Scaffolding device and method for assembling scaffolding device

Abstract

An object of the present invention is to provide a scaffolding device that can be reduced in weight while ensuring necessary strength, and a method for assembling such a scaffolding device.SOLUTION: This pedestrian bridge includes a lower structure 2 which can be installed on a walking floor F of a pedestrian bridge A, an upper structure 5 having a support frame 3 which is attached to the lower structure 2, extends in a lateral direction crossing an extension direction of the walking floor F above the lower structure 2, and protrudes laterally beyond balustrades P, P on both sides of the pedestrian bridge A, and a pair of suspension members 4, 4 extending downward from respective portions protruding to the outside of the balustrades P, P of the support frame 3 and having lower ends facing each other in the lateral direction, and a scaffold board 6 detachably bridged between the lower ends of the suspension members 4, 4 and facing a lower surface of the walking floor F.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a scaffolding device and a method for assembling a scaffolding device. [Background technology]

[0002] When performing maintenance such as inspection and repair work on an existing footbridge, a scaffolding device such as that disclosed in Patent Document 1 may be installed on the walking floor of the footbridge.

[0003] Specifically, the scaffolding device of Patent Document 1 comprises a gate-shaped lower structure that is installed on the walking floor of the footbridge so that it can move along the extension direction of the walking floor, an upper structure that is installed on top of the lower structure and can be raised and lowered relative to the lower structure and has a hanger rail that protrudes outward from the footbridge in a horizontal direction that crosses the extension direction of the walking floor, a pair of ladder-shaped hanging members that are suspended and supported on both sides of the hanger rail so that they can move horizontally in the horizontal direction, and a work platform that is bridged between the lower ends of each hanging member and faces the underside of the walking floor.

[0004] With such a scaffolding system, workers can perform maintenance on the footbridge using the work platform or hanging members as scaffolding. In addition, in the scaffolding system of Patent Document 1, the lower structure is configured in a gate shape by combining multiple channel materials, so that even when the scaffolding system is installed on the footbridge, workers and ordinary pedestrians can pass inside the lower structure and cross the footbridge. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7307445 Summary of the Invention [Problem to be solved by the invention]

[0006] In a scaffolding system configured in this manner, the lower structure is required to be strong enough to support the upper structure, hanging members, and work floor, but if the lower structure is configured in a gate shape as in the past so that workers and general pedestrians can pass inside the lower structure, in order to improve the strength of the lower structure, it is necessary to increase the thickness of the channel material that makes up the lower structure.

[0007] This would increase the weight of the lower structure and the weight of the entire scaffolding system, which could cause problems such as making it difficult to move or transport the scaffolding system and making it difficult to assemble the lower structure.

[0008] Therefore, an object of the present invention is to provide a scaffolding device that can be made lighter while ensuring the necessary strength, and a method for assembling such a scaffolding device. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the scaffolding device of the present invention is used for maintenance of a pedestrian bridge and comprises: a lower structure that can be installed on the walking floor of the pedestrian bridge; an upper structure having support frames attached to the lower structure and extending laterally above the lower structure in a direction transverse to the extension of the walking floor of the pedestrian bridge and protruding laterally beyond the parapets on both sides of the pedestrian bridge; and a pair of hanging members extending downward from each portion of the support frames that protrudes outward from the parapets, with their lower ends facing each other laterally; and a scaffolding board detachably bridged between the lower ends of the hanging members and facing the underside of the walking floor, the lower structure comprising rectangular upper and lower frames arranged so as to face each other vertically, and four supports extending vertically and connecting the corners of the upper and lower frames. With this configuration, the lower structure is not a gate-shaped structure as in the conventional case, but is box-shaped with the four supports connecting the corners of the upper and lower frames, thereby improving the strength of the lower structure. Therefore, even if the thickness of the pillars, upper frame, and lower frame that make up the lower structure is reduced, the strength of the lower structure can be sufficiently ensured, so the scaffolding device can be made lighter without reducing its strength.

[0010] In addition, the scaffolding device of the present invention is equipped with a lifting device that can move the upper structure up and down relative to the lower structure, and the upper structure has four movable pillars that are each arranged on the side of the support pillars and can be connected to the support pillars, and whose upper ends are connected to the lower part of the support frame, and the lifting device has a movable pulley attached to each movable pillar, a pair of fixed pulleys attached to the upper frame so as to sandwich the pillars at the three corners of the upper frame, a fixed pulley and a fixing bracket attached to the upper frame so as to sandwich the pillar at the remaining corner, a rope having one end fixed to the upper frame and wound around the fixed pulley and movable pulley, and a winch around which the other end of the rope is wound and which can wind and unwind the rope, so that when the rope is wound with the winch, the four movable pillars rise in sync, and when the rope is unwound with the winch, the four movable pillars descend in sync. With this configuration, the four movable columns are suspended by a single rope, and when the winch is rotated, the four movable columns rise and fall synchronously, allowing the upper structure to be maintained in a horizontal position at all times. This eliminates the need to adjust the inclination of the upper structure to maintain a horizontal position each time the upper structure is raised or lowered relative to the lower structure, making the upper structure easier to raise and lower. Furthermore, with this scaffolding system, the rope is looped around multiple fixed pulleys on each side of the upper frame and movable pulleys on each movable column located to the side of each column. Therefore, the rope is stretched along each side of the upper frame and the movable columns, except for the section between the winch and the fixed pulley, making it difficult for workers to come into contact with the rope. This prevents workers from coming into contact with the rope during the upper structure's raising and lowering operation.

[0011] The scaffolding device 1 of the present invention also includes a lifting device that can move the upper structure up and down relative to the lower structure, and the upper structure has four movable struts that are each arranged on the side of the support struts and can be connected to the support struts via connecting fittings, and whose upper ends are connected to the lower part of the support frame. The connecting fittings have a fixed portion fixed to the outer periphery of the movable strut, an opposing portion connected to the fixed portion and facing the outer periphery of the support strut, and a fixing device having a fixed pin that is held in the opposing portion and can be inserted and removed from one of a plurality of pin holes arranged at predetermined intervals along the axial direction on the support strut. The fixing device has a case into which the fixed pin is inserted so that it can move axially, a coil spring that urges the fixed pin toward the support strut, and a stopper that abuts against a regulating piece provided on the outer periphery of the case and restricts the movement of the fixed pin toward the support strut. The stopper may have a cam piece that can switch the position of the fixed pin between a pushed-in position where it can be inserted into the pin hole and a pulled-out position where it is moved away from the support strut, depending on the abutment position with the regulating piece. With this configuration, the position of the fixing pin can be switched between the pushed-in position and the pulled-out position simply by changing the abutment position of the cam piece against the restricting piece, so the movable support can be easily attached to and detached from the support. When the fixing pin is in the pulled-out position and removed from the pin hole of the support, the movable support is released from the support, so the upper structure can be moved up and down by the lifting device. On the other hand, when the fixing pin is in the pushed-in position and inserted into the pin hole of the support, the movable support is connected to the support, and the up and down movement of the upper structure is restricted, so accidents such as the upper structure moving up and down during use of the scaffolding device can be prevented.

[0012] In the scaffolding system of the present invention, the winch may be manually operated. With this configuration, the winch does not have a drive source such as a motor, so that the winch does not become heavy, and the scaffolding system can be made lighter.

[0013] Furthermore, in the scaffolding device of the present invention, the lower structure may have a floor material installed on the lower frame, and slopes installed between the front and rear ends of the floor material and the walking floor when viewed from the extension direction of the walking floor of the footbridge. With this configuration, workers and ordinary pedestrians can walk on the slopes and the floor material and pass inside the lower structure, so even if the lower frame is connected to the bottom of each support and the lower structure is configured in a box shape, there is no risk of workers or ordinary pedestrians tripping over the lower frame.

[0014] Furthermore, in the scaffolding device of the present invention, each portion of the support frame that protrudes outside the parapet may be provided with a plurality of mounting portions arranged side by side in the horizontal direction, to which the upper ends of the hanging members can be attached. With this configuration, since the mounting portions are arranged side by side in the horizontal direction on each portion of the support frame that protrudes outside the parapet, the mounting position of the hanging member relative to the support frame can be adjusted by selecting which mounting portion the upper ends of the hanging members are attached to. Therefore, the width between the hanging members can be appropriately changed to match the horizontal width of the footbridge to be maintained.

[0015] The scaffolding system assembly method of the present invention may also include the steps of assembling a scaffolding board support unit on the ground by assembling an upper structure to a lower structure; lifting the scaffolding board support unit with a crane and placing the lower structure on a walking platform; and suspending a scaffolding board between the lower ends of the suspension members from above an aerial work platform or temporary scaffolding placed on the ground. According to this configuration, the scaffolding board support unit, consisting of a pre-assembled lower structure and upper structure, is placed on the walking platform with a crane. This significantly reduces the work time required to install the scaffolding system on the walking platform compared to assembling all components of the scaffolding system on the footbridge's walking platform. This also reduces the time the footbridge is closed to traffic during the scaffolding system installation work, thereby minimizing inconvenience to footbridge users. Furthermore, according to the above assembly method, the scaffolding board support unit, consisting of a pre-assembled lower structure and upper structure, is placed on the walking platform with a crane, eliminating the need for workers to lean over the outside of the walking platform to attach the suspension members. In addition, the work of suspending the scaffolding planks between the lower ends of the hanging members can be carried out safely on the work platform of the aerial work vehicle or on temporary scaffolding. Therefore, the above assembly method ensures extremely high safety in assembling the scaffolding device. [Effects of the Invention]

[0016] The scaffolding system of the present invention can be made lighter without reducing its strength. Furthermore, the method for assembling the scaffolding system of the present invention can significantly reduce the time required for work on the walking floor of a footbridge and improve work safety. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a front view of the scaffolding device of this embodiment with the upper structure lowered. [Figure 2] FIG. 1 is a front view of a scaffolding device according to an embodiment of the present invention with the upper structure raised. [Figure 3] FIG. 2 is a right side view showing the scaffolding device of the present embodiment with some parts omitted. [Figure 4]FIG. 1 is a perspective view showing the state in which the scaffolding device of this embodiment is installed on a footbridge. [Figure 5] FIG. 2 is an enlarged perspective view showing the connecting portion between the movable support of the upper structure and the support of the lower structure in the scaffolding device of this embodiment. [Figure 6] FIG. 2 is a plan cross-sectional view showing an enlarged view of the connecting portion between the movable support of the upper structure and the support of the lower structure in the scaffolding device of this embodiment. [Figure 7] FIG. 10 is a side cross-sectional view showing an enlarged view of the fixing device of the connecting fitting that detachably connects the movable support of the upper structure and the support of the lower structure in the scaffolding device of this embodiment, where (A) shows the state in which the connection between the movable support and the support is released, and (B) shows the state in which the movable support and the support are connected. [Figure 8] This is an oblique view showing an enlarged view of the connection point between the hanging member and the support frame in the upper structure of the scaffolding device of this embodiment. [Figure 9] FIG. 2 is an enlarged perspective view showing a part of the scaffolding device of the present embodiment. [Figure 10] FIG. 10 is a diagram showing a process of lifting the scaffolding device of this embodiment with a crane and installing it on a footbridge. DETAILED DESCRIPTION OF THE INVENTION

[0018] The scaffolding device and the method for assembling the scaffolding device of the present invention will now be described with reference to the drawings, in which like reference numerals used throughout the several views indicate like parts.

