects of the present invention will become apparent from the following description of preferred embodiments with reference to the figures, in which identical or similar components are designated by the same reference numerals. These figures show: Fig. 1: A side view of an embodiment of a crane according to the invention. Fig. 2: A side view of an embodiment of a crane according to the invention. Fig. 3: A detail of the side view of an embodiment of a crane according to the invention. Fig. 2 Fig. 4: A side view of an embodiment of a crane according to the invention. Fig. 5: A detail of the side view of an embodiment of a crane according to the invention. Fig. 4 Fig. 6: A side view of an embodiment of a crane according to the invention. Fig. 7: A perspective view of a detail of an embodiment of a crane according to the invention. Fig. 8: A side view of a detail of an embodiment of a crane according to the invention.

[0039] In Fig. 1 Figure 10 depicts a crawler crane with a main boom 1 and a luffing jib 2. The luffing jib 2 is pivotally connected to the main boom 1. A support link 3 runs between the main boom 1 and the luffing jib 2. The main boom 1 and the luffing jib 2 are the main components of the boom assembly of the crane 10.

[0040] The lifting element 30 is connected via an adapter to a main strand, e.g. one or more steel cables, steel support rods and / or CFRP support rods, of the support strand 3.

[0041] The rocker arm 2 has a rocker mechanism 20 with a lower A-frame 21 and an upper A-frame 22. The entire rocker arm 2 can be pivoted or rocked by means of the rocker mechanism 20. The rocker mechanism 20 can also be referred to as a needle feeder mechanism.

[0042] The support strand 3 is attached to a lower area of ​​the main boom 1 and to a free end of the lower A-frame 21.

[0043] In Fig. 1 The assembled crane 10 is shown in a parked position, with the boom equipment laid on the ground and in a horizontal position. The luffing jib 2 is fully folded against the main boom 1. The main boom 1 and the luffing jib 2 are therefore folded together.

[0044] The in Fig. 1 The depicted position of the crane 10 is reached after the crane 10 has been assembled or after the boom equipment has been completely lowered. To achieve this position, the support structure 3 can be extended. This extension can be accomplished by means of one or two hydraulically and / or electrically operated lifting elements within the support structure 3. In this embodiment, the support structure 3 has exactly one lifting element. The crane 10 can have several lifting elements, e.g., two lifting elements arranged in parallel. In this embodiment, the lifting element is a hydraulic cylinder. Fig. 1 In the depicted position of the crane 10 or the boom equipment, the required extension of the support chain 3 is at its maximum. The lifting element is fully extended.

[0045] In the Fig. 1 In the depicted parking position of the crane 10, the support chain 3 can be relieved of load and the lifting element 30 placed on the main boom 1. The lower A-frame 21 is secured with a chain.

[0046] The lifting element 30 can also be decoupled from the adapter and retracted. The adapter can be secured.

[0047] In Fig. 2 The crane 10 is shown with its boom erected, with the main boom 1 and the luffing jib 2 in a vertical position or vertically aligned and folded. The in Fig. 2 The position shown is reached after the boom equipment is erected or before the boom equipment is lowered into its horizontal parking position after work is completed. In the Fig. 2 In the depicted position of the crane 10 or the boom equipment, the required extension of the support chain 3 is at its maximum. The lifting element(s) are fully extended.

[0048] Depending on the boom configuration, the A-frames 21 and 22 assume an angle of α 1.

[0049] The required length of the lifting element 30 varies depending on the boom configuration.

[0050] The main boom 1 assumes an angle between 88° and 90° relative to the ground in its vertical position.

[0051] In Fig. 2 Detail I is circled, which is in Fig. 3 shown enlarged.

