Hook for safety belt

Abstract

To provide a hook for a safety belt, enabling smooth opening / closing operation by securing an effective diameter of a hook part and holding rigidity in a front-back direction of an aperture.SOLUTION: A hook 1 for a safety belt includes: a hook-shaped hook body 2 having an engagement side opening 3 on the front; a stopper 4 for directly opening / closing the engagement side opening 3; an opening / closing lever 5 for operating opening / closing of the engagement side opening 3 by interlocking the stopper 4; a lock bar 6 provided from the stopper 4 to the backward side of the hook body 2; and a lock mechanism 7 for controlling sliding of the lock bar 6. The lock bar 6 is fixed by the lock mechanism 7, which makes the lock bar 6 support the stopper 4 at a closed position.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hook used for fastening a lifeline of a safety belt, which prevents a worker from falling, to a fixed structure at a work site at height. [Background technology]

[0002] Safety belts worn by workers at high-altitude work sites come in various types, including harnesses and waist belts. All types of safety belts are connected to a lifeline, and a hook attached to the end of the lifeline is fastened to a fixed structure to prevent the worker from falling and ensure safety. In the safety belt hook described in Patent Document 1, a hook capable of locking a stopper has been invented to prevent the hook from opening and coming off due to an unexpected incident.

[0003] Generally, a hook with a similar structure opens the opening by gripping the unlocking handle and the stopper together with the hook body, and engages with the structure. Therefore, the user's finger hanging on the middle part of the stopper may block part of the opening, which may get in the way when engaging or detaching the hook from the fixing structure. Therefore, Patent Document 2 describes a safety belt hook in which the shape of the stopper is curved so that the user's finger does not get in the way. Also, Patent Document 3 describes a safety belt hook in which the effective diameter of the hook can be secured by opening and closing the stopper without putting a hand on the stopper itself.

[0004] However, while typical safety ropes used to prevent falls when working at height are equipped with safety belt hooks with a maximum diameter of 50 mm, there are fixing structures that are larger than the maximum diameter of typical safety belt hooks (hereinafter referred to as conventional hooks), such as railway overhead line equipment that uses equal leg angle irons of 75 mm, and it is sometimes impossible to directly attach conventional hooks.

[0005] Therefore, Patent Document 4 describes a safety belt hook that has a large opening dimension and allows the stopper to be operated via a link member by operating an opening / closing lever, eliminating the need to grip the stopper itself as with conventional hooks and preventing the worker's fingers from blocking part of the opening on the locking side of the hook. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-031687 [Patent Document 2] JP 2007-117573 A [Patent Document 3] JP 2017-108822 A [Patent Document 4] JP 2020-69125 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the safety belt hook in Patent Document 4 has a problem in that when stress is applied in the fore-and-aft direction due to the widened aperture, the rigidity in the fore-and-aft direction is insufficient, causing the hook to bend significantly and making it difficult to open and close the hook smoothly.

[0008] Therefore, an object of the present invention is to provide a hook for a safety belt that ensures an effective diameter of the hook portion and maintains rigidity of the opening in the front-to-rear direction when the hook is closed, thereby enabling smooth opening and closing operations. [Means for solving the problem]

[0009] In order to achieve the above object, the invention described in claim 1 is a safety belt hook provided with a hook-shaped hook body having a locking side opening at the front, and a stopper connected to the lower end of the hook body and movable between a closing position where it stands upright to close the locking side opening and an opening position where it falls backward to open the locking side opening, and further provided with an opening / closing lever whose lower end is connected to the lower part of the hook body so as to be rotatable in the front-rear direction at a position rearward of the stopper and inside the hook body, a lock bar which extends rearward from the upper end of the stopper towards the hook body at the closing position, and The locking mechanism is provided on the lock main body and is switchable between a locked state in which, in a closed position, the locking mechanism engages with the rear end of the locking bar to restrict rearward movement of the locking bar, and an released state in which the locking mechanism does not engage with the rear end of the locking bar and allows rearward movement of the locking bar. The opening / closing lever is connected to the stopper so that the stopper moves in conjunction with the rotation of the opening / closing lever. When the locking mechanism is in the released state, when the stopper is moved from the closed position to the open position by the opening / closing lever, the locking bar moves together with the stopper to retreat to the rear side of the engagement side opening. The invention described in claim 2 is characterized in that, in the invention described in claim 1, when the stopper moves from the closed position to the open position, the lock bar penetrates the hook body, slides within the hook body, and assumes a posture aligned with the hook body at the closed position. Furthermore, the invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the opening / closing lever is connected to the stopper via a link member so that the stopper moves in conjunction with the rotation of the opening / closing lever. Effect of the Invention

