FR2780209A1 - Sealing device for cables at entry to underground connection box - Google Patents

Abstract

The seal uses several stacked elements to offer range of sizes.- DETAILED DESCRIPTION - The cable connection system includes a connection box comprising at least two parts. These are separated by a flat sealing joint. The box includes a number of ports for input/output cables. Each of these ports includes a cylindrical elastomer sleeve (1) for the passage of a cable. The sleeve is made up from several concentric adapters (2,2',2.. 3) fitting together and retained by friction. The external diameter of one matches the internal diameter of the next in the series, and each includes a projecting rim (6) at its outer end. The sleeves may be compressed longitudinally between two flat washers, and this longitudinal compression increases the radial grip provided by the elastomer material

Description

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  The present invention relates to cable connection devices in which the connection area is protected by an enclosure that can, when you want to change the way cables are connected, then open and close. It applies in particular to underground connections of electrical or optical cables, for energy distribution networks and for

communication networks.

  These enclosures are subject to particularly rigorous specifications, since they must, after installation at the place of use, not only firmly maintain the cables despite the various pressures experienced by the enclosure as well as by the cables on the periphery of the enclosure, but also ensure sealing against liquid elements or dust likely to enter the enclosure and

  damage the connection area.

  The currently known connection devices comprise a rigid box consisting of a bottom and a cover. The cables to be connected are individually inserted into holes provided in the side walls of the bottom of the box, then connected to the inside of the box. Sealing at each input / output port is ensured, for example, by means of a heat-shrinkable seal enclosing the cable passing through said port. Modern cables are often made up of a bundle of filaments or fibers, enclosed in an overall outer sheath. However, the case frequently arises where a "stitching" must be carried out on a stretched cable, that is to say a diversion of only a part of these filaments or fibers, at a location in the cable that does not yet have any connection. Unless this location is located very close to one end of the cable, known devices do not allow this operation to be carried out while respecting the overall structure of the cable since, in order to be able to install such a connection box, one is forced to

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slice the cable.

  Another drawback of the devices according to the prior art is that the manipulations required to modify the connections (an operation often necessary in practice) are numerous and tedious. When you want to change the number or the arrangement of cables to be connected and you don't have the necessary holes on the old box, you have to change them, which forces you to undo all the existing connections, remove all the cables from the box, then perform all the connection operations again with the new box. These manipulations are also painful from a mechanical point of view in all applications, important from an industrial point of view, where said cables are not cables.

  flexible, but have a semi-rigid core.

  The present invention solves these problems by means of a device making it possible to install a connection box, or to change it, without having to interrupt the existing connections, while maintaining a watertightness of

  high level once the box is closed.

  The cable connection device according to the invention comprises a box comprising at least two parts separated by a flat seal placed around the periphery of the box but interrupted at the locations of the input / output ports, each of these ports being materialized by notches facing each other on said box parts

  and being filled with a bushing joint.

  These crossing joints are arranged, in a conventional manner, so as to enclose each cable in a sleeve preferably made of elastomer and preferably of essentially cylindrical shape, pierced with a number of longitudinal passage holes provided for an equal number of cables using the input / output port considered. For sealing purposes, the bushing seal compresses the cables

  radially when we close the box.

  According to the invention, it is provided that the technician, at the place of installation, can practice, on any sleeve

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  for which this operation is useful as a function of the particular needs of the connection considered, a slot in a plane containing a generator of the sleeve and the axis of a cable passage hole, in order to introduce a cable into said passage hole, or to withdraw a cable from it, laterally without having to thread said cable along said passage hole, and therefore without having to interrupt any existing connections. The material constituting the sleeve is chosen so that the operation can be carried out easily, on the one hand being tender enough to be able to be split by means, for example, of a simple cutter, and on the other hand fairly flexible to allow a gap between the lips of the slot sufficient to leave

pass the cable.

  The installer will do this, for example, to tap on a stretched cable, the latter then passing through the connection box passing through two ports.

  opposite input / output, without being sliced.

  The installer can also do this when he has to connect a new cable to a preexisting connection area, and when the box previously used does not have a free passage hole. On the new box, the installer can possibly thread the new cable along the corresponding passage hole without splitting the sleeve, but the slitting operation will facilitate the

  handling, especially if the new cable is semi-rigid.

