JP2001112142A - Pipe coupling for cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe coupling for cables which requires few number of part items. SOLUTION: This coupling has a coupling body 1 and has fastening push rings 2, which have tips whose internal peripheral surfaces are diameter-extended tapered surfaces 2a, and are attached to the coupling body 1 so as to be able to move forward and backwards spirally. The coupling has come-off preventing rings 3 which receive forces G in directions of reducing diameters by contact with the tapered surfaces 2a of the fastening rings 2, and welded to the peripheral surfaces P2 of pipes P to be connected. The coupling has sealing materials 4, which perform sealing action between the fastening rings 2 and the pipes P, and has circular cushioning members 5 put between the tip surfaces P1 of the pipes P and the stepped parts 1a of the coupling body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a joint for cable piping.

[0002]

2. Description of the Related Art Conventionally, an electric fusion connection (EF) for connecting a pipe to be connected to a joint body by heat fusion by heating a heater or the like incorporated in the joint body.
Connection) is widely used.

[0003]

However, the conventional joint structure is expensive because a heater or the like is incorporated in the joint body. In addition, the time required for heat fusion of the heater is long, and a process of scraping off the deteriorated layer on the pipe surface is required, so that much labor is required for connection work. Furthermore, when reworking or repairing, the heat-sealed pipe cannot be replaced, which is inconvenient.

Accordingly, an object of the present invention is to provide a joint for a cable pipe which is inexpensive, can be operated safely and in a short time, can easily connect pipes, and has no pull-out and no air leakage. And Another object of the present invention is to provide a joint for a pipe for a cable that can ensure the sealing performance even when the cut surface of the pipe is inclined.

It is another object of the present invention to provide a joint for a cable pipe which can smoothly insert a cable into a pipe by making the inner surface of a connection portion smooth. It is another object of the present invention to provide a cable piping joint having a small number of parts.

[0006]

In order to achieve the above-mentioned object, a joint for a cable pipe according to the present invention has a joint body, a tapered inner surface at a distal end and a tapered surface at an enlarged diameter. A tightening push ring screwed into and out of the
A retaining ring which presses against the outer peripheral surface of the connected pipe by receiving a force in a direction of reducing the diameter by contact with the tapered surface of the tightening press ring, and a sealing action between the tightening press ring and the pipe; And a sealing material to be formed.

Further, an annular cushion member made of foamed plastic is interposed between the distal end face of the pipe to be connected and the stepped portion of the joint body. The inner diameter of the pipe to be connected and the inner diameter of the stepped portion of the joint body on the inner end side are the same.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the present invention.

FIGS. 1 to 4 show an embodiment of the present invention. The present invention relates to a pipe (communication cable pipe) P made of a resin pipe such as a vinyl chloride pipe or a polyethylene pipe, a synthetic resin-coated steel pipe or the like. Used to connect And the pipe P
Inside, a communication cable (optical fiber cable, electric wire, or the like) is passed by air, and the communication cable is protected by this pipe (communication cable pipe) P. The present invention, in particular,
It is suitable for polyethylene tubes for burying optical fibers in information boxes.

FIG. 1 shows a use state of the present invention. This joint for a cable pipe has a joint body 1 and a tapered inner surface 2a with a tapered inner surface 2a. Force G in the direction of reducing the diameter due to the contact between the tightening press ring 2 screwed to the
Receiving (see Figure 3) is pressed against the outer circumferential surface P ₂ of the connection pipe P (having a score portion circumferentially) and C-shaped retaining ring 3, between the push ring 2 and the pipe P tightening the seal member 4 forming the sealing action, the distal end face P ₁ of the pipe P, a annular cushion member 5 interposed between the stepped portion 1a of the joint main body 1, and a.

FIG. 2 shows a connection method between the pipe P and the joint. First, as shown in FIG. 2A, a pipe P is inserted in a direction A into a (pre-assembled) joint of a cable pipe. FIG. 2B shows a state in which the insertion of the pipe P has been completed. Note that a tapered surface 11 is formed near the outer end of the inner peripheral surface of the retaining ring 3 so as to smoothly guide the insertion of the pipe P. Taper surface 2a of tightening push ring 2
And the retaining ring 3 are separated from each other.

When the pipe P receives an external force (not shown) in the direction B coming out (from the joint), the retaining ring 3 also moves in the direction B with the movement of the pipe P as shown in FIG. I do. Then, the tapered surface 2 of the tightening push ring 2
a comes into contact with the retaining ring 3 and generates a force G as shown in FIG.

More specifically, as shown in FIG. 3, a force F which has an interaction / reaction relationship between the tapered surface 2a of the tightening push ring 2 and the outer tapered surface 8 of the retaining ring 3 is shown. And the force R act. The retaining push ring 2 is a retaining ring 3
Therefore, since the force F is received, the threaded portions 6 of the joint body 1 and the tightening push ring 2 are further in close contact with each other, and there is no fear that they will be separated. It is also preferable to seal the screw portion 6 with a sealing material (not shown).

