Crane, particularly mobile crane

Abstract

To provide a crane, particularly a mobile crane, equipped with a boom that can be raised and lowered around a horizontal luffing axis, and a lifting mechanism having a cable winch and a lifting cable attached to the cable winch so as to be capable of being wound and unwound.SOLUTION: A crane includes a cable hold-down device 20 disposed between a cable winch 14 and a boom 12 and configured to limit the maximum distance of a lifting cable 16 from the luffing axis, and / or a lifting cable retention device disposed on the boom 12 and capable of temporarily securing the lifting cable 16 to the boom 12 in the parking position. The lifting cable retention device is configured to disconnect the lifting cable 16 from the boom 12 when a predetermined lifting cable force is exceeded.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a crane, in particular a mobile crane according to the preamble of claim 1. [Background technology]

[0002] A crane comprises a boom and a lifting cable that is guided on the boom and housed in a winch. Both fixed and mobile cranes can be fitted with a swivel boom that can be raised and lowered about a horizontal luffing axis.

[0003] In certain situations, it is necessary to temporarily or permanently attach a lifting cable to a boom. This is the case, for example, with small mobile cranes suitable for use in buildings. Here, the working height of the boom, which is usually configured as a telescopic boom, is limited by the ceiling. However, to maintain a sufficient working area, it is common to use a special head traverse (traversing device). This can directly support the load, so a lifting cable with a load hook is not required. In this case, movement to lift the load is performed, for example, by raising the boom and therefore the head traverse and the lifting device or load lifting hook.

[0004] Due to the space requirements of the head traverse, the load hook must be removed from the end of the boom. For this reason, the lifting cable is temporarily stowed or secured to the boom when the traverse is in operation. The required removal of the lifting cable is complex and must be carried out by at least two people. The first person controls the crane and reels the lifting cable with the winch. The second person maintains tension on the lifting cable and ensures adequate reeling quality. This is particularly important when re-laying the lifting cable.

[0005] To minimize the reeling distance of the lifting cable, the end of the lifting cable is secured near the free end of the telescopic boom connection. This provides two anchoring points for the lifting cable. The first anchoring point is where the lifting cable joins the boom near the free end of the connection. The second anchoring point is where the lifting cable is reeled onto the winch drum.

[0006] The first point is at the connection point, so it moves about the luffing axis when the boom is raised or lowered. The second point is located on the upper carriage, so its position does not change when the telescopic boom is hoisted. Therefore, the distance between the two fixed points, and therefore the cable length, changes as the boom hoist moves.

[0007] This is illustrated in Figures 1 and 2, which show an example of a mobile crane. The mobile crane has a mobile lower truck and an upper truck pivotally mounted to the lower truck about a vertical axis. A telescoping boom 12 is pivotally mounted on the upper truck for tilting about a horizontal axis. A cable winch 14 (not shown) is located behind the upper truck in the ballast area of ​​the upper truck and supports a lifting cable 16 that runs along the top or back surface of the boom 12. Figure 1 shows the mobile crane with the boom 12 in an erected position. The solid double arrow indicates the distance or cable length L1 between the points (the attachment point to the boom 12 and the entry point of the winch 14) when the free end of the lifting cable 16 is attached to the free end of the swing section. Figure 2 shows the mobile crane with the boom 12 in a lowered (prone) position. Here, the distance between the fixing points or the cable length L2 is longer than the cable length L1 when the boom 12 is in an upright position (ie, L2>L1). Summary of the Invention [Problem to be solved by the invention]

[0008] For this reason, it is inappropriate to rigidly connect the lifting cable to the boom. Unintentional tension on the lifting cable can cause serious damage. Furthermore, the change in cable length from L1 to L2 when the boom is lowered is typically very large. With the boom in a steeply inclined position, the lifting cable sags and hangs over the side of the boom. This usually requires the crane operator to re-tension the winch or lifting cable. If the cable is taut with the boom raised, the lifting cable must be loosened or released by performing the reverse operation when lowering the boom. In this case, the crane operator may forget to release or rewind the lifting cable properly, which could result in damage to the lifting mechanism or other parts of the crane.

