JPH0321164Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a pulling eye that is attached to the end of a cable when it is drawn into a pipe or the like.

(Prior Art) When pulling a power cable into a pipe or the like, a pulling eye is attached to the end of the cable. There has been a search for a structure that reliably connects the pulling eye to the cable so that it will not fall off even when a large tensile force is applied to the cable, and pulling eyes with various structures have been devised in the past.

FIG. 4 shows a conventional example of a structure in which a pulling eye is connected to the end of a cable.

A compression sleeve 2, which has a substantially hollow cylindrical shape and has a male threaded portion 21 with a slightly smaller diameter on the closed end side, is compressed and fixed to the exposed conductor end 11 of the cable 1 exposed by the pencilling process. . A waterproof tape is layered around the compression sleeve 2 at the end of the cable 1 to form a waterproof tape layer 14, and a cover tape 15 is wound on the outermost side of the waterproof tape layer 14. Note that numerals 12 and 13 indicate an insulating layer and an anticorrosion layer of the cable 1, respectively.

The cable connection side of the pulling eye 3 is a hollow cylindrical cable insertion tube portion 31, and a female thread portion 32 is formed at the bottom of the cable insertion tube portion 31, that is, on the eye 33 side.

When connecting the pulling eye 3 to the cable 1, the female threaded portion 32 is screwed into the male threaded portion 21 of the compression sleeve 2. At this time, the waterproof portion of the end of the cable 1 is accommodated inside the cable insertion tube 31. However, in the actual connection work, conventionally the cable 1 is connected in advance as shown in the same figure.
Pulling eye 3 on the alignment mark M on the
Screw in the pulling eye until the ends of the cable insertion tube 31 match, and then tighten the fixing screw 10 at that position.
1 is tightened to the male threaded portion 21 so as to stand upright.

(Problems to be solved by the invention) In the conventional connection structure, the pulling eye 3
A mark M, which is an indicator of the screwing depth of Errors are likely to occur because the measurement is done indirectly or by matching the actual item, and the mark M is written on the rubber or synthetic resin surface, and the edge of the cable insertion tube 31 that is to be matched with the mark M is Since these are separated in the radial direction, there is a risk that a considerable error may occur depending on the direction of the operator's line of sight both when marking marks and when aligning marks. 32 and the male threaded portion 21 of the compression sleeve 2 became insufficient, and there was a risk that the pulling eye 3 would fall off from the cable end.

(Means for solving the problem) This invention was made to solve the above-mentioned problem, and specifies the male threaded part of the compression sleeve fixed to the cable and the female threaded part of the pulling eye. The main idea is to have a pulling eye that has a sufficient threading length to ensure the threaded state.Specifically, it is a pulling eye that has a sufficient threading length to ensure that the threaded state is achieved. In a pulling eye having a female threaded part that is screwed into a male threaded part, a through hole is bored in the meat part of the pulling eye from the bottom of the female threaded part to the tip end surface of the eye in parallel with the cable axis. A detection pin is slidably inserted in the longitudinal direction into the through hole, and the detection pin is biased toward the cable end side by a spring, and the female threaded portion is screwed into the male thread portion by a predetermined amount. In this case, the tip of the detection pin is exposed from the eye tip surface of the pulling eye.

(Function) When screwing the male threaded part of the compression sleeve into the female threaded part of the pulling eye, the detection pin is pushed by the tip of the compression sleeve and moves in the axial direction inside the through hole. When the female thread part is screwed in to the specified screw length, the tip of the detection pin will be exposed from the end surface of the eye of the pulling eye, allowing the operator to know that the pulling eye has been screwed in by the specified amount. This will be confirmed later. In other words, it is possible to easily and reliably perform a connection operation in which the pulling eye is screwed into the compression sleeve with a specified screwing length and the pulling eye is attached to the cable end with sufficient strength.

(Embodiment) An embodiment of this invention will be described with reference to FIGS. 1 to 3.

As shown in the figure, the pulling eye 3 of this invention has a small-diameter through hole extending parallel to the cable axis from the bottom 37 of the female threaded portion 32 screwed into the male threaded portion 21 of the compression sleeve 2 to the end surface 38 of the eye. 34
is bored in the flesh part, and a part of the through hole 34 on the female threaded part 32 side is a push spring storage part 35 having a slightly larger diameter.

The detection pin 8 is slidably inserted into the through hole 34 in its longitudinal direction. This detection pin 8 has a spring seat plate 82 with a slightly large diameter in its center, and both ends thereof are a detection part 81 and a pressing part 83. The portion 32 is made to protrude toward the cable insertion tube portion 31 by a length L, and at this time, the tip of the detection portion 81 is retracted from the eye tip surface 38 in the through hole 34 by the same length l, and A spring 9 is inserted through the detection portion 81 so as to bias the detection pin 8 toward the exposed conductor end portion 11 of the cable 1 . However, the length L(l)
is the specified threading length between the male threaded portion 21 of the compression sleeve 2 and the female threaded portion 32 of the pulling eye 3, that is, the screwing depth that allows sufficient connection strength to be maintained between the two. It is something. In addition, in FIG. 1, the reference numeral 36 indicates the fixing screw 7.
(See Figure 2) Shows screw holes for mounting.
When the pulling eye 3 having the above structure is screwed into the compression sleeve 2 fixed to the exposed conductor end 11 of the cable 1 as shown in FIG.
The pressing part 83 is pushed to the left in the figure by the end surface of the compression sleeve 2 against the spring force of the spring 9, and the pulling eye 3 is pushed to the left in the drawing to reach the specified screw length L.
When the detection part 8 of this detection pin 8 is screwed in
1 is exposed on the eye tip surface 38 of the pooling eye 3, and this state can be easily recognized from the outside.

This state indicates that the pulling eye 3 is connected to the compression sleeve 2 with sufficient connection strength, and at this time, the fixing screw 7 is tightened against the male threaded portion 21 to prevent the loosening rotation of the pulling eye. All you have to do is fix it to prevent it.

(Effect of the invention) According to this invention, by exposing the tip of the detection pin to the end surface of the eye, the female thread of the pulling eye and the male thread of the compression sleeve are screwed together with a specified thread length. Since the matching state can be confirmed, the pulling eye can be easily and reliably connected to the cable end.

[Brief explanation of the drawing]

Fig. 1 is a partially cut-away side view showing a pulling eye according to an embodiment of the invention, Fig. 2 is a partially cut-away side view showing the pulling eye of Fig. 1 connected to the tip of a cable, and Fig. 3 is a partially cut-away side view showing the pulling eye of Fig. FIG. 2 is an end view seen from the pulling eye side, and FIG. 4 is a partially cutaway side view showing a conventional connection structure between the pulling eye and the cable. 1...Cable, 11...Exposed conductor end, 2...
...Compression sleeve, 21...Male thread, 3...Pulling eye, 32...Female thread, 34...Through hole, 37...Bottom, 38...Eye end surface, 8...
Detection pin, 9...spring.

Claims (1)

[Scope of utility model registration request] In a pulling eye 3 having a female threaded part 32 that is screwed into the male threaded part 21 at the tip of the compression sleeve 2 fixed to the exposed conductor end 11 of the cable 1, a female threaded part is attached to the flesh part of the pulling eye 3. 3
A through hole 34 extending from the bottom 37 of the eye to the end surface 38 of the eye is bored parallel to the cable axis, and a detection pin 8 is inserted into the through hole 34 so as to be slidable in the longitudinal direction. is urged toward the end of the cable by the spring 9, and when the female threaded portion 32 is screwed into the male threaded portion 21 by a predetermined amount, the tip of the detection pin 8 touches the pulling eye 3. A pooling eye configured to be exposed from an eye tip surface 38.