JP7540649B2 - Suspended scaffolding - Google Patents

Description

This invention relates to suspended scaffolding.

Conventionally, when carrying out maintenance work such as inspection and repair work on bridge girders, suspended scaffolding that is suspended from the bridge girders has been used.

For example, a suspended scaffolding includes a suspension member, such as a suspension chain or a suspension wire, one end of which is fixed to the underside of the bridge girder, and a floor plate suspended by the suspension member (see, for example, Patent Document 1). With such a suspended scaffolding, workers can carry out maintenance work on the bridge girder from the floor plate.

Utility Model Application Publication No. 2018-025060

However, when using conventional suspended scaffolding on the girders of a bridge with a road underneath, if you try to leave enough working space between the girders and the deck, the height from the road to the deck becomes too low, making it impossible for vehicles to travel on the road.

As a result, when using conventional suspended scaffolding to carry out maintenance work on bridge girders of a bridge with a road underneath, it is necessary to either move the deck closer to the girders to reduce the work space, or close the road to traffic during the work period.

However, if the working space between the deck and the bridge girder becomes smaller, it becomes more difficult for workers to work, which can lead to reduced work efficiency and repairs being missed. In addition, if the road is closed during the work period, it cannot be used, which reduces convenience for road users.

The present invention aims to provide a suspended scaffold that can improve work efficiency while minimizing the inconvenience to road users.

In order to achieve the above object, the suspended scaffolding of the present invention is characterized in that it is suspended and supported by a pair of opposing bridge girders, and is provided with a floor plate arranged in a transverse direction across the bridge length direction of the bridge girders at a position opposite the lower end of the bridge girders, and a lifting device capable of raising and lowering the floor plate. With this configuration, the floor plate can be moved closer to and farther from the bridge girders by the lifting device.

In addition, the suspended scaffolding of the present invention includes a pair of scaffolding devices arranged at positions sandwiching each of the bridge girders in the transverse direction and having a scaffold plate and a suspension member for suspending the scaffold plate, the floor plate is spanned between the scaffolding devices, and the lifting device lifts and lowers the scaffolding devices to lift and lower the floor plate. With this configuration, a worker can carry out work on the side of the bridge girder from above the scaffold plate of the scaffolding device, and the worker can move safely to the floor plate through the scaffold plate.

The suspended scaffolding of the present invention is provided with a support member having a support rod fixed to each bridge girder and arranged along the bridge length direction of the bridge girder, and the suspension member is provided with an upper hook that positions the floor plate in a working position where a worker can work on the floor plate when it is hooked on the support rod, and a lower hook that positions the floor plate in a storage position close to the bridge girder when it is hooked on the support rod, which are arranged vertically, and the lower hook is connected to the suspension member so as to be rotatable in the vertical direction and protrudes toward the bridge girder side, and is restricted from rotating when pushed up from below at the protruding position protruding toward the bridge girder side, but is allowed to rotate when pushed down from above. With this configuration, when the floor plate is raised from the working position to the storage position, the lower hook can be easily hooked on the support rod, so that the floor plate in the working position can be easily positioned to the storage position.

In addition, in the suspended scaffolding of the present invention, the support member may include a fixing device fixed to a handrail provided integrally above the bridge girder along the bridge length direction, a pair of holding pieces provided on the fixing device and holding the support rod, and a guide piece disposed between the scaffolding device and the bridge girder and abutting against the suspension member, and the suspension member may be inserted between the pair of holding pieces. With this configuration, the scaffolding device can be safely attached from the inside of the handrail and can be prevented from interfering with the bridge girder when the scaffolding device is raised or lowered.

In addition, the suspended scaffolding of the present invention has a pair of cross members that are provided at the lower end of each scaffolding device along the bridge length direction of the bridge girder and face each other, and the floor plate is spanned between the pair of cross members, and floor hooks that are provided at the lower end of the floor plate at positions facing the cross members and hooked onto the cross members, and the floor hooks allow the cross members to move laterally when viewed from the axial direction of the cross members. With this configuration, the scaffolding devices can be raised and lowered one by one, making it easy to raise and lower the floor plate.

In addition, in the suspended scaffolding of the present invention, the suspension member has a pair of vertical struts and a plurality of horizontal members that are spanned between the pair of vertical struts at a predetermined interval, and is formed in a ladder shape . With this configuration, the suspension member can be used as a ladder, so there is no need for a ladder to descend to the floor board.

In addition, in the suspended scaffold of the present invention, the lifting device may be a lever hoist or a chain block, one end of the lever hoist or the chain block may be attached to the bridge girder, and the other end of the lever hoist or the chain block may be attached to the scaffold device. With this configuration, since one end of the lever hoist or the chain block is attached to the bridge girder, the suspended scaffold can be supported by the lever hoist or the chain block even if the support member comes off the bridge girder.

In addition, in the suspended scaffolding of the present invention, the other end of the lever hoist or the chain block may be attached to a position spaced apart from the bridge girder of the scaffolding device. With this configuration, it is possible to suppress lateral swaying of the floor plate spanning between the scaffolding devices.

The suspended scaffolding of the present invention may also have one or more handrail posts that are removably fixed to the floorboards, and multiple handrail rods that are extendable and extend between the hanging member and the handrail post or between adjacent handrail posts. With this configuration, the axial length of the handrail rod can be adjusted by extending and retracting the handrail rod, so that the axial length of the handrail rod can be adjusted according to the transverse length of the bridge.

The suspended scaffolding of the present invention can improve work efficiency while minimizing inconvenience to road users.

