JP4953134B2 - Grounding tool - Google Patents

Description

  The present invention relates to a grounding tool for grounding when a jumper wire is opened. In particular, the present invention relates to a grounding tool that can be carried out without mistakes in attaching and detaching the grounding tool to / from the conductive member, and can prevent an electric shock accident.

  An overhead power transmission line normally transmits power through two 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 a grounding 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. 8 is a schematic configuration diagram of a hook-type grounding tool as described in FIG. The grounding tool 100 includes a telescopic insulating rod 101, a holding fitting 102 provided at the tip of the insulating rod 101, and a grounding fitting 104 connected to the holding fitting 102 via a ground wire 103. The grounding tool 100 is attached by first connecting the grounding metal fitting 104 to a grounding object such as a steel tower, and then extending the insulating rod 101 and holding the conductive member 200 such as an electric wire or a grounded metal fitting by the holding metal fitting 102. Do. By this work, current can be released from the conductive member 200 to the grounded object via the gripping fitting 102, the grounding wire 103, and the grounding 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 metal fitting 102 to shorten the insulating rod 101 and then removing the grounding metal piece 104 from the grounding object.

JP 2000-278830 A

  By the way, in the grounding tool described in Patent Document 1, there is a possibility that an electric shock accident may occur due to an error in the attachment / detachment procedure to / from the conductive member.

  When the grounding tool is attached, the grounding metal must be connected to the grounding object before the current can be released to the grounding object when the conductive member is gripped by the gripping metal. Therefore, when the insulating rod is extended before the grounding metal is attached to the object to be grounded and the conductive member is gripped by the gripping metal, and then touched to the grounding metal, the operator is electrocuted by the current from the overhead power transmission line. Similarly, when removing the grounding tool from the conductive member, an electric shock accident occurs if the grounding member is touched before releasing the gripping of the conductive member by the gripping bracket.

  Such an error in the procedure for attaching / detaching the grounding tool may be caused by a reduction in attention due to habituation even for those skilled in the work.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a grounding tool that can eliminate an electric shock accident due to an error in attaching / detaching a grounding tool.

  The present invention achieves the above object by mutually restricting the attachment / detachment of the grounding metal to / from the grounding object and the extension of the insulating rod that is extended when the conductive member is gripped.

  The present invention includes a retractable insulating rod, a gripping bracket that is attached to the tip of the insulating rod and grips the conductive member, and a grounding bracket that is connected to the gripping bracket via a ground wire, and flows to the conductive member It is a grounding tool that releases current to ground. Furthermore, the grounding tool of the present invention includes an interlock mechanism that restricts the extension operation of the insulating rod, and a key fitting that can be attached to and detached from the earth fitting and the interlock mechanism.

  The grounding fixture of the grounding tool of the present invention includes a fastening mechanism for fastening a grounding object, a first key fitting mounting portion for attaching the key fitting, a fastening operation lock mechanism for restricting a fastening operation of the fastening mechanism, and a first key fitting. A first key operation restriction mechanism for restricting attachment / detachment of the key fitting from the attachment portion.

  The earth metal fitting tightening mechanism is a mechanism for fixing the earth metal fitting to the grounding object by fastening the earthing object such as a steel tower. In addition, this earth metal fitting tightening operation locking mechanism is a mechanism that enables a tightening operation by the tightening mechanism when the key fitting is attached to the first key fitting attaching portion. According to this mechanism, the ground metal cannot be attached to the grounding object unless the key metal is attached to the first key metal attachment portion of the ground metal. In other words, in the grounding tool of the present invention before the grounding work is performed, the key fitting is attached to the grounding fitting.

  In addition, the first key operation restriction mechanism of the ground metal fitting is a mechanism that allows the key metal fitting to be removed from the first key metal fitting mounting portion when the tightening amount of the tightening mechanism exceeds a predetermined amount. is there. According to this mechanism, the key fitting cannot be removed from the first key fitting mounting portion unless the ground fitting is attached to the grounding target.

  On the other hand, an interlock mechanism has the 2nd key metal fitting attaching part which attaches a key metal fitting. The interlock mechanism is configured to be in the unlocked state in which the extension operation of the insulating rod can be performed by attaching the key fitting to the second key fitting attaching portion. In other words, the insulating rod cannot be extended in a state where the key fitting is not attached to the second key fitting attaching portion. Here, as described above, the key fitting attached to the grounding fitting can be removed only after the earthing fitting is attached to the grounding object, as described above. The key fitting attached to the earth fitting cannot be removed and the key fitting cannot be attached to the interlock mechanism. Therefore, when grounding is performed with the grounding tool of the present invention, the grounding member is always attached to the grounding object, and then the insulating rod is extended and the conductive member is gripped by the gripping bracket.

  As described above, according to the grounding tool of the present invention, the procedure for performing the grounding operation, that is, the procedure for attaching the grounding tool can be limited to the correct procedure. On the other hand, when releasing the grounding by the grounding tool of the present invention, it is possible to visually confirm that the key fitting is not attached to the grounding fixture. Prior to shortening, touching the grounding hardware can be substantially eliminated.

  The key fitting is preferably colored in order to make it easy to visually confirm whether it is attached to the earth fitting or the interlock fitting.

  Here, the interlock mechanism may be provided with a second key operation restriction mechanism for restricting the attachment / detachment of the key fitting from the second key fitting mounting portion. This second key operation restriction mechanism is configured to prevent the key fitting from being removed from the second key fitting mounting portion when in the unlocked state in which the insulating rod can be extended. According to this configuration, since the key fitting is always attached to the interlock mechanism while the insulating rod is extended, it is sure to touch the grounding fitting while holding the electric wire with the holding fitting. Can be eliminated.

  Hereinafter, preferred embodiments of (1) the configuration of the ground metal fitting, (2) the configuration of the interlock mechanism, and (3) other configurations will be described.

(1) Configuration of Grounding Metal Next, a preferable configuration of the grounding metal will be described. The ground metal fitting includes a ground metal fitting body, a key fitting insertion hole into which the key fitting can be inserted, a tightening mechanism, a tightening operation lock mechanism, and a key operation restriction mechanism. Note that the key fitting used for the earth fitting has a key body and a step portion formed at an intermediate portion of the key body.

  First, the tightening mechanism includes a screw shaft that can be moved forward and backward with respect to the earth metal fitting body so that a part of the peripheral surface is exposed in the key metal fitting insertion hole, and a grounding object that presses the earthing object at the tip. Is sandwiched between the clamping piece and the pressing piece.The clamping piece is placed at a position facing the tip of the screw shaft across the pin and supported by the grounding metal body so that it can move in the direction in which the grounding object is pressed. And a first elastic body that urges the holding piece in a direction to tighten the grounding object. When attaching the grounding bracket to the grounding object with this tightening mechanism, place the grounding object between the clamping piece and the pressing piece of the screw shaft, and press the grounding object with the pressing piece to make the grounding object a clamping piece. Press. At this time, the clamping piece pressed by the grounding object moves in the pressing direction of the screw shaft, but the grounding object is moved between the screw shaft and the clamping piece by an elastic body that urges the clamping piece in the direction of the screw shaft. Can be tightened.

