JP3181087B2 - Deformed leaky coaxial cable and its holding duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified leaky coaxial cable useful for communicating with a mobile terminal device in an underground space or a building, and a duct for holding the cable.

[0002]

2. Description of the Related Art An open coaxial cable or a leaky coaxial cable in which electromagnetic waves leak along a transmission line is used as a means for transmitting information to a terminal device such as a mobile phone or a paging device moving in a premises or a building. It is known.

FIGS. 6A and 6B are a sectional view and a side view of a leaky coaxial cable proposed by the present applicant.
Reference numeral 0 denotes a center conductor, and reference numeral 11 denotes an insulator surrounding the center conductor 10, which is formed of, for example, a dielectric resin.
Reference numeral 12 denotes an outer conductor that covers the outer periphery of the insulator. The outer conductor 12 has an opening 12A at a predetermined position for leaking electromagnetic waves. The position and the size or the number of the openings 12A are set in consideration of the frequency band to be used, the distribution of electromagnetic waves radiated in the building, and the like. Reference numeral 13 denotes a sheath provided to cover the outer periphery of the outer conductor 12, and as shown in a sectional view thereof, a square having a flat surface 13A obtained by cutting a part of the outer peripheral surface of the sheath 12. It has been.

The flat surface 13A is set at a position opposing the opening 12A. Therefore, this modified leaky coaxial cable can recognize the side surface where the opening 12A is formed from the outside of the sheath 13. Also, as shown in FIG. 3B, a mark 14 is formed on the outer periphery of the sheath 12 where the opening 12A is located.
By printing, the position of the opening can also be known in the longitudinal direction of the cable. Since this leaky coaxial cable is provided with a flat portion 13A at a part of the outer periphery of the sheath 13 and has an irregular cross section, if the flat portion 13A is laid so as to be in contact with a floor surface in a building or a ceiling surface,
Since the opening 12A of the cable is located on the space side in the building, leakage of the electromagnetic wave is efficiently performed.

[0005]

Since the leaky coaxial cable is configured so that the outer peripheral surface is non-circular, the following disadvantages are observed. (1) The connector for connecting the coaxial cable is
Usually, since the cable introduction part is formed in a perfect circular shape, when connecting the above-described leaky coaxial cable with a connector, at least a sheath portion of 3 to 5 cm from the connection end is made to be a perfect circle with a knife or the like. It is necessary to perform a cutting work, which significantly reduces the efficiency of the connection work. (2) If any irregularities remain on the cut surface of the sheath, the waterproof function of the plug becomes extremely poor and the transmission loss is reduced. (3) Hand cutting is not preferable from the viewpoint of aesthetics.

[0006]

According to a first aspect of the present invention, a center conductor, an insulator surrounding the center conductor, and an outer periphery of the insulator are covered with a predetermined size in the longitudinal direction of the cable. An outer conductor having an opening formed along the outer conductor, and a sheath covering the outer side of the outer conductor, wherein the sheath has a first coating layer having a circular cross section; A second coating layer formed on the outer peripheral surface of the coating layer and having a different cross section with a material different from that of the first coating layer, and the position of the opening and the second coating layer having the different cross section Are configured to correspond in a predetermined positional relationship.

According to a second aspect of the present invention, the irregular cross section is constituted by two convex bands, and the convex bands can be easily deleted.

A third aspect of the present invention is a holding duct for laying a leaky coaxial cable having a deformed section in advance on a ceiling or a floor surface so as to facilitate the cable laying operation. Is provided.

[0009]

The outer shape of the sheath can be arranged so that the leakage direction of the electromagnetic wave is concentrated only in a specific direction during the laying work, and also when the cable is connected to the connector. It is possible to easily return the outer shape to a perfect circle.

[0010]

FIG. 1 is a perspective view of a leaky coaxial cable according to the present invention.
Is formed of, for example, a dielectric plastic material.

Reference numeral 22 denotes an outer conductor which covers the outer periphery of the insulator 21. The outer conductor 22 has openings 22A for leaking electromagnetic waves at predetermined intervals or continuous spaces.
The lot is formed along the longitudinal direction of the cable. Reference numeral 23 denotes a first coating layer (sheath) provided to protect the outer conductor 22, and is formed by, for example, extruding and coating vinyl chloride (PVC). Reference numeral 24 denotes a second coating layer applied to the outer surface of the first coating layer (sheath) 23 by extrusion or the like, and the outer shape of the second coating layer 24 is a non-circular irregular cross section. It has been. That is, in the case of this embodiment, the flat surface 24A is formed on the opposite side of the opening 22A. Further, the second coating layer 24 is formed of the first coating layer 24.
, A material different from the coating layer 23, for example, polyethylene (P
E).