FIG. 2 is a front view showing the suspended scaffolding of this embodiment installed on a bridge girder. FIG. 2 is a side view of the suspended scaffolding shown in FIG. 1 . FIG. 2 is a partially enlarged front view of FIG. 4A is an enlarged front view of an upper hook provided on the scaffolding device of the suspended scaffolding of this embodiment, and FIG. 4B is a side view of FIG. 4A, with a part cut away, as viewed from the side. 5A is an enlarged front view of a lower hook provided in the scaffolding device of the suspended scaffolding of this embodiment, and FIG. 5B is a side view of FIG. 5B, with a part cut away, as viewed from the side. (A) is a front view showing a state in which a support member is fixed to a handrail, (B) is a front view showing a state in which a scaffolding device is attached to the support member, and (C) is a front view showing a state in which a floor plate is spanned between cross members of the scaffolding device and a handrail post and a handrail rod are attached to the floor plate. 1A is a front view of the suspended scaffolding showing a state in which one scaffolding device is raised, and FIG. 1B is a front view of the suspended scaffolding showing a state in which both scaffolding devices are raised and the floor plates are arranged in the storage position.

The present embodiment will be described below with reference to the drawings. The same reference numerals are used throughout the drawings to indicate the same parts.

The suspended scaffolding 1 of this embodiment is used for maintenance work such as inspection and repair work of the bridge girders 10 of bridge B. As shown in FIG. 1, bridge B comprises a number of piers (not shown), a pair of bridge girders 10, 10 on the left and right in the figure that are bridged between adjacent piers and face each other, handrails H that are integrally provided above each bridge girder 10 along the bridge length direction that is the extension direction of the bridge girders 10, and a floor F that is bridged and fixed between the pair of bridge girders 10, 10.

In detail, as shown in FIG. 1, the bridge girder 10 of this embodiment is composed of an I-shaped steel section having a web 10a extending along the length of the bridge and horizontal plate-like flange portions 10b and 10c connected to the upper and lower ends of the web 10a, respectively, and extending along the web 10a.

As shown in Figures 1 and 2, the handrail H of this embodiment comprises a number of posts Ha that rise vertically from the bridge girder 10 and are arranged at a predetermined interval along the length of the bridge, and horizontal cross bars Hb with a rectangular cross section that are spanned across the upper ends of the posts Ha and extend along the length of the bridge, and are integrally connected to the bridge girder 10.

As shown in Fig. 1, the suspended scaffolding 1 of this embodiment includes a floor plate 2 that is arranged in a direction crossing the bridge length direction of the bridge girder 10 (hereinafter referred to as the "transverse direction") at a position opposite the lower end of the bridge girder 10, and a lifting device that can raise and lower the floor plate 2. Therefore, the suspended scaffolding 1 of this embodiment can move the floor plate 2 in the up and down direction in the figure by using the lifting device to move it closer to or farther from the bridge girder 10.

The components of the suspended scaffolding 1 of this embodiment are described in detail below. As shown in FIG. 1, the suspended scaffolding 1 of this embodiment includes a support member 4 fixed to a handrail H that is integrally provided on each bridge girder 10, and a pair of scaffolding devices 5, 5 supported by each support member 4 and positioned to sandwich each bridge girder 10 in a transverse direction that crosses the bridge length direction of the bridge girder 10, and the floor plate 2 is spanned between the pair of scaffolding devices 5, 5.

The support member 4 of this embodiment includes a support rod 4a arranged along the bridge length direction of the bridge girder 10, and a fixing device 4b that fixes the support rod 4a to the handrail H. Specifically, as shown in Figures 1 and 3, the fixing device 4b has an opposing piece 4c that faces the inside of the crossbar Hb of the handrail H (the other handrail H side), a guide piece 4d that faces the outside of the crossbar Hb of the handrail H, a connection piece 4e that connects the upper ends of the opposing piece 4c and the guide piece 4d in the figure, a bolt shaft 4f that penetrates the opposing piece 4c and is screwed to the opposing piece 4c so as to be axially movable, and a spacer 4g that is fixed to the opposing piece 4c side of the guide piece 4d. Then, with the cross bar Hb positioned between the bolt shaft 4f and the spacer 4g, the bolt shaft 4f is rotated and moved toward the guide piece 4d in the manner of a feed screw, so that the cross bar Hb is clamped between the bolt shaft 4f and the spacer 4g, and the fixing device 4b is fixed to the handrail H.

As shown in Figures 2 and 3, a pair of holding pieces 4h, 4h are provided on the guide piece 4d side of the upper end of the connection piece 4e, standing from the upper end of the connection piece 4e and facing each other in the extension direction of the cross bar Hb. Each holding piece 4h is plate-shaped, and a support rod 4a is bridged between the pair of holding pieces 4h, 4h. Note that the support rod 4a in this embodiment is formed in a cylindrical shape, but the shape of the support rod 4a is just one example, and it may be formed in a square prism shape, for example.

In this way, the support rod 4a in this embodiment is fixed to the bridge girder 10 via the handrail H by the fixing device 4b, and is arranged along the bridge length direction of the bridge girder 10. However, the configuration of the fixing device 4b described above is only one example, and is not limited to the above configuration as long as the support rod 4a can be fixed to the bridge girder 10.

Next, the scaffolding device 5 will be described in detail. As shown in Figs. 1 and 2, the scaffolding device 5 in this embodiment includes a pair of hanging members 6, 6 that are arranged facing each other in the bridge length direction of the bridge girder 10 and supported by support rods 4a, and a scaffolding plate 7 that is suspended between the lower ends of the pair of hanging members 6, 6 and supported by the hanging members 6.

Specifically, as shown in FIG. 1, the hanging member 6 is configured in a ladder shape with a pair of vertical supports 6a, 6b facing each other in the transverse direction of the bridge girder 10, and a horizontal member 6c that is suspended vertically between the pair of vertical supports 6a, 6b at a specified interval, as shown in FIG. 1. In this way, the hanging member 6 can be used as a ladder when the worker moves to the scaffolding board 7, so the installation of a ladder can be omitted. Note that in this embodiment, the vertical supports 6a, 6b and the horizontal member 6c are formed with a square cross section, but they may also be formed with a cylindrical cross section.