[0009] It is therefore an object of the present invention to avoid the risk of improper operation or damage to the lifting mechanism when attaching a lifting cable to the boom of such a crane. [Means for solving the problem]

[0010] According to the invention, this problem is solved by a crane having the features of claim 1. Advantageous embodiments of the invention are evident from the dependent claims and the following description.

[0011] The invention therefore proposes a crane with a boom that can be raised and lowered about a horizontal luffing axis and with a lifting mechanism. The lifting mechanism comprises a winch and a lifting cable that can be wound and unwound from the winch. The free end of the lifting cable can be provided with a connection means, such as a cable lock, for attaching a load hook, which cable lock is also suitable for temporarily attaching the lifting cable to the boom (e.g. for traversing operations as described above). The crane can be a fixed crane, although mobile cranes are particularly envisaged.

[0012] According to the present invention, in order to solve the above problem, the crane can be provided with a cable hold-down device arranged between the winch and the boom, which cable hold-down device is configured to limit the maximum distance of the lifting cable from the luffing axis and therefore in particular from the swing part of the boom. The term "cable hold-down device" should be interpreted broadly and refers to any device used to limit the maximum distance of the lifting cable in particular from the luffing axis.

[0013] By being located between the boom and the winch, or in the case of a mobile crane, especially at the rear of the upper carriage behind the boom, the lifting cable is guided so that it is necessarily close to the boom at steep boom positions. This avoids the situation shown in Figure 1 and reduces the difference in cable lengths L1 and L2 between the boom-lowered and boom-raised positions. This eliminates the need to re-tension the lifting cable when raising the boom. Furthermore, any change in the exit point of the lifting cable from the winch is largely prevented.

[0014] Alternatively or additionally, to solve the above-mentioned problems, the crane according to the present invention can be provided with a lifting cable retention device mounted on the boom, which can temporarily secure the lifting cable to the boom in a parking position (standby position). The lifting cable retention device is configured to automatically release the connection between the lifting cable and the boom if a predetermined lifting cable force is exceeded. This prevents damage to the lifting mechanism or the boom if the crane operator accidentally tensions the cable in a steep position. If the tension in the lifting cable becomes too great, the lifting cable and the boom are properly disconnected, and the lifting cable is released from its anchorage before damage occurs. This allows for a longer cable length and allows the boom to be lowered safely.

[0015] Preferably, the lifting cable is held to the boom by a lifting cable retention device and / or other retention device so that when disconnected the lifting cable does not fall off the boom (which could cause further damage and risk to personnel), but has greater freedom of movement for the boom.

[0016] In the crane according to the invention, it is preferred to use both means (cable hold-down device and lifting cable retention device) together.

[0017] In a possible embodiment, the cable hold-down device comprises a bracket (retaining part) and a guide rod detachably mounted within the bracket. The guide rod contacts the lifting cable, thereby limiting the distance between the lifting cable and the luffing shaft or the boom. Because the guide rod is detachably mounted and can be removed, the cable hold-down device can only be used in certain situations, particularly during parking operations where the lifting cable is temporarily fixed to the boom. During normal operation, particularly when the lifting cable is guided by a roller head located at the tip of the boom and is normally used to move a load, it is preferable not to use the cable hold-down device, which therefore does not need to be configured to withstand the large loads that occur when lifting a load during normal operation.

[0018] During normal operation, the guide rod can be removed and fixed in the parking position on a parking bracket (second bracket). The parking bracket can be positioned axially next to the bracket, so that the guide rod only needs to move axially. Alternatively, the guide rod can remain attached to the bracket during normal operation, with the lifting cable passing above it instead of below. The guide rod is preferably positioned parallel to the luffing axis.

[0019] The guide rod may be removably attached to the bracket via a locking mechanism, which may include a latch bolt and / or at least one safety pin to allow for quick and easy attachment and removal.

[0020] In another possible embodiment, the cable hold-down device has a guide element configured to prevent contact between the boom and the lifting cable in the flat boom position. The guide element may be a conventional guide roller (also called a deflector roller), which may be mounted on the bracket or on a separate bracket. The guide element is configured to direct the lifting cable away from the boom (especially the pivoting section of a telescoping boom) in the flat boom position, preventing damage due to contact and friction.

