JPS59175318A - Method of connecting branch for communication cable and its connecting tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a branch connection method for communication cables and a connection tube used to carry out the method.

The telephone line is connected from an underground feeder cable to an underground distribution cable, and is further wired from a branch connection to a subscriber or each telephone box. This branch connection is usually covered with a hard case made of lead pipe or PVC in order to avoid water intrusion and the influence of external forces.

Conventionally, for a branch connection section that connects a branch cable to a main cable, the entire connection section has been covered in one case, and the case has been filled with resin.

For example, in a branch connection using the UG method using a conventional CCP-JF cable, as shown in Figure 1, the main cable 1
, 1' is covered with two vertically divided cases 2 and 2', each case is screwed by inserting a sealing ring between the mating surfaces, and then case 2 is connected.
The inside of the case is filled with resin 4 through a hole 3 provided in the upper part of the case, and the branch cable 5 at this time is pulled out from the end of the case in parallel with the main cable. In the figure, 6 indicates a connecting rod having a wire holding hanger 7, and 8 indicates a backing that closes the opening at the end of the case.

As mentioned above, the current case that houses the entire fiber connection section where all the cable cores are connected is large because it requires a large internal space, and the number of branch cables that can be pulled out from the end of the case is also large. Since the maximum number of cables is limited to four cables (two cables per side), in areas where there are many subscribers, it is necessary to install several additional UG connections and connect branch cables, which increases the connection cost. Since a trapezoidal handle hole is required to accommodate these connecting parts underground, it has poor economic efficiency and road occupancy. Furthermore, in the UG method,
In order to prevent water from entering due to plastic deformation of the hard case, the inside of the case is filled with resin, and when adding or switching branch cables after construction, all the resin from the core wire connections must be removed, making it extremely difficult. Bad sex. In addition, due to its structure, the case has to be manufactured by injection molding or the like, making it expensive.

Furthermore, conventionally, the mating surfaces of the case 2 and 2', which are divided into two parts, are joined together by the tightening force obtained by tightening screws. .

However, since the case is split vertically, the length of the split part is long, so if you want to apply sufficient tightening force to the entire case using the screw tightening method, you will need a large number of screws and tools such as screwdrivers. This makes it necessary and the workability deteriorates. Roughly,
When tightening screws, the initial tightening force is large, but the warping force is attenuated due to plastic deformation of the case or reduction in elasticity or deformation of the sealing material, resulting in a decrease in the degree of sealing of the case and a risk of flooding accidents. There are problems like this.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a branch connection method with excellent workability and a connection tube suitable for carrying out the method.

The present invention will be explained below based on the embodiments shown in FIGS. 2 to 9.

First, to explain the structure of the connecting tube, the connecting tube 9 has an inverted U-shape in which both ends of an elastic tube 10 made of rubber or the like are bent downward.
The main cable 1 is installed at the bottom of the bend, that is, at both ends of the tube.
A hole 11 is provided for passing through. Further, a half part 12 is formed along the entire length of the upper outer periphery, and the whole part can be opened on one side as shown by the chain line in FIG. A protrusion 14 with a sealing material 13 interposed therebetween and provided opposite to the outer periphery of the half side part.
, 14' are provided with removable fasteners 15, thereby providing a liquid-tight seal.

This fastener 15 is configured to apply a uniform fastening force over the entire length of the half portion 12 of the tube 9.

J That is, this fastening tool 15 has a protrusion 14.J of the half portion 12.
A plurality of clamp members 18 are attached at regular intervals to one side of a pair of support bars 17, 17' which are longitudinally attached to grooves 16, 16' of 14'. It is formed by bending a steel wire into a U-shape, and curving both upright ends of the wire so as to draw an incomplete circle in the same direction when viewed from the side, and the clamping member 18 at one end is hinged. This is to ensure that even if the bar 17 is bent in the middle as shown in FIG. 5, there will be no problem in attachment/detachment operation. the other groove 16 of
The other end of the clamp member 18 (
By locking the ends), a clamping force is applied to the halves 12 of the tubes 9 that are butted together through the sealing material 13, but at this time, the bar 17 is bent and the clamp member 18 is completely fixed. When I traced it, I found that the 6th
As shown by the chain line in the figure, the clamp member 18 cannot be rotated, making it impossible to release the clamp. Therefore, as described above, one end of the clamp member 18 is hinged to eliminate this disadvantage.

However, when the bar 17 is formed straight, the clamp member 18 is completely fixed and the bar 17 is formed at a predetermined time.
It may also be made to rotate.

Note that the clamp member 18 may be a straight spring steel plate bent into an incomplete circle.

Incidentally, such a fastener 15 can also be applied to a connection case that is divided into two in the length direction, and in that case, two of the same fastener will be prepared.

Further, the duplex 9 has one lower side surface formed flat, and a plurality of caps 20 having screws are integrally molded on this surface as shown in FIG. This serves as a core wire pull-out hole for the branch cable 5.

Note that a5, since the wire pulling hole 21 normally needs to be closed, it has a structure in which a rubber membrane is integrally molded and it is cut out with a knife or the like when pulling out the wire.

By the way, the inner surface of the central part of the tube 9 that extends straight has strength against external pressure. i In order to further improve the moisture prevention effect, it is desirable to integrally mold the reinforcing plate 22 using a lightweight material such as aluminum.

Further, a connection sleeve 23 is attached to the cap 20 of the cut-out core wire pull-out hole 21 .

As shown in FIG. 8, this sleeve 23 has a hollow joint 26 with screws 24° and 25 at the small diameter tip and large diameter rear end, and a rubber etc. with a branch cable inlet 27 at one end. A cylindrical case, the rear end of which is integrally molded with the other end of the sleeve 28, has an elastic sleeve 28 and a screw 29 at its tip that engages with the rear end screw 25 of the hollow joint 26. 30, and an O-ring 32 that seals the gap between the case 30 and the hollow joint 26, and when the tip screw 24 of the hollow joint 26 is screwed into the base 20 via the O-ring 31, , and is adapted to be liquid-tightly coupled to the branch connecting tube 9.

Next, a branch connection method using the tube configured as described above will be explained.

First, the main cable 1 is loosened in a loop shape as shown in FIG. 9 within the handle hole, and the required length of the outer sheath 1a of the cable 1 is stripped off at this loop portion. Next, the half part 12 of the duplex 9 is opened, and a part of the jacket is inserted into the bent part of the tube end without cutting the core wire, as shown in FIG. 2. Store it like this. After this, a sealing tape 33 is wrapped around the outer circumference of the main cable 1 so as to fill the gap between it and the inside of the tube hole, and the end of the tube 9 is sealed liquid-tightly with the resin 34.

Next, the gripping tools 35 are used to connect and fix both ends of the tube 9 and the main cable 1 extending therefrom, thereby preventing relative displacement of the tube and the main cable 1 and deformation such as twisting of the elastic duplex 10. In this way, the elastic tube 10
After the protection of the main cable jacket removed part and the fixing of the main cable 1 are completed, the desired core wires to be branched are cut at the lowest end of the jacket removed part of the main cable 1 at ftfA, and the core wires are inserted into the core wire draw-out hole. 21 to the outside (.

Next, after passing the cut core wire through the hollow joint 26 of the connection sleeve 23, the joint 26 is attached to the base 20 via the O-ring 31 (see Figure 2). After passing the branch cable 5 through, the branch cable 5 and the core wire pulled out from the tube 9 are connected. After this work, the elastic sleeve 28 is attached to the joint 26 via the O-ring 31, and then taping 36 is applied to the branch cable entrance of the connection sleeve 23 for waterproofing.

Thereafter, a sealing ring 13 is interposed between the mating surfaces of the fifth half part 12 of the tube 9, and a fastener 15 is attached to apply a tightening force to the entire length of the half part 12.

This reliably seals the connection point -19.

Complete the connection work as described above.

By the way, the purpose of bending both ends of the tube 9 into an inverted U shape is to shorten the length of the connection part in the longitudinal direction, but by adopting such a structure, the resin 34 can be injected only into both ends of the duplex. It becomes possible to do this, and i of this part
l Water immersion reliability can be improved. In this case, after attaching the fastener 15 only to the bent end of the duplex 9, that is, the area indicated by B in FIG. 2, the resin 34 is injected,
Thereafter, the joined half portions are clamped, and then the resin 34 is cured.

Then, when reconnecting, the straight half part of duplex 9,
That is, it is sufficient to disassemble only the part shown by C in FIG. 2 and perform the same work as above'ylf.

As explained above, according to the connection method of the present invention, the core wires of the main cable are housed in the tube without being cut, and then the half portion of the tube is opened and only the necessary core wires are removed from the tube. Pulling out and connecting the core wires for each cable is done outside the tube, which greatly improves work efficiency and reduces work time.

Furthermore, by separating the main cable lead-through core part and the branch cable connection part, it is now possible to disassemble only the branch cable connection part, instead of the conventional method of dismantling the entire connection part when adding a branch cable. This can be done by adding more units, and the workability during maintenance will be greatly improved.

Further, according to the connection tube of the second invention, by pulling out the core wire of the main cable to the outside from the lower side of the duplex and connecting it to the branch cable, it is possible to take out the multi-strand branch cable from one connection point. It is possible to reduce the number of branch connections (not only can the number of branch connections be installed), but it is also smaller compared to conventional connections, so the hand hole can be made smaller, making it economically viable. Furthermore, the structure is simple and easy to manufacture, the internal space is small, so it can be provided at low cost, and it has excellent waterproof properties.

Further, according to the connecting tube of the third invention, the clamp member is attached to one of the support bars after the pair of support bars of the fastener provided therein are aligned with the groove formed in the half portion of the tube. By simply locking the tip of the connector to the bar, a tightening force can be applied to the split portion of the duplex, and therefore the connecting duplex can be sealed easily and quickly.

In addition, since the clamp member has spring elasticity, it can absorb the amount of shrinkage due to plastic deformation of the clamped object, and therefore, it is possible to maintain sufficient clamping force for a long period of time even on rubber duplexes that are difficult to plastically deform. can.

