JPH07260056A - Pipe coupling for protecting pipe of communication cable or the like - Google Patents

Abstract

PURPOSE:To easily dispose a stopper in a coupling main body, reduce a manufacturing cost, prevent deterioration of strength of the coupling main body, and smoothen inserting work of a cable or the like. CONSTITUTION:A pipe coupling comprises a metallic coupling main body 11 for connecting protecting pipes 4, 4 to each other, an annular packing 12 fitted at both ends of the inner surface of the coupling main body 11, and a tapered pin-like stopper 13 press-fitted into a disposing hole formed at the center in the axial direction of the coupling main body 11 from the outside and projected at the center of the inner surface of the coupling main body 11. A projecting length of the stopper 13 projecting inward of the coupling main body 11 is set slightly smaller than a distance between the inner surface of the coupling main body 11 and the inner surface of the protecting pipe 4 inserted into the coupling main body 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting a protective pipe such as a communication cable buried under an asphalt pavement or in a gutter of a highway.

[0002]

2. Description of the Related Art A pipe joint of this type developed by the present inventor is shown in FIG. This is because the annular packing 2 is fitted into the concave step portions 1a at both ends of the inner surface of the synthetic resin tubular joint body 1, and the annular stopper 3 is integrated with the joint body 1 at the center of the inner surface of the joint body 1. The end portions 4a, 4a of the protective tubes 4, 4 such as metal communication cables, which are projected and are slightly smaller in diameter than the joint body 1, are inserted into both end portions of the joint body 1 via the annular packings 2. By making the end surfaces of the protection tubes 4 and 4 contact the annular stopper 3, the insertion lengths L of the protection tubes 4 and 4 are made substantially the same, and the protection tubes 4 and 4 are connected to each other with the joint body 1 After the connection is completed, a communication cable or the like (not shown) is inserted through the protective tubes 4 and 4.
Further, the joint body 1 and the protective tubes 4 inserted thereinto
The gap α formed between the protective pipes 4 and 4 allows the protective pipes 4 and 4 to be displaced by a predetermined angle θ in the transverse direction with respect to the joint body 1 (see phantom line in FIG. 5). Can be connected according to the curved shape of the road in which it is buried.

[0003]

In the above structure, since the joint body 1 is molded from a synthetic resin material, an expensive molding die is required and the manufacturing cost is high.

Therefore, as shown in FIG. 6, the joint main body 1 is formed of a metal pipe such as a steel pipe, and an annular groove 5 is formed in the center of the inner surface of the metallic joint main body 1. It is conceivable to mount a ring-shaped stopper 3 in a split shape.

According to this structure, since the metal pipe is used as the joint body 1, the joint body 1 made of the synthetic resin described above is used.
Although the manufacturing cost can be reduced as compared with the above, since the annular groove 5 is formed by cutting the central portion of the inner surface of the joint body 1, the cutting cost is high and the annular stopper 3 is expanded and contracted in the radial direction. Since it is necessary to mold it into an annular shape using a possible material, the manufacturing cost of the annular stopper 3 is relatively high, and the annular stopper 3 in a reduced diameter state using a diameter reducing tool or the like is used for the joint body 1 It is necessary to insert it into the annular groove 5 and mount it in the annular groove 5, which is troublesome and time-consuming.

Moreover, for example, the joint body 1 is deformed by being stacked and stored, and the joint body 1 is deformed.
The circularity of the joint main body 1 may change, and when the inner surface of the joint main body 1 having the irregular circularity is cut to form the annular groove 5, as shown in FIG. Annular groove 5
There is a risk that the wall thicknesses t1 and t2 with the bottom surface of the joint become non-uniform, the strength of the thin portion (t1) is extremely reduced, and the joint body 1 may be broken from that portion. The inner peripheral portion 3a of the annular stopper 3 projects inward from the inner surface of the protective tube 4 due to the thick portion (t2), and the guide member connected to the tip of the cable or the like is inserted into the protective tubes 4 and 4. When inserting the cable or the like into the protective tubes 4 and 4, the guide member may be caught by the protruding portion H of the inner peripheral portion 3a of the annular stopper, which may hinder the insertion of the cable or the like.

