Hook metal fitting for hanging fall prevention net

Abstract

To provide a hook metal fitting for hanging a fall prevention net, which can effectively utilize the end material of a steel plate and can be easily fixed to a steel beam by welding.SOLUTION: Provided is a hook metal fitting for hanging a fall prevention net which is fixed by welding to an upper surface 51 of the lower flange of a steel beam 50 in order to hang a fall prevention net to prevent objects, including people, from falling at a construction site where a building is constructed with steel frames. A fixed piece 10 formed by cutting out a steel plate having a required thickness with a laser to form a rectangular cross section and having a flat lower edge surface 10a provided so as to be welded and in contact with and fixed to the upper surface 51 of the lower flange and a hanging piece 20 on which the fall prevention net is hung are provided in a hook-like shape bent at an acute angle rather than a right angle.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hook fitting for hanging a fall prevention net for preventing the fall of an object including a person at a construction site where a building is constructed by a steel frame, and for fixing the hook fitting by welding to the upper surface of the lower flange of the steel frame beam.

Background Art

[0002] As a conventional hook fitting for hanging a fall prevention net, a net hanging fitting is composed of a fixing fitting and a hook member. The fixing fitting forms a pair of parallel guide flanges above and below a vertical plate portion having a body mounting hole, and hook insertion holes are formed in each guide flange. The hook member has a horizontal shaft portion, a support shaft portion that rises upward from the base end thereof and is inserted into the hook insertion holes of both guide flanges, and a hook portion that protrudes upward at the tip of the horizontal shaft portion. The fixing fitting is attached to the web portion of the steel frame beam of the building with a fastener inserted through the body mounting hole. In this attached state, the hook portion contacts the lower flange of the beam, so that it is prevented from coming off with respect to the guide flange, and the net cable is supported in a hooked state at the tip of the hook portion of the hook member (Patent Document 1).

[0003] Further, as a conventional hook fitting for hanging a fall prevention net, a plurality of second locking devices are provided at equal intervals in the longitudinal direction of the steel frame beam along the outside of the building of the steel frame beam. The second locking device has a fitting portion having a U-shaped cross section that fits into the edge portion of the lower horizontal flange of the I-shaped cross section of the steel frame beam. A bolt with a handle is screwed and penetrated through the upper surface of this fitting portion, and the penetrated tip is brought into contact with the surface of the horizontal flange. A J-shaped fitting is welded to the back of the U-shaped portion of the fitting portion (Patent Document 2).

[0004] In the above prior art, the hook fitting for hanging a fall prevention net is configured to be detachable from the steel frame beam. On the other hand, in the case of a building where it is not necessary to attach and detach the hook fitting for hanging a fall prevention net, different from the above prior art, a round bar bent into a hook shape (U shape) is used as the hook fitting for hanging a fall prevention net, and it is fixed to the upper surface of the lower flange of the steel frame beam by welding.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Regarding the problem to be solved by the hook fitting for hanging a fall prevention net, in the prior art, whether it is a type that is detachably fixed to the steel frame beam or a type that is fixed by welding a bent round bar, the fixing work is time-consuming and not easy, and there is no idea of effectively using the offcuts generated at the steel frame manufacturing site to eliminate waste.

[0007] Therefore, an object of the present invention is to provide a hook fitting for hanging a fall prevention net that can effectively utilize the offcuts of the steel plate and can be easily fixed to the steel frame beam by welding.

Means for Solving the Problems

[0008] The present invention has the following configuration in order to achieve the above object. According to one form of the hook fitting for hanging a fall prevention net according to the present invention, at a construction site where a building is constructed with a steel frame, in order to stretch a fall prevention net to prevent the fall of an object including a person, it is a hook fitting for hanging a fall prevention net that is fixed by welding to the upper surface of the lower flange of the steel frame beam. By melting and cutting a steel plate with a required thickness by a laser, a cross-section is provided in a rectangular shape, and a fixed piece portion having a flat lower side surface is provided so as to be welded and fixed in contact with the upper surface of the lower flange. The hooked piece portion on which the fall prevention net is to be hung is provided in a hook shape refracted at an acute angle rather than a right angle.

[0009] According to one form of the hook fitting for hanging a fall prevention net according to the present invention, it can be characterized in that a portion where the fixed piece portion and the hooked piece portion are continuous is provided wider than the ends of both free ends.

[0010] According to one form of the hook fitting for hanging a fall prevention net according to the present invention, it can be characterized in that a recess for preventing detachment is provided at a portion where the member forming the fall prevention net contacts and is hung on the inner angle side of the hooked piece portion.

Effect of the Invention

[0011] According to the hook fitting for hanging a fall prevention net according to the present invention, there is a particularly advantageous effect that the end material of the steel plate can be effectively utilized and it can be easily fixed to the steel frame beam by welding.

Brief Explanation of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0013] Hereinafter, a form example of a hook fitting for hanging a fall prevention net according to the present invention will be described in detail based on the drawings (FIGS. 1 to 5). The first form example is shown in FIGS. 1 to 3, and the second form example is shown in FIGS. 4 and 5. These form examples show examples of variations within the same range of technical ideas, and it goes without saying that the present invention is not limited to these form examples.

