JPS5996607A - Coaxial cable - 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 present invention relates to a coaxial cable suitable for use in a system such as a local area network in which a connector pin is inserted into a central conductor to extract a signal without cutting the coaxial cable.

In systems such as local area networks, coaxial cables are used for data transmission, and branch connections are made by inserting connector pins into the center conductor and outer conductor of the coaxial cable from above the insulating sheath while the coaxial cable is live, without cutting it. It is used to send and receive data between G-System terminals and coaxial cables. The method of making a connection by sticking a connector pin into a coaxial cable has the advantage that the connection work can be performed even when the system is in operation, and the connection can be made at any location on the coaxial cable.

FIGS. 1 and 2 show an example i in which the connector pin 2 is connected to the coaxial cable 1 by piercing. The coaxial cable 1 has a central conductor 3 made of copper or aluminum wire, etc.
It has a structure in which an insulator 4, an outer conductor 5, and an insulating sheath 6 are sequentially provided coaxially around the outer periphery of the insulator. For example, a copper wire or an aluminum wire is used as the center conductor 3, a foamed polyethylene or the like is used as the insulator 4, and a metal-plastic laminate tape is used as the outer conductor 5.

For example, a copper braid is used as the metal braid. As the metal/plastic laminate tape, for example, a 2-ester tape laminated on copper or aluminum tape is used with the polyester tape side facing inside. The insulating sheath 6 is made of, for example, polyvinyl chloride. The connector bottle 2 consists of a bottle body 7 and an insulating layer 8 provided on a part of the outer periphery of the bottle body 7 to insulate it from the external conductor 5.

However, in the conventional coaxial cable 1, when the connector pin 2 is completely pierced, a part of the outer conductor 5 is wound up along the connector pin 2, passes through the insulating layer 8, and comes into contact with the bottle body 7, and the outer conductor 5 There was a risk that the center conductor 3 and the center conductor 3 would be electrically short-circuited. That is, when the outer conductor 5 is braided, the wires constituting the braid are hooked onto the tip of the connector bin 2, stretched or cut, and pass through the insulating layer 8 to contact the bin body 7. When the outer conductor 5 is a metal/plastic laminate tape,
The laminated glass nac tape is generally a biaxially stretched tape and has great strength in each direction, so it is not easily torn at the tip of the connector bin 2, and is stretched as the connector bin 2 is pushed, so it is adhered to it. The metal tape also follows and is stretched out, passing through the insulating layer 8 and coming into contact with the bottle body 7. Such an electrical short circuit between the outer conductor 5 and the center conductor 3 may lead to malfunction of system equipment during operation or loss of stored data, and is therefore strictly prohibited.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coaxial cable that can prevent short circuits from occurring when inserting a connector bin.

The present invention provides a coaxial cable in which an insulator, an outer conductor, and an insulating sheath are sequentially provided around the outer periphery of a center conductor.
A layer is provided between the outer conductor and the insulator.

Embodiments of the present invention will be described in detail below with reference to the drawings.

3 and 4 show an embodiment of the coaxial cable 1 according to the present invention. Note that parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals. This embodiment is characterized in that a uniaxially stretched plastic tape layer 9 uniaxially stretched in the longitudinal direction is provided between the outer conductor 5 and the insulator 4. be able to. Alternatively, after the uniaxially stretched plastic Teso layer 9 is spirally wound around the outer periphery of the insulator 4, the outer conductor 5 can be provided by braiding.

According to the coaxial cable 1 having such a structure, when the connector pin 2 is pierced, the uniaxially stretched plastic tape layer 9 is easily torn in the stretching direction due to the pressure of the tip of the pin, and a tear portion 11 is formed. , the outer conductor 5 can be prevented from being stretched. That is, in the case where the outer conductor 5 and the uniaxially stretched plastic tape layer 9 are a laminate tape 10, when the uniaxially stretched plastic TESO layer 9 is torn by the insertion pressure of the connector bin 2, the uniaxially stretched plastic tape layer 9 is torn as in the conventional case. If the plastic tape layer stretches without being cut and the integrated outer conductor 5 stretches along with it, the phenomenon will disappear at once, and the outer conductor 5 will also be easily pierced, minimizing the protrusion toward the center conductor 3 side. It can be done. In addition, in the case of the outer conductor 5 made of a braid, even if the braided wire is caught on the tip of the connector bin 2, the -axis stretched plastic tape layer 9 is torn and separated into left and right parts. can also be prevented from moving to the left or right and protruding toward the center conductor 3. Therefore, connector bin 2
It is possible to prevent a short circuit between the outer conductor 5 and the center conductor 3 when the outer conductor 5 and the center conductor 3 are inserted.

The uniaxially stretched plastic tag used in the present invention is
In addition to those in which stretching is applied only in the longitudinal direction, it also includes those in which the stretching in the longitudinal direction is greater than the stretching in the width direction.

