Mobile lifting scaffolding

Abstract

To provide a lifting and lowering movable scaffold that can be applied to maintenance work for bridge across railroads having a short separation distance from a trolley line and easily move in a ridge direction of the bridge across railroads by avoiding an overhead line such as the trolley line, and allows passage on the bridge across railroads during the maintenance work for the bridge across railroads without requiring assembly and removal for each operation day.SOLUTION: A lifting and lowering movable scaffold has a pair of right and left rails installed along both edges of a road surface of bridge across railroads (pedestrian bridge), a pair of right and left lower movable mechanisms 3 travelling on the pair of right and left rails, a pair of right and left masts 2a erected on the lower movable mechanisms 3, a pair of right and left lifting and lowering mechanisms 4 that moves up and down along the masts 2a, a beam 2b connecting the pair of right and left lifting and lowering mechanisms 4, 4 with each other, and a pair of horizontally movable mechanisms 5, 5 that is suspended from and supported by each lifting and lowering mechanism 4 of the pair of lifting and lowering mechanisms 4, 4 and can horizontally move below the bridge across railroads (pedestrian bridge). The beam 2b is installed at a height allowing people to pass on the road surface of the bridge across railroads (pedestrian bridge Pb) even when the lifting and lowering mechanism 4 is located at a lowest height.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a mobile lifting scaffold for performing maintenance work on an overpass erected above an overhead wire. More specifically, it relates to a mobile lifting scaffold for performing maintenance work on an overpass where the separation distance between the overhead wire and the overpass is small and ordinary scaffolds such as single-pipe scaffolds, wedge scaffolds, and framework scaffolds cannot be installed in between.

Background Art

[0002] On the tracks of railways, there are overpasses, which are structures that cross the tracks in a form that straddles the overhead wires of tram railways, such as pedestrian bridges, bicycle and automobile overpasses. These overpass structures are generally steel structures combined with steel materials because they can take a large span. Therefore, such steel structures are coated with anti-rust paint, and regular maintenance work such as repainting the anti-rust paint and maintenance inspections is required.

[0003] However, performing maintenance work on such overpasses is extremely dangerous and impossible during train operation, so it has to be done within the limited time after the last train. Moreover, the temporary scaffold for performing maintenance work has to be removed before the operation of the first train, and there is a problem that repair work can only be done within an extremely limited time in the suburbs of Tokyo. Furthermore, on the routes where freight trains pass, since there are trains passing through in addition to the last and first trains of ordinary vehicles, maintenance work can only be carried out on predetermined dates and times determined in advance after application.

[0004] When performing such maintenance work on overpasses, conventionally, it has been carried out using a high-altitude worker on a rail vehicle that can run on the tracks. However, rail vehicles can only be transported to the site from positions where roads and railway lines intersect, such as level crossings. It takes time just to transport the rail vehicle to the work location after the last train, and the time available for the maintenance work itself is reduced, resulting in a long working period and inevitably higher repair costs.

[0005] Regarding technologies related to temporary scaffolding used for maintenance work on such overpasses, Patent Document 1 discloses a temporary construction method for work scaffolding on a pedestrian bridge, and Patent Document 2 discloses a scaffolding device for railway tracks.

[0006] Patent Document 1 discloses a work scaffold for a pedestrian bridge, which consists of a pair of foldable and joined scaffolding boards 2 as a set, and multiple sets of these sets connected in one direction via horizontal members 3 to form a unit scaffold 1 that can be deployed in a long manner for the required span, suspension ropes 5 inserted through all ends of the horizontal members 3, and an operating rope 6 for deployment and folding attached to the horizontal member 3 at one end of the unit scaffold 1 (see paragraphs

[0011] to

[0027] of the specification of Patent Document 1, and Figures 1 to 8 of the drawings, etc.).

[0007] However, although the work scaffolding for pedestrian bridges described in Patent Document 1 can be installed in a short time, it cannot be directly applied to structures such as pedestrian bridges or other overpasses because the trolley wires carrying high currents are directly suspended from it, and repair work near the trolley wires cannot be performed.

[0008] Furthermore, Patent Document 2 describes a railway track scaffolding device comprising a trolley 10 that can be manually moved onto the rails, a pair of telescopic columns 13, 13 that are detachably attached to the trolley 10 and have slidably connected cylindrical members 26 made of lightweight metal material, a fluid pressure type jack for extending and retracting the telescopic columns 13, a pair of work platforms 14, 14 made of lightweight metal material attached to the upper ends of the telescopic columns 13, a closing floor plate 15 that is retractably attached to one of the work platforms 14 and closes the gap between the work platforms 14, 14, and a scaffolding board 5 that connects adjacent work platforms 14 and an attachment member 6 installed on the side column 1a of the work object 1.

[0009] However, while the railway track scaffolding device described in Patent Document 2 can indeed be installed and dismantled in a short time, it has the problem that the scaffolding must be repeatedly installed and dismantled within the few hours between the last train and the first train of the day, leaving no time to dedicate to maintenance work itself.

[0010] Furthermore, the applicant of this application proposed a movable lifting scaffold in Patent Document 3. The movable lifting scaffold described in Patent Document 3 is a movable lifting scaffold 10 having a guide mast 20, a drive unit 30 that is attached to and detached from the guide mast 20 and moves up and down when attached, and a work deck 40 that is installed on the drive unit 30 in a substantially horizontal position, wherein a drive unit 30 is attached to each of the two guide masts 20, the work deck 40 is installed so as to span across the two drive units 30, and an elongated spanning section 70 is provided which is installed in a substantially horizontal direction above the work deck 40 and moves up and down together with the work deck 40, and a lateral moving crane device 90 that moves in a substantially horizontal direction above the work deck 40 along the spanning section 70 can be installed on the spanning section 70.

