JP4587764B2 - Reaction force receiving structure of climbing crane - Google Patents

Description

  The present invention relates to a reaction force receiving structure for a climbing crane.

  When constructing a building such as a low-rise building, a crane body with a frame that supports the mast on the ground is used.However, when constructing a high-rise building, the crane body should be installed as the construction progresses. Climbing cranes are used that are sequentially replaced on the upper floors of the building.

  FIG. 10 shows an example of a climbing crane employed in the construction of a conventional steel structure high-rise building. This climbing crane includes a crane 2 at the top of the mast 1 and a main body support frame 3 at the lower end of the mast 1. Has a fixed crane body 4. Further, on the outer periphery of the mast 1 at the upper part of the main body support frame 3, there is provided an upper frame 6 that can be fixed to and removed from the mast 1 by inserting / removing the lock pin 5 and can be replaced with the mast 1. A guide mast 8 that can be fixed to and removed from the mast 1 by inserting / removing the lock pin 7 is provided, and the upper frame 6 and the guide mast 8 are connected by an elevating cylinder 9. ing.

  Each of the main body support frame 3 and the upper frame 6 is provided with telescopic beams 12 and 14 that extend horizontally and extend outward in the cross direction (front and rear, left and right). Are fixed on the upper and lower beams 10a (cross members) of the steel frame via anchor bolts 11 and 13. In the figure, reference numeral 10 b denotes a pillar extending in the vertical direction constituting the building 10. The telescopic beams 12 and 14 provided on the main support frame 3 and the upper frame 6 are generally driven by expanding and contracting the telescopic beams 12 and 14 by expansion and contraction of a hydraulic cylinder 15 as shown in FIG. 11, or as shown in FIG. A system using a screw-type jack in which a nut 18 provided in the telescopic beams 12 and 14 is screwed onto a screw shaft 17 rotated by a motor 16 and the telescopic beams 12 and 14 are expanded and contracted through the nut 18 by the rotation of the screw shaft 17. Is adopted.

  Therefore, in the climbing crane shown in FIG. 10, the telescopic beam 12 of the main frame 3 is fixed to the lower beam 10a by the anchor bolt 11, and the telescopic beam 14 of the upper frame 6 fixed to the mast 1 by the lock pin 5 is used. The anchor bolt 13 is fixed to the upper layer beam 10a, and thereby the gravity W and the moment M acting on the crane body 4 are supported by the lower layer of the building 10 and the upper layer beam 10a.

  In a general climbing crane, the crane 2 can also be replaced with respect to the mast 1. At the start of work, the crane 1 is first mounted on the mast 1 fixed to the main body support frame 3. The crane main body 4 is assembled by fixing the crane 2 to the upper end of the mast 1 which has a required height by climbing the crane 2 while adding the additional mast 1 to the upper part.

  In the climbing crane of FIG. 10, in order to replace the crane body 4 upward after the construction of the upper layer of the building 10 is completed, first the remounting work of the upper gantry 6 in the unloaded state where there is no suspended load on the crane 2. I do. In order to replace the upper frame 6, first, the lock pin 7 of the guide mast 8 is pulled out from the mast 1, and the lock pin 7 is inserted into the mast 1 again at the position where the lift cylinder 9 is extended to raise the guide mast 8. Fix it. Next, after the anchor bolt 11 that fixes the telescopic beam 14 of the upper frame 6 to the beam 10a is released, the lock pin 5 of the upper frame 6 is pulled out, and the lifting cylinder 9 is reduced so that the upper frame 6 is fixed. After raising to the height, the lock pin 5 is inserted and the upper frame 6 is fixed to the mast 1. As a result, the upper frame 6 is raised by a predetermined stroke. Again, by repeating the operation of raising the upper frame 6 by a predetermined stroke in the same manner as described above, after the telescopic beam 14 of the upper frame 6 is raised to the position above the upper beam 10a, After the telescopic beam 14 is extended on the beam 10a and the elevating cylinder 9 is extended to place the telescopic beam 14 on the beam 10a, the telescopic beam 14 is fixed to the beam 10a by the anchor bolt 13. This completes the replacement of the upper frame 6.