[0019] As shown in Fig. 1, the scaffolding device 1 of this embodiment is used for maintenance such as inspection and maintenance work of a pedestrian bridge A. As shown in Fig. 1, the pedestrian bridge A of this embodiment includes, for example, a pair of abutments (not shown) having a pair of staircase sections installed on either side of a road not shown, a pair of main girders B, B on the left and right in the figure that are bridged between the pair of abutments and extend in a direction crossing the road, a walking floor F that is bridged and fixed between the main girders B, B, and a pair of parapets P, P that are provided integrally above each main girder B and along the extension direction of the main girders B. However, the pedestrian bridge A may be one that is bridged over a bridge other than a road, and may be one that is bridged over a river or a railroad, for example.

[0020] As shown in Figures 1 and 2, the scaffolding device 1 of this embodiment comprises a lower structure 2 that can be installed on the walking floor F of the pedestrian bridge A, a support frame 3 that is attached to the lower structure 2 and extends horizontally above the lower structure 2 in a direction that intersects the extension direction of the walking floor F and protrudes laterally beyond the parapets P on both sides of the pedestrian bridge A, and an upper structure 5 that has a pair of hanging members 4 that extend downward from each portion of the support frame 3 that protrudes outward from the parapet P, with their lower ends facing each other laterally, and a scaffolding board 6 that is detachably spanned between the lower ends of the hanging members 4 and faces the underside of the walking floor F.

[0021] In addition, the scaffolding device 1 is equipped with a lifting device that can move the upper structure 5 up and down relative to the lower structure 2, and by moving the lower structure 2 up and down using the lifting device, the scaffolding board 6 can be moved closer to or farther from the underside of the walking floor F, as shown in Figures 1 and 2.

[0022] Each part of the scaffolding device 1 of this embodiment will be described in detail below. In the following description, the extension direction of the walking floor F of the footbridge A will also be referred to as the "front-rear direction," and the lateral direction crossing the extension direction of the walking floor F will also be referred to as the "left-right direction."

[0023] 1, 2, 3, and 4, the lower structure 2 is formed in a box shape and has a rectangular upper frame body 20 and a lower frame body 21 that are arranged so as to face each other vertically, and four supports 22 that extend in the vertical direction and connect the corners of the upper frame body 20 and the lower frame body 21. Note that in Fig. 3, part of the support frame 3 and the hanging members 4 are not shown to make it easier to understand the shape of the lower structure 2.

[0024] More specifically, as shown in Fig. 4, the upper frame 20 and the lower frame 21 each have four beams 20a, 21a, and the beams 20a, 21a are respectively connected between the upper parts and lower parts of the pillars 22 made of square pipes adjacent in the front-to-rear and left-to-right directions, thereby forming the lower structure 2. In this embodiment, the beams 20a, 21a and the pillars 22 are made of square pipes, but they may also be made of round pipes.

[0025] As described above, in this embodiment, the lower structure 2 is not a conventional gate type, but is formed in a box shape by connecting the corners of the upper frame body 20 and the lower frame body 21 with four supports 22, thereby improving the strength of the lower structure 2. Therefore, even if the thickness of the supports 22 constituting the lower structure 2 and the beams 20a, 21a of the upper frame body 20 and the lower frame body 21 is reduced, the strength of the lower structure 2 can be sufficiently ensured, and the weight of the scaffolding device 1 can be reduced without reducing the strength.

[0026] A ring 22a is provided at the upper end of each support pillar 22. A roller 7 is rotatably attached to the lower end of each support pillar 22, allowing the lower structure 2 to move on the walking floor F. Therefore, the installation position of the scaffolding device 1 can be moved to match the location where maintenance of the footbridge A is to be performed.

[0027] As shown in FIG. 3 , a plurality of jacks 8 capable of lifting the lower structure 2 relative to the walking floor F are provided at the lower end of the lower frame 21. Each jack 8 has a cylindrical, bottomed body 8a connected to the lower end of the lower frame 21 and rod-like legs 8b that are threaded into threaded holes formed in the bottom of the body 8a and are axially movable relative to the body 8a. Therefore, when the legs 8b are rotated in the circumferential direction, the legs 8b move up and down relative to the lower frame 21. When the legs 8b of each jack 8 are moved downward, the lower structure 2 is lifted by the jack 8, and the rollers 7 are separated from the walking floor F, making the lower structure 2 immovable. Conversely, when the legs 8b of the jack 8 are moved upward and separated from the walking floor F, the rollers 7 are in contact with the walking floor F, allowing the lower structure 2 to move on the walking floor F.

[0028] Therefore, the scaffolding device 1 of this embodiment can be switched between a state in which it can run on the walking floor F and a state in which it is fixed to the walking floor F by moving the legs 8b of the jacks 8 up and down. The number and positions of the jacks 8 may be determined appropriately depending on the size of the lower frame 21, etc. However, the rollers 7 may be omitted, and the jacks 8 may also be omitted.

[0029] As shown in Figures 1, 2, 3, and 4, the lower structure 2 also includes a floor material 9 that is spanned between opposing beams 21a, 21a in the fore-and-aft direction of the lower frame body 21, and two slopes 10 that are installed between the front and rear ends of the floor material 9 and the walking floor F, respectively.

[0030] Therefore, workers and ordinary pedestrians can walk on the slope 10 and floor material 9 and pass inside the lower structure 2, so even though the lower frame body 21 is connected to the bottom of each support 22 and the lower structure 2 is configured in a box shape, there is no risk of workers or ordinary pedestrians tripping over the lower frame body 21 connected to the bottom of the support 22.

[0031] Furthermore, the floor material 9 is a flat horizontal plate, and the slope 10 is an inclined plate that slopes from the walking floor F toward the front or rear end of the floor material 9, so there are no steps. Therefore, even wheeled vehicles such as wheelchairs and strollers can easily pass inside the lower structure 2.

[0032] In this way, with the scaffolding device 1 of this embodiment, even when maintenance work is being performed on the footbridge A, ordinary pedestrians can pass inside the substructure 2 and cross the footbridge A, so there is no need to close the footbridge A to traffic.

[0033] Furthermore, handrail frames 11 are installed on both the left and right sides of the floor material 9. The handrail frame 11 has a pair of front and rear handrail posts 11a, 11a, a pair of upper and lower handrail rails 11b spanning between the handrail posts 11a, 11a, and a reinforcing beam 11c spanning between the handrail rails 11b, 11b. A pair of front and rear sockets (not shown) are provided on both the left and right sides of the floor material 9, and the handrail frame 11 is installed by inserting the pair of front and rear handrail posts 11a, 11a into the pair of front and rear sockets. This prevents workers and ordinary pedestrians walking on the floor material 9 from stepping off the floor material 9.

[0034] However, if it is acceptable to have a step between the walking floor F and the floor material 9, the slope 10 may be omitted. Also, if the vehicle passes inside the lower structure 2 while straddling the front and rear beams 21a, 21a of the lower frame 21, the floor material 9 may also be omitted. Also, the handrail frame 11 may also be omitted.

[0035] 1, 2, and 3, weights 12 are attached to the left and right beams 21a, 21a of the lower frame 21. The weights 12 are box-shaped and contain multiple weights, so their weight can be adjusted by increasing or decreasing the number of weights. Because the weight of the weights 12 can be adjusted in this way, when moving the scaffolding device 1, the number of weights can be reduced to lighten the weight of the weights 12, making it easier to move the scaffolding device 1. When fixing the scaffolding device 1 to the walking floor F, the number of weights can be increased to make the weight of the weights 12 heavier, preventing the scaffolding device 1 from moving or falling over due to external forces such as wind.

[0036] However, instead of the weights 12, for example, a belt or a connector that connects the lower structure 2 to the parapet P of the footbridge A may be provided to prevent the scaffolding device 1 from moving or collapsing due to external forces such as wind. Also, if the scaffolding device 1 is not likely to move or collapse due to external forces such as wind, the weights 12 may be omitted.

[0037] Next, the superstructure 5 will be described in detail. As shown in Figures 1 and 2, the superstructure 5 comprises four movable columns 50 that are arranged on the inside sides of the four columns 22 so as to correspond to the four columns 22, respectively, and are connectable to the columns 22, a support frame 3 that is connected to the upper ends of the movable columns 50 and extends along the horizontal direction, and protrudes laterally beyond the parapets P, P that are arranged on both the left and right sides of the footbridge A, and a pair of hanging members 4, 4 that extend downward from each portion of the support frame 3 that protrudes outward from the parapet P, with their lower ends facing each other in the horizontal direction.

[0038] 5, the movable support 50 is a square pipe extending in the vertical direction, and is arranged on each side of the support 22 so that the corners face each other. A connecting fitting 51 is provided on the lower end side of the movable support 50, which can detachably connect the movable support 50 to the support 22.

[0039] 5 and 6, the connecting fitting 51 includes a fixing portion 52 fixed to the outer periphery of the movable support column 50, an opposing portion 53 connected to the fixing portion 52 via a connecting portion 54 and opposing the outer periphery of the support column 22, and a fixing device 55 having a fixing pin 56 that is held by the opposing portion 53 and can be extended or retracted toward the support column 22. In addition, each surface of the support column 22 is provided with a plurality of pin holes 22b arranged at predetermined intervals along the axial direction. The fixing pin 56 of the fixing device 55 can be inserted or removed from the pin holes 22b of the support column 22, thereby allowing the movable support column 50 to be detachably connected to the support column 22.

