Holding tool, holding method

Abstract

To suppress deviation of a holding tool against a held material.SOLUTION: A holding tool that holds a liner held material, comprises a first winding grip 10 and a second winding grip 20. The first winding grip 10 has: a pair of first leg parts 12 wound in a spiral shape to a held material 50; and a first curving part 11 alternately connecting base ends of the pair of first leg parts 12. The second winding grip 20 has: a pair of second leg parts 22 wound in the spiral shape from an upper side of each first leg part 12 to the held material 50 to which each first leg part 12 is wound; and a second curving part 21 alternately connecting both base ends of the pair of second leg parts 22. A winding direction of each first leg part 12 and a winding direction of each second leg part 22 are an inverse direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a gripping tool and a gripping method.

Background Art

[0002] As a gripping tool for gripping a linear object to be gripped such as an electric wire or a branch line, a winding grip is known (see Patent Document 1). By spirally winding a pair of legs around the linear object, the winding grip grips the object to be gripped.

[0003] When tension is applied to the object to be gripped, a torsional moment is generated in the legs. As a result, the legs may shift with respect to the object to be gripped, and the gap between the legs may increase. If the gap increases, there is a risk that the object to be gripped will jump out to the outside of the legs through the gap.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been completed based on the above circumstances, and an object thereof is to suppress the displacement of the legs with respect to the object to be gripped even when tension is applied to the object to be gripped by the gripping tool.

Means for Solving the Problems

[0006] A gripping device for gripping a linear object comprises a first wrap-around grip and a second wrap-around grip, wherein the first wrap-around grip has a pair of first legs that spirally wrap around the object to be gripped and a first curved portion that connects the base ends of the pair of first legs to each other, and the second wrap-around grip has a pair of second legs that spirally wrap around the object to be gripped with the first legs wrapped around it, from above the first legs and a second curved portion that connects the base ends of the pair of second legs to each other, and the winding direction of the first legs and the winding direction of the second legs are in opposite directions.

[0007] When tension is applied to the object being gripped by the gripping device, a torsional moment is generated in the first wrap-around grip wrapped around the object, in the opposite direction to the winding direction of the first leg. Simultaneously, a torsional moment is generated in the second wrap-around grip wrapped around the first leg, in the opposite direction to the winding direction of the second leg. Since the winding directions of the first and second legs are opposite, the torsional moments generated in the first wrap-around grip and the torsional moments generated in the second wrap-around grip cancel each other out. As a result, rotation of the first and second legs relative to the object being gripped is suppressed, and the displacement of the first and second legs relative to the object being gripped is suppressed. [Effects of the Invention]

[0008] According to the present invention, even when tension is applied to the linear object being gripped by the gripping device, the displacement of the legs (first leg and second leg) relative to the object being gripped can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] Plan view of the first wrap-around grip and the second wrap-around grip that constitute the gripping device. [Figure 2] Diagram (1) illustrating the procedure for grasping an object to be grasped. [Figure 3] Diagram (2) illustrating the procedure for grasping an object to be grasped. [Figure 4] Partial enlargement view of Figure 3(b) [Figure 5] Figure 2(b) Cross-sectional view AA [Figure 6] Figure 2(b) Cross-sectional view AA [Figure 7] Figure 3(b) BB cross-section [Modes for carrying out the invention]

[0010] <Embodiment> 1. Configuration of the gripping device 30 One embodiment of the gripping device 30 according to the present invention will be described with reference to Figures 1 to 7. The gripping device 30 is a gripping device for gripping a linear composite stranded wire (an example of the "object to be gripped") 50.

[0011] As shown in Figure 1, the gripping device 30 has a first winding grip 10 and a second winding grip 20. Figure 1 is a diagram showing the first winding grip 10 and the second winding grip 20 individually before they are wound onto the composite stranded wire 50.

[0012] The first wrap-around grip 10 is formed by twisting together multiple steel wires. The first wrap-around grip 10 has a pair of first legs 12 (12A, 12B) and a first curved section 11. The first curved section 11 connects the base ends of the pair of first legs 12 at the base end side (left side in the plane of Figure 1). The first curved section 11 is the part that is attached to, for example, a split wire or a ball insulator and fixed to another structure.