  According to particular characteristics, each of these passage holes is, before installation of the device, like an assembly of concentric nested adapters, having a section of shape identical to that of the cable for which said passage hole is intended, so as to allow the installer to select the most suitable passage diameter for that of said cable simply by

  removing unnecessary interior adapters.

  According to other particular characteristics, each of said adapters has a lip which slightly increases the diameter of the adapter at its end.

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  external (compared to the connection box), and a lip which slightly reduces the diameter of the adapter

its inner end.

  According to still other particular characteristics, a certain number of longitudinal blind holes are drilled on

  the periphery of the inner base of the sleeves.

  According to additional specific characteristics, each of said sleeves is compressed longitudinally by means of two washers applied to the bases of the cylinder formed by said sleeve on the periphery of said bases, and held by means of screws passing through the joint longitudinally. These washers are in fact each made up of two half-washers in order to allow their application on the sleeve after the

place cables.

  According to other additional specific characteristics, the longitudinal passage holes for said tightening screws of the washers on the bushing joints have a section which narrows from the longitudinal ends of the hole towards the middle part.

  of the hole, in order to improve the tightness of said screw passage.

  Other benefits, purposes and features of

  the invention will emerge from the following description of

  some particular embodiments of the invention

  presented here as examples, this description

  based on the attached schematic drawings, in which: - Figure 1 is a perspective view of a bushing according to the invention, provided with a single cable passage hole and a series of concentric adapters illustrated here in the "deployed" position, - Figure 2 is a longitudinal section of the bushing illustrated in Figure 1, this time showing said concentric adapters in the "retracted" position, - Figure 3 is a simplified perspective view of the bushing illustrated in FIG. 1, showing two compression washers and one of the fixing screws

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  associated, - Figure 4a is an end view of the internal face of a crossing joint according to the invention provided with a single cable passage hole, - Figure 4b is similar to Figure 4a, if this is only the bushing illustrated shows two cable passage holes, and figure 4c is similar to figure 4a, except that the bushing illustrated illustrated has four holes

cable passage.

  The bushing shown in Figure 1 includes an approximately cylindrical sleeve 1 and several concentric adapters 2, 2 ', 2 ", ..., 3, which hold tightly together due to the frictional forces arising on the surface of the material whose there is a slight overlap in the diameters, internal for one and external for the other, of each pair of successive adapters. The smallest adapter 3 is extended by an even smaller diameter cylinder 4, the end of which is closed by a bottom 5. The installer can thus choose:

  - use an assembly of adapters (2, 2 ', 2 ", ....

  3) as is for a cable passage hole that it wishes to plug, that is to say through which no cable will pass, or else - cut the bottom (5) to place a cable of very small diameter in the through hole, or - remove one or more adapters 2, 2 ', 2 ", ..., 3 starting with the smallest, until you get the right diameter, that is to say the most able to closely marry the

corresponding cable.

  In the figures, cable passage holes of circular cross-section have been shown, but other shapes suitable for the cross-section of cables can very well be produced.

considered.

  Figure 2 shows that each adapter 2, 2 ', 2 ", ....

  3 is provided with a lip 6 which slightly increases the diameter

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  of the adapter at its outer end, and of a lip 7 which slightly reduces the diameter of the adapter at its inner end. These lips considerably improve the seal provided by the bushing, because they allow the cable passage hole to deform

  uniformly around the latter.

  FIG. 3 shows how the sleeve 1 is sandwiched longitudinally between two washers, one external 8 and the other internal 9, which are pressed against the body of the sleeve 1 by means of screws 10. This longitudinal compression results in radial expansion sleeve 1, which has the effect of pressing the surfaces both inwardly against the cables, and outwardly against the box. We thus obtain a substantial improvement

tightness of the device.

  The screw passage holes 11 pass through the sleeve 1 right through, while having a section which is not entirely constant; this indeed shrinks in the middle region 12 of the hole to improve it

sealing.

  In Figure 3, the body of the sleeve 1 has a slot 13 formed in a plane containing a generator and the axis of the cylinder. By twisting the body of the sleeve 1 so as to separate the lips from this slot 13, one can easily introduce a cable into its passage hole, or extract it. We also see on this figure the washers of

  compression 8 and 9, each of which is made up of two half

  washers. FIG. 4 shows that the internal face of the crossing joints is pierced with through holes 11 intended for the fixing screws 10 of the washers 8 and 9, cable passage holes in the central region of said faces, and peripheral blind holes 14. The latter have the effect of diffusing the compressive forces within the material of the bushing joint, which results in a more regular adhesion of said joint to the cables which pass through it, and

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  therefore an additional improvement in sealing.