Of the pair of vertical pillars 6a, 6b, the vertical pillar 6a arranged on the bridge girder 10 side (hereinafter referred to as the "bridge girder side vertical pillar 6a") is provided with an upper hook 8 that protrudes toward the bridge girder 10 side and is hooked onto the support rod 4a.

In detail, as shown in FIG. 4(A), the upper hook 8 in this embodiment has a rectangular plate-shaped fixed piece 8a that extends along the bridge girder side vertical support 6a and is fixed to the bridge girder side vertical support 6a, and a substantially L-shaped hook piece 8b that protrudes downward from the bridge girder 10 side end of the fixed piece 8a.

As shown in FIG. 4(B), the fixing piece 8a in this embodiment is fixed to the bridge girder side vertical support 6a by a bolt 11 inserted into a pair of upper and lower holes 6d, 6d that penetrate the bridge girder side vertical support 6a in a direction intersecting with the cross member 6c and a pair of upper and lower holes (not shown) provided in the fixing piece 8a, and a nut 12 screwed onto the bolt 11.

The support members 4 are installed on the crosspieces Hb of each handrail H at the same intervals as the pair of hanging members 6, 6 are arranged, as shown in FIG. 2. Therefore, the scaffolding device 5 is supported on the support rod 4a by hooking the hook pieces 8b of each upper hook 8 onto the support rod 4a of each support member 4.

At this time, when the upper hook 8 is hooked onto the support rod 4a, the bridge girder side vertical support 6a is inserted between the holding pieces 4h, 4h, and the holding pieces 4h restrict the movement of the scaffolding device 5 in the bridge length direction of the bridge girder 10. Therefore, in this embodiment, when the upper hook 8 is hooked onto the support rod 4a, even if the scaffolding device 5 is blown by the wind, the holding pieces 4h of the scaffolding device 5 restrict the movement of the bridge girder 10 in the bridge length direction, and the scaffolding device 5 is prevented from falling off the support member 4.

As shown in FIG. 3, each bridge girder-side vertical support 6a abuts against a guide piece 4d that faces the outside of the horizontal crosspiece Hb of the handrail H. Here, in this embodiment, the guide piece 4d is positioned closer to the scaffolding device 5 than the outer ends of each flange portion 10b, 10c of the bridge girder 10. Therefore, the scaffolding device 5 abuts only against the guide piece 4d and does not come into contact with the bridge girder 10.

The structure of the upper hook 8 in this embodiment is merely an example, and is not particularly limited as long as it can be hooked onto the support rod 4a. In addition, the fixing piece 8a of the upper hook 8 may be fixed to the bridge girder-side vertical support 6a by a method other than bolt and nut connection.

As shown in Figs. 1 and 3, each bridge girder-side vertical support 6a is provided with a lower hook 9 that is disposed below the upper hook 8 and can be hooked onto the support rod 4a. As shown by the solid line in Fig. 5(A), the lower hook 9 in this embodiment includes a main body 9a that extends along the bridge girder-side vertical support 6a and has an upper end that is connected to the bridge girder-side vertical support 6a so as to be rotatable in the vertical direction, and a hook portion 9b that protrudes diagonally downward from the upper end of the main body 9a toward the bridge girder 10 and has a U-shaped groove 9c on the lower side.

In detail, as shown in FIG. 5(B), the lower hook 9 is connected to the bridge girder side vertical support 6a so as to be rotatable in the vertical direction by a support shaft 13 inserted into a hole 6e that penetrates the bridge girder side vertical support 6a in a direction intersecting with the cross member 6c and a hole (not shown) provided at the upper end of the main body 9a, and a nut 14 that is screwed onto the support shaft 13. This allows the lower hook 9 in this embodiment to rotate around the support shaft 13 as a fulcrum.

In addition, as shown in FIG. 5(B), the lower hook 9 in this embodiment is provided with a plate-shaped stopper portion 9d that stands vertically from the edge of the lower end of the main body portion 9a on the side opposite the hook portion toward the bridge girder-side vertical support 6a.

Furthermore, in a natural state where only gravity acts, the lower hook 9 assumes a position in which the hook portion 9b protrudes toward the bridge girder 10, as shown by the solid line in Figure 5(A).

As shown in Figure 3, when the scaffolding device 5 is moved upward with the lower hook 9 positioned below the support rod 4a, the lower hook 9 is pushed by the support rod 4a, rotates, and retracts toward the girder-side vertical support 6a, so the lower hook 9 does not get in the way of the upward movement of the scaffolding device 5. Then, when the scaffolding device 5 is moved downward after the lower hook 9 is above the support rod 4a, the lower hook 9 gets caught on the support rod 4a and the stopper portion 9d abuts against the anti-girder side of the girder-side vertical support 6a, restricting the rotation of the lower hook 9.

As shown in FIG. 5(B), the lower end of the main body 9a and the bridge girder vertical support 6a are provided with pin holes 6f, 9e that face each other when the lower hook 9 is in its natural state, and an L-shaped lock pin 15 can be inserted into each pin hole 6f, 9e to prevent the lower hook 9 from rotating in the protruding position. A lock pin 16 is hinged to the tip of the lock pin 15 to prevent it from coming out of each pin hole 6f, 9e.

Going back to the above, each end of the scaffolding board 7 is provided with a hook (not shown) that can be hooked onto the cross member 6c of the hanging member 6, so that it can be spanned between any pair of opposing cross members 6c, 6c. In this embodiment, as shown in FIG. 1, the scaffolding board 7 is hooked onto the hook between the lowest cross members 6c, 6c of the hanging member 6, so that the scaffolding board 7, which functions as a work scaffold, spans between the lower ends of a pair of hanging members 6, 6.