[0010] According to the present invention, the safety belt hook includes a hook-shaped hook body having a locking side opening, a stopper for directly opening and closing the locking side opening, an opening / closing lever for moving the stopper, and a lock bar extending rearward from the upper end of the stopper toward the hook body when the stopper is in the closed position. The lock bar moves to retreat toward the rear side of the locking side opening when the stopper moves from the closed position to the open position. Therefore, when the locking side opening of the safety belt hook is closed, the lock bar is in a state of tension between the hook body and the stopper in the closed position, so that the safety belt hook can increase its rigidity in the front-rear direction. In addition, when the front of the locking side opening of the safety belt hook is opened, the lock bar moves to retreat toward the rear side of the locking side opening, so that the available aperture of the locking side opening can be secured large without being hindered by the lock bar. [Brief description of the drawings]

[0011] [Figure 1] FIG. 4 is a side view of the safety belt hook showing a state in which the engaging side opening is closed. [Diagram 2] FIG. 4 is a side view of the safety belt hook showing a state in which the engaging side opening is open. [Diagram 3] FIG. 2 is a reference diagram in which the grip and the opening / closing lever are omitted from FIG. [Figure 4] FIG. 3 is a reference diagram in which the grip and the opening / closing lever are omitted from FIG. 2. [Diagram 5] FIG. 2 is a perspective view of FIG. [Figure 6] FIG. 3 is a perspective view of FIG. 2. [Figure 7] FIG. 11 is an enlarged perspective view for reference showing a locking mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 and Fig. 2 are side views showing a safety belt hook 1 according to the present invention, Fig. 1 shows a state in which the front (right side in the figure) of the locking side opening 3 of the safety belt hook 1 is closed, and Fig. 2 shows a state in which the front of the locking side opening 3 of the safety belt hook 1 is open. Fig. 3 is a reference view in which the grip 10 and the opening / closing lever 5 are omitted from Fig. 1, Fig. 4 is a reference view in which the grip 10 and the opening / closing lever 5 are omitted from Fig. 2, Fig. 5 is a perspective view of Fig. 1, and Fig. 6 is a perspective view of Fig. 2. Fig. 7 is a reference enlarged perspective view showing the lock mechanism 7, where (A) shows the locked state and (B) shows the released state.

[0013] As shown in Figures 1 and 2, the safety belt hook 1 has a hook-shaped hook body 2 having an engaging side opening 3 on the front, a stopper 4 which directly opens and closes the engaging side opening 3, an opening / closing lever 5 which operates the opening and closing of the engaging side opening 3 in conjunction with the stopper 4, a lock bar 6 which is provided from the stopper 4 to the rear side of the hook body 2, and a lock mechanism 7 which controls the sliding of the lock bar 6. Here, the position where the stopper 4 closes the locking side opening 3 is referred to as a closing position, and the position where the stopper 4 opens the locking side opening 3 is referred to as an opening position.

[0014] As shown in FIG. 3, the hook body 2 is a hook-shaped member with a flat upper part having a locking side opening 3 at the front, and is a member that is directly locked to a fixing structure. The hook body 2 is provided with a lock mechanism 7 at the rear center. As shown in FIG. 4, the hook body 2 is provided with an approximately U-shaped engagement part 8 at the front end, which engages with a stopper 4 located at the closed position. The hook body 2 also has a connection hole 9 for attaching a lifeline or the like at the front of the lower part. The hook body 2 also has fixed shafts 11a, 11b, 11c, and 11d to which various members are attached. The hook body 2 has an opening / closing lever 5 attached to the fixed shaft 11c and a stopper 4 attached to the fixed shaft 11d. The hook body 2 is also provided with a grip 10, which is an approximately L-shaped member that a user holds in his / her hand when using the hook, attached integrally to the rear lower part of the hook body 2 so as to cover the hook body 2 from the rear. The grip 10 is fixed by the fixed shafts 11a, 11b, and 11c. Further, inside the grip 10, a slit (not shown) is formed through which the sliding lock bar 6 can retreat.

[0015] The stopper 4 is a generally dogleg-shaped member that can move between a blocking position where it stands upright to block the locking side opening 3 and an opening position where it falls backward to open the locking side opening 3. The stopper 4 is connected to the front of the lower part of the hook body 2 and rotatably about a fixed shaft 11d. A torsion spring (not shown) is provided on the fixed shaft 11d, and the stopper 4 is biased to the blocking position by the torsion spring. As shown in Figs. 5 and 6, the stopper 4 has an engaged part 16 that engages with the engaging part 8 of the hook body 2 at the front upper end in the blocking position. The stopper 4 is connected to the opening / closing lever 5 via a link member 17 that is rotatably attached to the fixed shaft 11e, and is interlocked with the operation of the opening / closing lever 5. The stopper 4 also has fixed shafts 11g and 11f to which the lock bar 6 is attached at the rear upper end.