  Next, in order to replace the crane body 4, the telescopic beam 12 of the body support frame 3 is first fixed to the beam 10a in a state where the crane body 4 is supported by the upper frame 6 replaced with the upper beam 10a as described above. After releasing the anchor bolt 11 being fixed, the telescopic beam 12 is reduced.

  Next, at the position where the lifting cylinder 9 is reduced and the guide mast 8 is lowered, the lock pin 7 of the guide mast 8 is inserted into the mast 1 and fixed, and then the lifting cylinder 9 is slightly extended to extend the upper frame 6. Thus, the weight of the crane body 4 is supported by the upper frame 6 via the lock pin 7, the guide mast 8, and the elevating cylinder 9. In this state, the lift cylinder 9 is extended and the crane body 4 is raised, and the lock pin 5 of the upper frame 6 is inserted into the mast 1 and fixed. As a result, the crane body 4 is raised by a predetermined stroke. Again, by repeating the operation of raising the crane main body 4 by a predetermined stroke in the same manner as described above, the telescopic beam 12 of the main body support gantry 3 is raised to the upper position of the upper beam 10a, and then the main body support gantry. After the telescopic beam 12 is extended onto the beam 10a and the elevating cylinder 9 is extended to place the telescopic beam 12 on the beam 10a, the telescopic beam 12 is fixed to the beam 10a by the anchor bolt 11. As a result, the replacement of the crane body 4 is completed.

  In the above climbing crane, the telescopic beams 12 and 14 provided on the main body support frame 3 and the upper frame 6 are extended outward in the horizontal direction, and the telescopic beams 12 and 14 are fixed to the beam 10a using the anchor bolts 11 and 13. Therefore, since the beam 10a receives the gravity W and the moment M acting on the crane body 4, the telescopic beams 12 and 14 need to be firmly fixed to the beam 10a. Therefore, the structure for firmly fixing the telescopic beams 12 and 14 to the beam 10a is troublesome, and there is a problem that it takes time and effort to fix and release the telescopic beams 12 and 14 with respect to the beam 10a. It has also been proposed that the telescopic beams 12 and 14 be automatically fixed and released. However, in order to automatically fix and release the telescopic beams 12 and 14, the configuration of the apparatus becomes very complicated and large. There is a problem that the weight of the main body support frame 3 and the upper frame 6 increases.

  Furthermore, although the vertical gravity W acting on the crane body 4 can be received by the beam 10a relatively easily, the moment M acting on the crane body 4 is particularly concentrated on the beam 10a particularly during crane operation. At this time, since the beam 10a is lower in strength than the column 10b, there is a problem that the beam 10a is deformed due to concentration of the load. For this reason, conventionally, as shown in FIG. 10, the beam 10 a is reinforced by the reinforcing member 19, and there is a problem that it takes a lot of time and effort to attach and remove the reinforcing member 19.

Moreover, there exists a thing shown to patent document 1 as a climbing crane. This climbing crane has a crane body with a crane at the top of the mast and a main body support frame fixed to the lower end of the mast. The main body support frame can be attached to and detached from the cross-shaped beam and each end of the beam. The extended beam is supported on the beam of the building. Each of the masts includes an upper frame and an elevating device that can be remounted by attaching and detaching a rod, and the upper frame and the elevating device are connected by an elevating cylinder. The upper frame is provided with an extension beam that extends outward in the horizontal direction and is supported on the upper or inner surface of the beam of the building or the inner surface of the column.
JP 2000-203788 A

  However, the climbing crane shown in Patent Document 1 has a basic structure in which the main body support frame is fixed on the beam by an extension beam detachably provided at each tip of the cross beam of the main body support frame. The work of attaching / detaching the extension beam to / from each tip of the cross beam and the work of fixing / releasing the main support frame with respect to the beam in the same manner as in the conventional example of FIG. There is a problem that can not climb efficiently. In addition, there is a problem that the device for fixing the extension beam to the beam becomes complicated and large, and it is necessary to reinforce the beam in order to prevent the beam from being deformed by a moment acting on the crane body during crane operation. There is a problem.

  The present invention has been made in view of the above circumstances, and the moment that acts on the crane body by pressing the reaction force receiving portion against the pillar of the building by the expansion / contraction mechanism provided on the main body support frame and the upper frame of the crane body is built. In the climbing crane reaction force receiving structure that enables simplification of climbing device configuration and handling operability by receiving with the pillars of the cylinder, the strength of the driving device that expands and contracts the expansion mechanism is increased and the driving device is downsized An object of the present invention is to provide a reaction force receiving structure for a climbing crane that can be used.

