Safety handrail and construction girder material with safety handrail

Abstract

To provide a safety handrail for safety of high-place work on an installation girder material used in a very long structure where a product is transported by a truck, for example, a highway or railway viaduct.SOLUTION: A safety handrail according to the present invention is installed on the side of an upper end wide base part 4 of a construction girder material 1, a handrail installation member 10a is attached to the lower end of a support post 9a attached downward from the safety handrail 2 so as to be relatively swingable around a horizontal support shaft 35 parallel to the length direction of the handrail, and this handrail installation member 10a is provided with a stopper (stopper bolt 38) that prevents the safety handrail 2 supported by the support post 9a from swinging around the horizontal support shaft 35 from the vertical use posture to the outside of the construction girder material 1, and flexible release fixing means 36 for fixing the support post 9a to the handrail installation member 10a in a vertical use posture.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a safety handrail that is temporarily installed along areas where workers walk at a construction site, and in particular to a safety handrail that can be attached to construction girders used for viaducts on expressways and railways. [Background technology]

[0002] Construction girders used for viaducts of expressways and railways are manufactured from reinforced concrete in a factory, transported to the site by a large truck after completion, and then lowered to the piers of the viaduct or the like by a crane and installed at the site. When such construction girders are manufactured in the factory or installed at the site after transportation, workers walk on the top of the girders to perform various high-altitude work. Therefore, from the viewpoint of ensuring the safety of workers, it is desirable to use a conventionally known temporary safety handrail, such as the safety handrail shown in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-301004 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the safety handrails are high enough to reach the waist of the workers, and if they were left attached to the top of tall beams, they would cause problems during truck transport. Therefore, the safety handrails must be removed when the work is shipped from the factory, and then reattached to the beams after arrival at the site. This requires a great deal of time and effort, including the need to tie down and transport the removed safety handrails during truck transport. [Means for solving the problem]

[0005] The present invention proposes a safety handrail and a girder material for erection with a safety handrail that can solve the above-mentioned problems of the conventional art. The safety handrail according to the first invention, in order to make it easier to understand the relationship with the embodiments described later, the reference symbols used in the description of the embodiments are shown in parentheses. The handrail installation members (10a, 10b) are attached to the lower ends of the support posts (9a, 9b) of the safety handrail (2) so as to be relatively swingable around a horizontal support shaft (35) parallel to the longitudinal direction of the safety handrail. The handrail installation members (10a, 10b) are provided with stoppers (38) that come into contact with the support posts (9a, 9b) and restrict the swinging of the safety handrail (2) only inward or outward in a direction perpendicular to the longitudinal direction of the safety handrail (2), and releasable fixing means (36) that fixes the support posts (9a, 9b) to the handrail installation members (10a, 10b) when the safety handrail (2) is in the upright position for use.

[0006] Moreover, in order to facilitate understanding of the relationship with the embodiments described later, the reference numerals used in the description of the embodiments of the second invention are shown in parentheses in order to make it easier to understand the relationship with the embodiments described later. In the erection girder with safety handrails, safety handrails (2) are detachably arranged along the length of the erection girder (1) on both the left and right sides of the upper surface of the erection girder (1), handrail installation members (10a, 10b) are attached to the lower ends of the support posts (9a, 9b) of the safety handrails (2) on both sides so as to be relatively swingable around horizontal support shafts (35) parallel to the length direction of the safety handrails, and the handrail installation members (10a, 10b) have a pair of mounting members (10a, 10b) protruding downward from the lower ends of the handrail installation members (10a, 10b) and supporting members (10b) for supporting the erection girder (1). The safety handrail (2) is provided with an insert steel pipe (29) that can be inserted and removed freely into the mounting hole (7) opening on the top surface of the installation girder (1), a stopper (38) that abuts against the support pillars (9a, 9b) to suppress only the outward swing of the installation girder (1) when the safety handrail (2) swings around the horizontal support shaft (35) from the upright use position, and a fixing means (36) that can be freely released and that fixes the support pillars (9a, 9b) to the handrail installation members (10a, 10b) when the safety handrail (2) is in the upright use position. When the safety handrail (2) is no longer needed, the entire safety handrail (2) including the handrail installation members (10a, 10b) can be removed by pulling them out of the mounting hole (7) of the installation girder (1). Effect of the Invention

