Construction method and construction device for suspended scaffolding

Abstract

To provide a construction method and construction devices for a suspended scaffolding.SOLUTION: A construction method of a suspended scaffolding constructs stages suspended with cables on an existing structure and expands the stage by sequentially extending the stage from the preceding side towards the subsequent side. The construction method, for constructing a subsequent stage (S2) after a preceding stage (S1) previously constructed, is constituted in such a way that: a subsequent-side girder member (4) to be arranged in the subsequent stage has the end vicinity part of the subsequent-side girder member (4) connected to a main beam (1a) of the subsequent stage on the extended line of the longitudinal axis line of a preceding-side girder member (4a) that is arranged in the preceding stage; and a butting part (31) on the subsequent-side girder member (4) is butted against a bearing part (32) that is located in the under side of the aforesaid main beam (1a) and is arranged on the preceding-side girder member (4a).SELECTED DRAWING: Figure 18

Description

Technical Field

[0001] The present invention relates to a method for constructing a suspension scaffold and an apparatus for implementing the construction method.

Background Art

[0002] Conventionally, for the construction and renovation of elevated structures such as highways and bridges and other existing structures at high altitudes, a suspension scaffold extending along the existing structure has been constructed.

[0003] The suspension scaffold is constructed by building a stage suspended by a cable such as a chain on the existing structure, and successively adding extensions to the stage while extending it from the leading side to the trailing side.

[0004] At this time, the stage is constructed by forming a grid framework by connecting beam members and laying a floor board on the grid.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Since the suspension scaffold forms a grid framework by connecting beam members in the air, dangerous work is forced. Therefore, in order to ensure safety and enable rapid construction, it is desirable to configure the structure so that a structure with high strength can be constructed with as easy work as possible.

[0007] An object of the present invention is to provide a method for constructing a suspension scaffold and a construction apparatus that can meet such needs.

Means for Solving the Problem

[0008] Therefore, the construction method of the suspension scaffold of the present invention is configured as a means to construct a stage suspended by a cable on an existing structure, and sequentially add and extend the stage from the leading side to the trailing side. The stage is formed by arranging beam members suspended by cables in parallel on the leading side (X1) and the trailing side (X2) to form a main beam (1a) and a secondary beam (1b), and a grid (G) formed by connecting the main beam and the secondary beam at intervals in the parallel direction with girder members, and is composed of a floor board laid on the grid. When constructing a subsequent stage (S2) with respect to the previously constructed leading stage (S1), the trailing side girder member provided on the subsequent stage is on the extension line of the longitudinal axis of the leading side girder member provided on the leading stage, and the vicinity of the tail end of the trailing side girder member is connected to the main beam of the subsequent stage and is located below the main beam. The contact portion provided on the trailing side girder member is configured to contact the support portion provided on the leading side girder member.

[0009] In an embodiment of the present invention, by connecting the vicinity of the tail end to the main beam of the subsequent stage and bringing the contact portion into contact with the support portion, the trailing side girder member is cantilever-supported on the main beam, a floor board is laid on the girder member, and then, by connecting the vicinity of the tip of the girder member to the secondary beam, the grid and the subsequent stage are constructed.

[0010] In another embodiment of the present invention, by connecting the vicinity of the tail end to the main beam of the subsequent stage, bringing the contact portion into contact with the support portion, and connecting the vicinity of the tip of the girder member to the secondary beam to construct a grid, and then laying a floor board on the grid including the girder member, the subsequent stage is constructed.

[0011] And the girder member as an apparatus for implementing the method for constructing the suspension scaffold of the present invention includes an upper frame and a lower frame that are arranged parallel to each other vertically and are connected to each other. A first connecting portion connected to the main beam of the subsequent stage is provided in the vicinity of the tail end of the upper frame, and a second connecting portion connected to the secondary beam of the subsequent stage is provided in the vicinity of the tip end of the upper frame. The contact portion is provided in the vicinity of the tail end of the lower frame, and the support portion is provided in the vicinity of the tip end of the lower frame.

[0012] Preferably, the support portion of the preceding girder member and the contact portion of the subsequent girder member are provided with locking means that lock with each other when the contact portion abuts against the support portion. The locking means is configured to position and hold both girder members on the axis in the longitudinal direction.