In view of the above problems, the present invention makes it possible to easily attach the stopper to the joint body, reduce the manufacturing cost, and reduce the strength of the joint body such as a cable. It is an object of the present invention to provide a pipe joint for a protective pipe such as a communication cable, which can be smoothly inserted.

[0008]

In order to achieve the above object, the invention according to claim 1 is such that annular packings are fitted into both end portions of the inner surface of the tubular joint body, and a stopper is provided at the center portion of the inner surface of the joint body. Is provided, the end of the protective tube such as a metal communication cable having a diameter slightly smaller than the inner diameter of the joint body is inserted into both ends of the joint body through the annular packing, and the end surface of each protective tube is In a pipe joint for a protective pipe, such as a communication cable, in which the protective pipes are connected to each other by bringing them into contact with a stopper, the stopper is a pin-shaped attachment that is provided at the axial center of the metal joint body. The protrusion length of the stopper, which is inserted from the outside into the central portion of the inner surface of the joint body and protrudes into the joint body of the stopper, is defined by the inner surface of the joint body and the inside of the protective tube inserted into the joint body. It is characterized in that it has slightly smaller equal to the spacing between the.

According to a second aspect of the present invention, in the first aspect of the present invention, at least one of the outer peripheral surface of the stopper and the mounting hole is formed in a tapered shape with a constriction, and the stopper is It is characterized by being press-fitted in the mounting hole.

[0010]

In the invention described in claim 1, for example, when a protection tube for a communication cable or the like is buried in an asphalt-paved road or a gutter of a highway, a pin-shaped stopper is provided at the central portion in the axial direction of the joint body. After mounting it in the mounting hole and projecting its pin-shaped stopper at the center of the inner surface of the joint body, insert the end of the protective tube into both ends of the joint body through the annular packing, and end face of each protective tube. By contacting the pin-shaped stopper with each other, both protective tubes may be connected to each other via the joint body, and after the connection is completed, the communication cable or the like may be inserted into the protective tube.

In this case, when the pin-shaped stopper is mounted on the joint body, the pin-shaped stopper may be driven or screwed into the mounting hole from the outside of the joint body, and the joint can be mounted very easily.

Further, an inexpensive metal pipe such as a steel pipe is used as the joint body, and a pin-shaped stopper, which is cheaper than the annular stopper described at the beginning, is used as the stopper, and the pin-shaped stopper is used for the joint body. Since it is only necessary to put it in the mounting hole, there is no need for the troublesome work of cutting the annular groove on the inner surface of the joint body as in the example described at the beginning and installing the annular stopper in the annular groove. Can be cheaper.

Further, the protruding length of the stopper protruding into the joint body is set to be equal to or slightly smaller than the distance between the inner surface of the joint body and the inner surface of the protective tube inserted into the joint body. When inserting a guide member connected to the tip of a cable or the like into a protective tube and inserting the cable or the like into the protective tube, the guide member does not get caught by the stopper, and the cable or other work can be smoothly inserted. You can

Further, even if the joint body is deformed and its roundness is deviated, the pin-shaped stopper can be provided in a predetermined manner at the center of the inner surface of the joint body regardless of the deviation. There is no fear that the strength of the joint body will be reduced or that the tip of the stopper will protrude inward from the inner surface of the protective tube as in the above example.

According to the second aspect of the present invention, at least one of the outer peripheral surface of the stopper and the mounting hole is formed in a tapered shape so that the stopper is forced into the mounting hole. The stopper can be press-fitted into the mounting hole simply by driving into.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a state in which protective pipes 4 and 4 for cables and the like are connected by a pipe joint according to an embodiment of the present invention. The pipe joint is a tubular joint body 11 and the joint body 1
It is composed of an annular packing 12 fitted in the recessed step portions 11a at both ends of the inner surface of No. 1 and a pin-shaped stopper 13 protruding from the central portion of the inner surface of the joint body 11.