In this embodiment, as shown in FIG. 1, a reinforcing scaffold board 7A having the same structure as the scaffold board 7 is also hung between the cross members 6c, 6c in the second row from the top of the hanging member 6. However, this reinforcing scaffold board 7A functions not as a work scaffold but as a reinforcing member connecting the upper end side of the scaffold device 5. In other words, when the reinforcing scaffold board 7A is hung between the cross members 6c, 6c arranged above, the scaffold device 5 becomes box-shaped as a whole, so that the strength of the scaffold device 5 is increased. In addition, although not shown, the reinforcing scaffold board 7A is provided with a hatch door, so that even if the reinforcing scaffold board 7A is hung between the cross members 6c, 6c arranged above, the worker can move to the scaffold board 7 hung between the cross members 6c, 6c in the lowest row by opening the hatch door.

The number and position of the scaffolding boards 7 are not particularly limited. For example, when performing maintenance work on the side of the bridge girder 10, the scaffolding boards 7 may be installed according to the location where the work will be performed.

Although not described in detail, baseboards 17 are installed on the hanging members 6 so as to surround the outer periphery of each scaffolding board 7, 7A except for the side facing the girder 10, preventing tools and the like from falling from the scaffolding boards 7, 7A. Furthermore, as shown in FIG. 2, truss-shaped reinforcing frames 18 that reinforce the scaffolding device 5 are attached in a vertical line between the vertical supports 6b, 6b of the pair of vertical supports 6a, 6b of the pair of hanging members 6, 6, which are located on the opposite side to the girder.

Although not described in detail, as shown in FIG. 1, a clamp 19 is detachably connected to the bridge girder-side vertical support 6a at a position facing the lower flange portion 10c of the bridge girder 10. The lower end of the scaffolding device 5 is fixed to the bridge girder 10 by clamping the lower flange portion 10c with this clamp 19.

As shown in Figures 1 and 2, a cross member 20 is spanned across the lower ends of the opposing bridge girder-side vertical struts 6a of each scaffolding device 5 along the bridge length direction of the bridge girder 10. Therefore, the cross members 20 provided on each scaffolding device 5 are arranged to face each other in the transverse direction of the bridge girder 10. A floor plate 2, which will be described later, is spanned between the cross members 20, 20.

Specifically, as shown in FIG. 1, a C-shaped cross-section support bracket 21 that opens downward is provided at the lower end of each bridge girder-side vertical support 6a. Then, with a cross member 20 made of a pipe material inserted inside each support bracket 21 that faces each other in the bridge length direction of the bridge girder 10, a bolt (not shown) is inserted so as to penetrate the support bracket 21 and the cross member 20 laterally, and a nut (not shown) is screwed onto the bolt and tightened, so that the cross member 20 is suspended across the lower ends of each bridge girder-side vertical support 6a, 6a that faces each other in the bridge length direction of the bridge girder 10.

The configuration in this embodiment in which the cross member 20 is spanned across the lower ends of the bridge girder-side vertical supports 6a, 6a that face each other in the bridge length direction of the bridge girder 10 is merely an example, and is not limited to the above-mentioned configuration. In this embodiment, the cross member 20 is made of a pipe material, but this is merely an example, and it does not have to be a pipe material. For example, the cross member 20 may be solid, or may be formed with a square cross section.

Next, the floor panel 2 of this embodiment will be described. As shown in FIG. 1, the floor panel 2 of this embodiment is a plate material whose width is longer than the width between the cross members 20, 20. In addition, at the lower end of the floor panel 2, a number of floor hooks 22 are arranged along the bridge length direction of the bridge girder 10 at positions facing each cross member 20 when the floor panel 2 is spanned between the cross members 20, 20. The floor hooks 22 are hooked onto each cross member 20, so that the floor panel 2 is spanned between the cross members 20, 20.

As shown in FIG. 1, the floor hook 22 of this embodiment is formed with a U-shaped cross section, comprising a pair of vertical pieces 22a, 22a facing each other in the transverse direction of the bridge girder, and a bottom piece 22b that connects the upper ends of the vertical pieces 22a, 22a in the figure and is connected to the lower end of the floor board 2. The distance between the vertical pieces 22a, 22a is set to be longer than the diameter of the cross member 20. Therefore, the floor hook 22 of this embodiment is allowed to move laterally when viewed from the axial direction of the cross member 20 when the floor board 2 is spanned between the cross members 20, 20.

In addition, in this embodiment, by inserting a pin 23 that penetrates the tip (lower end in Figure 1) of each of the opposing vertical pieces 22a, 22a while the floor hook 22 is hooked onto the cross member 20, the floor board 2 is prevented from floating up and falling off the hanging member 6.

In addition, in this embodiment, multiple floor hooks 22 are arranged in a line along the bridge length direction of the bridge girder 10, but the floor hooks 22 may be configured as a single member that extends continuously along the bridge length direction of the bridge girder 10. Note that the structure of the floor hooks 22 in this embodiment is an example and is not limited to the configuration described above.

Returning to FIG. 1, when viewed from the bridge length direction of the bridge girder 10, bottomed cylindrical support brackets 31 into which handrail posts 30 are removably inserted are provided at the center of each of the front and back ends of the floorboard 2. Furthermore, extendable handrail rods 32 are arranged vertically and span between the handrail posts 30 and the bridge girder-side vertical supports 6a of each scaffolding device 5. Therefore, in this embodiment, the entire periphery of the floorboard 2 can be surrounded by the handrail rods and the scaffolding device 5, allowing workers to work safely on the floorboard 2.

The handrail rod 32 in this embodiment has a telescopic structure that includes a cylindrical one-side rod 32a and a cylindrical other-side rod 32b that is slidably inserted into the one-side rod 32a. Therefore, the handrail rod 32 can be extended and retracted by sliding the other-side rod 32b axially within the one-side rod 32a.

