Suspended scaffolding

Abstract

The present invention aims to provide a solution that avoids the troublesome task of raising the frame every time a large vehicle or ship passes by, while also ensuring sufficient working space between the frame and the underside of the structure. [Solution] The present invention comprises a frame 10 formed by connecting the ends of a plurality of beam members 1 having upper chord members 1a and lower chord members 1b arranged in a vertical line, a chain 2 for suspending the frame 10, and a floor structure 3 having a floor plate 30 connected to the frame 10 and positioned inside the frame 10 and at least below the upper end of the upper chord member 1a, wherein the lower end of the floor structure 3 is positioned at a height at least equal to or greater than the lower end of the lower chord member 1b.

Description

Technical Field

[0006] , ,

[0005] ,

[0001] The present invention relates to a suspended scaffold.

Background Art

[0002] As a conventional suspended scaffold, there is one that includes a frame formed by connecting the ends of four beam members, and a floor board spanned between the beam members facing each other in the frame, and is attached to the frame at the lower end of a suspension member such as a chain whose upper end is connected to a structure such as a building or a construction, and is suspended and supported by the structure and used for maintenance work of the structure (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When using such a suspended scaffold, for example, under a structure where ships or vehicles pass, such as a bridge spanning a river or sea or a pedestrian bridge straddling a road, if there is an obstacle to the passage of ships or the like below the suspended scaffold, in order to ensure a space that allows the passage of ships or the like below the frame so as not to interfere with the passage of ships, it is necessary to raise the frame.

[0005] However, when the frame is raised, the distance between the floor board installed on the frame and the lower surface of the structure is shortened accordingly, so there is a risk that a sufficient working space for the operator to perform maintenance work on the lower surface of the structure cannot be secured.

[0006] Another possible method for maintenance work is to position the frame below the suspended scaffolding so that ships and vehicles can pass underneath, and only raise the frame when large vehicles or ships that would interfere with the suspended scaffolding pass by. However, this method would require raising the frame every time a large vehicle or ship passes, which would be extremely cumbersome.

[0007] Therefore, the present invention aims to provide a suspended scaffold that can avoid the troublesome task of raising the frame every time a large vehicle or ship passes by, and can secure sufficient working space between the floorboard and the underside of the structure. [Means for solving the problem]

[0008] To solve the aforementioned problems, the suspended scaffolding of the present invention comprises a frame formed by connecting the ends of a plurality of beam members having upper chords and lower chords arranged vertically, a suspension member for suspending the frame, and a floor structure having a floor plate connected to the frame and positioned inside the frame and at least below the upper end of the upper chord, wherein the lower end of the floor structure is positioned at a height at least equal to or greater than the lower end of the lower chord. With this configuration, the position of the floor plate can be lowered without lowering the position of the lower end of the suspended scaffolding, so the height of the lower end of the suspended scaffolding does not change even if the position of the floor plate is lowered. Therefore, even if the position of the frame is raised to a level where large vehicles or ships can pass underneath the suspended scaffolding, sufficient working space can be secured between the floor plate and the underside of the structure. Furthermore, there is no need to raise the frame every time a large vehicle or ship passes by.

[0009] Furthermore, in the suspended scaffolding of the present invention, the floor structure may have at least one or more first support members, each having a first support portion that spans between opposing beam members and supports a floorboard. With this configuration, the height position of the floorboard can be set by the height position of the first support portion. Moreover, the load-bearing strength of the suspended scaffolding can be arbitrarily set by increasing or decreasing the number of first support portions that support the floorboard.

[0010] Furthermore, in the suspended scaffolding of the present invention, the lower end of the floor structure may be aligned horizontally with the lower end of the lower chord member. With this configuration, the position of the floorboard can be lowered to the maximum extent possible without changing the height from the lower end of the suspended scaffolding to the road or the water surface such as a river or the sea. Therefore, the working space between the underside of the structure and the floorboard can be made as wide as possible without changing the height from the lower end of the suspended scaffolding to the road or the water surface such as a river or the sea.

[0011] Furthermore, in the suspended scaffolding of the present invention, the first support member may have a first support portion extending horizontally and first attachment portions extending upward from each end of the first support portion, with their upper ends detachably connected to the upper chord member. With this configuration, since the first attachment portions are connected to the upper chord member, even if the first support portion is positioned below the upper chord member, workers can safely span the first support member between opposing beam members without leaning out.

[0012] Furthermore, in the suspended scaffolding of the present invention, the frame is formed in a rectangular shape in plan view by having four joints that connect the ends of four beam members, and the beam member over which the first support member in the frame is spanned is designated as one-side beam member, and the remaining beam members are designated as other-side beam members, and the floor structure has a second support member positioned parallel to the first support member between the first support member and the other-side beam member, and the second support member may have a second support part that extends along the horizontal direction and is positioned at the same height as the first support part to support the floorboard, and a second attachment part provided at the end of the second support part and detachably connected to the joint. With this configuration, in addition to the first support member spanned between the one-side beam members, a second support member that supports the floorboard can be positioned close to the other-side beam member inside the frame using the joint, thereby increasing the load capacity of the floorboard.

[0013] Furthermore, in the suspended scaffolding of the present invention, the floor structure has a baseboard that rises from the outer edge of the floorboard, and the baseboard may have a lateral closing plate portion that rises from the outer edge of the floorboard and closes the gap between the upper chord and the lower chord of the beam member, and an upper closing plate portion provided at the upper end of the lateral closing plate portion and closes the gap between the floorboard and the beam member. With this configuration, the gap between the upper chord and the lower chord of the beam member and the gap between the floorboard and the beam member are closed by the baseboard, so that tools and the like can not fall through these gaps.

[0014] Furthermore, the suspended scaffold of the present invention is equipped with a locking device provided at the first mounting portion that can fix the first mounting portion in a state where it is connected to the upper chord member. The first mounting portion has an upright portion extending upward from the end of the first support portion, a projection portion that protrudes from the upright portion toward the beam member and abuts against the upper surface of the upper chord member, and a pin that protrudes from the lower end of the projection portion and is inserted from above into a hole provided in the upper chord member. The locking device has a locking piece arranged parallel to the projection portion and movable parallel to the projection portion, which together with the projection portion can sandwich at least a portion of the upper chord member and face that portion, and a fixing means that can fix the locking piece to the upright portion so that it cannot move. The locking piece may be movable between a position that sandwiches a portion of the upper chord member together with the projection portion and a position that does not face a portion of the upper chord member in the vertical direction. With this configuration, the locking device is composed only of a locking piece and a fixing means, so the number of parts is reduced. Furthermore, since the first support member can be carried with the locking piece and fixing means still attached to the first mounting part, there is no need to attach the locking device to the first support member when connecting the first support member to the beam member.

[0015] Furthermore, the suspended scaffolding of the present invention may also include a support beam that is detachably spanned between the upper chords of opposing beam members and positioned above the floorboard, and a raised floor installed on the support beam. With this configuration, even when the floorboard is installed below the upper chords of the beam members, the raised floor can be detachably installed above the floorboard, so that workers can use the raised floor as scaffolding to perform maintenance work on high-positioned parts of the structure.

[0016] Furthermore, in the suspended scaffolding of the present invention, the frame is formed in a rectangular shape in plan view by connecting the ends of four beam members, and each first attachment portion of the first support member is connected to the upper chord of beam members that are opposite each other in one direction in the frame, and the support beam may be spanned between the upper chords of beam members that are opposite each other in a direction perpendicular to one direction in the frame. With this configuration, since the first support member and the support beam are spanned between other beam members, it is possible to prevent assembly errors such as connecting the first support member where the support beam should be connected.

[0017] Furthermore, the suspended scaffolding of the present invention includes a plurality of baseboards arranged in a line along the inner circumference of the frame to close the gap between the upper chord and lower chord members of the beam members, and recesses may be formed at the upper ends of the baseboards at positions corresponding to the parts on the upper chord members of the beam members to which the ends of the support beams are connected. With this configuration, the recesses prevent the support beams from interfering with the second baseboard, so that even if baseboards are installed on the inner circumference side of the frame, the support beams can be spanned between the beam members. [Effects of the Invention]

[0018] The suspended scaffolding of the present invention avoids the troublesome task of raising the frame every time a large vehicle or ship passes by, and also ensures sufficient working space between the floorboard and the underside of the structure. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 is a front view of a suspended scaffolding being used as part of a bridge structure, with the beam members positioned on the front side of the suspended scaffolding cut out to show their positions. [Figure 2] Figure 2 is a plan view of the suspended scaffolding. [Figure 3] Figure 3 is a view taken along arrow AA in Figure 2. [Figure 4] Figure 4 is a side view of a beam member in a suspended scaffold. [Figure 5] Figure 5 is a front view of a beam member in a suspended scaffold. [Figure 6]FIG. 6 is a side view showing an enlarged part of a beam member in the suspension scaffold. [Figure 7] FIG. 7 is a perspective view of a joint in the suspension scaffold. [Figure 8] FIG. 8 is a side view showing an enlarged part where the beam member and the joint are connected in the suspension scaffold. [Figure 9] FIG. 9 is an enlarged perspective view showing a state where a chain as a suspension member is fixed to the joint. [Figure 10] FIG. 10 is a plan view showing a state where only the first support member and the second support member are installed on the frame body in the suspension scaffold. [Figure 11] FIG. 11(A) is a side view showing an enlarged connection part between the first support member and the beam member. FIG. 11(B) is a cross-sectional view taken along the line X-X of FIG. 11(A). [Figure 12] FIG. 12(A) is a side view of the second support member. FIG. 12(B) is a plan view of the second support member. [Figure 13] FIG. 13 is a view showing an enlarged connection part between the second support member and the joint. [Figure 14] FIG. 14 is a view taken along the arrow B-B in FIG. 2. [Figure 15] FIG. 15 is a view taken along the arrow C-C in FIG. 2. [Figure 16] FIG. 16 is a view taken along the arrow D-D in FIG. 15. [Figure 17] FIG. 17 is a perspective view of the second ledger. [Figure 18] FIG. 18 is a plan view of the suspension scaffold in a state where a support beam and a raised bottom floor are installed on the frame body. [Figure 19] FIG. 19 is a view taken along the arrow E-E in FIG. 18.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, the suspension scaffold of the present invention will be described with reference to the drawings. The same reference numerals attached through several drawings indicate the same components.

