JP5979676B2 - Earthing hardware and equipment - Google Patents

Description

  The present invention relates to a grounding fitting used for a grounding tool for grounding in the case of an overhead power transmission line stop work, and a grounding tool provided with the grounding fitting.

  An overhead power transmission line normally transmits power through a plurality of lines. When carrying out the construction and maintenance work of this overhead power transmission line, power transmission on the working line is stopped to prevent an electric shock accident of the worker. At that time, power is transmitted as usual in the line where the work is not performed, and an induced current flows through the line where the work is performed along with the power transmission. Therefore, before the work, it is necessary to ground the work line to a steel tower or the like to release the current and ensure the safety of the worker.

  Specifically, the grounding is performed by connecting an earth wire to the overhead power transmission line itself or a grounded metal fitting attached to the electric wire. A tool used for this grounding work is a grounding tool. As a grounding tool, the thing as described in patent document 1 is mentioned, for example.

  FIG. 5 is a schematic configuration diagram of a hook-type grounding tool as shown in FIG. The grounding tool 100 includes a telescopic insulating rod 101, a gripping fitting 102 provided at the tip of the insulating stick 101, and a grounding fixture 104 connected to the gripping fitting 102 via a ground wire 103. . The grounding tool 100 is attached by first connecting the ground metal fitting 104 to a grounding pole side member such as a metal armature of a steel tower, and then extending the insulating rod 101 and using the holding metal fitting 102 to conduct a conductive member such as an electric wire or a grounded metal fitting. This is done by gripping 200. By this operation, current can be released from the conductive member 200 to the grounding electrode side member via the gripping metal fitting 102, the ground wire 103, and the earthing metal fitting 104. As a result, even if an induced current flows through the line being worked on, an accident in which the worker is electrocuted is prevented. On the other hand, the grounding tool 100 is removed by first releasing the gripping of the conductive member 200 by the gripping bracket 102 to shorten the insulating rod 101 and then removing the grounding bracket 104 from the grounding pole side member.

JP 2000-278830 A

  Improvements are always being considered for grounding tools to increase their safety. For example, if the grounding metal member is detached from the ground electrode side member, current cannot be released to the ground electrode side member, which may cause an electric shock accident. For this reason, there is a need to reliably prevent the ground metal fitting attached to the grounding electrode side member from loosening once.

  As shown in FIG. 5, the ground metal fitting 104 includes a substantially C-shaped metal fitting body 104 a, a screw shaft 104 b that passes through an upper piece of the metal fitting main body 104 a (disposed on the lower side in FIG. 5), A pressing piece 104c loosely fitted on the tip of the screw shaft 104b and a handle 104d for rotating the screw shaft 104b are provided, and the grounding pole side member is tightened between the pressing piece 104c and the lower piece of the metal fitting body 104a. It is attached to the ground electrode side member. Because of this configuration, if an accidental external force acts on the handle 104d, the handle 104d and the screw shaft 104b connected to the handle 104d rotate when the grounding pole side member is not sufficiently tightened, and the grounding metal 104 There is a risk of loosening the mounting state. As an accidental external force, an external force generated when the ground wire 103 extending from the ground metal fitting 104 to the gripping metal is shaken by the wind and touches the handle 104d, or an object blown by the wind collides with the handle 104d. The external force generated by can be mentioned.

  The present invention has been made in view of the above circumstances, and a grounding metal that can greatly reduce the accidental loosening of the mounting state of the grounding metal attached to the grounding electrode side member, and a grounding tool using the grounding metal Is to provide.

  The grounding metal fitting of the present invention is a grounding metal fitting used for a grounding tool for holding a conductive member with a holding metal fitting provided at the tip of an insulating rod and releasing the current flowing through the conductive member to the grounding pole side member.・ Equipped with a pressing piece and handle. The metal fitting body is a member having an upper piece and a lower piece facing each other and side pieces connecting the upper piece and the lower piece, and to which a ground wire extending from the holding fitting is connected. The screw shaft is a member that passes through the upper piece of the metal fitting body and is screwed to the upper piece so as to be able to advance and retreat. The pressing piece is a member that is loosely fitted to the lower end of the metal fitting body of the screw shaft and sandwiches the ground electrode side member with the lower piece. The handle is a member that is provided above the upper piece of the metal fitting body of the screw shaft and is rotated around the axial direction of the screw shaft when the operator rotates the screw shaft. In the ground metal fitting of the present invention having these configurations, the handle is configured to be movable within a predetermined range in the axial direction of the screw shaft. The grounding metal fitting according to the present invention includes a non-transmission state in which the handle is idle with respect to the screw shaft depending on the position of the handle on the screw shaft (a state in which the rotation of the handle is not transmitted to the screw shaft), A switching mechanism for switching between a transmission state for rotation (a state in which the rotation of the handle is transmitted to the screw shaft) is provided. In this specification, the upper and lower sides of each member are defined with the handle side of the screw shaft as the upper side and the pressing piece side as the lower side.