The outer periphery of the tip of the rod 32a on one side is provided with an L-shaped first bracket 33 that can be detachably attached to the handrail support 30. On the other hand, the tip of the rod 32b on the other side is provided with a second bracket 34 that can be detachably attached to the bridge girder side vertical support 6a. As shown in FIG. 1, the handrail rod 32 on the right side in the figure is arranged so that the first bracket 33 faces upward, and the handrail rod 32 on the left side in the figure is arranged so that the first bracket 33 faces downward. In this way, even if the handrail rod 32 on the right side in the figure and the handrail rod 32 on the left side in the figure, which are at the same height, are connected to a single handrail support 30 from both the left and right sides, the first bracket 33 of the handrail rod 32 on the right side in the figure and the first bracket 33 of the handrail rod 32 on the left side in the figure do not interfere with each other. Therefore, in this embodiment, the handrail rod 32 on the right side in the figure and the handrail rod 32 on the left side in the figure can be installed at the same height position.

Although not described in detail, as shown in FIG. 1, a baseboard 35 is detachably connected to the upper end of the floorboard 2, spanning between the lower end of the handrail support 30 and the lower end of each bridge girder-side vertical support 6a, preventing tools and the like from falling from the floorboard 2. In addition, the baseboard 35 in this embodiment is formed with a telescopic structure and is extendable and retractable, so that the length of the baseboard 35 can be adjusted according to the distance between the bridge girder-side vertical supports 6a, 6a.

Next, the lifting device of this embodiment will be described in detail. In this embodiment, as shown in FIG. 1, a known lever hoist 3 that can manually operate an operating lever to wind up and lower a chain 3a is used as the lifting device, and the lever hoist 3 is installed between each bridge girder 10 and each scaffolding device 5. Therefore, in this embodiment, each scaffolding device 5 is suspended and supported by the lever hoist 3 so that it can be raised and lowered.

In detail, the lever hoist 3 has a holding block 3c that holds the gear around which the chain 3a is wound and has an upper hook 3b, and a lower hook 3d that is provided at the tip of the chain 3a. The upper hook 3b provided at the upper end, which is one end of the lever hoist 3, is hooked to a hanging wire 40 hung on a crosspiece Hb of a handrail H that is integrally connected to the bridge girder 10, and the lower hook 3d provided at the lower end, which is the other end of the lever hoist 3, is hooked to an attachment piece 41 attached to a cross member 6c of the hanging member 6 of the scaffolding device 5, so that the scaffolding device 5 is suspended and supported so as to be able to rise and fall by the lever hoist 3. Therefore, when each scaffolding device 5 is raised and lowered by the lever hoist 3, the floor plate 2 spanning between each scaffolding device 5, 5 is also raised and lowered together with the scaffolding device 5.

In this embodiment, one end of the lever hoist 3 is attached to the handrail H that is integrally connected to the bridge girder 10, but it may also be attached to a support member 4 that is fixed to the handrail H. However, if one end of the lever hoist 3 is attached to the handrail H, even if the support member 4 becomes detached from the handrail H, the suspended scaffolding 1 can be suspended and supported by the lever hoist 3, preventing the suspended scaffolding 1 from falling.

In addition, in this embodiment, as shown in FIG. 1, the mounting piece 41 is attached to the cross member 6c at a position away from the bridge girder 10, so the lever hoist 3 is installed at an angle with its lower end in the figure facing away from the bridge girder 10. This causes the lever hoist 3 to exert a force pulling the scaffolding device 5 in an oblique direction. If the pulling force of the lever hoist 3 is resolved, the scaffolding device 5 is subjected to an upward force and a lateral force pulling it toward the bridge girder 10.

Therefore, when the lever hoist 3 is installed at an angle in this manner, a lateral force is also applied to the scaffolding device 5, pulling it toward the bridge girder 10, suppressing the lateral swing of the floor plate 2 spanning between the scaffolding devices 5, 5. However, the lever hoist 3 may also be installed vertically.

The lifting device is not limited to the lever hoist 3, but may be a heavy machine such as a chain block, winch, or crane. However, when using a lever hoist or chain block as the lifting device, the work can be done by human power, so there is no need to prepare a power source.

Next, the installation method of the suspended scaffolding 1 of this embodiment will be described in detail. First, as shown in FIG. 6(A), the worker clamps the cross rails Hb of the handrail H with the fixing device 4b with the support rods 4a facing the outside of the bridge girder 10, and fixes the support members 4 in a line, two at a time, to the cross rails Hb of each handrail H. Then, the support rods 4a are positioned so that they protrude outward from the handrail H and are aligned along the bridge length direction of the bridge girder 10.

Next, the worker lifts up the scaffolding device 5 that has been assembled in advance, and hooks the upper hook 8 of the scaffolding device 5 onto the support rod 4a. The scaffolding device 5 is then temporarily fixed to the support member 4 in a position that sandwiches each bridge girder 10 in the transverse direction, as shown in FIG. 6(B).

The worker then uses the aerial work vehicle to attach clamps 19 to each scaffolding device 5 from below the bridge B, and clamps the lower flange portion 10c of the bridge girder 10 with the clamps 19 to connect the underside of each scaffolding device 5 to the bridge girder 10. The worker then spans the floorboards 2 between the cross members 20, 20 from above the aerial work vehicle, and inserts pins 23 so that they penetrate the tips of the vertical pieces 22a of the floor hooks 22. Furthermore, as shown in Figure 6 (C), the handrail posts 30, handrail rods 32, and baseboards 35 are installed on the floorboards 2.

Finally, the worker loops the hoisting wire 40 around the crosspiece Hb of each handrail H, then hooks the upper end hook 3b of the lever hoist 3 onto the hoisting wire 40, and hooks the lower end hook 3d of the lever hoist 3 onto the mounting piece 41 of the scaffolding device 5. Then, as shown in Figure 1, the lever hoist 3 is installed between the handrail H, which is integrally provided on each bridge girder 10, and each scaffolding device 5.