[0021] As shown in Figure 1, the suspended scaffolding F of this embodiment is suspended from a bridge 11, which is a structure comprising a main girder 11a spanning between abutments and piers (not shown), and a deck slab 11b supported by the main girder 11a, providing workers with a work platform usable for maintenance work. Furthermore, in the suspended scaffolding F of this embodiment, since only the deck slab 30 can be lowered without changing the position of the lower end of the suspended scaffolding F, as shown in Figure 1, even when the suspended scaffolding F is installed in a position facing the main girder 11a and it is difficult to secure a working space between the main girder 11a and the deck slab 30, it is possible to secure a working space while also securing space below the suspended scaffolding F to allow passage of ships, etc.

[0022] Specifically, as shown in Figures 1, 2, 3, and 4, the suspended scaffolding F of this embodiment comprises a frame 10 formed by connecting the ends of a plurality of beam members 1 having upper chord members 1a and lower chord members 1b arranged vertically, a chain 2 as a suspension member for suspending the frame 10, and a floor structure 3 having a floor plate 30 connected to the frame 10 and positioned inside the frame 10 and at least below the upper end of the upper chord member 1a, with the lower end of the floor structure 3 positioned at a height at least equal to or greater than the lower end of the lower chord member 1b.

[0023] In this embodiment, the suspended scaffolding F is positioned below the main girder 11a of the bridge 11, with the upper end of the chain 2 connected to the deck slab 11b of the bridge 11, as shown in Figure 1. Furthermore, other suspended scaffoldings F1 are connected to the left and right sides of the suspended scaffolding F in Figure 1, each equipped with a floor plate positioned at the same height as the upper end of the upper chord member 1a of the beam member 10 that constitutes the frame 10 of the suspended scaffolding F. Although not shown, by connecting the suspended scaffolding F or the other suspended scaffoldings F1 in the left-right and depth directions in Figure 1, the total floor area of ​​the suspended scaffoldings F and F1 can be expanded to any size. Note that in Figure 1, the beam member positioned on the front side of the suspended scaffolding F is cut out to make the height of the floor plate 30 of the suspended scaffolding F easier to understand. Furthermore, the structures on which the suspended scaffolding F is used are not limited to bridges 11, but may also be structures such as pedestrian bridges or buildings.

[0024] The following describes in detail each part of the suspended scaffolding F. As shown in Figure 2, the frame 10 is formed in a rectangular shape in plan view, having four beam members 1 and four joints 4 that connect the ends of each beam member 1.

[0025] As shown in Figure 4, the beam member 1 comprises an upper chord member 1a and a lower chord member 1b arranged parallel to each other vertically, and a plurality of diagonal members 1c that are placed diagonally between the upper chord member 1a and the lower chord member 1b to connect them, thus forming a truss structure. In addition, both ends of the upper chord member 1a and the lower chord member 1b are provided with connecting parts 1e that can be connected to a joint 4.

[0026] As shown in Figure 5, the upper chord member 1a comprises a pair of upper support pieces 1a1, 1a1 with an L-shaped cross-section, extending along the longitudinal direction of the beam member 1. Specifically, each upper support piece 1a1 is formed in an L-shape with a bottom portion 1a2 extending along the longitudinal direction of the beam member 1 and a vertical portion 1a3 projecting vertically upward from the inner end of the bottom portion 1a2. The vertical portions 1a3 are positioned facing each other, with the bottom portions 1a2 projecting outward from each other. Furthermore, as shown in Figure 2, each bottom portion 1a2 of the upper chord member 1a has three holes 1a4: one in the center in the longitudinal direction, one between the center and one end, and one between the center and the other end.

[0027] As shown in Figure 5, the lower chord member 1b comprises a pair of lower support pieces 1b1, 1b1 with an L-shaped cross-section, extending along the longitudinal direction of the beam member 1. Specifically, each lower support piece 1b1 is formed in an L-shape with a bottom portion 1b2 extending along the longitudinal direction of the beam member 1 and a vertical portion 1b3 projecting vertically downward from the inner end of the bottom portion 1b2. The vertical portions 1b3 are positioned facing each other, with the bottom portions 1b2 projecting outward from each other.

[0028] The upper chord member 1a and the lower chord member 1b, configured in this way, are connected by multiple diagonal members 1c. Specifically, the upper end of each diagonal member 1c is welded while inserted between the upper support pieces 1a1, 1a1, and the lower end of each diagonal member 1c is welded while inserted between the lower support pieces 1b1, 1b1, thereby connecting the upper chord member 1a and the lower chord member 1b.

[0029] As shown in Figure 6, the connecting section 1e includes a rectangular tubular connecting member 1e1 whose upper and lower ends are inserted between the upper support pieces 1a1, 1a1 and between the lower support pieces 1b1, 1b1, respectively, on both sides in the longitudinal direction of the beam member 1, and is spanned and connected between the upper chord member 1a and the lower chord member 1b, and a pair of upper and lower connecting pieces 1e2, 1e2 that extend from the upper and lower ends of the connecting member 1e1 along the longitudinal direction of the beam member 1 and protrude outward from one end of the upper chord member 1a and the lower chord member 1b. Each connecting piece 1e2 is provided with a first mounting hole 1e2a located at the tip and a second mounting hole 1e2b located at the base, separated by a predetermined interval, and the first mounting holes 1e2a, 1e2a and the second mounting holes 1e2b, 1e2b face each other. Note that in Figure 6, the thickness of the connecting piece 1e2 is thin, making it difficult to show the first mounting hole 1e2a and the second mounting hole 1e2b with dashed lines, so they are shown with solid lines.

[0030] Furthermore, the connecting section 1e is positioned between the connecting pieces 1e2, 1e2 and includes a pair of upper and lower flat support pieces 1e3, 1e3 that extend from the connecting member 1e1 along the longitudinal direction of the beam member 1 and face the connecting pieces 1e2, 1e2 from above and below. The support piece 1e3 is provided with a first insertion hole 1e3a facing the first mounting hole 1e2a and a second insertion hole 1e3b facing the second mounting hole 1e2b. The connecting section 1e also includes a cylindrical connecting pipe 1e4 that is supported at each end by the support piece 1e3 and spans between the pair of support pieces 1e3, 1e3. Both ends of the connecting pipe 1e4 face the first insertion hole 1e3a, and the inside of the connecting pipe 1e4 is in communication with the first insertion hole 1e3a. Note that in Figure 6, the thickness of the support piece 1e3 is thin, making it difficult to show the first insertion hole 1e3a and the second insertion hole 1e3b with dashed lines, so they are shown with solid lines.

[0031] Furthermore, the connecting section 1e includes a pair of left and right reinforcing beams 1e5, 1e5 that are diagonally placed between the connecting member 1e1 and the connecting pipe 1e4. With this configuration, the connecting section 1e becomes a truss structure with the connecting member 1e1, the connecting pipe 1e4 and the reinforcing beams 1e5, 1e5, thereby increasing the strength of the connecting section 1e.

[0032] Next, the joint 4 of this embodiment will be described in detail. As shown in Figure 7, the joint 4 comprises a pair of upper and lower plates 40 and 41 arranged in parallel, and a cylindrical connecting tube portion 42 that connects the upper plate 40 and the lower plate 41. In addition, a U-shaped handle 46 is provided on the outer circumference of the connecting tube portion 42, which functions as a handle when carrying the joint 4.

[0033] In this embodiment, the upper plate 40 and the lower plate 41 are octagonal plates, and eight pin holes 40a, 41a are formed on the same circumference at the points directly opposite the center of each side when viewed from the center of each plate 40, 41. Furthermore, four anti-rotation grooves 40b, 41b are provided on the outer circumference of the upper plate 40 and the lower plate 41 at 90-degree intervals in the circumferential direction, facing each pin hole 40a, 41a in the radial direction of the plates 40, 41 when viewed from the center of each plate 40, 41. Note that the shapes of the upper plate 40 and the lower plate 41 can be any shape, for example, they may be circular or square. Also, the shape of the connecting tube portion 42 is not limited to cylindrical, for example, it may be rectangular.

[0034] Then, as shown in Figure 8, the upper plate 40 is inserted between the upper connecting piece 1e2 and the upper support piece 1e3 at the connection portion 1e of the beam member 1, and the lower plate 41 is inserted between the lower connecting piece 1e2 and the lower support piece 1e3, so that the pin holes 40a and 41a of each plate 40 and 41, the first mounting hole 1e2a of each connecting piece 1e2, the first insertion hole 1e3a of each support piece 1e3 and the inside of the connecting pipe 1e4 are opposed to each other vertically. In this state, by inserting the fixing pin P1 into the first mounting hole 1e2a, the pin holes 40a and 41a, the first insertion hole 1e3a of the support piece 1e3 and the connecting pipe 1e4, the joint 4 is connected to the end of the beam member 1 so that it can rotate horizontally.

[0035] Furthermore, when the beam member 1, which is rotatably connected to the joint 4 by the fixing pin P1, is positioned on the line connecting the pin holes 40a, 41a and the anti-rotation grooves 40b, 41b, the anti-rotation grooves 40b, 41b face the second mounting hole 1e2b of the connecting piece 1e2 and the second insertion hole 1e3b of the support piece 1e3.

[0036] Therefore, when the first mounting hole 1e2a, the pin holes 40a, 41a, and the connecting pipe 1e4 are inserted into the fixing pin P1, and the beam member 1 is positioned on the line connecting the pin holes 40a, 41a and the anti-rotation grooves 40b, 41b, and the anti-rotation pin P2 is inserted into the second mounting hole 1e2b, the anti-rotation pin P2 is also inserted into the anti-rotation grooves 40b, 41b. As a result, the joint 4 is connected to the beam member 1 by two axes, and the joint 4 is fixed to the beam member 1 in a non-rotatable state.

[0037] In this way, the ends of the beam members 1 can be connected to the pin holes 40a and 41a of the joint 4. By connecting the two beam members 1, 1 to the two pin holes 40a and 41a located at 90-degree phase differences, the two adjacent beam members 1, 1 are connected to the joint 4 in a position where they are perpendicular to each other when viewed from above the frame 10, as shown in Figure 2.

[0038] Furthermore, as shown in Figures 7 and 9, a chain fixing hole 43 is provided in the center of the upper plate 40, to which the lower end of the chain 2 can be connected. The chain 2 is formed by connecting multiple annular chain elements 2a in a chain-like fashion. Hereinafter, the side of the chain element 2a facing the hole will be referred to as the front side, the width of the chain element 2a (horizontally oriented chain element 2a) when viewed from the front side will be referred to as the width, and the width of the chain element 2a (vertically oriented chain element 2a) when viewed from the side side will be referred to as the height.