  According to the grounding metal fitting of the present invention including the switching mechanism, it is possible to switch between the non-transmission state and the transmission state as necessary. Specifically, when attaching a grounding bracket to a grounding pole-side member such as a steel tower for construction or maintenance work, make sure that the screw shaft is in rotation for the rotation of the handle, rotate the handle, and attach it to the tip of the screw shaft. The grounding electrode side member is tightened between a certain pressing piece and the lower piece of the grounding metal fitting. After the grounding bracket is attached to the grounding pole side member, the handle is in a non-transmitting state in which the handle rotates idly with respect to the screw shaft, and the screw shaft does not rotate even if the handle rotates due to an accidental external force acting on the handle. To. By doing so, it is possible to greatly reduce the possibility that the earth metal fitting will come off from the grounding electrode side member during construction / maintenance work. It should be noted that when the grounding metal member is removed from the grounding pole side member at the end of the construction / maintenance work, the transmission state may be set again.

  As a grounding metal fitting of the present invention, a mode in which the switching mechanism of the grounding metal fitting includes an overhang portion, a cylindrical portion, a spring for switching mechanism, and a stopper portion can be mentioned. Here, the projecting portion is a member that is integrated with the screw shaft and projects outward in the radial direction of the screw shaft. The cylindrical portion is a member that is integrated with the handle and has a switching recess along the outer shape of the overhang portion integrated with the screw shaft. The switching mechanism spring is a member that is disposed between the overhang portion and the tubular portion and biases the handle including the tubular portion in a direction away from the overhang portion. The stop portion is a member that is provided on the screw shaft and defines an upper limit value of the separation distance between the handle and the overhang portion. In the switching mechanism having the above-described configuration, the extension portion and the switching recess of the cylindrical portion are fitted to each other so that the screw shaft is transmitted to the rotation of the handle, and the tension is applied by the urging force of the switching mechanism spring. By separating the protruding portion and the switching concave portion, the handle is in a non-transmitting state in which the handle idles with respect to the screw shaft.

  According to the above configuration, since the ground metal fitting is normally in a non-transmitting state by the action of the switching mechanism spring, it is possible to prevent the earth metal fitting attached to the ground electrode side member from being detached. On the other hand, when rotating the screw shaft at the time of attaching / removing the ground metal fitting, the handle including the cylindrical portion is moved to the projecting portion side with a force that overcomes the biasing force of the spring for the switching mechanism, and the switching concave portion of the cylindrical portion and The handle is rotated while maintaining the state (transmission state) in which the projecting portion of the screw shaft is fitted. If a transmission state maintaining mechanism to be described later is not provided, when the hand is released from the handle, the grounding metal is automatically brought into a non-transmission state by the action of the switching mechanism spring.

  As a grounding metal fitting of the present invention, a form provided with a transmission state maintenance mechanism which maintains the state where the overhanging part and the switching concave part are fitted can be mentioned.

  According to the said structure, when attaching a grounding metal fitting to a grounding pole side member, the operation | work which rotates a screw shaft with a handle can be made easy. This is because there is no need to continuously apply a force to overcome the urging force of the switching mechanism spring while the screw shaft is rotated.

  As the grounding metal fitting of the present invention having the transmission state maintaining mechanism, the transmission state maintaining mechanism is provided at the position of the ball plunger provided in the overhanging portion and the switching recess in the cylindrical portion, and the ball plunger is maintained in the ball. And a recess.

  According to the transmission state maintaining mechanism using the ball plunger, it is possible to maintain the transmission state relatively firmly and to easily switch from the transmission state to the non-transmission state.

As an earth metal fitting of the present invention, a form provided with a tightening state confirmation mechanism for visually confirming the tightening state of the grounding electrode side member by the pressing piece and the lower piece can be mentioned. In this case, the tightening state confirmation mechanism is interposed between the fixed piece fixed below the upper piece of the metal fitting body on the screw shaft and above the pressed piece, and between the pressed piece and the fixed piece. a spring for checking mechanism for urging the strips on the lower side of the screw shaft, may be configured to include a.