[0013] The pair of first legs 12 (12A, 12B) are each formed in a spiral shape. The diameter, winding direction, and pitch of the spirals of the first legs 12A and 12B are the same. The spiral shape of one first leg 12A and the spiral shape of the other first leg 12B are formed with a half-pitch offset with respect to the extension direction of the first leg 12 (left-right direction in Figure 1), so that they do not interfere with each other when wrapped around the object to be gripped 50, which will be described later.

[0014] The second wound grip 20 is formed by twisting a plurality of steel wires and has a second curved portion 21 and a pair of second leg portions 22 (22A, 22B). The first wound grip 10 and the second wound grip 20 have the same configuration except that the winding directions of the spirals of the first leg portion 12 and the second leg portion 22 are opposite.

[0015] In this embodiment, the winding direction of the first leg portion 12 is clockwise (an example of the "first winding direction") when viewed from the tip toward the base end. On the other hand, the winding direction of the second leg portion 22 is counterclockwise (an example of the "second winding direction"), which is opposite to that of the first leg portion 12. The winding directions of the first leg portion 12 and the second leg portion 22 are not limited to the above directions as long as they are opposite to each other. Also, as an example, the pitches of the spiral shapes of the first leg portion 12 and the second leg portion 22 are the same.

[0016] 2. Process description Next, referring to FIGS. 2(a)(b) and FIGS. 3(a)(b), the process of gripping the composite twisted wire 50 using the gripper 30 will be described.

[0017] First, the first leg portion 12 of the first wound grip 10 is wound around the composite twisted wire 50. FIG. 2(a) shows a state where the first leg portion 12 is wound around the composite twisted wire 50 halfway. The winding direction of the first leg portion 12 is clockwise when viewed from the tip of the first leg portion 12. FIG. 2(b) shows a state where the first leg portion 12 is wound around the composite twisted wire 50 up to the tip.

[0018] Next, the second leg portion 22 of the second wound grip 20 is wound around the composite twisted wire 50 with the first leg portion 12 wound thereon from the outside of the first leg portion 12. FIG. 3(a) shows a state where the second leg portion 22 is wound halfway. The winding direction of the second leg portion 22 is counterclockwise, which is opposite to that of the first leg portion 12, when viewed from the tip of the second leg portion 22. A state where the second leg portion 22 is wound around the composite twisted wire 50 up to the tip is shown in FIG. 3(b). Also, FIG. 4 is a partially enlarged view of FIG. 3(b).

[0019] 3. Effect description FIG. 2(b) is a diagram showing a state in which the composite twisted wire 50 is gripped by only one winding grip (the first winding grip 10). Conventionally, the object to be gripped (the composite twisted wire 50) was gripped by only one winding grip in this way.

[0020] The A-A cross section of FIG. 2(b) is shown in FIG. 5(a). In this state, the pair of first leg portions 12A and 12B are at positions 180° apart on the outer periphery of the composite twisted wire 50 and grip the composite twisted wire 50 from both sides. Among the outer periphery of the composite twisted wire 50, the portion not covered by the first leg portions 12A and 12B is the gap of the first leg portion 12, and the composite twisted wire 50 is exposed.

[0021] When tension is applied to the composite twisted wire 50, such as stretching the composite twisted wire 50 between transmission towers, a torsional moment M0 in the direction opposite to the winding direction of the helix (counterclockwise in FIG. 5(a)) is generated in the first leg portions 12A and 12B, and the first leg portions 12A and 12B slide on the outer periphery of the composite twisted wire 50 and displace counterclockwise. The amount of displacement may not be the same between the first leg portions 12A and 12B. In this case, the first leg portions 12A and 12B approach each other (see FIG. 5(b)). When the first leg portions 12A and 12B approach each other, a gap widens on the opposite side, and there is a possibility that the composite twisted wire 50 may pop out from the gap.