In the leaky coaxial cable according to the present invention, as described above, the sheath portion attached to the outer peripheral side has the second coating layer 2 having an irregular cross section with the first coating layer 23 having a circular cross section.
4, it is possible to easily set the direction of the electromagnetic wave leaking from the leaky coaxial cable as shown in the prior art, and at the same time, for example, as shown in FIG. When the end face of the leaky coaxial cable of the present invention is connected to the plug C, a cut is made from the surface of the second coating layer 24 along a two-dot chain line A, B with a knife or the like, and cut out in the direction of the arrow. The second coating layer can be removed while leaving the coating layer 23, and the outer surface of the portion to be inserted into the plug C can be extremely easily processed into a circular shape.

In the above embodiment, the sheath portion of the leaky coaxial cable is formed of two coating layers. The irregular cross-section simply showing the opening on the radio wave leak side is as shown in FIGS. In addition, convex bands 25A and 25B may be provided on the side of the outer conductor 22 opposite to the opening 23A. in this case,
Convex bands 25A, 25 extending in the longitudinal direction of the cable
B can be easily cut off from the end face of the cable by a predetermined length with a knife, and the sheath at the end of the cable can be easily processed into a circular shape. Therefore, similarly to the embodiment shown in FIG. There is an advantage that connection work is facilitated.

FIG. 5A shows a cross section of a cable holding duct according to a third embodiment of the present invention.
Holding duct 30 made of plastic extrusion molding or the like
Is a pair of support portions 30 rising from both sides of the flat portion 30A and the flat portion 30A, and curled inward in the tip direction.
B, 30C. Flat part 30A and support part 30
The internal space surrounded by B and 30C is configured to substantially match the outer peripheral shape of the above-described deformed leaky coaxial cable. This cable holding duct is fixed to the floor or ceiling by double-sided adhesive tape attached to the bottom surface of the flat portion 30A, or by screwing both ends of the flat portion 30A, and the like, as shown in FIG. As can be seen, after the elastic supporting portions 30B and 30C are opened, a cable OC having an irregular cross section can be inserted and laid at a predetermined position.
In this case, since the electromagnetic wave leaking from the cable OC is set in the direction of the thick arrow, there is an advantage that the radiation direction of the radio wave is always in a fixed direction, and the installation work is easy.

[0015]

As described above, the leaky coaxial cable of the present invention can be installed so that the position of the opening for leaking radio waves is always in a fixed direction due to the outer shape of the sheath portion having an irregular shape. For example, by laying the cable such that the flat surface becomes the reference surface of the floor or ceiling, there is an effect that the cable can be easily laid such that the radio wave radiation direction faces the communication terminal side. Also, when connecting the leaky coaxial cable having the irregular cross section to the connector, the sheath outer shape can be easily processed into a circular shape, so that there is an advantage that the efficiency of the installation work is improved. Further, by using the holding duct of the present invention, a leaky coaxial cable having an irregular cross section is efficiently laid along the wall surface and floor surface of the building, and furthermore, the radiation direction of the radio wave is directed to the building space side. be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view and a side view of a leaky coaxial cable according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of circular processing of a cable end face.

FIG. 3 is a sectional view of a leaky coaxial cable showing another embodiment of the present invention.

FIG. 4 is a sectional view of a leaky coaxial cable showing another embodiment of the present invention.

FIG. 5 is a sectional view of a holding duct that can be used when laying the leaky coaxial cable of the present invention.

FIG. 6 is a sectional view and a side view of a modified leaky coaxial cable showing the prior art of the present invention.

[Explanation of symbols]

 Reference Signs List 20 center conductor 21 insulator 22 outer conductor 22A opening 23 first covering layer 24 second covering layer 25A, 25B convex band 30 holding duct

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsutomu Oshima 1-16-10 Dogenzaka, Shibuya-ku, Tokyo Inside the Japan Ocean Submarine Electric Cable Co., Ltd. (56) References JP-U 4-31810 (JP, U) ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 3/06 H01B 11/18 H01P 3/00

Claims (3)

(57) [Claims] A center conductor, an insulator surrounding the center conductor, an outer conductor covering an outer periphery of the insulator and having an opening formed along a predetermined size in a longitudinal direction of the cable; A first coating layer having a circular cross section, and a material different from the first coating layer on an outer peripheral surface of the first coating layer; A second covering layer having an irregular cross section,
A deformed leaky coaxial cable, wherein the position of the opening and the deformed plane of the second coating layer having the deformed cross section correspond to each other in a predetermined positional relationship. 2. A center conductor, an insulator surrounding the center conductor, an outer conductor covering an outer periphery of the insulator and having an opening formed along a predetermined size in a longitudinal direction of the cable, A sheath covering the outside of the outer conductor; and a part of an outer peripheral surface of the sheath on the opposite side of the opening.
A deformed leaky coaxial cable, characterized in that two protruding strips projecting in the radial direction of the center conductor are provided, and the two protruding strips are formed so as to be easily removed . 3. A flat portion, and two support portions rising from both sides of the flat portion and bending inward, and a space surrounded by the flat portion and the two support portions is the patent. A duct for holding a deformed leaky coaxial cable, wherein the duct is formed so as to substantially conform to the outer shape of the deformed leaky coaxial cable described in claim (1) or (2).