[0039] As shown in Figures 7 and 9, the chain fixing hole 43 has a central hole 43a through which the chain 2 is inserted, four ribbed holes 43b extending radially from the central hole 43a at 90-degree intervals, and notched grooves 43c that cross the extension direction of each ribbed hole 43b. The width of the ribbed holes 43b is wider than the vertical width of the chain element 2a and narrower than the horizontal width of the chain element 2a.

[0040] Then, as shown in Figure 9, with the chain 2 inserted through the central hole 43a, the chain 2 is moved horizontally toward the ribbed hole 43b, and the vertical chain elements 2a of the chain 2 are inserted into the ribbed hole 43b, causing the upper plate 40 to be inserted between the two horizontal chain elements 2a, 2a. Since the width of the ribbed hole 43b is narrower than the width of the horizontal chain elements 2a (the width of the chain elements 2a), the ribbed hole 43b does not allow the horizontal chain elements 2a to pass through. Therefore, when the chain 2 is moved upward relative to the joint 4 with the vertical chain elements 2a inserted into the ribbed hole 43b, the plates 40 and 41 are supported by the horizontal chain elements 2a of the chain 2, so the joint 4 can be lifted by the chain 2.

[0041] Then, with the chain 2 inserted into the rib hole 43b, inserting the fixing plate 44 into the notched groove 43c restricts the horizontal movement of the chain 2, preventing it from coming out of the rib hole 43b. Furthermore, in this embodiment, the fixing plate 44 and the chain 2 are secured by passing the restraining band 45 through the hole 44a provided on the upper end side of the fixing plate 44 and through the chain element 2a of the chain 2, thus preventing the fixing plate 44 from falling off and allowing the joint 4 to be safely lifted by the chain 2.

[0042] In this embodiment, the lower end of the chain 2 is connected to the joint 4 in this manner, but the above-described method of connecting the chain 2 is merely an example, and the method of connecting the chain 2 is not particularly limited as long as it can suspend the frame 10. Furthermore, the lower end of the chain 2 may also be connected to the beam member 1. In addition, the suspension material for suspending the frame 10 is not limited to the chain 2, but may be, for example, a wire.

[0043] Next, the floor structure 3 will be described in detail.Hereinafter, of the four beam members 1 that constitute the frame 10, a pair of beam members 1,1 that face each other in one direction (left-right direction in Figures 2 and 10) will be referred to as one-side beam members 1A,1A, and a pair of beam members 1,1 that face each other in the other direction (up-down direction in Figures 2 and 10), which is perpendicular to the remaining one direction, will be referred to as the other-side beam members 1B,1B.As shown in Figures 2 and 10, the floor structure 3 comprises three first support members 5 that are spanned between the one-side beam members 1A,1A, two second support members 6 that are spanned one by one between the front joints 4,4 in Figure 2 and the rear joints 4,4 in Figure 2, and are positioned parallel to the first support members 5 between the first support members 5 and the other-side beam members 1B, and a floor plate 30 that is supported by the first support members 5 and the second support members 6 and is positioned below the upper end of the upper chord member 1a of the beam member 1. The first support member 5 and the second support member 6 are each U-shaped and project downwards, spanning between the beam members 1,1 and between the joints 4,4. The floorboard 30 is supported by the first support member 5 and the second support member 6. Therefore, in the floor structure 3 of this embodiment, the position of the floorboard 30 can be lowered compared to the conventional method of spanning the floorboard 30 between the beam members 1,1.

[0044] The following describes each part of the floor structure 3 in more detail. As shown in Figure 3, the first support member 5 has a first support portion 50 extending horizontally and first mounting portions 51 extending upward from each end of the first support portion 50, with their upper ends detachably connected to the upper chord member 1a of one side beam member 1A. More specifically, the first support portion 50 is a pipe material with a square cross-section, and has mounting plates 50a that protrude from each side at both ends in the axial direction, and to which the first baseboards 8L and 8R, which will be described later, can be attached. Furthermore, as shown in Figures 3 and 10, a pair of support pieces 50c, 50c are provided at the upper ends of each end of the first support portion 50, which support the first baseboards 8L and 8R, as described later, when viewed from the axial direction of the first support portion 50. In addition, as shown in Figures 2 and 3, the first support portion 50 has mounting plates 50b that protrude from each side in the center in the axial direction, and to which the fixing plates 14, which will be described later, can be attached. Each mounting plate 50a, 50b is provided with a hole and welding nuts 50a1, 50b1 welded to the lower end of the mounting plate 50a, 50b at a position communicating with the hole.

[0045] Furthermore, as shown in Figure 11(A), the first mounting portion 51 has a rectangular tubular upright portion 51a extending upward from the end of the first support portion 50, a flat plate-shaped projection portion 51b connected to the upper end of the upright portion 51a and having its tip projecting toward the opposite side of the first support portion (towards the side of the beam member 1A) along the longitudinal direction of the first support member 5, and a pin 51c projecting from the lower end of the projection portion 51b.

[0046] As shown in Figures 3 and 11(A), the first support member 5 is spanned between the two side beam members 1A by inserting the pins 51c of the first mounting portion 51, which are provided at each end of the first support portion 50, into the holes 1a4 provided in the upper chord member 1a of each side beam member 1A from above. Furthermore, as shown in Figure 3, the upright portion 51a of the first support member 5 is set to a length such that the lower end of the first support portion 50 and the lower end of the lower chord member 1b are aligned horizontally when the first mounting portion 51 is connected to the upper chord member 1a of the side beam member 1A.

[0047] In this embodiment, three first support members 5 are spanned between the two side beam members 1A at predetermined intervals by connecting the ends of the first support members 5 to holes 1a4 provided at three locations: the longitudinal center of the bottom portion 1a2 of the upper chord member 1a of one side beam member 1A, the portion between the center and one end, and the portion between the center and the other end. The number and spacing of the holes 1a4 can be appropriately changed depending on the number of first support members 5 and the spacing at which they are installed. However, the structure of the first mounting portion 51 is not particularly limited as long as it can be detachably connected to the upper chord member 1a of one side beam member 1A. For example, a clamp may be provided at the upper end of the upright portion 51a of the first mounting portion 51, and the upper chord member 1a may be clamped with the clamp so that the first mounting portion 51 can be detachably connected to the upper chord member 1a.

[0048] Furthermore, as shown in Figure 11, each first mounting portion 51 is provided with a locking device 7 at the upper end of the upright portion 51a, which allows the first mounting portion 51 to be fixed in a state where it is connected to the upper chord member 1a of one side beam member 1A. The locking device 7 comprises a locking piece 70 which is arranged parallel to the protrusion 51b and is movable parallel to the protrusion 51b, and which can face the bottom portion 1a2 together with the protrusion 51b, sandwiching the bottom portion 1a2, and a fixing means 71 which can fix the locking piece 70 to the upright portion 51a so that it cannot move.

[0049] More specifically, the locking piece 70 has a pair of L-shaped plates 70a, 70a arranged to sandwich the upright portion 51a, as shown in Figure 11. Each L-shaped plate 70a has a flat, elongated plate 70a1 extending along the left-right direction in Figure 11, and a short plate 70a2 extending vertically along the up-down direction in Figure 11(B) from the base end of the elongated plate 70a1 (right end in Figure 11(B)). The elongated plate 70a1 also has an elongated hole 70a3 that is long in the left-right direction.

[0050] The fixing means 71 includes a bolt 71a that penetrates the upright portion 51a in the vertical direction in Figure 11(B), and a nut 71b that is screwed onto the threaded portion of the bolt 71a. As shown in Figure 11(B), the upright portion 51a is sandwiched between the long plates 70a1, 70a1 of each L-shaped plate 70a in the vertical direction in Figure 11(B), and the ends of the short plates 70a2 of each L-shaped plate 70a are brought into contact with the opposite side of the upright portion 51a (right side in Figure 11(B)). When the L-shaped plates 70a, 70a are tightened with the bolt 71a inserted into the elongated hole 70a3 and the nut 71b screwed onto the bolt 71a, they are fixed to the upright portion 51a. Furthermore, the locking piece 70 is fixed in a position parallel to the protruding portion 51b, as rotation around the bolt 71a is prevented by the short plate 70a2 contacting the upright portion 51a. In addition, a stopper portion 71d is provided at the opposite end of the bolt 71a to prevent the nut 71b from falling off.

[0051] The length of the elongated hole 70a3 is set to a length that allows the locking piece 70 to move within a range from a position where the tip of the L-shaped plate 70a faces the lower surface of the bottom 1a2, which is at least a part of the upper chord member 1a of one side beam member 1A, in the vertical direction, to a position where it does not face the lower surface of the bottom 1a2 of the upper chord member 1a in the vertical direction.

[0052] When the locking piece 70 is fixed in the locked position, where it is sandwiched together with the protrusion 51b, the pin 51c cannot be pulled out of the hole 1a4, preventing the first support member 5 from falling off the one-sided beam member 1A. Thus, the first mounting portion 51 can be fixed in a connected state to the upper chord member 1a. Furthermore, when the locking piece 70 is moved to the locked position, if the short plate 70a2 of the L-shaped plate 70a is brought into contact with the surface of the upright portion 51a opposite the pin, the short plate 70a2 will come into contact with the upright portion 51a, restricting the rotation of the locking piece 70 around the bolt 71a as an axis. Thus, the nut 71b can be tightened while the locking piece 70 is maintained in a position parallel to the protrusion 51b. Thus, the locking piece 70 can be easily fixed in the locked position.

[0053] Conversely, when the locking piece 70 is moved to an unlocked position where the L-shaped plate 70a does not face the lower surface of the bottom 1a2 of the upper chord member 1a of one side beam member 1A in the vertical direction, the insertion and removal of the pin 51c into the hole 1a4 is not obstructed by the locking piece 70, so the first support member 5 can be freely attached to and detached from the one side beam member 1A.

[0054] As described above, in the locking device 7 of this embodiment, the locking piece 70 is fixed to the upright portion 51a in the locked position, which prevents the first support member 5 from falling off the one side beam member 1A. When the locking piece 70 is moved to the unlocked position, the first support member 5 can be freely attached to and detached from the one side beam member 1A.

[0055] The configuration of the locking device 7 described above is merely an example, and the configuration of the locking device 7 is not particularly limited as long as the first mounting portion 51 can be fixed in a connected state to the upper chord member 1a. However, in this embodiment, the locking device 7 consists only of a locking piece 70 and a fixing means 71, thus reducing the number of parts. Furthermore, in the locking device 7 of this embodiment, the first support member 5 can be carried with the locking piece 70 and fixing means 71 still attached to the first mounting portion 51, so there is no need to attach the locking device 7 to the first support member 5 when connecting the first support member 5 to one side beam member 1A.