  According to the said structure, a clearance gap is normally formed between the press piece provided in a screw shaft, and a fixed piece, and it can confirm visually that the clamping | tightening by a press piece is not performed. Moreover, even if the screw shaft is advanced to the lower piece side of the metal fitting body and the grounding electrode side member is tightened between the pressing piece and the lower piece, if the tightening is not sufficient, the pressing piece and the fixing piece Since a gap is still formed between the two, it can be visually confirmed that the tightening is not sufficient. That is, if the screw shaft is advanced until there is no gap between the pressing piece and the fixing piece, it can be visually confirmed that the fastening with the pressing piece is sufficient.

  As a grounding metal fitting of the present invention, a form provided with a rotation suppression mechanism which physically suppresses rotation of a screw shaft as needed can be mentioned. In this case, the rotation suppression mechanism may be configured to include a locking nut that is screwed into a position below the upper piece of the metal fitting body on the screw shaft and above the pressing piece.

  By providing the rotation suppression mechanism, the rotation of the screw shaft can be more reliably suppressed. In the case of using the rotation suppression mechanism, it is only necessary to rotate the locking nut and send the locking nut upward.

  As an earth metal fitting of the present invention provided with a rotation suppression mechanism, the rotation suppression mechanism can include a form provided with a spring washer interposed between a locking nut and an upper piece of the metal fitting body.

  By providing the spring washer, the effect of preventing the rotation of the screw shaft by the rotation suppression mechanism can be further improved.

  On the other hand, the grounding tool of the present invention is a grounding tool for letting the current flowing through the conductive member escape to the grounding electrode side member. A grounding tool including a grounding metal fitting attached to a member, and a ground wire for electrically connecting the gripping metal fitting and the grounding metalwork. The grounding fixture of the grounding tool of the present invention is the grounding fixture of the present invention.

  According to the grounding tool including the grounding metal fitting of the present invention, it is possible to more reliably prevent the grounding metal fitting once attached to the grounding electrode side member from being detached from the grounding electrode side member. Accidents can be prevented.

(A) is a partial cross-sectional view of the ground metal fitting shown in Embodiment 1, (B) is a side view of the metal fitting body provided in the ground metal fitting shown in (A), and (C) is a handle of the ground metal fitting shown in (A). It is a top view. FIG. 2 is a partial cross-sectional view of the grounding metal when the grounding metal of FIG. (A) is a fragmentary sectional view of the grounding metal fitting shown in Embodiment 2, (B) is a top view of the handle with which the grounding metal fitting shown in (A) is equipped. FIG. 4 is a partial cross-sectional view of the grounding metal when the grounding metal of FIG. It is the schematic of the grounding tool provided with the conventional grounding metal fitting.

  Hereinafter, embodiments of the grounding tool of the present invention will be described with reference to the drawings. Here, among the grounding tools of the present invention, members other than the grounding metal are not particularly limited, and for example, the same members as those used in the conventional grounding tool with reference to FIG. 5 can be used. Therefore, in the following description, only the grounding metal provided in the grounding tool of the present invention will be described.

<Embodiment 1>
≪Overall structure≫
The grounding metal α shown in FIG. 1A includes a metal body 10, a screw shaft 20, a pressing piece 30, and a handle 40, similarly to a conventional grounding metal. The most characteristic feature of this grounding metal α is that [1] the handle 40 is configured to be movable within a predetermined range in the axial direction of the screw shaft 20, and [2] the position of the handle 40 on the screw shaft 20. The switching mechanism 1 is provided for switching between a non-transmission state in which the handle 40 is idle with respect to the screw shaft 20 and a transmission state in which the screw shaft 20 is used to rotate the handle 40. . Hereinafter, each member provided in the ground metal fitting α will be described, and which part of the members constitutes the switching mechanism 1 will be described. 1A is in a non-transmitting state, as will be described later.

≪Body body≫
As shown in FIG. 1 (A), the metal fitting body 10 is a substantially C-shaped member. The metal fitting body 10 includes an upper piece 11 and a lower piece 12 that face each other, and a side piece 13 that connects the upper piece 11 and the lower piece 12. As shown in FIG. 1B, portions of the upper piece 11 and the lower piece 12 that face each other are planar. The side piece 13 is screwed to the tip of the ground wire 103 extending from a gripping fitting (not shown).