[0011] The mobile lifting scaffolding described in Patent Document 3 is said to allow for easy transport and handling of heavy or large objects, eliminate the need for additional lifting equipment such as cranes, save space, and enable workers to perform tasks safely and efficiently. However, the mobile lifting scaffolding described in Patent Document 3 could not be applied to overpasses directly connected to overhead lines, including the trolley wires carrying the aforementioned high currents.

[0012] Furthermore, there are requests that pedestrian and vehicle traffic be permitted on overpasses and pedestrian bridges that cross railway lines, as mentioned above, even during maintenance work. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] Japanese Patent Publication No. 2000-96819 [Patent Document 2] Japanese Patent Publication No. 2002-12395 [Patent Document 3] Japanese Patent Publication No. 2020-33713 [Overview of the project] [Problems that the invention aims to solve]

[0014] Therefore, the present invention was devised in view of the aforementioned problems, and its purpose is to provide a movable lifting scaffold that can be applied to maintenance work on overpasses with a small distance from the trolley wire, allows for easy movement of the overpass in the longitudinal direction while avoiding overhead wires such as trolley wires, allows passage on the overpass even during maintenance work, and does not require assembly and disassembly on a daily basis. [Means for solving the problem]

[0015] The movable lifting scaffolding according to claim 1 is a movable lifting scaffolding for performing maintenance work on an overpass erected above a trolley line, comprising: a pair of left and right rails installed along both edges of the road surface of the overpass; a pair of left and right lower moving mechanisms that run on the pair of left and right rails; a pair of left and right masts erected on the lower moving mechanisms; a pair of left and right lifting mechanisms that perform an up and down movement along the masts; a beam connecting the pair of left and right lifting mechanisms; and a pair of left and right horizontal moving mechanisms suspended and supported by each of the lifting mechanisms of the pair of lifting mechanisms and capable of moving horizontally below the overpass, wherein the beam is extended to a height that allows people to pass over the road surface of the overpass even when the lifting mechanisms are at their lowest height. The pair of left and right horizontal movement mechanisms each comprises a horizontal movement body having a work platform, a slide rail is attached to the lower part of each horizontal movement body, the slide rail is slidably supported in the lifting section of the lifting mechanism, the horizontal movement bodies are configured to be slidably moved manually or electrically, and at least the support material supporting the work platform is insulated or made of insulating material. It is characterized by the following.

[0016] The movable lifting scaffolding according to claim 2 is the movable lifting scaffolding according to claim 1, wherein the lifting mechanism comprises an electric motor that rotationally drives a pinion gear, a rack that meshes with the pinion gear is formed on the mast, and the lifting mechanism moves up and down along the mast on which the rack is formed by rotationally driving the pinion gear with the electric motor.

[0017] The movable lifting scaffolding according to claim 3 is characterized in that, in the movable lifting scaffolding according to claim 1, the lower moving mechanism comprises wheels that travel on the rails and base jacks that lift and separate the wheels from the road surface of the overpass.

[0020] Claim 4 The mobile lifting scaffolding relating to the claim 1In the movable lifting scaffold according to the present invention, when maintenance work is not being carried out, the work floor is configured to be able to rise above the lower surface of the overpass.

[0021] Claim 5 The movable lifting scaffold according to claim 1 In the movable lifting scaffold according to claim

Advantages of the Invention

[0022] According to the invention according to claims 1 to 5 It can be used for the maintenance work of overpasses where the distance from the trolley wire is small and a normal scaffold cannot be assembled. It can easily move in the girder direction of the overpass while avoiding overhead wires such as trolley wires, and it is possible to pass through the overpass during maintenance work, eliminating the need for assembly and disassembly for each night-time operation when the tram is not running. Furthermore, according to the inventions of claims 1 to 5, each of the left and right horizontal movement mechanisms comprises a horizontal movement body having a work platform, a slide rail is attached to the lower part of each horizontal movement body, the slide rail is slidably supported in the lifting section of the lifting mechanism, and the horizontal movement bodies are configured to be slidably moved manually or electrically, so that a movable lifting scaffold can be easily installed between multiple trolley wires by moving over an overpass where it is not possible to erect a normal scaffold in close proximity to the trolley wire. In addition, according to the inventions of claims 1 to 5, the support material that supports the work platform is insulated or made of an insulating material, so that the problem of sparking due to residual current is eliminated and maintenance work can be carried out safely.

[0023] In particular, according to the invention according to claim 2, since the pinion gear is rotationally driven by an electric motor and moves up and down along the mast with a rack formed thereon, there is little noise, etc., and it can be lifted and lowered quietly, safely and reliably.

[0024] In particular, according to the invention according to claim 3, since it has wheels that run on rails and a base jack that lifts the wheels away from the road surface of the overpass, it can be easily moved by manpower, and when lifting and lowering with the lifting mechanism, it can be fixed with the base jack and lifted and lowered safely.

[0027] In particular, according to the invention according to claim 4 Even for an overpass close to the trolley wire, it becomes possible to energize the trolley wire without completely removing the movable lifting scaffold, and it is possible to omit part of the installation work for each night-time operation and carry out the maintenance work in a short time.