  The multiple passage holes are useful for the connection of several cables, independent but arranged in a parallel geometry, between them or with other cables; they can also be used for tapping a cable making a loop in the connection box. It is obvious that the cable passage holes will not necessarily all have the same shape in cross section (and not necessarily a circular shape), or the same diameter as shown only by way of illustration.

example in Figure 4.

  Finally, it will be noted an additional advantage of the structure in concentric adapters of the cable passage holes, with regard to the numerous applications where the latter comprise a semi-rigid core. In fact, this structure ensures precise positioning of said cable cores, which makes it possible to accurately predict the positioning of their attachment points inside the

  junction box according to the invention.

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Claims (10)

  1. Cable connection device, characterized in that it comprises a box comprising at least two parts separated by a flat gasket placed on the periphery of the box but interrupted at the locations of a certain number of ports input / output, each of these ports being materialized by notches facing each other on said box parts and being filled by a crossing joint which compresses said cables radially when it is closed said box.   2. A cable connection device according to claim 1, characterized in that each of said through joints consists of a sleeve (1) preferably made of elastomer and preferably of essentially cylindrical shape, pierced with a number of through holes longitudinal provided for an equal number of cables using   the input / output port considered.   3. Cable connection device according to claim 2, characterized in that each of said passage holes is, before installation at the place of use of said device, as an assembly of concentric nested adapters (2, 2 ', 2 ", .... 3) having a cross-section identical in shape to that of the cable for which said through hole is intended, the smallest adapter (3) being extended by an even smaller diameter cylinder (4), the end is closed with a bottom (5).   4. Cable connection device according to claim 3, characterized in that each of said adapters (2, 2 ', 2 ", ..., 3) has a lip (6) which slightly increases the diameter of the adapter its outer end with respect to the connection box, and a lip (7) which slightly reduces the diameter of the adapter at its inner end, so as to make it more   uniform deformation of said cable passage holes.   5. Cable connection device according to one   any one of claims 2 to 4, characterized in that 9 - 2780209   the periphery of the internal base of the sleeves (1) is pierced with a number of longitudinal blind holes (14), in order to diffuse the compressive forces within the material of the bushing.   6. Cable connection device according to one   any one of claims 2 to 5, characterized in that   each of said sleeves (1) is compressed longitudinally by means of two washers (8, 9) which are applied to the bases of the cylinder formed by said sleeve (1) on the periphery of said bases, are held by means of screws (10) passing through the joint longitudinally, and are   each consisting of two half-rings.   7. A cable connection device for cable connection according to claim 6, characterized in that the longitudinal passage holes (11) for said clamping screws (10) of the washers (8, 9) on the bushing joints have a section which narrows from the longitudinal ends of the hole towards the middle part (12) of the hole.   8. Method for connecting cables by means of the device claimed in any one of   Claims 3 to 7, characterized in that the installer of said device can, as desired:   - use an assembly of adapters (2, 2 ', 2 ", ....   3) as is for a cable passage hole that it wishes to plug, that is to say through which no cable will pass, or else - cut the bottom (5) to place a cable of very small diameter in the through hole, or - remove one or more adapters (2, 2 ', 2 ", .... 3) starting with the smallest, until you get the right diameter, that is to say most apt to marry the corresponding cable.   9. Method for connecting cables by means of the device claimed in any one of   Claims 2 to 5, characterized in that the installer   of said device can practice, on any sleeve (1) for - 2780209   which this operation is useful according to the particular needs of the connection considered, a slot (13) in a plane containing a generator of said sleeve (1) and the axis of a cable passage hole in order to introduce a cable into said passage hole, or to remove a cable from it, laterally without having to thread said cable along said passage hole, and therefore without having to interrupt   any existing connections.   10. A method of connecting cables by means of the device claimed in claim 6 or claim 7, characterized in that the installer of said device can practice, on any sleeve (1) for which this operation is useful according to particular needs of the considered connection, a slot (13) in a plane containing a generatrix of said sleeve (1) and the axis of a cable passage hole, in order to introduce a cable into said passage hole, a cable, laterally without having to thread said cable along said passage hole, and therefore without having to interrupt any existing connections, and in that said installer screws the washers (8, 9) on said sleeve   (1) after installing the cables.