  As the tightening operation lock mechanism for restricting the tightening operation of the tightening mechanism using the screw shaft, there is a configuration that prevents the screw shaft from rotating unless a key fitting is inserted. Specifically, the screw shaft is formed with a notch surface in which a part of its peripheral surface is cut out, and is disposed inside the key fitting insertion hole, and is brought into contact with the notch surface so that the screw shaft An anti-rotation member having an abutment surface that restricts rotation is provided. Further, the detent member that restricts the rotation of the screw shaft is moved in conjunction with the insertion / removal operation of the key fitting. Specifically, when a second elastic body is provided to urge the locking member in the opening direction of the key fitting insertion hole, and the key fitting is not inserted into the key fitting insertion hole (is removed) The contact surface of the rotation preventing member is disposed at a position facing the notch surface of the screw shaft. When trying to rotate the screw shaft in this state, the notch surface of the screw shaft contacts the contact surface of the rotation preventing member, and the rotation of the screw shaft is suppressed. Also, when the key fitting is inserted into the key fitting insertion hole, press the locking member with the tip of the key fitting so that the contact surface of the locking member does not contact the notch surface of the screw shaft. By moving, rotation of the screw shaft is allowed.

  Here, if a marker indicating the direction in which the cut-out surface is facing is provided at a position on the screw shaft that protrudes from the ground bracket, it is easy to check whether the cut-out surface is exposed in the key bracket insertion hole. It is preferable because it is possible.

  According to the tightening operation lock mechanism as described above, the screw shaft can be rotated only when the key fitting is inserted into the key fitting insertion hole of the earth fitting. Due to the elasticity of the elastic body, when the key fitting is removed, the anti-rotation member advances inside the key fitting insertion hole, and the contact surface of the anti-rotation member faces the notch surface of the screw shaft.

  In addition, as a key operation restriction mechanism for restricting removal of the key fitting in the earth fitting, a configuration in which the key fitting is locked in conjunction with the tightening operation of the screw shaft can be cited. Specifically, it is attached to the ground metal fitting body so that it can advance and retreat inside the key fitting insertion hole, and it is fixed so that the key fitting does not come out of the key insertion hole by engaging with the step of the key fitting. And a pin metal fitting that is attached to the metal body so as to be able to advance and retreat with respect to the pin metal. Then, one end of the pin metal fitting is fixed to the holding piece, and the other end is engaged with the pin metal to fix the pin metal. According to such a configuration, when the screw shaft is rotated and the holding piece is moved by a predetermined amount in the pressing direction of the screw shaft, the fixing of the pin metal fitting by the pin metal fitting is released. it can. Since the pin fitting that has been released can be moved freely, the key fitting can be removed from the key fitting insertion hole by retracting the pin fitting from the key fitting insertion hole.

  In addition, as a configuration suitable for the ground metal fitting, it is possible to provide a pressing piece that is loosely fitted to the tip of the screw shaft and presses the grounding object without rotating together with the rotation of the screw shaft. For example, as shown in an embodiment described later, a bottomed cylindrical pressing piece is loosely fitted to the tip of the screw shaft, and a compression spring is disposed in the pressing piece. With this configuration, when the screw shaft is rotated to bring the pressing piece into contact with the grounding object, the screw shaft is idled even if the screw shaft is further rotated, so that the friction between the pressing piece and the grounding object is reduced. Even if it is large, the screw shaft can be easily rotated, and even if the screw shaft idles, the grounding object can be pressed to the holding piece side by the pressing piece.

(2) Structure of interlock mechanism The structure of the interlock mechanism includes an engagement fitting fixed to the insulating rod, an interlock fitting engaged with the engagement fitting, and a latch connecting the insulation rod and the interlock fitting. A configuration using a rope is preferable. The locking cord maintains the contracted state of the insulating rod when the engagement fitting and the interlock fitting are engaged. Typically, one end of the locking cord is fixed to the insulating rod and the other end is fixed to the interlock metal fitting. At this time, by making the locking cord straddle the extension mechanism of the insulating rod, when the engagement fitting and the interlock fitting are engaged, the insulating rod cannot extend beyond the length of the locking cord. Can be. For example, when using a mechanism in which a plurality of cylindrical members are nested like a special baton as an extension mechanism of an insulating rod, an engagement metal fitting is held on the cylindrical member on the inner peripheral side, and this cylindrical member Also, one end of the locking cord is fixed to the cylindrical member on the outer peripheral side. In this case, since the other end of the locking cord is fixed to the interlock mechanism, the insulating rod can be extended beyond the length of the locking cord when the interlock fitting and the engagement fitting are engaged. Can be eliminated.

  The locking cord may have a length that maintains the contracted state of the insulating rod, or a length that is adjusted by the length adjusting member to maintain the contracted state of the insulating rod. good. As the length adjusting member, a member that adjusts the length of the locking cord by folding and binding the locking cord may be used. When such a length adjusting member is used, for example, when one end of the locking cable is fixed to the interlock metal fitting and the other end side is passed through a ring provided on the insulating rod, the folded length is set. It should be fixed. Alternatively, one end of the locking cord may be fixed to the insulating rod, the other end side may be folded through a ring provided on the interlock metal fitting, and the folded length may be fixed by the length adjusting member. Here, since the locking cord extends along the insulating rod, there is a possibility that it may become an obstacle when grasping the insulating rod. However, if the length adjusting member is used, the length of the locking cord can be reduced. It is possible to make the length with play that does not get in the way when grasping the insulating rod while restricting extension.

  Furthermore, it is preferable that the locking cable is configured to be automatically wound when the engagement between the interlock metal fitting and the engagement metal fitting is released. For example, the locking cable is extended from the winding device, and the winding device is fixed to the insulating rod. Here, the winding device fixes the winding device to the end portion (rear end portion) on the opposite side of the gripping metal among the insulating rods, and the end portion side of the locking cord fed out from the winding device is fixed. It is preferable to be configured to be connected to an interlock metal fitting. In this configuration, when the engagement between the interlock metal fitting and the engagement metal fitting is released, the locking cable is automatically wound up, and the vicinity of the winding device that fixes the interlock metal fitting to the insulating rod Since it can be placed in, it does not get in the way of work.

  In addition, the interlock fitting of the interlock mechanism has a lock release hole into which the key fitting can be inserted, and the engagement between the engagement fitting and the interlock fitting can be released by inserting the key fitting into the lock release hole. Like that.

  Furthermore, the preferable structure of the interlock metal fitting and engagement metal fitting of the interlock mechanism mentioned above is demonstrated.

  First, an engagement fitting that engages with the interlock fitting is formed in a block shape. Then, a retaining hole penetrating in the thickness direction of the block-shaped main body, and a slit having one end communicating with the retaining hole and the other end opened to the outside of the block-shaped main body are provided. This slit. The width is smaller than the diameter of the retaining hole. In addition, the key fitting in this preferable configuration is configured to have a key body, a step portion provided at an intermediate portion of the key body, and a tip portion protruding from the tip of the key body. The tip of the key fitting is formed with a diameter smaller than the width of the slit of the engagement fitting.

  The interlock metal fitting is provided with an engagement metal fitting insertion hole into which the engagement metal fitting can be inserted so as to intersect the lock release hole. By crossing the engagement metal fitting insertion hole and the lock release hole, when the engagement metal fitting is inserted into the engagement metal fitting insertion hole, the retaining hole of the engagement metal fitting can be arranged at the position of the lock release hole. . The reason why the retaining hole of the engagement fitting is arranged at this position will be described later.

  Further, among the unlocking holes, a locking piece that is disposed at a position opposite to the opening of the unlocking hole across the engagement fitting insertion hole intersecting the unlocking hole and movable in the axial direction of the unlocking hole, And a third elastic body for biasing the lock piece toward the opening of the unlocking hole. The lock piece includes a tip piece having a diameter smaller than the inner diameter of the retaining hole and larger than the width of the slit.