[0028] In particular, claims 5 According to the invention, the pair of horizontal moving bodies are configured so that their longitudinal ends can be connected to each other, so that the ends of the horizontal moving bodies, which have one longitudinal end as a free end, can be connected, thereby improving structural safety. 5 According to the invention, it becomes possible to pass between each work platform, improving the efficiency of maintenance work. [Brief explanation of the drawing]

[0029] [Figure 1] Figure 1 is a downward perspective view mainly showing the upper structure of a mobile lifting scaffolding according to an embodiment of the present invention. [Figure 2] Figure 2 is an overhead perspective view mainly showing the lower structure of the mobile lifting scaffolding described above. [Figure 3] Figure 3 is a downward perspective view mainly showing the left and right lower moving mechanisms of the same mobile lifting scaffolding. [Figure 4] Figure 4 is a partially enlarged perspective view mainly showing the wheels and rails of the lower moving mechanism shown above. [Figure 5] Figure 5 is a perspective view mainly showing the upper part of the gantry frame of the lifting mechanism of the mobile lifting scaffolding described above. [Figure 6] Figure 6 is an overhead perspective view mainly showing the drive unit of the lifting mechanism described above. [Figure 7] Figure 7 is a downward perspective view mainly showing the lifting section of the same lifting mechanism. [Figure 8] Figure 8 is an overhead perspective view showing the pair of horizontal movement mechanisms of the aforementioned mobile lifting scaffolding moved to the underside of the pedestrian bridge and connected to each other. [Figure 9] Figure 9 is an upward perspective view showing the horizontal movement mechanism of the same mobile lifting scaffolding extended outwards when the installation position is changed. [Figure 10] Figure 10 is a perspective view showing the same mobile lifting scaffolding installed on a pedestrian bridge, with people using the sidewalk during maintenance work. [Figure 11]Figure 11 is a perspective view showing two of the same mobile lifting scaffolding units installed on either side of a trolley wire. [Figure 12] Figure 12 is a perspective view showing the distance between the mobile lifting scaffolding and the trolley wire. [Figure 13] Figure 13 is a perspective view showing the same movable lifting scaffolding retracted to the upper underside of the overpass. [Figure 14] Figure 14 is a perspective view showing the lifting mechanism of the same mobile lifting scaffolding moving horizontally while avoiding streetlights. [Figure 15] Figure 15 is a perspective view showing the state of the mobile lifting scaffolding described above during material delivery. [Figure 16] Figure 16 is a perspective view showing the assembled state of the gantry frame of the mobile lifting scaffolding described above. [Figure 17] Figure 17 is a perspective view showing the completed assembly of the portal frame shown above. [Figure 18] Figure 18 is a perspective view showing the connection of the lifting section and horizontal movement mechanism to the gantry frame shown above. [Figure 19] Figure 19 is a perspective view showing the extension of the horizontal movement mechanism during repositioning of the same mobile lifting scaffolding. [Figure 20] Figure 20 is a perspective view showing the upward movement of the lifting mechanism during repositioning of the same mobile lifting scaffolding. [Modes for carrying out the invention]

[0030] Hereinafter, one embodiment of the mobile lifting scaffolding according to the present invention will be described in detail with reference to the drawings.

[0031] [Mobile lifting scaffolding] A movable lifting scaffold 1 according to an embodiment of the present invention will be described using Figures 1 to 9. Figure 1 is a downward perspective view mainly showing the upper structure of the movable lifting scaffold 1 according to an embodiment of the present invention, and Figure 2 is an upward perspective view mainly showing the lower structure of the movable lifting scaffold 1.

[0032] In this embodiment, we will explain using an example where the movable lifting scaffolding 1 is used as scaffolding for maintenance work on a pedestrian bridge Pb (overpass: steel structure), which is an overpass erected above the overhead lines of a railway and to which overhead lines, including the trolley wire TL carrying a large current, are directly connected. In the illustrated configuration, the distance (vertical separation distance) between the trolley wire TL and the pedestrian bridge Pb is assumed to be about 300 mm, which is a small separation distance and would prevent the installation of conventional scaffolding such as single-pipe scaffolding, wedge-type scaffolding, or frame scaffolding in between. Of course, the 300 mm separation distance is merely an example.

[0033] The term "front view" refers to the view of the movable lifting scaffolding 1 from the pedestrian bridge Pb, crossing and perpendicular to the train tracks and trolley wire TL. Furthermore, "maintenance work" refers to work including repair work such as repainting the rust-preventive coating on the steel structure of the overpass, and maintenance and inspection work necessary for carrying out repair work (the same applies hereafter).

[0034] The movable lifting scaffolding 1 according to this embodiment is a scaffolding based on a gate-shaped frame 2 that supports the weight of the entire movable lifting scaffolding 1 when viewed from the front. The movable lifting scaffolding 1 also includes a pair of left and right lower moving mechanisms 3 that travel on the walking surface (sidewalk WW) of the pedestrian bridge Pb, which are joined to the lower end of the gate-shaped frame 2, a lifting mechanism 4 that is supported by the lower moving mechanisms 3 and moves up and down along the gate-shaped frame 2, and a horizontal moving mechanism 5 that is suspended and supported by the lifting mechanism 4 and moves horizontally. Here, left and right refers to the left and right sides on either side of the sidewalk WW when moving along the sidewalk WW of the pedestrian bridge Pb, and front refers to one side when viewing the movable lifting scaffolding 1 along this sidewalk (the same applies hereinafter).