The joint body 11 is formed of a metal pipe such as a steel pipe, and can be formed by simply cutting a long metal pipe into a circular slice at predetermined intervals in the longitudinal direction.
Production costs can be reduced. Further, because of its high strength, it is possible to reduce the outer diameter of the joint body 1 made of synthetic resin shown in FIG. Furthermore,
The protective pipe 4 is made of a metal pipe such as a steel pipe, has a diameter slightly smaller than the inner diameter of the joint body 11, and forms a slight gap α between the joint body 11 and the protective pipes 4 and 4 inserted therein. Due to the gap α, the protective tubes 4 and 4 are connected to the joint body 11
It is possible to displace by a predetermined angle θ in the transverse direction (see phantom line in FIG. 1), whereby the protection tubes 4 and 4 can be connected according to the curved shape of the road or the like in which they are buried.

The annular packing 12 is made of an elastic material such as rubber or synthetic resin, and a plurality of annular projections 12a protruding on the inner surface side thereof are inserted into both ends of the joint body 11 to protect the outer circumference of the protection tubes 4, 4. No matter how the protective tubes 4 and 4 are displaced in close contact with the surface, the contact state can be reliably maintained and airtightness can be maintained.

The pin-shaped stopper 13 is made of a metal such as steel or a synthetic resin such as vinyl chloride resin (PVC). In this embodiment, it is formed in a tapered pin shape as shown in FIG. As shown by the phantom line, by simply driving from the outside of the joint body 11 into the tapered mounting hole 14 penetrating the axially central portion of the joint body 11, the mounting hole 14 can be press-fitted in a watertight manner. Can, fitting body 1
By making the end faces of both protective tubes 4 and 4 inserted into both ends of 1 contact the stopper 13, the insertion lengths L of the protective tubes 4 and 4 into the joint body 11 are made substantially the same. The protection tubes 4 and 4 can be reliably connected via the joint body 11.

The projection length r of the stopper 13 projecting into the joint body 11 is slightly smaller than the distance R between the inner surface of the joint body 11 and the inner surfaces of the protective tubes 4 and 4 inserted in the joint body 11 ( Or the same or slightly smaller), the guide member connected to the tip of the cable or the like is inserted into the protective tubes 4 and 4, and the guide member is inserted when the cable or the like is inserted into the protective tubes 4 and 4. Does not get caught on the tip of the stopper 13, and the work of inserting a cable or the like can be performed smoothly.

Even if the joint body 11 is deformed and its roundness is deviated, the pin-shaped stopper 13 can be provided in a predetermined manner at the center of the inner surface of the joint body 11 regardless of the deviation. Unlike the pipe joint shown in FIG. 7, there is no risk that the strength of the joint body 11 will decrease and that the tip of the stopper 13 will protrude inward from the inner surface of the protective pipes 4, 4.

According to the above construction, a metal pipe such as an inexpensive steel pipe is used as the joint body 11, and a pin-shaped member which is cheaper than the annular stopper 3 shown in FIG. 6 is used as the stopper 13. It suffices to insert the pin-shaped stopper 13 into the mounting hole 14 from the outside of the joint body 11, and as in the pipe joint shown in FIG. 6, the inner surface of the joint body is cut into an annular groove, and the annular stopper is formed in the annular groove. Since the troublesome work of mounting is unnecessary, the manufacturing cost can be reduced.

In the above embodiment, the outer peripheral surface of the stopper 13 and the inner peripheral surface of the mounting hole 14 are formed in a tapered shape, but the invention is not limited to this. For example, the diameter of both ends is a straight pin shape. The stopper 13 may be press-fitted into the tapered mounting hole 14 or, conversely, the tapered stopper 13 may be press-fitted into the straight mounting hole 14 having the same diameter at both ends.

Further, the stopper 1 is provided on the inner surface of the joint body 11.
Although only one protrusion 3 is provided, a plurality of protrusions 3 may be provided at predetermined intervals in the circumferential direction. As a result, the end portions 4a, 4a of the protective tubes 4, 4 inserted into both ends of the joint body 11 can be positioned more reliably.

