Safety belt attaching tool

Abstract

To provide a safety belt attaching tool that can be engaged with a longitudinal member of a scaffold by a simple operation, and can secure large engagement strength capable of preventing transverse sliding and downward sliding accompanying the transverse sliding in the state that attachment to the longitudinal member is completed.SOLUTION: A safety belt attaching tool includes: an attaching part 12 attached detachably to a longitudinal member of a scaffold component and hook engagement plates 14a and 14b with which a hook of a safety belt can be engaged. The attaching part includes a pair of engagement pieces 16a and 16b formed in an arc shape, and the opposing engagement pieces are pivotally attached at one end of the arc shape, and the other end is configured to be openable and closable. The hook engagement plates protrude from the other ends of the two engagement pieces, and the hook engagement plate is provided with a latch mechanism 38 for regulating opening and closing between the other ends of the two engagement pieces, and fastening means 52 for fastening the other ends of the two engagement pieces.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a safety belt fastener for attaching a safety belt hook to a vertical member of scaffolding set up at a construction site or the like. [Background technology]

[0002] At construction sites, it is common to set up scaffolding made of materials such as single-tube pipes on the outside of exterior walls. On scaffolding equipped with handrails, workers can work safely by hooking the hook attached to the end of the rope of their safety harness onto the handrail. On the other hand, to work on a scaffolding that does not have handrails installed, the hook is hooked onto an overhead horizontal member or a vertical member on that level. When the hook is attached to an overhead cross member, it is attached at a higher position than normal, so there is no leeway in the length of the safety belt rope, which significantly limits the worker's range of movement, i.e., the worker's range of work.

[0003] When a hook is attached to a vertical member, unless there is a protrusion that crosses the vertical member, the hook will fall to the intersection with the horizontal member below. If the hook falls to the horizontal member at the foot of that story, the fall distance in the event of a fall will be long, which is extremely dangerous. Furthermore, even if the horizontal member intersects the middle part of the vertical member and the hook can be engaged at that intersection, the engaged hook will be in a horizontal position, so in the event of a fall, a lateral bending load will be applied to the hook's hook, which may break and come off.

[0004] In order to eliminate the problems that arise when hooks are directly engaged with the horizontal and vertical members as described above, clamps such as those shown in Figs. 17 and 18 are currently used (for example, Patent Document 1). 17, a clamp 110 has a pair of engaging pieces 111, 112 that can be fitted onto the vertical member 102 and are pivotally attached so as to be able to open and close freely, a bolt 113 with a nut 115 threadedly engaged therewith is connected to the end of one of the engaging pieces 111, and a recessed groove 114 is formed in the end of the other engaging piece 112. In addition, an annular portion 116 is provided on the engaging piece 111. The clamp 110 can be attached to any location on the vertical member 102 by sandwiching the vertical member 102 between the engaging pieces 111 and 112, fitting the bolt 113 into the recessed groove 114, and tightening the ends of the engaging pieces 111 and 112 with a nut 115. The occurrence of the above-mentioned problems is prevented by engaging the hook 104 with the annular portion 116.

[0005] 18, a mounting portion 121 includes a pair of substantially semicircular frames 122, 123 arranged facing each other, with one end 124, 125 pivotally mounted and the other end 126, 127 openable and closable. Hook-hanging plywood plates 130, 131, each having annular portions 128, 129, protrude vertically from the other end 126, 127. A latch mechanism 132 is rotatably connected to the hook-hanging plywood 131. Pressing portions 133, 134 are provided on the undersides of the frames 122, 123 near the other end 126, 127. The installation is completed by placing the vertical members inside both frames 122, 123 and closing them, locking the mounting portion 121 with the latch mechanism 132, and tightening both frames 122, 123. The occurrence of the above-mentioned problems is prevented by engaging the hooks with the annular portions 128, 129. In the unlikely event that the worker falls, a downward load acting on the annular portions 128, 129 will cause a moment to act on the clamp 120, causing the clamp 120 itself to tilt. As a result, the pressing portions 133, 134 provided on the undersides of the frames 122, 123 will bite into the outer peripheral surfaces of the vertical members, preventing the clamp 120 from sliding downward. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-310040 Summary of the Invention [Problem to be solved by the invention]