[0022] Also, as shown in FIG. 6, the composite twisted wire 50 has a multilayer structure composed of an outer layer 51, an inner layer 52, and a core material 53 in order from the outside, and the twisting direction of the strands is different for each layer. When tension is applied to the composite twisted wire 50, the composite twisted wire 50 rotates in one direction (counterclockwise in FIG. 6) due to the counterclockwise torsional moment M0 of the first leg portion 12. As a result, the strands constituting the outer layer 51 loosen and the tension they bear decreases, while the strands constituting the inner layer 52 tighten and the tension they bear increases. The tension shared by the strands becomes non-uniform for each layer, and there is a risk of deformation and damage to the strands.

[0023] In the configuration of this embodiment, as shown in Figures 1 to 3, the winding directions of the first leg portion 12 wound around the composite stranded wire 50 and the second leg portion 22 wound over the first leg portion 12 are opposite. In this case, as shown in Figure 7, the counterclockwise torsional moment M1 generated in the first leg portion 12 and the clockwise torsional moment M2 generated in the second leg portion 22 cancel each other out. When the torsional moments M1 and M2 cancel each other out and decrease, the displacement of the first leg portion 12 and the second leg portion 22 on the outer circumference of the composite stranded wire 50 is suppressed. As a result, the gaps in the first leg portion 12 and the second leg portion 22 are less likely to widen, and the composite stranded wire 50 is prevented from popping out of the gap in the gripping device 30.

[0024] When the winding grip is wrapped around a composite stranded wire 50 with a large outer diameter, the gaps in the first leg portion 12 and the second leg portion 22 before tension is applied are larger compared to the case with a small outer diameter. The gripping portion 30 of this embodiment is particularly effective in suppressing the sprawl of the composite stranded wire 50 when its outer diameter is large, because the gaps in the legs do not widen easily even when tension is applied.

[0025] Furthermore, since the generated torsional moments M1 and M2 cancel each other out, the rotation of the composite stranded wire 50 when tension is applied is suppressed. As a result, the tension distributed among the individual wires constituting each layer of the composite stranded wire 50 is less likely to be uneven, and deformation and damage to the individual wires are suppressed even when the tension is high.

[0026] <Other Embodiments> The present invention is not limited to the embodiments described above and in the drawings, and the following embodiments, for example, are also included in the technical scope of the present invention.

[0027] (1) Although the example given is that the object to be gripped is a composite stranded wire 50, the object to be gripped may be a single stranded wire or a linear object made of a single material without strands.

[0028] (2) In the above embodiment, the example was given in which the helical pitch of the first leg portion 12 and the second leg portion 22 are the same, but they may be different.

[0029] (3) In the above embodiment, the case in which tension is applied to the composite stranded wire 50 was illustrated, but the same effect as in the above embodiment can be obtained even if the tension fluctuates after the tension is applied.

[0030] (4) In the above embodiment, the example shown is that the composite stranded wire 50 has a two-layer structure consisting of an outer layer 51 and an inner layer 52, excluding the core material 53, but it may also have a multilayer structure of three or more layers. [Explanation of Symbols]

[0031] 10. Grip included with Volume 1 11. First curved section 12(12A, 12B) 1st leg 20. Grip attached to Volume 2. 21 Second Curve Section 22(22A, 22B) 2nd leg 30 Gripping tool 50. Compound stranded wire (an example of "object to be held") 51 strands 52 Core material

Claims

1. A gripping device for gripping a linear object, It is equipped with a first wrap-around grip and a second wrap-around grip, The aforementioned first wrap-around grip is A pair of first legs that spirally wrap around the object to be grasped, It has a first curved portion that connects the base ends of a pair of first legs to each other, The aforementioned second wrap-around grip is A pair of second legs that spirally wrap around the object to be gripped, with the first leg wrapped around it, It has a second curved portion that connects the base ends of a pair of the second legs to each other, A gripping device in which the winding direction of the first leg and the winding direction of the second leg are in opposite directions.

2. The steps include: wrapping a pair of first legs of the first wrapping grip spirally around a linear object to be gripped in the first winding direction; A gripping method comprising the step of spirally wrapping a pair of second legs of a second wrapping grip around the object to be gripped, which has the first legs wrapped around it, from above the first legs in a second wrapping direction opposite to the first wrapping direction.

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