[0013] In an embodiment of the present invention, the first connecting portion of the girder member faces the main beam and is provided with a nut and a locking pin with a flange arranged side by side. The main beam is provided with a notch portion formed so that the locking pin can be inserted and locked to the lower surface of the flange, and a fixing hole corresponding to the nut. When the locking pin and the notch portion face the main beam from an oblique direction and the locking pin is inserted into the notch portion, the notch portion is locked to the lower surface of the flange to prevent the girder member from falling, and the girder member is configured to be rotatably supported around the axis of the locking pin. The nut and the fixing hole are configured to overlap each other when the girder member is made orthogonal to the main beam by the rotation, so that a bolt inserted from the fixing hole can be screwed to the nut.

Advantages of the Invention

[0014] According to the present invention, the subsequent digit member 4 on the subsequent side in the subsequent stage is arranged on the extension line of the longitudinal axis of the preceding digit member 4a provided on the preceding stage, and with the first connecting portion 26 in the vicinity of the tail end of the subsequent digit member 4 being connected and fixed to the main beam 1a, it is positioned below the main beam 1a and configured to abut the abutting portion 31 provided on the subsequent digit member 4 against the support portion 32 provided on the preceding digit member 4a, so that it is possible to cantilever-support the digit member 4 on the main beam 1a so as to withstand a downward load. As a result, an operator can board the cantilever-supported digit member 4, and thus there is an effect that work can be performed safely and easily.

Brief Description of the Drawings

[0015]

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Best Mode for Carrying Out the Invention

[0016] The preferred embodiments of the present invention will be described in detail below with reference to the drawings.

[0017] (Overall Configuration) As shown in FIG. 1, the suspended scaffold is constructed by sequentially adding subsequent stages while extending them in the extension direction X from the leading side X1 toward the trailing side X2, with the stage S constructed on the leading side X1 as the leading stage along elevated structures such as highways and bridges or other existing structures (not shown). At this time, if necessary, the subsequent stage may be extended in the width direction Y orthogonal to the extension direction X from the leading stage.

[0018] The stage S initially constructed on the leading side X1 is composed of a reference stage S1 constructed on a device such as the ground or an elevated work platform. After construction, the reference stage S1 is suspended from the existing structure by a cable C such as a chain, and then, using this reference stage S1 as a base for starting work in the air, subsequent stages S2 and S3 are sequentially constructed.

[0019] The stage S is constructed by arranging beam members 1 extending in the width direction Y in parallel on the leading side X1 and the trailing side X2 to form a main beam 1a and a secondary beam 1b, a grid G formed by a framework including the main beam 1a and the secondary beam 1b, and a floor board 2 laid on the grid G.

[0020] Therefore, regarding the relationship between the leading stage and the subsequent stage, when constructing the subsequent stage S2, the secondary beam 1b of the leading stage S1 is used as the main beam 1a of the subsequent stage S2. Accordingly, a secondary beam 1b is formed by arranging one beam member 1 on the trailing side X2, and a grid G for the stage S2 is constructed between the main beam 1a and the secondary beam 1b.

[0021] At this time, the grid G is formed by the main beam 1a and the secondary beam 1b arranged in parallel, side frames 3 connecting both ends of the main beam 1a and the secondary beam 1b, and a plurality of cross members 4 connecting the main beam 1a and the secondary beam 1b at intervals in the parallel direction (width direction Y in the figure).

[0022] (Beam member) The beam member 1 may be constituted by a single member extending in the width direction Y. However, in the case of the illustrated embodiment, it is formed by connecting and arranging a long basic beam 5a and a short extension beam 5b in series in the width direction Y, and in the case of the illustrated embodiment, they are integrally connected by a connecting fitting 12 described later.

[0023] As shown in FIGS. 3 and 4, the basic beam 5a and the extension beam 5b are substantially the same in configuration except for the difference in length, and are formed into a cross-sectional shape by combining steel materials having an L-shaped cross section and fixing and integrating them by welding or the like, and include a vertical upper plate portion 6a and a vertical lower plate portion 6b, and a horizontal front plate portion 7a and a horizontal rear plate portion 7b extending in the front-rear direction of the extension direction X.

[0024] Among the vertical upper plate portion 6a and the vertical lower plate portion 6b, a predetermined number of suspension holes 8 are formed through the vertical upper plate portion 6a at intervals in the longitudinal direction, and a cable C such as a chain is connected to the predetermined suspension holes 8. Further, fixing holes 14 for fixing a connecting fitting 12 described later are formed through the vertical lower plate portion 6b.