  The climbing crane reaction force receiving structure consists of a crane body with a crane at the top of the mast and a main body support frame at the lower end of the mast, an upper frame that can be resized along the mast, and a repositioning along the mast. An extension / reduction mechanism is provided on each of the main body support frame and the upper frame of the crane main body, and the reaction force receiving portion is provided by the expansion / contraction mechanism. Is a reaction force receiving structure for a climbing crane in which a moment acting on the crane body is received by the building pillar and the drive device for driving expansion / contraction of the expansion / contraction mechanism is rotated by the worm. And a nut screwed to the screw shaft, and when the expansion / contraction mechanism is expanded, the tension of the screw shaft of the driving device is pulled through the nut. It characterized in that it was set to press the force receiving a pillar of the building.

  In the above-mentioned means, it is preferable that the expansion / contraction mechanism is provided with a gravity placing portion that applies gravity acting on the crane body to the beams of the building.

  Further, the expansion / contraction mechanism is provided on the main body support frame and the upper frame, and is provided at a first stage expansion / contraction member that can be expanded / contracted in the horizontal direction by the first driving device, and a second stage expansion / contraction member. It is preferable that the second-stage expansion / contraction member includes the second-stage expansion / contraction member that can be expanded / contracted in a horizontal direction orthogonal to the expansion / contraction direction of the first-stage expansion / contraction member.

  Climbing crane reaction force receiving structure in which the reaction force receiving part of the expansion / contraction mechanism provided on the crane main body support frame and upper frame is pressed against the pillar of the building so that the moment acting on the lane body is received by the building column. In the above, the reaction force receiving portion is pressed against the pillar of the building by the pulling force of the screw shaft of the driving device, so that a strong pressing force can be applied by the small-diameter screw shaft. It is possible to achieve an excellent effect that the strength of the drive device can be increased to reduce the size of the drive device.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

   1 to 9 show an example of an embodiment for implementing a reaction force receiving structure for a climbing crane of the present invention. FIG. 1 is a schematic side view of a climbing crane to which the reaction force receiving structure of the present invention is applied. FIG. 3 is a plan view of FIG. 1 viewed from the II-II direction, FIG. 3 is a plan view showing a state in which the expansion / contraction mechanism of FIG. 1 and FIG. 2 is reduced, FIG. 4 is a view in the direction of arrows V-V in FIG. 4, FIG. 6 is a view in the direction of arrows VI-VI in FIG. 4, FIG. 7 is a side view of the first drive device, and FIG. FIG. 9 is a side view of the second drive unit, and in FIGS. 1 to 9, the same components as those shown in FIG.

  FIG. 1 shows a crane body having a crane 2 at the top of the mast 1 and a main body support frame 3 fixed to the lower end of the mast 1, and the mast 1 of the crane body 4 is inserted into the mast 1 by inserting and removing a lock pin 5. There is an upper frame 6 that can be fixed to and removed from the mast 1 so that the mast 1 can be rearranged. In addition to the upper frame 6, the upper frame 6 can be fixed to the mast 1 by inserting and removing the lock pin 7 from the mast 1. A guide mast 8 that can be separated from the mast 1 by separation is provided, and the upper frame 6 and the guide mast 8 are connected by a lifting cylinder 9.

  The main body support frame 3 and the upper frame 6 are surrounded by four columns 10b and beams 10a of the building 10 as shown in FIG. As shown in FIGS. 1 and 2, each of the upper frame 6 includes expansion / contraction mechanisms 20a and 20b that can be expanded and contracted outward in the horizontal direction.

  The expansion / contraction mechanisms 20a and 20b provided in the main body support frame 3 and the upper frame 6 have the same configuration, and therefore, the case of FIGS. 4 to 6 showing the expansion / contraction mechanism 20a provided in the main body support frame 3 is taken as an example. explain. The expansion / contraction mechanism 20a includes a beam 22 that can be expanded and contracted in the left-right width direction A in FIGS. 4 and 5 along a guide portion 21 that is horizontally and parallelly provided before and after the main body support frame 3 and the upper frame 6. Left and right first-stage expansion / contraction members 24 formed of connecting beams 23 extending in the front-rear direction (up and down in FIG. 4) for fixing the right-side end sections to each other. Is expanded or contracted in the left-right width direction A by the first drive device 25 provided on the main body support frame 3.