Further, although the taper pin is used as the stopper 13, instead of this, as shown in FIG. 4, a screw such as a screw or a bolt is used, and the screw-shaped stopper 1 is used.
Female threaded mounting hole 1 in which 3 is provided in the center of the joint body 11
Alternatively, the stopper 13 can be more securely fixed to the joint body 11.

[0026]

According to the first aspect of the present invention, when the pin-shaped stopper is mounted on the joint main body, it suffices to drive or screw the pin-shaped stopper into the mounting hole from the outside of the joint main body. can do.

In addition, an inexpensive metal pipe such as a steel pipe is used as the joint body, and a pin-shaped stopper, which is cheaper than the annular stopper described at the beginning, is used as the stopper, and the pin-shaped stopper is used for the joint body. Since it is only necessary to put it in the mounting hole, there is no need for the troublesome work of cutting the annular groove on the inner surface of the joint body as in the example described at the beginning and installing the annular stopper in the annular groove. Can be cheaper.

Further, since the protrusion length of the stopper protruding into the joint body is set to be equal to or slightly smaller than the distance between the inner surface of the joint body and the inner surface of the protective tube inserted into the joint body, When inserting a guide member connected to the tip of a cable or the like into a protective tube and inserting the cable or the like into the protective tube, the guide member does not get caught by the stopper, and the cable or other work can be smoothly inserted. You can

Further, even if the joint body is deformed and its roundness is deviated, the pin-shaped stopper can be provided in a predetermined manner at the center of the inner surface of the joint body regardless of the deviation. As in the above example, there is no possibility that the tip end portion of the stopper protrudes inward from the inner surface of the protection tube, or the strength of the joint body decreases.

According to the second aspect of the present invention, since at least one of the outer peripheral surface of the stopper and the mounting hole is formed in a tapered shape with a tapered end, the stopper is forced into the mounting hole. The stopper can be press-fitted into the mounting hole simply by driving into.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state in which protective tubes such as cables are connected to each other by a pipe joint according to an embodiment of the present invention.

FIG. 2 is a view on arrow AA of FIG.

FIG. 3 is an enlarged vertical sectional view of the main part.

FIG. 4 is an enlarged vertical cross-sectional view of a main part showing another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing a state in which protective tubes such as cables are connected to each other by a pipe joint, which is a comparative example.

FIG. 6 is a vertical cross-sectional view showing a state in which protective pipes such as cables are connected to each other by a pipe joint as another comparative example.

FIG. 7 is an enlarged vertical sectional view of the main part.

[Explanation of symbols]

 4 Protective tube for communication cables 4a End of protective tube 11 Joint body 12 Annular packing 13 Stopper 14 Mounting hole r Stopper protrusion length R Distance between inner surface of joint body and inner surface of protective tube

Claims (2)

[Claims] 1. A communication cable made of metal, in which annular packings are fitted at both ends of the inner surface of the tubular joint body, and a stopper is provided at the center of the inner surface of the joint body, the diameter being slightly smaller than the inner diameter of the joint body. Insert the end of the equal protection tube into both ends of the joint body through the annular packing,
In a pipe joint for a protective pipe such as a communication cable in which the end faces of the protective pipes are brought into contact with the stoppers so that the protective pipes are connected to each other, the stoppers are pin-shaped and are made of a metal joint body. The protrusion length of the stopper, which is inserted into the mounting hole provided at the central portion in the axial direction from the outside and protrudes from the central portion of the inner surface of the joint main body, and protrudes into the joint main body of the stopper A pipe joint for a protective pipe such as a communication cable, characterized in that the gap between the inserted protective pipe and the inner surface of the protective pipe is set to be equal to or slightly smaller. 2. The outer peripheral surface of the stopper and the mounting hole, at least one of which is formed in a tapered taper shape, and the stopper is press-fitted into the mounting hole. A pipe joint for a protective pipe such as a communication cable according to Item 1.