Getting caught prevention tool

Abstract

To provide a getting caught prevention tool capable of preventing an external wire such as an electric cable from getting caught on a hook when lifting a suspended load using the existing hook.SOLUTION: A getting caught prevention tool 30 is attached to a hook 20 with a hook-shaped hook body 21 to prevent external wires such as an electric wire being caught by the hook body 21. The getting caught prevention tool 30 comprises a hook part 31 hooked on a neck part 21a of the hook body 21, and an opening / closing part 32 with a base end part attached to the hook part 31 via a pivot shaft 39, opening / closing an opening 25 of the hook body 21 by pivoting in the vertical direction centered on the pivot shaft 39. The opening / closing part 32 forms the closed state closing the opening 25 when the tip side of the opening / closing part abuts on a tip part 21b of the hook body 21 from above.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a snag prevention device that is attached to the hook of a crane or the like and prevents electric wires or the like from getting caught on the hook. [Background technology]

[0002] At construction sites, loads such as construction materials are lifted using a crane and moved to a designated location. In this case, a sling connected to the load is hooked onto the crane hook, and the load is then lifted by the crane in this hooked state.

[0003] When a load is being lifted by a crane, if there are electric wires or the like nearby, the electric wires or the like may get caught on the hook. In consideration of this issue, Patent Document 1 discloses a hook equipped with a snag prevention function that prevents electric wires or the like from getting caught on the hook. The hook in Patent Document 1 includes a hook-shaped hook portion for attaching the load and an anti-snag plate extending from the neck (base end) of the hook portion to the tip end. The anti-snag plate is rotatably attached to a pivot shaft provided on the neck end of the hook portion and rotates vertically around the pivot shaft to open and close the opening of the hook portion. Furthermore, the anti-snag plate normally abuts against the tip end of the hook portion from above, closing the opening. This prevents electric wires or the like from entering the hook portion through the opening when a load is being lifted by a crane, thereby preventing electric wires or the like from getting caught on the hook portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 60-75378 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the hook in Patent Document 1 is configured as a hook with an anti-snap plate attached. Therefore, when trying to add an anti-snap function to an existing hook, the technology in Patent Document 1 cannot be applied. Therefore, there is a need for a technology that prevents electric wires and the like from getting caught on the hook when using an existing hook to lift a load.

[0006] The present invention has been made in consideration of the above circumstances, and its main object is to provide a snagging prevention device that can prevent external wires such as electric wires from getting caught on a hook when lifting a load using an existing hook. [Means for solving the problem]

[0007] In order to solve the above problems, the anti-snag device of the first invention is attached to a hook having a hook-shaped hook body and prevents external wires such as electric wires from getting caught on the hook body, and comprises a hanging part that is hung on the neck part of the hook body, and an opening / closing part whose base end is attached to the hanging part via a pivot shaft and which opens and closes the opening of the hook body by pivoting in an up and down direction around the pivot shaft, and the opening / closing part is placed in a closed state in which it closes the opening by abutting its tip side against the tip part of the hook body from above.

[0008] The anti-snag device of the first invention has a hook that can be hung on the neck of the hook body. In this case, the anti-snag device can be attached to the hook by hanging the hook on the neck. This makes it possible to attach the anti-snag device to an existing hook.

[0009] The anti-snag device also has an opening / closing part whose base end is attached to the hanging part via a pivot shaft. The opening / closing part opens and closes the opening of the hook body by pivoting up and down around the pivot shaft. The opening / closing part enters a closed state, closing the opening, when its tip abuts the tip of the hook body from above. In this case, when lifting a load using the hook, it is possible to prevent external wires such as electric wires from getting inside the hook body through the opening of the hook body. This makes it possible to prevent external wires from getting caught on the hook (hook body) when lifting a load using an existing hook.

[0010] When attaching or detaching a load to or from the hook body, the opening of the hook body is opened by rotating the opening / closing part, which is in the closed state, upward, and the load is then attached or detached through the opened opening.

[0011] The anti-snag device of the second invention is the same as that of the first invention, and is provided with a biasing member connected to the hanging portion and the opening / closing portion, respectively, which biases the opening / closing portion to rotate downward relative to the hanging portion, and the biasing force of the biasing member presses the tip side of the opening / closing portion in the closed state against the tip portion of the hook body.