When the suspended scaffolding 1 is thus installed on a pair of bridge girders 10, 10 with the upper hooks 8 of each scaffolding device 5 hooked onto the support rods 4a of each support member 4, the floor plate 2 is positioned at a position (hereinafter referred to as the "work position") that allows a worker to work on the floor plate 2. The distance between the floor plate 2 placed at the work position and the lower end of the bridge girder 10 may be set arbitrarily as long as sufficient work space can be secured between the floor plate 2 and the bridge girder 10.

Next, as shown in Figure 1, in the suspended scaffold 1 with the floor plate 2 installed at the work position, the procedure for raising each scaffold device 5 with the lever hoist 3 as a lifting device and bringing the floor plate 2 close to just below the bridge girder 10 will be described.

First, the worker removes the handrail support 30, handrail rod 32, baseboard 35, and clamp 19 attached to the floor plate 2 from the aerial work vehicle. After that, as shown in Figure 7(A), the worker operates the operating lever of one of the lever hoists 3 on the right side of the figure to wind up the chain 3a. Then, the scaffolding device 5 on the right side of Figure 7(A) rises while abutting against the guide piece 4d, and the upper hook 8 comes off the support rod 4a, and instead the lower hook 9 gets caught on the support rod 4a.

In detail, when the scaffolding device 5 is raised, the support rod 4a comes into contact with the upper end of the hook portion 9b of the lower hook 9, and the lower hook 9 is pushed from above by the support rod 4a. The lower hook 9 is then pushed down by the support rod 4a, and the lower hook 9 swings from the protruding position (position shown by the solid line in FIG. 5(A)) to the non-protruding position (position shown by the dashed line in FIG. 5(A)) where the hook portion 9b does not protrude toward the bridge girder 10, allowing the lower hook 9 to move above the support rod 4a.

Then, the lower hook 9, which automatically returns to its original protruding position in a natural state, is hooked onto the support rod 4a. At this time, the stopper portion 9d of the lower hook 9 abuts against the vertical strut 6a on the bridge girder side, restricting rotation, so the lower hook 9 will not come off the support rod 4a even if a force is applied to push it up from below. Furthermore, in this state, the lower hook 9 is locked in the protruding position by inserting the lock pin 15 into the pin hole 9e of the lower hook 9 and the pin hole 6f of the vertical strut 6a on the bridge girder side.

As shown in FIG. 7(A), when the scaffolding device 5 on the right side of the figure is raised, the position of the cross member 20 on the right side of the figure becomes higher than the position of the cross member 20 on the left side of the figure. Here, the distance between the cross members 20, 20 is longer when the heights of the cross members 20 are different than when the heights of the cross members 20 are the same, but the floor hook 22 in this embodiment has a width that allows the cross member 20 to move laterally when viewed from the axial direction of the cross member 20.

As a result, each cross member 20 is allowed to move in the width direction (the direction in which the vertical pieces 22a, 22a face each other) within each floor hook 22, so as shown in FIG. 7(A), by lifting only the scaffolding device 5 on the right side of the figure, even if the distance between the cross members 20, 20 becomes long, the scaffolding devices 5 can be lifted one at a time even while the floor board 2 is still suspended between the cross members 20, 20.

Next, the scaffolding device 5 on the left side of the figure is raised in the same manner as the scaffolding device 5 on the right side of the figure, and the lower hook 9 is hooked onto the support rod 4a. Then, as shown in Figure 7 (B), both scaffolding devices 5 are raised to the same height position, and the deck plate 2 is positioned in a position immediately adjacent to the bridge girder 10 (hereinafter referred to as the "storage position"). "Immediately adjacent to the bridge girder 10" here refers to a position close enough to the bridge girder 10 without touching it, and the distance from the bridge girder 10 is not particularly limited.

Although not shown, when the floorboard 2 arranged in the storage position is to be lowered to the working position, the scaffolding device 5 is lifted to an extent that the lower hook 9 comes off the support rod 4a, and the lower hook 9 is rotated and pushed toward the bridge girder side vertical support 6a so that the support rod 4a and the lower hook 9 do not interfere with each other, and then the scaffolding device 5 is lowered with the lever hoist 3. The order in which the scaffolding devices 5 are raised is not particularly limited, and the scaffolding device 5 on the left side in the figure may be raised first, and then the scaffolding device 5 on the right side in the figure may be raised.

As described above, the suspended scaffolding of this embodiment is a suspended scaffolding 1 suspended and supported by a pair of opposing bridge girders 10, 10, and includes a floor plate 2 arranged in a transverse direction across the bridge length of the bridge girders 10 at a position opposite the lower end of the bridge girders 10, and a lifting device (lever hoist 3) capable of raising and lowering the floor plate 2.

According to this configuration, the floor plate 2 can be moved closer to or farther from the bridge girder 10 by raising and lowering it with the lifting device. Therefore, by lowering the floor plate 2 and moving it away from the bridge girder 10 during work, sufficient work space can be secured between the floor plate 2 and the bridge girder 10, improving work efficiency. On the other hand, by raising the floor plate 2 and moving it closer to the bridge girder 10 while not working, there is no need to close the road even if a road is laid below the bridge girder 10.

In other words, in this embodiment, the road is closed only during work and can be lifted at other times. Therefore, for example, by lowering the floor plate 2 during times of low traffic volume to carry out work, and then raising the floor plate 2 to lift the road closure during times of high traffic volume, it is possible to minimize the inconvenience to road users.

Therefore, the suspended scaffolding 1 of this embodiment can improve work efficiency while minimizing the inconvenience to road users.

The transverse direction of the bridge girder 10 is not limited to a direction perpendicular to the bridge length direction of the bridge girder 10, but also includes a direction diagonally across the bridge length direction of the bridge girder 10.