The implementation exception diameter is 2. A center conductor made of Oraysφ mild steel wire is covered with foamed polyethylene as an insulator to a thickness of 1.5 μm, and on top of that is a polyester tape layer uniaxially stretched approximately 4 times in the longitudinal direction and a 15 μm thick polyester tape layer. A laminated tape with an outer conductor made of copper foil is coated vertically with the uniaxially stretched polyester tape layer on the inside, and on top of that, vinyl chloride is extruded and coated as an insulating sheath with a thickness of 1.0. Obtained an invented coaxial cable.

A brass layer connector pin with a thickness of 1.5 mm was inserted into this coaxial cable to contact the center conductor.

In the coaxial cable of the present invention, when the tip of the connector bin hits the laminate tape, the -axially stretched polyester tape layer easily tears in the longitudinal direction, and the copper foil bonded to it also easily tears, forming an outer conductor. The copper foil did not penetrate into the insulator as the connector bin moved, and no short circuit between the center conductor and the outer conductor occurred. The uniaxially stretched I-reester tape used in this example had a tensile strength in the longitudinal direction (stretching direction) of 14 to 25 kg/wm2.
The tensile strength in the width direction (unstretched direction) is 6 to 7 Li2.
The strength in the width direction is about half the strength in the length direction, and it is easy to tear in the width direction.

A central conductor made of seven annealed copper wires with a diameter of 07mφ is covered with polyethylene as an insulator with a thickness of 1.8mm, and on top of it is coated approximately 4 times in the longitudinal direction and in the width direction. about 2 to
A uniaxially stretched polypropylene tape with a thickness of about 25 μm that had been stretched twice was wrapped in 115 wraps to form a uniaxially stretched polypropylene tape layer, and on top of that a uniaxially stretched polypropylene tape with an outer diameter of 0.14 m.
A braided outer conductor made of mφ mild steel wire is applied, and 1
．． A coaxial cable of the present invention was obtained by extruding polyvinyl chloride as an insulating sheath to a thickness of zero.

During this time, a brass layer connector pin with a thickness of 1.5 mm was inserted into the 1111 cable to contact the center conductor.

In the coaxial cable of the present invention, even if a break occurs in the braided strand, the -axis-oriented polyzoropyrene strands are easily torn in the width direction, so the movement of the polyzoropyrene strands at the time of the split causes the braided element to break. The wires were also moved together, the braided strands were no longer drawn in with the connector bin, and no short circuit between the outer conductor and the center conductor occurred.

In addition to polyester (I-lyethylene terephthalate), the material for the -axially stretched plastic TESO is
Conceivable materials include polyethylene, crosslinked polyethylene, polyzolopyrene, vinylidene chloride, polystyrene, etc. as main components.

In addition, there is no practical problem as long as the degree of stretching in the width direction of the -axially stretched plastic tape is less than or equal to the stretching ratio in the longitudinal direction.In fact, it is better to add an appropriate amount of width direction stretching.
This is preferable since the strength during cable manufacture is also maintained.

As explained above, in the coaxial cable according to the present invention, a uniaxially stretched plastic tape layer that is stretched once in the longitudinal direction is installed between the outer conductor and the insulator, and the connector pin is inserted through the insulating sheath. It is possible to prevent the outer conductor from being drawn into the insulator by the insertion force of the connector pin during insertion, and it is possible to prevent short circuit accidents between the outer conductor and the center conductor.

[Brief explanation of drawings]

1 and 2 are cross-sectional views and vertical sectional views showing the state of connection of the connector bin to the conventional coaxial cable, and FIGS. 3 and 4 are examples of the state of connection of the connector bin to the coaxial cable according to the present invention. FIG. 5 is a plan view and a longitudinal sectional view showing an example of the laminated tape used in the present invention. 1... Coaxial cable, 2... Connector bin, 3...
・Center conductor, 4... Insulator, 5... Outer conductor, 6.
... Insulating sheath, 7... Bottle body, 8... Insulating layer,
9...-axially stretched plastic tape layer, 1o... laminate tape. Procedural amendment dated November 29, 1980, Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office■, Indication of the case, Patent Application No. 57-2059922, Title of invention: Coaxial cable (529) Furukawa Electric Co., Ltd.4, Agent 6F, Bunzan Hill, 4-31-6, Shinbashi, Minato-ku, 105 Higashi J Nibu Part 6 of the detailed description of the invention by Mr. Hiroshi. (2) On page 7, line 19, ``It is easy to tear in the width direction.'' is corrected. ``Because it is weak in the width direction, it is easy to tear in the longitudinal direction (as shown in Figure 3).'' (3) In the 16th line of the 8th member, ``Because it is easy to tear in the +1 direction,'' is changed to the following standard. Correct. [Because it is weak in the width direction, K" easily tears in the longitudinal direction,
"that's all

Claims (2)

[Claims] (1) In a coaxial cable in which an insulator, an outer conductor, and an insulating sheath are sequentially provided around the outer periphery of a center conductor, a uniaxially stretched plastic Teso layer that is uniaxially stretched in the longitudinal direction connects the outer conductor and the insulator. A coaxial cable characterized by being provided between. (2) The coaxial cable according to claim 1, wherein the -axially stretched plastic tape layer is laminated on the outer conductor to form a fuminate tape structure.