[0012] According to the second aspect of the present invention, the anti-snag device includes a biasing member connected to the hanging portion and the opening-closing portion, and biasing the opening-closing portion downward relative to the hanging portion. In this case, the biasing force of the biasing member presses the tip of the opening-closing portion in the closed state against the tip of the hook body from above. This reliably maintains the closed state of the opening-closing portion, thereby reliably preventing the external wire from getting caught on the hook body.

[0013] The anti-snag device of the third invention is the second invention, wherein the hook body is bent backward below the neck portion and extends in an approximately C-shape from the bent portion toward a tip portion located forward of the neck portion, and the biasing member biases the hanging portion to rotate downward relative to the opening / closing portion when the opening / closing portion is in the closed state, and the hanging portion is pressed against the bent portion by the biasing force of the biasing member when hung on the neck.

[0014] According to the third aspect of the present invention, when the hook is hung on the neck, the hook is urged downward by the urging member and pressed against the bent portion of the hook body, thereby allowing the hook, and therefore the anti-hook device, to be attached to the hook in a stable state.

[0015] The anti-snag device of the fourth invention is any of the first to third inventions, wherein the pivot shaft is a first pivot shaft, the hook has a base end attached to the neck portion via a second pivot shaft, and has a latch that opens and closes the opening by pivoting around the second pivot shaft inside the hook body, and a latch biasing portion that biases the latch so that the tip of the latch abuts the inner periphery of the tip side of the hook body to close the opening, and the first pivot shaft is positioned so as to be located above the second pivot shaft.

[0016] Some hooks are equipped with a latch that prevents a load hung from the hook from coming off. The base end of the latch is attached to the neck of the hook body via a pivot shaft and rotates inside the hook body to open and close the opening of the hook body. The latch is also biased by a latch biasing part so that its tip abuts against the inner periphery of the tip side of the hook body, closing the opening of the hook body in this abutting state.

[0017] In the above-described hook with a latch, when a load is attached to or detached from the hook body, the latch must be rotated inward of the hook body (more specifically, in the direction in which the tip of the latch moves away from the inner periphery of the tip side of the hook body) against the biasing force of the latch biasing part to open the opening of the hook body. Therefore, when attaching an anti-snag device to a hook with a latch, when a load is attached or detached, the opening of the hook body must be opened by rotating the opening / closing part of the anti-snag device outward (in other words, upward) from the hook body and rotating the latch inward from the hook body. Here, when rotating the opening / closing part and the latch in this way, it is conceivable to insert a finger between the opening / closing part and the latch to perform the rotation operation.

[0018] In view of this, in the fourth invention, the rotation axis (first rotation axis) of the opening / closing unit is positioned higher than the rotation axis (second rotation axis) of the latch. In this case, a space for inserting a finger between the opening / closing unit and the latch can be suitably secured. Therefore, when inserting a finger between the opening / closing unit and the latch to rotate the opening / closing unit and the latch, the operation can be easily performed. This makes it easier to attach and detach a suspended load to and from a hook with a latch.

[0019] The anti-snag device of the fifth invention is any of the first to third inventions, wherein the opening / closing part has a pair of clamping plate parts that, when abutted against the tip of the hook body from above, extend downward beyond the abutting point and are arranged to clamp the tip of the hook body from both sides.

[0020] According to the fifth aspect of the present invention, when the opening-closing part abuts against the tip of the hook body from above (i.e., when the opening-closing part is in the closed state), the pair of clamping plates are arranged to clamp the tip of the hook body from both sides. This prevents the opening-closing part from shifting sideways from the tip of the hook body when the opening-closing part is in the closed state. Therefore, the closed state of the opening-closing part can be maintained more reliably.

[0021] The anti-snag device of the sixth invention is any of the first to third inventions, wherein the hook is connected to the upper side of the neck and has a connecting part to which a linear member such as a wire rope is connected, and the hanging part has an insertion part through which the neck part is inserted, and the insertion part can be passed through the connecting part.