[0007] If the direction of the annular portion 116 of the clamp 110 described above when attached to the vertical member 102 is set to the front (0 degrees), the worker may often perform work at positions that are more than 45 degrees to the left or right from the front. In other words, this occurs when the clamp 110 is used in a work range that is nearly sideways relative to the annular portion 116. If a worker were to fall from such a work position, the clamp 110 would be subjected to a large load not only in the downward direction but also in the lateral direction. If a lateral load greater than the static friction force generated between the clamp 110 and the vertical member 102 is applied to the clamp 110, the clamp 110 would begin to move around the vertical member 102 as its axis. Since the friction force after the clamp 110 starts to move becomes a kinetic friction force with a kinetic friction coefficient smaller than the static friction coefficient, the clamp 110, to which a lateral load greater than the kinetic friction force is applied, would continue to rotate around the vertical member 102. In other words, the clamp 110 would slide sideways. In such a case, it was found that not only would the clamp 110 slide sideways due to a lateral load greater than the kinetic friction force, but it would also slide downward due to a downward load greater than the kinetic friction force, and the clamp 110 would slide down while rotating around the vertical member 102 as its axis.

[0008] Furthermore, when installing a clamp using bolts and nuts for fastening, as shown in Figure 17, it is necessary to use one hand to support the clamp so that the installation height does not shift, while using the other hand to perform the fastening work. In this way, both hands must be used at all times until installation is complete, which makes the work less convenient. Furthermore, the clamp shown in Figure 18 uses a method of clamping and tightening the mounting frame, so there is a risk that the engagement strength may be loosened when tightened depending on the individual differences in the vertical member. In this case, there is a higher risk of the vertical member sliding down while rotating around the axis due to lateral and downward loads during a fall, so measures to address this were necessary.

[0009] An object of the present invention is to provide a safety belt attachment device that can be easily engaged with a vertical member of a scaffold and that, once attached to the vertical member, can ensure a large engagement strength that can prevent lateral slippage and the resulting downward slippage. [Means for solving the problem]

[0010] The safety belt mounting device of the present invention comprises an attachment part that can be detachably attached to a vertical member of a scaffolding component, and a hook attachment plate onto which the hook of a safety belt can be attached, the attachment part having a pair of arc-shaped engaging pieces, the opposing engaging pieces being pivotally attached at one end of the arc-shaped engaging pieces and the other end being configured to be able to open and close freely, the hook attachment plate protruding from the other end of the both engaging pieces, and the hook attachment plate is provided with a latch mechanism that regulates the opening and closing between the other ends of the both engaging pieces, and a fastening means that tightens the other ends of the both engaging pieces.

[0011] In the safety belt mounting device of the present invention, it is preferable that the fastening means is connected to the latch mechanism, and the latch mechanism is in a lock position that restricts the other ends of both engagement pieces to a closed state, and when the fastening means is in a tightened position, the latch mechanism is in a locked state, and when the fastening means is not in a tightened position, the latch mechanism is in an unlockable state. In the safety belt mounting device of the present invention, it is preferable that the mounting part is provided with pressing parts, one pair of pressing parts on the upper surface side of the engaging piece and another pair on the lower surface side, each of the upper surface pressing parts being disposed near one end of each of the engaging pieces, and each of the lower surface pressing parts being disposed near the other end of each of the engaging pieces. In the safety belt attaching device of the present invention, it is preferable that a biasing member is provided on the fastening means, and the biasing force of the biasing member biases the fastening means in a direction that moves outward from the opposing surface of the hook-hanging plywood. [Effects of the Invention]