[0040] 6, the connecting fitting 51 has a connecting fitting main body 51a configured by connecting the bottom surfaces of the connecting pieces 54a of two connecting members, each of which consists of a rectangular plate-shaped connecting piece 54a and first and second opposing pieces 52a and 53a that slope outward from each longitudinal end of the connecting piece 54a, with bolts 51a1 and nuts 51a2. The angle formed by the connecting piece 54a and each of the opposing pieces 52a and 53a is set to 135 degrees, and therefore the angle between the first opposing pieces 52a and 52a of each connecting member and the angle between the second opposing pieces 53a and 53a are both 90 degrees.

[0041] As shown in FIG. 6 , the fixing part 52 is formed by two first opposing pieces 52a, 52a of the connecting fixture main body 51a and is formed in an L-shape in a plan view. Each of the first opposing pieces 52a has a plurality of holes (not shown). With each of the first opposing pieces 52a, 52a abutting against two sides of the movable support column 50 facing the support column 22, bolts 52a1 are inserted into the plurality of holes formed in each of the first opposing pieces 52a, 52a and the plurality of holes (not shown) provided in the movable support column 50, and nuts 52a2 are screwed onto the threads of the bolts 52a1 and tightened, thereby fixing the fixing part 52 to the outer periphery of the movable support column 50. The shape of the fixing part 52 is not limited to the L-shape and may be, for example, a rectangular tubular shape. Alternatively, if the movable support column 50 is cylindrical, the fixing part 52 may be arc-shaped. Furthermore, the method of fixing the fixed portion 52 to the movable support 50 is not particularly limited, and may be, for example, welding.

[0042] 6, the facing portion 53 is configured by two second facing pieces 53a, 53a of the connecting fitting main body 51a, and is formed in an L-shape in a plan view, with each second facing piece 53a, 53a being disposed to face two sides of the support 22 on the movable support 50 side. Note that the shape of the facing portion 53 is not limited to an L-shape and may be, for example, a rectangular tube shape. Alternatively, if the support 22 is cylindrical, the facing portion 53 may be arc-shaped.

[0043] Furthermore, the connecting portion 54 is configured by connecting two connecting pieces 54a, 54a of the connecting fitting main body 51a, and connects the fixed portion 52 and the opposing portion 53. However, the shape of the connecting portion 54 is not particularly limited as long as it can connect the fixed portion 52 and the opposing portion 53.

[0044] In this embodiment, the connecting fitting main body 51a is formed by connecting the bottom surfaces of the connecting pieces 54a of two connecting members, each of which consists of a rectangular plate-shaped connecting piece 54a and a first opposing piece 52a and a second opposing piece 53a that respectively incline outward from each longitudinal end of the connecting piece 54a, but it may also be formed from a single member.

[0045] Returning to the above, an attachment hole 53a1 is formed near the center of the second opposing piece 53a, and a fixing device 55 is inserted and held in the attachment hole 53a1 of each second opposing piece 53a. In this manner, in this embodiment, two fixing devices 55 are held in the opposing portion 53. However, the number of fixing devices 55 may be one, or three or more.

[0046] As shown in Figure 7, the fixing device 55 comprises a case 57 which is connected to the second opposing piece 53a when inserted into the mounting hole 53a1 of the second opposing piece 53a, stands vertically on the side opposite the support pillar of the second opposing piece 53a, and has a fixing pin 56 inserted therein so as to be movable axially, a coil spring 58 which urges the fixing pin 56 toward the support pillar 22, and a stopper 59 which abuts against a regulating piece 57e provided on the outer periphery of the case 57 and regulates the movement of the fixing pin 56 toward the support pillar 22.

[0047] The case 57 comprises a cylindrical outer tube portion 57a ​​welded to the second opposing piece 53a with its tip (left end in Figure 7), which is the end on the support 22 side, inserted into the mounting hole 53a1 of the second opposing piece 53a so as to protrude slightly toward the support 22, and a cylindrical inner tube portion 57d inserted into the outer tube portion 57a ​​from the anti-support side and connected to the outer tube portion 57a ​​with its base end, which is the anti-support side, protruding from the outer tube portion 57a.

[0048] More specifically, an annular flange piece 57c is provided on the outer periphery of the base end (right end in FIG. 7), which is the end of the outer tubular portion 57a ​​opposite to the support pillar.

[0049] An annular restricting piece 57e is provided on the outer periphery of the inner cylindrical portion 57d, protruding outward from near the axial center and abutting the anti-pillar side of the flange piece 57c, and an annular spring bearing portion 57f is provided on the inner periphery of the inner cylindrical portion 57d, protruding inward from near the axial center. Further, a pair of elongated holes 57g facing each other in the radial direction are formed in the inner cylindrical portion 57d on the anti-pillar side of the restricting piece 57e, and each elongated hole 57g is formed so as to be long along the axial direction of the inner cylindrical portion 57d.

[0050] Then, bolts 57h are inserted into two opposing holes (not shown) provided in a flange piece 57c provided on the outer cylindrical portion 57a ​​and a regulating piece 57e provided on the inner cylindrical portion 57d, and nuts 57i are screwed onto the threaded portions of each bolt 57h and tightened, thereby connecting the outer cylindrical portion 57a ​​and the inner cylindrical portion 57d.

[0051] An annular plate 57b is attached to the outer periphery of the tip of the outer cylindrical portion 57a, and the annular plate 57b is connected to the second opposing piece 53a by inserting bolts 57j into a plurality of opposing holes (not shown) provided in the annular plate 57b and the second opposing piece 53a and tightening nuts 57k onto the threads of the bolts 57j. The thickness of the annular plate 57b is formed to be slightly thinner than the gap between the second opposing piece 53a and the support column 22, so the gap formed between the annular plate 57b and the support column 22 is very small. Therefore, even if the movable support column 50 swings toward the support column 22, the annular plate 57b immediately comes into contact with the support column 22, thereby suppressing rattle of the movable support column 50 toward the support column 22.

[0052] 7, the fixing pin 56 has, in order from the support 22 side (left side in FIG. 7), a tip-side shank 56a whose outer diameter is slightly smaller than the diameter of the pin hole 22b of the support 22, an intermediate shank 56b whose outer diameter is larger than that of the tip-side shank 56a and smaller than the inner diameter of the inner cylindrical portion 57d, and a base-side shank 56c whose outer diameter is slightly smaller than the inner diameter of the spring bearing portion 57f and smaller than that of the intermediate shank 56b. In addition, the base-side shank 56c is provided with a hole (not shown) that radially penetrates the base-side shank 56c at a position radially opposite to the elongated hole 57g provided in the inner cylindrical portion 57d.

[0053] The coil spring 58 is interposed between the spring receiving portion 57f and a step formed at the boundary between the intermediate shaft portion 56b and the base end shaft portion 56c, and biases the fixing pin 56 toward the support 22 (left side in FIG. 7).

[0054] 6 and 7, the stopper 59 includes a pair of disk-shaped cam pieces 59a, 59a arranged to sandwich the inner cylindrical portion 57d from the left and right when viewed in the axial direction of the inner cylindrical portion 57d, and a U-shaped handle piece 59b connecting opposing circumferential portions of the cam pieces 59a, 59a, and each cam piece 59a has opposing holes (not shown) formed in a position eccentric from the center of the cam piece 59a. A bolt shank 59c is inserted into the holes formed in the cam pieces 59a, 59a of the stopper 59, the elongated hole 57g of the inner cylindrical portion 57d, and the hole formed in the base-end shaft portion 56c of the fixing pin 56, and a nut 59d is screwed onto the threaded portion of the bolt shank 59c and tightened, whereby the stopper 59 is rotatably connected to the base-end shaft portion 56c of the fixing pin 56 with the bolt shank 59c as the rotation axis. Furthermore, because the bolt shank 59c is inserted into an elongated hole 57g that extends along the axial direction of the inner cylindrical portion 57d, movement of the bolt shank 59c within the elongated hole 57g is permitted, thereby allowing axial movement of the stopper 59 and the fixing pin 56 relative to the inner cylindrical portion 57d. Note that instead of the elongated hole 57g, a notch may be formed by cutting out the base end of the inner cylindrical portion 57d to allow movement of the bolt shank 59c within the notch, thereby allowing axial movement of the stopper 59 and the fixing pin 56 relative to the inner cylindrical portion 57d. Alternatively, the axial length of the inner cylindrical portion 57d may be shortened or the axial length of the fixing pin 56 may be lengthened, and the stopper 59 may be connected via the bolt shank 59c to a portion of the fixing pin 56 that does not always face the inner cylindrical portion 57d. Even in this case, axial movement of the stopper 59 and the fixing pin 56 relative to the inner cylindrical portion 57d is permitted.

[0055] 7, the cam piece 59a of the stopper 59 faces the surface of the restricting piece 57e of the case 57 on the side opposite to the support pillar 22 in the axial direction of the inner cylindrical portion 57d. Because the fixing pin 56 is biased toward the support pillar 22 by the biasing force of the coil spring 58, the stopper 59 connected to the base-end shaft portion 56c of the fixing pin 56 also tries to move toward the support pillar 22 together with the fixing pin 56, but the cam piece 59a abuts against the surface of the restricting piece 57e on the side opposite to the support pillar 22, restricting the movement of the fixing pin 56 toward the support pillar 22.