[0021] In other possible embodiments, the cable hold down device is not connected to the boom, in particular the cable hold down device is rigidly connected to the structure of the crane (in particular the steel structure of the upper truck) so as to move relative to the cable hold down device during boom hoisting.

[0022] Alternatively or additionally, the cable hold-down device can be located in (near) the area of ​​the luffing axis of the boom. When the cable hold-down device is located near the luffing axis, the difference in cable lengths (the difference between L1 and L2) is minimized.

[0023] In another possible embodiment, the lifting cable has at its free end a connecting means, in particular a cable lock, by which the lifting cable can be detachably connected to the lifting cable holding device, which can also be used at the same time to attach a load lifting device (e.g. a hook block) to the lifting cable.

[0024] In another possible embodiment, the lifting cable retention device has a predetermined break point configured to break when a predetermined lifting cable force is exceeded, thereby releasing the connection between the boom and the lifting cable.

[0025] Alternatively, the lifting cable retention device may include a release mechanism configured to release the direct or indirect connection between the lifting cable and the boom when a predetermined lifting cable force is exceeded. Unlike an irreversible release of the connection in the event of a predetermined break, in this case the release of the connection can be reversed or "repaired." This can be accomplished by any mechanical mechanism, such as releasing the lifting cable or a guide connected to the lifting cable from a spring-loaded bracket connected to the boom.

[0026] In another possible embodiment, the lifting cable retention device has at least one retention means by which the lifting cable can be connected to the boom. The retention means is preferably a cable (retention cable) or a chain, or a combination of a cable and a chain. The retention means is connectable to the boom by a first connection element and to the lifting cable (directly or indirectly) by a second connection element. The first and / or second connection element may be, for example, a carabiner, a shackle, a plate, a bolt, or a screw, or a combination thereof.

[0027] In other possible embodiments, the predetermined break is formed in the holding means (e.g. in the case of a chain, the holding cable or chain) or, instead, a release mechanism is arranged in the holding means. The predetermined break or release mechanism may be arranged in the first connecting element or in the second connecting element.

[0028] In another possible embodiment, the lifting cable retention device comprises a traverse (cross member, cross beam) and two retention means connected to the traverse. The retention means are preferably movably connected to the traverse, in particular via the aforementioned second connection element. The traverse comprises a connection means to which the lifting cable can be detachably connected. In the simplest example, the connection means can be a bolt receptacle for receiving a carabiner, cable lock, bolt, or the like. The lifting cable is attached to the boom by connecting it to the traverse, which is attached to the boom via the retention means. The retention means are specially configured as a cable or chain so that the traverse is movably attached to the boom.

[0029] Preferably, the connecting means are located closer to one end of the traverse than the other end, and this asymmetric or off-center location of the connecting means causes one of the retaining means (particularly the retaining means mounted closer to the connecting means) to be subjected to a greater load than the other retaining means when forces are applied through the lifting cables.

[0030] Therefore, in yet another possible embodiment, a predetermined break or release mechanism is provided at only one of the retaining means and / or at the connection point with the boom or traverse (in particular the aforementioned first or second connection element). If the connection between the lifting cable and the boom breaks at the predetermined break or is released by the release mechanism in an overload situation, no damage or injury will occur, as the lifting cable will remain connected to the boom by the traverse and other retaining means and will be prevented from detaching from the boom. Furthermore, the combined length of the intact retaining means and the traverse, both of which are preferably pivotally mounted, will provide sufficient play in the lifting cable to allow the boom to tilt downwards without tensioning the lifting cable.

[0031] In order to achieve the aforementioned off-center location of the connecting means on the traverse, it is preferred that the predetermined breaking point or release mechanism be located on the retaining means or its connection point which is closer to and subject to greater loads than the connecting means on the traverse.

[0032] In another possible embodiment, the traverse and holding means are configured in such a way that in a released or broken state, the boom can be lowered sufficiently without activating the cable winch and without tensioning the lifting cable, allowing the crane operator to tilt the boom sufficiently downwards and operate the crane to a safe position without taking any further safety precautions after the lifting cable has been disconnected due to an overload.

[0033] In another possible embodiment, one of the holding means has a predetermined break in the first connection element between the holding means and the boom. The first connection element can be connected to the rope structure of the boom preferably by a screw connection, the predetermined break being formed in the screw. When the load on the tension of the lifting cable, and therefore on the screw, exceeds a predetermined value, the screw breaks and the connection between the holding means and the boom is released. The first connection element may be formed as a metal sheet or a connecting plate and / or may include other components such as a carabiner or a shackle.

[0034] In another possible embodiment, the first connection elements have connecting plates that are bent or angled at a specific angle, which allows the length of the traverse to be shorter than the distance between the first connection elements of the holding means, so that the traverse can be placed between or inside second cable holding devices, for example, mounted on the boom. To eliminate this difference in length, the connecting plates can be angled slightly inwards, so that the holding means extend (converge) in the direction of the traverse.

[0035] The bending angle of the connecting plates may preferably be in the range of 135° to 179°, in particular between 150° and 175°, which represents the angle between the angled portions of the plates (flat plates would have a "bending angle" of 180° in this definition).

[0036] In another possible embodiment, the lifting cable retention device is arranged on and / or between a second cable retention device, in particular pivotally mounted on the boom, which is used in a known manner to prevent the lifting cable from coming into contact with the boom during normal operation (in particular when the lifting cable extends to the roller head at the tip of the boom). At least one retention means can be attached to the connection between the second cable retention device and the boom.

[0037] In another possible embodiment, the crane is configured as a mobile crane with a rotatable upper truck. The boom is configured as a telescopic boom having a swivel section and one or more telescopic sections movably mounted therein and is disposed on the upper truck. The lifting cable retainer is disposed on the swivel section of the telescopic boom. Alternatively or additionally, the cable hold-down device can be disposed on the upper truck between the boom and the upper truck ballast. The cable winch can be disposed on the upper truck ballast or on the steel structure of the upper truck.

[0038] Further features, details and advantages of the present invention will become apparent from the following description of the embodiments based on the drawings. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a schematic side view of a conventional mobile crane in a boom-raised state. [Figure 2] FIG. 2 shows the mobile crane shown in FIG. 1 in a prone position. [Figure 3] FIG. 3 is a perspective view of a cable pressing device according to an embodiment of the present invention. [Figure 4] FIG. 4 is a perspective view of a lifting cable retention device according to an embodiment of the present invention. [Figure 5] FIG. 5 is a perspective view of a traverse of the lifting cable retention device. [Figure 6] FIG. 6 is a perspective view of a connection plate of a holding cable of a lifting cable holding device. [Figure 7] FIG. 7 is a perspective view of a first connection element of a holding cable of a lifting cable holding device. DETAILED DESCRIPTION OF THE INVENTION

[0040] 1 and 2 show an example of a mobile crane known in the prior art and which has already been described.

[0041] 3 is a perspective view of one embodiment of a cable hold-down device 20 of the present invention positioned between the boom 12 and the winch 14. The crane 10 of the present invention may be configured as shown in FIGS. 1-2, but is not limited to such a mobile crane. Rather, the cable hold-down device 20 may be used with any crane having a boom 12 that hoists.

[0042] The cable hold-down device 20 is positioned near the luffing axis of the boom 12 and has a bracket 22 rigidly connected to the upper truck 11 or the steel structure of the upper truck, and a guide rod 24 detachably attached to the bracket 22. In the illustrated example, the guide rod is attached to receivers on two sides of the bracket 22 and can be locked and secured by one or more locking bolts 26 and, if necessary, one or more split pins.