[0056] Furthermore, in the locking device 7 of this embodiment, the fixing means 71 is composed of a bolt 71a and a nut 71b, but the fixing means 71 is not particularly limited as long as it can fix the locking piece 70 immovably to the upright portion 51a at least in the locked position. For example, the fixing means may be a pin, and instead of the elongated hole 70a3, a hole may be provided in the locking piece 70 at a position opposite to the through hole formed in the upright portion 51a when the locking piece 70 on the L-shaped plate 70a is in the locked position, and the pin as the fixing means may be inserted into the through hole in the upright portion 51a and the hole in the L-shaped plate 70a to fix the locking piece 70 immovably to the upright portion 51a in the locked position. However, the locking device 7 may be omitted.

[0057] Next, the second support member 6, which is positioned parallel to the first support member 5 between the first support member 5 and the other side beam member 1B, will be described in detail. As shown in Figures 2, 10, 12, and 15, the second support member 6 has a second support portion 60 extending parallel to the first support portion 50, and second mounting portions 61 provided at each end of the second support portion 60 and detachably connected to each joint 4 facing each other in one direction. More specifically, the second support portion 60 is a pipe material with a square cross-section, and has mounting plates 60a protruding from each side at both ends in the axial direction. Furthermore, the second support portion 60 has a mounting plate 60b that protrudes from the side on the first support member 5 side in the axial center, and to which a fixing plate 14, which will be described later, can be attached. Each mounting plate 60a, 60b is provided with a hole and welding nuts 60a1, 60b1 welded at a position communicating with the hole at the lower end of the mounting plates 60a, 60b.

[0058] Furthermore, as shown in Figures 10 and 13, the second mounting portion 61 has a rectangular tubular upright portion 61a extending upward from the end of the second support portion 60, a flat plate-shaped first projection 61b projecting from the upper end of the upright portion 61a toward the opposite side of the first support member, and a second projection 61c projecting from the lower end of the upright portion 61a toward the opposite side of the first support member and facing the first projection 61b in the vertical direction. The first projection 61b and the second projection 61c each have opposing holes 61b1 and 61c1 facing each other. In the figures, the first projection 61b is formed in the shape of a rectangular plate, but the shape of the first projection 61b is not particularly limited.

[0059] In this embodiment, the second projection 61c is constructed with an L-shaped piece having an L-shaped cross-section, consisting of a flat vertical piece 61c2 arranged along the outer circumference of the upright portion 61a and welded to the lower end of the upright portion 61a, and a flat horizontal piece 61c3 extending horizontally from the lower end of the vertical piece 61c2 and having an opposing hole 61c1 at its tip, and a pair of reinforcing pieces 61c4, 61c4, consisting of a reinforcing piece 61c4 connected to the left end of the vertical piece 61c2 and the left end of the horizontal piece 61c3, and a reinforcing piece 61c4 connected to the right end of the vertical piece 61c2 and the right end of the horizontal piece 61c3. The second projection 61c is joined to the upright portion 61a by welding the periphery of the vertical piece 61c2, which is arranged along the outer circumference of the upright portion 61a, to the upright portion 61a. Therefore, since the second projection 61c is formed in a box shape and the periphery of the vertical piece 61c2 is welded to the upright portion 61a, it can be welded more firmly to the upright portion 61a compared to the case where the second projection 61c is a flat plate. However, the shape of the second projection 61c is not particularly limited as long as the support strength against the load is sufficient. In addition, the upright portion 61a of each second mounting portion 61 is provided with a positioning pin 61d that protrudes laterally from above the axial center toward the auxiliary mounting portion 62.

[0060] Furthermore, the second support member 6 has a rectangular tubular cross-section and an upright portion 62a that extends upward and is connected at its lower end to the side of the second support portion 60 on the other beam member 1B side at the axial center; a flat plate-shaped projection 62b connected to the upper end of the upright portion 62a and having its tip projecting toward the other beam member 1B side; and a pin 62c projecting from the lower end of the projection 62b, and is equipped with an auxiliary mounting portion 62 that is detachably connected to the upper chord member 1a of the other beam member 1B. In addition, the upright portion 62a of the auxiliary mounting portion 62 is provided with a through hole (not shown) that penetrates the side surface of the upright portion 62a along the axial direction of the second support portion 60, at the same height as the positioning pin 61d of the second mounting portion 61.

[0061] Then, as shown in Figures 10 and 13, with the first protrusions 61b and 2 protrusions 61c of the second mounting portions 61 provided at each end of the second support portion 60 superimposed on the upper plate 40 and lower plate 41 of the joints 4 facing each other in one direction of the frame 10, the connecting pins P3 are inserted from above into the opposing holes 61b1 and 61c1 of the protrusions 61b and 61c and the pin holes 40a and 41a of the plates 40 and 41 (pin holes 40a and 41a located between the pin holes 40a and 41a into which the fixing pins P1 connecting the ends of one side beam member 1A are inserted and the pin holes 40a and 41a into which the fixing pins P1 connecting the ends of the other side beam member 1B are inserted), thereby connecting the second support member 6 so as to span across the joints 4, 4 facing each other in one direction of the frame 10, and is positioned parallel to the first support member 5 between the first support member 5 and the other side beam member 1B.

[0062] Furthermore, by inserting the pin 62c of the auxiliary mounting portion 62 into the hole 1a4 provided in the longitudinal center of the bottom portion 1a2 of the upper chord member 1a of the other beam member 1B from above, the vicinity of the axial center of the second support member 6 is connected to the vicinity of the longitudinal center of the other beam member 1B, as shown in Figure 10. In this way, since the second support member 6 is supported not only by the joints 4,4 but also by the other beam member 1B, the load-bearing strength of the second support member 6 can be increased compared to the case where each end of the second support member 6 is connected only to the opposing joints 4,4 in one direction.

[0063] Thus, in this embodiment, even if a hole 1a4 is not provided near the end of the upper chord 1a of one side beam member 1A, the second support member 6 can be installed close to the other side beam member 1B inside the frame 10 by utilizing the pin holes 40a and 41a of the joint 4 facing each other in one direction. However, a hole 1a4 may also be provided near the end of the upper chord 1a of one side beam member 1A, and the first support member 5 may be placed between the ends of the one side beam members 1A, 1A instead of the second support member 6.

[0064] Furthermore, the lengths of the upright portion 61a of the second mounting portion 61 and the upright portion 62a of the auxiliary mounting portion 62 in the second support member 6 are set such that, with the second mounting portion 61 connected to the joint 4 and the auxiliary mounting portion 62 connected to the other side beam member 1B, the lower end of the second support portion 60 aligns horizontally with the lower end of the first support portion 50 of the first support member 5.

[0065] The structure of the second mounting portion 61 and the auxiliary mounting portion 62 is not particularly limited, as long as they can be detachably connected to the joint 4 and the upper chord member 1a of the other beam member 1B, respectively. For example, clamps may be provided at the upper ends of the upright portions 61a and 62a, respectively, and the upper plate 40 of the joint 4 and the upper chord member 1a may be clamped with these clamps, thereby enabling the second mounting portion 61 and the auxiliary mounting portion 62 to be detachably connected to the joint 4 and the upper chord member 1a of the other beam member 1B, respectively. The auxiliary mounting portion 62 may be omitted if the strength of the second support member 6 against load is sufficient.

[0066] As shown in Figure 2, the floorboard 30 is composed of two plates 30a installed on each of the first support parts 50 and each of the second support parts 60. Furthermore, as shown in Figure 2, the two plates 30a are pressed down by each of the support members 5 and 6 by a fixing plate 14 installed from above between the two plates 30a, so that the plates 30a are fixed to the first support parts 50 and the second support parts 60, and the floorboard 30 is prevented from being lifted up by wind or other forces through the gap between the plates 30a, 30a. Although not shown in detail, the fixing plate 14 consists of multiple metal plates arranged along the other direction (up and down direction in Figure 2) of the frame 10, and fixing holes are provided in the fixing plate 14 at positions opposite to the holes in the mounting plate 50b provided in the axial center of the first support part 50 and the holes in the mounting plate 60b provided in the axial center of the second support part 60. Then, as shown in Figures 3 and 15, bolts 17 are inserted into the fixing holes of the fixing plate 14 and the holes of each mounting plate 50b, 60b, and screwed into the weld nuts 50b1, 60b1 provided at the lower end of each mounting plate 50b, 60b, thereby fastening the fixing plate 14 to each mounting plate 50b, 60b with screws.

[0067] The number of boards 30a that make up the floorboard 30 is not particularly limited and may be one or three or more. If the floorboard 30 is made up of one board 30a, there will be no gaps in the floorboard 30, so it will not be necessary to install a fixing plate 14 to prevent the floorboard 30 from lifting up from the center.

[0068] Furthermore, in this embodiment, the floorboard 30 is supported by three first support members 5 and two second support members 6, but the number of each support member 5, 6 is not particularly limited as long as sufficient strength against the load of the floorboard 30 is ensured.

[0069] Furthermore, the first support section 50 and the second support section 60 are positioned horizontally opposite to the lower chord members 1b of each beam member 1 in the frame 10. Therefore, the upper surfaces of the first support section 50 and the second support section 60 that the floor plate 30 contacts are located below the upper end of the upper chord member 1a of the beam member 1 in the frame 10. Consequently, when the floor plate 30 is installed on the first support section 50 and the second support section 60, the floor plate 30 is located at least below the upper end of the upper chord member 1a of each beam member 1, so the position of the floor plate 30 is lower compared to the conventional case where the floor plate is stretched between the upper chord members 1a, 1a of opposing beam members 1, 1. Thus, as shown in Figure 1, sufficient working space can be secured between the lower surface of the main girder 11a of the bridge 11 as a structure and the floor plate 30.

[0070] Furthermore, as mentioned above, since the lower ends of the first support portion 50 and the second support portion 60 in the floor structure 3 and the lower ends of the lower chord members 1b of each beam member 1 in the frame 10 are aligned horizontally, the lower end of the floor structure 3 does not extend beyond the lower end of the frame 10.