[0012] The safety belt attachment device of the present invention can be easily engaged with a vertical member using the latch mechanism. Then, attachment is completed by tightly tightening the other ends of both engagement pieces with the fastening means. In this way, once attachment to the vertical member is complete, an engagement strength sufficient to withstand a large load is ensured. Therefore, even if a large lateral load is applied to the safety belt attachment device due to a fall while using the safety belt attachment device in a nearly horizontal working range, lateral slippage of the safety belt attachment device can be prevented. The resulting downward slippage can also be prevented. Furthermore, since the attachment portion is tightened by the fastening means, it can be securely and reliably fastened even to vertical members whose engagement strength is weak when tightened with the latch mechanism. Furthermore, the latch mechanism has enough strength to prevent the safety belt attachment device from shifting in height under the load generated during normal work. This means that the subsequent fastening means can be used to fasten the safety belt attachment device without having to support it with one hand. This eliminates the need to use both hands during the fastening process, making it easier to use. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a front view showing the safety belt attachment device of the present embodiment. [Figure 2] FIG. 2 is a rear view of FIG. [Figure 3] FIG. 2 is a right side view of FIG. [Figure 4] FIG. 2 is a left side view of FIG. 1. [Figure 5] FIG. 2 is a plan view of FIG. [Figure 6] FIG. 2 is a bottom view of FIG. 1. [Figure 7] FIG. 10 is a diagram illustrating a first engagement piece. [Figure 8] FIG. 10 is a diagram illustrating a second engagement piece. [Figure 9] FIG. 10 is a diagram illustrating the first hook-hanging plywood. [Figure 10] FIG. 10 is a diagram illustrating the second hook-hanging plywood. [Figure 11] FIG. [Figure 12]FIG. [Figure 13] FIG. [Figure 14] FIG. 10 is a diagram showing a state in which the mounting portion is opened. [Figure 15] FIG. 10 is a view showing a state in which the latch mechanism is rotated. [Figure 16] FIG. 10 is a diagram showing the state of attachment to the vertical member. [Figure 17] FIG. 1 illustrates a conventional clamp. [Figure 18] FIG. 10 is a diagram showing another type of conventional clamp. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a front view showing a safety belt attachment device of this embodiment. Fig. 2 is a rear view of Fig. 1. Fig. 3 is a right side view of Fig. 1. Fig. 4 is a left side view of Fig. 1. Fig. 5 is a plan view of Fig. 1. Fig. 6 is a bottom view of Fig. 1. As shown in FIGS. 1 to 6, the safety belt attachment device 10 of this embodiment includes an attachment part 12 and hook-hanging plywood plates 14a and 14b.

[0015] <Mounting section configuration> The attachment portion 12 is a member for detachably attaching the safety belt attachment device 10 to a vertical member of a scaffolding component. The mounting portion 12 has a pair of opposing arc-shaped first and second engagement pieces 16a and 16b. FIG. 7 is a diagram illustrating the first engagement piece 16a. As shown in FIG. 7, the first engagement piece 16a is composed of a first shaft portion 18a, a first arc portion 20a, and a first fastening portion 22a. The first shaft portion 18a is provided at one end of the first arc portion 20a, and the first fastening portion 22a is provided at the other end. The first shaft portion 18a has an axial hole 24a for connecting to the second engagement piece 16b. A first hook engaging plate 14a projects perpendicularly from the first fastening portion 22a on the other end side of the first arc portion 20a of the first engagement piece 16a. Figure 8 is a diagram illustrating the second engagement piece 16b. As shown in Figure 8, the second engagement piece 16b is composed of a second shaft portion 18b, a second arc portion 20b, and a second fastening portion 22b. The second shaft portion 18b is provided at one end of the second arc portion 20b, and the second fastening portion 22b is provided at the other end. The second shaft portion 18b has a shaft hole 24b for connecting to the first engagement piece 16a. A second hook-holding plate 14b projects perpendicularly from the second fastening portion 22b on the other end side of the second arc portion 20b of the second engagement piece 16b.

[0016] The first engaging piece 16a and the second engaging piece 16b are arranged facing each other and are connected by overlapping the first shaft portion 18a and the second shaft portion 18b and inserting a shaft 26 into the communicating shaft holes 24a, 24b. With this connection, the opposing engaging pieces 16a, 16b are axially attached to one end of the arcuate portions 20a, 20b, and the other end can be freely opened and closed. By closing the space between the two fastening portions 22a, 22b on the other end side, the two arcuate portions 20a, 20b form a circular pipe internal space 28. This internal space 28 serves as a holding space for the vertical member.