[0007] According to the configuration of the safety handrail of the first invention, the handrail installation member attached to the lower end of the support pole can be used to install the safety handrail wherever necessary, such as the side of the worker's work area, and the function of this safety handrail can be utilized. Naturally, in this usage state, the support pole is fixed to the handrail installation member by the fixing means in the upright usage position, and the safety handrail is held in the usage position where it stands up vertically. When the safety handrail becomes unnecessary, the safety handrail can be released from the fixed state by swinging it around the horizontal support shaft to the side opposite to the side where the swinging is suppressed by the stopper, and the safety handrail can be rotated from the upright usage position to the lying position. Switching the safety handrail to the collapsed position can be done, for example, when the upright safety handrail gets in the way of work inside the safety handrail, by collapsing the safety handrail to the outside of the work area, and when the safety handrail is arranged on both sides of a temporary bridge body that is detachably erected between two structures, for example, when the temporary bridge body is removed and moved to another location, the safety handrail can be collapsed as if folded onto the temporary bridge body, allowing the temporary bridge body to be safely moved together with the safety handrail. In either case, not only is workability improved significantly compared to the conventional handling method of temporarily removing the safety handrail when it is no longer needed and then installing it when it is needed again, but the effect is enormous, as it eliminates the need to store and transport the temporarily removed safety handrail.

[0008] According to the construction of the erection girder with safety handrails according to the second invention, the only additional processing required for the erection girder is to provide mounting holes for supporting the safety handrails, and as long as the mounting holes are blocked during the concrete finishing of the upper surface of the erection girder, no effect remains. When the erection girder is manufactured in the factory, the safety handrails are attached along both the left and right sides of the upper surface of the erection girder, so that the workers standing on the upper side of the erection girder can safely carry out high-altitude work thanks to the presence of the safety handrails on both sides. When the erection girder after the work in the factory is transported by truck to the installation site, the safety handrails attached to both the left and right sides of the upper surface of the erection girder can be folded down to the upper side of the erection girder, while the handrail installation members supported by the steel pipes in the mounting holes of the erection girder are left as they are, and the safety handrails including the support posts above them can be folded down. As a result, the height of the erection girder is increased only by the height of the folded safety handrail, and the safe running of the truck is not hindered, so that the erection girder equipped with the safety handrail can be transported by truck as safely as before. Then, the erection girder transported to the site can have the folded safety handrail raised on the erection girder and fixed by the fixing means, so that the worker standing on the upper side of the erection girder can safely carry out high-altitude work thanks to the presence of the safety handrails on both sides. Once the installation of the erection girder at the site is completed, the handrail installation member on the safety handrail side can be pulled out from the mounting hole of the erection girder, and the safety handrail can be removed from the erection girder.

[0009] As described above, the construction of the erection girder with safety handrail according to the second invention eliminates the need for the work of attaching and detaching the safety handrail to the erection girder before and after truck transport from the factory to the installation site, and the work of transporting the removed safety handrail together with the erection girder, as in the past. In addition, in both the first and second inventions, not only is there a fixing means for fixing the safety handrail in the upright position, but there is also a stopper that limits the direction in which the safety handrail, when released from the fixing means, can be collapsed to either the inside or outside of the safety handrail. This stopper can prevent the safety handrail from rotating in a direction that poses a serious risk to the worker, such as a fall accident, or from collapsing into the work space and interfering with the worker's safe work, even if the fixing means is unexpectedly loosened or released.

[0010] When implementing the first and second aspects of the present invention, specifically, the handrail installation member (10a, 10b) is composed of a U-shaped material (28) in which both side plates (27a, 27b) sandwiching the support pillars (9a, 9b) are integrated with a bottom plate (27c), the horizontal support shaft (35) supporting the support pillars (9a, 9b) is installed between both side plates of the U-shaped material (28), and the fixing means is composed of a pin (36a) that penetrates both side plates (27a, 27b) of the U-shaped material and the support pillars (9a, 9b) in a position vertically away from the horizontal support shaft so that it can be inserted and removed. With this configuration, the handrail installation member can be constructed simply and inexpensively. The fixing means can be various conventionally known means such as bolts and nuts, or a headed pin with a stopper that hangs down by gravity supported at the tip.

[0011] The stopper (38) can be configured by a stopper bolt (38) that is attached to a plate material (34) that connects the vertical sides of one of the side plates (27a, 27b) of the U-shaped material (28) at a height that is spaced apart in the vertical direction from the horizontal support shaft (35) and has its tip abutting the support pillar (9a, 9b). With this configuration, even if the fixing means is a simple configuration using a pin that is inserted into a mounting hole provided in the support pillar, the safety handrail can be held in the upright position without rattling by tightening the bolt as a stopper. Also, the bolt helps to align the center of the fixing means with the center of the fixing means insertion hole of the support pillar by abutting and fastening the support pillar against the bolt, making the fixing means easier to use.