≪Screw shaft≫
As shown in FIG. 1A, the screw shaft 20 is a member that penetrates the upper piece 11 of the metal fitting body 10. More specifically, the screw shaft 20 can be divided into an upper part, an intermediate part, and a lower part in order from the upper side of the page, and screw grooves are formed in the upper part of the upper part and the outer peripheral surface of the intermediate part. There is no thread in the lower part. Moreover, the outer diameter of the intermediate part is thicker than the outer diameters of the upper part and the lower part, and the thickest intermediate part is screwed into the upper piece 11 of the main body 10. When the screw shaft 20 is rotated, the entire screw shaft 20 advances and retreats with respect to the upper piece 11.

  On the upper part of the screw shaft 20, a hexagonal nut-like projecting portion 21 that projects outward in the radial direction from the intermediate portion of the screw shaft 20 is provided. The lower end of the overhang portion 21 is stopped by a step formed at the boundary between the upper portion and the middle portion of the screw shaft 20, and the overhang portion 21 is fixed at the position of the step. Of the six side surfaces of the overhang portion 21, ball plungers 210 are provided on every other three side surfaces. The ball plunger 210 includes a ball fitted into a hole extending radially inward of the overhang portion 21 and a plunger spring disposed between the ball and the bottom of the hole. Part of it.

  A fixing piece 23 is provided below the screw shaft 20 so as to project outward in the radial direction from the middle portion of the screw shaft 20. The upper end of the fixing piece 23 is abutted against a step formed at the boundary between the lower part and the middle part of the screw shaft 20, and the fixing piece 23 is fixed at the position of the step. On the lower side of the fixed piece 23, a fixed piece concave portion 230 for accommodating a later-described confirmation mechanism spring S2 is formed.

  Further, a stopper portion 22 is provided at the lower end of the screw shaft 20. The detachment preventing portion 22 is for preventing a pressing piece 30 described later from dropping from the lower end of the screw shaft 20.

  In addition, a locking nut N2, a washer W1, and a spring washer W2 are disposed at a position below the upper piece 11 and above the fixed piece 23 in the middle portion of the screw shaft 20. The locking nut N2 is screwed onto the screw shaft 20, and the washer W1 and the spring washer W2 are passed through the screw shaft 20 between the upper piece 11 and the locking nut N2. These members N2, W1, and W2 constitute a rotation suppression mechanism 4 to be described later.

≪Pressing piece≫
The pressing piece 30 is a member that is loosely fitted to the tip of the lower portion of the screw shaft 20 (that is, the tip of the screw shaft 20 on the lower piece 12 side of the metal fitting body 10). The grounding metal α is attached to the grounding electrode side member by sandwiching and tightening the grounding electrode side member between the pressing piece 30 and the lower piece 12 of the metal fitting body 10.

  The pressing piece 30 is formed with a tip engaging recess 300 and a through hole connected to the tip engaging recess 300, and the tip of the lower portion of the screw shaft 20 is passed through the through hole. At the tip of the lower part of the screw shaft 20, a detachment preventing part 22 is formed by attaching a cap-like member having an outer diameter larger than that of the through hole. The stopper part 22 has a function of preventing the pressing piece 30 from dropping from the lower end of the screw shaft 20. For this reason, the pressing piece 30 is loosely fitted to the lower end of the screw shaft 20 so as to be rotatable and movable in the axial direction of the screw shaft 20. In addition, after attaching the press piece 30 to the front-end | tip of the screw axis | shaft 20, you may form the anti-separation part 22 by crimping the front-end | tip of the screw axis | shaft 20. FIG. Also in this case, the tip end of the screw shaft 20 is caulked so that the outer diameter of the locking part 22 is larger than the through hole of the pressing piece 30.

  A confirmation mechanism spring S <b> 2 is disposed between the upper end surface of the pressing piece 30 and the bottom of the fixing piece recess 230 of the fixing piece 23. Therefore, the pressing piece 30 is normally urged toward the distal end of the lower portion of the screw shaft 20 and is in a state of being separated from the fixing piece 23.

