Crane and method for assembling and disassembling a crane

Abstract

To provide a crane which can improve workability when a strut in a lodged state is raised, and a crane assembly / disassembly method.SOLUTION: A crane has: a boom 24 mounted so as to undulate on a crane body; a jib 25 mounted so as to undulate at the tip of the boom 24; a strut 27 mounted so as to undulate at the tip of the boom 24 or the base end of the jib 25; a winch provided on the crane body or the boom; a winding rope 32 which is wound around the winch and is connected so as to be attached / detached to / from the strut 27; and a support leg 2 which is mounted on a surface on the strut 27 side of the jib 25 or a surface on the jib 25 side of the strut 27. In a state where the boom 24 and the jib 25 are lodged on the ground surface, and the strut 27 is lodged on the jib 25 through the support leg 2, a height in a part to which the winding rope 32 is connected in the strut 27 is higher than the base end of the strut 27.SELECTED DRAWING: Figure 6

Description

[TECHNICAL FIELD]

[0001] The present invention relates to a crane and a method for assembling and disassembling a crane. [BACKGROUND ART]

[0002] Patent Document 1 discloses an assembling method in which when assembling a crane, a main hoisting rope (hoisting rope) is connected to a lifting lug of a jib mast (strut), and the hoisting rope is wound up by a winch to erect the strut in a laid-down state. In Patent Document 1, the direction of pulling the lifting lug with the hoisting rope is changed by a guide sheave provided at the tip of a boom, so that the traction force of the hoisting rope effectively acts as a moment for rotating the strut. According to the assembling method of Patent Document 1, it is not necessary to prepare an auxiliary crane separate from the crane for erecting the strut. [PRIOR ART DOCUMENT] [PATENT DOCUMENT]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2011-190084 [SUMMARY OF THE INVENTION] [PROBLEM TO BE SOLVED BY THE INVENTION]

[0004] Incidentally, since the hoisting rope is wound in rows according to the drum width of the winch, the hoisting rope is angled with respect to the tip of the boom. Therefore, in Patent Document 1, it is necessary to align the groove of the guide sheave and the hoisting rope in the width direction. However, this work is time-consuming when performed at a high place on the boom under poor scaffolding conditions.

[0005] An object of the present invention is to provide a crane and a method for assembling and disassembling a crane, which can improve workability when erecting a strut in a laid-down state and workability when laying down a strut in an erected state. [MEANS FOR SOLVING THE PROBLEM]

[0006] The present invention comprises a crane body, a boom mounted to the crane body in a luffable manner, a jib mounted to the tip of the boom in a luffable manner, a strut mounted to the tip of the boom or the base of the jib in a luffable manner, a winch provided on the crane body or the boom, a rope wound around the winch and detachably connected to the strut, and a support leg attached to the strut-side surface of the jib or the jib-side surface of the strut, wherein, when the boom and jib are laid down on the ground, and the strut is laid down on the jib via the support leg, the height of the portion of the strut to which the rope is connected is higher than the base of the strut. [Effects of the Invention]

[0007] According to the present invention, when the boom and jib are collapsed on the ground and the strut is collapsed onto the jib via the support legs, the height of the part of the strut to which the rope is connected is higher than the base end of the strut. Therefore, when the strut is collapsed onto the jib, a moment can be obtained to rotate the strut in the direction of raising it by pulling the rope. This makes it possible to suitably raise the collapsed strut. Furthermore, by paying out the rope, when collapsing the upright strut onto the jib, tension can be constantly applied to the rope while the strut is being collapsed. This makes it possible to suitably raise the upright strut. And, unlike Patent Document 1, there is no need to align the groove of the guide sheave provided at the tip of the boom with the rope in the width direction, so the workability when raising the collapsed strut and the workability when lowering the upright strut can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of a crane, showing the boom in its upright position. [Figure 2] This is a side view of the crane, showing the boom and jib in a reclined position on the ground. [Figure 3] This is a view of the tip of the strut from above. [Figure 4] This is a side view of the boom. [Figure 5] This is a side view of the crane, showing the struts in the lowered position. [Figure 6] This is an enlarged view of the main part A in Figure 5. [Figure 7] A perspective view of the jib and strut. [Figure 8] This is a side view of the support leg, showing the support leg in its operating position. [Figure 9] This is a side view of the support leg, showing the support leg in its retracted position. [Modes for carrying out the invention]

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0010] (Crane configuration) As shown in Figure 1, a side view of the crane 1 of this embodiment, the crane 1 has a configuration in which an upper slewing body 22 is rotatably mounted on a crawler-type lower traveling body 21. The lower traveling body 21 and the upper slewing body 22 constitute the crane body. The crane 1 may be a mobile crane using means of movement other than crawlers (e.g., wheels), or it may be a fixed crane without means of movement. Furthermore, the present invention can also be applied to tower cranes and luffing cranes.