・Furthermore, since the clamping force is applied to the split part through the vertically attached bar, a uniform clamping force is applied over the entire length, which improves the reliability of the waterproof surface C of the connecting duplex. will further improve.

A further advantage is that no special tools are required for the fasteners.

Further, according to the connection tube of the fourth invention, an elastic sleeve is used for the connection sleeve provided therein, and each fastening portion is sealed via an O-ring, so that the connection tube is filled with resin to ensure waterproof function. There is no need to do so, and therefore the connection part can be opened and closed freely, making it easier to layer the branch wobble and switch connections after new installation.

In addition, the connecting sleeve has a simple structure, so it can be manufactured at low cost, and by using this, the connecting duplex body can also be manufactured at low cost because the structure is simplified and it can be molded using only a mold. Therefore, there are advantages such as the total cost required for the connecting portion is lower than that of the conventional method.

[Brief explanation of the drawing]

Fig. 1 shows a conventional branch connection connecting tube using a UG connection, Fig. 2 is a partially cutaway front view of the connecting tube, and Fig. 3 is a view taken along the line ■-■ in Fig. 2. Cross section, 4th
The figure is a partially cutaway bottom view of the connecting duplex, and Figure 5 is a partial front view showing how the fastener is used in the connecting tube.
FIG. 6 is an enlarged sectional view taken along the line Vl-Vl in FIG.
FIG. 7 is an enlarged front view showing a part of the fastener, FIG. 8 is a half sectional view of the connecting sleeve, and FIG. 9 is a front view showing the entire branch connection part. 1...Main cable, 2...--Case, 5
... Branch cable, 9 ... Connection tube, 10 ... Elastic tube, 12 ...
Half part, 15... Fastener, 16゜16'...
...Groove, 17.17' ...Support bar, 18
... Clamp member, 21 ... Core wire draw-out hole, 23 ... Connection sleeve, 26 ... Hollow joint, 27 ... Branch cable introduction Mouth, 28・
...Elastic sleeve, 29 ...Screw, 30
...Case, 32...O-ring. Continued from page 1 0 Inventor: Aya Masuzawa, 8-4 Kyobashi 2-chome, Chuo-ku, Tokyo, Tsuken Engineering Co., Ltd., Hinai ■Applicant: Sumitomo Electric Industries, Ltd., 8-4 Kyobashi 2-chome, Chuo-ku, Tokyo

Claims (1)

[Scope of Claims] (1) After stripping off the required length of the outer sheath of the main cable looped at the branch connection section at the loop section, the stripped section is removed without cutting the core wire of the stripped section. The outer periphery of the upper part is split in half from one end to the other, and the half part is housed in an inverted U-shaped elastic tube that is clamped in a liquid-tight manner and can be opened and closed, and then the bent tube end is sealed in a liquid-tight manner. A branch connection method for communication cables, which is characterized in that only the desired core wire is pulled out from the core wire draw-out hole provided on the lower side surface of the tube, and a branch cable is connected to this. (2) Both ends The upper outer periphery of the elastic tube, which has a hole through which the main cable is passed, and whose entire shape is an inverted U-shape, is cut in half in the longitudinal direction from one end to the other, and this half is separated by a clamping means. A communication cable branch connection tube that is liquid-tight and can be opened and closed, and is characterized by having a plurality of core wire pull-out holes on the bottom side of the elastic tube. (3) The main cable can be connected to both ends. Only the upper outer periphery of the elastic tube, which has a through hole and an inverted U-shaped rest, is divided in half in the length direction from one end to the other, and this half part can be opened and closed in a liquid-tight manner by a clamping means. Clamp freely,
Roughly speaking, a plurality of core wire draw-out holes are provided in the lower side surface of the elastic tube, and the clamping means includes a pair of grooves longitudinally provided in opposite sides of the half portion of the elastic tube. One end of a clamp member made of a spring material curved into an incomplete circle is fixed or hinged to one of the support bars of the support bar, and a plurality of clamp members are attached at approximately regular intervals, and each clamp member is 1. A branch connection tube for a communication cable, characterized in that the end of the elastic tube is locked to the other bar so that a clamping force is applied to the elastic tube half to seal the half. (4) Cover only the upper outer periphery of the elastic tube, which has holes at both ends for the main cable to pass through, and whose overall shape is an inverted U-shape, from one end to the other end, and this half part Clamped liquid-tightly and freely openable and closable by clamping means,
Furthermore, a plurality of wire pull-out holes are provided on the lower side surface of the elastic tube, and a connecting sleeve is attached to the wire pull-out holes, and the connecting sleeve has a tip portion with a small diameter and a tip portion with a large diameter. A hollow joint with threads at one end, a cylindrical sleeve having a branch cable introduction hole at one end and a screw at the other end to be screwed into the large-diameter screw of the previous hollow joint, and this sleeve and the hollow joint. The small-diameter threaded portion of the hollow joint is screwed into the core wire pull-out hole of the elastic tube through the O-ring, and the main cable core wire connected to the outside of the elastic tube is connected to the main cable core wire. A branch connection tube for a communication cable, characterized in that the connection part with the branch cable is housed and protected.