≪Handle≫
The handle 40 is a portion that is gripped by an operator in order to rotate the screw shaft 20. As shown in FIG. 1C, the handle 40 according to the present embodiment is a disk-like body formed with a wavy outline, and has a through hole that penetrates the upper portion of the screw shaft 20. . Here, the shape of the handle 40 is not limited to the shape shown in FIG. For example, it may be a disc-like handle having a groove that prevents slippage on its peripheral surface, or a handle shaped like a head portion of a thumbscrew, or a rod-like handle as shown in a second embodiment described later. Also good as a handle.

  A cylindrical portion 41 is integrated with the lower end surface of the handle 40. The inner diameter of the cylindrical portion 41 is gradually reduced from the bottom to the top. When the portions having different inner diameters are the first inner diameter portion, the second inner diameter portion, the third inner diameter portion, and the fourth inner diameter portion in order from the lower side, the inner peripheral surface shape of the second inner diameter portion is the outer periphery of the overhang portion 21. It has a hexagonal shape along the surface shape. That is, the second inner diameter portion has a shape that fits with the protruding portion 21 when the tubular portion 41 is moved downward, and constitutes a switching recess 410 of the switching mechanism 1 described later. The switching recess 410 is provided with six maintenance recesses 419 provided at equal intervals in the circumferential direction. This maintenance recessed part 419 comprises the transmission state maintenance mechanism 2 mentioned later with the ball plunger 210 provided in the overhang | projection part 21. As shown in FIG.

  On the other hand, the inner peripheral surface shape of the inner diameter portion other than the second inner diameter portion is circular. The inner diameter of the first inner diameter portion is larger than the outer diameter (hexagonal circumscribed circle diameter) of the overhang portion 21, and the inner diameter of the third inner diameter portion is larger than the outer diameter of the switching mechanism spring S1 described later. Yes. The inner diameter of the fourth inner diameter portion is smaller than the outer diameter of the switching mechanism spring S <b> 1 and larger than the outer diameter of the upper portion of the screw shaft 20.

  Between the cylindrical part 41 and the overhang | projection part 21 mentioned above, the spring S1 for switching mechanisms which comprises some switching mechanisms 1 mentioned later is arrange | positioned. More specifically, the switching mechanism spring S1 is disposed inside the cylindrical portion 41, and an annular member 41c in which one end surface is fitted into the upper surface of the overhanging portion 21 and the other end surface is fitted into the cylindrical portion 41. Abut. The handle 40 including the cylindrical portion 41 is biased upward by the switching mechanism spring S1. Here, a stopper N <b> 1 made of a nut is screwed onto the upper portion of the screw shaft 20. The stopper N1 prevents the handle 40 biased by the switching mechanism spring S1 from falling off the screw shaft 20 and defines the upper end position of the handle 40. By this stop portion N1, the overhang portion 21 is disposed at the position of the first inner diameter portion located below the switching recess 410 (second inner diameter portion).

≪Switching mechanism≫
As described above, the ground metal fitting α having the configuration described above has a non-transmission state in which the handle 40 is idle with respect to the screw shaft 20 depending on the position of the handle 40 in the axial direction of the screw shaft 20, and the screw shaft 20 is A switching mechanism 1 that switches between a transmission state that is used for rotation of the handle 40 is provided. The switching mechanism 1 in the present embodiment includes an overhang portion 21 provided on the screw shaft 20, a tubular portion 41 provided on the handle 40, and a switching mechanism disposed between the overhang portion 21 and the tubular portion 41. It is comprised by the spring S1 and the stop part N1 provided in the upper side edge part of the screw shaft 20. As shown in FIG.

  The grounding metal α shown in FIG. 1A is in a non-transmitting state in which the handle 40 is idle with respect to the screw shaft 20. The reason why the handle 40 idles with respect to the screw shaft 20 is that the handle 40 is moved upward by the switching mechanism spring S <b> 1 and the overhanging portion 21 is disposed on the first inner diameter portion of the cylindrical portion 41. . As described above, since the inner diameter of the first inner diameter portion is larger than the outer diameter (hexagonal circumscribed circle diameter) of the overhanging portion 21, the cylindrical portion can be turned even if the handle 40 including the cylindrical portion 41 is rotated. The first inner diameter portion 41 is not caught by the overhanging portion 21 and is idled. Moreover, the cylindrical part 41 covers the outer periphery of the overhang part 21, and the external force is prevented from acting directly on the overhang part 21.