[0035] (Gate-type frame) As shown in Figures 1 and 2, the portal frame 2 consists of a pair of left and right masts 2a, 2a, each formed by joining multiple rectangular steel pipes 20 with a rectangular horizontal cross-section in the longitudinal direction, and two upper and lower beams 2b, 2b that connect the lifting mechanisms 4 described later. In this embodiment, the beams 2b are truss beams made of combined steel materials. Of course, the two upper and lower beams are not limited to truss structures, but may also be made of steel materials such as rectangular steel pipes or H-shaped steel.

[0036] Furthermore, each mast 2a has a rack 21 formed on one surface of the square steel pipe 20 (the outer surface facing the sidewalk in the illustrated configuration) that engages with the pinion gear of the lifting mechanism 4 described later, and serves as a guide mast that guides the drive unit 41 along the mast 2a. Of course, the mast according to the present invention is not limited to one in which multiple square steel pipes 20 are joined together, but may be made of other steel materials such as H-shaped steel that have a predetermined strength capable of withstanding bending stresses and the like that act during lifting operations.

[0037] Furthermore, on the four outer surfaces near the longitudinal ends of the rectangular steel pipe 20 of the mast 2a, connecting boxes 22 are provided, each being bolted to the connecting bolts 32 of the lower moving mechanism 3, which will be described later. These connecting bolts 32 and connecting boxes 22 constitute the connecting member 6.

[0038] Furthermore, a connecting member 23 equivalent to the aforementioned connecting member 6 is attached to the upper part of mast 2a, and an extension mast 2a' is configured to be connectable. Therefore, as described later, by adding the extension mast 2a' to mast 2a, the guide length of the lifting mechanism 4 can be extended to avoid obstacles such as streetlights OL (see Figures 13 and 14).

[0039] Furthermore, the portal frame 2 can accommodate overpasses of various widths simply by changing the length and width of the beam 2b to match the width of the pedestrian overpass Pb, without changing any other components. This reduces the number of parts and lowers the installation cost of the mobile lifting scaffolding 1.

[0040] (Lower movement mechanism) Next, the lower movement mechanism 3 of the mobile lifting scaffolding 1 will be described using Figures 3 and 4. Figure 3 is a downward perspective view mainly showing the left and right pair of lower movement mechanisms 3, 3 of the mobile lifting scaffolding 1 according to this embodiment, and Figure 4 is a horizontal perspective view mainly showing the wheels 33 and rails 36 of the lower movement mechanism 3.

[0041] The lower movement mechanism 3 is a pair of mechanisms provided at the lower ends of each of the left and right masts 2a, 2a of the gate-type frame 2 (see Figures 1 and 2). Furthermore, as shown in Figures 3 and 4, the lower movement mechanism 3 is based on a base frame 30 in which steel materials such as channel steel and angle steel are combined in a rectangular shape in plan view, and joints 31 that are joined to each mast 2a are formed near the centroid (center) on the plane of this base frame 30.

[0042] This base frame 30 has a rectangular shape that is narrower in the width direction of the sidewalk WW of the pedestrian bridge Pb than a normal base frame, and is designed to obstruct the passage of pedestrians walking on the sidewalk WW as little as possible.

[0043] Furthermore, the joint portion 31 has a rectangular shape similar to the outer shape of the mast 2a, and connecting bolts 32 are pivotably connected to each of the four outer surfaces of the joint portion 31. Therefore, by installing the lower moving mechanism 3 at the lower end of the mast 2a, raising the connecting bolts 32, hooking them onto the aforementioned connecting box 22 of the mast 2a, and tightening them by turning the nuts, the mast 2a and the lower moving mechanism 3 can be easily joined in a short time.

[0044] Furthermore, as shown in Figure 4, the lower moving mechanism 3 is equipped with casters 33b (wheels 33) at the four corners of the lower end of the base frame 30, allowing it to travel on the pedestrian bridge Pb. In addition, rail wheels 33a (wheels 33) for travel on rails 36 installed on the road surface of the pedestrian bridge Pb are also attached to the longitudinal ends of the base frame 30. Thus, the lower moving mechanism 3 travels on the rails 36 installed on the road surface of the pedestrian bridge Pb and on the road surface of the pedestrian bridge Pb using the wheels 33 (rail wheels 33a and casters 33b) provided on the base frame 30, making it possible to easily move it laterally along the rails 36 and the pedestrian bridge Pb by human power.

[0045] Furthermore, a total of four jack boxes 35, each fitted with a base jack 34, are attached to the long ends of the base frame 30. The mobile lifting scaffolding 1 is moved along the rails 36 installed on the sidewalk WW of the pedestrian bridge Pb using the rail wheels 33a of the lower moving mechanism 3 until it reaches both sides of the trolley wire TL. After moving to the predetermined position, the base jacks 34 are rotated to lift the wheels 33 (rail wheels 33a and casters 33b) away from the sidewalk WW, and the scaffolding is used in a fixed state where the base jacks 34 prevent movement by the wheels 33.

[0046] Reference numeral 36 in the figure indicates a cushioning material made of rubber or foamed resin, which is installed to prevent the lifting mechanism 4 and the base frame 30 from coming into contact with each other and being damaged during material transport.