[0056] Here, since the bolt shaft 59c is located at a position eccentric to the center of the cam piece 59a, when viewed from the axial direction of the bolt shaft 59c, each end of the cam piece 59a that intersects with the line passing through the center of the cam piece 59a and the center of the bolt shaft 59c has a different distance to the bolt shaft 59c. Therefore, when the end of the cam piece 59a that intersects with the line passing through the center of the cam piece 59a and the center of the bolt shaft 59c is defined as the first abutment portion 59a1, and the end closest to the bolt shaft 59c is defined as the second abutment portion 59a2, when the first abutment portion 59a1 of the cam piece 59a abuts against the regulating piece 57e as shown in Figure 7(A), the bolt shaft 59c is positioned displaced toward the opposite side of the support by the difference between the distance from the first abutment portion 59a1 to the bolt shaft 59c and the distance from the second abutment portion 59a2 to the bolt shaft 59c, compared to when the second abutment portion 59a2 of the cam piece 59a abuts against the regulating piece 57e as shown in Figure 7(B). Furthermore, since the bolt shaft 59c passes through the fixed pin 56 and is connected to the fixed pin 56, when the first abutment portion 59a1 of the cam piece 59a abuts against the regulating piece 57e, the fixed pin 56 is also positioned in a position displaced toward the opposite support by the difference between the distance from the first abutment portion 59a1 to the bolt shaft 59c and the distance from the second abutment portion 59a2 to the bolt shaft 59c, as compared to when the second abutment portion 59a2 of the cam piece 59a abuts against the regulating piece 57e, as shown in Figure 7(B). Conversely, when the second abutment portion 59a2 of the cam piece 59a abuts against the regulating piece 57e, the fixing pin 56 is positioned in a position displaced toward the support 22 by the difference between the distance from the first abutment portion 59a1 to the bolt shaft 59c and the distance from the second abutment portion 59a2 to the bolt shaft 59c, compared to when the first abutment portion 59a1 of the cam piece 59a abuts against the regulating piece 57e.

[0057] In other words, in the fixing device 55 of this embodiment, the axial position of the fixing pin 56 can be displaced by the difference between the distance between the first abutment portion 59a1 and the bolt shaft 59c and the distance between the second abutment portion 59a2 and the bolt shaft 59c.

[0058] As shown in Figure 7(A), when the first abutment portion 59a1 of the cam piece 59a abuts against the regulating piece 57e, the tip of the tip side shaft portion 56a is located slightly on the opposite side to the support pillar 22 from the end of the outer tube portion 57a, which is the opening end of the case 57, and the fixing pin 56 is housed within the case 57 so that the tip side shaft portion 56a does not protrude from the opening end of the case 57, and is positioned in a withdrawn position away from the support pillar 22. 7(B), when the second contact portion 59a2 of the cam piece 59a contacts the restriction piece 57e, the fixing pin 56 is displaced toward the support column 22 from the state in which the first contact portion 59a1 of the cam piece 59a contacts the restriction piece 57e by the difference between the distance from the first contact portion 59a1 to the bolt shaft 59c and the distance from the second contact portion 59a2 to the bolt shaft 59c, so that the tip side shaft portion 56a of the fixing pin 56 protrudes toward the support column 22 from the open end of the case 57, and the fixing pin 56 is positioned at a pressed-in position where it can be inserted into the pin hole 22b of the support column 22. Therefore, when the fixing pin 56 is switched to the pressed-in position with the fixing pin 56 facing the pin hole 22b of the support column 22, the fixing pin 56 is inserted into the pin hole 22b of the support column 22, and the movable support column 50 is connected to the support column 22.

[0059] That is, in the fixing device 55, the position of the fixing pin 56 can be switched between a pushed-in position where it can be inserted into the pin hole 22b and a pulled-out position where it is separated from the support 22, depending on the abutment position of the cam piece 59a with the restricting piece 57e.

[0060] In this embodiment, the cam piece 59a is disk-shaped, and the bolt shaft 59c is inserted into a hole provided at a position eccentric to the center of the cam piece 59a, thereby providing the cam piece 59a with a first abutment portion 59a1 and a second abutment portion 59a2 at different distances from the bolt shaft 59c. However, the shape of the cam piece 59a may be a shape other than a perfect circle, such as an ellipse, and the first abutment portion 59a1 and the second abutment portion 59a2 at different distances from the bolt shaft 59c may be provided.

[0061] Furthermore, handle piece 59b is provided between first contact portion 59a1 and second contact portion 59a2 in the circumferential direction of cam piece 59a. In the present embodiment, stopper 59 is coupled to base-end shaft portion 56c of fixing pin 56 so that handle piece 59b faces upward when first contact portion 59a1 of cam piece 59a faces regulation piece 57e as shown in Fig. 7(A), and so that handle piece 59b faces downward when second contact portion 59a2 of cam piece 59a faces regulation piece 57e as shown in Fig. 7(B). The position of the handle piece 59b when the first abutment portion 59a1 of the cam piece 59a abuts against the regulating piece 57e and when the second abutment portion 59a2 of the cam piece 59a abuts against the regulating piece 57e may be upside down, but as in this embodiment, if the handle piece 59b is facing downward when the second abutment portion 59a2 of the cam piece 59a abuts against the regulating piece 57e, there is no risk of the stopper 59 rotating due to gravity even if the coil spring 58 is damaged, so that it is possible to prevent an accident such as the fixed pin 56 suddenly coming out of the pin hole 22b of the support 22 during use of the scaffolding device 1 and causing the upper structure 5 equipped with the movable support 50 to fall.

[0062] Next, the operation of the fixing device 55 will be described. First, the operation of switching from a state in which the tip-side shaft portion 56a of the fixing pin 56 protrudes from the open end of the case 57, as shown in FIG. 7(B), to a state in which the tip-side shaft portion 56a of the fixing pin 56 is housed within the case 57, as shown in FIG. 7(A), will be described. The operator grasps the handle piece 59b and pulls the stopper 59 toward the opposite side from the support column against the biasing force of the coil spring 58, thereby separating the cam piece 59a from the restricting piece 57e. In this state, the operator rotates the stopper 59 until the first abutment portion 59a1 of the cam piece 59a faces the restricting piece 57e. Then, when the operator releases the handle piece 59b, the first abutment portion 59a1 abuts against the restricting piece 57e due to the biasing force of the coil spring 58, and the tip-side shaft portion 56a of the fixing pin 56 is housed within the case 57. This releases the connection between the movable support column 50 and the support column 22, allowing the movable support column 50 to move up and down relative to the support column 22.

[0063] Next, we will explain the operation of switching from a state in which the tip-side shaft portion 56a of the fixing pin 56 is housed within the case 57 as shown in Fig. 7(A) to a state in which the tip-side shaft portion 56a of the fixing pin 56 protrudes from the open end of the case 57 as shown in Fig. 7(B). The operator grasps the handle piece 59b and pulls the stopper 59 toward the side away from the support pillar against the biasing force of the coil spring 58, thereby separating the cam piece 59a from the restricting piece 57e. In this state, the operator rotates the stopper 59 until the second abutment portion 59a2 of the cam piece 59a faces the restricting piece 57e. Then, when the handle piece 59b is released with the tip side shaft portion 56a of the fixing pin 56 facing the pin hole 22b of the support 22, the second abutment portion 59a2 comes into contact with the restricting piece 57e due to the biasing force of the coil spring 58, so that the tip side shaft portion 56a of the fixing pin 56 protrudes from the open end of the case 57 and is inserted into the pin hole 22b of the support 22. Then, the vertical movement of the movable support 50 relative to the support 22 is restricted, and the movable support 50 is connected to the support 22.

[0064] In this way, in the connecting fitting 51 of this embodiment, the fixing pin 56 can be easily inserted into and removed from the pin hole 22b of the support 22 simply by rotating the stopper 59, so that the movable support 50 can be easily attached to and detached from the support 22.

[0065] When the fixed pin 56 is removed from the pin hole 22b of the support 22, the movable support 50 is released from connection to the support 22, allowing the upper structure 5 to be moved up and down using the lifting device described below.When the fixed pin 56 is inserted into the pin hole 22b of the support 22, the movable support 50 is connected to the support 22, restricting the up and down movement of the upper structure 5, thereby preventing accidents such as the upper structure 5 moving up and down while the scaffolding device 1 is in use.

[0066] Furthermore, in the connecting fitting 51 of this embodiment, the fixing device 55 is integrated into the connecting fitting 51, so that the fixing pin 56 can be prevented from falling to the ground or being lost.

[0067] However, the configuration of the fixing device 55 is one example, and is not particularly limited as long as the fixing pin 56 can be inserted into and removed from the pin hole 22b of the support 22. Furthermore, the configuration of the connecting fitting 51 described above is one example, and the configuration of the connecting fitting 51 is not particularly limited as long as it can detachably connect the movable support 50 to the support 22 at any position in the axial direction.

[0068] Returning to the above, a support frame 3 is connected to the upper end of each movable support column 50. The support frame 3 has a pair of front and rear support beams 30, 30 extending laterally and an intermediate beam 31 spanning the support beams 30 so as to connect their midpoints, forming an H-shape in plan view. The support beam 30 is a truss beam having a pair of upper and lower chord members 30a and 30b, and a lattice 30c connecting the upper chord member 30a and the lower chord member 30b, where the upper chord member 30a is made of a round pipe and the lower chord member 30b is made of a square pipe. The intermediate beam 31 is also a truss beam having an upper chord member, a lower chord member, and a lattice. As described above, the support frame 3 of this embodiment is configured by combining a pair of support beams 30, 30 made of truss beams with the intermediate beam 31, thereby increasing the bending strength of the support frame 3.

[0069] The support frame 3 may be constructed by combining multiple pipe-shaped beams as long as the bending strength is sufficient. However, in this case, if an attempt is made to ensure bending strength equivalent to that of the support frame 3 of this embodiment, which is constructed by combining multiple truss beams, it would be necessary to increase the thickness of each beam, which could result in an increase in the weight of the support frame 3. Therefore, by constructing the support frame 3 by combining multiple truss beams, as in this embodiment, it is possible to avoid an increase in weight while ensuring the necessary bending strength.

[0070] In addition, mounting holes 30b1 are provided on both the left and right sides of the lower chord 30b of the support beam 30, which is the part of the support frame 3 that protrudes outward from the parapet P on both the left and right sides in Figure 1, in a row along the horizontal direction, serving as multiple mounting portions to which the upper ends of the hanging members 4 can be attached.

[0071] As shown in Figures 1 and 4, the hanging member 4 comprises a pair of front and rear ladder-like frames 40, 40 each having a pair of left and right vertical beams 40a, 40a and a plurality of horizontal members 40b suspended vertically at a predetermined interval between the pair of vertical beams 40a, 40a, a lower scaffolding plate 41 suspended between the lowest horizontal members 40b, 40b of the pair of ladder-like frames 40, 40, and an upper scaffolding plate 42 suspended between the horizontal members 40b, 40b located slightly lower than the top end of the parapet P when the upper structure 5 is in its lowest position relative to the lower structure 2 as shown in Figure 1.