  As shown in FIGS. 7 and 8, the first drive device 25 includes a worm 29 and a worm wheel 30 that are driven by a drive motor 28 on a device base 27 attached to a guide portion 21 of a main body support base 3 by a swing shaft 26. And a nut 32 provided on the beam 22 of the first stage expansion / contraction member 24 is screwed onto the screw shaft 31. At this time, when the first driving device 25 expands the first-stage expanding / contracting member 24 in the A ′ direction of the left-right width direction A as shown in FIG. A drive motor 28 for rotating the screw shaft 31 is attached to the end portion of the guide portion 21 of the main body support frame 3 via the worm 29 so as to expand the expansion / contraction member 24 in the A ′ direction, and is inserted into the guide portion 21. A nut 32 is provided at a connecting portion 33 formed at the insertion side end of the first stage expansion / contraction member 24, and the nut 32 is screwed onto the screw shaft 31.

  Then, below the connecting beam 23 of the first stage expansion / contraction member 24, as shown in FIGS. 4 to 6, gravity W acting on the crane body 4 when the first stage expansion / contraction member 24 is expanded is applied to the beam 10a of the building 10. Gravity placing portion 34 is provided for loading.

  Further, the both ends of the connecting beam 23 fixed to the beam 22 of the first stage expansion / contraction member 24 are expanded and contracted in the front-rear direction B (vertical direction in FIG. 4) as shown in FIGS. A second stage expansion / contraction member 35 is provided, and the second stage expansion / contraction member 35 is a second drive having the same configuration as the first driving device 25 that drives expansion / contraction of the first stage expansion / contraction member 24. The device 36 expands and contracts in the front-rear direction B perpendicular to the left-right width direction A.

  As shown in FIG. 9, the second drive device 36 is a worm 29 driven by a drive motor 28 on a device base 27 attached to the connecting beam 23 of the first stage expansion / contraction member 24 via a swing shaft 26. The screw shaft 31 rotated by the worm wheel 30 is attached, and the nut 32 provided in the second stage expansion / contraction member 35 is screwed onto the screw shaft 31. At this time, when the second drive device 36 expands the second-stage expansion / contraction member 35 in the B ′ direction of the front-rear direction B as shown in FIG. 9, the second-stage expansion / contraction is performed by the pulling force F of the screw shaft 31. A drive motor 28 for rotating the screw shaft 31 via a worm 29 is attached to the end of the connection beam 23 of the first stage expansion / contraction member 24 so as to expand the member 35 in the B ′ direction, and is inserted into the connection beam 23. A nut 32 is provided at the connecting portion 33 formed at the insertion side end of the second stage expansion / contraction member 35, and the nut 32 is screwed onto the screw shaft 31.

  As shown in FIG. 4, the planar shape of each of the second-stage expansion / contraction members 35 is substantially L-shaped so as to be pressed against the inner corners of the four columns 10 b of the building 10. The reaction force receiving portion 37 is fixed.

  Accordingly, the first stage expansion / contraction member 24 is expanded in the A ′ direction by the first driving device 25, and the second stage expansion / contraction member 35 is expanded in the B ′ direction by the second driving apparatus 36. When the reaction force receiving portions 37 of the expansion / contraction mechanisms 20a and 20b provided on the support frame 3 and the upper frame 6 are pressed against the corners of the pillars 10b at the four corners of the building 10, the moment M acting on the crane body 4 is increased and decreased. The column 10b can be loaded via the reaction force receiving portion 37.

  In the figure, reference numeral 38 denotes a floating prevention member attached to the connecting beam 23 of the first stage expansion / contraction member 24. The floating prevention member 38 enters the lower surface of the beam 10a of the building 10 to prevent the crane body 4 from being lifted. The anti-floating member 38 is configured to be foldable by a pin 39.

  Next, the operation of the above-described embodiment will be described.