[0022] According to the sixth aspect of the present invention, the connecting part of the hook connected to the upper side of the neck part can be passed through the insertion part of the hanging part, through which the neck part of the hook body is inserted. In this case, when hanging the hanging part on the neck part of the hook body, the connecting part can be passed through the insertion part and the hanging part can be hung on the neck part from above the hook. This makes it easy to attach the snag prevention device to the hook. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 shows a building unit being lifted using a crane at a construction site. [Figure 2] (a) is a side view of the hook, and (b) is a front view of the hook. [Figure 3] (a) is a plan view of the anti-snag device, (b) is a side view of the anti-snag device, and (c) is a front view of the anti-snag device. [Figure 4] 1(a) is a side view showing a state in which the anti-hook device is attached to the hook, and FIG. 1(b) is a front view showing the same state. DETAILED DESCRIPTION OF THE INVENTION

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 shows a building unit being lifted using a crane at a construction site.

[0025] As shown in Figure 1, at a construction site where a modular building is being constructed, the rectangular parallelepiped building units 11 that make up the modular building are lifted using a crane K and moved in this lifted state to a predetermined installation location. Wire ropes 14 are connected to the upper end of the building unit 11 via eyebolts (not shown) at its four corners, and each of these wire ropes 14 is connected to a common ring 15.

[0026] A hook 20 is suspended from the crane K via a wire rope 16. A ring 15 (corresponding to a lifting device) is hung on the hook 20, and a building unit 11 (corresponding to a suspended load) is hung on the ring 15. In this state, the building unit 11 can be lifted by the crane K.

[0027] Next, the configuration of the hook 20 will be described with reference to Fig. 2. Fig. 2(a) is a side view of the hook 20, and Fig. 2(b) is a front view of the hook 20. In Fig. 2(a), the left-right direction of the paper surface corresponds to the front-rear direction of the hook 20, and the depth direction of the paper surface corresponds to the left-right direction of the hook 20. In Fig. 2(a), the right side of the paper surface corresponds to the front side, and the left side of the paper surface corresponds to the rear side.

[0028] As shown in FIGS. 2(a) and 2(b), hook 20 is a metal eye hook (hook with a loop). Hook 20 has hook-shaped hook body 21 and eye portion 22 connected to the upper side of neck portion 21a of hook body 21. Hook body 21 is a portion on which a hanging device such as ring 15 is hung. Hook body 21 has bent portion 21c bent backward below neck portion 21a. Hook body 21 extends in a generally C-shape from bent portion 21c toward tip portion 21b, which is located forward and below neck portion 21a. Hook body 21 also has an opening 25 formed between neck portion 21a and tip portion 21b. A hanging device is hung on hook body 21 through this opening 25.

[0029] The eye portion 22 has an annular shape and is formed integrally with the hook body 21. The wire rope 16 extending from the crane K is connected to the eye portion 22. The eye portion 22 corresponds to the "connecting portion."

[0030] The hook 20 is provided with a latch 26 for preventing a hanging device hung on the hook body 21 from coming off the hook body 21. Therefore, the hook 20 of this embodiment is what is known as a hook with a latch. The base end of the latch 26 is attached to the neck portion 21a of the hook body 21 via a pivot shaft 27. The pivot shaft 27 is an axis that extends in the left-right direction. This allows the latch 26 to rotate around the pivot shaft 27 inside the hook body 21, and this rotation opens and closes the opening 25. The pivot shaft 27 corresponds to the "second pivot shaft."

[0031] The hook 20 is provided with a torsion spring 29 serving as a latch biasing member around the pivot shaft 27. The torsion spring 29 biases the latch 26 to rotate so that the tip of the latch 26 abuts against the inner periphery of the hook body 21 at the tip end. Due to the biasing force of the torsion spring 29, the tip of the latch 26 is always in abutment with the inner periphery of the hook body 21 at the tip end, thereby keeping the opening 25 of the hook body 21 closed by the latch 26. On the other hand, when the latch 26 is rotated inward of the hook body 21 against the biasing force of the torsion spring 29, the tip of the latch 26 moves away from the inner periphery of the hook body 21, opening the opening 25 of the hook body 21 (see the two-dot chain line in FIG. 2( a)). For convenience, the torsion spring 29 is not shown in FIG. 2( b).

