Fixing device for fall prevention net

Abstract

To provide a fixing device for a fall prevention net, which can simplify installation while ensuring sufficient strength.SOLUTION: A fixing device (2) for a fall prevention net is used to fix the fall prevention net to the wooden structural frame of a wooden building. The fixing device (2) includes a support fixing portion (20) that is fixed to the structural frame, and a hanging portion (25) that is connected to the support fixing part (20) and hangs the fall prevention net. The support fixing portion (20) includes a through-hole (22) through which a fastener (30) for connecting to a structural frame (11) passes, and claw portions (23, 24) that protrude toward the structural frame (11) and bite into the structural frame (11).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a fastener for a fall prevention net, and more particularly to a fastener for a fall prevention net for fixing the fall prevention net to a wooden structural body of a wooden building. [Background technology]

[0002] Generally, when working at heights, such as construction work on the second floor or above and roof installation work, fall prevention nets are attached to the structural framework to prevent workers and various equipment from falling. Examples of documents disclosing techniques for attaching such fall prevention nets to structural frameworks include Japanese Patent Laid-Open No. 2005-48383 (Patent Document 1) and Japanese Patent Laid-Open No. 10-292633 (Patent Document 2).

[0003] For example, Patent Document 1 discloses a device for use in wooden buildings in which a hanging hardware for suspending a protective net is fixed to a beam with two nuts, while Patent Document 2 discloses a device for use in reinforced concrete buildings in which a net erection tool for suspending a net is fixed to a net-stretching frame with bolts and clamps. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-48383 [Patent Document 2] Japanese Patent Application Publication No. 10-292633 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, fall prevention nets and their fixing hardware are removed and reused after the work is completed. This means that the work of installing and removing the fall prevention net is doubled. On the other hand, because the fall prevention net is also intended to prevent workers from falling, it must also be strong enough to support a person.

[0006] The hanging hardware in Patent Document 1 is fixed to the beam with two nuts, while the net installation device in Patent Document 2 is connected to the net installation frame with bolts and clamps. Therefore, the technology in both documents ensures sufficient strength. On the other hand, both documents use a single hardware to secure the net in two places, which requires a great deal of effort to install and remove the fall prevention net and hardware.

[0007] The present invention has been made to solve the above-mentioned problems, and its object is to provide a fixing device for a fall prevention net that can simplify installation while ensuring sufficient strength. [Means for solving the problem]

[0008] A fixing device for a fall prevention net according to one aspect of the present invention is a fixing device for a fall prevention net for fixing the fall prevention net to a wooden structural body of a wooden building, and comprises a support fixing part that is fixed to the structural body, and a hanging part that is connected to the support fixing part and hangs the fall prevention net, and the support fixing part includes a through hole through which a fastener for connecting to the structural body passes, and a claw part that protrudes toward the structural body and bites into the structural body.

[0009] Preferably, the protruding length of the claw portion is shorter than the length of the fastener.

[0010] It is desirable that the fixing portion extends in the vertical direction along the structural body, and that the claw portion be provided above the through-hole.

[0011] Preferably, the claw portion has a generally triangular shape when viewed from the side and includes a corner portion located away from the support fixing portion, the corner portion being formed by a base portion extending perpendicular to the structural body and an oblique portion arranged at an angle relative to the base portion.

[0012] At least two or more claw portions are provided, and the two claw portions are arranged so as to sandwich the through-hole from above and below.

[0013] Preferably, the through hole is provided in the vertical center of the fixture, and the two claws are spaced apart from the through hole by the same distance. [Effects of the Invention]

[0014] According to the fastener for a fall prevention net of the present invention, it is possible to simplify installation while ensuring sufficient strength. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a location where a fixing device for a fall prevention net according to the present embodiment is attached. FIG. [Figure 2] FIG. 2 is an enlarged view of a portion of FIG. [Figure 3] 1 is a perspective view showing a fixing device for a fall prevention net according to the present embodiment. FIG. [Figure 4] 1A and 1B are diagrams showing a fixing device for a fall prevention net according to the present embodiment, in which (A) is a cross-sectional view, (B) is a plan view, and (C) is a cross-sectional view showing an enlarged claw portion. [Figure 5] FIG. 10 illustrates the behavior of a loaded fixture. [Figure 6] 10A and 10B are diagrams showing modified examples of fasteners for a fall prevention net according to the present embodiment. [Figure 7] 10A and 10B are diagrams showing another modified example of the fixing device for the fall prevention net according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which like reference numerals denote like or corresponding parts and will not be described repeatedly.