  Next, in order to switch from the non-transmission state to the transmission state (a state in which the screw shaft 20 rotates with the rotation of the handle 40), the handle 40 may be pushed downward with a force that overcomes the urging force of the switching mechanism spring S1. . When the handle 40 is pushed downward, as shown in FIG. 2, the step formed at the boundary between the second inner diameter portion (switching recess 410) and the third inner diameter portion of the tubular portion 41 is above the overhang portion 21. The handle 40 can be pushed in until it comes into contact with the end face. At this time, when the overhanging portion 21 is fitted in the switching recess 410 and the handle 40 is rotated, the screw shaft 20 is brought into rotation for the rotation of the handle 40. The rotation occurs because the switching recess 410 has a hexagonal shape along the outer diameter of the overhanging portion 21, so that the switching recess 410 is caught at the corner of the overhanging portion 21 when the handle 40 is rotated. It is.

≪Other mechanisms≫
In addition to the switching mechanism 1 described above, the ground metal fitting α according to the present embodiment is provided with a transmission state maintaining mechanism 2, a tightening state confirmation mechanism 3, and a rotation suppression mechanism 4. In the following, the role of each mechanism and which member of the grounding metal α is an element constituting each mechanism will be described.

[Transmission state maintenance mechanism]
The transmission state maintaining mechanism 2 is a mechanism that maintains the transmission state without pressing the handle 40 by hand. In the present embodiment, the transmission maintaining mechanism 2 includes a ball plunger 210 provided in the overhang portion 21 and a maintenance recess 419 provided at the position of the switching recess 410 in the tubular portion 41. As described above, the six maintenance recesses 419 are formed at equal intervals in the circumferential direction at the position of the switching recess 410.

  As shown in FIG. 2, when the handle 40 including the tubular portion 41 is pushed into the overhanging portion 21 side (the lower side in the drawing), the ball of the ball plunger 210 is fitted into the retaining recess 419, and the overhanging portion 21 and The cylindrical part 41 is integrated. As a result, even if the hand is released from the handle 40, the protruding portion 21 and the switching recess 410 formed in the tubular portion 41 are fitted, that is, the screw shaft 20 is rotated to rotate the handle 40. The transmission state to be maintained is maintained.

  In order to release the transmission state, the handle 40 including the tubular portion 41 may be pulled in a direction away from the overhanging portion 21 (upward on the paper surface). If the pulling force exceeds the threshold value, the ball of the ball plunger 210 is retracted radially inward of the overhanging portion 21 and the tubular portion 41 moves away from the overhanging portion 21. As a result, the protruding portion 21 is disengaged from the switching recess 410 formed in the cylindrical portion 41, that is, a non-transmission state in which the handle 40 is idle with respect to the screw shaft 20 (see FIG. 1A).

[Tightening condition check mechanism]
The tightening state confirmation mechanism 3 visually confirms the tightening state when a grounding pole side member such as a metal armature of a steel tower is tightened between the pressing piece 30 and the lower piece 12 of the metal fitting body 10. This is a mechanism that can be used (refer to any of FIGS. 1 and 2). With this tightening state confirmation mechanism 3, it is possible to prevent the mounting state from becoming insufficient when the grounding metal α is attached to the grounding electrode side member. The tightening state confirmation mechanism 3 in this embodiment includes a pressing piece 30, a fixing piece 23, and a confirmation mechanism spring S2.

  As already described, the pressing piece 30 is normally urged toward the tip of the lower part of the screw shaft 20 and is separated from the fixing piece 23. That is, by visually confirming that the pressing piece 30 and the fixed piece 23 are separated from each other, it can be confirmed that the pressing piece 30 is not tightened. Further, even if the screw shaft 20 is advanced to the lower piece 12 side of the metal fitting body 10 and the ground electrode side member is fastened between the pressing piece 30 and the lower piece 12, the tightening is not sufficient. Since a gap is still formed between the pressing piece 30 and the fixing piece 23, it can be visually confirmed that the tightening is not sufficient. That is, if the screw shaft 20 is advanced until there is no gap between the pressing piece 30 and the fixing piece 23, it can be visually confirmed that the fastening with the pressing piece 30 is sufficient.

[Rotation suppression mechanism]
The rotation suppression mechanism 4 is a mechanism that physically suppresses the rotation of the screw shaft 20 as necessary. In the present embodiment, the rotation suppression mechanism 4 includes a loosening prevention nut N2, a washer W1, and a spring washer W2.