  When the engagement fitting is inserted into the engagement fitting insertion hole of the interlock fitting due to the configuration of the engagement fitting insertion hole, the lock release hole and the lock piece as described above, the lock intersecting with the engagement fitting insertion hole The tip piece of the lock piece can be inserted into the retaining hole of the engagement fitting at the position of the release hole. Here, since the diameter of the front end piece of the lock piece is larger than the width of the slit of the engagement metal fitting, the edge of the slit is held against the front piece and the engagement metal fitting and the interlock metal fitting can be engaged. it can.

  When the key fitting is inserted into the unlocking hole from the state where the engagement fitting and the interlock fitting are engaged, the tip of the lock piece is pressed by the tip of the key fitting, and the engagement fitting is removed. The tip piece of the lock piece can be withdrawn from the stop hole. The distal end portion of the key fitting in which the distal end piece of the lock piece is retracted from the retaining hole is disposed in the retaining hole of the engagement fitting instead of the distal end piece of the lock piece. At this time, since the diameter of the tip of the key fitting is smaller than the width of the slit of the engagement fitting, the engagement fitting can be made detachable from the engagement fitting insertion hole of the interlock fitting. That is, the engagement between the engagement fitting and the interlock fitting can be released.

  Furthermore, it is preferable to provide a key operation restriction mechanism for restricting removal of the key fitting from the unlocking hole when the engagement between the interlock fitting and the engagement fitting is released. The key operation restriction mechanism is a claw fitting that is placed in the back of the engagement fitting insertion hole and can be moved back and forth in the direction intersecting the axial direction of the unlocking hole, and the claw fitting is urged in the opening direction of the engagement fitting insertion hole. The fourth elastic body is configured. With such a configuration, when the engagement fitting is not inserted into the engagement fitting insertion hole, that is, when the key fitting is inserted into the unlocking hole, a part of the claw fitting is advanced into the unlocking hole. Thus, the stepped portion of the key fitting can be stopped by a part of the claw fitting that has advanced. As a result, it is possible to prevent the key fitting from being removed from the lock release hole. On the other hand, when the engagement fitting is inserted into the engagement fitting insertion hole, the claw fitting arranged at the back of the engagement fitting insertion hole is pushed by the engagement fitting and moves to the lock release hole. A part of the claws can be withdrawn from the unlocking hole. As a result, there is no member for holding the stepped portion of the key fitting, and the key fitting can be removed from the unlocking hole of the interlock fitting.

(3) Others To prevent the key fitting from being dropped during work, it is better to connect the part of the insulation rod that is actually gripped and operated by an operator via a fall prevention cord. By doing so, even if the key fitting is dropped, the key fitting can be recovered by pulling the fall prevention cord. The key fitting may be connected to an interlock mechanism. Since the interlock fitting is always present in the vicinity of the operator, it is easy to collect the key fitting. It is preferable that the fall prevention rope is also fed out from a winding device that automatically winds the fall prevention rope in the same manner as the locking rope described above. The fall prevention rope winding device should be fixed to the insulating rod, and more preferably, if it is fixed to the rear end of the insulating rod, the key fitting that is not in the attached state can always be placed at hand. Useful when using.

  According to the grounding tool of the present invention, both the procedure of attaching the grounding tool and releasing the current flowing through the conductive member to the ground and the procedure of removing the grounding tool and releasing the grounding can be limited to correct procedures. . Therefore, it is possible to reliably prevent an electric shock accident due to a mistake in attaching and removing the grounding tool.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a grounding tool 1 according to the present invention. The grounding tool 1 includes a stretchable insulating rod 2, a gripping fitting 3 attached to the tip of the insulating rod 2, and a grounding fixture 5 connected to the gripping fitting 3 via a grounding wire 4. Further, the grounding tool 1 of the present invention includes an interlock metal fitting 6, which is a lock plate (engagement metal fitting) held near the base of the holding metal fitting 3 on the distal end side of the insulating rod 2. ) 9 is engaged. A fall prevention cable 79 extends from the interlock metal fitting 6, and a key metal fitting 7 is attached to the end of the cable. The key fitting 7 is inserted into the key fitting insertion hole (first key fitting mounting portion) of the ground fitting 5 described above. Further, a locking cord 8 extends from the interlock metal fitting 6 and is engaged with a stone hammer 28 on the rear end side of the insulating rod 2. The locking cable 8 has substantially the same length as the distance between the stone fitting 28 and the interlock fitting 6. Therefore, as long as the interlock metal fitting 6 is engaged with the lock plate 9, the insulating rod 2 cannot be extended.

  Hereinafter, constituent members of the grounding tool of the present invention will be described, and then a procedure for attaching and removing the grounding tool of the present invention will be described.

[Insulating bar]
As shown in FIG. 2 (A), the insulating rod 2 is formed by nesting four cylindrical members 21 to 24, and the cylindrical members 22 to 30 are arranged on the inner peripheral side of the cylindrical member 21. It can be extended by feeding out 24. The insulating rod 2 has a known structure so that the cylindrical members 22, 23, and 24 do not completely come out of the cylindrical members 21, 22, and 23, respectively.

  The cylindrical member 24 at the tip of the insulating rod 2 is provided with a ring groove 2g into which the lock ring 9r (see FIGS. 1 and 2D) of the lock plate 9 can be fitted. In addition, a stone hammer 28 is provided at the rear end of the insulating rod 2. The stone fitting 28 is ring-shaped, and one end of the locking cord 8 is connected as shown in FIG. The other end of the locking cable 8 is connected to the interlock metal fitting 6, and the interlock metal fitting 6 is connected to the insulating rod 2 even when the engagement between the interlock metal fitting 6 and the lock plate 9 is released. It is. Therefore, even if the operator accidentally drops the interlock metal fitting 6 from his / her hand, the interlock metal fitting 6 can be recovered by pulling the locking cord 8 by hand.

[Grip bracket]
As shown in FIG. 1, the holding fitting 3 is a member that is attached to the tip of the insulating rod 2 via a joint j and holds a conductive member such as an electric wire or a grounded fitting attached to the electric wire. A known universal joint was used as the joint j for connecting the holding fitting 3 to the insulating rod 2. With this universal joint, the gripping fitting can be bent within the movable range of the joint. In addition to the universal joint, a known ball joint may be used.

  As shown in FIG. 2 (B), the gripping bracket 3 is rotatably supported via a fixed gripping piece 31 fixed to the distal end of the insulating rod 2 and a shaft portion 33 provided on the distal end side of the fixed gripping piece 31. And a movable gripping piece 32. The gripping fitting 3 is called a hook type in order to hook the conductive member when gripping the conductive member. In addition, a tulip-shaped holding fitting as shown in FIG. 1 of Patent Document 1 may be used. The fixed grip piece 31 is provided with a ground wire mounting base 311 for connecting an end portion of the ground wire, and a ground wire lead-out hole 312 for inserting the ground wire and defining a drawing direction of the ground wire.

[Key fittings]
As shown in FIG. 2 (C), the key fitting 7 is a substantially cylindrical member, and includes a barrel portion 7b, a groove portion 7g having a diameter smaller than that of the barrel portion 7b, and a truncated cone-shaped flange portion (step portion). 7f and a tip portion 7t. Note that the diameter of the tip 7t is smaller than the inner diameter of a retaining hole 9h of the lock plate 9 described later and smaller than the width of the slit 9s of the lock plate 9 (see FIG. 2D).