[0012] In the erection girder with safety handrail of the second invention, a cylindrical mounting hole with an inner diameter slightly larger than the outer diameter of the plug-in steel pipe fixed and protruding from the lower end of each handrail installation member is formed so as to open on the upper surface of the erection girder, but it is difficult to make this plug-in steel pipe completely fit the mounting hole, and it is unavoidable that the plug-in steel pipe will wobble slightly in the insertion hole. Since the safety handrail temporarily installed on the long erection girder is arranged with its length direction parallel to the length direction of the erection girder, the wobble of the safety handrail (plug-in steel pipe) in the erection girder length direction is practically almost no problem, but the wobble of the safety handrail in the width direction of the erection girder is a problem that workers who have the opportunity to touch or hold this safety handrail with their hands want to eliminate. Therefore, when implementing the second invention of the handrail-equipped erection girder, the insert steel pipe (29) attached to the handrail installation member (10a, 10b) is a circular steel pipe that is pressurized from both sides in the diameter direction to deform the cross section into an ellipse with a major diameter that is almost the same as the inner diameter of the installation hole and a minor diameter that is shorter than the inner diameter of the installation hole, and this steel pipe (29) is fixed and protruded to the lower end of the handrail installation member (10a, 10b) with its major diameter direction (LR) perpendicular to the length direction of the safety handrail (2) and along the width direction of the erection girder (1). By adopting this configuration, the rattle of the safety handrail in the width direction of the erection girder is eliminated or greatly suppressed, and the adverse effect of the rattle on the worker can be greatly improved. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1A is a schematic perspective view showing an embodiment of the second invention, and FIG. 1B is an enlarged front view of the main part thereof. [Diagram 2] FIG. 2 is an exploded front view of the safety handrail main body. [Diagram 3] FIG. 3 is a front view showing the handrail installation member attached to the support post of the safety handrail main body. [Figure 4] FIG. 4 is an enlarged vertical sectional front view of the main parts, showing the support posts of the safety handrail main body and the handrail installation members in a separated state. [Diagram 5] FIG. 5 is an enlarged vertical sectional front view of a main part of the safety handrail main body. [Figure 6] FIG. 6 is an enlarged cross-sectional plan view showing the pivot points between the support posts of the safety handrail main body and the handrail installation members. [Figure 7] FIG. 7 is an enlarged cross-sectional plan view showing a fixing means between a support post of the safety handrail main body and a handrail installation member. [Figure 8] FIG. 8 is a plan view showing a steel insert pipe attached to the lower end of the handrail installation component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of the second invention employing a safety handrail according to the first invention will be described below with reference to the attached drawings. In Fig. 1A, 1 is a reinforced concrete construction girder for constructing viaducts for roads and railways, and a safety handrail 2 of the present invention is disposed on both the left and right sides along the length of its upper surface. Since this safety handrail 2 is short compared to the overall length of the construction girder 1, multiple safety handrails 2 are disposed in series along the length of the construction girder 1 as shown in the figure. The construction girder 1 is manufactured in a factory and then transported by truck to the site where the viaduct is to be constructed, and is composed of a vertical plate-like portion 3 in the center, a wide upper base portion 4 integrally formed from the upper end of the central vertical plate-like portion 3 so as to protrude significantly to both the left and right sides, and a lower base portion 5 integrally formed from the lower end of the vertical plate-like portion 3 so as to protrude to both the left and right sides. As shown in FIG. 1B, a reinforcing bar 6 protrudes from the upper side of the upper base 4 of the construction girder 1. The reinforcing bar 6 penetrates into the deck slab that is integrally formed on the upper base 4 at the installation site of the construction girder 1, and vertical cylindrical safety handrail mounting holes 7 are formed near both the left and right sides of the upper base 4 to support the safety handrail 2 in a fixed position.

[0015] As shown in Figures 1B to 3, the safety handrail 2 is composed of a horizontally long safety handrail main body 8, two support posts 9a, 9b hanging straight down from two points along the length of the lower side of the safety handrail main body 8, and handrail installation members 10a, 10b attached to the lower ends of each support post 9a, 9b. The horizontally long safety handrail body 8 is divided into three parts: U-shaped members 11, 12 at both ends and an E-shaped member 13 in the center. The U-shaped members 11, 12 at both ends are steel pipes of the same diameter bent into a symmetrical U-shape, and the E-shaped member 13 in the center is made by connecting two small-diameter horizontal steel pipes 13a, 13b at the top and bottom, whose both ends are inserted into the two upper and lower horizontal steel pipe sections 11a, 11b and 12a, 12b of the U-shaped members 11, 12 at both ends, with a vertical steel pipe 13c at their center. Support members 14, 15 are attached to the U-shaped members 11, 12 at both ends, respectively. Both support members 14, 15 have the same structure and are composed of horizontal steel pipes 14a, 14b and 15a, 15b which are fitted around the upper and lower horizontal steel pipe sections 11a, 11b and 12a, 12b of each U-shaped member 11, 12 so as to be freely slidable in the length direction, and vertical steel pipes 14c, 15c which connect and integrate the central positions of the horizontal steel pipes 14a, 14b and 15a, 15b, and the upper ends of the support pillars 9a, 9b are fixed to the central positions of the lower horizontal steel pipes 14b, 15b of both support members 14, 15. Reinforcing members 14d, 15d are fixed obliquely between the support pillars 9a, 9b and the lower horizontal steel pipes 14b, 15b.