[0025] Among the suspension holes 8 provided in the vertical upper plate portion 6a, several selected holes are used as locking holes 8a for locking a fixing fitting 39 for accessories described later (see FIG. 12), and are also used as pivot holes 8b for pivotally supporting a pressing fitting 43 described later (see FIG. 13).

[0026] Among the horizontal front plate portion 7a and the horizontal rear plate portion 7b, a notch portion 33 and a fixing hole 34 corresponding to a first connecting portion 26 of a girder member 4 described later are provided in the horizontal front plate portion 7a (see FIGS. 4 and 11), and an insertion hole 36 corresponding to a second connecting portion 27 of the girder member 4 described later is provided in the horizontal rear plate portion 7b (see FIGS. 3 and 11).

[0027] A front connecting plate 9a fixedly provided so as to close the space between the vertical upper plate portion 6a and the horizontal front plate portion 7a, and a rear connecting plate 9b fixedly provided so as to close the space between the vertical upper plate portion 6a and the horizontal rear plate portion 7b are provided at both ends of each of the basic beam 5a and the extension beam 5b, and bolt insertion holes 10 are formed in the front connecting plate 9a and the rear connecting plate 9b.

[0028] Thus, when the basic beam 5a and the extension beam 5b are arranged in series in the width direction Y, the front connecting plates 9a and the rear connecting plates 9b thereof are overlapped with each other, and the bolt insertion holes 10 communicate with each other. At this time, as shown in the figure, since the nut 11 is fixed to one of the two overlapped connecting plates 9a, 9b by welding or the like, the basic beam 5a and the extension beam 5b are connected by fastening the bolt (not shown) inserted through the insertion hole 10 to the nut 11.

[0029] Furthermore, as shown in FIG. 5, the vertical lower plate portion 6b of the basic beam 5a and the vertical lower plate portion 6b of the extension beam 5b are integrally connected by a connecting fitting 12. The connecting fitting 12 includes groove-shaped side walls 12a, 12b into which the vertical lower plate portion 6b is fitted. With the pin 13 provided at the extension of one side wall 12a inserted and locked into the fixing hole 14 provided in one of the vertical lower plate portions 6b of the basic beam 5a and the extension beam 5b, a bolt 16a is inserted through the insertion hole 15 formed through the side walls 12a, 12b and a nut 16b is fastened to the fixing hole 14 provided in the other vertical lower plate portion 6b.

[0030] (Side Frame) As shown in FIGS. 6 and 7, the side frame 3 is formed of a square pipe member extending in the X direction, and fixing plates 17 fixed to the lower surfaces of both ends are respectively projected from the ends, and insertion holes 18 are provided in the projecting portions.

[0031] Therefore, as shown in the figure, the side frame 3 is arranged between both ends of the main beam 1a and both ends of the secondary beam 1b. The fixing plates 17 are overlapped with the lower surfaces of the horizontal front plate portion 7a of the main beam 1a and the horizontal rear plate portion 7b of the secondary beam 1b, and are fixed by bolts 19a and nuts 19b through the insertion holes 18. For this reason, bolt insertion holes 20 are provided in the horizontal front plate portion 7a and the horizontal rear plate portion 7b.

[0032] In the illustrated embodiment, as shown in FIGS. 1 and 2, the grid G for constructing the stage S is formed by connecting both ends of the basic beam 5a and both ends of the extension beam 5b with four side frames 3 between the main beam 1a and the sub-beam 1b. That is, between the main beam 1a and the sub-beam 1b, a wide grid G1 framed by connecting both ends of the basic beam 5a with the side frames 3 and a narrow grid G2 framed by connecting both ends of the extension beam 5b with the side frames 3 are connected in series, and as a whole, one grid G is formed, and the stage S is formed by laying the floorboard 2.

[0033] Therefore, the floorboard 2 is composed of a long floorboard 2a laid on the wide grid G1 and a short floorboard 2b laid on the narrow grid G2.

[0034] (Stringer member) As shown in FIGS. 8 to 11, the stringer member 4 forms a rigid frame structure by arranging an upper frame 21 and a lower frame 22 formed of round pipe materials in parallel up and down and connecting and integrating them with a bundled material 23, and provides support plates 24 and 25 for connecting both ends of both frames 21 and 22 facing the leading side X1 and the trailing side X2 in the X direction.