[0032] When lifting a building unit 11 using a crane K at a construction site, external wires such as electric wires may be present in the vicinity. In such a case, there is a risk that the external wires may get caught on the hook 20 (more specifically, the hook body 21) of the crane K. In view of this, in this embodiment, a snagging prevention device 30 that prevents the external wires from getting caught on the hook 20 is attached to the hook 20. The configuration of the snagging prevention device 30 will be described below with reference to FIG. 3. In FIG. 3, (a) is a plan view of the snagging prevention device 30, (b) is a side view of the snagging prevention device 30, and (c) is a front view of the snagging prevention device 30. In addition, FIG. 4 is a side view showing the state in which the snagging prevention device 30 is attached to the hook 20, and (b) is a front view showing the same state.

[0033] In the following description, the front-rear direction is based on the state in which the anti-entrapment device 30 is attached to the hook 20. Therefore, in Figures 3(b) and 4(a), the left-right direction of the paper is the front-rear direction, and the depth direction of the paper is the left-right direction, just like Figure 2(a).

[0034] As shown in Figures 3(a) to (c) and 4(a) and (b), the anti-snag device 30 comprises a hanging part 31 that is hung on the neck part 21a of the hook body 21, and an opening / closing part 32 that opens and closes the opening 25 of the hook body 21.

[0035] The hanging portion 31 has a pair of opposing plate portions 34 extending in the front-rear direction and facing each other, and a pair of connecting portions 35, 36 connecting the opposing plate portions 34. The pair of opposing plate portions 34 and the pair of connecting portions 35, 36 form the hanging portion 31 in a substantially rectangular frame shape, in other words, a square ring shape. An opening that is open in the vertical direction is formed inside the hanging portion 31. This opening serves as an insertion portion 38 through which the neck portion 21a of the hook body 21 is inserted. The hanging portion 31 is hung on the neck portion 21a with the neck portion 21a inserted through this insertion portion 38.

[0036] The eye 22 of the hook 20 can be passed through the insertion portion 38. As a result, when hanging the hanging portion 31 on the neck portion 21a, the eye 22 can be passed through the insertion portion 38 of the hanging portion 31. When removing the hanging portion 31 from the neck portion 21a, the eye 22 can be passed through the insertion portion 38 of the hanging portion 31. In this way, by hanging the hanging portion 31 on or removing it from the neck portion 21a, the hanging portion 31 and therefore the anti-snag device 30 can be detachably attached to the hook 20.

[0037] The pair of opposing plates 34 are formed from a strip-shaped steel plate. Specifically, the pair of opposing plates 34 are bent in a stepped manner at their rear ends so that the distance between them narrows. Of the pair of connecting portions 35, 36, the connecting portion 35 connects the rear ends of the opposing plates 34, and the connecting portion 36 connects the front ends of the opposing plates 34. The connecting portion 35 includes a cylindrical spacer 35a disposed between the opposing plates 34, and a bolt 35b and nut 35c that fasten the opposing plates 34 together via the spacer 35a. The bolt 35b is inserted inside the spacer 35a and fastened to the nut 35c in the inserted state. The connecting portion 36 is formed from a steel plate and fixed to each opposing plate 34 by welding.

[0038] The hook portion 31 has a straight portion 31a that extends linearly in the front-to-rear direction as a whole, and a curved portion 31b that is curved upward from the straight portion 31a and forward of the straight portion 31a. The straight portion 31a includes the front end of the hook portion 31, and the curved portion 31b includes the rear end of the hook portion 31. Since the hook portion 31 has the curved portion 31b, the front end of the hook portion 31 is located higher than the rear end of the hook portion 31. In addition, the curved portion 31b is curved so as not to cover the hole on the inside of the eye portion 22 from the side.

[0039] A rotation shaft 39 extending in the left-right direction is provided at the front end of the hanging portion 31. The rotation shaft 39 is provided to bridge over each of the opposing plate portions 34. The rotation shaft 39 is disposed so as to be located higher than the rotation shaft 27 of the latch 26 provided on the hook 20. The rotation shaft 39 corresponds to the "first rotation shaft."