  The key fitting 7 is connected to the interlock fitting 6 via a ring 7r provided at the rear end of the trunk portion 7b and a fall prevention rope 79 connected to the ring 7r (see FIG. 1). As described above, the interlock metal fitting 6 is connected to the stone metal fitting 28 of the insulating rod 2 via the locking cord 8, and is always in the vicinity of the operator. Therefore, even if the key fitting 7 connected to the interlock fitting 6 is dropped from the hand, it can be easily recovered by pulling the fall-preventing rope 79 by hand.

  The key fitting is colored to make it easy to visually confirm whether it is attached to the ground fitting or the interlock fitting. The color of the key fitting can be arbitrarily selected, but a warm color such as red or orange or a conspicuous color such as a fluorescent color is preferable.

[Earth bracket]
As shown in Fig. 3 (Fig. 3 (A) is the front, (B) is the top, (C) is a partial cross-sectional view from the side), the grounding metal 5 and the clamping plate (clamping piece) 53 and a thumbscrew (screw shaft) 52. The metal fitting body 51 is formed by integrating an upper piece 510, a lower piece 511, a side piece 512, and a back piece 513, and the upper piece 510 and the lower piece 511 are connected by a back piece 513 so as to face each other. The side piece 512 is connected to the side of the upper piece 510 and the back piece 513. A wing screw 52 is passed through the upper piece 510, and a pressing piece 52 t provided at the tip of the wing screw 52 is opposed to the lower piece 511. Further, a clamping plate 53 is disposed between the lower piece 511 and the pressing piece 52t of the thumbscrew 52. The sandwiching plate 53 can be disposed at the lower end of the side piece 512 and has a shape that does not interfere with the back piece 513 and is positioned at the lower end of the lower piece 511 by the positioning pin 531. A compression spring (first elastic body) 53s is disposed on the outer periphery of the positioning pin 531, and the clamping plate 53 is pressed in the direction of the upper piece 510 (above FIGS. 3A and 3C). . A grounding object is arranged between the clamping plate 53 and the pressing piece 52t of the butterfly screw 52 by a tightening mechanism comprising the butterfly screw 52, the clamping plate 53 and the compression spring 53s provided in the metal fitting body 51, and the butterfly screw 52 , The clamping plate 53 moves in the direction of the lower piece 511, but the grounding object can be pressed by the elasticity of the compression spring 53s, so that the grounding is made between the clamping plate 53 and the pressing piece 52t of the thumbscrew 52. The object can be tightened. As a result, the ground metal fitting 5 can be firmly fixed to the grounding object.

  Here, the pressing piece 52t in this example is configured to be loosely fitted to the tip of the shaft portion 52a of the screw shaft 52, as shown in FIG. The pressing piece 52t has a configuration in which a bottom plate is welded to a cylindrical member, and has a flange that protrudes to the inner peripheral side on the opposite side to the bottom plate. Further, a flange 52f that protrudes to the outer peripheral side of the shaft portion 52a is provided on the end portion side of the shaft portion 52a. In order to provide the pressing piece 52t at the tip of the shaft portion 52a, the shaft portion 52a is first fitted into the cylindrical member, and the flange of the cylindrical member and the flange 52f of the shaft portion 52a are engaged. Next, a compression spring (elastic body) 52s is disposed at the tip of the shaft 52a, and a bottom plate is welded to the bottom of the cylindrical member. Then, when the shaft portion 52a loosely fitted with the pressing piece 52t is screwed to the upper piece 510 of the metal fitting body, the head is welded to the shaft portion 52a. The pressing piece 52t configured as described above stops rotating due to friction between the bottom plate of the pressing piece 52t and the grounding object when it comes into contact with the grounding object as the shaft portion 52a (screw shaft 52) rotates. Further, when the screw shaft 52a is rotated, the screw shaft 52a is idled, but at this time, the tip of the shaft portion 52a pushes down the pressing piece 52t via the compression spring 52s, so that the pressed pressing piece 52t is subject to grounding. Can be pressed.

  On the upper piece 510 of the metal fitting body 51, from the side of the side piece 512 (the left direction in FIG. 3 (A) and (B)) toward the inside of the upper piece 510 (FIG. 3 (A) and (B) The key fitting insertion hole (first key fitting mounting portion) 57 is provided in the grounding tool 1 before the grounding work is performed. Is plugged in. The key fitting insertion hole 57 is provided continuously to the large diameter portion 57w and the large diameter portion 57w having an inner diameter substantially coinciding with the outer diameter of the body portion 7b of the key fitting 7, and has an inner diameter larger than that of the large diameter portion 57w. And a small small-diameter portion 57n. A part of the small diameter part 57n is provided so as to intersect a part of the shaft part 52a of the thumbscrew 52, and a part of the shaft part 52a of the thumbscrew 52 is a small diameter of the key fitting insertion hole 57. Projecting into the portion 57n. The thumbscrew 52 has a cutout surface 52p formed by cutting out a part of the shaft portion 52a. By rotating the thumbscrew 52, the cutout surface 52p is moved into the small diameter portion 57n. It can be exposed to. The notch surface 52p of the thumbscrew 52 has a certain length in the axial direction of the shaft portion 52a of the thumbscrew 52, and a part of the notch surface 52p is exposed from the upper piece 510. Can be confirmed. A marker indicating the position of the notch surface 52p may be provided on the head of the thumbscrew 52.

  An anti-rotation piece (anti-rotation member) 54 is disposed in the small diameter portion 57n of the key fitting insertion hole 57. The rotation stopper piece 54 includes a main body piece 54b and a tip piece 54t having a smaller diameter than the main body piece 54b. A compression spring (second elastic body) 54s is arranged between the main body piece 54b of the rotation stopper piece 54 and the bottom portion 57b of the key fitting insertion hole 57, and the rotation prevention piece 54 is caused by the elasticity of the compression spring 54s. The key fitting 7 is pressed in the direction of pushing out from the key fitting insertion hole 57. The notch surface 52p, the non-rotating piece 54 and the compression spring 54s of the thumbscrew 52 are tightened by the tightening mechanism only when the key fitting 7 is inserted into the key fitting insertion hole 57, as will be described in detail later. This is a tightening operation limiting mechanism that enables the state.

  On the side piece 512 of the metal fitting body 51, a pin fitting penetrating from the back side of the side piece 512 (above the plane of FIG. 3 (B)) to the key fitting insertion hole 57 in a direction perpendicular to the key fitting insertion hole 57. An arrangement hole is provided, and the pin fitting 55 is arranged in the pin fitting arrangement hole. The pin fitting 55 includes a pin tip portion 55t, a pin flange portion 55f, and a pin groove portion 55g. By pushing the pin fitting 55, the pin tip 55t can be advanced into the key fitting insertion hole 57. On the other hand, when the pin fitting 55 is pulled, the pin tip 55t of the pin fitting 55 can be retracted from the key fitting insertion hole 57. At this time, the pin flange portion 55f stops and the pin fitting 55 is prevented from falling off. The pin groove 55g of the pin metal 55 will be described later.

  In this figure, in which the key fitting 7 is inserted into the key fitting insertion hole 57, the pin fitting 55 is pushed in, and the pin tip 55t of the pin fitting 55 engages with the flange portion 7f of the key fitting 7. The key fitting 7 is locked. Therefore, as described above, even if the locking piece 54 presses the key fitting 7, the key fitting 7 is not pushed out from the key fitting insertion hole 57.

  The side piece 512 of the metal fitting body 51 is provided with a through hole that penetrates from the lower end surface of the side piece 512 (below in FIGS. 3A and 3C) to the pin metal fitting arrangement hole. The through hole is orthogonal to the pin fitting arrangement hole, and the pin fitting locking fitting 56 is inserted therethrough. Of the pin metal fitting 56, the end on the pin metal 55 side is formed in a pencil down shape. The pencil down part 56t is fitted into the pin groove part 55g of the pin metal part 55 so that the pin metal part 55 cannot be pulled. Therefore, unless the pencil down part 56t of the pin metal fitting 56 is removed from the groove 55g of the pin metal 55, the key metal 7 cannot be pulled out of the key metal insertion hole 57 by pulling the pin metal 55.

  On the other hand, a screw groove is formed at the end of the pin metal fitting 56 on the holding plate 53 side, and is fixed to the holding plate 53 with a nut n. Therefore, when the grounding object is tightened by the thumbscrew 52 and the holding plate 53 is moved downward in FIGS. 3A and 3C, the pin metal fitting 56 is also moved downward. The pin fitting 55 and the pin fitting locking fitting 56 are a first key operation restriction mechanism that restricts the attaching / detaching operation of the key fitting, as will be described in detail later.

  In addition, the lower piece 511 of the metal fitting body 51 is provided with a connection portion 514 that can connect a grounding wire, and a conductive path is formed from the above-described gripping metal fitting to the earthing fitting via the grounding wire. .

[Lock plate]
As shown in FIGS. 2D and 5, the lock plate 9 is a rectangular plate-like member that is engaged with and disengaged from the interlock fitting 6 by inserting / removing a key fitting to / from the interlock fitting 6 described later. The lock plate 9 has a retaining hole 9h that penetrates in the thickness direction, and a slit 9s that is continuous with the retaining hole 9h and opens in the rectangular short side direction of the plate. Of the slit 9s, the corner is cut out in the vicinity of the opening. Further, the lock plate 9 is provided with a lock ring 9r, and the lock ring 9r is fitted in the ring groove 2g on the distal end side of the insulating rod 2 as shown in FIG.

[Interlock metal fittings]
As shown in FIG. 5, the interlock fitting 6 is provided with a plate insertion hole (engagement fitting insertion hole) 61 for inserting the above-described lock plate 9. In the grounding tool 1 before the grounding work, The lock plate 9 is inserted into the plate insertion hole 61. The plate insertion hole 61 is a rectangular hole that substantially matches the outer shape of the lock plate 9. Further, the interlock fitting 6 is provided with a lock release hole (second key fitting mounting portion) 67 so as to intersect perpendicularly to the plate insertion hole 61. That is, a part of the lock release hole 67 and a part of the plate insertion hole 61 are used.

  The lock release hole 67 is a hole for inserting the key fitting 7. Of the unlocking hole 67, the portion from the opening to the plate insertion hole 61 is a large-diameter portion 67w substantially equal to the outer diameter of the body portion of the key fitting. Further, in the back of the plate insertion hole 61, the narrowed portion 67vn having a diameter smaller than that of the large diameter portion 67w, and in the further back of the narrowed portion 67vn, the diameter is larger than that of the narrowed portion 67vn, but the diameter is larger than that of the large diameter portion 67w. A small diameter portion 67n is provided.

  A lock piece 62 is disposed in the small diameter portion 67 n of the lock release hole 67. The lock piece 62 includes a lock piece body portion 62b and a lock piece front end portion 62t having a diameter smaller than that of the lock piece body portion 62b. A compression spring (third elastic body) 62s is disposed between the body portion 62b of the lock piece 62 and the bottom portion 67b of the lock release hole 67. The lock piece 62 is unlocked by the elasticity of the compression spring 62s. 67 is pressed in the direction of the opening. In this figure, where the lock plate 9 is inserted into the plate insertion hole 61, the tip 62t of the lock piece 62 pressed by the compression spring 62s is inserted into the retaining hole 9h of the lock plate 9. Yes. At this time, the outer diameter of the tip piece 62t of the lock piece 62 is smaller than the inner diameter of the retaining hole 9h of the lock plate 9 described above and larger than the width of the slit 9s. When trying to remove from the hole 61, the tip piece 62t is caught by the edge of the slit, which is the boundary between the retaining hole 9h and the slit 9s, so that the lock plate 9 cannot be removed from the plate insertion hole 61. (See Figure 5 (A)).

  In addition, the interlock metal fitting 6 is provided with a claw metal fitting 63 that can move in the direction of the plate insertion hole 61 (the left-right direction in FIG. 5B) when the lock plate 9 is engaged and disengaged. The claw fitting 63 includes a rectangular plate-like portion 63p and projecting pieces 63u and 63d that protrude in opposite directions from the opposite ends of the plate-like portion 63p in a direction perpendicular to the plate-like portion 63p. One of the two projecting pieces (the upper projecting piece 63u in the upper part of the drawing) is inserted into the lateral hole 6h penetrating from the space where the claw fitting 63 is placed into the unlocking hole 67, and the claw fitting 63 is moved along with the movement. Enter and exit the unlock hole 67. Further, it has a claw body 63b that protrudes from the center of the plate-like portion 63p to the opposite side to the protruding pieces 63u, 63d. A compression spring (fourth elastic body) 63s is provided at the end of the claw body 63b, and the claw fitting 63 is pressed toward the opening of the plate insertion hole 61. The claw fitting 63 and the compression spring 63s are, as will be described in detail later, a second key operation restriction mechanism that restricts removal of the key fitting 7 when the lock plate 9 and the interlock fitting 6 are disengaged. It is.

  Here, in this figure where the interlock metal fitting 6 and the lock plate 9 are in an engaged state, the lock plate 9 is inserted into the plate insertion hole 61 of the interlock metal fitting 6, and the tip of the lock plate 9 is the nail metal fitting. The center of 63 plate-like parts 63p is pressed. That is, the claw fitting 63 is pressed, and the upper protruding piece 63u above the claw fitting 63 is retracted from the lock release hole 67.

[Installation procedure for grounding tools]
When grounding work is performed using the grounding tool of the present invention, the following procedures [1] to [6] are followed.
[1] Fix the grounding bracket to the grounding target
[2] Remove the key bracket from the ground bracket
[3] Insert the key bracket into the interlock bracket, and release the engagement between the lock plate and the interlock bracket.
[4] Extending the insulation rod
[5] Hold the conductive member with the gripping bracket
[6] Work on an overhead power transmission line Note that the grounding tool of the present invention has a mutual locking mechanism using key fittings that restricts the operation of each component of the grounding tool. Can not be done.

[1] Fix the grounding bracket to the grounding target. Fix the grounding bracket with the key bracket inserted to the grounding target. As already described with reference to FIG. 3, the key fitting 7 cannot be removed from the earth fitting 5 before being fixed to the grounding object. For this reason, the insulating rod cannot be extended by inserting the key fitting into the interlock fitting. That is, at the present time, the operation that can be performed by the operator can be limited to the attachment of the grounding metal.

  When connecting the grounding metal 5 to the grounding object, first, the grounding object is arranged between the clamping plate 53 and the pressing piece 52t of the thumbscrew 52. The grounding object is, for example, a steel frame of a steel tower provided with an overhead power transmission line.