[0011] The upper slewing body 22 includes a cab 23, a boom 24, a jib 25, a gantry 26, a strut 27, a lower spreader 28, a hook winch 43, a boom luffing winch 45, a counterweight 29, a jib backstop device 47, and a strut backstop device 48.

[0012] The operator's cab 23 is provided at a front portion of the upper revolving superstructure 22. The boom 24 is connected (attached) to the front portion of the upper revolving superstructure 22 so as to be capable of being raised and lowered relative to the upper revolving superstructure 22. The boom 24 is composed of a lower boom 24a, one or more intermediate booms 24b, and an upper boom 24c. One end of a boom guy line 39 is connected to a distal end of the boom 24. FIG. 1 illustrates a state in which the boom 24 is erected.

[0013] The jib 25 is connected (attached) to a distal end portion of the boom 24 so as to be capable of being raised and lowered relative to the boom 24. The jib 25 is composed of a lower jib 25a, one or more intermediate jibs 25b, and an upper jib 25c. A jib point sheave 31 is provided at a distal end of the jib 25. A hook device (not illustrated) is suspended from the jib point sheave 31 via a hoisting rope 32.

[0014] The gantry 26 is attached to a rear portion of the upper revolving superstructure 22. Note that a configuration including a mast instead of the gantry 26 is also acceptable. The strut 27 is connected (attached) to a base end portion (lower jib 25a) of the jib 25 so as to be capable of being raised and lowered relative to the jib 25. Note that the strut 27 may be attached to a distal end portion (upper boom 24c) of the boom 24. A distal end of the strut 27 and the distal end of the jib 25 are connected by a jib guy line 34. Further, the distal end of the strut 27 and a connecting portion 51 provided on the boom 24 are connected by a strut guy line 46. The strut guy line 46 is attachable to and detachable from the connecting portion 51.

[0015] A sheave 52 is provided at a central portion of the strut 27. The hoisting rope 32 is wound around this sheave 52.

[0016] A lower spreader 28 is attached to an upper end of the gantry 26. A boom hoisting rope 41 is stretched between the lower spreader 28 and an upper spreader 40 connected to the other end of the boom guy line 39.

[0017] The hook winch 43 and the boom hoisting winch 45 are each disposed at a central portion of the upper rotating body 22. A hoisting rope (rope) 32 is wound around the hook winch (winch) 43. A boom hoisting rope 41 is wound around the boom hoisting winch 45. Note that the hook winch 43 may be disposed at a base portion (lower boom 24a) of the boom 24. Further, the boom hoisting winch 45 may be disposed at a lower portion of the gantry 26.

[0018] The hook winch 43 winds in or pays out the hoisting rope 32 to hoist or lower the hook device. The boom hoisting winch 45 winds in or pays out the boom hoisting rope 41, thereby causing the boom 24 to hoist and lower about a boom foot pin 42 serving as a fulcrum thereof.

[0019] A counterweight 29 is mounted on a rear portion of the upper rotating body 22.

[0020] A jib backstop device 47 is provided on a lower rear surface side of the jib 25. The jib backstop device 47 is received by a backstop receiver (not shown) provided on the strut 27, thereby restricting rotation of the jib 25 toward a rear side (the strut 27 side).

[0021] A strut backstop device 48 is provided on a lower rear surface side of the strut 27. The strut backstop device 48 is received by a backstop receiver (not shown) provided on the boom 24, thereby restricting rotation of the strut 27 toward a rear side (the boom 24 side).

[0022] In such a configuration, when the crane 1 is disassembled and assembled, as shown in FIG. 2 which is a side view of the crane 1, the boom 24 and the jib 25 are brought into a state of being laid down on the ground.

[0023] As shown in Figure 3, which is a view of the tip of the strut 27 from above, a width-changing link 55 is attached to the tip of the strut 27. In the width direction (vertical direction in the figure) of the boom 24, strut guy lines 46 are connected to both ends of the width-changing link 55.