[0072] As shown in Fig. 8, a pair of front and rear mounting pieces 40a1, 40a1 protruding upward is provided at the upper end of each vertical beam 40a. Opposing holes (not shown) are formed in each mounting piece 40a1, and the distance between the pair of mounting pieces 40a1, 40a1 is slightly wider than the width of the lower chord member 30b in the front-to-rear direction. Here, as shown in Fig. 8, on both the left and right sides of the lower chord member 30b, two mounting hole groups each having a plurality of mounting holes 30b1 provided along the extension direction (lateral direction) of the lower chord member 30b are provided at an interval equal to the width between the pair of vertical beams 40a, 40a of the ladder-shaped frame 40.

[0073] 8, a pair of mounting pieces 40a1, 40a1 are brought close to the lower chord member 30b from below, and the lower chord member 30b is fitted between the pair of mounting pieces 40a1, 40a1 from below so as to sandwich the lower chord member 30b, and bolts 43 are inserted into the holes of the opposing mounting pieces 40a1 and any mounting hole 30b1 of the lower chord member 30b, and nuts (not shown) are screwed onto the threads of the bolts 43 to tighten them, thereby connecting the upper ends of the vertical beams 40a to the support frame 3. Then, by connecting the upper ends of all of the vertical beams 40a of the pair of ladder-shaped frames 40, 40 to the support frame 3 as described above, the upper ends of the hanging members 4 are connected to the support frame 3.

[0074] In this case, since multiple mounting holes 30b1 are provided along the extension direction (horizontal direction) of the lower chord 30b, the mounting position of the hanging member 4 relative to the support frame 3 can be adjusted by selecting which mounting hole 30b1 to attach the mounting piece 40a1 to. Therefore, the distance between the left and right hanging members 4, 4 can be changed appropriately to match the lateral width of the footbridge A that is the target of maintenance.

[0075] In this embodiment, the support frame 3 is provided with mounting holes 30b1 as mounting portions to which the upper ends of the hanging members 4 can be attached, but the configuration of the mounting portion is not particularly limited as long as it is possible to attach the upper ends of the hanging members 4. For example, the mounting portion may be an upward hook protruding in the front-to-rear direction from the support frame 3, and a hook portion having a hole may be provided at the upper end of the hanging member 4, and the upper end of the hanging member 4 may be attached to the support frame 3 by hooking the hook onto the hook. However, if there is no need to adjust the distance between the left and right hanging members 4, 4, the hanging members 4 may be integrally connected to the support frame 3 by welding or the like.

[0076] Although not shown, the upper scaffolding plate 42 is provided with a hatch door that opens and closes the opening that leads to the lower scaffolding plate 41. Therefore, a worker can move from the footbridge A onto the upper scaffolding plate 42, open the hatch door, and then climb down through the opening in the upper scaffolding plate 42 while using the ladder-like frame 40 as a ladder to move to the lower scaffolding plate 41.

[0077] Although not described in detail, baseboards 45 are installed at the front and rear ends and left and right ends of the outer periphery of the lower scaffolding plate 41 and the upper scaffolding plate 42 on the side opposite the footbridge, to prevent tools and the like from falling from the lower scaffolding plate 41 and the upper scaffolding plate 42. Furthermore, as shown in Figure 4, two truss-shaped handrail frames 46, 46 are attached, lined up one above the other, between the vertical beams 40a, 40a located on the side opposite the footbridge of the pair of ladder-shaped frames 40, 40. The two handrail frames 46, 46 are positioned above the lower scaffolding plate 41 and the upper scaffolding plate 42, respectively, to prevent workers from falling from the lower scaffolding plate 41 and the upper scaffolding plate 42.

[0078] The vertical length of the hanging members 4 configured in this manner is set so that, when the upper structure 5 is raised to its highest position by the lifting device, the lower ends of the hanging members 4 face each other below the main girder B of the footbridge A, as shown in Fig. 1. Also, as shown in Fig. 1, a horizontal member 47 is suspended in the front-to-rear direction between the lower ends of the two vertical beams 40a, 40a arranged on the opposing sides of the footbridge A in each hanging member 4. A scaffolding board 6, which will be described later, is suspended between the horizontal members 47, 47 provided at the lower ends of each hanging member 4.

[0079] Specifically, as shown in Fig. 1, a holding fitting 48 having a U-shaped cross section that opens downward is provided at the lower end of the vertical beam 40a of each hanging member 4 that is arranged on the pedestrian bridge A side. Then, with a horizontal member 47 made of a cylindrical pipe material inserted inside each of the holding fittings 48 that face each other in the front-to-rear direction, a bolt (not shown) is inserted so as to penetrate the holding fitting 48 and the horizontal member 47 in the horizontal direction, and a nut (not shown) is screwed onto the threaded portion of the bolt and tightened, so that the horizontal member 47 is spanned between the lower ends of the vertical beams 40a, 40a on the pedestrian bridge A side that face each other in the front-to-rear direction.

[0080] Note that the configuration in this embodiment in which the horizontal member 47 is bridged between the lower ends of the vertical beams 40a, 40a on the pedestrian bridge A side that face each other in the front-to-rear direction is one example, and is not limited to the above-mentioned configuration. Also, in this embodiment, the horizontal member 47 is configured as a cylindrical pipe material, but this is one example, and it does not have to be a pipe material. For example, the horizontal member 47 may be solid, or may be formed with a square cross section.

[0081] Next, the scaffolding plank 6 of this embodiment will be described in detail. As shown in Fig. 1, the scaffolding plank 6 is a plate material that is longer than the width between the cross members 47, 47. Furthermore, a plurality of hooks 6a with a U-shaped cross section are provided along the front-to-rear direction on both the left and right sides of the lower end of the scaffolding plank 6 in Fig. 1, and the left and right hooks 6a, 6a are hooked onto each of the cross members 47, so that the scaffolding plank 6 is spanned between the cross members 47, 47.

[0082] In addition, opposing holes (not shown) are formed on the lower end of the side wall (not shown) of the hook 6a, which has a U-shaped cross section, and by inserting pins 60 into each of these holes, the scaffolding board 6 is prevented from floating up and falling off.

[0083] In this embodiment, the plurality of hooks 6a are arranged in a row along the front-to-rear direction at the lower end of the scaffolding board 6, but the hooks 6a may be configured as a single member that extends continuously along the front-to-rear direction. However, the configuration of the hooks 6a in this embodiment is an example and is not limited to the configuration described above.

[0084] 1 and 2, bottomed cylindrical support brackets 62 into which handrail posts 61 can be removably inserted are provided at the center of each of the front and rear ends of the scaffolding plank 6. Furthermore, as shown in FIG. 1, when the upper structure 5 is at its lowest position relative to the lower structure 2, the handrail posts 61 are inserted into the support brackets 62, and two handrail rods 63 are installed side by side, one above the other, between the handrail posts 61 and the vertical beams 40a on the footbridge A side of each hanging member 4. Therefore, in this embodiment, the periphery of the scaffolding plank 6 can be surrounded by the handrail rods 63 and the hanging members 4, allowing workers to work safely on the scaffolding plank 6.

[0085] In this embodiment, one end of the handrail rod 63 is provided with an L-shaped first bracket 64 that is detachably attached to the handrail support post 61, and the other end of the handrail rod 63 is provided with a second bracket 65 that is detachably attached to the vertical beam 40a. As shown in FIG. 1, the handrail rod 63 on the left side of the figure is positioned so that the first bracket 64 faces upward, and the handrail rod 63 on the right side of the figure is positioned so that the first bracket 64 faces downward. In this manner, even if the handrail rods 63 on the right and left sides of the figure, which are the same height, are connected to the central handrail support post 61 from both the left and right sides, the first bracket 64 of the handrail rod 63 on the right side of the figure does not interfere with the first bracket 64 of the handrail rod 63 on the left side of the figure. Therefore, in this embodiment, the handrail rod 63 on the right side of the figure and the handrail rod 63 on the left side of the figure can be installed at the same height.

[0086] 1 and 4, although not described in detail, baseboards 66 are detachably connected to the front and rear ends of the scaffolding board 6, spanning between the lower ends of the handrail posts 61 and the lower ends of each vertical beam 40a, to prevent tools and the like from falling from the scaffolding board 6. Furthermore, the baseboard 66 in this embodiment is formed with a telescopic structure and is extendable and retractable, so that the length of the baseboard 66 can be adjusted according to the distance between the vertical beams 40a, 40a.

[0087] Next, the lifting device will be described in detail. The scaffolding device 1 of this embodiment is equipped with a lifting device that can move the upper structure 5 up and down relative to the lower structure 2. By moving the lower structure 2 up and down using the lifting device, the scaffolding planks 6 can be moved closer to and farther from the underside of the walking floor F, as shown in FIGS. 1 and 2. Therefore, while working on the scaffolding planks 6, as shown in FIG. 1, by lowering the upper structure 5 relative to the lower structure 2 and moving the scaffolding planks 6 away from the underside of the walking floor F, sufficient working space can be secured between the scaffolding planks 6 and the walking floor F, thereby improving the efficiency of maintenance work. On the other hand, while not working on the scaffolding planks 6, by raising the upper structure 5 relative to the lower structure 2 and moving the scaffolding planks 6 closer to the walking floor F, as shown in FIG. 2, sufficient height can be secured from the road below the walking floor F to the scaffolding planks 6, allowing vehicles to pass on the road even when the scaffolding device 1 is installed on the pedestrian bridge A. Therefore, the road can be closed to traffic only during maintenance work and can be reopened during times other than when work is being performed. Therefore, for example, during times of low traffic volume, the upper structure 5 can be lowered relative to the lower structure 2 to perform maintenance work on the scaffolding boards 6, and during times of high traffic volume, the upper structure 5 can be raised relative to the lower structure 2 to reopen the road to traffic, thereby minimizing the inconvenience to road users.