[0017] <Configuration of hook-hanging plywood> The safety belt fastener 10 of this embodiment is used by engaging the hooks of the safety belt with the loop portions 30a, 30b formed on the hook-hanging plywood plates 14a, 14b. The annular portions 30a, 30b are formed by forming through holes in the first hook plywood 14a and the second hook plywood 14b. The annular portions 30a, 30b are formed to have the same shape. The hook plywoods 14a, 14b protrude perpendicularly from the fastening portions 22a, 22b located on the other end sides of the engaging pieces 16a, 16b. The hook plywoods 14a, 14b are arranged to overlap when the fastening portions 22a, 22b on the other end sides of the engaging pieces 16a, 16b are closed. The annular portions 30a, 30b are positioned so that they communicate at the same position when the hook plywoods 14a, 14b are overlapped. Figure 9 is a diagram illustrating the first hook hanging plate 14a. As shown in Figure 9, the first hook hanging plate 14a is provided with a through groove 32 through which a fastening means (described later) passes, and a shaft hole 34 for connecting a latch mechanism (described later). Figure 10 is a diagram illustrating the second hook hanging plate 14b. As shown in Figure 10, the second hook hanging plate 14b is provided with a screw hole 36. A screw thread is formed on the inner surface of this screw hole 36.

[0018] <Latch mechanism configuration> The safety belt attachment device 10 of this embodiment is provided with a latch mechanism 38. This latch mechanism 38 regulates the opening and closing between the fastening portions 22a, 22b on the other end sides of the engaging pieces 16a, 16b. FIG. 11 is a plan view of the latch mechanism, and FIG. 12 is a rear view of the latch mechanism. As shown in FIG. 11, the latch mechanism 38 comprises a locking piece 40 having a U-shaped cross section. As shown in FIG. 12, a connection surface 42 of the locking piece 40 that connects with the first hook engagement plate 14a is formed in substantially the same shape as the first hook engagement plate 14a. A through hole is formed in the connection surface 42, thereby providing an annular portion 44 having the same shape as the annular portions 30a, 30b of both hook engagement plates 14a, 14b. This annular portion 44 is positioned so that it is in the same position as and communicates with the annular portions 30a, 30b when the latch mechanism 38 is in the locked position that restricts the other ends of both engagement pieces 16a, 16b to a closed state.

[0019] The connecting surface 42 is provided with a shaft hole 46 for connecting the latch mechanism 38 to the first hook engaging plate 14a and a mounting hole 48 for attaching a fastening means (described later). The mounting hole 48 is positioned so that its center coincides with the screw hole 36 of the second hook engaging plate 14b when the latch mechanism 38 is in the locked position. The latch mechanism 38 is connected to the first hook hanging plate 14a by overlapping the first hook hanging plate 14a and the connecting surface 42 of the lock piece 40 and inserting a shaft 50 into the communicating shaft holes 34, 46. This connection allows the latch mechanism 38 to be rotatably connected to the first hook hanging plate 14a. By closing the fastening portions 22a, 22b at the other ends of the engaging pieces 16a, 16b, the overlapping hook-hanging plywoods 14a, 14b are clamped and tightened by the locking piece 40, thereby restricting opening and closing between the fastening portions 22a, 22b.

[0020] <Configuration of fastening means> The safety belt fastening device 10 of this embodiment is provided with fastening means 52. This fastening means 52 can tighten the space between the fastening portions 22a, 22b on the other end sides of the engaging pieces 16a, 16b. FIG. 13 is a plan view of the fastening means. As shown in FIG. 13, the fastening means 52 includes a knob portion 54, a small-diameter portion 56, and a threaded portion 58, in this order, and the knob portion 54, small-diameter portion 56, and threaded portion 58 are arranged on the same axis. The knob portion 54 has a diameter larger than the inner diameter of the mounting hole 48 provided in the connecting surface 42 of the lock piece 40, and is shaped to be easy for an operator to grasp and turn. The small-diameter portion 56 is formed with a diameter smaller than the inner diameter of the mounting hole 48. The threaded portion 58 has a diameter larger than the inner diameter of the mounting hole 48, an outer diameter corresponding to the inner diameter of the threaded hole 36 provided in the second hook-hanging plyplate 14b, and a thread having the same pitch as the threaded hole 36.