[0024] A connecting bracket 56 is provided at the center of the width-changing link 55 in the width direction of the boom 24. In this embodiment, when the strut 27 is raised and lowered while the boom 24 and jib 25 are lying on the ground, the hoisting rope 32 is connected to the connecting bracket 56. In this embodiment, the hoisting rope 32 and the connecting bracket 56 are connected via a string-like member 4, which will be described later.

[0025] Furthermore, the portion where the hoisting rope 32 (string-like member 4) is connected to the strut 27 is not limited to the connecting bracket 56, but may be, for example, the central part in the longitudinal direction of the strut 27.

[0026] As shown in Figure 4, a side view of the boom 24, the crane 1 has a string-like member 4. The string-like member 4 is interposed between the strut 27 and the hoisting rope 32, connecting them. Specifically, one end of the string-like member 4 is connected to the strut 27 (connecting bracket 56), and the other end of the string-like member 4 is detachably connected to the hoisting rope 32. In this embodiment, the string-like member 4 is a sling, but it may also be a rope or wire. When the hoisting rope 32 and the strut 27 are not connected via the string-like member 4, the other end of the string-like member 4 is connected to a fastening part (not shown) provided on the strut 27.

[0027] By connecting one end of the string-like member 4 to the strut 27, the other end of the string-like member 4 and the hoisting rope 32 can be connected at a lower position than when the hoisting rope 32 is directly connected to the strut 27. This improves the work efficiency of connecting the strut 27 and the hoisting rope 32.

[0028] In the state shown in Figure 2, when the crane 1 is disassembled, the upright strut 27 is lowered. When the strut 27 is lowered, the hoisting rope 32 is connected to the connecting bracket 56 via the string-like member 4, and the connection between the strut guyline 46 and the connecting part 51 is released. Then, the hoisting rope 32 is paid out from the hook winch 43, causing the strut 27 to be lowered onto the jib 25.

[0029] Figure 5 is a side view of the crane 1, showing the strut 27 in a lowered position. Here, as shown in Figure 6, an enlarged view of the main part A of Figure 5, and in Figure 7, a perspective view of the jib 25 and strut 27, the crane 1 has support legs 2. In this embodiment, the support legs 2 are attached to the side of the jib 25 that faces the strut 27, but they may also be attached to the side of the strut 27 that faces the jib 25.

[0030] As shown in Figure 6, the strut 27 is tilted onto the jib 25 via the support legs 2. At this time, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) becomes higher than the base end (center of rotation) of the strut 27.

[0031] Here, as shown in Figures 6 and 7, the length of the support leg 2 in the opposing direction between the jib 25 and the strut 27 is set so that the sheave 52 provided on the strut 27 does not interfere with the jib 25. As a result, when the strut 27 is in a collapsed state, the sheave 52 does not interfere with the jib 25, thus preventing damage to at least one of the sheave 52 and the jib 25.

[0032] When the strut 27 is lowered, the connection between the hoisting rope 32 and the connecting bracket 56 is released. Specifically, the connection between the hoisting rope 32 and the string-like member 4 is released. Then, the upper jib 25c and the intermediate jib 25b are removed from the jib 25 in that order, and the lower jib 25a and the strut 27 are removed from the boom 24 as a single unit.

[0033] On the other hand, when the crane 1 is assembled, the lower jib 25a and strut 27 are attached to the boom 24 as a single unit. Then, the intermediate jib 25b and upper jib 25c are attached to the lower jib 25a in that order, thereby assembling the jib 25. Then, the hoisting rope 32 and connecting bracket 56 are connected via the string-like member 4, and the hoisting rope 32 is wound up by the hook winch 43, causing the tucked strut 27 to be raised.

[0034] As shown in Figure 6, when the strut 27 is lowered onto the jib 25 via the support legs 2, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is higher than the base end of the strut 27. Therefore, when the strut 27 is lowered onto the jib 25, a moment can be obtained to rotate the strut 27 in the direction of raising it by pulling the hoisting rope 32. This allows the lowered strut 27 to be brought up into a suitable position. Furthermore, by paying out the hoisting rope 32, tension can be constantly applied to the hoisting rope 32 while lowering the strut 27 onto the jib 25. This allows the upright strut 27 to be brought up into a suitable position.

[0035] Furthermore, as shown in Figure 6, when the lower jib 25a and the strut 27 are attached to the boom 24 as a single unit, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is higher than the base end of the strut 27. Therefore, by pulling the hoisting rope 32 connected to the strut 27 via the string-like member 4, a moment can be easily obtained to rotate the strut 27 in the direction of raising it, thus allowing the strut to be raised appropriately.