[0088] 9, the lifting device of this embodiment includes a total of four movable pulleys 13 provided at the bottom of four movable columns 50 of the upper structure 5, each of which is disposed close to the inside of the four columns 22 in order to correspond to the four columns 22 in the lower structure 2, a pair of fixed pulleys 14, 14 provided on the upper frame 20 so as to sandwich three columns 22 at three corners of the upper frame 20 of the lower structure 2, a fixed pulley 14 and a fixed metal fitting 19 provided on the upper frame 20 so as to sandwich a column 22 at the remaining corner of the upper frame 20, a rope 15 having one end fixed to the upper frame 20 via the fixed metal fitting 19 and stretched between the fixed pulley 14 and the movable pulley 13, and a winch 16 around which the other end of the rope 15 is wound and which can reel in and reel out the rope 15. Note that in FIGS. 1 and 2, the rope 15 is not shown to make the configuration of the lower structure 2 easier to understand. Furthermore, the structure of the fixing metal fitting 19 is not particularly limited as long as it can fix one end of the rope 15, although this will not be described in detail.

[0089] In the following description, for convenience, the four pillars 22 of the lower structure 2 will be referred to as the first pillar 22A, the second pillar 22B, the third pillar 22C, and the fourth pillar 22D, respectively, and the pillar 22 sandwiched between the fixed pulley 14 and the fixing bracket 19 will be referred to as the first pillar 22A, and the pillars 22B, 22C, and 22D will be referred to in the order of counterclockwise (one direction) in FIG. 9 around the circumferential direction of the upper frame body 20 from the first pillar 22A. Furthermore, the four movable pulleys 13 provided at the bottom of the movable pillars 50 arranged in close proximity to the first pillar 22A, the second pillar 22B, the third pillar 22C, and the fourth pillar 22D will be referred to as the first movable pulley 13A, the second movable pulley 13B, the third movable pulley 13C, and the fourth movable pulley 13D, respectively. In addition, the total of seven fixed pulleys 14 installed on the upper frame body 20 are, in counterclockwise order in Figure 9 from the first support 22A side of the upper frame body 20, the first fixed pulley 14A, the second fixed pulley 14B, the third fixed pulley 14C, the fourth fixed pulley 14D, the fifth fixed pulley 14E, the sixth fixed pulley 14F, and the seventh fixed pulley 14G.

[0090] The winch 16 of this embodiment is attached to an L-shaped frame spanning between the fourth support 22D and the beam 21a of the lower frame 21, and is disposed between the fourth support 22D and the first support 22A. Specifically, the winch 16 is a manual winch including a drum 16a around which the rope 15 is wound and stored, and a handle 16b for rotating the drum 16a. By rotating the drum 16a forward using the handle 16b, the rope 15 can be wound onto the drum 16a, and by rotating the drum 16a in the reverse direction, the rope 15 can be unwound from the drum 16a. Note that the winch 16 may be driven by an electric motor or a hydraulic motor, but a manual winch eliminates the need for a drive source such as a motor, which prevents the winch 16 from becoming heavy and allows the scaffolding device 1 to be made lighter.

[0091] In this embodiment, an eighth fixed pulley 14H is provided on the beam 20a between the first support column 22A and the fourth support column 22D in the upper frame 20, at a position closer to the first support column 22A side.

[0092] As shown in Figure 9, one end of the rope 15 is connected to the upper frame body 20 via a fixing bracket 19, and is wound around the first movable pulley 13A, the first fixed pulley 14A, the second fixed pulley 14B, the second movable pulley 13B, the third fixed pulley 14C, the fourth fixed pulley 14D, the third movable pulley 13C, the fifth fixed pulley 14E, the sixth fixed pulley 14F, the fourth movable pulley 13D, the seventh fixed pulley 14G, and the eighth fixed pulley 14H in that order, and the other end is wound around the drum 16a of the winch 16.

[0093] 9, a rope 15 suspended in a U-shape by a fixed metal fitting 19 and a fixed pulley 14 or a pair of fixed pulleys 14, 14 arranged above each movable pulley 13 so as to sandwich each support strut 22 located close to each movable pulley 13 is hooked to each movable pulley 13, so that the upper structure 5 is suspended by a single rope 15. Therefore, when the winch 16 is rotated forward and the rope 15 is wound up, the length of the rope 15 from the winch 16 to the fixed metal fitting 19 becomes shorter, so that the four movable struts 50 rise in sync, and when the winch 16 is rotated backward and forward and the rope 15 is let out, the length of the rope 15 from the winch 16 to the fixed metal fitting 19 becomes longer, so that the four movable struts 50 descend in sync. Therefore, the upper structure 5 does not tilt forward, backward, left or right during raising and lowering, and the upper structure 5 is always maintained in a horizontal position.

[0094] In addition, in this embodiment, as shown in Figure 9, the rope 15 is wound from the seventh fixed pulley 14G, which is provided close to the fourth support 22D of the beam 20a that is spanned between the first support 22A and the fourth support 22D in the upper frame body 20, through the eighth fixed pulley 14H, which is provided on the first support 22A side of the beam 20a on which the seventh fixed pulley 14G is provided, to a winch 16 arranged on the fourth support 22D side.

[0095] Here, the seventh fixed pulley 14G is subjected to tension between the seventh fixed pulley 14G and the fourth movable pulley 13D of the rope 15, and tension between the seventh fixed pulley 14G and the eighth fixed pulley 14H of the rope 15, but because the eighth fixed pulley 14H is at the same height as the seventh fixed pulley 14G, the direction of the tension between the seventh fixed pulley 14G and the eighth fixed pulley 14H of the rope 15 is perpendicular to the vertical direction. Therefore, the only tension in the rope 15 acting downward on the seventh fixed pulley 14G is the tension between the seventh fixed pulley 14G and the eighth fixed pulley 14H.

[0096] Therefore, by providing the eighth fixed pulley 14H as in this embodiment, the downward force acting on the seventh fixed pulley 14G can be reduced compared to when the rope 15 is directly wound from the seventh fixed pulley 14G to the winch 16, thereby reducing the load on the seventh fixed pulley 14G.

[0097] However, when the winch 16 is disposed on the fourth support column 22D side between the first support column 22A and the fourth support column 22D, even if the rope 15 is looped directly from the seventh fixed pulley 14G to the winch 16, the inclination of the portion of the rope 15 from the seventh fixed pulley 14G to the winch 16 becomes large, and therefore the downward component of the tension of the rope 15 between the seventh fixed pulley 14G and the winch 16 with respect to the seventh fixed pulley 14G becomes small. Therefore, when the winch 16 is disposed on the first support column 22A side between the first support column 22A and the fourth support column 22D, the eighth fixed pulley 14H can be omitted and the rope 15 can be looped directly from the seventh fixed pulley 14G to the winch 16, thereby reducing the load on the seventh fixed pulley 14G.

[0098] Furthermore, if it is acceptable for the load on the seventh fixed pulley 14G to be large, the rope 15 may be looped directly from the seventh fixed pulley 14G to the winch 16, while the winch 16 is positioned on the fourth support 22D side between the first support 22A and the fourth support 22D.

[0099] As described above, the rope 15 is looped around multiple fixed pulleys 14 provided on each beam 20a of the upper frame 20 and the movable pulleys 13 provided on each movable support 50 located on the side of each support 22. Therefore, the rope 15 is stretched along the beam 20a of the upper frame 20 and the movable support 50, except for the section between the winch 16 and the eighth fixed pulley 14H, making it difficult for workers to come into contact with the rope 15. This prevents workers from coming into contact with the rope 15 during the raising and lowering operation of the upper structure 5.

[0100] Furthermore, the winch 16 in this embodiment is attached to an L-shaped frame 17 that spans between the fourth support column 22D at the right rear when looking at the lower structure 2 from the front-to-rear direction and the beam 21a on the right side of the lower frame body 21. Therefore, in this embodiment, the winch 16 is disposed on the right side of the lower structure 2, between the first support column 22A and the fourth support column 22D that are disposed on the right side of the lower structure 2, and nothing is provided to obstruct the rear of the lower structure 2, between the third support column 22C and the fourth support column 22D that are disposed on the rear side, or the front of the lower structure 2, between the first support column 22A and the second support column 22B that are disposed on the front side. Therefore, when workers or ordinary pedestrians pass inside the lower structure 2, the winch 16 or the rope 15 stretched between the winch 16 and the eighth fixed pulley 14H do not obstruct the passage of workers or ordinary pedestrians.

[0101] In this embodiment, the winch 16 is disposed to the right of the lower structure 2, but it may also be disposed to the left, between the left-side supports 22, 22 of the lower structure 2. Even in this case, the winch 16 and the rope 15 do not obstruct the passage of workers or ordinary pedestrians. In this embodiment, the winch 16 is attached to both the support 22 and the beam 21a of the lower frame 21 via the L-shaped frame 17, but the winch 16 may be attached directly to either the support 22 or the lower frame 21 or indirectly via a frame or the like.

[0102] The configuration of the lifting device described above is one example, and is not particularly limited as long as it can move the upper structure 5 up and down relative to the lower structure 2. For example, the lifting device may be a plurality of jacks each attached to the lower end of the movable struts 50 of the upper structure 5. However, if the upper structure 5 is to be moved up and down using a plurality of jacks, the jacks must be driven synchronously to keep the upper structure 5 in a horizontal position. In contrast, with the lifting device of this embodiment, all four movable struts 50 can be moved up and down synchronously with a single rope 15, making it easy to maintain the upper structure 5 in a horizontal position. However, if it is not necessary to move the upper structure 5 up and down relative to the lower structure 2, the scaffolding system 1 does not need to be equipped with a lifting device.

[0103] Next, a method for assembling the scaffolding device 1 of this embodiment will be described in detail. First, a scaffolding plank support unit U is assembled on the ground by assembling the upper structure 5 to the lower structure 2. Next, as shown in FIG. 10 , the scaffolding plank support unit U is lifted by a crane H, and the lower structure 2 is placed on the walking floor F. More specifically, a four-strand chain sling C is attached to a hook Ha attached to the tip of the crane's boom, and the hook portions (not shown) attached to the tip of the chain sling C are hooked onto the rings 22a attached to the upper ends of the pillars 22 of the lower structure 2, respectively, thereby lifting the scaffolding plank support unit U with the crane H. Then, as shown in FIG. 10 , the scaffolding plank support unit U is carried to a location where the lower structure 2 is positioned above the walking floor F and the pair of hanging members 4, 4 are positioned above the outer sides of the parapets P, P, and the scaffolding plank support unit U is then lowered directly below from that state, thereby placing the lower structure 2 on the walking floor F. In addition, a sling other than the chain sling C may be attached to the hook Ha of the crane H to lift the scaffolding board support unit U.