  The timing of using the rotation suppression mechanism 4 is specifically after the grounding metal α is attached to the grounding pole side member and the grounding metal α is in a non-transmitting state. When the rotation suppression mechanism 4 is used, the loosening prevention nut N2 may be rotated and the loosening prevention nut N2 may be sent upward. The effect of suppressing the rotation of the screw shaft 20 by the loosening prevention nut N2 is very strong, and the rotation of the screw shaft 20 can be almost completely prevented. As a result, it is possible to almost certainly prevent the earth metal fitting α from being detached from the ground electrode side member.

<Embodiment 2>
In the second embodiment, a ground metal fitting β in which the configuration of the switching mechanism and the transmission state maintaining mechanism is different from that of the first embodiment will be described with reference to FIGS. Hereinafter, the difference from the first embodiment will be mainly described.

≪Screw shaft≫
The screw shaft 20 ′ of the present embodiment includes an upper part having a thread groove formed on the outer peripheral surface, and a lower part having a smaller diameter than the upper part. The configuration below the portion of the screw shaft 20 ′ that is screwed to the metal fitting body 10 is the same as that of the first embodiment.

≪Overhang part≫
A ball plunger is not formed on the overhang portion 21 ′ of the present embodiment. That is, the overhang portion 21 'is a simple hexagonal nut-like member.

≪Handle≫
As shown in FIG. 3B, the handle 40 ′ of this embodiment is a rod-shaped body. This shape has no particular meaning, and may be a disk-like body, similar to the handle 40 of the first embodiment.

≪Cylindrical part≫
Similarly to the inner diameter of the cylindrical portion 41 of the first embodiment, the inner diameter of the cylindrical portion 41 ′ of the present embodiment is gradually reduced from the lower side toward the upper side. However, the parts with different inner diameters are divided into three parts, a first inner diameter part, a second inner diameter part, and a third inner diameter part, from the lower side, and the second inner diameter part is a switching recess 410.

≪Nut for maintenance mechanism≫
In the present embodiment, the maintenance mechanism nut N3 is screwed onto the screw shaft 20 ′ above the handle 40 ′. The maintenance mechanism nut N3 is movable in the axial direction of the screw shaft 20 ′ by rotating. The maintenance mechanism nut N3 is a constituent member of the transmission state maintenance mechanism 2 ′ and also serves as a stop portion of the switching mechanism 1 ′.

≪Switching mechanism≫
The switching mechanism 1 ′ of the present embodiment includes an overhang portion 21 ′, a cylindrical portion 41 ′, a switching mechanism spring S1, and a maintenance mechanism nut N3 (stopping portion). The switching mechanism between the transmission state and the non-transmission state by the switching mechanism 1 ′ is the same as in the first embodiment. That is, when the overhanging portion 21 ′ and the switching recess 410 of the tubular portion 41 ′ are fitted, the ground metal fitting β is in a transmission state, and when the overhanging portion 21 ′ and the switching recess 410 are separated, the grounding metal β Becomes a non-transmission state.

≪Transmission state maintenance mechanism≫
The transmission state maintaining mechanism 2 ′ of the present embodiment is configured by a maintaining mechanism nut N3. First, in the non-transmission state shown in FIG. 3A, the maintenance mechanism nut N3 functions as a stop portion of the switching mechanism 1 ′, and the switching recess 410 provided in the overhanging portion 21 ′ and the cylindrical portion 41 ′. Specifies the upper limit of the separation distance. Here, the overhang portion 21 ′ is disposed at the position of the first inner diameter portion of the tubular portion 41 ′ and is protected from the outside by the tubular portion 41 ′.

  Next, when switching from the non-transmission state to the transmission state, as shown in FIG. 4, the maintenance mechanism nut N3 is rotated and the maintenance mechanism nut N3 is sent downward. Along with the feeding, the tubular portion 41 ′ also moves downward, the overhang portion 21 ′ and the switching recess 410 of the tubular portion 41 ′ are fitted, and the ground metal fitting β is switched from the non-transmission state to the transmission state. . At this time, since the maintenance mechanism nut N3 restricts the upward movement of the tubular portion 41 ', the transmission state is maintained. Needless to say, after the cylindrical portion 41 ′ is moved downward by hand, the maintenance mechanism nut N <b> 3 may be sent downward to maintain the transmission state.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications within a range not departing from the gist of the present invention. For example, the switching mechanism may be formed by providing a cylindrical portion on the screw shaft and an overhang portion on the handle.

  The grounding tool of the present invention can be suitably used for maintenance work of an overhead power transmission line.