[0036] As shown in Figure 7, the crane 1 has fastening members 3. The fastening members 3 are for attaching the support legs 2 to the jib 25, and specifically consist of U-bolts and nuts. By using the fastening members 3, welding work is unnecessary, so the support legs 2 can be easily attached to the crane 1 which does not have support legs 2. In addition, since the support legs 2 can be removed, when the support legs 2 are removed from the jib 25 during the disassembly and transport of the crane 1, the transported components (lower jib 25a and struts 27) can be prevented from exceeding the transport height limit.

[0037] As shown in Figures 8 and 9, which are side views of the support leg 2, the support leg 2 can change its orientation between the operational position and the retracted position. As shown in Figure 8, the operational position is an upright position relative to the strut 27 side (rear) of the jib 25. As shown in Figure 9, the retracted position is an upright position along the strut 27 side (rear) of the jib 25.

[0038] The support leg 2 comprises a rigging body 2a and a support portion 2b. The base end of the rigging body 2a and the base end of the support portion 2b are each connected by pins to a bracket 58 provided on the jib 25. As shown in Figure 8, when the support leg 2 is deployed, the tip of the support portion 2b is connected by pins to the side of the upright rigging body 2a. This maintains the upright position of the rigging body 2a. On the other hand, as shown in Figure 9, when the support leg 2 is retracted, the rigging body 2a and the support portion 2b are folded down along the back of the jib 25, and the side of the rigging body 2a and the tip of the support portion 2b are each connected by pins to a bracket 59 provided on the jib 25. This maintains the folded position of the rigging body 2a.

[0039] By positioning the support legs 2 in the operational position, when the strut 27 is tilted over the jib 25 via the support legs 2, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) can be made higher than the base end of the strut 27. On the other hand, by positioning the support legs 2 in the retracted position, when the crane 1 is disassembled and transported, the transported components (lower jib 25a and strut 27) can be prevented from exceeding the transport height limit.

[0040] (modified version) This embodiment may also be applied to cranes 1 equipped with two struts, such as tower cranes and luffing cranes. By providing support legs 2 between the front strut and the jib 25, or between the front strut and the rear strut, the height of the portion to which the string-like member 4 (hoisting rope 32) is connected to the front strut or rear strut can be made higher than the base end (center of rotation) of the front strut or rear strut. This allows the front strut or rear strut to be positioned appropriately.

[0041] (Crane operation) Next, the operation of crane 1 will be explained with reference to the drawing.

[0042] (Crane dismantling) First, we will explain the process of disassembling Crane 1. This section will cover the process from lowering the upright boom 24 and jib 25 to disassembling the jib 25.

[0043] First, as shown in Figure 1, the boom 24 is lowered by extending the boom luffing rope 41. Just before the tip of the jib 25 touches the ground, the jib backstop device 47 is detached from the backstop receiver on the strut 27 and moved along the jib 25. Then, as the boom 24 is lowered further, the jib 25 rotates towards the strut 27, and the tension of the jib guy line 34 is released.

[0044] As the boom 24 is further lowered, the boom 24 and jib 25 will be in a state where they are lying on the ground, as shown in Figure 2. In this state, the strut backstop device 48 is detached from the backstop receiver on the boom 24 and placed along the strut 27. Also, as shown in Figure 3, the hoisting rope 32 is connected to the connecting bracket 56 located in the center of the width-changing link 55 via the string-like member 4. Finally, the support legs 2, which were in the stowed position, are set to the operational position.

[0045] Next, the connection between the connecting section 51 on the boom 24 and the strut guyline 46 is released, and the hoisting rope 32 is unfurled from the hook winch 43 to lower the strut 27. Then, as shown in Figure 5, the strut 27 is lowered onto the jib 25 via the support legs 2.

[0046] As the strut 27 is lowered, as shown in Figure 6, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is always higher than the base end of the strut 27. Therefore, tension can be constantly applied to the hoisting rope 32 while the strut 27 is lowered onto the jib 25 via the support legs 2. This prevents the strut 27 from falling too forcefully, thus preventing damage to the strut 27.

[0047] After lowering the strut 27 onto the jib 25 via the support legs 2, the connection between the string-like member 4 and the hoisting rope 32 is released, and the other end of the string-like member 4 is connected to the fastening part provided on the strut 27. Then, the upper jib 25c and the intermediate jib 25b are removed from the jib 25 in that order. Finally, the lower jib 25a and the strut 27 are removed from the boom 24 as a single unit.