  In the configuration shown in FIGS. 1 to 9, as shown in FIGS. 1 and 4 to 6, the first driving device 25 of the expansion / contraction mechanism 20 a provided in the main body support frame 3 is driven, so that the first stage expansion / contraction member is provided. 24 is expanded in the A ′ direction so that the gravity mounting portion 34 is mounted on the beam 10a having a required height, and the second driving device 36 is further driven so that the second-stage expansion / contraction member 35 is moved to B ′. By extending in the direction, the reaction force receiving portion 37 is pressed against the inner corner portion of the pillar 10b at the four corners. At this time, the expansion of the first-stage expansion / contraction member 24 is adjusted to press one side surface of the L-shaped reaction force receiving portion 37 against one surface of the corner portion of the column 10b, and the expansion of the second-stage expansion / contraction member 35 is adjusted to L The other side surface of the letter-shaped reaction force receiving portion 37 is pressed against the other surface of the corner portion of the column 10b. Furthermore, the first driving device 25 of the expansion / contraction mechanism 20b provided in the upper frame 6 is driven to expand the first stage expansion / contraction member 24 in the A ′ direction, thereby the gravity mounting portion 34 is moved to the main body support frame 3. It is placed on the beam 10a at a higher position than the supported beam 10a, and the second driving device 36 is further driven to expand the second-stage expansion / contraction member 35 in the B ′ direction in the same manner as described above. The receiving part 37 is pressed against the pillars 10b at the four corners.

  Thereby, as shown in FIG. 1, the gravity W acting on the crane body 4 is received by the beam 10a of the building 10 by the gravity placing portion 34, and the moment M acting on the crane body 4 is received by the vertical reaction force. Since the part 37 is received by the pillar 10b by the force S pressing the pillar 10b of the building 10 in the lateral direction, the crane work is performed by the crane 2 supported by the building 10 in this way. At this time, the lift prevention member 38 is rotated downward in advance so as to enter the lower surface of the beam 10a of the building 10, thereby preventing the crane body 4 from being lifted and supporting the crane body 4 more reliably. be able to.

  Further, when the crane body 4 in FIG. 1 is re-upgraded, the method of first re-mounting the upper frame 6 and then re-mating the main body support frame 3 to climb the crane body 4 is the same as the case described in FIG. As described above, the gravity W acting on the crane body 4 is placed on the beam 10a of the building 10 by placing the gravity placement portions 34 of the expansion / contraction mechanisms 20a and 20b provided on the body support frame 3 and the upper frame 6 on the beam 10a. Thus, the moment M acting on the crane body 4 is received by the beam 10a and pushes the reaction force receiving portion 37 of the expansion / contraction mechanisms 20a, 20b provided on the main body support frame 3 and the upper frame 6 to the column 10b of the building 10. Since it was received by the pillar 10b by attaching, the crane body 4 is supported by the building 10 and climbed by a simple operation of expanding / contracting the expansion / contraction mechanisms 20a, 20b. Can, thus performing a fast climbing over conventional climbing cranes can increase the work efficiency of climbing cranes.

  At this time, the gravity W acting on the crane body 4 is received by the beam 10a by placing the gravity placing portion 34 on the beam 10a of the building 10, and the moment M acting on the crane body 4 is the vertical reaction force. Since the receiving portion 37 is pressed against the column 10b of the building 10 so as to be received by the column 10b, a conventional fixing structure for fixing the telescopic beam to the beam becomes unnecessary, and it is necessary for fixing and releasing. The number of steps and time can be reduced. Further, since the gravity W acting on the crane body 4 only acts on the beam 10a of the building 10, the beam that has been conventionally required without the problem of deformation of the beam 10a. The material for reinforcing 10a and the labor for attaching and removing it can be omitted.

  As described above, the first stage expansion / contraction member 24 is expanded in the A ′ direction by the first driving device 25, and the second stage expansion / contraction member 35 is expanded in the B ′ direction by the second driving apparatus 36. The reaction force receiving portions 37 of the expansion / contraction mechanisms 20a and 20b provided on the main body support frame 3 and the upper frame 6 are pressed against the corners of the pillars 10b at the four corners of the building 10, and the first And the second driving devices 25 and 36 are configured to expand the first-stage expansion / contraction member 24 and the second-stage expansion / contraction member 35 by the pulling force F of the screw shaft 31, as shown in FIGS. Therefore, a large pressing force can be exhibited by the small-diameter screw shaft 31.