[0040] The opening-closing part 32 has a longitudinal shape extending from a base end to a tip end in a side view. The base end of the opening-closing part 32 is attached to the hanging part 31 via a rotation shaft 39. This allows the opening-closing part 32 to rotate in the vertical direction around the rotation shaft 39, and this rotation opens and closes the opening 25 of the hook body 21. The opening-closing part 32 is able to rotate in the vertical direction outside the hook body 21. When the tip side of the opening-closing part 32 abuts against the tip part 21b of the hook body 21 from above, it enters a closed state in which it closes the opening 25.

[0041] The opening-closing part 32 is made of steel plate and has a U-shaped cross section. The opening-closing part 32 has an upper plate part 32a extending in the longitudinal direction thereof and a pair of side plate parts 32b extending downward (more specifically, in a downward direction perpendicular to the longitudinal direction of the opening-closing part 32) from both ends of the upper plate part 32a in the width direction. The upper plate part 32a has an abutment part 41 at its tip end that abuts against the tip end part 21b of the hook body 21 from above. When this abutment part 41 abuts against the tip end part 21b, the opening-closing part 32 is placed in a closed state.

[0042] Each side plate portion 32b has a sandwiching plate portion 42 at its tip end that extends downward beyond the abutting portion 41 when the opening / closing portion 32 is in the closed state and is positioned to sandwich the tip end portion 21b of the hook body 21 from both sides. The sandwiching plate portion 42 of each side plate portion 32b is positioned close to the tip end portion 21b of the hook body 21. In addition, the sandwiching plate portion 42 of each side plate portion 32b has rounded corners on its lower end side.

[0043] One end of a coil spring 43 is connected to the hanging portion 31, and the other end of the coil spring 43 is connected to the opening-closing portion 32. One end of the coil spring 43 is connected to the connecting portion 36 of the hanging portion 31, and the other end of the coil spring 43 is connected to the opening-closing portion 32 via a shaft portion 45. The elastic force of the coil spring 43 biases the opening-closing portion 32 to rotate downward relative to the hanging portion 31. As a result, when the opening-closing portion 32 is in the closed state, the biasing force of the coil spring 43 presses the opening-closing portion 32 against the tip portion 21b of the hook body 21. The coil spring 43 corresponds to the "biasing member." For convenience, the coil spring 43 is not shown in Figures 3(a), (c), and 4(b).

[0044] When the opening / closing part 32 is in the closed state, the biasing force of the coil spring 43 biases the hook part 31 to rotate downward relative to the opening / closing part 32. As a result, the hook part 31 is hooked on the neck part 21a of the hook body 21 and pressed against the bent part 21c on the lower side of the neck part 21a.

[0045] Next, a description will be given of the operation of the anti-snap device 30. Here, the operation when the building unit 11 is hung from the hook 20 to which the anti-snap device 30 is attached and lifted up by the crane K will be described.

[0046] First, a slinging operation is performed in which the building unit 11 is hung on the hook body 21 of the hook 20 via the ring 15. In the slinging operation, first, the opening / closing part 32 of the anti-snag device 30 is rotated upward (in other words, outward from the hook body 21) against the biasing force of the coil spring 43 (see the two-dot chain line in Figure 4(a)), and the latch 26 of the hook 20 is rotated inward from the hook body 21 against the biasing force of the torsion spring 29, thereby opening the opening 25 of the hook body 21. In this case, a finger is inserted into the space between the latch 26 and the opening / closing part 32, and the latch 26 and the opening / closing part 32 are rotated individually.

[0047] Next, with the opening 25 of the hook body 21 open, the building unit 11 (more specifically, the ring 15) is hooked onto the hook body 21 through the opening 25. After that, the fingers are removed from the latch 26 and the opening / closing part 32. As a result, the latch 26 rotates to a position where it closes the opening 25 due to the biasing force of the torsion spring 29, and the opening / closing part 32 rotates to a position where it closes the opening 25 due to the biasing force of the coil spring 43. As a result, the opening 25 of the hook body 21 is closed by the latch 26 and the opening / closing part 32.

[0048] Next, the building unit 11 is lifted by the crane K. In this case, the opening 25 of the hook body 21 is closed by the opening / closing part 32, so even if external wires such as electric wires are present in the vicinity, the external wires are prevented from entering the inside of the hook body 21 through the opening 25. This makes it possible to prevent the external wires from getting caught on the hook body 21 when lifting the building unit 11.