α, β grounding bracket 1, 1 'switching mechanism 2, 2' transmission state maintaining mechanism 3 tightening state confirmation mechanism 4 rotation suppression mechanism 10 bracket main body 11 upper piece 12 lower piece 13 side piece 20, 20 'screw shaft 21, 21 'Overhanging portion 210 Ball plunger 22 Retaining prevention portion 23 Fixed piece 230 Fixed piece concave portion 30 Pressing piece 300 Tip engagement concave portion 40, 40' Handle 41, 41 'Cylindrical portion 410 Switching concave portion 419 Maintenance concave portion 41c Ring member S1 switching Spring for mechanism S2 Spring for confirmation mechanism N1 Stopper N2 Locking nut N3 Nut for maintenance mechanism (Stopper)
W1 Washer W2 Spring washer 100 Grounding tool 101 Insulating rod 102 Grip metal fitting 103 Ground wire 104 Ground metal fitting 104a Metal fitting body 104b Screw shaft 104c Pressing piece 104d Handle 200 Conductive member

Claims (8)

It is a grounding fixture used for a grounding tool that grips a conductive member with a gripping bracket provided at the tip of an insulating rod and releases the current flowing through the conductive member to the grounding pole side member,
An upper piece and a lower piece that face each other, and a side piece that connects the upper piece and the lower piece, and a metal fitting body to which a ground wire extending from the gripping metal fitting is connected,
A screw shaft that passes through the upper piece and is screwed forward and backward with respect to the upper piece;
Of the screw shaft, a press piece loosely fitted to the tip on the lower piece side and sandwiching the grounding electrode side member between the lower piece,
A handle that is provided above the upper piece of the screw shaft and rotates around the axial direction of the screw shaft when an operator rotates the screw shaft;
A grounding metal fitting comprising:
The handle is configured to be movable within a predetermined range in the axial direction of the screw shaft,
A grounding fixture comprising a switching mechanism that switches between a non-transmission state in which the handle is idle with respect to the screw shaft and a transmission state in which the screw shaft is used for rotation of the handle depending on the position of the handle on the screw shaft. . The switching mechanism is
An overhang portion that is integrated with the screw shaft and projects outward in the radial direction of the screw shaft;
A tubular portion integrated with the handle and having a switching recess along the outer shape of the overhang;
A spring for a switching mechanism that is disposed between the projecting portion and the tubular portion and biases the handle including the tubular portion in a direction away from the projecting portion;
A stop portion provided on the screw shaft and defining an upper limit value of a separation distance between the handle and the overhang portion;
With
The overhanging portion and the switching recess are fitted to be in the transmission state, and the overhanging portion and the switching recess are separated by the biasing force of the switching mechanism spring so that the non-transmission state is established. The earthing | grounding metal fitting of Claim 1 comprised by these.   The grounding metal fitting according to claim 2, further comprising a transmission state maintaining mechanism that maintains a state in which the projecting portion and the switching recess are fitted. The transmission state maintaining mechanism is
A ball plunger provided in the overhang,
A maintenance recess provided at a position of the switching recess in the tubular portion, into which a ball of the ball plunger is fitted;
The grounding metal fitting according to claim 3 provided with. A tightening state confirmation mechanism for visually confirming the tightening state of the grounding electrode side member by the pressing piece and the lower piece;
The tightening state confirmation mechanism is
A fixed piece that is fixed below the upper piece of the screw shaft and above the pressing piece;
Is interposed between the fixing piece and the pressing piece, a spring for confirmation mechanism for biasing the pressing piece below the said screw shaft,
The grounding metal fitting according to any one of claims 1 to 4. A rotation suppression mechanism that physically suppresses rotation of the screw shaft as necessary,
The said rotation suppression mechanism is provided with the loosening prevention nut screwed together in the position below the said upper piece in the said screw shaft, and the said press piece. Earthing hardware.   The ground metal fitting according to claim 6, wherein the rotation suppression mechanism includes a spring washer interposed between the loosening prevention nut and the upper piece. It is a grounding tool that releases the current flowing through the conductive member to the grounding pole side member,
An insulating rod;
A holding fitting provided at the tip of the insulating rod and holding the conductive member;
A grounding fitting attached to the grounding electrode side member;
A ground wire for electrically connecting the gripping fitting and the grounding fitting;
A grounding tool comprising:
The grounding tool whose grounding metal fitting is the earthing metal fitting as described in any one of Claims 1-7.

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