[0016] The upper and lower two tiers of small-diameter horizontal steel pipes 13a, 13b of the central E-shaped member 13 have their ends inserted into the upper and lower two tiers of horizontal steel pipe sections 11a, 11b and 12a, 12b of the C-shaped members 11, 12 at both ends, and wing bolts 16, 17 are provided to secure this lower small-diameter horizontal steel pipe 13b to the tips of the lower horizontal steel pipe sections 11b, 12b fitted around it. The details will be explained with reference to Figure 5. Rings 18, 19 are fitted onto the tips of the lower horizontal steel pipes 11b, 12b of the U-shaped members 11, 12, which pass through the lower horizontal steel pipes 14b, 15b of the support members 14, 15. The wing bolts 16, 17 are screwed into radial through-holes 20 provided in these rings 18, 19, and the tips of the wing bolts 16, 17 are pressed against the surface of the small-diameter horizontal steel pipe 13b via wing-bolt positioning through-holes 21 provided so as to pass radially through the horizontal steel pipe portions 11b, 12b. Therefore, if the wing bolts 16, 17 are loosened to the extent that their tips do not come out of the wing-bolt positioning through-holes 21, the fixation between the horizontal steel pipe sections 11b, 12b and the small-diameter horizontal steel pipe 13b is released while the wing bolts 16, 17 are held at the tips of the horizontal steel pipe sections 11b, 12b via the rings 18, 19, and the U-shaped members 11, 12 at both ends can be freely moved in and out of the central L-shaped member 13 to adjust the distance between the U-shaped members 11, 12 at both ends. After adjustment, the wing bolts 16, 17 can simply be tightened.

[0017] On the other hand, the two support members 14, 15 are provided with wing bolts 22, 23 for fixing the two support members 14, 15 to the U-shaped members 11, 12 at both ends. As shown in Fig. 5, the wing bolts 22, 23 screw through nuts 24, 25 fixed to the outside of the horizontal steel pipes 14b, 15b on the lower side of the support members 14, 15, and also pass through radial through holes 26 provided in the horizontal steel pipes 14b, 15b, and are pressed against the circumferential surfaces of the horizontal steel pipe sections 11b, 12b that penetrate the inside of the horizontal steel pipes 14b, 15b. Therefore, by loosening / fastening the wing bolts 22, 23, the position of the support members 14, 15 can be adjusted in the length direction of the horizontal steel pipe sections 11b, 12b relative to the U-shaped members 11, 12 at both ends, and fixed in the adjusted position. The wing bolts 16, 17 can also be screwed through nuts fixed to the outside of the rings 18, 19, and a through hole communicating with the wing-bolt positioning through hole 21 can be provided instead of the screw through hole 20. If the lower horizontal steel pipes 14b, 15b of the support members 14, 15 have a required thickness, the wing bolts 22, 23 can also be screwed through radial screw through holes provided in the horizontal steel pipes 14b, 15b instead of the nuts 24, 25.

[0018] The handrail installation members 10a, 10b attached to the lower ends of the support posts 9a, 9b have the same structure, and as shown in Figures 3, 4, 6, and 7, are made up of a U-shaped material 28 in which both side plates 27a, 27b that sandwich the support posts 9a, 9b from both sides in the longitudinal direction of the safety handrail 2 are integrated with a bottom plate 27c, and the upper end of an insert steel pipe 29 is fixed to the bottom plate 27c of this U-shaped material 28. When the handrail installation members 10a, 10b are attached to the lower ends of the support posts 9a, 9b as described below, this insert steel pipe 29 is concentric with the support posts 9a, 9b. The lower ends of the support columns 9a, 9b are provided with two tiers of mounting holes 30, 31 that penetrate in the diameter direction, and the two side plates 27a, 27b of the U-shaped material 28 are provided with two tiers of mounting holes 32, 33 that can be positioned concentrically with the mounting holes 30, 31. Furthermore, a plate material 34 is fixed between the two side plates 27a, 27b of the U-shaped material 28 so as to close the opening on one side. This plate material 34 is located inside the safety handrail 2, that is, on the inside adjacent to the working space on the upper end wide base part 4 of the erection girder material 1 sandwiched between the safety handrails 2 on both sides in FIG. 1B, and its upper end is located at the midpoint between the two tiers of mounting holes 32, 33 provided on the two side plates 27a, 27b of the U-shaped material 28.