[0017] <Building Overview> Before describing the fixing device 2 for the fall prevention net according to this embodiment, an example of a building in which the fixing device 2 is installed will be described.

[0018] The building is a wooden structure, typically a wooden house. For example, when performing high-altitude work such as building floors on the second floor or above, or installing a roof, fall prevention nets 40 are installed to prevent workers and various equipment from falling. It is stipulated that the fall prevention nets 40 must be fixed to the structural frame at a specified interval.

[0019] As shown in Fig. 1, the building comprises a plurality of pillars 10 and beams 11 that are suspended horizontally across the pillars 10. A plurality of fasteners 2 are fixed to the beams 11 at predetermined intervals, such as every 1 m. The fall prevention net 40 is hung between the beams 11 by being hooked onto the plurality of fasteners 2.

[0020] The fall prevention net 40 is, for example, a horizontal net. The fall prevention net 40 includes a mesh-like net body 41 and an outer periphery rope 42 attached to the outer edge of the net body 41. From the viewpoint of preventing small equipment and the like from falling, it is preferable that the net body 41 has small mesh, such as a Russell net, but various types of nets can be used depending on the installation location.

[0021] As shown in Fig. 2, the outer periphery ropes 42 are ropes that penetrate the outer periphery of the net body 41. The outer periphery ropes 42 are hooked to a plurality of fasteners 2 fixed to the beams 11. The fasteners 2 for fixing the fall prevention net 40 to a wooden structural body such as the beams 11 will be described in detail below.

[0022] 1, the fastener 2 is described as being attached to the beam 11, but it may be attached to a wooden structural frame that constitutes a wooden building, such as a cross member such as a girder or a pillar. Therefore, in the following description, the thing to which the fastener 2 is attached will be described as the structural frame 11.

[0023] <First Embodiment> (About fixings) 2 to 4, the fixing device of the fall prevention net according to this embodiment will be described. Fixing device 2 is made of, for example, metal, and is formed by bending, for example, a rod-shaped member having a circular cross section. The vertical dimension W of fixing device 2 is, for example, 60 mm to 100 mm.

[0024] The fixing device 2 generally comprises a support fixing part 20 that is fixed to the structural body 11, and a hanging part 25 that is connected to the support fixing part 20 and hangs the fall prevention net 40. Each of the components will be described in detail below.

[0025] As shown in Fig. 4(A), the support fixing part 20 includes a main body part 21 that extends in the vertical direction along the structural body 11. As shown in Figs. 3 and 4(B), the main body part 21 has a substantially flat surface, for example, by being pressed, pressure-welded, or cut out, to facilitate attachment to the structural body 11. The main body part 21 abuts against the structural body 11, which has a flat surface.

[0026] The main body 21 includes a through hole 22 that penetrates toward the structural body 11, and claws 23, 24 that protrude toward the structural body 11 and bite into the structural body 11. The through hole 22 is preferably formed at approximately the center or higher of the fixing device 2 in the vertical direction, preferably approximately the center. A fastener 30 for fixing to the structural body 11 passes through the through hole 22. The fastener 30 is, for example, a screw with a spiral groove. The fastener 30 is screwed into the structural body 11 using, for example, a screwdriver.

[0027] The diameter W1 of fastener 30 is, for example, 2 mm or more and 5 mm or less, and typically about 4 mm. The length L1 of fastener 30 is, for example, 40 mm or more and 60 mm or less, and typically about 50 mm. Fastener 30 passes through through-hole 22 and is screwed into wooden structural body 11 using, for example, a screwdriver. Through-hole 22 is located in a position where it is sandwiched between two claws 23, 24 from above and below.

[0028] The claws 23, 24 are driven into the structural body 11 by screwing the fastener 30 into the structural body 11, and no other tools such as a hammer are required. The claws 23, 24 are made of the same metal as the main body 21, and are formed integrally with the main body 21 by welding, for example. Of the two claws, the one located above the through hole 22 will be referred to as the upper claw 23, and the one located below it will be referred to as the lower claw 24.

[0029] 4(C), the upper claw portion 23 has a generally right-angled triangular shape in a side view, and includes a corner portion 23a located away from the support fixing portion 20. The corner portion 23a has an acute angle and is formed by a base portion 23b extending perpendicular to the structural body 11 and a hypotenuse portion 23c provided at an angle relative to the base portion 23b.