G indicates a component (in the direction of reducing the diameter) of the force R received by the retaining ring 3 from the tightening push ring 2. Direction retaining ring 3 has three Article claw portions 3a ..., component force G is the claw portion 3a ..., respectively, the force N _1, the force N _2, acts as a force N _3, the pipe P is reduced in diameter Act on Note that G
= (N ₁ + N ₂ + N ₃ ) holds. And
The component G prevents the pipe P from coming off the joint. The pipe P may be inserted into the joint body 1 first, and then the pipe P may be connected by screwing the fastening press ring 2 to the joint body 1.

FIG. 4 shows a case where the tip end surface P ₁ of the pipe P is inclined. In other words, it is generally difficult to accurately cut the pipe P into a plane perpendicular to the axis, and the pipe P on the right in FIG. 4 is inclined by an angle α in a side view with respect to a plane perpendicular to the axial direction. And the pipe P on the left side of FIG.
Is inclined by an angle β in a side view with respect to a plane perpendicular to the axial direction.

The annular cushion member 5 made of foamed plastic (as described above) is connected to the stepped portion 1 of the joint body 1.
because it is interposed between the a, and when the leading end face P ₁ of the pipe P is inclined, even if such having an uneven, may cause a gap between the stepped portion 1a of the joint main body 1 Absent.

Returning to FIG. 1, the inner diameter D _{0 of the} pipe P is set to be the same as the inner diameter D ₁ on the inner end side of the stepped portion 1a of the joint body 1. The inner diameter D ₂ of the cushion member 5 is also the same as the inner diameter D ₀ (of the pipe P) and the stepped portion 1 a of the joint body 1.
In) in the end side inner diameter D ₁ and is set to approximately equal size.

In the present invention, the design can be changed. For example, the number of the claw portions 3a of the retaining ring 3 is not limited to three, but may be any number. Also, as shown by a two-dot chain line in FIG. 1, a sealing material 10 such as an O-ring or U packing is interposed between the outer peripheral surface of the distal end portion of the pipe P and the inner peripheral surface of the joint body 1. The sealing performance may be improved.

[0019]

Since the present invention is configured as described above,
The following effects are obtained.

Since the number of parts is small (according to claim 1), it can be manufactured at low cost. In addition, the work can be performed safely and in a short time (compared with the conventional electric fusion connection), and the connection work of the pipe P can be easily performed. Further, there is no fear that the pipe P is pulled out and air leaks. Then, the more if such pipe P is pullout, the retaining ring 3 pressed against the outer circumferential surface P ₂ of the pipe P, it exhibits a large resistance force.

According to the second aspect of the present invention, even when the distal end surface P _{1 of the} pipe to be connected P is inclined or has irregularities, the cushion member 5 is connected to the distal end surface P _{1 of the} pipe P. ,
Since the joint body 1 is deformed in accordance with the shape of the stepped portion 1a, the airtightness is secured without generating a gap, and turbulent air flow can be prevented.

Further, the entire pipe P when an external force is applied after the connection of the pipe P is then curved, along with it, the distal end surface P ₁ of the pipe P even when it is about to fail the gap, the cushion member 5, the pipe a front end face P ₁ of the P, so corresponds to the shape of the stepped portion 1a of the joint body 1 is deformed without causing gaps, sealing performance is secured, it is possible to prevent air turbulence. As described above, since the turbulent air flow can be prevented, the wiring operation by air pressure feeding of the communication cable can be performed smoothly (without being caught).

According to the third aspect, since the inner surface of the connection portion between the pipe P and the joint becomes smooth, when the communication cable is passed through the pipe P, the member to be inserted (cable, conductor,
Etc.) can smoothly pass through the connecting portion without being caught by the connecting portion. In addition, the labor and time required for cable passing work can be greatly reduced, and work can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing a use state of the present invention.

FIG. 2 is an operation explanatory view.

FIG. 3 is an operation explanatory view.

FIG. 4 is a sectional side view.

[Explanation of symbols]

1 joint body 1a pushes the stepped portion 2 clamping ring 2a tapered surface 3 retaining ring 4 sealing member 5 cushion member D ₀ inside diameter D ₁ (inner end side) inner diameter G (min) force P (the connection) pipe P ₁ tip surface P ₂ outer peripheral surface

Claims (3)

[Claims] 1. A joint body 1, a clamp press ring 2 having a distal end inner peripheral surface formed as a tapered surface with an enlarged diameter 2a and screwed to the joint body 1 so as to be able to advance and retreat, and the clamp press ring. 2
G in the direction of reducing the diameter by contact with the tapered surface 2a
Features and retaining ring 3 which presses the outer circumferential surface P ₂ of the connection pipe P undergo, the seal member 4 forming the sealing action between the press tightening ring 2 and the pipe P, that is composed of Cable piping fittings. 2. A method annular cushion member 5 made of foamed plastic, a distal end face P ₁ of the connection pipe P, cable pipes, characterized in that interposed between the stepped portion 1a of the joint main body 1 Fittings. Wherein the inner diameter D ₀ of the connected pipe P, joint piping cable, characterized in that the inner end side inner diameter D ₁ of the stepped section 1a of the joint body 1 and the same.