[0019] The support posts 9a, 9b inserted between the both side plates 27a, 27b of the U-shaped material 28 in the handrail installation members 10a, 10b are connected and integrated with the handrail installation members 10a, 10b by a horizontal support shaft 35 inserted into the upper mounting holes 30, 32 that are concentrically aligned with each other, and a fixing means 36 inserted into the lower mounting holes 31, 33. The horizontal support shaft 35 is composed of a bolt 35a and a nut 35b, and the shaft part of the bolt 35a which becomes the horizontal support shaft 35 by the head of the bolt 35a and the nut 35b is fixed to the both side plates 27a, 27b of the U-shaped material 28, and the support posts 9a, 9b (safety handrail 2) can swing freely left and right and laterally around this horizontal support shaft 35, which is perpendicular to the longitudinal direction of the safety handrail 2. The fixing means 36 is composed of a headed pin 36a which can be inserted and removed from the lower mounting holes 31, 33, and a stopper 36c which is pivotally supported by a support shaft 36b at the tip of the headed pin 36a so that it can swing freely, and with the stopper 36c switched to the extended position of the headed pin 36a, it can be inserted and removed from the lower mounting holes 31, 33, but after insertion, the stopper 36c which protrudes on the opposite side hangs down straight down due to gravity, preventing the inserted headed pin 36a from accidentally coming out of the mounting holes 31, 33. The head of the horizontal support shaft 35 (bolt 35a) and the head (bent end) of the headed pin 36a of the fixing means 36 are connected by a flexible connector 37 such as a chain or rope.

[0020] A commonly known fixing means 36 has been exemplified, but when inserted into the mounting holes 31, 33 it will not accidentally fall out and can hold the safety handrail 2 in an upright position relative to the handrail installation members 10a, 10b, but if you want to swing the safety handrail 2 around the horizontal support shaft 35 relative to the handrail installation members 10a, 10b, any structure can be used as long as it can be removed from the mounting holes 31, 33. For example, it may be made of a bolt and nut.

[0021] In Fig. 1B, the safety handrail 2 erected near both the left and right sides of the upper wide base 4 of the erection girder 1 is configured to be able to fall only toward the center of the upper wide base 4 from the upright position shown in the figure. To achieve this, as shown in Figs. 4 and 7, a stopper bolt 38 is attached to the upper end of the plate 34 so as to be located at the middle height between the upper and lower mounting holes 32, 33 provided on both side plates 27a, 27b of the U-shaped material 28, and the tip of this stopper bolt 38 abuts against the support pillars 9a, 9b, preventing the safety handrail 2 (support pillars 9a, 9b) from swinging outward from the upright position shown in Fig. 1B. In the illustrated example, the stopper bolt 38 is screwed through a nut 38a fixed to the inside surface of the plate 34.

[0022] The safety handrail 2 constructed as above can be adjusted in its overall length to suit the location of use. By loosening the wing bolts 16, 17 that connect and fix the U-shaped members 11, 12 at both ends to the central E-shaped member 13, the overall length of the safety handrail 2 can be adjusted by moving the U-shaped members 11, 12 at both ends closer to or farther from the small-diameter horizontal steel pipes 13a, 13b of the central E-shaped member 13. After this adjustment, the wing bolts 16, 17 can be tightened to fix the U-shaped members 11, 12 at both ends again to the central E-shaped member 13. At this time, it is desirable to adjust the overall overall length so that the vertical steel pipe parts 11c, 12c of the U-shaped members 11, 12 at both ends are positioned symmetrically with respect to the vertical steel pipe 13c of the central E-shaped member 13. Also, it is desirable to adjust the positions of the support members 14, 15 provided between the U-shaped members 11, 12 at both ends and the central E-shaped member 13 so that they are positioned symmetrically with respect to the vertical steel pipe 13c of the central E-shaped member 13. The position adjustment of the support members 14, 15 can be performed by loosening the wing bolts 22, 23 to release the fixing of the upper and lower two horizontal steel pipes 14a-15b of the support members 14, 15 to the upper and lower two horizontal steel pipes 11a-12b of the U-shaped members 11, 12 at both ends, then sliding the support members 14, 15 along the upper and lower two horizontal steel pipes 11a-12b of the U-shaped members 11, 12 at both ends to adjust the position, and finally tightening the wing bolts 22, 23 to fix the support members 14, 15 to the U-shaped members 11, 12 at both ends in the adjusted position.