[0030] The protruding dimension L2 of the upper claw portion 23 is preferably smaller than the length dimension L1 of the fastener 30, for example, between one-sixth and one-quarter. Specifically, the protruding dimension L2 of the upper claw portion 23 is between 3 mm and 10 mm, and preferably between 4 mm and 7 mm. If the protruding dimension L2 of the upper claw portion 23 is less than one-sixth of the length dimension L1 of the fastener 30, the strength of the upper claw portion 23 cannot be ensured. If the protruding dimension L2 of the upper claw portion 23 is greater than one-quarter of the length dimension L1 of the fastener 30, the upper claw portion 23 cannot be inserted into the structural body 11 simply by screwing the fastener 30. Furthermore, the vertical dimension W2 of the upper claw portion 23 is smaller than the protruding dimension L2, between approximately 2 mm and 8 mm. This allows the fastener 30 to be easily screwed in while still providing sufficient strength.

[0031] The lower claw portion 24 has substantially the same shape as the upper claw portion 23. It is preferable that the distance from the through hole 22 to the upper claw portion 23 is substantially the same as the distance from the through hole 22 to the lower claw portion 24. This allows the two claw portions 23, 24 to bite into the structural body 11 by screwing in one fastener 30.

[0032] The hooking portion 25 is provided integrally with the support fixing portion 20. The hooking portion 25 includes a first bent portion 26 continuing from the lower end of the main body portion 21, a rising portion 27 continuing from the first bent portion 26 and rising upward, a second bent portion 28 continuing from the rising portion 27 and bending downward, and a leg portion 29 continuing from the second bent portion 28 and extending downward.

[0033] 2, first bent portion 26 and rising portion 27 form a hooking portion for hooking outer peripheral rope 42 of fall prevention net 40. When outer peripheral rope 42 is removed from hanging portion 25, the mesh portion of net body 41 is caught on second bent portion 28 and leg portion 29. Therefore, second bent portion 28 and leg portion 29 form a return portion for preventing fall prevention net 40 from coming off.

[0034] It should be noted that the hooking portion 25 is only required to have a U-shaped hook portion formed by at least the first bent portion 26 and the rising portion 27, and does not necessarily have to have a return portion formed by the second bent portion 28 and the leg portion 29.

[0035] 4(B), the fixing device 2 is not provided perpendicular to the structural body 11, but is provided at an angle. This is to allow for ease of installation when the fastener 30 is passed through the through-hole 22 and screwed into the structural body 11. Therefore, the fixing device 2 may be provided perpendicular to the structural body 11, or may take various other forms.

[0036] (What happens if something falls?) 2, 5(A), and 5(B), the action on the fixing device 2 when an object falls on the fall prevention net 40 will be described.

[0037] As shown in Fig. 2, the outer rope 42 of the fall prevention net 40 is hooked at the intersection where the first bent portion 26 and the rising portion 27 of the fixing device 2 intersect. Although the outer rope 42 is not shown in Fig. 5(A) and Fig. 5(B), the intersection C shows the point where the outer rope 42 comes into contact with the fixing device 2 in the event of a falling object.

[0038] If an object falls at a location farther away than the fixing device 2 of the fall prevention net 40, first, as shown in Figure 5(A), a load is applied diagonally downward as indicated by arrow A1 to the intersection C, and then a load is applied directly downward as indicated by arrow A2. Because the lower claw portion 24 has a base portion 24b that is perpendicular to the main body portion 21, it can also withstand the downward load indicated by arrow A2.

[0039] If an object falls near the fixing device 2 of the fall prevention net 40, that is, directly below the fixing device 2, a large load will be applied to the intersection C in the downward direction indicated by arrow A3, which may cause the lower claw portion 24 to come off the structural body 11. In such a case, even if the fastener 30 comes off partway, the upper claw portion 23 has a base portion 23b that is perpendicular to the main body 21, which provides resistance when the upper claw portion 23 is pulled out. Therefore, even if an object falls directly below the fixing device 2, the fixing device 2 can be prevented from coming off the structural body 11.

[0040] Conventional fall prevention net fasteners require two screws to secure them to the structural frame in order to maintain their strength. For example, installation on the second floor of a building alone requires approximately 200 fasteners to be attached to the structural frame, resulting in approximately 400 screw fastening operations. Furthermore, fall prevention nets are often removed and reused after installation is complete, which requires the removal of the 400 screws attached to the structural frame. As such, the fasteners have been difficult to install and remove in order to ensure their strength.

