JPH0447683Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a pulling end fastener used when pulling and laying an optical fiber cable.

``Prior Art'' Generally, when an optical fiber cable is pulled by the so-called tip traction method and installed in a conduit, the pulling end of the optical fiber cable is It is necessary to tow the protective sheath and the central reinforcing tension member while they are fixed together.

Conventionally, when pulling an optical fiber cable while fixing its pulling end, a fastener as shown in FIG. 4 has been used. This retainer is constructed by placing a sleeve 31 over the tension member 4 exposed from the optical fiber cable 1 and fixing it by caulking or the like.
2 are fixed together, and the protective sheath 2 peeled off from the pulling end of the optical fiber cable 1 is fixed to the sheath gripper 32. Then, a traction line 7 is connected to the tip of the tension member 4 protruding from the sleeve 31 via a coupler 6, and a connection between the tip of the traction line 7 and the outer surface of the protective sheath 2 of the optical fiber cable 1 is made of polychloride. An eye nut 20 is attached to the tip of the towing line 7 while being covered with a protective pipe 8 made of flexible material such as vinyl.
It is designed to be towed as shown by the arrow.

``Problems to be solved by the invention'' By the way, when the optical fiber cable 1 is pulled by such a fastener and laid in a conduit, if there is a bent part in the middle of the conduit, the curvature However, in the structure shown in FIG. 4, the sleeve 31 and the sheath gripper 32 are rigidly integrated, and the coupler 6 is also of a rigid structure. These sleeves 31
Although the tension member 4 is bent only in the portion between the sleeve 31 and the coupler 6, the length of the tension member 4 in the portion between the sleeve 31 and the coupler 6
If l ₁ is short, there is a problem that it becomes difficult to bend that part and the resistance to traction increases. Therefore, it is necessary to securely fix the tension member 4 in order to withstand the resistance force, and if the tension member 4 is repeatedly bent, excessive stress will be applied to the tension member 4 near the tip of the sleeve 31. Concentration tends to cause breakage, etc. Also, when it is necessary to bend the tension member 4, such as when fixing the tension end of the optical fiber cable 1 to a junction box after it has been inserted into a conduit, the coupler 6, etc. If the length l ₂ of the portion of the tension member 4 that protrudes from the sleeve 31 after being removed is short, it will be difficult to bend and the handling will be poor, as described above. In these cases, the length of each part of the tension member 4
It may be possible to make l ₁ and l ₂ longer, but the longer they are, the longer the retaining tool becomes, which is a problem.

The present invention effectively solves the above-mentioned problems, and aims to provide a fastening device that facilitates the bending of the tension member and improves the workability of pulling, connecting, etc.

"Means for Solving the Problems" In order to achieve such an object, the present invention includes a sheath gripper that grips the protective sheath at the end of the optical fiber cable, and a sheath gripper that grips the protective sheath at the end of the protective sheath in the traction direction. It has a sleeve that is fixedly placed over the tension member, and the tension member is inserted into the sheath gripper at the front end position in the pulling direction with a gap, and when the tension member is pulled, the sleeve is inserted. A ring is provided that comes into contact with the sleeve from a rear position in the traction direction to prevent it from coming off, and at least one of the contact portions between the ring and the sleeve has a spherical surface so that the sleeve can swing against the ring. It is characterized by having a spherical seat that allows the

"Operation" The retaining device of the present invention fixes the sleeve to the tension member pulled out from the protective sheath, fixes the sheath gripper to the protective sheath, and inserts the tension member into the ring. When the tension member is pulled, the sleeve comes into contact with the ring of the sheath gripper and is prevented from coming off, and the traction force is transmitted to the sheath gripper via the ring, so that the tension member and the protective sheath are It can be towed while fixed together. In addition, when bending the tension member, the tension member can move left and right within the range of the gap with the ring, and as it moves, the sleeve swings along the spherical seat. By moving the tension member, the tension member can be easily bent.

``Example'' Hereinafter, an example of the tensioning device for the pulling end of the optical fiber cable according to the present invention will be described in Figures 1 to 3.
This will be explained based on the diagram.

This retainer also includes a sheath gripper 3 for fixing the protective sheath 2 peeled off from the pulled end of the optical fiber cable 1, and
The tension member 4 has a sleeve 5 which is placed over the tension member 4 and fixed by caulking or the like, and a traction line 7 is connected to the tip of the tension member 4 protruding from the sleeve 5 via a coupler 6. The difference between the tip of the towing line 7 and the outer surface of the protective sheath 2 of the optical fiber cable 1 is covered with a flexible protective pipe 8 made of polyvinyl chloride or the like, compared to the conventional method shown in FIG. Although similar to the example,
In one embodiment, the sheath gripper 3 and the sleeve 5 are separated, and the sleeve 5 is connected to the tension member 4.
The difference is that the head can be swung according to the bending of the blade.