[0043] FIG. 3 also shows a portion of the cable winch 14 and the lifting cable 16. During parking (i.e., when the lifting cable 16 is temporarily secured to the boom, for example, via a cable lock 17 attached to the end of the lifting cable 16), the cable is routed between the upper truck 11 and the guide rod 24 through a cable hold-down device 20, allowing the boom to be positioned closer to the luffing axis than in FIG. 1, even at steeper boom positions. As a result, the difference between cable lengths L1 and L2 (see FIGS. 1 and 2) is reduced, eliminating the need to reel in the lifting cable 16 during the parking erection operation. Conversely, this means that the risk of the lifting cable 16 straining and breaking or damaging other crane components when lowering the boom 12 is eliminated or at least reduced.

[0044] The guide rod 24 can be removed to allow the lifting cable 16 to be moved out of the cable holding device 20 during normal operation (especially when the lifting cable 16 is guided by a roller head located at the tip of the boom).

[0045] In normal operation, the guide rod 24 can be held in a parked position where it does not come into contact with the lifting cables 16. In the embodiment of Figure 3, the second bracket 23 is offset from the bracket 22 in the axial direction of the guide rod 24, so that the guide rod 24 only needs to move axially. Alternatively, the second bracket for the guide rod 24 can be located anywhere on the crane 10.

[0046] For a mobile crane with a telescoping boom 12, during normal operation, the lifting cable 16 extends directly from the cable winch 14 through the base (connection) of the boom 12 to the roller head. The guide rod 24 of the cable hold-down device 20 may be in a parking position on the second bracket 23. When using the mobile crane 10, for example, for a head traverse, the crane operator lowers the boom 12. The cable 16 then extends from the cable winch 14 parallel to and adjacent to the base toward the roller head. The crane operator then releases the guide rod 24 from the second bracket 23 and tucks or places it over the lifting cable 16, securing or locking the guide rod 24 within the bracket 22.

[0047] Figure 4 shows an embodiment of the lifting cable retention system of the present invention attached to the boom 12 of a crane 10. The crane may be the mobile crane shown in Figures 1-2 or any other crane. Figure 4 shows only the connection portion of the boom 12, which in this case is configured as a telescoping boom. The lifting cable retention system may also be used with a lattice boom or any other boom 30.

[0048] The lifting cable retention device 30 comprises an elongated traverse 34 attached to the steel structure or swivel (connection) of the boom 12 via two retention means 32. The retention means 32 can be a steel cable, i.e., retention cable 12, connected to the traverse 34 via a carabiner 42 (second connection element). To this end, the traverse 34 can be provided with a receiver 37 at its end (see FIG. 5). Instead of the carabiner 42, any other connection element (e.g., a shackle) may also be used. The traverse 34 receives the retention means 34 symmetrically, in particular in the lateral receivers 37.

[0049] The holding means 32 is movably connected to the boom 12 by a first connecting element 41. Figure 7 shows an enlarged view of the first connecting element 41. This first connecting element may comprise a connecting plate 44 and a carabiner 49 connected to the steel structure of the boom 12 by screws 48.

[0050] An embodiment of the connecting plate 44 is shown in isolation in Figure 6. This embodiment has at a first end a first receiving portion 45 for a carabiner 49, which movably connects the connecting plate 44 to the holding means 32. Instead of the carabiner 49, any other connecting element (e.g. a shackle) can be used. The connecting plate 44 comprises a second end with a second receiving portion 46 for receiving a screw 48. This screw can be secured with a nut.

[0051] The boom 12 may be provided with a second cable holding down device 18, which is preferably pivotally mounted on the boom 12 or on the steel structure of the connection. The first connection elements 41 of the lifting cable holding device 30 may be connected to the boom 12 in the connection area of ​​the second cable holding down device. In this case, the traverses 34 may be shorter than the distance between the first connection elements 41, so that the traverses 34 can be located between the lateral legs of the second cable holding down device 18. For this purpose, the connection plates 44 may be angled between their first and second ends (see FIG. 6), so that the holding means 32 do not extend parallel to each other but are arranged close to each other.

[0052] The traverse 34 has connection means 36, which in the example of Figure 5 can be formed as a receptacle or bolt hole, to which can be fastened, for example, a cable lock 17 attached to the end of the lifting cable 16. Thus, in the parking position, the lifting cable 16 can be connected to the traverse 34 and thus to the boom 12 via the cable lock 17. This connection can be made by bolting. During operation of the crane, the lifting cable 16 can preferably be connected either to a load retention device (e.g. a hook block) or to a roller head, depending on the reeling method.