[0023] When the safety handrail 2 is erected on both the left and right sides of the upper wide base 4 of the construction girder 1, the support posts 9a, 9b hanging down from two points in the length direction of the safety handrail main body 8 are erected on both the left and right sides along the length direction of the upper wide base 4 of the construction girder 1 via the handrail installation members 10a, 10b. Specifically, the insertion steel pipes 29 at the lower ends of the handrail installation members 10a, 10b are inserted and installed into the safety handrail mounting holes 7 provided in advance near both the left and right sides along the length direction of the upper wide base 4 of the construction girder 1. At this time, the plate members 34 of the handrail installation members 10a, 10b are oriented so that they are located at the center (inside) of the upper wide base 4 of the construction girder 1 in the width direction. Then, with the bolts 35a of the horizontal support shafts 35 of each of these handrail installation members 10a, 10b and the main bodies 36a of the fixing means 36 removed, the two support posts 9a, 9b of the safety handrail 2 are inserted between the side plates 27a, 27b of the U-shaped material 28 of the two corresponding handrail installation members 10a, 10b. Then, with the upper mounting holes 30 of the support posts 9a, 9b aligned with the upper mounting holes 32 of the U-shaped material 28, the bolts 35a of the horizontal support shaft 35 are inserted into these mounting holes 30, 32, and a nut 35b is screwed onto the free end of the bolt 35a protruding on the opposite side. Next, with the lower mounting holes 31 of the support posts 9a, 9b of the safety handrail 2 aligned with the lower mounting holes 33 of the U-shaped material 28, the headed pin 36a of the fixing means 36 with the anti-slip device 36c in an extended position of the headed pin 36a is inserted into the mounting holes 31, 33, and the anti-slip device 36c protruding on the opposite side is allowed to hang down by gravity.

[0024] By performing the above operations, the safety handrail 2 can be erected on both the left and right sides along the length of the upper wide base portion 4 of the erection girder 1 via the handrail installation members 10a, 10b. Finally, the stopper bolts 38 on each handrail installation member 10a, 10b are tightened so that their tips are pressed against each support pillar 9a, 9b of the safety handrail 2, eliminating any play between the horizontal support shaft 35 (bolt 35a) located above the stopper bolt 38 and each mounting hole 30, 32, and between the headed pin 36a of the fixing means 36 located below the stopper bolt 38 and each mounting hole 31, 33. When work on the upper wide base 4 of the construction girder 1 in the factory is completed and the construction girder 1 is transported by truck to the installation site, the headed pins 36a of the fixing means 36 that hold each safety handrail 2 in an upright position are removed from each handrail installation member 10a, 10b, and the safety handrail 2 together with the supporting posts 9a, 9b are folded down around the horizontal support shaft 35 (bolt 35a) on the upper side of the upper wide base 4 of the construction girder 1, as shown by imaginary lines in Figure 1B. At this time, even if one tries to accidentally rotate the safety handrail 2 outward from the upper wide base 4 of the construction girder 1, it is impossible because the lower ends of the supporting posts 9a, 9b are received by the tips of the stopper bolts 38.

[0025] As described above, by loading the installation girder 1 onto a transport truck with the safety handrail 2 folded onto the upper wide base 4 of the installation girder 1, the loading height of the truck increases only by the height of the folded safety handrail, allowing the installation girder 1 with the integrated safety handrail 2 to be transported by truck relatively safely. The installation girder 1 transported to the installation site can be unloaded from the truck together with the folded safety handrail 2, and transported to the installation site as before and installed. When performing various tasks on the upper wide base 4 of the installed installation girder 1, the folded safety handrail 2 can be returned to its original upright position.

[0026] That is, with the headed pin 36a of the fixing means 36 provided on the handrail installation members 10a, 10b pulled out from the U-shaped member 28, the safety handrail 2 is rotated together with the support posts 9a, 9b in the direction of standing up around the bolt 35a of the horizontal support shaft 35, and the lower ends of the support posts 9a, 9b are abutted against the tips of the stopper bolts 38 provided on the handrail installation members 10a, 10b. At this time, the safety handrail 2 is in an upright use position regulated by the tip position of the stopper bolts 38, and the lower mounting holes 31 of the support posts 9a, 9b and the lower mounting hole 33 of the U-shaped member 28 are approximately concentric, so in this state the headed pin 36a of the fixing means 36 is inserted through both mounting holes 31, 33 with the tip stopper 36c held in the extended position of the headed pin 36a. At this time, if it is difficult to smoothly insert the stopper 36c and the headed pin 36a into the mounting holes 31, 33 due to misalignment between the mounting holes 31, 33, the stopper bolt 38 can be unscrewed to increase the swing range of the support columns 9a, 9b, and the mounting holes 31, 33 can be artificially corrected to a completely concentric state before the stopper 36c and the headed pin 36a are inserted into the mounting holes 31, 33. Once the stopper 36c protrudes outward from the mounting hole 33 of the U-shaped material 28, the stopper 36c can be lowered downward to switch to a state in which the headed pin 36a is prevented from falling out. Finally, if necessary, screw in the stopper bolt 38 to eliminate any wobble in the support pillars 9a, 9b of the safety handrail 2, and work at height on the upper wide base 4 of the installation girder 1 can be carried out in a safe environment with the safety handrails 2 erected on both sides. Once work on the upper wide base 4 of the installation girder 1 is complete, the unnecessary safety handrail 2 and the handrail installation members 10a, 10b can be removed in the reverse order of the installation work.