[0049] According to the configuration of this embodiment described above in detail, the following excellent effects can be obtained.

[0050] The anti-snag device 30 has a hook 31 that can be hooked onto the neck 21a of the hook body 21. Therefore, by hooking the hook 31 onto the neck 21a, the anti-snag device 30 can be attached to an existing hook 20. The anti-snag device 30 also has an opening / closing part 32 whose base end is attached to the hanging part 31 via a pivot 39. The opening / closing part 32 opens and closes the opening 25 of the hook body 21 by pivoting vertically around the pivot 39. The opening / closing part 32 enters a closed state, closing the opening 25, when its tip abuts the tip 21b of the hook body 21 from above. In this case, as described above, when lifting a building unit 11 using the hook 20, it is possible to prevent surrounding external wires from entering the interior of the hook body 21 through the opening 25 of the hook body 21. This makes it possible to prevent external wires from getting caught on the hook 20 when lifting a building unit 11 using an existing hook 20.

[0051] The anti-snag device 30 is equipped with a coil spring 43 that is connected to the hanging portion 31 and the opening-closing portion 32, respectively, and that urges the opening-closing portion 32 to rotate downward relative to the hanging portion 31. In this case, the urging force of the coil spring 43 presses the tip side of the opening-closing portion 32, which is in the closed state, from above against the tip portion 21b of the hook body 21. This ensures that the closed state of the opening-closing portion 32 can be maintained, and as a result, it is possible to reliably prevent the external wire from getting caught on the hook body 21.

[0052] When the opening-closing part 32 is in the closed state, the hook part 31 is urged by the coil spring 43 to rotate downward relative to the opening-closing part 32. As a result, with the hook part 31 hooked on the neck part 21a, the hook part 31 is urged downward by the coil spring 43 and pressed against the bent part 21c of the hook body 21. Therefore, the hook part 31 and therefore the anti-entrapment device 30 can be attached to the hook 20 in a stable state.

[0053] If an external wire gets caught on the hook 20 with the latch 26, it is thought that the presence of the latch 26 makes it extremely difficult to remove the external wire from the hook 20 (hook body 21). In this regard, in the above embodiment, the anti-hooking device 30 is attached (post-installed) to the hook 20 with the latch 26, so that the external wire can be prevented from getting caught on the hook 20 with the latch 26, and as a result, the above-mentioned problem of it being difficult to remove the external wire from the hook 20 can be avoided.

[0054] During slinging work, in order to open the opening 25 of the hook body 21, it is necessary to insert a finger between the opening / closing part 32 and the latch 26 and rotate the opening / closing part 32 and the latch 26. In this regard, in the above embodiment, the rotation axis 39 of the opening / closing part 32 is positioned higher than the rotation axis 27 of the latch 26, so that a space for inserting a finger can be suitably secured between the opening / closing part 32 and the latch 26. Therefore, it is possible to easily insert a finger into the space and rotate the opening / closing part 32 and the latch 26.

[0055] When the opening-closing part 32 abuts against the tip part 21b of the hook body 21 from above (i.e., when the opening-closing part 32 is in the closed state), the pair of clamping plates 42 provided on the opening-closing part 32 are positioned to clamp the tip part 21b of the hook body 21 from both sides. This makes it possible to prevent the opening-closing part 32 from shifting laterally from the tip part 21b of the hook body 21 when the opening-closing part 32 is in the closed state. This makes it possible to more reliably maintain the closed state of the opening-closing part 32.

[0056] The corners of the clamping plate 42 on its lower end (tip side) are rounded, which prevents the external wire from getting caught on the opening-closing part 32 and unintentionally lifting the opening-closing part 32. In addition, the clamping plate 42 is angled along the front surface of the tip part 21b of the hook body 21, which also makes it possible to achieve the above-mentioned effect.