To explain these details, a contraction tube 9 is wrapped around the surface of the protective sheath 2 near the pulling end of the optical fiber cable 1, and the contraction tube 9 and the protective sheath 2 are integrally attached to the sheath gripper 3. It is now fixed by The sheath gripper 3, as shown in FIG.
It has a double cylindrical shape with an inner cylinder 10 inserted inside the peeled protective sheath 2 and an outer cylinder 11 covered from the outside of the contraction tube 9, and
The protective sheath 2 gripping portions (portions indicated by A in FIGS. 1 and 2) of both cylinders 10 and 11 are formed thin so that they can be plastically deformed by caulking. Then, a sealing tape 12 is wrapped around the shrinkable tube 9, and the protective sheath 2 is interposed between the two cylinders 10 and 11, and the protective sheath 2 and the shrinkable tube 9 are strengthened by caulking the outer cylinder 11. It is designed to be held between the Further, a pair of arms 13 are provided on the inner cylinder 10 so as to protrude forward in the traction direction.
A ring 14 through which a portion of the sleeve 5 is inserted is fixed concentrically to the inner cylinder 10 at the tip of the sleeve 3 . Furthermore, a plurality of O-rings 15 are arranged on the outer circumference of the outer cylinder 11 to seal the space between the outer cylinder 11 and the protective pipe 8.
A compression tape 16 is wrapped around the protective pipe 8 to press it against the O-ring 15.

On the other hand, the sleeve 5 has an outer diameter that allows its distal end to be inserted into the hole 14a of the ring 14 with a slight gap g, and a large diameter portion larger than the hole 14a of the ring 14 at its base end. 17 is integrally provided, and a spherical seat 18 that is convex toward the distal end of the sleeve 5 is formed in the large diameter portion 17.

This spherical seat 18 is formed by forming the front surface of the large diameter portion 17 in the traction direction into a convex spherical shape, and is brought into contact with the ring 14 from the rear in the traction direction. When the tension member 4 is bent, the sleeve 5 can swing while sliding along the spherical seat 18 within the gap g between the ring 14 and the sleeve 5.

An eye nut 20 is connected to the tip of the traction line 7 via a plug 19, and caps 21A and 21B made of polyvinyl chloride, rubber, etc. are attached to the outer peripheries of the plug 19 and the contraction tube 9, respectively. are provided, and these caps 2
The protection pipe 8 is arranged between 1A and 21B.

As shown in FIG. The protective sheath 2 and the contraction tube are inserted between the cylinders 10 and 11 of the sheath gripper 3 with the ring 14 inserted through the hole 14a of the ring 14 and the spherical seat 18 of the large diameter portion 17 of the sleeve 5 in contact with each other. 9 and a sealing tape 12, the outer cylinder 11 is caulked, and the protective sheath 2 and the like are firmly held between the two cylinders 10 and 11. Further, the traction line 7, the eye nut 20, etc. are sequentially attached to the tension member 4 in a connected state, and after these are all covered with a protective pipe 8, a compression tape 16 is wrapped around the outer periphery of the protective pipe 8. In this state, the optical fiber cable 1 is inserted into the conduit by pulling the eye nut 20 as shown by the arrow in FIG. 1.

In this case, the traction force is of course transmitted to the tension member 4 via the traction line 7,
The large diameter portion 17 of the sleeve 5 fixed to the tension member 4 comes into contact with the ring 14 of the sheath gripper 3 and is prevented from coming off, and the traction force acting on the tension member 4 causes the ring 14 to be removed from the sleeve 5. The information is transmitted to the sheath gripper 3 via the
The protection sheath 2 integrated with the sheath gripper 3 can also be pulled while applying a traction force. That is, although the sleeve 5 and the sheath gripper 3 are separate parts, the tension member 4 and the protective sheath 2 are integrally fixed by the traction force transmission action between the large diameter portion 17 and the ring 14. It has the function of