  Next, as shown in FIG. 4 (A), the thumbscrew 52 is rotated to feed the thumbscrew 52 downward in the figure. The pressing piece 52t provided at the tip of the sent out thumbscrew 52 presses the clamping plate 53 via the grounding object ob and moves the clamping plate 53 downward. When the clamping plate 53 moves downward, the grounding object ob sandwiched between the pressing piece 52t of the thumbscrew 52 and the clamping plate 53 by the elasticity of the compression spring 53s arranged between the lower piece 511 and the clamping plate 53 Is tightened, that is, the ground metal fitting 5 is fixed to the non-grounded object ob. At this time, the pin metal fitting 56 fixed to the holding plate 53 moves downward together with the holding plate 53, and the pencil down portion 56t is detached from the pin groove 55g of the pin metal 55. Therefore, by pulling the pin fitting 55, if the pin fitting 55 can be pulled, it can be seen that the grounding object ob is sufficiently tightened to fix the grounding metal part 5 to the grounding object ob.

[2] Remove the key bracket from the ground bracket. Pulling the pin bracket 55 that has been fixed by the pin bracket locking bracket 56 from the state in which the object to be grounded is tightened with the ground bracket 5, this time, as shown in FIG. As shown, the fixing of the key fitting 7 by the pin fitting 55 is released. The key fitting 7 that has been released can be pushed out of the locking piece 54 on which the elastic force of the compression spring 54s is applied, and can be removed from the key fitting insertion hole 57. When pulling the pin fitting 55, it may be confirmed that the cutout surface 52p of the cutout surface 52p is exposed from the upper piece 510 and that the cutout surface 52p faces the key fitting insertion hole 57. preferable. If a marker is provided on the head of the thumbscrew 52, it may be confirmed that the notch surface 52p faces the key fitting insertion hole 57 from the position of the marker.

  On the other hand, the detent piece 54 that has pushed out the key fitting 7 advances to the large diameter portion 57w side of the key fitting insertion hole 57. At this time, the main body piece 54b of the rotation stopper piece 54 is disposed at a position facing the notch surface 52p of the shaft portion 52a. When trying to rotate the thumbscrew 52 in this state, the notch surface 52p of the shaft portion 52a comes into contact with the side surface (contact surface) of the detent piece 54, so the thumbscrew 52 cannot be rotated. Therefore, the ground metal 5 from which the key metal 7 has been removed cannot be removed from the ground object ob unless the key metal 7 is inserted into the key metal insertion hole 57 again.

  In this procedure [2], the key fitting 7 may be removed with the notch surface 52p not necessarily facing the key fitting insertion hole 57. When the key fitting 7 is removed with the cut-out surface 52p not facing the key fitting insertion hole 57, the non-rotating piece 54 pressed by the compression spring 54s is at the cut-out surface 52p of the shaft portion 52a. Touch the surface that does not exist. When the thumbscrew 52 is rotated from this state, the notch surface 52p faces the key fitting insertion hole 57, and at the same time, the detent piece 54 advances to a position facing the notch surface 52p, and the thumbscrew 52 is rotated. Suppress. That is, even if the cut-out surface 52p does not face the key fitting insertion hole 57, the thumbscrew 52 cannot be rotated more than once. Therefore, the direction in which the cut-out surface 52p faces is not particularly limited as long as the ground metal fitting 5 does not come off from the object to be grounded by the rotation of the thumbscrew 52 less than one rotation.

[3] Insert the key fitting into the interlock fitting, and release the engagement between the lock plate and the interlock fitting. Next, insert the key fitting into the lock release hole of the interlock fitting. As shown in FIG. 6, when the key fitting 7 is inserted into the unlocking hole 67, the tip end portion 7 t of the key fitting 7 presses the lock piece tip end portion 62 t of the lock piece 62. The front end portion 62t of the pressed lock piece is withdrawn from the retaining hole 9h of the lock plate 9, and the distal end portion 7t of the key fitting 7 advances into the retaining hole 9h. Here, since the outer diameter of the tip 7t of the key fitting 7 is smaller than the width of the slit 9s of the lock plate 9, the lock plate 9 pressed against the claw fitting 63 is pushed out from the plate insertion hole 61. The claw fitting 63 that has pushed out the lock plate 9 moves to the right in FIG. 6, and the upper protruding piece 63u of the claw fitting 63 advances into the large diameter portion 67w of the unlocking hole. At this time, the upper projecting piece 63u protrudes to the position of the groove 7g of the key fitting 7, and when trying to remove the key fitting 7 from the unlocking hole 67, the flange 7f of the key fitting 7 is abutted and stopped. Do not remove the bracket 7 from the unlocking hole 67. That is, even if the tip 7t of the key fitting 7 is pressed against the tip 62t of the lock piece 62, the key fitting 7 does not come out of the lock release hole 67.

[4] Extending the Insulating Bar By releasing the engagement between the lock plate 9 and the interlock metal fitting 6, the insulating bar 2 can be extended. As already described with reference to FIG. 2 (A), the insulating rod 2 is a member in which a plurality of cylindrical members 21 to 24 are configured in a nested manner, and can be extended by extending the nested members 22 to 24. . The worker who performs the grounding operation operates the tubular member 21 located on the outermost periphery side among the nested tubular members. Here, interlocking metal fittings 6e (see Fig. 5 and Fig. 6) are fixed to the stone hammer 28 and the insulating metal fittings 6 are not obstructed when operating the insulation rod 2. To do.

[5] Grip the conductive member with the gripping bracket. Operate the grounding tool with the insulating rod extended, and grip the conductive member with the gripping bracket provided at the tip of the insulating rod. At this time, the grounding fitting is already connected to the grounding object, and even if a current flows through the gripping metal, current can be released from the gripping metal to the grounding object via the grounding wire and the grounding metal. When gripping the conductive member with the gripping bracket, the conductive member is guided to the opening of the gripping bracket by hooking the gripping bracket on the conductive member. As shown in FIG. 1, the gripping fitting 3 of this example is attached to the tip of the insulating rod 2 via a universal joint j, and can be bent within the movable range of the joint j.

[6] Work on the overhead power transmission line As the grounding work has been properly completed by the operations in [1] to [5] above, perform maintenance work on the grounded power transmission line safely. be able to.

[Removal procedure of grounding tool]
After the work on the overhead power transmission line is completed, the work for removing the grounding tool is performed according to the following procedure.
[7] Remove the gripping bracket from the conductive member
[8] Shorten the insulation rod and engage the lock plate with the interlock bracket
[9] Remove the key fitting from the interlock fitting.
[10] Insert the key bracket into the ground bracket and remove the ground bracket from the grounding object. Note that the grounding tool cannot be removed except by the above procedure, depending on the configuration of the grounding tool already described.

[7] Remove the gripping bracket from the conductive member. When grounding, the key bracket 7 is inserted into the interlock bracket 6 as shown in FIG. 6, and the key bracket 7 is removed from the interlock bracket 6. I can't. That is, since the key fitting 7 cannot be inserted into the ground metal fitting 5, as shown in FIG. 4B, the ground metal fitting 5 cannot be removed from the ground object ob by rotating the thumbscrew 52. Therefore, the operation that can be performed by the operator at this time can be limited to the operation of removing the gripping bracket from the conductive member. Since the state in which the key fitting is not inserted into the ground fitting can be visually confirmed, it is possible to prevent the operator from touching the ground fitting in an attempt to remove the ground fitting from the grounding object.

[8] Shorten the insulation rod and engage the lock plate with the interlock bracket Even after the grip bracket is removed from the conductive member, the key bracket cannot be removed from the interlock bracket, allowing the operator Can be limited to the operation of shortening the insulating rod.

[9] Pulling out the key fitting from the interlock fitting If the insulating rod is shortened, the interlock fitting that has been limited in the range that can be moved by the locking rope can be engaged with the lock plate. Therefore, the lock plate is inserted into the plate insertion hole of the interlock metal fitting.