[0052] In Fig. 3 The lifting element 30 of the support structure 3 is shown in an extended position, with the piston rod 32 of the lifting element 30 fully extended from the housing 31 of the lifting element 30. The lifting element 30 is a hydraulic cylinder. The housing 31 is attached to the main boom 1, and the piston rod 32 is attached via an adapter of the piston rod 32 to a main strand of the support structure 3 leading to the luffing boom 2, e.g., one or more steel cables, steel support rods, and / or CFRP support rods.

[0053] By means of the lifting element 30 integrated into the support structure 3, the support structure 3 is shortened to its working length, whereby the luffing boom 2 is pivoted relative to the main boom 1 until the luffing boom 2 assumes an initial opening angle of α 3 relative to the main boom 1. The luffing boom 2 is then at α 3 and is ready for further pivoting, as shown by Fig. 4 The angle α 1 between the A-blocks 21 and 22 does not change.

[0054] In Fig. 4 The crane is shown in a starting position for the further swinging out of the luffing jib 2.

[0055] In Fig. 4 Detail II is circled, which is in Fig. 5 shown enlarged.

[0056] In Fig. 5 The lifting element 30 of the retaining string 3 is shown in a retracted position, with the piston rod 32 of the lifting element 30 being fully retracted into the housing 31 of the lifting element 30.

[0057] In this position of the lifting element 30, the retaining cable 3 has reached its working length. The lifting element 30 is fully retracted. In its retracted position, the lifting element 30 can be locked by means of a locking device. The required extension or shortening of the retaining cable 3 results from the vertical position of the rocker arm 2 up to the initial opening angle of α 3 = 30°.

[0058] The luffing boom 2 continues to swing out with its luffing mechanism 20 as before. As the luffing boom 2 swings out further, the angle α1 between the A-frames 21 and 22 decreases to a maximum of α2. As the luffing boom 2 retracts, the angle α2 between the A-frames 21 and 22 increases to a maximum of α1. The angle between the lower A-frame 21 and the main boom 1 remains unchanged.

[0059] In Fig. 6 The maximum extended rocker arm 2 with the angle α 2 between the A-frames21 and 22 is shown.

[0060] Fig. 6 Figure 1 shows crane 10 in working position, with the luffing jib 2 shown here at its maximum angle, the angle between the A-frames 21 and 22 being α 2. The entire erection process is complete and crane 10 is ready for operation.

[0061] In the Fig. 6 In the position shown, the retaining strand 3 has its working length, which is fixed by its locking mechanism. The lifting element 30 is fully retracted and locked.

[0062] The sequence of Fig. 1 bis 6 Figure 1 shows an erection process of the boom equipment, and the sequence of Figures 6 to 1 shows a lowering process of the boom equipment.

[0063] In Fig. 7 The locking means by which the lifting element 30 can be locked in its retracted position are shown in the form of two locking tabs 33 arranged on the housing 31 of the lifting element 30, which in this example are screwed on. The locking tabs 33 can also be welded on. The locking tabs 33 are attached to an end of the housing 31 that points towards the main strand of the retaining strand 3.

[0064] The piston rod 32 is in Fig. 7 fully retracted and has an adapter with a coupling tab 34 with which the piston rod 32 is connected to the main strand of the retaining strand 30 leading to the rocker arm 2.

[0065] Each of the locking tabs 33 and the coupling tab 34 has an opening. When these openings are aligned, i.e., when the piston rod 32 is fully retracted into the housing 31, a locking bolt 35 can be guided through these openings, as shown in the figure. Fig. 8 emerges.

[0066] In other words, they show Fig. 7 and 8 The connection of the main strand of the retaining strand 3 with the lifting element 30 in its locked position. At least one locking tab 33 is attached to the housing 31 of the lifting element 30, which enables the piston rod 32 to be locked against unintentional extension.

[0067] In Fig. 8 Further tabs 36 of the adapter between the main strand of the retaining strand 3 and the lifting element 30 are shown. The connection of these tabs 36 is secured with a cotter pin 37.

[0068] The position of the locking bolt 35 is monitored by means of monitoring devices. These devices allow determination of whether the locking mechanism is open or closed, and whether the locking bolt 35 passes through all openings or not.