[0104] As described above, in the scaffolding device 1 of this embodiment, the lower structure 2 is formed in a box shape by connecting the corners of the upper frame 20 and the lower frame 21 with four supports 22, and by reducing the thickness of the supports 22 and the beams 20a, 21a of the upper frame 20 and the lower frame 21 that make up the lower structure 2, it is possible to reduce the weight of the lower structure 2 without reducing the strength of the lower structure 2. In this way, in this embodiment, the weight of the lower structure 2 can be reduced, and the weight of the scaffolding board support unit U including the lower structure 2 can also be reduced, making it easier to lift the scaffolding board support unit U with the crane H and install it on the walking floor F of the pedestrian bridge A.

[0105] Finally, the aerial work platform is placed on the road provided below the walking floor F of the footbridge A, and a worker suspends the scaffolding board 6 between the lower ends of the hanging members 4, 4 on the working platform of the aerial work platform, which has been raised up to near the space between the hanging members 4, 4 of the scaffolding board support unit U installed on the walking floor F, thereby assembling the scaffolding device 1. The handrail support posts 61, handrail rods 63 and baseboards 66 installed on the scaffolding board 6 can be assembled by a worker on the scaffolding board 6, but they may also be assembled on the working platform of the aerial work platform.

[0106] According to this assembly method, the scaffolding board support unit U consisting of the lower structure 2 and upper structure 5, which have been pre-assembled on the ground, is placed on the walking floor F by the crane H, and then the scaffolding board 6 is hung between the lower ends of the hanging members 4, 4 on the work platform of the aerial work vehicle to assemble the scaffolding device 1, so there is almost no need to perform assembly work for the scaffolding device 1 on the walking floor F. This makes it possible to significantly reduce the work time on the walking floor F required to install the scaffolding device 1. Therefore, the time that the footbridge A is closed to traffic during the installation work of the scaffolding device 1 can also be shortened, minimizing the inconvenience to users of the footbridge A.

[0107] Furthermore, when assembling all the components of the scaffolding device 1 on the walking floor F, the worker must lean out from the outside of the walking floor F to attach the hanging members 4 to the support frame 3, and the worker must work on the hanging members 4, which are positioned outside the walking floor F, to suspend the scaffolding plank 6 between the lower ends of the hanging members 4, 4. In contrast, with the above assembly method, the scaffolding plank support unit U, consisting of the lower structure 2 and upper structure 5 pre-assembled on the ground, is installed on the walking floor F by crane H, so the worker does not need to lean out from the outside of the walking floor F to attach the hanging members 4. In addition, the work of suspending the scaffolding plank 6 between the lower ends of the hanging members 4, 4 can also be performed on the safe work platform of an aerial work platform. Therefore, the above assembly method ensures extremely safe assembly work of the scaffolding device 1.

[0108] Instead of using an aerial work vehicle, a temporary scaffold can be assembled on the road below the walking floor F, and the scaffolding board 6 can be hung between the lower ends of the hanging members 4, 4 on the temporary scaffold. However, when using a temporary scaffold, it takes time and effort to assemble and dismantle the temporary scaffold, but when using an aerial work vehicle, it is preferable because work can be prepared and taken down simply by moving the aerial work vehicle.

[0109] The method of assembling the scaffolding device 1 is not limited to the above-described method, and the scaffolding device 1 may be assembled by other methods.

[0110] As described above, the scaffolding device 1 of this embodiment is used for the maintenance of a pedestrian bridge A and comprises a lower structure 2 that can be installed on the walking floor F of the pedestrian bridge A, a support frame 3 that is attached to the lower structure 2 and extends above the lower structure 2 in a horizontal direction that intersects the extension direction of the walking floor F of the pedestrian bridge A and protrudes laterally beyond the parapets P on both sides of the pedestrian bridge A, and an upper structure 5 that has a pair of hanging members 4 that extend downward from each part of the support frame 3 that protrudes outward from the parapets P, with their lower ends facing each other laterally, and a scaffolding board 6 that is detachably spanned between the lower ends of the hanging members 4,4 and faces the underside of the walking floor F, and the lower structure 2 includes an upper frame body 20 and a lower frame body 21 that are rectangular and arranged so as to face each other vertically, and four supports 22 that extend in the vertical direction and connect the corners of the upper frame body 20 and the lower frame body 21.

[0111] According to the scaffolding device 1 configured in this manner, the lower structure 2 is not a gate-type as in the past, but is formed into a box-like shape by connecting the corners of the upper frame body 20 and the lower frame body 21 with four supports 22, thereby improving the strength of the lower structure 2. Therefore, even if the thickness of the supports 22 and the beams 20a, 21a of the upper frame body 20 and the lower frame body 21 that make up the lower structure 2 is reduced, the strength of the lower structure 2 can be sufficiently ensured, so the weight of the scaffolding device 1 can be reduced without reducing the strength. Reducing the weight of the scaffolding device 1 in this way makes it easier to move and transport the scaffolding device 1 and also makes it easier to assemble the lower structure 2.

[0112] In this embodiment, the lower structure 2 is composed of an upper frame body 20, a lower frame body 21, and four pillars 22 connecting the corners of the upper frame body 20 and the lower frame body 21, but auxiliary pillars may be hung between the upper frame body 20 and the lower frame body 21 for reinforcement.

[0113] The scaffolding device 1 of this embodiment is also equipped with a lifting device that can move the upper structure 5 up and down relative to the lower structure 2, and the upper structure 5 has four movable struts 50 that are respectively arranged on the sides of the supports 22 and can be connected to the supports 22, and whose upper ends are connected to the lower part of the support frame 3, and the lifting device is equipped with movable pulleys 13 that are respectively provided on the movable struts 50, and a pair of fixed pulleys 14, 14 that are provided on the upper frame body 20 so as to sandwich the supports 22 at the three corners of the upper frame body 20, The structure comprises a fixed pulley 14 and a fixed bracket 19 provided on the upper frame 20 so as to sandwich the support 22 at the remaining corner, a rope 15 having one end fixed to the upper frame 20 via the fixed bracket 19 and wound around the fixed pulley 14 and the movable pulley 13, and a winch 16 around which the other end of the rope 15 is wound and which can wind and unwind the rope 15; when the rope 15 is wound by the winch 16, the four movable supports 50 rise in sync, and when the rope 15 is unwound by the winch 16, the four movable supports 50 descend in sync.

[0114] According to the scaffolding device 1 configured in this manner, the four movable columns 50 are suspended by a single rope 15, and when the winch 16 is rotated, the four movable columns 50 are raised and lowered in sync, so that the upper structure 5 can always be maintained in a horizontal position. Therefore, there is no need to adjust the inclination of the upper structure 5 so that it is in a horizontal position every time the upper structure 5 is raised or lowered relative to the lower structure 2, which makes it easier to raise and lower the upper structure 5.

[0115] Furthermore, with the scaffolding device 1 configured in this manner, the ropes 15 are looped around a plurality of fixed pulleys 14 provided on each beam 20a of the upper frame 20 and movable pulleys 13 provided on each movable support 50 arranged on the side of each support 22. Therefore, the ropes 15 are stretched along the beams 20a of the upper frame 20 and the movable support 50, except for the portion between the winch 16 and the fixed pulleys 14, making it difficult for workers and ordinary pedestrians to come into contact with the ropes 15. This prevents workers from coming into contact with the ropes 15 while the upper structure 5 is being raised or lowered.

[0116] The configuration of the lifting device described above is an example, and is not particularly limited as long as it allows the upper structure 5 to move up and down relative to the lower structure 2. Furthermore, if it is not necessary to move the upper structure 5 up and down relative to the lower structure 2, the scaffolding device 1 does not need to be equipped with a lifting device.

[0117] Moreover, in the scaffolding device 1 of this embodiment, the winch 16 is manually operated. According to the scaffolding device 1 configured in this manner, the winch 16 does not have a drive source such as a motor, so it is possible to prevent the winch 16 from becoming heavy, thereby reducing the weight of the scaffolding device 1. However, the winch 16 may also be rotationally driven by an electric motor or a hydraulic motor.

[0118] The scaffolding device 1 of this embodiment is also provided with a lifting device that can move the upper structure 5 up and down relative to the lower structure 2, and the upper structure 5 has four movable struts 50 that are respectively arranged on the sides of the supports 22 and can be connected to the supports 22 via connecting fittings 51, and whose upper ends are connected to the lower part of the support frame 3, and the connecting fittings 51 each have a fixed part 52 that is fixed to the outer periphery of the movable strut 50, an opposing part 53 that is connected to the fixed part 52 and faces the outer periphery of the support 22, and a pin hole 22b that is held by the opposing part 53 and is arranged at predetermined intervals along the axial direction of the support 22. The fixing device 55 has a case 57 into which the fixing pin 56 is inserted so as to be movable in the axial direction, a coil spring 58 that urges the fixing pin 56 toward the support 22, and a stopper 59 that abuts against a regulating piece 57e provided on the outer periphery of the case 57 to regulate the movement of the fixing pin 56 toward the support 22, and the stopper 59 has a cam piece 59a that can switch the position of the fixing pin 56 between a pushed-in position where it can be inserted into the pin hole 22b and a pulled-out position where it is separated from the support 22, depending on the abutment position with the regulating piece 57e.

[0119] In the scaffolding device 1 configured in this manner, the position of the fixing pin 56 can be switched between the pushed-in position and the pulled-out position simply by changing the abutment position of the cam piece 59a with respect to the restricting piece 57e, so that the movable support 50 can be easily attached to and detached from the support 22. When the fixing pin 56 is in the pulled-out position and removed from the pin hole 22b of the support 22, the movable support 50 is released from connection with the support 22, so that the upper structure 5 can be moved up and down by the lifting device. On the other hand, when the fixing pin 56 is in the pushed-in position and inserted into the pin hole 22b of the support 22, the movable support 50 is connected to the support 22 and the up and down movement of the upper structure 5 is restricted, so that accidents such as the upper structure 5 moving up and down while the scaffolding device 1 is in use can be prevented.