  As shown in FIG. 5, the inserted lock plate 9 pushes the claw fitting 63 into the back at the tip. At this time, the upper protruding piece 63u of the claw fitting 63 that has advanced into the unlocking hole 67 retreats from the unlocking hole 67, so that the engagement of the key fitting is released. The key fitting whose engagement is released is pressed by the lock piece 62 and pushed out from the lock release hole 67. Then, the tip 62t of the lock piece 62 that has pushed out the key fitting advances into the retaining hole 9h of the lock plate 9, and the lock plate 9 and the interlock fitting 6 are engaged.

[10] Insert the key bracket into the ground bracket and remove the ground bracket from the grounding object. Finally, insert the key bracket into the key bracket insertion hole of the grounding bracket and remove the grounding bracket from the grounding object. As shown in FIGS. 3 (A) and 3 (B), the distal end portion 7t of the inserted key fitting 7 presses the distal end piece 54t of the anti-rotation piece 54, and the anti-rotation piece 54 is inserted into the key fitting insertion hole 57. Push it into the back (bottom 57b side). The main body piece 54b of the detent piece 54 that has been pushed in moves to a position that does not face the notch surface 52p of the shaft portion 52a of the thumbscrew 52. For this reason, the notch surface 52p of the shaft portion 52a is not held against the side surface of the main body piece 54b, so that the thumbscrew 52 can be rotated.

  After inserting the key fitting 7, push the pin fitting 55 so that the pin tip 55t of the pin fitting 55 protrudes into the large diameter part 57w of the key fitting insertion hole 57, and the pin tip 55t is the flange part of the key fitting 7. Try to stop 7f. With this pin fitting 55, it is possible to prevent the key fitting 7 from being removed from the key fitting insertion hole 57 even when the key fitting 7 is pressed against the rotation stopper piece 54.

  From the state in which the pin fitting 55 is pushed in, the thumbscrew 52 is rotated in the direction of loosening. As the thumbscrew 52 is loosened and the object to be grounded is loosened, the holding plate 53 is directed toward the upper piece 510 by the elasticity of the compression spring 53s disposed between the lower piece 511 and the holding plate 53 (FIG. 3). (Above (A) and (B)). At this time, the pin metal fitting 56 advances toward the pin metal 55 as the holding plate 53 moves. When the clamping plate 53 comes into contact with the side piece 512 of the ground metal fitting 5, the pencil down part 56t of the pin metal fitting 56 is fitted into the pin groove 55g of the pin metal 55, and the pin metal 55 is pulled. Do not. That is, the key fitting 7 cannot be removed from the key fitting insertion hole 57 of the ground fitting 5.

  As described above, since the grounding tool of the present invention has the attachment and removal procedures limited to proper procedures, the attachment and removal procedures are not mistaken. Therefore, an electric shock accident of the operator can be prevented.

<Modification>
A grounding tool configured to feed out the locking cable and the fall prevention cable from the automatic winding device will be described below. In addition, since the member same as above-described embodiment is used except the structure demonstrated below, the same code | symbol is attached | subjected about the overlapping structure and description is abbreviate | omitted.

  FIG. 7 is a schematic configuration diagram of the grounding tool of this example. However, in FIG. 7, the holding metal fitting fixed to the tip of the insulating rod is omitted.

  As shown in the drawing, in the grounding tool of this example, two winding devices 70 and 80 are fixed to a stone striking metal fitting 28 provided at the rear end of the insulating rod 2. A fall prevention cable 79 is fed out from the winding device 70, and a locking cable 8 is fed out from the winding device 80.

  The end of the fall prevention rope 79 that is fed out from the winding device 70 is fixed to the key fitting 7. When the key fitting 7 is not inserted into the ground fitting or the interlock fitting 6, the fall prevention rope 79 is It is wound up by the winding device 70. Therefore, the key fitting 7 is always at the rear end of the insulating rod 2 when not inserted into another fitting, that is, at the operator's hand, so there is no risk of losing the key fitting 7. This is convenient when the key fitting 7 is used next time.

  On the other hand, the locking cable 8 fed out from the winding device 80 is folded back by the ring-shaped connecting metal fitting (see reference numeral 64 in FIG. 5) of the interlock metal fitting 6, and the folded length is fixed by the length adjusting member 85. Yes. Here, the locking cable 8 is in a state of being fully drawn out in the state shown in the drawing and cannot be extended any more, so the interlock metal fitting 6 and the engagement metal fitting 9 are engaged. As long as it is, the insulating rod 2 cannot be extended. Since the interlock fitting 6 released from the engagement by the winding device 80 is automatically arranged at the rear end of the insulating rod 2, it does not interfere with the work.

  Since the length of the locking cord 8 can be adjusted as appropriate by the length adjusting member 85, the winding device 80 uses a general-purpose winding device in which the length of the cord wound on the device is predetermined. it can. In addition, by adjusting the folding length of the locking cord 8, the locking cord 8 is restricted to extend so that the length of the insulating rod 2 is limited, and the length of the locking cord 8 has a play that does not interfere with the gripping of the insulating rod 2. good.

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

FIG. 1 is a schematic configuration diagram of the grounding tool of the present invention, and the inside of a circle in the drawing is a partially enlarged view in the vicinity of an interlock fitting. Fig. 2 (A) is a schematic configuration diagram of an insulating rod, Fig. 2 (B) is a schematic configuration diagram of a gripping bracket, Fig. 2 (C) is a schematic configuration diagram of a key bracket, and Fig. 2 (D) is a lock The schematic block diagram of a plate is shown. FIG. 3 is a partial cross-sectional view of the ground metal fitting, where (A) is a front view, (B) is a top view, and (C) is a side view. Fig. 4 (A) is an explanatory view of the state of the grounding bracket when the grounding object is tightened with the grounding bracket as viewed from the front, and Fig. 4 (B) is a further illustration of the key bracket from the state of Fig. 4 (A). It is explanatory drawing which looked at the internal state when removing from the upper surface. FIG. 5A is a top view of the interlock metal fitting, and FIG. 5B is a partial cross-sectional view of the interlock metal fitting when viewed from the front. FIG. 6 is an explanatory diagram showing an internal state of the interlock fitting when the key fitting is inserted into the interlock fitting. FIG. 7 is a schematic configuration diagram of a grounding tool shown in a modified example. However, the gripping bracket is omitted. FIG. 8 is a schematic configuration diagram of a conventional grounding tool.

