JP2016116416A - Extension clamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extension clamp which facilitates wire gripping work and is unlikely to be removed even if impulse is applied thereto.SOLUTION: An extension clamp 1 is configured by combining a main body 2 and a pressing member 6 which are movable relatively to each other. In the main body 2, a groove 3 of which the cross section is U-shaped is formed so as to penetrate in a direction of insertion. The pressing member 6 is disposed while being inserted between the U-shaped grooves 3. In the main body 2, four protruding pins 4 which protrude inside of the U-shaped groove 3 are protrusively provided towards the inside. On an outer side surface of the pressing member 6, on the other hand, a guide groove 6c is formed with which front ends of the protruding pins 4 slide in contact. In the state where the main body 2 and the pressing member 6 are combined, the front ends of the protruding pins 4 are accommodated within the guide groove 6c. When a core wire of a cable is inserted from an inlet 1a and a messenger wire or the like coupled to a protruding piece 6d of the pressing member 6 protruding at a deep side is pulled, the protruding pins 4 are guided by the guide groove 6c and the pressing member 6 is moved to a side of a bottom 3a of the groove 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wire extension clamp that grips an end portion of a drawn-in electric wire when an electric wire such as an overhead power transmission line is extended.

  In the extension work of overhead transmission lines, extension clamps are used to grab and pull the ends of the wires. FIG. 5 shows a state of conventional wire extension work. As shown in FIG. 5, the tip end of the newly drawn electric wire 50 is held by the wire extension clamp 101. A messenger wire 104 is connected to the wire extension clamp 101, and the electric wire 50 can be drawn by pulling the messenger wire 104. Each of the steel towers 102 to be subjected to the overhead wire work is provided with a gold wheel 103, and the messenger wire 104, the wire extension clamp 101 and the electric wire 50 are guided by the gold wheel 103.

  If the wire clamp 101 is not shaped so that it can pass through the gold wheel 103 smoothly, it will be caught and the operation will be interrupted. Moreover, if it is not a structure strong against an impact, if the electric wire 50 comes off from the extension clamp 101 and the work is interrupted, and the removed electric wire falls, there is a danger to the worker on the ground.

  Therefore, it is generally desirable for the wire clamp to have a slim outer shape so that the electric wire can be firmly held and the resistance can be reduced.

  Conventionally, the structure of the wire clamp which considered said requirements is considered. Specifically, for example, there is a wire clamp 101 as shown in FIG. In the wire clamp 101 of FIG. 6, the wedge portion 105 is inserted between the core wire 50 a and the outer layer wire 50 b of the electric wire 50. In this state, the sleeve 106 is compressed from the outside, and the sleeve 106 that has been plastically deformed thereby is crimped integrally with the uneven portion 107 a of the steel clevis 107 connected to the messenger wire 104. Thus, the electric wire 50 is firmly connected to the messenger wire 104 by the wire extension clamp 101. Patent Document 1 describes the wire drawing work and wire clamp as described above.

  In addition to the above, a configuration in which a wire is clamped by inserting a wedge member between the sleeve and the wire is also known (see Patent Document 2).

Japanese Utility Model Publication No. 61-068614 Japanese Utility Model Publication No. 61-157903

  By the way, the core wire of the electric wire is generally a stranded wire. Therefore, when the core wire made of the stranded wire is cut with an electric wire cutter or the like, the cut ends are scattered and spread. For this reason, when using a wedge-shaped clamp as described in Patent Document 2 above, the diameter of the core wire is different between the widened cut end and the vicinity thereof, and therefore it cannot be tightened with equal pressure. .

That is, since the pressure is concentrated on the expanded end portion, the clamping pressure is biased. Moreover, it is difficult to judge the tightening degree by resistance. For this reason, although the resistance is large, a state where the tightening is loose may occur. When the wire drawing work is performed in such a state, loosening occurs due to an impact when the wire drawing clamp comes into contact with the gold wheel or the roller member, and in the worst case, the electric wire may come off.