The suspended scaffolding 1 of this embodiment is equipped with a pair of scaffolding devices 5, 5 that are arranged at positions sandwiching each bridge girder 10 in the transverse direction and have a scaffolding plate 7 and a suspension member 6 that suspends the scaffolding plate 7, and the floor plate 2 is spanned between the scaffolding devices 5, 5, and the lifting device lifts and lowers the scaffolding device 5 to lift and lower the floor plate 2.

With this configuration, a worker can stand on the scaffolding plate 7 of the scaffolding device 5 to perform work on the side of the bridge girder 10, and can also move safely to the floor plate 2 via the scaffolding plate 7. However, the scaffolding device 5 may be omitted, and the floor plate 2 may be raised and lowered directly by the lifting device.

The suspended scaffolding 1 of this embodiment is equipped with a support member 4 having support rods 4a fixed to each bridge girder 10 and arranged along the bridge length direction of the bridge girder 10. The suspension member 6 is provided with upper hooks 8 that, when hooked onto the support rods 4a, position the floor board 2 in a working position that allows a worker to work on the floor board 2, and lower hooks 9 that, when hooked onto the support rods 4a, position the floor board 2 in a storage position that is immediately adjacent to the bridge girder 10. The lower hooks 9 are connected to the suspension member 6 so as to be rotatable in the vertical direction and protrude toward the bridge girder 10. At the protruding position protruding toward the bridge girder 10, rotation is restricted when pushed up from below, but rotation is permitted when pushed down from above.

According to this configuration, when the lifting device is used to raise the floorboard 2 from the working position to the storage position, the lower hook 9 is pushed from above by the support rod 4a and rotates from the protruding position, allowing the support rod 4a to pass under the lower hook 9. The lower hook 9 then automatically returns to the protruding position, allowing the lower hook 9 to be hooked onto the support rod 4a. At this time, the lower hook 9 positioned in the protruding position is restricted from rotating when pushed up from below, so while it is hooked onto the support rod 4a, the lower hook 9 does not rotate and does not come off the support rod 4a.

Therefore, in this embodiment, when the floor panel 2 is raised from the working position to the storage position, the lower hook 9 can be easily hooked onto the support rod 4a, so that the floor panel 2 in the working position can be easily positioned in the storage position.

The structure of the lower hook 9 in this embodiment shown in Figure 5 is just one example, and the structure is not particularly limited as long as rotation is restricted when pushed up from below at the protruding position protruding toward the bridge girder 10, and rotation is permitted when pushed down from above. Also, in this embodiment, the lower hook 9 is designed to automatically return to the protruding position in its natural state, but it may also be designed to be manually switched between the protruding position and the non-protruding position.

In addition, in the suspended scaffolding 1 of this embodiment, the support member 4 includes a fixing device 4b that is fixed to a handrail H that is integrally provided above the bridge girder 10 along the bridge length direction, a pair of holding pieces 4h, 4h that are provided on the fixing device 4b and hold the support rod, and a guide piece 4d that is positioned between the scaffolding device 5 and the bridge girder 10 and abuts against the suspended member 6, and the suspended member 6 is inserted between the pair of holding pieces 4h, 4h.

With this configuration, the support member 4 having the support rod 4a that supports the scaffolding device 5 is fixed to the handrail H, so the worker can safely install the scaffolding device 5 from inside the handrail H. Furthermore, since the guide piece 4d is disposed between the bridge girder 10 and the scaffolding device 5, it is possible to prevent the scaffolding device 5 from interfering with the bridge girder 10 when the scaffolding device 5 is raised or lowered.

In addition, because the hanging member 6 is inserted between the holding pieces 4h, 4h, the movement of the scaffolding device 5 in the bridge length direction is restricted. Therefore, the hanging member 6 always abuts against the guide piece 4d when the scaffolding device 5 is raised or lowered. Furthermore, because the movement of the scaffolding device 5 in the bridge length direction is restricted, the scaffolding device 5 is prevented from falling off the support member 4.

In this embodiment, the support member 4 is fixed to the bridge girder 10 via a handrail H that is integral with the bridge girder 10, but it may also be fixed directly to the bridge girder 10.

The suspended scaffolding 1 of this embodiment also has a pair of cross members 20 that are arranged at the lower end of each scaffolding device 5 along the bridge length direction of the bridge girder 10, facing each other, and across which the floor plate 2 is spanned, and floor hooks 22 that are arranged at positions facing each cross member 20 at the lower end of the floor plate 2 and hook onto the cross members 20, and the floor hooks 22 allow the cross members 20 to move laterally when viewed in the axial direction of the cross members 20.

With this configuration, each cross member 20 is allowed to move in the width direction within each floor hook 22, so that by raising and lowering only one of the scaffolding devices 5, even if the distance between the cross members 20, 20 becomes long, the scaffolding devices 5 can be raised and lowered one at a time even while the floor plate 2 is still suspended between the cross members 20, 20. Therefore, with the suspended scaffolding 1 of this embodiment, there is no need to raise and lower both scaffolding devices 5, 5 at the same time, which makes it easier to raise and lower the floor plate 2.

In addition, in the suspended scaffolding 1 of this embodiment, the suspended member 6 has a pair of vertical supports 6a, 6b and a number of horizontal members 6c that are spanned at a predetermined interval between the pair of vertical supports 6a, 6b, and is formed in a ladder shape. With this configuration, the suspended member 6 can be used as a ladder, so there is no need for a ladder to descend to the floorboard 2.

In addition, in the suspended scaffolding 1 of this embodiment, the lifting device is a lever hoist 3, one end of which is attached to the bridge girder 10 and the other end of which is attached to the scaffolding device 5. With this configuration, since one end of the lever hoist 3 is attached to the bridge girder 10, even if the support member 4 comes off the bridge girder 10, the lever hoist 3 can support the suspended scaffolding 1. Furthermore, since the lever hoist 3 can be operated by human power, there is no need to prepare a power source. Note that the lifting device may be a chain block instead of the lever hoist 3, and even if a chain block is used, there is no need to prepare a power source since the operation can be performed by human power.