[0041] In contrast, the fall prevention net fixing device 2 of this embodiment has one through-hole 22 for inserting a screw, and is provided with claws 23, 24 that bite into the structural body 11. This allows the fastener 30 to be fixed in only one location, reducing the amount of fixing work using the fixing device 30 by half compared to conventional configurations. Furthermore, since two claws 23, 24 that bite into the structural body 11 are provided in addition to one location for fixing the fastener 30, it is possible to maintain strength approximately equivalent to when screws are provided in two locations. In this way, the fall prevention net fixing device 2 of this embodiment can simplify installation while maintaining sufficient strength.

[0042] 5(A) and 5(B), the location where the load is applied to the fixing device 2 is the intersection C shown in FIG. 5(A) and FIG. 5(B), so by arranging the position of the claw portion 23 above the connection point of the fastener 30, the fixing device 2 is less likely to come off from the structural body 11. Furthermore, by making the protruding length of the claw portions 23, 24 shorter than the length of the fastener 30, it becomes possible for the claw portions 23, 24 to bite into the structural body 11 simply by screwing the fastener 30 in.

[0043] The claws 23, 24 are shaped like a roughly right-angled triangle when viewed from the side, and bases 23b, 24b that extend perpendicular to the structural body 11 are provided below, so even if a load on the fastener 2 due to a fallen object is applied to the intersection C, this provides resistance to movement in the direction of the load, making it difficult for the fastener 2 to come loose. Furthermore, because bases 23b, 24b extend perpendicular to the structural body 11, the claws can be easily screwed into the structural body.

[0044] <About modified examples> 6 and 7 are diagrams showing modified examples of the fixture. Modified examples of the fixture will be described with reference to FIGS.

[0045] In the above embodiment, two claw portions 23, 24 are provided above and below through-hole 22, but it is sufficient to provide at least one above through-hole 22. Specifically, claw portion 23A is preferably provided away from through-hole 22, more specifically, at a distance of 10 mm or more, and from the viewpoint of strength, is preferably provided near the upper edge of main body portion 21.

[0046] Furthermore, even when two claws are provided, as in the case of claws 23 and 24 in this embodiment, they do not have to be provided above and below across through-hole 22. For example, as shown in Fig. 7, two claws 23A and 24A may be arranged above through-hole 22 and aligned in the vertical direction.

[0047] Furthermore, when three or more claw portions are provided, three may be provided above the through-hole 22, or two may be located above the through-hole 22 and one may be located below the through-hole 22. In this way, when multiple claw portions are provided, various arrangements may be adopted.

[0048] The above-described embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined by the claims. Furthermore, all modifications within the scope and meaning equivalent to the claims are included. [Explanation of symbols]

[0049] 2 Fixing device, 11 Beam (structural body), 20 Support fixing part, 22 Through hole, 23 Upper claw part, 24 Lower claw part, 23a Corner part, 23b, 24b Bottom part, 23c Slant part, 25 Hanging part, 30 Fastener, 40 Fall prevention net.

Claims

1. A fixing device for a fall prevention net for fixing the fall prevention net to the wooden structural body of a wooden building, a support fixing portion fixed to the structural body; a hooking portion connected to the support fixing portion and for hanging the fall prevention net; The support and fixing portion is a fixing device for a fall prevention net, and includes a through hole through which a fastener for connecting to the structural body passes, and a claw portion that protrudes toward the structural body and digs into the structural body.

2. The fixing device for a fall prevention net according to claim 1 , wherein the protruding length of the claw portion is shorter than the length of the fastener.

3. The support fixing portion extends in the up-down direction along the structural body, The fixing device for a fall prevention net according to claim 1 or 2, wherein the claw portion is provided above the through hole.

4. The claw portion has a generally triangular shape in a side view and includes a corner portion located away from the support fixing portion, 3. A fixing device for a fall prevention net according to claim 1 or 2, wherein the corner portion is formed by a base portion extending perpendicular to the structural body and an oblique side portion provided at an angle to the base portion.

5. At least two or more of the claw portions are provided, The fixing device for a fall prevention net according to claim 1 or 2, wherein the two claw portions are arranged so as to sandwich the through hole from above and below.

6. The through hole is provided in the center of the fixing device in the up-down direction, The fastener for a fall prevention net according to claim 5 , wherein the two claw portions are spaced apart from the through-hole by the same distance.

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