[0047] (Lifting mechanism) Next, the lifting mechanism 4 of the mobile lifting scaffolding 1 will be explained using Figures 1, 2, 5 to 7. Figure 5 is a perspective view mainly showing the upper part of the gate-shaped frame 2 of the lifting mechanism 4 of the mobile lifting scaffolding 1. Figure 6 is an upward perspective view mainly showing the drive unit 41 of the lifting mechanism 4, and Figure 7 is a downward perspective view mainly showing the lifting unit 42 of the lifting mechanism 4.

[0048] As shown in Figures 1 and 2, the lifting mechanism 4 is based on the aforementioned gantry frame 2 and is provided in pairs on the left and right sides of each mast 2a. Each of these left and right pairs of lifting mechanisms 4, 4 comprises a drive unit 41 equipped with an electric motor 40 that rotates a pinion gear, and a lifting unit 42 connected to the drive unit 41, which is a lifting facility that moves up and down on the work platform described later. The drive unit 41 has the function of moving up and down along the mast 2a of the gantry frame 2.

[0049] As shown in Figures 5 to 7, the drive unit 41 has an electric motor 40, which rotates a pinion gear (not shown) and engages the pinion gear with the aforementioned rack 21 formed on the mast 2a, thus performing the main function of the lifting mechanism 4 for raising and lowering along the mast 2a.

[0050] An upper stage 43 is provided above each drive unit 41, which serves as an entrance / exit for boarding from the pedestrian bridge Pb and as a passageway for moving between the lifting unit 42 and the lifting unit 42. Handrails 44 are installed around this upper stage 43 to prevent falls.

[0051] Furthermore, a guard fence 45 is provided around the mast 2a above the upper stage 43 to prevent workers from accidentally coming into contact with the rack 21 on the upper stage 43 while the electric motor 40 is in operation. Reference numeral 46 in the figure indicates a control panel 46 (operation panel) for controlling the electric motor 40.

[0052] As shown in Figure 6, the lifting mechanism 4 detects the handrail Ph of the pedestrian bridge Pb using sensors, etc., and is controlled by the control panel 46 to automatically stop at a position where it does not come into contact with or interfere with the handrail Ph of the pedestrian bridge Pb.

[0053] Furthermore, the entrance door 47 shown in Figure 7 can be locked and unlocked at will using an electromagnetic valve or the like, and is configured to prevent unauthorized persons or workers from unnecessarily entering the upper stage 43.

[0054] The lifting section 42 is a rectangular tubular part formed by the combination of steel materials and the like that suspended and supported by the aforementioned drive section 41, and is a lifting facility mainly consisting of a vertically extending lifting ladder 48 that connects the upper stage 43 and the work platform of the horizontal movement mechanism 5.

[0055] Since this lifting section 42 may be installed in close proximity to the trolley wire TL through which a large current flows, it is preferable that it be insulated or made of insulating material. This is because it eliminates the problem of sparks caused by residual current, allowing maintenance work to be carried out safely.

[0056] Furthermore, the construction standards stipulate that construction work involving high-voltage and extra-high-voltage equipment should be carried out with all live circuits within the scope of the work de-energized. Therefore, work performed in close proximity to the trolley wire is carried out with the power supply shut off. As an exception, work can be carried out without shutting off the power supply if a minimum clearance distance is maintained. The standard specifies a minimum clearance distance of 1.2m (1200mm) for conventional lines with 1500V DC, and as an exception to the clearance distance, if heavy machinery other than mobile cranes is fully protected with limiters, the clearance can be reduced to 0.5m. However, due to the risk of sparks from residual current, this is extremely dangerous, so currently, all circuits are shut off and construction is carried out with a minimum clearance of 0.5m. For this reason, maintenance work on overpasses is carried out at night with the power supply shut off and a clearance distance of 500mm from the trolley wire TL maintained.

[0057] Furthermore, insulation treatment refers to the process of insulating a highly conductive substrate by forming a film with extremely low conductivity. Specifically, this can be exemplified by ceramic spraying, which involves spraying ceramics such as alumina onto metal materials such as steel. Other insulation treatments include "electrostatic powder coating," which involves adhering powder coating to the object to be coated using static electricity, and then heating it to a high temperature to create a coating film.

[0058] Furthermore, a rail support member 49 is attached to the lower end of the lifting ladder 48 of the lifting section 42, which slides freely to support the slide rail of the work platform of the horizontal movement mechanism 5 described later (see Figures 8 and 9).

[0059] (Horizontal movement mechanism) Next, the horizontal movement mechanism 5 of the mobile lifting scaffolding 1 will be explained using Figures 8 and 9. Figure 8 is an upward perspective view showing the pair of horizontal movement mechanisms 5 of the mobile lifting scaffolding 1 moved below the pedestrian bridge Pb and connected to each other, and Figure 9 is an upward perspective view showing the horizontal movement mechanism 5 pulled outwards when the mobile lifting scaffolding 1 is moved from its installation position.

[0060] The horizontal movement mechanism 5 is a pair of symmetrical mechanisms supported by the lifting section 42 of the aforementioned lifting mechanism 4, and each includes a horizontal movement body 51 having a work platform 50 that moves horizontally in a direction perpendicular to the walking path of the pedestrian bridge Pb (width direction).

[0061] This work platform 50 and horizontal moving body 51 are maintenance work scaffolding with a rectangular shape in plan view, with a longitudinal length of approximately 3m. Around the work platform 50, there are two levels of handrails 52 to prevent falls and a baseboard 53 to prevent materials from falling.