Explanation of symbols

1 Grounding tool ob Grounding object
2 Insulating rod 21, 22, 23, 24 Cylindrical member 2g Ring groove 28
3 Grip bracket 31 Fixed grip piece 32 Movable grip piece 33 Shaft j joint
311 Grounding wire mounting base 312 Grounding wire outlet
4 Ground wire
5 Grounding bracket
51 Metal fitting 510 Upper piece 511 Lower piece 512 Side piece 513 Back piece 514 Connection
52 Thumbscrew 52a Shaft 52t Pressing piece 52p Notch surface
52s compression spring 52f flange
53 Holding plate 531 Positioning pin 53s Compression spring n Nut
54 Non-rotating piece 54b Body piece 54t Tip piece 54s Compression spring
55 Pin bracket 55g Pin groove 55f Pin flange 55t Pin tip
56 pin bracket locking bracket 56t pencil down part
57 Key fitting insertion hole 57w Large diameter part 57n Small diameter part 57b Bottom
6 Interlock bracket
61 Plate insertion hole 6h Horizontal hole
62 Lock piece 62b Lock piece body 62t Lock piece tip 62s Compression spring
63 Claw bracket 63b Claw body 63p Plate
63u Upper protrusion 63d Lower protrusion 63s Compression spring
64 Connection bracket 64e Eggplant type ring
67 Unlocking hole 67w Large diameter part 67n Small diameter part 67vn Narrow part 67b Bottom part
7 Key bracket 7b Body 7g Groove 7f Flange 7t Tip
7r ring 70 Winding device 79 Fall prevention cord
8 Locking cord 80 Winding device 85 Length adjusting member
9 Lock plate 9h Retaining hole 9s Slit 9r Lock ring
100 Grounding tool 200 Conductive member
101 Insulating rod 102 Grip bracket 103 Ground wire 104 Ground bracket

Claims (13)

Telescopic insulation rod,
A gripping bracket that is attached to the tip of the insulating rod and grips the conductive member;
A grounding tool that has a grounding metal connected to the gripping metal via a grounding wire and releases the current flowing through the conductive member to the ground,
The grounding tool
An interlock mechanism that limits the extension motion of the insulation rod;
It is equipped with a key bracket that can be attached to and detached from the ground bracket and the interlock mechanism.
The grounding bracket includes a tightening mechanism for tightening the grounding object, a first key bracket mounting portion for attaching the key bracket, a tightening operation locking mechanism for restricting the tightening operation of the tightening mechanism, and a key from the first key bracket mounting portion. A first key operation restriction mechanism for restricting the attachment / detachment of the metal fitting,
The tightening operation lock mechanism enables the tightening operation by the tightening mechanism when the key bracket is attached to the first key bracket mounting section.
The first key operation restriction mechanism is configured so that the key fitting can be removed from the first key fitting mounting portion when the tightening amount of the tightening mechanism becomes larger than a predetermined amount.
The interlock mechanism has a second key bracket mounting portion for mounting the key bracket,
A grounding tool configured to be in an unlocked state in which an insulating rod can be extended by attaching the key fitting to the second key fitting mounting portion. The interlock mechanism further includes a second key operation restriction mechanism for restricting the attachment / detachment of the key fitting from the second key fitting mounting portion,
The grounding tool according to claim 1, wherein the second key operation restriction mechanism is configured such that the key fitting cannot be removed from the second key fitting mounting portion when in the unlocked state. A over the scan bracket is provided with a grounding bracket body,
The first key metal mounting portion provided on the ground fitting body, the grounding device of claim 1 or 2, characterized in that the key bracket insertion hole capable Insert the key fitting. The key bracket is
A key body, and a step formed at an intermediate portion of the key body,
The grounding bracket tightening mechanism is
A screw shaft that can be moved forward and backward with respect to the earth metal fitting body so that a part of the peripheral surface is exposed in the key metal fitting insertion hole, and presses the grounding object at the tip portion;
A clamping piece that is arranged at a position facing the tip portion of the screw shaft across the grounding object and is supported by the grounding metal body so as to be movable in the direction in which the grounding object is pressed;
A first elastic body that urges the clamping piece in a direction to tighten a grounding object sandwiched between the clamping piece and the screw shaft;
The tightening operation lock mechanism
A notch surface formed by notching a part of the peripheral surface of the screw shaft;
A detent member that is disposed inside the key fitting insertion hole and has a contact surface that limits rotation of the screw shaft by contacting the notch surface;
A second elastic body for biasing the rotation preventing member in the opening direction of the key fitting insertion hole,
The anti-rotation member is configured to move to a position where the contact surface is not in contact with the notch surface by being pressed by the key metal when the key metal is inserted into the key metal insertion hole.
The first key operation restriction mechanism is
Attached to the ground fitting body so as to be retractable inside the key bracket insertion hole, the pin fitting key bracket by engaging the stepped portion of the key fitting is fixed so as not escape key fitting insertion holes or al When,
One end is fixed to the clamping piece so that it can advance and retreat with respect to the pin fitting, and the other end has a pin fitting locking fitting that fixes the pin fitting by engaging with the pin fitting,
The grounding tool according to claim 3, wherein the pinching piece is configured to be disengaged from the pin fitting by moving a predetermined amount of the pinching piece.   The grounding tool according to claim 4, further comprising a pressing piece that is loosely fitted to a tip portion of the screw shaft and presses the grounding object without co-rotating with the rotation of the screw shaft.   The grounding tool according to claim 4 or 5, wherein a marker indicating a direction in which the cut-out surface faces is provided at a position protruding from the ground metal fitting in the screw shaft. Interlock mechanism,
An engagement fitting fixed to the insulating rod;
An interlock fitting that has a lock release hole that is a second key fitting attachment portion into which the key fitting can be inserted, and engages with the engagement fitting;
The insulation rod and the interlock metal fitting are connected, and the engagement rod and the interlock metal fitting are provided with a locking cord for maintaining the contracted state when the engagement metal fitting and the interlock metal fitting are engaged.
By inserting the key fitting into the lock release holes, to any one of claims 1 to 6, characterized in that it is configured to be able to release the engagement between the engagement alloy tool and interlock bracket The grounding tool described . The engagement bracket is
A block-shaped body;
A retaining hole penetrating the block-shaped body,
One end communicates with the retaining hole, the other end opens to the outside of the block-shaped body, and has a slit with a width smaller than the diameter of the retaining hole,
The key bracket is
The key body,
A step provided in the middle of the key body;
Protruding at the tip of the key body, and having a tip having a diameter smaller than the width of the slit,
Interlock metal fittings
An engagement bracket insertion hole that can be inserted into the lock release hole,
A lock piece that is disposed at an opposite position across the opening of the lock release hole and the engagement metal fitting insertion hole, and is movable in the axial direction of the lock release hole in accordance with insertion / removal of the key metal,
A third elastic body that urges the lock piece toward the opening of the unlocking hole, and the lock piece is a tip piece having a diameter smaller than the inner diameter of the retaining hole and larger than the width of the slit. Have
8. The grounding tool according to claim 7, wherein the lock piece is retracted by inserting the key fitting into the unlocking hole so that the engagement fitting is detachable from the interlock fitting. And a key operation restriction mechanism for restricting removal of the key fitting from the unlocking hole when the engagement between the engagement fitting and the interlock fitting is released,
The key operation restriction mechanism
A claw fitting that is arranged in the back of the engagement fitting insertion hole and can be advanced and retracted in a direction crossing the axial direction of the unlocking hole;
A fourth elastic body for biasing the claw fitting in the opening direction of the engagement fitting insertion hole,
By releasing the engagement between the engagement metal fitting and the interlock metal fitting, a part of the claw metal fitting advances into the lock release hole and engages with the stepped portion of the key metal fitting so that the key metal fitting does not come out of the lock release hole. And
The key bracket can be removed from the lock release hole by inserting the engagement bracket into the engagement bracket insertion hole and pressing the claw bracket so that a part of the claw bracket is withdrawn from the lock release hole. The grounding tool according to claim 8.   The grounding tool according to any one of claims 7 to 9, further comprising a length adjusting member that adjusts the length of the locking cord by folding and binding the locking cord.   The insulating rod is fixed to an end portion opposite to the holding metal fitting, and includes a winding device that automatically winds up the locking cord. Grounding tool. A fall-preventing cord that connects the key bracket to the insulation rod;
The grounding tool according to any one of claims 1 to 11, further comprising a winding device that automatically winds the fall prevention cord.   The grounding tool according to any one of claims 1 to 12, wherein the key fitting is colored.

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