[0016] The opening / closing lever 5 is a U-shaped member in a side view that is attached to the grip 10 so as to be rotatable about a fixed shaft 11c. The opening / closing lever 5 is connected to the stopper 4 via a link member 17 that is rotatably attached to the fixed shaft 11h. By rotating the opening / closing lever 5 backward, the stopper 4 is linked via the link member 17, and the stopper 4 is moved between the closed position and the open position.

[0017] The lock bar 6 is a rod-shaped member that is provided in the front-rear direction from the stopper 4 to the rear of the hook body 2 when the stopper 4 is in the closed position. The front end of the lock bar 6 in the closed position is fixed to the stopper 4 via fixed shafts 11f and 11g, and the lock bar 6 is interlocked with the operation of the stopper 4. The lock bar 6 is formed of two plate-shaped members so as to sandwich the lock member 20b described later and to be located between the lock members 20a described later. The tip portion 18 of the lock bar 6, which is the rear end in the closed position, has a notch 18a cut out at the bottom and a thin protrusion at the top. When the stopper 4 moves from the closed position to the open position, the lock bar 6 slides to retreat into the inside of the grip 10 in conjunction with the movement of the stopper 4. At this time, the lock bar 6 has a curved shape so that the sliding of the lock bar 6 is performed smoothly. The tip portion 18 is fixed by the lock mechanism 7, thereby restricting the sliding of the lock bar 6. By fixing the lock bar 6 in this manner, the lock bar 6 supports the stopper 4 in the closed position.

[0018] The lock mechanism 7 is a mechanism that can be switched between a locked state that restricts the sliding of the lock bar 6 and a released state that allows the sliding of the lock bar 6. As shown in FIG. 7, the lock mechanism 7 is composed of a lock member 20a provided with an unlock button 21 and a slide shaft 22, and a lock member 20b having a slide hole 23. The lock member 20a is a member that is attached to the fixed shaft 11a so that the unlock button 21 protrudes from the upper part of the grip 10 and the slide shaft 22 protrudes forward from the center of the grip 10. The lock member 20b is a member that is integrally provided to the hook body 2 and has an arc-shaped slide hole 23. The positions of the lock members 20a and 20b are determined so that the slide hole 23 supports the slide shaft 22 so that it can move in the front-rear direction. When no external force is applied to the unlock button 21, as shown in Fig. 7(A), the lock member 20a is fixed by a spring (not shown) so that the slide shaft 22 is pressed against the rear end of the slide hole 23. When the unlock button 21 is pressed in, the slide shaft 22 moves to the front of the slide hole 23 as shown in Fig. 7(B).

[0019] Here, a structure for controlling the sliding of the lock bar 6 by the lock mechanism 7 when the stopper 4 is in the closed position will be described. In the safety belt hook 1, the protruding portion of the tip 18 of the lock bar 6 is configured to be located behind the slide hole 23. When no external force is applied to the unlock button 21, that is, when the lock mechanism 7 is in the locked state, the shaft portion of the slide shaft 22 supports the notch 18a of the tip 18, thereby restricting the rearward sliding of the lock bar 6. When the lock bar 6 is fixed by the lock mechanism 7, it is in a tensioned state between the hook body 2 and the stopper 4 in the closed position.

[0020] When the unlock button 21 is pressed, the slide shaft 22 moves forward in the slide hole 23, releasing the fixation of the tip 18 by the slide shaft 22 and allowing the lock bar 6 to slide (lock mechanism 7 in the released state). When the unlock button 21 is no longer pressed after the lock mechanism 7 is set to the released state, the slide shaft 22 is again pressed against the rear end of the slide hole 23 by a spring (not shown), and the tip 18 of the lock bar 6 is fixed.

[0021] Next, the operating procedure of the safety belt hook 1 will be described below. Holding the grip 10 in one's hand, the lock release button 21 is pressed toward the hook body 2 to release the lock mechanism 7 and allow the lock bar 6 to slide. Next, while keeping the lock release button 21 pressed, the opening / closing lever 5 is operated so as to tilt toward the rear side of the hook body 2. When the opening / closing lever 5 is operated, the stopper 4 moves in conjunction with the operation of the link member 17 to the open position around the fixed shaft 11d. Furthermore, in conjunction with the operation of the stopper 4, the lock bar 6 slides to retreat inside the grip 10. In this manner, the locking side opening 3 is opened.