[0053] When the boom 12 is lowered with the lifting cable 16 tensioned in the parking position, the increased cable length L2 can cause damage to the lifting cable 16, the cable winch 14, and / or the boom 12. To prevent this, in accordance with the present invention, the lifting cable retention device 30 is configured to disconnect the lifting cable 16 from the boom 12 when a predetermined lifting cable force is exceeded.

[0054] One way to achieve this is for the retention means itself to be specially constructed so that it can be reversibly "self-sacrificed."

[0055] Alternatively, a predetermined breakage portion that breaks when the cable is lowered can be provided at an appropriate position on the cable holding device 30. In the embodiment shown in Fig. 4, the predetermined breakage portion is realized by one of the screws 48 of the first connecting element 41. For this purpose, the screw 48 is formed sufficiently small.

[0056] For example, a small threaded connection consisting of a screw 48, a nut, and a washer can be used. The screw 48 is subject to withstand shear forces during normal operation. However, if an error occurs (re-tensioning the lifting cable 16 and subsequently lowering the boom 12 without releasing the lifting cable 16), tension will increase in the lifting cable 16 and the lifting cable retention device. The weakest connection in this force path is the screw 48, which is subject to the shear forces. The screw 48 will shear off at a given force. All other connections are protected and will not be damaged.

[0057] Preferably, the predetermined break is provided in only one of the retaining means 32. If the corresponding screw 48 breaks, the lifting cable 16 will not fall but will remain retained to the boom 12 via the traverse 34 and the other retaining means 32, which is still intact and connected to the boom 12. The only part that will fall is the small broken screw 48, with no risk of damage or injury.

[0058] The connection means 36 of the traverse 34 is preferably positioned off-center, i.e., near one of the receiving portions 37 and away from the opposite receiving portion 37, as shown in FIG. 5 . This results in an asymmetrical force flow, with the break point (screw 48) of the holding means 32 located closer to the connection means 36 experiencing a significantly greater load than the opposite screw 48. After the break point breaks, tension is released and the traverse 34 can pivot around the other receiving portion 37 or the corresponding second connection element 42. This range of rotation provides sufficient freedom of movement for operation, allowing the boom 12 to be lowered again sufficiently. Furthermore, the crane operator receives safety feedback regarding the use of the predetermined break point and can release the lifting cable 16 if necessary.

[0059] It is of course possible to use other breakaway points instead of the screws 48, for example arranged on the holding means 32 or on the holding cable, so that after breaking all parts remain connected to the crane 10. It is also possible to provide a breakaway point on the second connecting element 42. [Explanation of symbols]

[0060] 10 Crane 11 Upper carriage 12. Boom 14 winch 16 Lifting Cable 17 Cable Lock 18 Second cable holding device 20 Cable holding device 22 Bracket 23 Second Bracket 24 Guide rod 26 Rock Bolt 28 Guide Elements 30 Lifting cable retention device 32 Holding means 34 Traverse 36 Connection Methods 37 Connection Methods 41 first connecting element 42 Second connecting element 44 Connecting plate 45 First receiving part 46 First receiving part 47 bending angle 48 screws 49 Carabiner

Claims

1. A crane (10), particularly a mobile crane, comprising a boom (12) that can be raised and lowered about a horizontal luffing axis, a lifting mechanism having a cable winch (14) and a lifting cable (16) that is attached to the cable winch (14) so ​​that it can be wound and unwound, a cable hold-down device (20) disposed between the cable winch (14) and the boom (12) and configured to limit the maximum distance of the lifting cable (16) from the luffing axis, and / or a lifting cable retention device (30) disposed on the boom (12) and capable of temporarily fixing the lifting cable (16) to the boom (16) in a parking position, the lifting cable retention device (30) configured to release the connection between the lifting cable (16) and the boom (12) when a predetermined lifting cable force is exceeded. A crane (10) characterized in that:

2. The crane (10) of claim 1, The cable holding device (20) comprises a bracket (22) and a guide rod (24) removably mounted within the bracket (22), the lifting cable (16) being guided outside the cable holding device (20) during normal operation, particularly when the front guide rod is removed, and within the cable holding device (20) during parking operation when the guide rod is attached, the guide rod (24) being preferably parallel to the luffing axis of the crane (10).