[0062] Furthermore, an aluminum slide rail 54 is attached to the lower part of each horizontal moving body 51, and this slide rail 54 is slidably supported by the rail support member 49 of the lifting section 42 of the lifting mechanism 4. As a result, the horizontal moving body 51 can be slidably moved relative to the lifting section 42 manually or electrically, and as described later, the horizontal moving body 51 with a work platform 50 can be set up next to the trolley wire TL during nighttime maintenance work. In addition, if necessary, the horizontal moving body 51 can be moved upward from the underside of the pedestrian bridge Pb to maintain a distance of 1200 mm or more from the trolley wire TL (see Figure 13).

[0063] As shown in Figures 2, 8, and 11, the pair of horizontal moving bodies 51 can be connected at their longitudinal ends by a connecting section 55 having a work platform, and are configured to allow movement between each work platform 50 via the connecting section 55. Furthermore, the horizontal moving mechanism 5, like the beam 2b of the portal frame 2, can be adapted to overpasses of various widths simply by changing the length of the connecting section 55 to match the width of the pedestrian bridge Pb, without changing any other configurations, thereby reducing the number of parts and lowering the installation cost of the mobile lifting scaffolding 1.

[0064] Furthermore, instead of attaching a dedicated component to this connecting section 55, it is also acceptable to simply lay scaffolding planks (for example, wooden scaffolding planks) between the spaced-apart work platforms 50 and connect the handrails 52 with ropes or the like. This is because it allows passage between the work platforms 50 and also provides fall prevention facilities.

[0065] [How to use a mobile lifting scaffolding] Next, the method of using the movable lifting scaffolding 1 according to an embodiment of the present invention will be explained using Figures 10 to 20. An example will be given of using the movable lifting scaffolding 1 as scaffolding for repairing a pedestrian bridge Pb (steel structure) that is erected above the overhead lines of a railway and to which overhead lines including a trolley wire TL carrying a large current are directly connected. Figure 10 is a perspective view showing the movable lifting scaffolding 1 installed on the pedestrian bridge Pb and pedestrians riding bicycles on the sidewalk WW during maintenance work. Figure 11 is a perspective view showing two movable lifting scaffoldings 1,1 installed on either side of the trolley wire TL when performing maintenance work around the trolley wire TL. Figure 12 is a perspective view showing the distance between the movable lifting scaffolding 1 and the trolley wire.

[0066] (During work) When performing periodic maintenance work such as repainting rust-preventive paint and inspections on the pedestrian bridge Pb, which is an example of an overpass erected above the trolley wire TL, the power supply is stopped at night or when no trains are passing, as shown in Figures 10 to 12, and the horizontal movement mechanisms 5 of the movable lifting scaffolding 1 are connected below the underside of the pedestrian bridge Pb while the trolley wire TL is not energized.

[0067] When performing maintenance work in areas not near the trolley wire TL, as shown in Figure 10, each mobile lifting scaffold 1 is used independently. Workers board the upper stage 43 from the walkway WW, descend using the lifting ladder 48, and move to the work platform 50 of the horizontal movement mechanism 5 to perform the maintenance work.

[0068] Furthermore, when the trolley wire TL is energized during the daytime and trains are passing, maintenance work is generally not performed. However, as described later, simply moving the mobile lifting scaffolding 1 out of a radius of 500 mm from the trolley wire TL eliminates the need to dismantle and remove it during nighttime working hours, as with conventional scaffolding. Also, if necessary, when a distance of 1200 mm or more is required from the trolley wire TL, the working platform 50 and horizontal moving body 51 of the horizontal movement mechanism 5 of the mobile lifting scaffolding 1 can be moved to the upper underside of the pedestrian bridge Pb, as shown in Figure 13. This makes it possible to energize the trolley wire TL without completely moving the mobile lifting scaffolding 1, allowing maintenance work to be performed in a short time by omitting some of the installation work required for each nighttime operation. Figure 13 is a perspective view showing the mobile lifting scaffolding 1 moved to the upper underside of the pedestrian bridge Pb.

[0069] As shown in Figure 10, the movable lifting scaffolding 1 is based on a gate-type frame 2, which is a gate-type structure with increased rigidity achieved by connecting a pair of left and right masts 2a, which are twin masts, to a beam 2b. Therefore, even when the movable lifting scaffolding 1 is installed on the pedestrian bridge Pb, a space of 3m or more in height can be secured. In other words, even when the lifting mechanism 4 is at its lowest height, the beam 2b is stretched across the road surface of the pedestrian walkway WW on the pedestrian bridge Pb at a height that allows people to pass. For this reason, even when performing maintenance work using the movable lifting scaffolding 1 at night, it does not obstruct the passage of cyclists or pedestrians. Furthermore, even during daytime train operations, the movable lifting scaffolding 1 can be moved to the end of the pedestrian bridge Pb, eliminating the need to completely remove the movable lifting scaffolding 1 from the pedestrian bridge Pb. Thus, the need to assemble and dismantle temporary scaffolding for each nighttime maintenance operation, as in the past, is eliminated.

[0070] (During assembly) The procedure for assembling the mobile lifting scaffolding 1 on the pedestrian bridge Pb will be explained using Figures 15 to 18. Figure 15 is a perspective view showing the state of the mobile lifting scaffolding 1 when materials are being brought in. Figure 16 is a perspective view showing the assembled state of the gantry frame 2, and Figure 17 is a perspective view showing the completed assembly state of the gantry frame 2. Finally, Figure 18 is a perspective view showing the connection of the lifting section 42 and the horizontal movement mechanism 5 to the gantry frame 2.

[0071] As shown in Figure 15, first, the materials for the mobile lifting scaffolding 1 are transported using a crane CL or the like, with the first stage of the square steel pipe 20 of the mast 2a connected to the lower moving mechanism 3 mentioned above, and the drive unit 41 equipped with the electric motor 40 of the lifting mechanism 4 attached to the first stage of the square steel pipe 20.

[0072] Subsequently, as shown in Figure 16, the second and third rectangular steel pipes 20 are sequentially connected to the first rectangular steel pipe 20, extending up to the mast 2a and extension mast 2a'. At the same time, the drive units 41,41 of the pair of lifting mechanisms 4,4 attached to the pair of masts 2a,2a are connected by upper and lower beams 2b,2b to construct the gate-type frame 2. The guard fence 45 is also installed at the same time. The rectangular steel pipes 20 are joined to each other using the aforementioned joining members 6.

[0073] Then, as shown in Figure 17, the casters 33b of the lower moving mechanism 3 are used to rotate the gantry frame 2 to which the drive unit 41 is attached, so that the beam 2b of the gantry frame 2 is perpendicular to the direction of travel of the sidewalk WW, and the movable lifting scaffolding 1 is fixed in place. Simultaneously with this work, a pair of rails 36 are installed along both edges of the pedestrian bridge Pb next to the sidewalk WW, and the rail wheels 33a of the lower moving mechanism 3 are placed on these rails 36 (see Figures 3 and 4).

[0074] Subsequently, as shown in Figure 18, the lifting section 42 of the lifting mechanism 4 and the horizontal movement mechanism 5 attached to the lifting section 42 are connected to the drive section 41 of the gantry frame 2 to which the drive unit 41 is mounted.

[0075] Next, as shown in Figure 2, the movable lifting scaffolding 1 is installed by horizontally moving the horizontal movement mechanism 5 inward in the direction of the arrow in the figure and connecting the pair of left and right horizontal movement mechanisms 5 with the aforementioned connecting part 55. In this way, the movable lifting scaffolding 1 can be strengthened and its safety is improved by connecting the ends of the horizontal movement mechanism 5 and the horizontal movement body 51, which are free ends. In addition, the movable lifting scaffolding 1 allows the pair of left and right horizontal movement mechanisms 5 to pass through each work platform 50 with the connecting part 55, improving the work efficiency of maintenance work.

[0076] (When changing portions) Next, we will explain the case where the movable lifting scaffold 1 is moved horizontally to change its installation position, using Figures 19 and 20. Figure 19 is a perspective view showing the extension of the horizontal movement mechanism 5 when the movable lifting scaffold 1 is moved, and Figure 20 is a perspective view showing the raising of the lifting mechanism 4 when the movable lifting scaffold 1 is moved.

[0077] When moving the movable lifting scaffolding 1 laterally to change its installation position, it is necessary to move it laterally while avoiding the trolley wire TL (see Figures 11 and 12). Therefore, as shown in Figure 19, when moving the movable lifting scaffolding 1 laterally from its installation position during maintenance work in Figure 2 along the direction of travel of the sidewalk WW of the pedestrian bridge Pb to change its installation position, first, as described above, the horizontal movement mechanism 5 is moved electrically or manually using the slide rail 54 to pull the horizontal movement mechanism 5 outward in the direction of the arrow in the figure.

[0078] Subsequently, as shown in Figure 20, the electric motor 40 of the lifting mechanism 4 rotates the pinion gear, engaging it with the rack 21 formed on the mast 2a, and raising the lifting mechanism 4 and the horizontal movement mechanism 5 along the mast 2a (gate-type frame 2). Specifically, the horizontal movement mechanism 5 is raised until the lower surface of the work platform 50, which is the lower end of the horizontal movement mechanism 5, exceeds the lower surface of the pedestrian bridge Pb and reaches above it.

[0079] Then, the movable lifting scaffolding 1 is pushed manually and driven along the sidewalk WW of the pedestrian bridge Pb using the wheels 33 of the lower moving mechanism 3, moving the entire movable lifting scaffolding 1 laterally in the direction of the arrow in the diagram to the predetermined position and changing its installation location.

[0080] Furthermore, when maintenance work is not being performed, such as during daytime train operation, the movable lifting scaffolding 1 can be moved away from the tracks and positioned at the end of the pedestrian bridge Pb. Similar to when the scaffolding is being repositioned, it can be held in a position where the lower surface of the work platform 50, which is the lower end of the horizontal movement mechanism 5, is positioned above the lower surface of the pedestrian bridge Pb, and then evacuated. By holding the movable lifting scaffolding 1 in this position, it becomes unnecessary to completely remove the movable lifting scaffolding 1 from the pedestrian bridge Pb even when trains are running. As a result, it is not necessary to set up temporary scaffolding, perform maintenance work, and remove temporary scaffolding in the limited short time at night when trains are not passing, and almost all of the time when trains are not passing can be dedicated to maintenance work.

[0081] Furthermore, as shown in Figure 10, the mobile lifting scaffolding 1 is based on a gate-type frame 2, which has increased rigidity by connecting a pair of left and right masts 2a, which are twin masts, to a beam 2b. Therefore, even when the mobile lifting scaffolding 1 is installed on the pedestrian bridge Pb, it is possible to secure a space of 3m or more in height that allows people and bicycles to pass through. For this reason, even when the mobile lifting scaffolding 1 is moved away from the trolley wire TL during the daytime, it does not obstruct the passage of bicycles or pedestrians. Thus, it eliminates the need to assemble and dismantle temporary scaffolding for each nighttime maintenance work, as was done in the past.