[0120] Furthermore, in the scaffolding device 1 configured in this manner, the fixing device 55 is integrated with the connecting fitting 51, so that the fixing pin 56 can be prevented from falling to the ground or being lost.

[0121] In addition, in this embodiment, the cam piece 59a is rotatably connected to the fixed pin 56 with the radial direction of the fixed pin 56 as the rotation axis, faces the anti-pillar side of the regulating piece 57e, and has a first abutment portion 59a1 and a second abutment portion 59a2 that are at different distances from the rotation axis and can abut against the regulating piece 57e.

[0122] With the cam piece 59a configured in this manner, the axial position of the fixing pin 56 can be displaced by the difference between the distance between the first contact portion 59a1 of the cam piece 59a and the rotation shaft and the distance between the second contact portion 59a2 of the cam piece 59a and the rotation shaft, depending on whether the first contact portion 59a1 or the second contact portion 59a2 is brought into contact with the restriction piece 57e. Therefore, the position of the fixing pin 56 can be easily switched between the pushed-in position and the pulled-out position simply by rotating the stopper 59, making it easier to attach and detach the movable support column 50 to and from the support column 22. Note that the above-described configuration of the cam piece 59a is one example, and the cam piece 59a is not particularly limited as long as the position of the fixing pin 56 can be switched between the pushed-in position where it can be inserted into the pin hole 22b and the pulled-out position where it is separated from the support column 22, depending on the contact position with the restriction piece 57e.

[0123] In the scaffolding device 1 of this embodiment, as shown in FIG. 3 , the lower structure 2 includes a floor 9 installed on the lower frame 21, and slopes 10 installed between the front and rear ends of the floor 9 and the walking floor F of the footbridge A, as viewed from the extension direction of the walking floor F. With the scaffolding device 1 configured in this manner, workers and general pedestrians can walk on the slopes 10 and the floor 9 to pass inside the lower structure 2. Therefore, even if the lower frame 21 is connected to the bottom of each support 22 to form a box-like structure, workers and general pedestrians do not risk tripping over the lower frame 21. Furthermore, because the floor 9 and slopes 10 prevent steps, even wheeled vehicles such as wheelchairs and strollers can easily pass inside the lower structure 2. The slopes 10 are not shown in FIGS. 1 and 2 .

[0124] However, the slope 10 may be omitted if it is acceptable to have a step between the walking floor F and the floor material 9. Also, if the vehicle passes inside the lower structure 2 while straddling the front and rear beams 21a, 21a of the lower frame 21, the floor material 9 may also be omitted.

[0125] Furthermore, in the scaffolding device 1 of the present embodiment, each portion of the support frame 3 that protrudes outward from the parapets P, P is provided with a plurality of mounting holes 30b1 that are arranged side by side in the horizontal direction and that can be used to attach the upper ends of the hanging members 4. With the scaffolding device 1 configured in this manner, the mounting holes 30b1 that serve as mounting portions are arranged side by side in the horizontal direction in each portion of the support frame 3 that protrudes outward from the parapets P, P, so that the mounting position of the hanging member 4 relative to the support frame 3 can be adjusted by selecting which mounting hole 30b1 to attach the upper end of the hanging member 4 to. Therefore, the width between the left and right hanging members 4, 4 can be changed as needed to match the horizontal width of the footbridge A that is the target of maintenance.

[0126] The mounting portions provided on each portion of the support frame 3 that protrudes outward from the parapets P, P are not particularly limited as long as they can selectively mount the upper ends of the hanging members 4. However, if there is no need to adjust the width between the hanging members 4, 4, the hanging members 4 may be integrally connected to the support frame 3 by welding or the like.

[0127] In addition, the assembly method of the scaffolding device 1 of this embodiment includes a step of assembling a scaffolding board support unit U on the ground by assembling an upper structure 5 to a lower structure 2, a step of lifting the scaffolding board support unit U with a crane H and installing the lower structure 2 on a walking floor F, and a step of suspending a scaffolding board 6 between the lower ends of the hanging members 4, 4 from above an aerial work vehicle or temporary scaffolding placed on the ground.

[0128] According to the method for assembling the scaffolding device 1 configured in this manner, the scaffolding board support unit U consisting of the lower structure 2 and upper structure 5 pre-assembled on the ground is installed on the walking floor F by the crane H, so the work time on the walking floor F required to install the scaffolding device 1 can be significantly reduced compared to assembling all of the parts of the scaffolding device 1 on the walking floor F of the pedestrian bridge A. Therefore, the time that the pedestrian bridge A is closed to traffic during the installation work of the scaffolding device 1 can also be shortened, minimizing the inconvenience to users of the pedestrian bridge A.

[0129] Furthermore, when assembling all the components of the scaffolding device 1 on the walking floor F, the worker must lean outward from the walking floor F to attach the hanging members 4 to the support frame 3, and the worker must work on the hanging members 4, which are positioned outside the walking floor F, to suspend the scaffolding plank 6 between the lower ends of the hanging members 4, 4. In contrast, with the above-described assembly method, the scaffolding plank support unit U, consisting of the lower structure 2 and upper structure 5 pre-assembled on the ground, is installed on the walking floor F by crane H, so the worker does not need to lean outward from the walking floor F to attach the hanging members 4. Furthermore, the work of suspending the scaffolding plank 6 between the lower ends of the hanging members 4, 4 can also be performed on a safe work platform of an aerial work platform or temporary scaffold. Therefore, the above-described assembly method ensures extremely safe assembly of the scaffolding device 1.

[0130] Furthermore, in this embodiment, as described above, the lower structure 2 can be made lighter, and the scaffolding board support unit U including the lower structure 2 can also be made lighter, making it easier to lift the scaffolding board support unit U with a crane H and install it on the walking floor F of the pedestrian bridge A.

[0131] However, the method of assembling the scaffolding device 1 is not limited to the above-mentioned assembly method, and the scaffolding device 1 may be assembled by other assembly methods.

[0132] Although the preferred embodiment of the present invention has been described in detail above, modifications, variations and changes can be made without departing from the scope of the appended claims. [Explanation of symbols]

[0133] 1 Scaffolding device, 2 Lower structure, 3 Support frame, 4 Hanging member, 5 Upper structure, 6 Scaffolding board, 9 Floor material, 10 Slope, 13 Movable pulley, 14 Fixed pulley, 15 Cable, 16 Winch, 19 Fixing bracket, 20 Upper frame, 21 Lower frame, 22 Support, 22b Pin hole, 30b1... Mounting hole (mounting portion), 50... Movable support, 51... Connecting fitting, 53... Opposing portion, 55... Fixing device, 56... Fixing pin, 57... Case, 57e... Restricting piece, 58... Coil spring, 59... Cam piece, A... Footbridge, F... Walking floor, H... Crane, P... Parapet, U... Scaffolding board support unit

Claims

1. A scaffolding device used for the maintenance of a pedestrian bridge, A substructure that can be installed on the walking floor of the pedestrian bridge; an upper structure having a support frame attached to the lower structure, extending above the lower structure in a lateral direction intersecting the extension direction of the walking floor of the footbridge and protruding in the lateral direction beyond the parapets on both sides of the footbridge, and a pair of hanging members extending downward from each portion of the support frame protruding outward from the parapets with their lower ends facing each other in the lateral direction; a scaffolding board that is detachably spanned between the lower ends of the hanging members and faces the underside of the walking floor; The lower structure includes: an upper frame body and a lower frame body, each having a rectangular shape and arranged to face each other vertically; Four support columns extending in the vertical direction and connecting the corners of the upper frame and the lower frame, respectively. A scaffolding device characterized by:

2. a lifting device that can move the upper structure up and down relative to the lower structure; the upper structure has four movable columns that are respectively arranged on the sides of the support columns and are connectable to the support columns, and whose upper ends are connected to the lower part of the support frame; The lifting device is A movable pulley is provided on each of the movable columns; a pair of fixed pulleys provided on the upper frame so as to sandwich the support posts at the three corners of the upper frame, and a fixed pulley and a fixing bracket provided on the upper frame so as to sandwich the support post at the remaining corner; a rope having one end fixed to the upper frame body via the fixing metal fitting and wound around the fixed pulley and the movable pulley; a winch around which the other end of the rope is wound and which is capable of winding and unwinding the rope, When the winch winds up the rope, the four movable columns rise in unison, and when the winch unleashes the rope, the four movable columns descend in unison. Scaffolding apparatus according to claim 1 .

3. a lifting device that can move the upper structure up and down relative to the lower structure; the upper structure has four movable columns that are respectively arranged on the sides of the support columns, are connectable to the support columns via connecting metal fittings, and have upper ends connected to the lower part of the support frame; The connecting fitting has a fixing portion fixed to the outer periphery of the movable support column, an opposing portion connected to the fixing portion and opposing the outer periphery of the support column, and a fixing device having a fixing pin held by the opposing portion and removable from any of a plurality of pin holes arranged at predetermined intervals along the axial direction of the support column, the fixing device includes a case into which the fixing pin is inserted so as to be movable in the axial direction, a coil spring that biases the fixing pin toward the support pillar, and a stopper that abuts against a restricting piece provided on the outer periphery of the case to restrict movement of the fixing pin toward the support pillar, The stopper has a cam piece that can switch the position of the fixing pin between a push-in position where the fixing pin can be inserted into the pin hole and a pull-out position where the fixing pin is separated from the support pillar, depending on the abutment position with the restricting piece. Scaffolding apparatus according to claim 1 .

4. The winch is manually operated Scaffolding device according to claim 2 .

5. The lower structure has a floor material installed on the lower frame body, and slopes installed between the front and rear ends of the floor material and the walking floor when viewed from the extension direction of the walking floor of the pedestrian bridge. Scaffolding apparatus according to claim 1 .

6. Each portion of the support frame that protrudes outward from the balustrade is provided with a plurality of mounting portions that are arranged in a line along the horizontal direction and to which the upper ends of the hanging members can be attached. Scaffolding apparatus according to claim 1 .

7. A method for assembling a scaffolding device according to claim 1, comprising: a step of assembling the scaffolding board support unit on the ground by assembling the upper structure to the lower structure; lifting the scaffold plank support unit with a crane and placing the substructure on the walking floor; and a step of suspending the scaffolding board between the lower ends of the hanging members from above an elevated work platform or temporary scaffolding placed on the ground. A method for assembling a scaffolding device.

Images