3. A crane (10) according to claim 1 or 2, The crane (10) has a cable hold-down device (20) having guide elements (28), in particular guide rollers, configured to prevent contact between the boom (12) and the lifting cable (16) in a flat boom position.

4. A crane (10) according to any one of claims 1 to 3, A crane (10) in which the cable hold-down device (20) is not connected to the boom (12) and / or is located in the area of ​​the luffing axis.

5. A crane (10) according to any one of claims 1 to 4, The lifting cable (16) of the crane (10) has at its free end a connecting means, in particular a cable lock (17), by which the lifting cable (16) can be detachably connected to the lifting cable holding device (30).

6. A crane (10) according to any one of claims 1 to 5, The lifting cable retention device (30) has a predetermined breakaway portion configured to break when a predetermined lifting cable force is exceeded, or the lifting cable retention device (30) includes a release mechanism configured to directly or indirectly disconnect the lifting cable (16) from the boom (12) when a predetermined lifting cable force is exceeded.

7. A crane (10) according to any one of claims 1 to 6, The lifting cable holding device (30) has at least one holding means (32) capable of connecting the lifting cable (16) to the boom (12), the holding means (32) being connected to the boom (12) by a first connecting element (41) and to the lifting cable (16) by a second connecting element (42), the holding means (32) being preferably configured as a cable or chain.

8. A crane (10) according to claim 6 or 7, The breaking portion or the release mechanism is formed or arranged on the holding means (32) and / or the first connecting element (41) and / or the second connecting element (42).

9. A crane (10) according to claim 7 or 8, The lifting cable holding device (30) comprises a traverse (34) and two holding means (32) particularly movably connected to the traverse (34), the traverse (34) comprising a connection means (36) to which the lifting cable (16) can be detachably connected, the connection means (36) being preferably arranged near one end side of the traverse and away from the other end side of the crane (10).

10. A crane (10) according to claim 9, A crane (10) in which only one of the retaining means (32) and / or its connection point with the boom (12) or the traverse (34) has a predetermined breaking point or the release mechanism so that when the connection between the lifting cable (16) and the boom (12) is released, the lifting cable (16) continues to be held to the boom (12) via the traverse (34) and the other retaining means (32), and the predetermined breaking point or the release mechanism is preferably located on the retaining means (32) or its connection point which is located closer to the connection means (36) of the traverse.

11. A crane (10) according to claim 10, The crane (10) is configured such that, in a released or broken state, the traverse (34) and holding means (32) allow the boom (12) to be fully tilted without operating the cable winch (14) and without applying tension to the lifting cable (16).

12. A crane (10) according to any one of claims 9 to 11, A crane (10) in which one of the holding means (32) has a predetermined break in a first connection element (41) between the holding means (32) and the boom (12), the first connection element (41) being preferably connected to the boom (12) by a bolt (48), the predetermined break being formed in the bolt (48).

13. A crane (10) according to any one of claims 7 to 12, At least one holding means (32) is connected to the boom (12) via the first connecting element (41), the first connecting element (41) comprising a bent connecting plate (44), the bending angle (47) of which is preferably in the range of 135° to 179°, in particular in the range of 150° to 175°.

14. A crane (10) according to any one of claims 1 to 13, A crane (10) in which the lifting cable retention device (30) is arranged on and / or between a second cable retention device (18) pivotally mounted in particular on the boom (12).

15. A crane (10) according to any one of claims 1 to 14, A mobile crane configured with a rotatable upper bogie (11), wherein the boom (12) is a telescopic boom and is arranged on the upper bogie (11), the lifting cable holding device (30) is arranged at the connection of the telescopic boom (12), and / or the cable holding device (20) is arranged on the upper bogie (11) between the boom (12) and the ballast of the upper bogie.

Images