[0035] At this time, as shown in the figure, the lower frame 22 is formed with a dimension longer than that of the upper frame 21, and overhanging portions 24a and 25a facing both ends of the upper frame 21 are provided by the support plates 24 and 25 standing up from the lower frame 22.

[0036] Therefore, the upper frame 21 is provided with a first connecting portion 26 at the overhanging portion 24a facing the leading side X1 in the X direction and a second connecting portion 27 at the overhanging portion 25a facing the trailing side X2.

[0037] The first connecting portion 26 is configured by arranging a nut 28 that extends long in the vertical direction and a locking pin 29 with a flange side by side. The nut 28 is fixed by welding or the like to a notch formed in the overhanging portion 24a. The locking pin 29 is fixed by welding or the like to a bracket 24b fixed so as to intersect the overhanging portion 24a. At this time, with respect to the vertical height direction, as indicated by reference numeral (h) in FIG. 8(C), the flange 29a of the locking pin 29 is disposed at a position higher than the upper end of the nut 28. Incidentally, the height difference (h) is equal to or slightly larger than the thickness (t) of the horizontal front plate portion 7a of the beam member 1.

[0038] The second connecting portion 27 is configured by a nut 30 that extends long in the vertical direction. The nut 30 is fixed by welding or the like to a notch formed in the overhanging portion 25a.

[0039] The lower frame 22 forms a contact portion 31 by a flat plate 31a fixed to an end facing the leading side X1 in the X direction, and forms a support portion 32 by a flat plate 32a fixed to an end facing the trailing side X2.

[0040] (Relationship between the first connecting portion and the main beam) As shown in FIG. 9, at a predetermined position where the beam member 1 connects the girder members 4, a notch portion 33 and a fixing hole 34 are arranged side by side in the horizontal front plate portion 7a. The notch portion 33 is formed to have a size that allows the locking pin 29 of the first connecting portion 26 to be inserted and supports the lower surface of the flange 29a. Further, the fixing hole 34 is formed to have the same diameter as or slightly larger than the nut 28 of the first connecting portion 26.

[0041] When connecting the girder member 4 to the beam member 1 constituting the main beam 1a, as shown in FIGS. 9 and 10, with the girder member 4 in an obliquely intersecting posture with respect to the beam member 1, when the locking pin 29 of the first connecting portion 26 is inserted into the notch portion 33 from the obliquely intersecting direction, the flange 29a can be placed on the horizontal front plate portion 7a of the beam member 1. In this state, the notch portion 33 engages with the lower surface of the flange 29a to prevent the girder member 4 from falling, and the girder member 4 is supported so as to be rotatable around the axis of the locking pin 29.

[0042] Subsequently, when the digit member 4 is made orthogonal to the beam member 1 by rotating around the axis of the locking pin 29, as shown in FIG. 11, the nut 28 of the first connecting portion 26 enters the lower surface of the horizontal front plate portion 7a of the beam member 1 and overlaps with the fixing hole 34.

[0043] Therefore, if a headed bolt 35 is inserted from above the fixing hole 34 and screwed onto the nut 28, the digit member 4 is connected and fixed to the beam member 1 (main beam 1a) by the first connecting portion 26.

[0044] In this way, the digit member 4 remains in an obliquely intersecting posture with respect to the main beam 1a, and is supported rotatably while being prevented from falling by the first connecting portion 26 on the tail end side, so that an operator can perform work safely and easily from the preceding stage.

[0045] (Relationship between the second connecting portion and the secondary beam) As shown in FIG. 11, the beam member 1 is provided with an insertion hole 36 in the horizontal rear plate portion 7b at a predetermined position for connecting the digit member 4. At this time, the insertion hole 36 is provided at a position aligned with the fixing hole 34 in the X direction, and is formed to have the same diameter as or slightly larger than the nut 30 of the second connecting portion 27.

[0046] Therefore, when the nut 30 of the second connecting portion 27 of the digit member 4 is made to enter the lower side of the horizontal rear plate portion 7b with respect to the secondary beam 1b, the nut 30 overlaps with the insertion hole 36. Thus, if a headed bolt 37 is inserted from above the insertion hole 36 and screwed onto the nut 30, the digit member 4 is connected and fixed to the beam member 1 (secondary beam 1b) by the second connecting portion 27.