[0071] Therefore, in the suspended scaffolding F of this embodiment, the position of the floor plate 30 can be lowered by a height close to the height of the beam member 1, without lowering the position of the lower end of the suspended scaffolding F. As a result, even if the position of the floor plate 30 is lowered compared to the conventional position to secure a large working space between the underside of the bridge 11 and the floor plate 30, the lower end of the floor structure 3 does not protrude from the lower end of the frame 10. Therefore, without lowering the height from the lower end of the suspended scaffolding F to the road or the water surface of a river or the sea below the bridge 11, it is possible to lower the floor plate 30 and work can be performed even in places where there is a main girder 11a, thus ensuring sufficient height at the lower end of the suspended scaffolding F. As a result, the suspended scaffolding F does not obstruct the passage of ships, etc., so there is no need to raise the suspended scaffolding F every time a large vehicle or ship passes underneath it.

[0072] Furthermore, if the floorboard 30 is positioned below the upper end of the upper chord member 1a, and the lower ends of the first support part 50 and the second support part 60, which form the lower end of the floor structure 3, are positioned at a height equal to or greater than the lower end of the lower chord member 1b of each beam member 1 that constitutes the frame 10, then the lower ends of the first support part 50 and the second support part 60 do not need to be horizontally aligned with the lower end of the lower chord member 1b. Even in that case, the floorboard 30 is positioned at least below the upper end of the upper chord member 1a of each beam member 1, so the position of the floorboard 30 can be lowered compared to the conventional case where the floorboard is stretched between the upper chord members 1a, 1a of opposing beam members 1, 1. However, if the lower ends of the first support part 50 and the second support part 60 are horizontally aligned with the lower end of the lower chord member 1b, the position of the floorboard 30 can be lowered to the maximum extent possible without changing the height from the lower end of the suspended scaffolding F to the road or the water surface of a river or sea below the bridge 11. Therefore, within the range where the height of the lower end of the suspended scaffolding F does not change, the working space between the underside of the main girder 11a of the bridge 11 and the floor plate 30 can be made as wide as possible.

[0073] Furthermore, as shown in Figure 2, the floor structure 3 includes a plurality of baseboards, namely first baseboards 8L, 8R and second baseboards 9L, 9R, which are arranged in a row along the outer edge of the floorboard 30. Two first baseboards 8L, 8R are arranged side by side on the inside of each side beam member 1A in Figure 14. Two second baseboards 9L, 9R are arranged side by side on the inside of each other side beam member 1B in Figure 15. Note that in Figure 14, the illustration of the second baseboards 9L, 9R is omitted in order to clearly explain the first baseboards 8L, 8R.

[0074] As shown in Figures 11(A) and 14, the first baseboards 8L and 8R comprise a lower plate body 80 with an L-shaped cross-section extending along the longitudinal direction of one side beam member 1A, and two upper plate bodies 81, 81 connected to the lower plate body 80 near the upper end, with a predetermined interval between them in Figure 14. The upper plate bodies 81 have an L-shaped cross-section with a width shorter in the left and right directions than the lower plate body 80 in Figure 14. Their base end is connected to the upper end of the outer surface of the lower plate body 80 facing the one side beam member 1A, and their tip end extends toward the one side beam member 1A. In this embodiment, the widths of the two upper plate bodies 81 in each of the first baseboards 8L and 8R are different in the left-right direction in Figure 14, but the other components are the same and are therefore described using the same reference numerals.

[0075] More specifically, as shown in Figures 11(A) and 14, the lower plate body 80 is formed in an L-shape in cross-section, having a rectangular plate-like connecting piece 80a whose lower surface is supported by the support pieces 50c of each first support part 50, and a vertical piece 80b that rises vertically from one side beam member 1A end of the connecting piece 80a (left end in Figure 11(A)). Furthermore, the connecting piece 80a is provided with a plurality of openings 80c that face the holes in each mounting plate 50a of the first support part 50 and the holes in each mounting plate 60a of the second support part 60, respectively, when the connecting piece 80a is supported by the support pieces 50c of the first support part 50. As shown in Figure 11(A), the openings 80c are formed in a roughly frustoconical shape that tapers downwards by making holes in the connecting piece 80a and processing the edges of the holes so that they are bent downwards. Here, the upper end of the support piece 50c is set to a height that is aligned with the upper end of the floor plate 30, as shown in Figure 11(A). Therefore, the connecting piece 80a supported by the support piece 50c abuts against the upper surface of the floor plate 30 and does not interfere with the side edge of the floor plate 30.

[0076] Then, with the connecting piece 80a supported by the support piece 50c of the first support part 50, bolts 12 are inserted into the openings 80c of the opposing connecting pieces 80a and the holes in the mounting plates 50a and 60a, respectively. When these bolts 12 are screwed into the weld nuts 50a1 and 60a1 provided at the lower ends of the mounting plates 50a and 60a, the connecting piece 80a is clamped between the heads of the bolts 12 and the support piece 50c of the first support part 50, thereby connecting the first baseboards 8L and 8R to the first support part 50 and the second support part 60.

[0077] Here, the diameter of the lower end of the opening 80c is larger than the shaft of the bolt 12 but smaller than the head. Therefore, the head of the bolt 12 is housed within the opening 80c and abuts against the inner circumference of the lower end of the opening 80c. Consequently, the head of the bolt 12 is housed within the opening 80c and does not protrude above the floorboard 30. Thus, it is possible to prevent workers from tripping over the head of the bolt 12, or for a sheet to get caught on the head of the bolt 12 and be damaged when covering the floorboard 30 with a sheet. However, the opening 80c may also be a simple hole with a diameter larger than the shaft of the bolt 12 and smaller than the head of the bolt 12. In addition, in this embodiment, as shown in Figure 11(A), the right end of the connecting piece 80a of the first baseboards 8L and 8R is positioned on the floorboard 30, so the connecting piece 80a of the first baseboards 8L and 8R prevents the floorboard 30 from lifting up.

[0078] The method of connecting the first baseboards 8L and 8R to the first support member 5 and the second support member 6 described above is merely an example and is not particularly limited. Furthermore, the first baseboards 8L and 8R may be detachably connected to a configuration other than the first support member 5 and the second support member 6, for example, to one side beam member 1A.

[0079] Furthermore, the lower plate body 80 in this embodiment has a downward L-shaped reinforcing portion 80d that protrudes from the upper end of the vertical piece 80b toward the opposite beam member side (right side in Figure 11(A)). By having such a reinforcing portion 80d, the strength of the lower plate body 80 can be ensured even if the thickness of the lower plate body 80 is reduced. However, if the strength of the lower plate body 80 is not insufficient, the reinforcing portion 80d may be omitted.

[0080] Furthermore, elliptical positioning holes 80e are provided above the left end of the vertical piece 80b of the first baseboard 8L on the left side of Figure 14, and above the right end of the vertical piece 80b of the first baseboard 8R on the right side of Figure 14. These positioning holes 80e are positioned at the same height as the positioning pins 61d that protrude laterally from the upright portion 61a of each second mounting portion 61 in the second support member 6, when the connecting piece 80a of the first baseboards 8L and 8R is supported by the support piece 50c of the first support portion 50. Therefore, as shown in Figures 15 and 16, when the positioning pins 61d of each second mounting portion 61 are inserted into the positioning holes 80e of the vertical piece 80b of each first baseboard 8L and 8R, the first baseboards 8L and 8R can be positioned so that the mounting holes of the connecting piece 80a face the holes of each mounting plate 50a and 60a, thus facilitating the installation of the first baseboards 8L and 8R.

[0081] As shown in Figure 11(A), each upper plate body 81 has a rectangular plate-shaped connecting plate portion 81a that extends upward and is connected to the outer surface (left side in Figure 11(A)) facing the one-sided beam member 1A side near the upper end of the vertical piece 80b, and an upper closing plate portion 81b that extends horizontally from the upper end of the connecting plate portion 81a toward the one-sided beam member 1A side (left side in Figure 11(A)), and is formed in an L-shape in cross-section.

[0082] In this embodiment, the connecting plate portion 81a of the upper plate body 81 is connected to the vertical piece 80b of the lower plate body 80 by a plurality of rivets 82. However, the method of connecting the upper plate body 81 to the lower plate body 80 is not particularly limited, and they may be connected, for example, by screw fastening with bolts and nuts or by welding. Also, in this embodiment, in order to facilitate manufacturing, the first baseboards 8L and 8R are formed by connecting the lower plate body 80 and the upper plate body 81 which are manufactured separately. However, the first baseboards 8L and 8R may also be formed by integrating the lower plate body 80 and the upper plate body 81.

[0083] The upper end of the connecting plate portion 81a is located at the same height horizontally as the bottom 1a2 of the upper chord member 1a of one side beam member 1A, and together with the vertical piece 80b of the lower plate body 80, the connecting plate portion 81a constitutes a lateral closing plate portion that closes the gap between the upper chord member 1a and the lower chord member 1b of one side beam member 1A.

[0084] Furthermore, as shown in Figure 11(A), the upper closing plate portion 81b extends horizontally from the upper end of the connecting plate portion 81a toward the one-sided beam member 1A, and the lower surface of the tip end abuts against the upper end of the bottom 1a2 of the upper support piece 1a1 on the right side in the figure of the upper chord member 1a of the one-sided beam member 1A. As a result, the upper closing plate portion 81b closes the gap between the one-sided beam member 1A in the frame 10 and the floor plate 30 of the floor structure 3.

[0085] Furthermore, as shown in Figure 14, two upper plate bodies 81 are arranged side by side with a gap between them at the upper end of the lower plate body 80, so there is a gap between the two upper plate bodies 81, 81. In addition, the right end of the right upper plate body 81 in the first baseboard 8L on the left side of Figure 14 is located slightly to the left of the right end of the lower plate body 80. Also, the left end of the left upper plate body 81 in the first baseboard 8R on the right side of Figure 14 is located slightly to the right of the left end of the lower plate body 80. Therefore, there is also a gap between the right upper plate body 81 in the first baseboard 8L on the left side of Figure 14 and the left upper plate body 81 in the first baseboard 8R on the right side of Figure 14. These gaps are located at positions corresponding to the portions where the holes 1a4 are provided in the upper chord member 1a of one side beam member 1A. In this context, the corresponding position means that, when viewing the first baseboards 8L and 8R from the front, the gap between the upper plate bodies 81 and 81 is located opposite the portion of the bottom 1a2 of the upper chord member 1a of one side beam member 1A where the hole 1a4 is provided. Therefore, even if the first baseboards 8L and 8R, each having an upper closing plate portion 81b that abuts against the bottom portion 1a2 of the upper chord member 1a, are installed along the longitudinal direction of one side beam member 1A, the first mounting portion 51 of the first support member 5 can be connected to the upper chord member 1a of the first support member 5 by passing the protruding portion 51b of the first mounting portion 51 of the first support member 5 through the gaps between the upper plate bodies 81, 81 of the first baseboards 8L and 8R and the gap between the upper plate body 81 of the first baseboard 8L and the upper plate body 81 of the first baseboard 8R, respectively, and inserting the pin 51c provided at the tip of the protruding portion 51b into the hole 1a4 provided in the upper chord member 1a. As shown in Figure 14, the vertical piece 80b of the first baseboard 8L on the left side of the figure and the vertical piece 80b of the first baseboard 8R on the right side of the figure overlap front to back, so that there is no gap between the vertical pieces 80b of the first baseboards 8L and 8R.

[0086] Thus, the first baseboards 8L and 8R close the gap between the upper chord 1a and lower chord 1b of one side beam member 1A with a lateral closing plate portion composed of the vertical piece 80b of the lower plate body 80 and the connecting plate portion 81a of the upper plate body 81, and close the gap between one side beam member 1A and floorboard 30 with the upper closing plate portion 81b of the upper plate body 81. Therefore, it is possible to prevent tools and the like from falling through the gap between the upper chord 1a and lower chord 1b of one side beam member 1A and the gap between one side beam member 1A and floorboard 30.

[0087] Next, the second baseboards 9L and 9R will be described in detail. As shown in Figure 15, the second baseboard 9L on the left side of the figure is positioned between the upright portion 61a of the second mounting portion 61 on the left side of the second support member 6 and the upright portion 62a of the auxiliary mounting portion 62, and the second baseboard 9R on the right side of the figure is positioned between the upright portion 61a of the second mounting portion 61 on the right side of the figure and the upright portion 62a of the auxiliary mounting portion 62.

[0088] As shown in Figures 15, 16, and 17, the second baseboards 9L and 9R have a rectangular plate-shaped bottom plate portion 90 that is placed on the floorboard 30 and extends along the longitudinal direction of the other side beam member 1B, a rectangular plate-shaped closing plate portion 91 that rises upward from the other side beam member 1B end of the bottom plate portion 90 and closes the gap between the upper chord member 1a and the lower chord member 1b of the other side beam member 1B, and a pair of side plate portions 92, 92 that rise from the left and right ends of the closing plate portion 91 in Figure 17 toward the opposite side beam member and are longer than the bottom plate portion 90. In addition, the left and right ends of the bottom plate portion 90 in Figure 17 are connected to the lower ends of the side plate portions 92, 92, respectively.

[0089] Furthermore, near the left end of the bottom plate portion 90 of the second baseboard 9L on the left side of Figure 15, and near the right end of the bottom plate portion 90 of the second baseboard 9R on the right side of Figure 15, openings 90a are provided that face the holes in the mounting plates 60a provided at each axial end of the second support portion 60. As shown in Figure 16, the openings 90a are formed in a roughly frustoconical shape that tapers downwards by drilling holes in the bottom plate portion 90 and processing the edges of the holes so that they are bent downwards. Then, bolts 93 are inserted into the openings 90a of the opposite bottom plate portions 90 and the holes in each mounting plate 60a, respectively, and the bolts 93 are screwed into the weld nuts 60a1 provided at the lower end of each mounting plate 60a, so that the bottom plate portion 90 is pressed against the mounting plate 60a by the heads of the bolts 93 and fixed in place.

[0090] Here, the diameter of the lower end of the opening 90a is larger than the shaft of the bolt 93 but smaller than the head. Therefore, the head of the bolt 93 is housed within the opening 90a and abuts against the inner circumference of the lower end of the opening 90a. Consequently, the head of the bolt 93 is housed within the opening 90a and does not protrude above the floorboard 30. Thus, it is possible to prevent workers from tripping over the head of the bolt 93, or for the sheet to get caught on the head of the bolt 93 and be damaged when the floorboard 30 is covered with a sheet. However, even if the opening 90a is simply a hole with a diameter larger than the shaft of the bolt 93 but smaller than the head of the bolt 93, the bottom plate portion 90 can still be pressed and fixed to the mounting plate 60a by the head of the bolt 93. Also, although not shown in the figures, the tip portions of the bottom plate portions 90 of the second baseboards 9L and 9R are positioned on top of the floorboard 30, thus preventing the floorboard 30 from lifting up.

[0091] Furthermore, as shown in Figure 17, each side plate portion 92 is provided with an elliptical elongated hole 92a. These elongated holes 92a are positioned to correspond to the positioning pin 61d provided on the second mounting portion 61 of the second support member 6 and to an out-of-figure through hole provided on the upright portion 62a of the auxiliary mounting portion 62. Therefore, as shown in Figure 15, by inserting the positioning pin 61d provided on the second mounting portion 61 into the elongated hole 92a of one side plate portion 92, the second baseboards 9L, 9R can be positioned so that the opening 90a of the bottom plate portion 90 faces the hole in the mounting plate 60a. At this time, as shown in Figure 16, one side plate portion 92 of the second baseboards 9L, 9R overlaps with the lower plate body 80 of the first baseboards 8L, 8R, so that there is no gap between the first baseboards 8L, 8R and the second baseboards 9L, 9R. Furthermore, as shown in Figure 15, with the other side plate portion 92 of each second baseboard 9L, 9R sandwiching the upright portion 62a of the auxiliary mounting portion 62 from both the left and right sides in Figure 15, bolts 94 are inserted into the elongated holes 92a of the opposing side plate portions 92 and the through holes of the auxiliary mounting portion 62, and nuts 95 are screwed onto the threaded portion of the bolts 94, thereby connecting the other side plate portion 92 of the second baseboard 9L, 9R to the auxiliary mounting portion 62.

[0092] The method of connecting the second baseboards 9L and 9R to the second support member 6 described above is merely an example and is not particularly limited. Furthermore, the second baseboards 9L and 9R may be detachably connected to a configuration other than the second support member 6, for example, to the other side beam member 1B.

[0093] Furthermore, the second baseboards 9L and 9R close the gap between the upper chord 1a and lower chord 1b of the other side beam member 1B with the closing plate portion 91, thereby preventing tools and other objects from falling through the gap between the upper chord 1a and lower chord 1b of the other side beam member 1B.

[0094] Furthermore, as shown in Figures 15, 16, and 17, the upper end of the closing plate portion 91 is provided with a downward-facing L-shaped first reinforcing portion 91a that protrudes inward from the upper end of the closing plate portion 91 toward the inside of the frame 10. Similarly, the upper end of the side plate portion 92 is provided with a downward-facing L-shaped second reinforcing portion 92b that protrudes inward from a part of the upper end of the side plate portion 92 toward the inside of the frame 10 without interfering with the first reinforcing portion 91a. In this way, the second baseboards 9L and 9R are equipped with the first reinforcing portion 91a and the second reinforcing portion 92b, ensuring strength even with a thin plate thickness. Note that in Figure 17, there is no gap between the first reinforcing portion 91a and the second reinforcing portion 92b, but a gap may exist between them. However, if the strength of the second baseboards 9L and 9R is sufficient, the reinforcing portions 91a and 92b may be omitted.

[0095] Furthermore, each closing plate portion 91 of the second baseboards 9L and 9R is provided with a recess 91b formed by cutting out the upper end of a portion of the upper chord member 1a of the other side beam member 1B at a position corresponding to the portion where a hole 1a4 is provided, located between the longitudinal center and one end and between the longitudinal center and the other end of the bottom portion 1a2 of the upper chord member 1a of the other side beam member 1B. The corresponding position here refers to the position where, when viewing the second baseboards 9L and 9R from the front, the portion of the upper chord member 1a of the other side beam member 1B at the bottom portion 1a2 where the hole 1a4 is provided fits within the recess 91b of the closing plate portion 91.

[0096] Furthermore, as mentioned above, in the suspended scaffolding F of this embodiment, the first support portion 50 of the first support member 5 and the second support portion 60 of the second support member 6 that support the floor plate 30 are positioned at the same height as the lower chord members 1b of each beam member 1 in the frame 10. Therefore, compared to the conventional method of placing the floor plate between the upper chord members 1a, 1a of opposing beam members 1, 1, the position of the floor plate 30 is lower, and sufficient working space can be secured between the underside of the main girder 11a of the bridge 11 and the floor plate 30. However, when the position of the floor plate 30 is lowered in this way, maintenance work on areas higher than the lower end of the main girder 11a of the bridge 11, for example, on the side of the main girder 11a, becomes more difficult by the amount the floor plate 30 is lowered. In such cases, the suspended scaffolding F of this embodiment can be provided with a support beam 15 spanning between the upper chord members 1a, 1a of opposing other side beam members 1B, 1B, and a raised floor 16 supported by the support beam 15, as shown in Figures 18 and 19. In this way, workers can easily perform maintenance work on high positions such as the sides of the main girders 11a of the bridge 11 by using the raised floor 16, which is higher than the lowered floorboards 30, as scaffolding.

[0097] To explain in detail, in this embodiment, as shown in Figure 18, two support beams 15 are spanned between the other side beam members 1B, 1B in the frame 10 at a predetermined distance apart in one direction (left-right direction in the figure). As shown in Figures 18 and 19, the support beam 15 comprises a rectangular tubular support beam body 15a that extends horizontally along the other direction (up-down direction in Figure 18) of the frame 10, and attachment parts 15b provided at each end of the support beam body 15a that can be connected to the upper chord member 1a of the beam member 1.

[0098] As shown in Figure 19, the mounting portion 15b has a flat plate body 15b1 that protrudes axially from the upper end of the end of the support beam body 15a, and a pin 15b2 that protrudes downward from the lower end of the plate body 15b1.

[0099] Then, by inserting the pins 15b2 of the mounting portion 15b of each support beam 15 into the holes 1a4 on the left and right sides in Figure 18, which are provided between the longitudinal center and one end and between the longitudinal center and the other end of the bottom portion 1a2 of the upper chord member 1a of the other side beam member 1B, the ends of the support beams 15 can be detachably connected to the upper chord member 1a of the other side beam member 1B.

[0100] As mentioned above, the second baseboards 9L and 9R, which are positioned inside the other beam member 1B in the frame 10, have recesses 91b at their upper ends corresponding to the portions of the upper chord member 1a of the other beam member 1B where the left and right holes 1a4 in Figure 18 are provided. Therefore, even if the second baseboards 9L and 9R are installed inside the other beam member 1B in the frame 10, the support beam body 15a can be inserted into the holes 1a4 by inserting the pins 15b2 of the mounting portion 15b into the holes 1a4, thereby bridging the support beam 15 between the upper chord members 1a, 1a of the other beam members 1B, 1B that are facing each other, without interfering with the second baseboards 9L and 9R.

