JPH0726806U - Cable junction box - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a cable junction box that is watertight and airtight. In a cable connection box having a substantially rectangular cross section and fastening a half sleeve 11 divided into two in the longitudinal direction of a cable with a band 14, the divided half sleeve 11 is a band on the circumference. The fastening band 14 has a convex portion 12 near the center of the fastening portion, and the fastened band 14 presses the half sleeve 11 divided by the convex portion 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a cable connection box used for a connecting portion such as an optical fiber cable.

[0002]

[Prior art]

 It is necessary to prevent water and moisture from getting into the connections such as optical fiber cables. Therefore, a cable connection box (closure) with a sealing function is used to protect the cable connection. 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, band fastening type cable connection box has a structure shown in FIGS. 4 (a) and 4 (b). This cable connection box is composed of a box having a substantially rectangular cross section in which two half sleeves 1 are joined so as to face each other in a side end cross section. The two half sleeves 1 have packing grooves on both side end sections, and are fastened with a metal band 3 through a packing 2 to form a watertight and airtight box. 4 is a band fastener.

[0003]

[Problems to be solved by the device]

 However, the above-mentioned cable connection box has the following problems. That is, when the band 3 is fastened, the band 3 tends to become circular and exerts pressure on the side surface of the sleeve, so that the box cross section of the substantially rectangular box is dented on both side surfaces as shown in FIG. When the four corners are A, B, C, and D, the force can be applied only to these four corners, and therefore there is a tendency that a space between A and B and a space between C and D swell to form a circle. As a result, as shown in FIG. 5, the packing 2 at the joint of the half sleeve 1 did not fully 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]

[Means and actions for solving the problem]

 The present invention provides a cable connection box that solves the above problems, and has at least a rectangular cross section, and at least a cable connection box in which a half sleeve divided in the longitudinal direction of the cable is fastened with a band. One of the half sleeves has a convex portion near the center of the band fastening portion on the circumference, and the fastened band presses the half sleeve with the convex portion. In the cable junction box with the above structure, the band presses the half sleeves at the four corners while tightening the half sleeves with the band when assembling the sleeve. Since the split sleeve is pressed, the half sleeve does not bulge outward and the box cross section does not deform circularly. Therefore, even if the half sleeves are fastened with a band, the packing of the joints of the half sleeves functions sufficiently and there is no risk of causing a gas leak. Although the present invention is applied to a sleeve having a substantially square cross section, the meaning of a substantially square means that when the band is fastened, the band exerts pressure on the four corners of the sleeve, so that the band is approximately centered on the half sleeve. Means that the half-sleeve swells outward because no pressure is applied.

[0005]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a perspective view of a half sleeve used in an embodiment of a cable junction box according to the present invention. The half sleeve 11 of this embodiment is a half of a substantially rectangular tube made of fiber reinforced polypropylene, and a convex portion 12 is integrally formed on the upper surface at a substantially central portion of a band fastening portion. Reference numeral 17 is a rib that prevents the band formed on the surface of the sleeve 11 from being displaced, and 13 is an end plate made of synthetic rubber. FIG. 2 is a sectional view of a cable connection box formed by fastening the half sleeve 11 with a stainless band 14. The band 14 presses the half sleeve 11 inwardly by the convex portion 12 to prevent the half sleeve 11 from expanding outward and becoming circular. 15 is a packing, and 16 is a band fastener. FIG. 3 is a cross-sectional view of another embodiment. In FIG. 3, one half sleeve 21a has a semi-cylindrical shape, and the other half sleeve 21b is a half of a substantially rectangular tube. In this embodiment, when the band 14 is fastened, the half sleeve 21a has a semicircular cross section and is convex outward, and the band is pressed. Therefore, it is not necessary to form a convex portion. Therefore, the protrusion 22 may be formed only on the half sleeve 21b. In the present invention, 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]

[Effect of device]

 As described above, according to the present invention, at least one of the above-mentioned half-splits is provided in a cable connection box in which a transverse section has a substantially quadrangular shape and a half-split sleeve divided in the longitudinal direction of the cable is fastened with a band. The sleeve has a convex part near the center of the band fastening part on the circumference, and the fastened band presses the half sleeve with the convex part, so the packing of the seam of the half sleeve does not function sufficiently. As a result, there is an excellent effect that there is no risk of causing a gas leak.

[Brief description of drawings]

FIG. 1 is a perspective view of a half sleeve used in an embodiment of a cable junction box according to the present invention.

FIG. 2 is a cross-sectional view of the above embodiment.

FIG. 3 is a sectional view of another embodiment according to the present invention.

4A and 4B are a side view and a sectional view of a conventional cable junction box, respectively.

FIG. 5 is an explanatory view of problems of the conventional cable connection box.

[Explanation of symbols]

 11, 21a, 21b Half sleeve 12, 22 Convex portion 13 End face plate 14 Band 15 Packing 16 Band fastener 17 Rib

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

Claims (1)

[Scope of utility model registration request] 1. A cable connection box having a substantially quadrangular transverse cross section, wherein a half sleeve divided in two in the longitudinal direction of the cable is fastened with a band, at least one of the half sleeves having a circumferential band fastening. A cable connection box characterized in that it has a convex portion near the center of the portion, and the tightened band presses the half sleeve with the convex portion.