[0048] (Crane assembly) Next, we will explain the process of assembling crane 1. This section will cover the steps from attaching the jib 25 to the lowered boom 24 to raising both the boom 24 and the jib 25.

[0049] First, as shown in Figure 6, with the boom 24 lying down on the ground, the lower jib 25a and strut 27 are attached to the boom 24 as a single unit. At this time, the strut 27 is lying down on the lower jib 25a via the support legs 2. Next, the intermediate jib 25b and upper jib 25c are attached to the lower jib 25a in that order.

[0050] Next, the connection between the fastening part on the strut 27 and the other end of the string-like member 4 is released, and the hoisting rope 32 is connected to the other end of the string-like member 4. Then, the hoisting rope 32 is wound up with the hook winch 43 to raise the strut 27.

[0051] At this time, as shown in Figure 6, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is higher than the base end of the strut 27. Therefore, when the strut 27 is lying down on the jib 25, pulling the hoisting rope 32 can generate a moment that rotates the strut 27 in the direction of raising it. This allows the strut 27 to be brought upright in a suitable position.

[0052] As shown in Figure 2, after the strut 27 is raised, the connecting part 51 on the boom 24 is connected to the strut guy line 46. The jib backstop device 47 is then supported by the backstop receiver on the strut 27, and the strut backstop device 48 is supported by the backstop receiver on the boom 24. The support legs 2, which were in the operational position, are then retracted.

[0053] Next, the connection between the string-like member 4 and the hoisting rope 32 is released, and the other end of the string-like member 4 is connected to the fastening part provided on the strut 27. Then, by winding up the boom luffing rope 41, the boom 24 is raised as shown in Figure 1.

[0054] (effect) As described above, according to the crane 1 of this embodiment, when the boom 24 and jib 25 are laid down on the ground and the strut 27 is laid down on the jib 25 via the support legs 2, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is higher than the base end of the strut 27. Therefore, when the strut 27 is laid down on the jib 25, a moment can be obtained to rotate the strut 27 in the direction of raising it by pulling the hoisting rope 32. This allows the laid-down strut 27 to be brought up to a suitable position. Furthermore, by paying out the hoisting rope 32, when laying down the upright strut 27 on the jib 25, tension can be constantly applied to the hoisting rope 32 while laying down the strut 27. This allows the upright strut 27 to be brought up to a suitable position. Furthermore, unlike Patent Document 1, there is no need to align the groove of the guide sheave provided at the tip of the boom 24 with the hoisting rope 32 in the width direction, thus improving the workability when raising the fallen strut 27 and when lowering the upright strut 27.

[0055] Furthermore, the support legs 2 are attached to the jib 25 or strut 27 with fastening members 3. By using fastening members 3, welding work is unnecessary, so the support legs 2 can be easily attached to a crane 1 that does not have support legs 2. In addition, since the support legs 2 can be removed, if the support legs 2 are removed from the jib 25 or strut 27 during the disassembly and transport of the crane 1, the transported components (lower jib 25a and strut 27) can be prevented from exceeding the transport height limit.

[0056] Furthermore, the support leg 2 can change its orientation between an upright position relative to the strut 27 side of the jib 25, or the jib 25 side of the strut 27, and a retracted position where it is folded down along the strut 27 side of the jib 25, or the jib 25 side of the strut 27. By setting the support leg 2 to the upright position, when the strut 27 is folded down onto the jib 25 via the support leg 2, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) can be made higher than the base end of the strut 27. On the other hand, by setting the support leg 2 to the retracted position, when the crane 1 is disassembled and transported, the transported components (lower jib 25a and strut 27) can be prevented from exceeding the transport height limit.

[0057] Furthermore, the hoisting rope 32 and the strut 27 are connected via the string-like member 4. By connecting one end of the string-like member 4 to the strut 27, the other end of the string-like member 4 and the hoisting rope 32 can be connected at a lower position than when the hoisting rope 32 is directly connected to the strut 27. This improves the work efficiency of connecting the strut 27 and the hoisting rope 32.

[0058] Furthermore, the length of the support legs 2 in the direction opposite to the jib 25 and strut 27 is set so that the sheave 52 does not interfere with the jib 25 when the boom 24 and jib 25 are lowered to the ground and the strut 27 is lowered onto the jib 25 via the support legs 2. Therefore, when the strut 27 is lowered, the sheave 52 does not interfere with the jib 25, thus preventing damage to at least one of the sheave 52 and the jib 25.