[0014] The hook fitting for hanging a fall prevention net according to the present invention is, as shown in either the first form example (FIGS. 1 to 3) or the second form example (FIGS. 4 and 5), at a construction site where a building is constructed by a steel frame, in order to stretch a fall prevention net so as to prevent the fall of an object including a person, it is a hook fitting for hanging a fall prevention net that is fixed by welding to the upper surface 51 of the lower flange of the steel frame beam 50 (see FIG. 3). Note that the steel frame beam 50 in this form example is an H-shaped steel as an example.

[0015] And, in the hook fitting for hanging a fall prevention net according to the present invention, a steel plate of a required thickness is cut out by laser welding, so that the cross section is provided in a rectangular shape (square or rectangle). Since it is laser welding, the cross section is formed in a rectangular shape, but no sharp edge is generated, and there is no need to perform a finishing process such as deburring.

[0016] Also, in the hook fitting for hanging a fall prevention net according to the present invention, a fixed piece portion 10 having a flat lower side surface 10a so as to be welded and fixed in contact with the upper surface 51 of the lower flange (see FIG. 3), and a hooked piece portion 20 on which the fall prevention net is to be hung are provided in a hook-like shape that is refracted at an angle sharper than a right angle. In the form example shown in FIGS. 1 to 5, the angle between the fixed piece portion 10 and the hooked piece portion 20 is set to 60 degrees, but it goes without saying that it is not limited to this.

[0017] According to the hook fitting for hanging a fall prevention net according to the present invention, there is a particularly advantageous effect that the end material of the steel plate can be effectively utilized and it can be easily fixed to the steel frame beam 50 by welding. That is, since the cross-sectional shape of the hook fitting for hanging a fall prevention net according to the present invention is rectangular and the lower side surface 10a of the fixed piece portion 10 is straight and flat, it can be stably placed on the upper surface 51 of the lower flange of the H-shaped steel (steel frame beam 50) in the example shown in FIG. 3, and welding work can be easily performed. Further, since it can be formed by fusing with a laser cutter device, it can be rationally produced without waste using the end material of the steel plate that would otherwise become waste material.

[0018] Further, according to the present exemplary embodiment, the portion where the fixed piece portion 10 and the hung piece portion 20 are continuous is provided wider compared to the ends of both free ends (both ends of the U-shaped form). That is, in the present exemplary embodiment, the portion where the fixed piece portion 10 and the hung piece portion 20 are continuous is continuous by the R cut 15 of the inner corner, so that the corner portion having a U-shaped form is formed wider, and the shape strength can be increased.

[0019] According to this, the strength as a hook fitting can be reasonably and sufficiently obtained. That is, since the stress applied to the root portion of the hung piece portion 20 is dispersed by the R cut 15 of the inner corner, the rigidity and strength are high. That is, it has a high shape retention property that is difficult to bend compared to the conventional form of bending a round bar, and the reliability as a hook fitting is improved.

[0020] Further, according to the present exemplary embodiment, a recess 21 for preventing detachment is provided at a portion where the member forming the fall prevention net contacts and is hung on the inner corner side of the hung piece portion 20. The shape of the recess 21 for preventing detachment is not limited to the present exemplary embodiment. For example, a plurality of small-width recesses for preventing detachment may be provided continuously to form a jagged shape to enhance the anti-slip effect, and it can be provided as appropriate.

[0021] According to this, it is possible to prevent the fall prevention net from coming off, and it is possible to suitably maintain a state in which the fall prevention net is appropriately held in a suspended state. Further, according to the recess 21 for preventing detachment of the present exemplary embodiment, it is possible to prevent the fall prevention net from being caught too much, and it is possible to hold it to such an extent that it does not interfere when withdrawing the fall prevention net. In the present exemplary embodiment, the depth of the recess 21 for preventing detachment is shallow, and the stepped portions on both sides of the recess 21 for preventing detachment are provided as R-shaped stepped portions 21a, so that the shape is such that it is possible to appropriately avoid the fall prevention net from being caught too much.

[0022] Further, on the side of the inner angle provided in the U-shape in the hook fitting for hanging the fall prevention net according to the present invention, the pointed side 16 of the next hook fitting can be sequentially inserted into the arranged state, and it is in a form that can be easily cut out by continuous laser cutting. Therefore, the steel plate material can be effectively utilized.

[0023] As described above, various preferred embodiments of the present invention have been described, but the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention.

Explanation of Reference Numerals

[0024] 10 Fixed piece part 10a Lower side surface 15 R cut of inner angle 16 Pointed side of hook fitting 20 Hanging piece part 21 Recess for preventing detachment 21a R-shaped stepped portion 50 Steel frame beam 51 Upper surface of lower flange

Claims

1. A hook fitting for hanging a fall prevention net to prevent the fall of an object including a person at a construction site where a building is constructed by a steel frame, the hook fitting being fixed by welding to the upper surface of the lower flange of the steel frame beam, by cutting and fusing a steel plate of a required thickness with a laser so that the cross section is provided in a rectangular shape, a fixed piece portion having a flat lower side surface so as to be welded and fixed in contact with the upper surface of the lower flange, and a hooked piece portion on which the fall prevention net is to be hung are provided in a hook-like shape refracted at an angle sharper than a right angle. A hook fitting for hanging a fall prevention net, characterized in that.

2. The hook fitting for hanging a fall prevention net according to claim 1, wherein a portion where the fixed piece portion and the hooked piece portion are continuous is provided wider than the ends of both free ends.

3. The hook fitting for hanging a fall prevention net according to claim 2, wherein a recess for preventing detachment is provided at a portion where the member forming the fall prevention net contacts and is hung on the inner angle side of the hooked piece portion.

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