[0027] Even when the overall length of the safety handrail 2 is extended to its maximum, it is not realistic to realize a safety handrail 2 with an overall length that matches the overall length of the long erection girder 1. Therefore, it is more realistic to arrange multiple safety handrails 2 in series. In this case, it is preferable to connect multiple safety handrails 2 in series together as an integrated unit in order to increase safety. For example, as shown in Figure 3, the U-shaped members 11, 12 at both ends of adjacent safety handrails 2 in series can be connected to each other with a safety handrail connector 39 that can be freely fastened and detached.

[0028] Furthermore, when a prefabricated steel pipe is used for the insert steel pipe 29 attached to the lower end of each handrail installation member 10a, 10b, the safety handrail mounting hole 7 provided in advance in the upper wide base 4 of the erection girder 1 is formed as a cylindrical hole with an inner diameter slightly larger than the outer diameter of the prefabricated steel pipe, or a steel pipe with an inner diameter that can be fitted onto the exterior of the prefabricated steel pipe is embedded in the upper wide base 4, but rattle will inevitably occur between the safety handrail mounting hole 7 and the inserted steel pipe 29 inserted into it. Therefore, the rattle of the inserted steel pipe 29 inserted into the safety handrail mounting hole 7 is expanded and transmitted to the safety handrail located above, causing rattle of the safety handrail that cannot be ignored. In order to alleviate this problem as much as possible, in the present invention, as shown in Figure 8, an inserted steel pipe 29 to be attached to the handrail installation members 10a, 10b is prepared by applying pressure to a circular steel pipe from both sides in the diameter direction to deform it into an ellipse with a minor axis and a major axis in cross section, and this inserted steel pipe 29 is fixed to the bottom surface of the bottom plate 27c of the U-shaped member 28 with its major axis direction LR oriented perpendicular to the longitudinal direction of the safety handrail 2 (the width direction of the erection girder member 1).

[0029] With this configuration, there is no or very little gap between both circumferential surfaces of the wider long diameter direction LR of the inserted steel pipe 29 and the inner circumferential surface of the safety handrail mounting hole 7, and there is no or very little wobble of the support posts 9a, 9b, which are supported at the upper position of this inserted steel pipe 29, and by extension the safety handrail 2, in the direction perpendicular to the longitudinal direction of the safety handrail 2 (the width direction of the erection girder material 1). Conversely, with regard to the narrower short diameter direction SR of the inserted steel pipe 29, the gap with the inner circumferential surface of the safety handrail mounting hole 7 increases, and wobble in the longitudinal direction of the safety handrail 2 increases, but due to the structure of the safety handrail, although there is greater swaying in the width direction perpendicular to the longitudinal direction, there is almost no swaying in the longitudinal direction. For these reasons, by configuring the insertion steel pipe 29 as described above, it may become somewhat more difficult to insert it into the safety handrail mounting hole 7, but the safety handrail is less likely to swing towards the worker positioned inside, thereby improving safety and comfort.

[0030] In the above embodiment, when the safety handrail 2 swings around the horizontal support shaft 35 from the upright use position, a stopper bolt 38 attached to the plate material 34 is provided as a stopper that abuts against the support pillars 9a, 9b to prevent only the outward swing of the erection girder material 1. However, if the configuration of the fixing means 36 can sufficiently prevent the safety handrail 2 (support pillars 9a, 9b) from wobbling, the stopper bolt 38 can be eliminated and the plate material 34 can be used as a stopper to prevent the outward swing of the support pillars 9a, 9b.