  Further, as in the example of Patent Document 1, in the configuration in which the wedge portion 105 is inserted between the core wire 50a and the outer layer wire 50b of the electric wire 50 and the sleeve 106 is plastically deformed and fixed from the outside, the wire clamp 101 is connected to the electric wire. When removing 50, it has to cut | disconnect, and an operation | work becomes complicated.

  It should be noted that tools of the type that clamp the electric wire from the opposite direction, such as a holding clamp or a gripper that temporarily fixes the electric wire, can be easily clamped, so the working time can be shortened. Is possible. However, since there are many large-sized structures, such as those using a cam mechanism or a screw fastening mechanism, it is not suitable for smoothly passing a gold wheel or a roller member.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wire clamp that can be easily gripped and does not easily come off even under impact.

  In order to achieve the above-mentioned object, the wire extension clamp of the present invention has a U-shaped groove into which a core wire of an electric wire is inserted, and the inner side from the inner side facing each other across the bottom in the groove. A pressing groove for pressing the core wire is formed between the main body on which the protruding pin protrudes toward the bottom and the bottom portion, and the protruding pin slides on the outer surface facing the inner surface. The guide groove to be guided is provided with a presser member formed so as to be inclined so that the back side is closer to the presser groove than the entrance direction entrance side of the core wire, and the bottom part has the back side on the entrance side It is characterized by being expanded from the side.

  Further, in the wire clamp according to the present invention, the pressing member has a protruding piece protruding to the back side from the main body, and the core wire is sandwiched between the bottom portion and the pressing groove on the protruding piece. In this embodiment, a loosening-preventing screw that can be screwed back and forth to a position where it can contact the end surface on the back side of the main body is provided.

  As described above, according to the present invention, the guide groove on which the projecting pin of the main body slides is inclined toward the presser groove side on the back side in the insertion direction. For this reason, when a force is applied to pull the main body toward the inlet side and the holding member toward the back side, the presser member moves to the bottom side of the main body due to the reaction from the protruding pin that slides the guide groove toward the inlet side. And the force which pinches | interposes a core wire between the bottom parts of a U-shaped groove | channel generate | occur | produces.

  Moreover, since the back side of the bottom part is expanded more than the entrance side, even if it is a case where the cut end of a core wire spreads and spreads, it can arrange | position by suppressing the float on the cut end side. Thereby, the presser groove can abut against the core wire evenly. That is, since the pressure applied by the pressing member is evenly distributed without being concentrated in a narrow range on the cutting end side, a small force can be effectively applied to stably hold the core wire.

  Further, according to the present invention, in addition to the above effect, when the core wire is clamped and fixed by the main body and the presser member, when the locking screw is advanced until it comes into contact with the end surface on the back side of the main body, the presser member is moved to the main body. Is prevented from moving to the entrance side. Thereby, the clamping state of a core wire is locked and it becomes possible to work safely.

It is a general view by the front view of the wire clamp which concerns on embodiment of this invention. It is an exploded view of the wire clamp of FIG. The use state of the wire clamp of FIG. 1 is shown, (a) is a top view, (b) is an AA sectional view. It is an enlarged view of the edge part of the core wire of the electric wire in the state clamped by the wire extension clamp of FIG. It is the figure shown about the conventional wire drawing construction. It is a figure which shows the conventional wire clamp.

  Hereinafter, a wire clamp according to an embodiment of the present invention will be described with reference to the drawings.

  First, the configuration of the wire clamp will be described with reference to FIGS. FIG. 1 shows a front view of a wire clamp 1 according to the present embodiment. Here, in the direction in which the core of the electric wire is inserted, the right side of FIG. 1 is shown in an arrangement such that the right side is the inlet 1a side and the left side is the back side in the insertion direction. Moreover, FIG. 2 has shown the state which decomposed | disassembled the wire clamp 1 of FIG. In FIG. 2, the inlet 1 a side in the insertion direction in FIG. 1 is shown facing forward.

  As can be seen from the exploded view of FIG. 2, the wire extension clamp 1 is configured by a combination of the main body 2 and the pressing member 6. The main body 2 is formed with a U-shaped groove 3 into which the core of the electric wire is inserted. The bottom 3a of the groove 3 is formed in a concave shape so as to be in contact with one side surface of the core wire.

  Further, two protruding pins 4 are provided on the inner side of the U-shaped groove 3 from the respective inner side surfaces 3b facing each other in parallel with the bottom 3a interposed therebetween.

  On the other hand, the presser member 6 has a presser groove 6 a that presses the core wire at a position facing the bottom 3 a of the groove 3 of the main body 2. In FIG. 2, in order to show the shape of the presser groove 6a, the presser member 6 is shown upside down for convenience. And the inclined guide groove 6c is formed in the outer surface 6b of the both sides on both sides of the pressing groove 6a. When the main body 2 and the pressing member 6 are combined, the guide grooves 6c are in a state in which the tips of the protruding pins 4 are slidably fitted. The pressing member 6 can move relative to the main body 2 in an oblique direction by guiding the protruding pin 4 by the guide groove 6c.

  That is, as shown in FIG. 1, when the pressing member 6 is pulled in the direction of the arrow 20, the pressing groove 6 a of the pressing member 6 is guided to the bottom 3 a of the groove 3 of the main body 2 by the guide of the protruding pin 4 by the guide groove 6 c. It moves to approach. Thereby, a messenger wire (not shown) or the like is connected to the protruding piece 6d of the pressing member 6 protruding to the back side of the main body 2, and when the pressing member 6 is pulled in the direction of the arrow 20, the inserted core wire is the main body 2 Between the bottom 3a of the groove 3 and the pressing groove 6a. This pinching state becomes stronger as the force pulling in the direction of the arrow 20 is larger due to the wedge effect.

  The protrusion 6d of the pressing member 6 is provided with a locking screw 8 that can be screwed back and forth from the back side in the insertion direction toward the inlet side. In the above-described pinched state of the core wire, when the locking screw 8 is protruded toward the inlet side and brought into contact with the end face on the back side of the main body 2, the presser member 6 moved to the back side can be fixed.

  In other words, it is possible to lock the presser member 6 that has moved in the direction in which it presses against the core wire, and to prevent the presser member 6 from floating from the main body 2. Thereby, the grasped electric wire can be stably held.

  As will be described later, in the wire extension clamp 1 of the present embodiment, the bottom 3a of the groove 3 of the main body 2 is expanded on the back side rather than the entrance side.

  Next, the wire clamp 1 in a use state is shown using FIG. FIG. 3 shows a state in which the core wire 50a of the electric wire is inserted, (a) shows a plan view, and (b) shows a cross-sectional view taken along line AA in the plan view of (a).

  As described above, the bottom 3a of the groove 3 of the main body 2 is formed by extending the back side more than the inlet side. For this reason, on the back side, there is a gap G between the end of the inserted core wire 50 a and the bottom 3 a of the groove 3.

  By the way, since the core wire 50a of the electric wire is formed of a stranded wire, when the wire is cut by using an electric wire cutter or the like, the tip ends up being spread apart.

  However, since the back side is expanded as described above, a sufficient space is provided to accommodate the end portion of the core wire 50a that has been spread apart. Thus, in the configuration of the present embodiment, since a part of the bottom portion 3a of the groove 3 is expanded as the escape portion 5 in order to accommodate the scattered end portion, the core wire 50a can be stably held. Is possible. Subsequently, this operation will be described with reference to FIG.

  4 is an enlarged view of the end portion of the core wire of the electric wire in a state of being gripped by the wire extension clamp of FIG. 1, and showing an operation diagram in the state of gripping the core wire 50a of FIG. In the gripping state of the wire clamp 1, the core wire 50 a is press-contacted from two opposite directions as indicated by arrows 21 and 22 in FIG. 4. When the end portion of the core wire 50a is not greatly collapsed, a gap G is formed between the escape portion 5 on the back side of the main body 2 and the core wire 50a, but the expanded region indicated by a one-dot chain line in FIG. In the region on the inlet side of the boundary line L1 of the (escape portion 5), the pressure can be applied to the core wire 50a evenly, so that the gripping state is stabilized.

  In addition, when the end of the core wire 50a is separated by cutting, a part of the core wire 50a is attached to the bottom 3a on the back side as the escape portion 5, so that the presser groove is also provided in the region on the back side from the boundary line L1. The pressure from 6a works effectively.

  In FIG. 4, the position of the lower end of the core wire 50a spreading toward the end side is schematically represented by a one-dot chain line L2. As described above, when it is scattered toward the end portion, the core wire 50a exists so as to be inclined from the boundary line L1 toward the back side. Therefore, a slight catching occurs between the bottom 3a of the groove 3 and the core wire 50a at the boundary position surrounded by the circle C. Thus, even when a force acts in the direction in which the electric wire 50 is pulled out (the direction toward the inlet side), a sufficient frictional force is obtained between the core wire 50a and the bottom portion 3a of the groove 3, so that the core wire 50a can be gripped. The holding state is stable.

  That is, according to the present invention, it is possible to eliminate the adverse effect that pressure is concentrated on a part and the gripping state becomes unstable due to the loose end portion generated when the electric wire is cut. The wedge effect obtained by utilizing the looseness, which is a factor of adverse effects, makes it possible to further stabilize the gripping state.

  For this reason, since it can insert in a main body as it is and can perform a grasping operation | work, without adjusting the edge part of the core wire 50a broken by cutting | disconnection, while aiming at the improvement of work efficiency and the improvement of safety | security. It becomes possible.

In the above-described embodiment, the configuration in which the guide grooves are formed on both sides of the outer surface of the pressing member is shown as an example. Moreover, the structure by which the protrusion pin was provided in each of the inner surface of the groove | channel of a main body was shown as an example. However, the same effect can be obtained if a pair of projecting pins and guide grooves are formed on one of the inner side surfaces of the main body and the outer side surface of the pressing member facing the main body. Further, at least one protruding pin and one guide groove may be formed.

  In the above-described embodiment, the configuration in which the guide grooves are formed on the two outer surfaces of the presser member on the front and back sides is shown as an example, but it may be asymmetrical. For example, a configuration in which two guide grooves are formed on one surface and one guide groove is formed on the other surface may be employed.

  Moreover, in said embodiment, the structure by which the escape part 5 was formed in the bottom part 3a of the U-shaped groove | channel 3 of the main body 2 by providing a level | step difference in the back | inner side was shown as an example. However, it is only necessary that the bottom 3a side of the groove 3 is expanded on the back side. For example, the escape portion may be formed by an inclined surface that gradually expands toward the back side.

DESCRIPTION OF SYMBOLS 1 Wire extension clamp 1a Inlet 2 Main body 3 Groove 3a Bottom part 3b Inner side surface 4 Protruding pin 5 Relief part 6 Pressing member 6a Holding groove 6b Outer side surface 6c Guide groove 6d Protruding piece 8 Loosening prevention screw 50 Electric wire 50a Core C Circle G Gap L1 Boundary Line L2 Dash-dot line

Claims (2)

A main body in which a U-shaped groove into which the core wire of the electric wire is inserted is formed, and a projecting pin protrudes inward from the inner surfaces facing each other parallel to each other across the bottom in the groove;
A pressing groove for pressing the core wire is formed between the bottom portion and a guide groove on which the protruding pin slides and guides on the outer surface facing the inner surface. A presser member formed to be inclined so that the back side is closer to the presser groove than the side,
The wire clamp according to claim 1, wherein the bottom portion is expanded on the back side more than the entrance side. The pressing member has a protruding piece protruding to the back side from the main body,
The protruding piece is provided with a locking screw that can be screwed back and forth to a position where the core wire can be brought into contact with the end surface on the back side in a state where the core wire is sandwiched between the bottom portion and the pressing groove. The wire clamp according to claim 1.