[0059] Furthermore, when the boom 24 and jib 25 are laid down on the ground, and the strut 27 is laid down on the jib 25 via the support legs 2, the base end of the jib 25 (lower jib 25a) and the strut 27 are attached to and detached from the boom 24 as a single unit. Therefore, when the base end of the jib 25 and the strut 27 are attached to the boom 24 as a single unit, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is higher than the base end of the strut 27. As a result, by pulling the hoisting rope 32 connected to the strut 27 via the string-like member 4, a moment to rotate the strut 27 in the direction of raising it can be easily obtained, so that the strut 27 can be preferably raised.

[0060] Furthermore, with the boom 24 and jib 25 lowered to the ground, the hoisting rope 32 is unfurled, causing the upright strut 27 to be lowered onto the jib 25 via the support legs 2. At this time, the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is always higher than the base end of the strut 27, so tension is constantly applied to the hoisting rope 32 while the strut 27 is lowered onto the jib 25 via the support legs 2. This prevents the strut 27 from falling too forcefully, thus preventing damage to the strut 27. Also, with the boom 24 and jib 25 lowered to the ground, the hoisting rope 32 is wound up, causing the lowered strut 27 on the jib 25 to be raised via the support legs 2. At this time, since the height of the part of the strut 27 to which the string-like member 4 is connected (connecting bracket 56) is always higher than the base end of the strut 27, a moment can be obtained to rotate the strut 27 in the direction of raising it until the strut 27 is raised. This makes it possible to suitably raise the fallen strut 27.

[0061] Although embodiments of the present invention have been described above, these are merely illustrative examples and do not particularly limit the present invention. Specific configurations and other aspects can be modified as appropriate. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects according to the present invention are not limited to those described in the embodiments. [Explanation of Symbols]

[0062] 1 Crane 2 Support legs 3 Fastening members 4. String-like member 21 Lower running body 22 Upper rotating body 23 Driver's cab 24 Boom 25 Jib 25a Lower jib 26 Gantry 27 strut 28 Lower spreader 29 Counterweight 31 Jib Point Sheave 32. Hoisting rope (rope) 34 Jib Guy Line 39 Boom Guyline 40 Top spreader 41 Boom luffing rope 42 Boom Foot Pin 43. Winch for hooks (winch) 45. Boom luffing winch 46 Strut Guyline 47. Jib backstop device 48 Strut backstop device 51 Connection part 52 sieves 55 Width change link 56 Connection Brackets 58, 59 brackets

Claims

1. The crane body and A boom is attached to the crane body in a manner that allows it to be raised and lowered, A jib is attached to the tip of the boom in a manner that allows it to be raised and lowered, A strut is attached to the tip of the boom or the base of the jib so as to be able to be raised and lowered, A winch provided on the crane body or the boom, A rope that is wound around the winch and detachably connected to the strut, A support leg attached to the strut-side surface of the jib, or to the jib-side surface of the strut, It has, A crane characterized in that, with the boom and jib lying on the ground, and the strut lying on the jib via the support legs, the height of the portion of the strut to which the rope is connected is higher than the base end of the strut.

2. The crane according to claim 1, further characterized by having fastening members for attaching the support legs to the jib or strut.

3. The crane according to claim 1 or 2, characterized in that the support legs are capable of changing their orientation between an upright operating position relative to the strut-side surface of the jib or the jib-side surface of the strut, and a stowed position in which they are folded down along the strut-side surface of the jib or the jib-side surface of the strut.

4. The crane according to claim 1 or 2, characterized in that it has a string-like member interposed between the strut and the rope and connecting the two.

5. The strut has a sheave provided on it, The crane according to claim 1 or 2, characterized in that, when the boom and the jib are laid down on the ground, and the struts are laid down on the jib via the support legs, the length of the support legs in the direction opposite to the jib and the struts is set so that the sheaves do not interfere with the jib.

6. The strut is attached to the base end of the jib, The crane according to claim 1 or 2, characterized in that, with the boom and the jib lying on the ground, and the strut lying on the jib via the support legs, the base end of the jib and the strut are integrally attached to and detached from the boom.

7. A method for assembling and disassembling a crane, which involves assembling and disassembling the crane described in claim 1 or 2, With the boom and jib lowered to the ground, the rope is paid out to lower the upright strut onto the jib via the support legs in a lowering step, With the boom and jib lying on the ground, the rope is wound up to raise the struts on the jib, which are in a lying position, via the support legs. A method for assembling and disassembling a crane, characterized by having the following features.

Images