[0047] Incidentally, the nut 30 of the second connecting portion 27, the insertion hole 36, and the headed bolt 37 constitute a lift fixing means 38, which will be described later.

[0048] (Fixing brackets for accessories) Figure 12 shows a fixing fitting 39 for fixing accessories. The fixing fitting 39 has a clamp fitting 41 provided on a fixing base 40, and as shown in FIGS. 1 and 2, it is attached to the beam member 1 facing a predetermined position of the stage S.

[0049] Since the clamp fitting 41 is a well-known fastening fitting used in temporary scaffolds etc., detailed description thereof is omitted.

[0050] The fixing base 40 forms a top plate portion 40a, a side plate portion 40b, and an inclined plate portion 40c that is bent so as to chamfer the corner therebetween by bending a metal plate, and the clamp fitting 41 is fixed to the top plate portion 40a.

[0051] And a bolt 42 is provided on the inclined plate portion 40c so as to be screwed in through a female screw such as a nut and be able to advance and retreat obliquely downward.

[0052] A leg plate 40d is vertically provided on the lower surface of the top plate portion 40a, and when the side plate portion 40b is placed on the horizontal front plate portion 7a of the beam member 1, the leg plate piece 40d is configured to be placed on the horizontal rear plate portion 7b. And a protrusion 40e provided on the inner edge of the leg plate piece 40d is configured to be inserted and locked into the suspension hole 8 provided on the vertical upper plate portion 6a of the beam member 1.

[0053] Therefore, when the bolt 42 is advanced, the fixing fitting 39 can be easily attached to a predetermined position of the beam member 1 by sandwiching the vertical upper plate portion 6a of the beam member 1 between the leg plate 40d and the tip of the bolt 42.

[0054] (Pressing fitting) FIGS. 13 to 15 show a pressing fitting 43 for preventing the floor board 2 laid on each stage S from lifting. The pressing fitting 43 is installed between the main beam 1a and the secondary beam 1b facing a predetermined position of the stage S as shown in FIGS. 1 and 2.

[0055] The pressing fitting 43 includes a rod member 44 that crosses over the floor board 2 and is disposed across between the main beam 1a and the secondary beam 1b, arm portions 45a and 45b vertically provided obliquely downward from both ends of the rod member 44, and tongue pieces 46 projecting oppositely from the pair of arm portions 45a and 45b. And an operating bolt 49 is screwed into the tongue piece 46 so as to be able to advance and retreat from above.

[0056] The arm portions 45a and 45b located at both ends of the rod member 44 are configured to fit and be inserted between the vertical upper plate portions 6a of the main beam 1a and the secondary beam 1b. One arm portion 45a is provided with a fixing pin 47 to be inserted into the pivot hole 8c of the vertical upper plate portion 6a of the main beam 1a, and the other arm portion 45b is provided with a detachable pin 48 to be inserted into the pivot hole 8c of the vertical upper plate portion 6a of the secondary beam 1b.

[0057] Therefore, when fitting the pair of arm portions 45a and 45b between the vertical upper plate portions 6a and 6a of the main beam 1a and the secondary beam 1b, by inserting the fixing pin 47 projecting from one arm portion 45a into one pivot hole 8b, the other arm portion 45b is aligned along the vertical upper plate portion 6a, and in this state, the detachable pin 48 may be inserted into the other pivot hole 8b through the pin hole 48a of the arm portion 45b.

[0058] At this time, as shown in FIG. 14, the tip of the operating bolt 49 abuts on the upper surfaces of the horizontal front plate portion 7a and the horizontal rear plate portion 7b of the main beam 1a and the secondary beam 1b. However, if the operating bolt 49 is retracted, the rod member 44 faces an upper position where it does not interfere with the floor board 2, so that the pressing fitting 43 can be suitably installed.

[0059] And after installation, as shown in FIG. 15, when the operating bolt 49 is advanced, the arm portions 45a and 45b are rotated about the pins 47 and 48, whereby the rod member 44 is aligned along the upper surface of the floor board 2 to prevent the floor board 2 from lifting.

[0060] (Construction method of subsequent stage) As described above, the present invention relates to a method of sequentially constructing a subsequent stage S2 from a preceding stage S1, and preferred embodiments thereof will be described below.