In addition, in the suspended scaffolding 1 of this embodiment, the other end of the lever hoist 3 is attached to the scaffolding device 5 at a position spaced apart from the bridge girder 10. With this configuration, the lever hoist 3 exerts an upward force on the scaffolding device 5 and a lateral force pulling it toward the bridge girder 10, thereby suppressing the lateral swing of the floor plate 2 spanning between the scaffolding devices 5, 5. Even if the lifting device is a chain block instead of the lever hoist 3, the lateral swing of the floor plate 2 can be similarly suppressed.

The suspended scaffolding 1 of this embodiment also has a handrail post 30 that is detachably fixed to the floorboard 2, and multiple handrail rods 32 that are extendable and retractable and span between the hanging member 6 and the handrail post 30. With this configuration, the axial length of the handrail rod 32 can be adjusted by extending and retracting the handrail rod 32, so that the axial length of the handrail rod 32 can be adjusted according to the transverse length of the bridge B. Note that, although the number of handrail posts 30 is one in this embodiment, there may be multiple, and when there are multiple handrail posts 30, the handrail rods 32 are also spanned between the handrail posts 30, 30.

The above describes in detail the preferred embodiment of the present invention, but it is understood that modifications, variations and changes can be made without departing from the scope of the claims.

Reference Signs List 1: Suspended scaffolding, 2: Floor plate, 3: Lever hoist (lifting device), 4: Support member, 4a: Support rod, 4b: Fixing device, 4d: Guide piece, 4h: Holding piece, 5: Scaffolding device, 6: Suspension member, 6a, 6b: Vertical supports, 6c: Horizontal member, 8: Upper hook, 9: Lower hook, 10: Bridge girder, 20: Horizontal member, 22: Floor hook, 30: Handrail support, 32: Handrail rod

Claims (7)

In a suspended scaffold that is suspended and supported by a pair of opposing bridge girders,
A pair of scaffolding devices are arranged at positions sandwiching each of the bridge girders in a transverse direction crossing the bridge length direction of the bridge girders, and have a scaffolding plate and a hanging member for hanging the scaffolding plate;
A floor plate disposed in the transverse direction at a position opposite to the lower end of the bridge girder and spanning between the scaffolding devices ;
A lifting device capable of lifting and lowering the floor panel by lifting and lowering the scaffolding device ;
A support member having a support rod fixed to each bridge girder and arranged along the bridge length direction of the bridge girder ,
The hanging member is provided with upper hooks arranged vertically, the upper hooks being hooked onto the support rods to position the floor panel at a working position that enables a worker to work on the floor panel, and lower hooks being hooked onto the support rods to position the floor panel at a storage position that is immediately adjacent to the bridge girder,
The lower hook is connected to the hanging member so as to be rotatable in the vertical direction and protrudes toward the bridge girder side, and at a protruding position protruding toward the bridge girder side, rotation is restricted when pushed up from below, but rotation is permitted when pushed down from above.
A suspended scaffold characterized by: In a suspended scaffold that is suspended and supported by a pair of opposing bridge girders,
A pair of scaffolding devices are arranged at positions sandwiching each of the bridge girders in a transverse direction crossing the bridge length direction of the bridge girders, and have a scaffolding plate and a hanging member for hanging the scaffolding plate;
A floor plate disposed in the transverse direction at a position opposite to the lower end of the bridge girder and spanning between the scaffolding devices;
A lifting device capable of lifting and lowering the floor panel by lifting and lowering the scaffolding device;
A pair of cross members are provided at the lower ends of the scaffolding devices along the bridge length direction of the bridge girder, facing each other, and across which the floor plate is spanned;
a floor hook provided at a position facing each of the cross members at the lower end of the floor plate and hooked onto the cross members;
The floor hook allows the cross member to move laterally when viewed in the axial direction of the cross member.
A suspended scaffold characterized by: In a suspended scaffold that is suspended and supported by a pair of opposing bridge girders,
A pair of scaffolding devices are arranged at positions sandwiching each of the bridge girders in a transverse direction crossing the bridge length direction of the bridge girders, and have a scaffolding plate and a hanging member for hanging the scaffolding plate;
A floor plate disposed in the transverse direction at a position opposite to the lower end of the bridge girder and spanning between the scaffolding devices;
A lifting device capable of lifting and lowering the floor plate by lifting and lowering the scaffolding device,
The hanging member has a pair of vertical posts and a plurality of horizontal members that are spanned at predetermined intervals between the pair of vertical posts, and is formed in a ladder shape.
A suspended scaffold characterized by: The support member is
A fixing device fixed to a handrail integrally provided above the bridge girder along the bridge length direction;
A pair of holding pieces provided on the fixing device to hold the support rod;
A guide piece is disposed between the scaffolding device and the bridge girder and abuts against the hanging member,
The suspended scaffolding according to claim 1 , wherein the suspension member is inserted between the pair of holding pieces. The lifting device is a lever hoist or a chain block,
One end of the lever hoist or the chain block is attached to the bridge girder,
The suspended scaffolding according to any one of claims 2 to 4 , characterized in that the other end of the lever hoist or the chain block is attached to the scaffolding device. The suspended scaffolding according to claim 5 , characterized in that the other end of the lever hoist or the chain block is attached to a position spaced apart from the bridge girder of the scaffolding device. One or more handrail posts removably fixed to the floorboard;
The suspended scaffolding according to any one of claims 1 to 6 , characterized in that it comprises a plurality of handrail rods which are extendable and extend between the hanging member and the handrail post or between adjacent handrail posts.

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