[0101] As described above, in this embodiment, the support beam 15 is stretched between the upper chord members 1a, 1a of the other side beam members 1B, 1B, which are separate from the one side beam member 1A to which the first mounting portion 51 of the first support member 5 is connected. In this case, even if the first mounting portion 51 of the first support member 5 is connected to the upper chord member 1a of the one side beam member 1A using a hole 1a4 provided in the upper chord member 1a of the one side beam member 1A, the hole 1a4 provided in the upper chord member 1a of the other side beam member 1B can be used when connecting the end of the support beam 15 to the upper chord member 1a of the other side beam member 1B.Therefore, it is not necessary to provide a hole for connecting the end of the support beam 15 in addition to the hole 1a4 for connecting the first mounting portion 51 of the first support member 5 in the upper chord member 1a of the beam member 1. However, the support beam 15 may be spanned between the two side beam members 1A by providing an additional hole in the upper chord member 1a of one side beam member 1A and connecting the mounting portion 15b of the support beam 15 to the hole.

[0102] Furthermore, as shown in Figure 18, the raised floor 16 is composed of a central plate 16a that spans between the upper chord members 1a, 1a of one side beam members 1A, 1A and is supported by the left and right support beams 15, 15 in the figure, a left side plate 16b that spans between the upper chord members 1a, 1a of one side beam members 1A, 1A and is supported by the upper chord member 1a of the left side beam member 1A in the figure and the left support beam 15 in the figure, and a right side plate 16c that spans between the upper chord members 1a, 1a of one side beam members 1A, 1A and is supported by the upper chord member 1a of the right side beam member 1A in the figure and the right support beam 15 in the figure. Here, the upper end of the support beam body 15a of the support beam 15 is provided with a restricting portion 15c that rises from the center in the width direction and extends along the axial direction. Therefore, the horizontal movement of each plate 16a, 16b, and 16c constituting the raised floor 16 is restricted by the restricting portion 15c of the support beam 15 and the vertical portion 1a3 of the upper chord member 1a of each beam member 1.

[0103] The number of support beams 15 is not particularly limited. Furthermore, the number of boards constituting the raised floor 16 is also not particularly limited; for example, the restricting portion 15c of the support beams 15 may be omitted, and the raised floor 16 may be constructed using a single board.

[0104] Thus, in the suspended scaffolding F of this embodiment, the raised floor 16 can be installed above the floor 30, which is located below the upper chord of the beam member 1 in the frame 10, while the floor 30 remains in place. Therefore, the height of the work scaffolding can be adjusted by attaching and detaching the support beam 15 and the raised floor 16.

[0105] Next, the assembly method of the suspended scaffolding F of this embodiment will be described in detail. First, other suspended scaffolding F1 assembled on the ground or on the deck slab 11b of the bridge 11 is suspended from the left and right sides of the main girder 11a of the bridge 11 in Figure 1, respectively, using heavy machinery such as a crane. Here, although not shown, the other suspended scaffolding F1 is constructed by stretching a floor plate between the upper chord members 1a, 1a of the opposing beam members 1, 1 in the frame 10 of the suspended scaffolding F of this embodiment. Therefore, the floor plate of the suspended scaffolding F1 is positioned at approximately the same height as the upper end of the upper chord member 1a. However, the other suspended scaffolding F1 may have the same configuration as the suspended scaffolding F of this embodiment, but with support beams 15 and raised floor 16 installed.

[0106] Next, two workers, from the floorboards of the other suspended scaffolding F1, F1, each hold the ends of the other-side beam members 1B and connect the ends of the other-side beam members 1B to the opposing joints 4, 4 of the other suspended scaffolding F1, F1, thereby spanning the other-side beam members 1B between the joints 4, 4. By performing this operation on the joints 4 on the front and back sides in the depth direction in Figure 1, the frame 10 of the suspended scaffolding F is formed together with the beam members 1, 1 (one-side beam members 1A, 1A) of the other suspended scaffolding F1, F1 that face each other in the left-right direction in Figure 1. Thus, in this embodiment, the suspended scaffolding F shares joints 4 and beam members 1 (one-side beam members 1A) with the other suspended scaffolding F1.

[0107] Furthermore, two workers, holding the ends of the first support member 5 from the floorboards of the other suspended scaffolding F1, F1, insert the pins 51c of the first mounting portion 51 into the holes 1a4 provided in the upper chord members 1a of the opposing side beam members 1A, 1A of the other suspended scaffolding F1, F1, thereby installing the first support member 5 so as to span between the side beam members 1A, 1A. By repeating this process for each hole 1a4, three first support members 5 are spanned between the side beam members 1A, 1A. At this time, since the first mounting portion 51 of the first support member 5 is connected to the upper chord member 1a of the side beam member 1A, the workers can safely span between the side beam members 1A, 1A without leaning over.

[0108] Furthermore, the two workers, from the floorboards of the other suspended scaffolding F1, F1, each hold the ends of the second support member 6 and connect the second mounting portion 61 to each of the opposing joints 4 in the left-right direction in Figure 1 via the connecting pin P3, and insert the pin 62c of the auxiliary mounting portion 62 into the hole 1a4 provided in the longitudinal center of the upper chord member 1a of the other side beam member 1B, thereby installing the second support member 6 parallel to the first support member 5. By performing this work for the joints 4, 4 on the near side and the joints 4, 4 on the far side in the depth direction of Figure 1, the second support member 6 is installed between each other side beam member 1B and the first support member 5.

[0109] Finally, the floorboard 30 is placed on the first support portion 50 of the first support member 5 and the second support portion 60 of the second support member 6, and the first baseboards 8L, 8R and the second baseboards 9L, 9R are installed inside the frame 10 along the outer edge of the floorboard 30, thereby assembling the suspended scaffolding F shown in Figure 2.

[0110] Furthermore, it is preferable to install the support beams 15 and the raised floor 16 on the frame 10 of the suspended scaffolding F in advance, because when performing maintenance work on the underside of the main girder 11a of the bridge 11, the work space can be easily secured simply by removing the raised floor 16 and the support beams 15 from the frame 10.

[0111] Furthermore, the method of assembling the suspended scaffolding F is not limited to the method described above. For example, the suspended scaffolding F assembled on the ground or on the deck slab 11b of the bridge 11 may be suspended from the bridge 11 using heavy machinery such as a crane, and then other suspended scaffolding F1 may be connected to the suspended scaffolding F. Also, although the suspended scaffolding F is positioned below the main girder 11a of the bridge 11 in Figure 1, the suspended scaffolding F may be positioned in a location that does not face the main girder 11a vertically.

[0112] As described above, the suspended scaffolding F of this embodiment comprises a frame 10 formed by connecting the ends of a plurality of beam members 1 having upper chord members 1a and lower chord members 1b arranged in a vertical line, a chain 2 as a suspension member for suspending the frame 10, and a floor structure 3 having a floor plate 30 connected to the frame 10 and positioned inside the frame 10 and at least below the upper end of the upper chord member 1a, wherein the lower end of the floor structure 3 is positioned at a height at least equal to or greater than the lower end of the lower chord member 1b.

[0113] In the suspended scaffolding F configured in this way, the position of the floorboard 30 can be lowered without lowering the position of the lower end of the suspended scaffolding F. Therefore, even if the position of the floorboard 30 is lowered, the height from the lower end of the suspended scaffolding F to the road or the surface of water such as a river or the sea remains unchanged.

[0114] Therefore, even if the frame 10 of the suspended scaffolding F is raised to a level that allows large vehicles or ships to pass underneath, sufficient working space can be secured between the floor plate 30 and the underside of the bridge 11. Also, even if the position of the floor plate 30 is lowered, the height of the lower end of the suspended scaffolding F does not change, so the suspended scaffolding F does not obstruct the passage of ships, etc. Therefore, it is not necessary to raise the suspended scaffolding F every time a large vehicle or ship passes by.

[0115] Furthermore, in the suspended scaffolding F of this embodiment, the floor structure 3 has at least one first support member 5 that spans between one-sided beam members 1A, 1A, which are beam members 1, 1 facing each other, and has a first support portion 50 that supports the floorboard 30. In the suspended scaffolding F configured in this way, the height position of the floorboard 30 can be set by the height position of the first support portion 50. Furthermore, the load-bearing strength of the suspended scaffolding F can be arbitrarily set by increasing or decreasing the number of first support portions 50 that support the floorboard 30. However, if the floorboard 30 has sufficient load-bearing strength on its own, the floor structure 3 may be structured to directly connect the floorboard 30 to a portion located below the upper chord member 1a inside the frame 10, for example, the lower chord member 1b.

[0116] Furthermore, in the suspended scaffolding F of this embodiment, the lower end of the floor structure 3 is aligned horizontally with the lower end of the lower chord member 3b. With the suspended scaffolding F configured in this way, the position of the floor plate 30 can be lowered to the maximum extent possible without changing the height from the lower end of the suspended scaffolding F to the road or the water surface such as a river or the sea. Therefore, the working space between the underside of the bridge 11 and the floor plate 30 can be made as wide as possible without changing the height of the lower end of the suspended scaffolding F. However, the position of the lower end of the floor structure 3 does not need to be aligned horizontally with the lower end of the lower chord member 3b, as long as it is above the lower end of the lower chord member 3b and the floor plate 30 is positioned below the upper chord member 3a.

[0117] Furthermore, in the suspended scaffolding F of this embodiment, the first support member 5 has a first support portion 50 extending horizontally and first attachment portions 51 extending upward from each end of the first support portion 50, with their upper ends detachably connected to the upper chord member 1a. In the suspended scaffolding F configured in this way, since the first attachment portions 51 are connected to the upper chord member 1a, even if the first support portion 50 is positioned below the upper chord member 1a, workers can safely span the first support member 5 between opposing beam members 1, 1 without leaning out. However, the first support member 5 may also be connected to a portion of the beam member 1 other than the upper chord member 1a, for example, the lower chord member 1b, and spanned between opposing beam members 1, 1.

[0118] Furthermore, in the suspended scaffolding F of this embodiment, the frame 10 is formed in a rectangular shape in plan view by having four joints 4 that connect the ends of four beam members 1. The beam member 1 across which the first support member 5 is placed in the frame 10 is designated as one side beam member 1A, and the remaining beam member 1 is designated as the other side beam member 1B. The floor structure 3 has a second support member 6 positioned parallel to the first support member between the first support member 5 and the other side beam member. The second support member 6 has a second support portion 60 that extends horizontally and is positioned at the same height as the first support portion 50 to support the floor plate 30, and second attachment portions 61 provided at the ends of the second support portion 60 and detachably connected to the joints 4.