[0069] If the piston rod 31 of the lifting element 30 is not locked with the locking bolt 35, i.e., in the open position, the crane lifting operation is not enabled. The crane remains in the "assembly" operating state until confirmation of correct locking is received. In the "crane operation" or "crane lifting operation" operating state, the locking bolt 35 cannot be unlocked. To unlock it, the crane must first return to the "assembly" operating state. Monitoring can be carried out using an electric rocker switch and / or proximity sensors. This device ensures that the length of the retaining chain 3 cannot be changed during crane lifting operation.

Claims

1. Crane, in particular mobile crane, with a main boom and a luffing jib pivotally mounted on the main boom, wherein a support string runs between the main boom and the luffing jib, characterized by the fact that The retaining cord has a lifting element that can be changed in length and can therefore be altered in length.

2. Crane according to claim 1, characterized by the fact that the lifting element is a hydraulic lifting element, in particular a hydraulic cylinder, or an electric lifting element, in particular a linear actuator.

3. Crane according to claim 1 or 2, characterized by the fact that the support string can be extended in such a way that the luffing boom can be pivoted relative to the main boom so that the luffing boom rests against the main boom.

4. Crane according to one of the preceding claims, characterized by the fact thatthe support string is attached at one end to a lower or upper area of ​​the main boom in a vertical position, with the lifting element being arranged at this end of the support string.

5. Crane according to one of the preceding claims, characterized by the fact that the retaining strand has locking means designed to lock the lifting element, in particular in a retracted position of the lifting element, especially in such a way that the lifting element cannot be extended.

6. Crane according to claim 5, characterized by the fact that The locking means comprise or represent a hydraulic element, in particular a hydraulic cylinder, or an electrically operated element, in particular a linear actuator.

7. Crane according to one of the preceding claims, characterized by the fact that that the lifting element has a housing and a piston rod that can be extended from the housing and retracted into the housing.

8. Crane according to claims 5 and 7 or 6 and 7, characterized by the fact that The housing is provided with one or more locking tabs, each with an opening, wherein the piston rod has an opening, and wherein a locking element, in particular a locking bolt, is provided, and wherein the locking element can be guided through the opening of the locking tab or the openings of the locking tabs and the opening of the piston rod when the openings are aligned, in order to lock the lifting element in a retracted position, and wherein the locking means comprise the locking tab or locking tabs and the locking element.

9. Crane according to one of claims 5 to 8, characterized by the fact that The locking means include monitoring means, in particular an electromechanical switch or a proximity switch, by means of which the position of the locking means, in particular the locking element, can be determined.

10. Method for operating a crane, in particular according to one of claims 1 to 9, comprising the steps of: - shortening the holding string by shortening the lifting element, wherein the luffing jib is pivoted out by an initial opening angle relative to the main jib; - locking the lifting element.

11. Method according to claim 10, characterized by the fact that First, the main boom and the attached luffing boom are raised from a horizontal position to a vertical position.

12. Method according to claim 10 or 11, characterized by the fact thatThe crane is brought into a parking position by first bringing the crane to a state in which the main boom is in a vertical position and the luffing jib is pivoted by the initial opening angle relative to the main boom, followed by unlocking the lifting element(s) and / or extending the holding string by extending the lifting element(s), pivoting the luffing jib by the initial opening angle relative to the main boom so that the luffing jib rests against the main boom.

13. Method according to claim 12, characterized by the fact that Subsequently, the main boom and the attached rocker boom are lowered from the vertical position into a horizontal position.

14. Method for retrofitting a crane with a main boom and a luffing jib pivotally mounted on the main boom, wherein a retaining strand runs between the main boom and the luffing jib, characterized by the fact that one or more lifting elements of variable length are incorporated into the support structure, so that the crane becomes a crane according to one of claims 1 to 9.

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