[0061] (Connecting step of the girder members) When constructing the subsequent stage S2, by using the secondary beam 1b of the preceding stage S1 as the main beam 1a of the subsequent stage S2, first, as shown in FIG. 16, a step of connecting the tail end portion of the girder member 4 to the main beam 1a (hereinafter referred to as the "tail end connection step of the girder member") is performed. At this time, the girder member 4 with the tail end portion connected is aligned in the X direction. Then, as shown in FIG. 17, a new secondary beam 1b is installed, and a step of connecting the tip end portion of the girder member 4 to the secondary beam 1b (hereinafter referred to as the "tip end connection step of the girder member") is performed.

[0062] As shown in FIG. 17, the subsequent stage S2 is formed by laying the floor board 2 on the framed grid G by connecting the main beam 1a and the secondary beam 1b with the girder member 4 and connecting both ends with the side frame 3.

[0063] Regarding this point, the connecting step of the side frame 3 may be performed either before or after the tip end connection step of the girder member.

[0064] Also, the laying step of the floor board 2 may be performed either before or after the tip end connection step of the girder member. However, in the embodiments described below, it is performed after the tail end connection step of the girder member and before the tip end connection step of the girder member.

[0065] (Tail end connection step of the girder member) FIGS. 18 and 19 show the tail end connection step of the girder member. For convenience of explanation and understanding, the girder member disposed in the preceding stage S1 is denoted by reference numeral 4a, and the girder member installed in the subsequent stage S2 is denoted by reference numeral 4 (FIGS. 16 and 17 also show the girder member with the same reference numerals).

[0066] The girder member 4 installed in the subsequent stage S2 is connected to the main beam 1a by the first connecting portion 28 at the tail end on the extension line of the longitudinal axis of the preceding girder member 4a provided in the preceding stage S1. At this time, the girder member 4 is rotatably supported by the locking pin 29 with a flange in the notch portion 33 of the main beam 1a, and is fixed by fastening the headed bolt 35 to the nut 28 of the first connecting portion 26 in a state orthogonal to the beam member 1 by rotation. This point is as described above based on FIGS. 9 to 10.

[0067] By the way, as shown in FIGS. 18 and 19, when the subsequent girder member 4 is orthogonal to the main beam 1a and aligned on the extension line of the longitudinal axis of the preceding girder member 4a, it is located below the main beam 1a, and the contact portion 31 of the subsequent girder member 4 abuts against the support portion 32 of the preceding girder member 4a.

[0068] The contact portion 31 and the support portion 32 are constituted by flat plates 31a and 32a fixed to both ends of the lower frame 22, and the plate surfaces are brought into surface contact with each other in a state where the support frames 22 and 22 of the preceding and subsequent girder members 4a and 4 are coaxially aligned.

[0069] Therefore, the subsequent girder member 4 is cantilever-supported by the main beam 1a so as to withstand a predetermined load, so that an operator can perform work while walking on it.

[0070] After connecting a predetermined number of girder members 4 to the main beam 1a, the floor board 2 can be laid, and the operator can continue to perform the tip connection process of the girder member to the secondary beam 1b on the floor board 2.

[0071] (Additional Embodiment) FIG. 20 shows an additional embodiment in which locking means 50 is provided between the contact portion 31 and the support portion 32.

[0072] In the case of the illustration, the locking means 50 is composed of a receiving portion 50a formed by a hole or a recess formed in the support portion 32 and a protrusion 50b protruding from the contact portion 31. When the contact portion 31 is brought into contact with the support portion 32, the protrusion 50b fits into the receiving portion 50a, preventing the contact portion 31 and the support portion 32 from moving relative to each other in the lateral displacement direction.

[0073] (Tip connection process of the girder member) Figs. 21 to 24 show the tip connection process of the girder member. The girder member 4 cantilever-supported on the main girder 1a by the above-described tail end connection process of the girder member is lifted by the lift fixing means 38 to a predetermined position toward the reference member 51 while facing downward below the reference member 51 suspended by a cable C at the second connection portion 27 provided in the vicinity of the tip, and is fixed to the reference member 51 at that position. At this time, the reference member 51 is suspended at a predetermined height position by the cable C.