[0022] At this time, the stopper 4 moves toward the lower side of the hook body 2, and the lock bar 6 slides to retreat into the grip 10, so that a large diameter can be secured for the available opening 3 of the locking side. Moreover, since the stopper 4 has a U-shape that is concave toward the inside of the hook body 2, a larger diameter can be secured. In addition, since the fingers of the user (not shown) holding the opening / closing lever 5 are positioned in the gap V (FIG. 2) between the stopper 4 and the opening / closing lever 5, the stopper 4 can protect the fingers of the user when attaching or detaching the device to or from the fixing structure, and the fingers of the user do not get in the way when attaching or detaching the device to or from the fixing structure.

[0023] After the safety belt hook 1 has been attached to or detached from the fixing structure, the stopper 4 rotates forward and stands upright due to a torsion spring (not shown) attached to the rotating shaft 11d, engaging the engaged portion 16 with the engaging portion 8 of the hook body 2. Finally, by releasing the unlock button 21, the lock mechanism 7 enters the locked state and the lock bar 6 is fixed again. At this time, the safety belt hook 1 is supported by the lock bar 6 in the front-to-rear direction at the center, so that rigidity in the front-to-rear direction is maintained.

[0024] According to the above embodiment of the safety belt hook 1, the hook body 2 has a hook-shaped hook with a locking side opening 3, a stopper 4 that directly opens and closes the locking side opening 3, an opening / closing lever 5 that moves the stopper 4, and a lock bar 6 that extends backward from the upper end of the stopper 4 toward the hook body 2 when the stopper 4 is in the closed position. The lock bar 6 moves to retreat to the rear side of the locking side opening 3 when the stopper 4 moves from the closed position to the open position. Therefore, when the locking side opening 3 is closed, the safety belt hook 1 can increase the rigidity of the safety belt hook 1 in the front-rear direction by being in a state where the lock bar 6 is stretched between the hook body 2 and the stopper 4 in the closed position. In addition, when the front of the locking side opening 3 of the safety belt hook 1 is opened, the lock bar 6 moves to retreat to the rear side of the locking side opening 3, so that the available aperture of the locking side opening 3 can be secured large without being hindered by the lock bar 6.

[0025] The present invention has been described above based on the illustrated examples, and the technical scope of the present invention is not limited to these. For example, the material of each part constituting the safety belt hook can be freely selected from iron, aluminum, resin, etc., as long as it ensures the safety of the user.

[0026] Furthermore, the parts constituting the safety belt hook may be manufactured from a single material or from multiple materials. In addition, the shape of each part is not limited to that shown in the drawings as long as it can solve the problem of the present invention. For example, the non-linear stopper may be an arc or trapezoid other than the V-shape shown in the example. Furthermore, as long as the lock mechanism can control the sliding of the lock bar, the specific structure and the location where it is provided can be determined arbitrarily and are not limited to the structure of the embodiment. [Explanation of symbols]

[0027] 1··Safety belt hook, 2··Hook body, 3··Latching side opening, 4··Stopper, 5··Opening / closing lever, 6··Lock bar, 7··Lock mechanism, 8··Engaging portion, 9··Connection hole, 10··Grip, 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h··Fixed shaft, 16··Engaged portion, 17··Link member, 18··Tip portion, 20a, 20b··Lock member, 21··Lock release button, 22··Slide shaft, 23··Slide hole, V··Gap.

Claims

1. A hook body having a hook-side opening at the front; A safety belt hook is provided with a stopper connected to a lower end of the hook body and movable between a blocking position where the hook body stands upright to block the locking side opening and an opening position where the hook body falls backward to open the locking side opening, an opening / closing lever, the lower end of which is connected to the lower part of the hook body so as to be rotatable in the front-rear direction, at a position rearward of the stopper and inside the hook body; a lock bar extending rearward from an upper end of the stopper toward the hook body in the closed position; a lock mechanism that is provided on the hook body and that is switchable between a locked state in which the lock mechanism engages with a rear end of the lock bar to restrict rearward movement of the lock bar and a released state in which the lock mechanism does not engage with the rear end of the lock bar to allow rearward movement of the lock bar, the opening / closing lever is connected to the stopper so that the stopper moves in conjunction with the rotation of the opening / closing lever, When the stopper is moved from the closed position to the open position by the opening / closing lever in the released state of the locking mechanism, the lock bar moves together with the stopper so as to retreat to the rear side of the engagement side opening.

2. The safety belt hook according to claim 1, characterized in that, when the stopper moves from the closed position to the open position, the lock bar penetrates the hook body, slides within the hook body, and assumes a posture along the hook body at the closed position.

3. 3. The safety belt hook according to claim 1, wherein the opening / closing lever is connected to the stopper via a link member so that the stopper moves in conjunction with the rotation of the opening / closing lever.

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