[0031] In the above embodiment of the present invention, the safety handrail according to the first invention is described as being used as a safety handrail for use in the erection girder material with safety handrail according to the second invention. However, the safety handrail according to the first invention is not only effective for implementing the erection girder material with safety handrail according to the second invention, but can also be used in various other situations. For example, it can be used as a safety handrail temporarily installed on both sides of a passage structure temporarily installed between two construction structures at a construction site. In this case, the passage structure with the safety handrail that is no longer needed can be removed with the safety handrail folded toward the passage, and transported and installed in a different location. In addition, it can be used as a safety handrail erected around a certain work area on a slab of a construction structure, rather than as a temporary passage structure. In this case, if the safety handrail gets in the way of work within the certain work area, the safety handrail can be collapsed and evacuated outside the certain work area, rather than being removed. [Industrial Applicability]

[0032] The safety handrail of the present invention can be used as a temporary safety handrail along areas where workers walk at a construction site, and in particular as a construction girder material used for highway and railway viaducts, by attaching it to long structures that are manufactured in a factory and transported by truck to the installation site. [Explanation of symbols]

[0033] 1 Girder material for erection 2. Safety handrails 3 Vertical plate 4 Upper end wide pedestal part 5 Lower end base 6. Steel Bars 7 Safety handrail mounting hole 8. Safety handrail body 9a,9b Support column 10a, 10b Handrail installation members 11, 12 U-shaped members at both ends 11a, 11b, 12a, 12b Horizontal steel pipe section in two levels 11c, 12c Vertical steel pipe section 13. Central E-shaped member 13a,13b Small diameter horizontal steel pipe 13c Vertical steel pipe 14,15 Support member 14a,14b,15a,15b horizontal steel pipe 14c,15c Vertical steel pipe 14d, 15d Reinforcing members 16,17,22,23 Wing bolt 18,19 Ring 20 through screw holes 21 Wing bolt positioning through hole 24,25,35b,38a Nut 26 Through hole 27a, 27b Side plates 27c bottom plate 28 U-shaped member 29 Inserted steel pipe 30~33 Mounting holes 34 Board material 35 Horizontal support shaft 35a Bolt 36 Fixing means 36a Headed pin 36b Support shaft 36c Stopper 37 Flexible Connector 38 Stopper bolt 39 Safety handrail connector

Claims

1. A safety handrail in which a handrail installation member is attached to the lower end of the supporting post of the safety handrail so as to be able to swing freely relative to the horizontal support axis parallel to the longitudinal direction of the safety handrail, and this handrail installation member is provided with a stopper that abuts against the support post and prevents the safety handrail from swinging only to one side, either the inside or the outside, perpendicular to the longitudinal direction of the safety handrail, and a fixing means that can be freely released and fixes the support post to the handrail installation member when the safety handrail is in the upright position for use.

2. The safety handrail described in claim 1, wherein the handrail installation member is composed of a U-shaped material with both side panels that sandwich the support post integrated with a bottom panel, the horizontal support shaft that supports the support post is installed between the both side panels of the U-shaped material, and the fixing means is composed of a pin-shaped fixing device that can be freely inserted and removed and that penetrates both side panels of the U-shaped material and the support post at a position vertically spaced from the horizontal support shaft.

3. The safety handrail described in claim 1, wherein the stopper is attached at a height vertically spaced from the horizontal support axis of a plate material connecting one of the vertical side edges of both side panels of the U-shaped material, and is constituted by a bolt whose tip abuts against the support pillar.

4. In an erection girder with safety handrails, which are detachably arranged along the length of the erection girder on both the left and right sides of the upper surface of the erection girder, handrail installation members are attached to the lower ends of the support posts of the safety handrails on both sides so as to be relatively swingable around horizontal support shafts parallel to the length of the handrails, and the handrail installation members include an insertion steel pipe that protrudes downward from the lower end of the handrail installation member and can be inserted and removed from an installation hole that opens on the upper surface of the erection girder, and a steel pipe that is inserted into and removed from the installation hole. An erection girder with a safety handrail is provided with a stopper that abuts against the support post to prevent only the outward swing of the erection girder when it swings around the horizontal support axis from the upright use position, and a releasable fixing means that fixes the support post to a handrail installation member when the safety handrail is in the upright use position, and is configured so that when the safety handrail is no longer needed, the entire safety handrail including the handrail installation member can be removed by pulling it out from the mounting hole of the erection girder.

5. The handrail installation member is composed of a U-shaped material with both side panels that sandwich the support post integrated with a bottom panel, the horizontal support shaft that supports the support post is installed between the both side panels of the U-shaped material, and the fixing means is composed of a pin-shaped fixing device that can be freely inserted and removed between the both side panels of the U-shaped material and the support post at a position vertically spaced from the horizontal support shaft.

6. The stopper is attached at a height vertically away from the horizontal support axis of the plate material connecting one of the vertical side edges of each of the two side panels of the U-shaped material, and is constituted by a bolt whose tip abuts against the support pillar.

7. The insert steel pipe attached to the handrail installation member is a circular steel pipe that is pressurized from both sides in the diameter direction to deform the cross section into an ellipse having a minor axis and a major axis, and this steel pipe is fixedly attached to the lower end of the handrail installation member with its major axis direction perpendicular to the longitudinal direction of the safety handrail and along the width direction of the installation girder member.

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