[0074] In the case of the embodiment shown in Figs. 21 to 24, the reference member 51 is composed of a secondary girder 1b suspended by a cable C. Therefore, the reference member 51 is suspended at the same height position as the main girder 1a. And the lift fixing means 38 is composed of a nut 30 forming the second connection portion 27, an insertion hole 36 provided in the reference member 51 (secondary girder 1b), and a headed bolt 37, as described above.

[0075] As described above, when an operator boards on the girder member 4 cantilever-supported on the main girder 1a, or when the operator boards on the floor board 2 laid on the girder member 4, as shown in Fig. 22, the upper and lower frames 21, 22 extending from the cantilever support portion by the contact portion 31 and the support portion 32 are inclined downward slightly, so a height difference D occurs between the horizontal rear plate portion 7b of the reference member 51 (secondary girder 1b) provided with the insertion hole 36 and the second connection portion 27.

[0076] Therefore, in the tip connection process of the girder member, as shown in Fig. 23, a headed bolt 37 is inserted into the insertion hole 36 from above, and the bolt 37 is driven to rotate while being screwed into the nut 30 (the second connection part 27). As a result, as shown in Fig. 24, the tip of the girder member 4 is pulled up together with the nut 30, and the nut 30 is fastened in a state of abutting against the lower surface of the horizontal rear plate part 7b of the reference member 51 (the secondary beam 1b).

[0077] Thereby, the subsequent stage S2 is flush with the preceding stage S1, and the subsequent stage S2 provided with the horizontal floor board 2 is constructed.

[0078] (Another embodiment of the tip connection process of the girder member) Figs. 25 and 26 show another embodiment of the tip connection process of the girder member. As shown in Fig. 25, the girder member 4 cantilever-supported on the main beam 1a by the above-described tail end connection process of the girder member is suspended by a cable C at a predetermined height position with the second connection part 27 provided in the vicinity of the tip facing downward of the reference member 51, and is pulled up to a predetermined position toward the reference member 51 by the lift fixing means 38 and fixed to the reference member 51 at that position. In the case of this embodiment, the reference member 51 is constituted by a support member 52 for subsequently connecting and fixing the secondary beam 1b.

[0079] Therefore, as shown in Fig. 25(B), after the second connection part 27 of the girder member 4 is connected and fixed to the support member 52 as the reference member 51, the secondary beam 1b is fixed to the support member 52 via the connection fixing means 53. The height position of the reference member 51 is set in advance so that the secondary beam 1b has the same height as the main beam 1a when the secondary beam 1b is connected and fixed to the reference member 51. Thereby, the horizontal extension of the stage can be easily performed.

[0080] In the case of this embodiment, when the secondary beam 1b is further used as the main beam 1a in the subsequent stage S3 and the first connecting portion 26 of the subsequent side girder member 4b is connected and fixed, the distance L between the first connecting portion 26 of the preceding side girder member 4 and the second connecting portion 27 of the subsequent side girder member 4b becomes longer. However, by extending the mutual lower frames 22, 22 so as to be close to each other, the contact portion 31 is configured to be in contact with the support portion 32.

Explanation of Signs

[0081] X Extension direction X1 Preceding side X2 Subsequent side Y Width direction S Stage C Cable G Grid 1 Beam member 1a Main beam 1b Secondary beam 2, 2a, 2b Floor board 3 Side frame 4, 4a, 4b Girder member 5a Basic beam 5b Extension beam 6a Vertical upper plate portion 6b Vertical lower plate portion 7a Horizontal front plate portion 7b Horizontal rear plate portion 8 Suspension hole 8a Locking hole 8b Pivot hole 9a Front connecting plate 9b Rear connecting plate 10 Bolt insertion hole 11 Nut 12 Connecting fitting 12a, 12b Side wall 13 Pin 14 Fixing hole 15 Insertion hole 16a Bolt 16b Nut 17 Fixing plate 18 Insertion hole 19a Bolt 19b Nut 20 Bolt insertion hole 21 Upper frame 22 Lower frame 23 Bundled material 24, 25 Support plates 24a, 25a Overhanging parts 24b Bracket 26 First connecting part 27 Second connecting part 28 Nut (first connecting part) 29 Locking pin (first connecting part) 29a Flange 30 Nut (second connecting part) 31 Contact part 31a Flat plate 32 Support part 32a Flat plate 33 Notch part 34 Fixing hole 35 Bolt with head 36 Insertion hole 37 Bolt with head 38 Lift fixing means 39 Fixing fitting for accessories 40 Fixing table 40a Top plate part 40b Side plate part 40c Inclined plate part 40d Foot plate piece 40e Protrusion 41 Clamping fitting 42 Bolt 43 Pressing fitting 44 Pole member 45a, 45b Arm parts 46 Tongue piece 47 Fixing pin 48 Detachable pin 48a Pin hole 49 Actuating bolt 50 Locking means 50a Receiving part 50b Protrusion 51 Reference member 52 Support member 53 Connecting and fixing means

Claims

1. A method for constructing a suspended scaffold by constructing a stage suspended by a cable on an existing structure and successively adding to the stage while extending it from the front side to the rear side, wherein the stage is composed of a main beam (1a) and a secondary beam (1b) formed by arranging beam members (1) suspended by cables in parallel on the front side (X1) and the rear side (X2), a grid (G) formed by connecting the main beam (1a) and the secondary beam (1b) at intervals in the parallel direction with cross members (4), and a floor board (2) laid on the grid, when constructing a subsequent stage (S2) with respect to a previously constructed front stage (S1), the cross member (4) on the rear side provided on the subsequent stage is connected to the main beam (1a) of the subsequent stage near the tail end portion on the extension line of the longitudinal axis of the cross member (4a) on the front side provided on the front stage, and is configured to abut a contact portion (31) provided on the cross member (4) on the rear side against a support portion (32) provided on the cross member (4a) on the front side, which is located below the main beam (1a). A method for constructing a suspended scaffold characterized by this.

2. By connecting the near-tail-end portion to the main beam (1a) of the subsequent stage and abutting the contact portion (31) against the support portion (32), the cross member (4) on the rear side is cantilever-supported on the main beam (1a), and a floor board (2) is laid on the cross member (4), and then, by connecting the near-tip portion of the cross member (4) to the secondary beam (1b), a grid (G) and a subsequent stage are constructed. The method for constructing a suspended scaffold according to Claim 1, characterized by this.

3. By connecting the near-tail-end portion to the main beam (1a) of the subsequent stage, abutting the contact portion (31) against the support portion (32), and connecting the near-tip portion of the cross member (4) to the secondary beam (1b), a grid (G) is constructed, and then, by laying a floor board (2) on the grid (G) including the cross member (4), a subsequent stage is constructed. The method for constructing a suspended scaffold according to Claim 1, characterized by this.

4. In the method for constructing a suspended scaffold according to Claim 1, the cross member (4) includes an upper frame (21) and a lower frame (22) arranged parallel to each other vertically and connected to each other. A first connecting portion (26) connected to the main beam (1a) of the subsequent stage is provided near the tail end of the upper frame (21), and a second connecting portion (27) connected to the secondary beam (1b) of the subsequent stage is provided near the tip of the upper frame (21). A contact portion (31) is provided near the tail end of the lower frame (22), and a support portion (32) is provided near the tip of the lower frame (22), and a construction device for a suspension scaffold is characterized in that.

5. The support portion (32) of the preceding girder member (4a) and the contact portion (31) of the subsequent girder member (4) are provided with locking means (50) that lock to each other when the contact portion abuts against the support portion. The locking means (50) is configured to position and hold both girder members on the axis in the longitudinal direction, and the construction device for a suspension scaffold according to claim 4 is characterized in that

6. The first connecting portion (26) of the girder member (4) faces the main beam (1a), and a nut (28) and a locking pin (29) with a flange are arranged side by side. The main beam (1a) is formed with a notch portion (33) into which the locking pin (29) can be inserted and can be locked to the lower surface of the flange (29a), and a fixing hole (34) corresponding to the nut (28). When the locking pin (29) and the notch portion (33) face the main beam (1a) from an oblique direction and the locking pin (29) is inserted into the notch portion (33), the notch portion (33) locks to the lower surface of the flange (29a), preventing the girder member (4) from falling, and the girder member (4) is configured to be rotatably supported around the axis of the locking pin (29). The nut (28) and the fixing hole (34) are configured to overlap each other when the girder member (4) is made orthogonal to the main beam (1a) by the rotation, so that a bolt (35) inserted from the fixing hole (34) is screwed onto the nut (28). The construction device for a suspension scaffold according to claim 4 or 5 is characterized in that

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