[0082] According to the mobile lifting scaffolding 1 of this embodiment described above, it can be used for maintenance work on overpasses where sufficient clearance cannot be maintained between the trolley wire and the overpass. Furthermore, it eliminates the need to completely remove the mobile lifting scaffolding 1 during the daytime when trains are passing, and eliminates the need to assemble and disassemble it for each nighttime work session when trains are not passing.

[0083] Furthermore, the movable lifting scaffolding 1 has rail wheels 33a that run on rails 36 installed along both edges of the pedestrian bridge Pb next to the sidewalk WW, and base jacks 34 that lift and separate the rail wheels 33a from the sidewalk WW of the pedestrian bridge Pb. Therefore, the movable lifting scaffolding 1 can be easily moved by hand on the pedestrian bridge Pb and installed between multiple trolley wires TL.

[0084] Furthermore, with the movable lifting scaffolding 1, the slide rail 54 is slidably supported by the rail support member 49 of the lifting section 42 of the lifting mechanism 4, so that the horizontal moving body 51 can slide freely relative to the lifting section 42 manually or electrically. For this reason, the horizontal moving body 51 with a work platform 50 can be set up next to the trolley wire TL during nighttime maintenance work, and during daytime train operation, the horizontal moving body 51 can be raised above the underside of the pedestrian bridge Pb and easily moved out of the way without removing the movable lifting scaffolding 1.

[0085] Furthermore, with the mobile lifting scaffolding 1, the longitudinal ends of a pair of horizontal moving bodies 51 can be connected at a connecting section 55 having a work platform, thus enabling the connection of ends of horizontal moving bodies 51, where one end in the longitudinal direction is a free end, thereby improving structural safety. Moreover, with the mobile lifting scaffolding 1, the work platforms 50 of the pair of horizontal moving bodies 51 are configured to allow passage between them via the connecting section 55, thus improving the efficiency of maintenance work.

[0086] Although the movable lifting scaffolding 1 according to an embodiment of the present invention has been described in detail above, the embodiments described or illustrated above are merely examples of embodiments that have been materialized in carrying out the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these embodiments. In particular, although a pedestrian bridge was used as an example to describe a structure in close proximity to a trolley wire, the invention can also be applied to other structures such as bicycle bridges and automobile bridges. [Explanation of Symbols]

[0087] 1: Mobile lifting scaffolding 2: Gate-type frame 2a: Mast 2a': Extension mast 2b: Beam 20: Rectangular steel pipe 21: Rack 22: Junction Box 23: Joining member 3: Lower movement mechanism 30: Base frame 31:Joint part 32: Connecting bolts 33:Wheel 33a: Rail wheels (wheels) 33b: Caster (wheel) 34: Base jack 35: Jack Box 36: Rail 4: Lifting mechanism 40: Electric motor 41: Drive unit 42: Elevator 43: Upper Stage 44: Handrail 45: Guard fence 46: Control Panel 47: Entrance / Exit Door 48: Elevator ladder 49: Rail support material 5: Horizontal movement mechanism 50: Work platform 51: Horizontal moving object 52: Handrail 53: Baseboard 54: Slide rail 55: Connection part 6: Joining member Pb: Pedestrian overpass (structure) Ph: High railing WW: Sidewalk OL: Streetlight (obstacle) TL: Trolley wire CL: Crane

Claims

1. A mobile, liftable scaffolding for performing maintenance work on an overpass erected above a trolley line, The overpass comprises a pair of left and right rails installed along both edges of the road surface, a pair of left and right lower moving mechanisms that run on the pair of left and right rails, a pair of left and right masts erected on the lower moving mechanisms, a pair of left and right lifting mechanisms that perform an up and down movement along the masts, a beam connecting the pair of left and right lifting mechanisms, and a pair of left and right horizontal moving mechanisms that are suspended and supported by each of the lifting mechanisms of the pair of lifting mechanisms and are capable of moving horizontally below the overpass. The beam is positioned so that even when the lifting mechanism is at its lowest height, it is at a height that allows people to pass over the road surface of the overpass. The pair of left and right horizontal movement mechanisms each comprises a horizontal movement body having a work platform, and a slide rail is attached to the lower part of each horizontal movement body, and the slide rail is slidably supported in the lifting section of the lifting mechanism, and the horizontal movement bodies are configured to be slidably moved manually or electrically, At least the support material that supports the work platform shall be insulated or made of insulating material. A mobile, liftable scaffolding system characterized by the following features.

2. The aforementioned lifting mechanism includes an electric motor that rotates a pinion gear, The mast has a rack that meshes with the pinion gear. The lifting mechanism rotates the pinion gear with the electric motor to move up and down along the mast on which the rack is formed. A mobile lifting scaffold according to claim 1, characterized by the above.

3. The lower moving mechanism includes wheels that travel on the rails and base jacks that lift and separate the wheels from the road surface of the overpass. A movable lifting scaffold according to claim 1, characterized by the above.

4. The lifting mechanism is configured such that, when maintenance work is not being performed, the work platform can be raised above the underside of the overpass. A movable lifting scaffold according to claim 1, characterized by the above.

5. The pair of horizontally moving bodies are configured so that their longitudinal ends can be connected to each other, and so that they can pass between each other's work platforms. A movable lifting scaffold according to claim 1, characterized by the above.

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