[0119] In the suspended scaffolding F configured in this way, in addition to the first support member 5 that spans between the one side beam members 1A, 1A, a second support member 6 that supports the floorboard 30 can be placed close to the other side beam member 1B inside the frame 10 using the joint 4, thereby increasing the load capacity of the floorboard 30. If the load capacity of the floorboard 30 is sufficient with only the first support member 5, the second support member 6 may be omitted. Furthermore, if it is possible to connect the first support member 5 near the end of the one side beam member 1A, the first support member 5 may be placed between the ends of the one side beam members 1A, 1A instead of the second support member 6.

[0120] Furthermore, in the suspended scaffolding F of this embodiment, the floor structure 3 has first baseboards 8L and 8R that rise from the outer edge of the floorboard 30. The first baseboards 8L and 8R have a lateral closing plate portion (vertical piece 80b and connecting plate portion 81a) that rises from the outer edge of the floorboard 30 and closes the gap between the upper chord 1a and the lower chord 1b of the beam member 1, and an upper closing plate portion 81b provided at the upper end of the lateral closing plate portion that closes the gap between the floorboard 30 and the beam member 1. In the suspended scaffolding F configured in this way, the gap between the upper chord 1a and the lower chord 1b of the beam member 1 and the gap between the floorboard 30 and one side beam member 1A are closed by the first baseboards 8L and 8R, so that tools and the like do not fall through these gaps. However, the first baseboards 8L and 8R do not necessarily have an upper closing plate portion 81b.

[0121] Furthermore, the suspended scaffolding F of this embodiment is equipped with a locking device 7 provided on the first mounting portion 51 that can fix the first mounting portion 51 in a connected state to the upper chord member 1a. The first mounting portion 51 has an upright portion 51a extending upward from the end of the first support portion 50, a protruding portion 51b that protrudes from the upright portion 51a toward the beam member 1 and abuts against the upper surface of the upper chord member 1a, and a pin 51c that protrudes from the lower end of the protruding portion 51b and is inserted from above into a hole 1a4 provided in the upper chord member 1a. The locking device 7 is equipped with a locking device 7 that is connected to the protruding portion 51b and The device includes a locking piece 70 that is arranged in parallel and movable parallel to the projection 51b, and together with the projection 51b, is able to sandwich the bottom 1a2, which is at least a part of the upper chord member 1a, and a fixing means 71 that can fix the locking piece 70 so as not to move relative to the upright portion 51a, wherein the locking piece 70 is movable between a position that sandwiches the bottom 1a2, which is at least a part of the upper chord member 1a, together with the projection 51b, and a position that does not face the bottom 1a2, which is the aforementioned part of the upper chord member 1a, in the vertical direction.

[0122] In the suspended scaffolding F configured in this way, the locking device 7 consists only of a locking piece 70 and a fixing means 71, thus reducing the number of parts. Furthermore, in the locking device 7 of this embodiment, the first support member 5 can be carried while the locking piece 70 and the fixing means 71 remain attached to the first mounting portion 51, so there is no need to attach the locking device 7 to the first support member 5 when connecting the first support member 5 to the beam member 1. Note that the above-described configuration of the locking device 7 is just one example, and the configuration of the locking device 7 is not particularly limited as long as the first mounting portion 51 can be fixed while connected to the upper chord member 1a. Also, the locking device 7 may be omitted.

[0123] Furthermore, the suspended scaffolding F of this embodiment includes a support beam 15 that is detachably spanned between the upper chord members 1a, 1a of opposing beam members 1 and positioned above the floorboard 30, and a raised floor 16 installed on the support beam 15. With the suspended scaffolding F configured in this way, even when the floorboard 30 is installed below the upper chord members 1a of the beam members 1, the raised floor 16 can be detachably installed above the floorboard 30. Therefore, when workers perform maintenance work at lower positions on the bridge 11, they can use the floorboard 30 as a work platform, and when performing maintenance work at higher positions on the bridge 11, they can use the raised floor 16 as a work platform. However, if workers do not perform maintenance work at locations that cannot be reached even when using the floorboard 30 as a work platform, the support beam 15 and the raised floor 16 may be omitted.

[0124] Furthermore, in the suspended scaffolding F of this embodiment, the frame 10 is formed in a rectangular shape in plan view by connecting the ends of four beam members 1, and each first attachment portion 51 of the first support member 5 is connected to the upper chord 1a of one side beam member 1A that is opposed to one side in one direction in the frame 10, and the support beam 15 is spanned between the upper chords 1a, 1a of the other side beam member 1B that are opposed to one side in the frame 10 in a direction perpendicular to the other direction.

[0125] With the suspended scaffolding F configured in this way, the first support member 5 and the support beam 15 are spanned between other beam members 1,1, thus preventing assembly errors such as connecting the first support member 5 where the support beam 15 should be connected. Furthermore, even if the first mounting portion 51 of the first support member 5 is connected to the upper chord member 1a of one side beam member 1A using a hole 1a4 provided in the upper chord member 1a of one side beam member 1A, the end of the support beam 15 can be connected to the upper chord member 1a of the other side beam member 1B using the hole 1a4 provided in the upper chord member 1a of the other side beam member 1B. Therefore, it is not necessary to provide a separate hole in the upper chord member 1a of the beam member 1 for connecting the end of the support beam 15, in addition to the hole 1a4 for connecting the first mounting portion 51 of the first support member 5. However, the first support member 5 and the support beam 15 may also be spanned between the upper chord members 1a,1a of the same beam members 1,1.

[0126] Furthermore, the suspended scaffolding F of this embodiment is equipped with second baseboards 9L and 9R which are arranged along the inner circumference of the frame 10 and close the gap between the upper chord 1a and lower chord 1b of the other side beam member 1B, and recesses 91b are formed at the upper ends of the second baseboards 9L and 9R at positions corresponding to the part where the end of the support beam 15 is connected to the upper chord 1a of the other side beam member 1B.

[0127] With the suspended scaffolding F configured in this way, the recess 91b prevents the support beam 15 from interfering with the second baseboards 9L and 9R. Therefore, even if the second baseboards 9L and 9R are installed on the inner circumference side of the frame 10, the support beam 15 can be spanned between the other side beam members 1B and 1B, respectively.

[0128] Although preferred embodiments of the present invention have been described in detail above, modifications, alterations, and changes are permitted as long as they do not deviate from the scope of the claims. [Explanation of Symbols]

[0129] 1...Beam member, 1A...One-side beam member, 1B...Other-side beam member, 2...Chain (hanging member), 3...Floor structure, 4...Joint, 5...First support member, 6...Second support member, 7...Locking device, 8L, 8R...First baseboard (baseboard), 9L, 9R...Second baseboard (baseboard), 10...Frame, 15...Support beam, 16...Raised floor, 30...Floorboard, 50...First support part, 51...First mounting part, 51a...Upright part, 51b...Protruding part, 51c...Pin, 60...Second support part, 61...Second mounting part, 70...Locking piece, 71...Fixing means, 81b...Upper closing plate part, 91b...Recess

Claims

1. A frame formed by connecting the ends of multiple beam members having upper chord members and lower chord members arranged vertically, A suspension member for suspending the aforementioned frame, The floor structure comprises a floor plate connected to the frame and positioned inside the frame and at least below the upper end of the upper chord member, The lower end of the floor structure is positioned at a height at least equal to or greater than the lower end of the lower chord member. A suspended scaffold characterized by the following features.

2. The floor structure has at least one first support member, which is spanned between the opposing beam members and has a first support portion that supports the floor slab. The suspended scaffolding according to feature 1.

3. The lower end of the floor structure is aligned horizontally with the lower end of the lower chord member. The suspended scaffolding according to feature 1.

4. The first support member has a first support portion extending horizontally and a first mounting portion extending upward from each end of the first support portion, the upper ends of which are detachably connected to the upper chord member. The suspended scaffolding according to feature 2.

5. The frame has four joints connecting the ends of the four beam members and is formed in a rectangular shape in plan view. The beam member across which the first support member in the frame is stretched is designated as one side beam member, and the remaining beam member is designated as the other side beam member. The floor structure has a second support member positioned parallel to the first support member between the first support member and the other side beam member, The second support member has a second support portion that extends horizontally and is positioned at the same height as the first support portion to support the floorboard, and a second mounting portion provided at the end of the second support portion and detachably connected to the joint. The suspended scaffolding according to feature 2.

6. The floor structure has a baseboard that rises from the outer edge of the floorboard, The baseboard has a lateral closing plate portion that rises from the outer edge of the floorboard and closes the gap between the upper chord and the lower chord of the beam member, and an upper closing plate portion provided at the upper end of the lateral closing plate portion and closing the gap between the floorboard and the beam member. The suspended scaffolding according to feature 1.

7. The first mounting portion is provided with a locking device that can fix the first mounting portion in a connected state to the upper chord member, The first mounting portion has an upright portion extending upward from the end of the first support portion, a projection portion that protrudes from the upright portion toward the beam member and abuts against the upper surface of the upper chord member, and a pin that protrudes from the lower end of the projection portion and is inserted from above into a hole provided in the upper chord member. The locking device is A locking piece is positioned parallel to the projection and movable parallel to the projection, and together with the projection, it can sandwich at least a portion of the upper chord member and face that portion; The locking piece has a fixing means that can fix it immovably to the upright portion, The locking piece is movable between a position where it clamps the portion of the upper chord together with the protrusion and a position where it does not face the portion of the upper chord in the vertical direction. The suspended scaffolding according to feature 4.

8. A support beam is detachably spanned between the upper chord members of the opposing beam members and is located above the floorboard, The system includes a raised floor installed on the aforementioned support beam. A suspended scaffold according to any one of claims 1 to 7.

9. The frame is formed in a rectangular shape in plan view by connecting the ends of the four beam members. Each first mounting portion of the first support member is connected to the upper chord of the beam member facing each other in one direction within the frame, The support beam is spanned between the upper chords of the beam members that are facing each other in the frame in a direction perpendicular to the one direction. The suspended scaffolding according to claim 8, referencing feature 4.

10. The frame is provided with a plurality of baseboards arranged in a line along its inner circumference to close the gap between the upper chord and the lower chord of the beam member, A recess is formed at the upper end of the baseboard at a position corresponding to the portion where the end of the support beam is connected to the upper chord of the beam member. The suspended scaffolding according to feature 9.

Images