On the other hand, at the bent portion of the conduit, the flexible protective pipe 8 bends the entire structure, and the sleeve 5 inserted into the ring 14 of the sheath gripper 3 changes the pulling direction of the tension member 4. Accordingly, the ring 14 is integrated with the tension member 4.
By being slid along the spherical seat 18 in an oscillating manner as shown by the arrow in FIG. 2 within the range of the gap g between the hole 14a and the hole 14a, the spherical seat 18 is tilted as shown by the chain line in FIG. The tension member 4 can be bent near its rear end. Also,
When the optical fiber cable 1 is inserted into a conduit and the tensioned end thereof is to be fixed to a junction box, after removing the coupler 6, the part of the tension member 4 protruding from the sleeve 5 is Even if the length is short, it is easy to bend the tension member 4 by swinging the sleeve 5 along the spherical seat 18, and if it is necessary to handle it while bending it, bend the tension member 4 in the same way. This makes it easier to handle and improves its handling.

In addition, in the retainer of the present invention, the sleeve does not necessarily need to be inserted through the ring of the sheath gripper, but at least the tension member is inserted and the sleeve fixed to the tension member is brought into contact with the ring. It suffices if the structure is in contact with the two. Further, the spherical seat may be provided on the ring, or may be provided on both the ring and the sleeve.

When a spherical seat is provided on the ring, the rear surface in the traction direction where the large diameter part of the sleeve contacts should be formed into a concave spherical shape with a larger diameter than the large diameter part, and when it is provided on both the ring and the sleeve, The sleeve may be provided with a convex spherical seat, and the ring may be provided with a concave spherical seat that abuts the convex spherical seat of the sleeve. Furthermore, if a spherical seat is formed on both the sleeve and the ring, the curvature of the spherical surfaces may be made almost the same to form a fitted state, and other detailed configurations are also limited to one embodiment. isn't it.

"Effects of the Invention" As explained above, according to the optical fiber cable pulling end fastener according to the present invention, the following effects can be achieved.

() When the optical fiber cable is fixed and pulled, the sleeve comes into contact with the ring of the sheath gripper due to the traction force acting on the tension member and is prevented from coming off, and the traction force is transferred from the sleeve through the ring. Since the transmission is transmitted to the sheath gripper, it is possible to pull the tension member of the optical fiber cable and the protective sheath while they are integrally fixed by the sleeve and the sheath gripper, thereby preventing their displacement. be able to.

() The sleeve fixed to the tension member and the ring of the sheath gripper are in contact with each other via a spherical seat, and there is a gap between the ring and the tension member inserted therein. Therefore, the sleeve can swing along the spherical seat within this gap, and even if the length of the tension member pulled out from the sleeve to the tip is short, the tension member can be easily bent by swinging the sleeve. As a result, it is possible to prevent the length of the retaining member from increasing in length, and improve the workability of pulling the inside of the bent pipe, connecting the tension member and the connection box, etc.

[Brief explanation of drawings]

Fig. 1 is a partially cut-away front view showing an embodiment of the retainer of the present invention, Fig. 2 is a partially cut-away front view of the sheath gripper shown in Fig. 1, and Fig. FIG. 2 is a side view of the inner cylinder, and FIG. 4 is a partially sectional front view showing a conventional example of a retainer. DESCRIPTION OF SYMBOLS 1... Optical fiber cable, 2... Protective sheath, 3... Sheath gripper, 4... Tension member, 5... Sleeve, 6... Coupler, 7... Traction line, 8... Protective pipe, 9...Shrink tube, 1
0...Inner cylinder, 11...Outer cylinder, 12...Sealing tape, 13...Arm, 14...Ring, 15
... O-ring, 16 ... Compression tape, 17 ... Large diameter part, 18 ... Spherical seat, 19 ... Plug, 20 ...
... Eye nut, 21A, 21B... Cap, g
……gap.

Claims (1)

[Scope of utility model registration request] The protective sheath 2 at the end of the optical fiber cable 1 is pulled in a state where the protective sheath 2 at the end of the optical fiber cable 1 and the tension member 4 pulled out from the protective sheath 2 are integrally fixed. and a sleeve 5 fixedly placed over the tension member 4 at a position forward of the end of the protective sheath 2 in the direction of traction. A ring 14 is provided in which the tension member 4 is inserted with a gap, and when the tension member 4 is towed, the sleeve 5 comes into contact with the sleeve 5 from a rear position in the traction direction to prevent it from coming off, and the ring 14 and the sleeve A spherical seat 18 having a spherical surface formed on at least one of the abutting parts with the sleeve 5 and allowing the sleeve 5 to swingably slide on the ring 14.
An optical fiber cable pulling end fastener, characterized in that it is provided with: