JPH07120626A - Cable connecting box - Google Patents

Abstract

PURPOSE:To provide a cable connecting box with desirable watertightness and airtightness. CONSTITUTION:In the cable connecting box of approximately quadrangular cross section with half-sleeves 11 divided into two in the longitudinal direction of a cable and fastened by bands 12, a protrusion 13 is interposed between the half-sleeve 11 and the band 12, in the vicinity of the nearly center part of the fastening part of the band 12 on the periphery of the half sleeve 11, and the fastened band 12 presses the half-sleeve 11 with the protrusion 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cable connection box used for a connecting portion such as an optical fiber cable.

[0002]

2. Description of the Related Art It is necessary to prevent water and moisture from entering a connecting portion such as an optical fiber cable. Therefore, a cable connection box (closure) having a sealing function is used to protect the cable connection portion. Since the cable junction box needs to be opened and closed for reconnection, mechanical seals that can be mechanically assembled and have good workability are mainly used. A conventional mechanical seal type, for example, a band fastening type cable connection box is shown in FIG.
It has the structure shown in FIG. This cable junction box
The two half sleeves 1 are made of a box having a substantially quadrangular cross section in which side end cross sections are joined so as to face each other. The two half sleeves 1 have packing grooves on both end cross sections, and are fastened with a metal band 3 via the packing 2 to form a watertight and airtight box. 4 is a band fastener.

[0003]

However, the above cable connection box has the following problems. That is,
When the band 3 is fastened, the band 3 tries to be circular,
In order to apply pressure to the side surface of the sleeve, the box cross section of the substantially quadrangle is concave on both side surfaces as shown in FIG. Since you can only apply force, between A and B, C
The area between -D tends to swell and become circular. As a result, as shown in FIG. 4, the packing 2 at the joint of the half sleeve 1 did not sufficiently function, and there was a risk of causing a gas leak. Therefore, if the wall thickness of the half sleeve is increased to increase the rigidity in order to suppress the deformation of the half sleeve, there is a problem that the weight of the box increases.

[0004]

SUMMARY OF THE INVENTION The present invention provides a cable connection box which solves the above-mentioned problems. It has a substantially rectangular cross section and is divided into two halves in the longitudinal direction of the cable. In the cable connection box in which the band is fastened with a band, a convex object is interposed between the half sleeve and the band near the center of the band fastening portion on the circumference of the half sleeve, and the fastened band is the convex object. The first invention is to press the half sleeve with, and the second invention is that the band is provided with a convex object in the above invention. In the cable connection box with the above structure, when assembling the sleeve, during the process of tightening the half sleeve with the band, the band directly presses the half sleeve at the corners of the four corners, and the half sleeve is pressed through the convex object. Since the sleeve is pressed from the outside to the inside, the half sleeve does not bulge outward and the box cross section is not deformed into a circular shape. Therefore, even if the half sleeves are fastened with the band, the packing of the joints of the half sleeves sufficiently functions, and the watertightness and airtightness can be secured. Although the present invention is applied to a sleeve whose cross section is substantially quadrangular, the meaning of substantially quadrangular means that when the band is fastened, the band exerts pressure on the four corners of the sleeve, and the substantially central portion of the half sleeve is This means that the half-sleeve swells outward because no pressure is applied.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a cross-sectional explanatory view of an embodiment of a cable junction box according to the present invention. In this embodiment, a half sleeve 11 made of half a substantially rectangular tube made of fiber reinforced polypropylene is attached to a stainless steel band 12.
It is formed by fastening. The band 12 has a convex-shaped object 13 at a portion located substantially in the center of the circumference of the half sleeve 11.
Is provided. 14 is packing and 15 is a band fastener. FIGS. 2A and 2B are a front view and a side view of the band in a fastened state, respectively. The band 12 presses the half-sleeve 11 inward with the convex member 13 to prevent the half-sleeve 11 from expanding outward and becoming circular. The convex object is not necessarily provided on the side of the band facing the half sleeve, and may be simply interposed between the band and the circumference of the half sleeve. Further, it goes without saying that the shape of the half sleeve is not limited to the above embodiment and may be a half ellipse or the like.

[0006]

As described above, according to the present invention, in a cable connection box having a substantially rectangular cross section and a half sleeve divided in two in the longitudinal direction of the cable is fastened with a band, the half sleeve is used. A convex object is interposed between the half sleeve and the band near the center of the band fastening portion on the circumference of the sleeve, and the tightened band presses the half sleeve with the convex object. The packing of the seams works well and has the excellent effect that there is no risk of gas leaks.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a cable junction box according to the present invention.

2A and 2B are respectively a front view and a side view of a band in a fastened state in the above embodiment.

3A and 3B are a side view and a sectional view of a conventional cable junction box, respectively.

FIG. 4 is an explanatory view of problems of the conventional cable connection box.

[Explanation of Codes] 11 Half Sleeve 12 Band 13 Convex Object 14 Packing 15 Band Fastener

Front page continued (72) Inventor Takashi Kawamura 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (2)

[Claims] 1. A cable connection box having a substantially rectangular cross section and having a half sleeve divided in the longitudinal direction of the cable fastened by a band, in the center of a band fastening portion on the circumference of the half sleeve. A cable connection box characterized in that a convex object is interposed between a half sleeve and a band in the vicinity, and the tightened band presses the half sleeve with the convex object. 2. The cable junction box according to claim 1, wherein the band is provided with a convex object.