[0021] The fastening means 52 is connected to the latch mechanism 38. Specifically, the small-diameter portion 56 is inserted into the mounting hole 48, and the fastening means 52 is attached so that the connection surface 42 is sandwiched between the knob portion 54 and the threaded portion 58. This allows the fastening means 52 to be rotatably connected. The fastening means 52 is arranged so that the threaded portion 58 faces the threaded hole 36 of the second hook-hanging plywood 14b, and the knob portion 54 faces outward. When the latch mechanism 38 is in the locked position, the axial center of the fastening means 52 is positioned to coincide with the center of the threaded hole 36. The latch mechanism 38 is rotated to the locked position to align the screw portion 58 with the screw hole 36, and the knob portion 54 is gripped and turned to engage the screw portion 58 with the screw hole 36, thereby tightening the fastening portions 22a, 22b of the engagement pieces 16a, 16b. When the fastening means 52 is in the tightened position, the latch mechanism 38 connected to the fastening means 52 cannot rotate, and therefore remains locked. On the other hand, when the fastening means 52 is not in the tightened position, the latch mechanism 38 can rotate, and therefore enters an unlockable state. In this way, the engagement by the fastening means 52 restricts the rotation of the latch mechanism 38.

[0022] The fastening means 52 may be provided with a spring (not shown) as a biasing member, and the biasing force of the spring may bias the fastening means 52 in a direction moving outward from the opposing surface of the second hook-hanging ply plate 14b. In this case, it is preferable that the spring is passed through the small diameter portion 56 and is arranged so as to bias the fastening means 52 between the connecting surface 42 and the knob portion 54. When the screw portion 58 is not fitted into the screw hole 36, the spring biases the tip of the screw portion 58 of the fastening means 52 so that it is kept at a position at least away from the screw hole 36 of the second hook-receiving plate 14b. This allows the latch mechanism 38 to rotate smoothly.

[0023] <Configuration of the pressing part> In the safety belt attachment device 10 of this embodiment, pressing portions 60, 62 are provided on the attachment portion 12. There is a pair of pressing portions on the upper surface side of the engagement pieces 16a, 16b and a pair on the lower surface side. The upper surface pressing portion 60 is disposed on the upper surface side near one end of both engagement pieces 16a, 16b. The lower surface pressing portion 62 is disposed on the lower surface side near the other end of both engagement pieces 16a, 16b. In the unlikely event that the worker falls, a downward impact force is generated at the annular portions 30a, 30b via the safety belt, causing a moment to act on the safety belt fastening device 10, causing the safety belt fastening device 10 itself to tilt. As a result, the outer circumferential surface of the vertical member 64 is pressed at four points: the upper surface pressing portions 60, 60 on one end of the engaging pieces and the lower surface pressing portions 62, 62 on the other end. In addition to the lower pressing portion 62 on the other end, a pressing portion 60 facing upward is provided at one end, opposite the vertical member, so that the moment acting on the safety belt mounting device 10 in the event of a fall increases, causing the lower pressing portion 62 to bite more strongly into the outer circumferential surface of the vertical member. This stronger bite into the vertical member by the pressing portions 60, 62 is also highly effective in preventing slippage in the lateral direction.

[0024] <How to use the safety belt attachment device> As shown in Figure 14, the safety belt attachment device 10 of this embodiment opens the engaging pieces 16a, 16b of the attachment part 12, fits the vertical member 64 into the pipe holding space 28, closes it, and then rotates the latch mechanism 38 in the direction of the arrow in Figure 15 to lock the attachment part 12. Thereafter, by tightening the fastening parts 22a, 22b with the fastening means 52, attachment to the vertical member 64 is completed as shown in Figure 16. The safety belt attachment device 10 attached to the vertical member 64 as described above is used by engaging the hooks of the safety belt with the loop parts 30a, 30b of the hook-hanging plywood plates 14a, 14b. The hook of the safety belt engages not only with the annular portions 30a, 30b of the hook-hanging plywood 14a, 14b but also with the annular portion 44 of the latch mechanism 38, so that even if the fastening means 52 comes out of engagement, the latch mechanism 38 cannot be rotated and is held in the locked position.

[0025] <Effects of this embodiment> According to this embodiment, the following effects can be obtained. The safety belt attachment device 10 according to the present invention can be attached to the vertical member 64 by a simple operation of clamping and tightening the hook-hanging plywood plates 14a, 14b with the latch mechanism 38. Then, attachment is completed by using the fastening means 52 to tighten the fastening portions 22a, 22b of the engaging pieces 16a, 16b tighter than the engagement strength provided by the latch mechanism 38. Thus, since an engagement strength capable of withstanding a large load is ensured when attachment to the vertical member 64 is complete, lateral slippage of the safety belt attachment device 10 can be prevented even in the event of a fall and a large lateral load being applied. Consequently, downward slippage due to such a load can also be prevented. Furthermore, since the attachment portion 12 is tightened by the fastening means 52, it can be securely and reliably fastened even to vertical members whose engagement strength when tightened by the latch mechanism 38 is weak. Furthermore, the engagement by the latch mechanism 38 is strong enough that the load generated during normal work will not cause displacement of the mounting height. Therefore, the subsequent fastening means 52 can be used to fasten the safety belt mounting device 10 without having to support it with the hands. In this way, there is no need to always use both hands during the mounting work, resulting in excellent operability.

[0026] <Modification> The present invention is not limited to the above-described embodiments, and any modifications and improvements that can achieve the object of the present invention are included in the present invention. In the above embodiment, the fastening portions 22a, 22b are fastened together by fitting the threaded portion 58 of the fastening means 52 into the screw hole 36, but the present invention is not limited to this. For example, the fastening may be performed by fitting a bolt into a recessed groove and screwing a nut into the recessed groove. [Industrial Applicability]

[0027] The safety belt attachment device described above is suitable for use when working on scaffolding that does not have handrails. [Explanation of symbols]

[0028] 10 Safety belt attachment 12 Mounting part 14a, 14b First hook-hanging plywood, second hook-hanging plywood 16a, 16b First engagement piece, second engagement piece 30a, 30b Annular portion 38 Latch mechanism 52 Fastening means 60,62 Pressing part 64 Vertical members

Claims

1. The scaffolding system is provided with a mounting portion that can be detachably attached to the vertical member of the scaffolding component, and a hook-hanging plywood on which the hook of the safety belt can be hung, The mounting portion has a pair of arc-shaped engaging pieces, and the opposing engaging pieces are pivotally attached at one end of the arc-shaped engaging piece and configured so that the other end can be opened and closed freely. The hook-hanging plywood is provided to protrude from the other end of each of the engaging pieces, The hook-hanging plywood is provided with a latch mechanism that restricts the opening and closing of the other ends of the two engaging pieces, and a fastening means that fastens the other ends of the two engaging pieces. A safety belt attachment device characterized by:

2. the fastening means is connected to the latch mechanism; The latch mechanism is in a locked position where it restricts the other ends of both engagement pieces to a closed state, and when the fastening means is in a fastened position, the latch mechanism is in a locked state, and when the fastening means is not in a fastened position, the latch mechanism is in an unlockable state.

2. The safety belt attachment device of claim 1.

3. The mounting portion is provided with a pressing portion, The pressing portion has a pair on the upper surface side of the engaging piece and a pair on the lower surface side thereof, The upper surface pressing portions are disposed near one ends of the engagement pieces, The lower surface pressing portions are disposed near the other ends of the engaging pieces. A safety belt attachment device according to claim 1 or 2.

4. The fastening means is provided with a biasing member, and the biasing force of the biasing member biases the fastening means in a direction in which it moves outward from the opposing surface of the hook-hanging plywood. A safety belt attachment device according to claim 1 or 2.

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