Cable junction box

#The invention is directed to a cable junction box for connecting or branching cables, especially communication cables, with a longitudinally divided socket tube with locking-sections bounding the longitudinal division. Sealing members are embraced by the tubular box for closure or sealing of its ends, with the sealing members comprising cable passages adaptable to different cable diameters. Also, peripheral or circumferential seals are disposed in circular locating grooves between the socket tube and the sealing members.

#With such cable junction boxes, which as a rule are laid underground, a sound seal of the socket tube against the sealing member must naturally be achieved. On the one hand, peripheral seals are provided for this purpose and, on the other hand, the socket tube is clamped together not only in the region of the longitudinal division by one more closure clamps which under- and overlap the closure sections, but they also exert clamping forces on the sealing member in order to press the peripheral seals into their locating grooves. Since the socket tube is fabricated out of a plastic sleeve of comparatively small thickness, for instance 4 mm, excessive elongation or expansion and a widening resulting therefrom cannot be excluded during application of a clamping force upon the sealing members. Such an excessive elongation or widening can, however, lead to an impairment of the sealing of the socket tube against the sealing member.

#Accordingly, it is an object of the present invention to provide a cable junction box for connecting and branching cables, in particular communication cables, of the previously described type, where an excessive elongation and final widening of the socket tube is prevented in the course of closing the tube to obtain a sound seal of the socket tube against the sealing member.

#Fig. 1 shows a cable junction box pursuant to the invention, diagrammatically in axial section;

#FIG. 2 is a diagrammatic front view of the junction box of FIG. 1;

#FIGS. 3 is a cross-section through the tubular box in the longitudinal division region;

#A cable junction box 1 for connecting and branching cables 2, especially communication cables, is shown in the figures. In its basic construction the box 1 comprises a longitudinally divided socket tube 3 of plastic material, and locking sections 4 bounding the longitudinal division. Sealing members 5 are embraced by the socket tube 3 for end face closing of the socket tube 3 and have cable passages 6 adaptable to different cable diameters, and peripheral seals 8 that are pressable into circular location grooves 7 between the socket tube 3 and the sealing members 5. The closure of the socket tube 3 is achieved by means of closure clamps 9 overlapping and underlapping the closing sections 4, so that the socket tube 3 is not only clamped in the region of its longitudinal division, but compressive stress is also exerted upon the sealing members 5 and consequently upon the peripheral seals 8, as well as compressive stress being exerted upon the sealing members 5 and the peripheral seals 8 from all directions. In order to avoid an over-extension or widening of the plastic socket tube 3, which might result from the above-mentioned clamping, the socket tube 3 comprises a circular jacket reinforcement 10 that extends in the region of both ends of the tube up to the area of the longitudinal division The jacket reinforcements 10 are configured as material thickenings of predetermined width B and thickness S and they axially protrude on both sides beyond peripheral seals 8.

#In a preferred embodiment, the width B of the jacket reinforcement 10 amounts to approximately 50 mm and its thickness S to approximately 2 mm, so that a 4 mm thick socket tube 3 has an overall thickness of 6 mm in the region of the jacket reinforcement 10. Naturally other dimensions can also be chosen. The reinforcements 10 are configured as external moldings and can therefore be easily fabricated.

#For closing the longitudinal division itself, a groove-spring connection 11, 12 having a U-shaped grooved section 11 for receiving a longitudinal seal 13 is provided at one tension or butt-edge, and a spring section 12 engaging into the grooved section at the other butt edge of the longitudinal division for compressing the longitudinal seal 13. The closure- and compression forces are produced by the closing clamp 9.