  That is, when an attempt is made to press the reaction force receiving portion using the conventional hydraulic cylinder or screw jack shown in FIGS. 11 and 12, the reaction force receiving force is normally received by the pushing force of the hydraulic cylinder or screw jack. Therefore, there is a problem that the cylinder shaft of the hydraulic cylinder or the screw shaft of the screw-type jack buckles when trying to obtain a large pressing force. However, although the shaft diameter is designed to be large, there is a problem that the drive device becomes large and the weight increases. On the other hand, since the pressing force of the reaction force receiving portion 37 is obtained by the pulling force F of the screw shaft 31 as described above, a strong pressing force can be applied by the small-diameter screw shaft 31. Therefore, the drive devices 25 and 36 can be reduced in size.

  Further, as shown in FIG. 8, the driving devices 25 and 36 are configured so that the rotation of the screw shaft 31 is driven by the worm 29 and the worm wheel 30 that are driven by the driving motor 28. Therefore, the worm 29 can prevent the worm wheel 30 from rotating due to the reaction force and the urging force is loosened, so that the crane body 4 can be pressed and supported more reliably.

  The reaction force receiving structure of the climbing crane of the present invention is not limited to the above-described embodiment, and can be applied to the construction of a building made of concrete in addition to the construction of a steel structure. Of course, various changes can be made without departing from the scope of the invention.

It is a schematic side view which shows an example of the climbing crane to which the reaction force receiving structure of this invention is applied. It is the top view which looked at FIG. 1 from the II-II direction. It is a top view which shows the state which reduced the expansion / contraction mechanism of FIG. 1, FIG. It is an enlarged plan view of a main body support frame. It is a VV direction arrow line view of FIG. It is a VI-VI direction arrow line view of FIG. It is a side view which shows the detail of a 1st drive device. It is a VIII direction arrow line view of FIG. It is a side view which shows the detail of a 2nd drive device. It is a schematic side view which shows an example of the conventional climbing crane. It is explanatory drawing of the hydraulic cylinder which expands / contracts an expansion-contraction beam. It is explanatory drawing of the screw-type jack which expands / contracts an expansion-contraction beam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mast 2 Crane 3 Main body support frame 4 Crane main body 6 Upper frame 8 Guide mast 9 Lifting cylinder 10 Building 10a Beam 10b Column 20a Expansion / contraction mechanism 20b Expansion / contraction mechanism 24 First stage expansion / contraction member 25 First drive device (drive device)
28 Worm 31 Screw shaft 32 Nut 34 Gravity placing portion 35 Second stage expansion / contraction member 36 Second drive device (drive device)
37 Reaction force receiving part A Left-right width direction B Front-rear direction A 'Expansion direction B' Expansion direction M Moment W Gravity

Claims (3)

  A crane main body having a crane at the top of the mast and a main body support frame at the lower end of the mast, an upper frame that can be resized along the mast, a guide mast that can be resized along the mast, and the upper An extension / reduction mechanism is provided on each of the main body support frame and the upper frame of the crane body having a lifting cylinder for connecting the frame and the guide mast, and the reaction force receiving portion is pressed against the pillar of the building by the expansion / contraction mechanism. A climbing crane reaction force receiving structure in which a moment acting on a main body is received by a pillar of a building, wherein a driving device that drives expansion / contraction of the expansion / contraction mechanism includes a screw shaft that is rotated by a worm and a screw that is screwed onto the screw shaft. When the expansion / contraction mechanism is expanded, the reaction force receiving portion is pressed against the building pillar through the nut by the pulling force of the screw shaft of the driving device. The reaction force receiving structure climbing cranes, characterized in that.   The reaction force receiving structure for a climbing crane according to claim 1, wherein the expansion / contraction mechanism includes a gravity placing portion that applies gravity acting on the crane body to a beam of the building.   The expansion / contraction mechanism is provided on the main body support frame and the upper frame, and is provided with a first stage expansion / contraction member that can be expanded / contracted in a horizontal direction by a first drive device, and a second drive provided at a distal end portion of the first stage expansion / contraction member. A second-stage expansion / contraction member that can be expanded / contracted in a horizontal direction orthogonal to the expansion / contraction direction of the first-stage expansion / contraction member by an apparatus, wherein the second-stage expansion / contraction member includes the reaction force receiving portion. A reaction force receiving structure for a climbing crane according to 1 or 2.

Images