[0057] The insertion portion 38 of the hanging portion 31 can accommodate not only the neck portion 21a of the hook body 21 but also the eye portion 22 of the hook 20 connected to the upper side of the neck portion 21a. In this case, when hanging the hanging portion 31 on the neck portion 21a of the hook body 21, the eye portion 22 can be passed through the insertion portion 38 and the hanging portion 31 can be hung on the neck portion 21a of the hook 20 from above. This makes it possible to easily attach the anti-snag device 30 to the hook 20.

[0058] The present invention is not limited to the above-described embodiment, and may be implemented, for example, as follows.

[0059] The hook 20 in the above embodiment is an eye hook type in which the connecting portion is the eye portion 22, but there are various types of hooks, such as a shank hook type in which the connecting portion is the shank portion. The anti-snag device 30 can also be applied to these hooks.

[0060] If the connecting portion of the hook 20 is large, it may be impossible to pass the connecting portion through the insertion portion 38 of the hanging portion 31. In this case, the bolts 35b and nuts 35c of the connecting portion 35 of the hanging portion 31 may be loosened or removed to increase the spacing between the opposing plate portions 34, and in this state, the connecting portion of the hook 20 may be passed between the opposing plate portions 34 while the hanging portion 31 is hung on the neck portion 21a of the hook body 21.

[0061] In the above embodiment, the anti-snag device 30 is provided with the coil spring 43 that urges the opening-closing part 32 to rotate downward relative to the hanging part 31, but it is also possible to not provide such a coil spring 43. In this case, the opening-closing part 32 is urged to rotate downward by its own weight, thereby being brought into the closed state.

[0062] In the above embodiment, the anti-snap device 30 is attached to the hook 20 with the latch 26, but the anti-snap device 30 may be attached to a hook without a latch. [Explanation of symbols]

[0063] 20...hook, 21...hook body, 21a...neck portion, 21b...tip portion, 21c...bent portion, 22...eye portion as connecting portion, 25...opening, 26...latch, 27...rotating shaft as second rotating shaft, 29...torsion spring as latch biasing portion, 30...anti-snag device, 31...hanging portion, 32...opening / closing portion, 38...insertion portion, 39...rotating shaft as first rotating shaft, 42...clamping plate portion, 43...coil spring as biasing member.

Claims

1. A snagging prevention device that is attached to a hook having a hook-shaped hook body and prevents an external wire such as an electric wire from getting caught on the hook body, a hook portion that can be hung on the neck portion of the hook body; an opening / closing part whose base end is attached to the hanging part via a pivot shaft and which opens and closes the opening of the hook body by pivoting in the vertical direction around the pivot shaft; The opening / closing part is in a closed state in which the tip side thereof abuts against the tip portion of the hook body from above, thereby closing the opening, and is an anti-snag device.

2. a biasing member connected to the hanging portion and the opening / closing portion, respectively, for biasing the opening / closing portion downward relative to the hanging portion; The snagging prevention device according to claim 1, wherein the biasing force of the biasing member presses the tip side of the opening / closing part in the closed state against the tip part of the hook body.

3. the hook body is bent rearward below the neck portion and extends in a generally C-shape from the bent portion toward a tip portion located forward of the neck portion, the biasing member biases the hook portion downward relative to the opening-closing portion when the opening-closing portion is in the closed state, The snagging prevention tool according to claim 2 , wherein the hook portion is pressed against the bent portion by the biasing force of the biasing member while being hooked on the neck portion.

4. the rotation axis is a first rotation axis, The hook is a latch whose base end is attached to the neck portion via a second pivot shaft and which opens and closes the opening by pivoting around the second pivot shaft inside the hook body; a latch biasing portion that biases the latch so that the tip end of the latch abuts against the inner peripheral portion of the tip end side of the hook body to close the opening, The snagging prevention tool according to claim 1 , wherein the first rotation shaft is disposed so as to be positioned above the second rotation shaft.

5. 4. The anti-hook device according to claim 1, wherein the opening / closing part has a pair of clamping plate parts that, when abutted against the tip of the hook body from above, extend downward beyond the abutting point and are arranged to clamp the tip of the hook body from both sides.

6. the hook has a connecting portion connected to an upper side of the neck portion and to which a linear member such as a wire rope is connected, The hanging portion has an insertion portion through which the neck portion is inserted, The snagging prevention device according to claim 1 , wherein the connecting portion can be passed through the insertion portion.

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