FR2606945A1 - Device for connecting conducting cables possessing a metal sheath for sealing or for screening - Google Patents

Abstract

Device for connecting conducting cables possessing a metal sheath for sealing or for screening against electromagnetic inductions. This device includes, for each metal sheath 5, 5a to be connected, an elementary connection system 9, 9a formed by the combination of an inner metal bush 12 engaged beneath the end of this sheath around the end of the corresponding conductor or conductors 3, and of two outer metal half-shells 13 clamped around the end of this same metal sheath 5, 5a and around its insulating outer jacket 6 by being placed in contact with a collar 14 carried by the inner metal bush 12. The present device comprises, on the one hand, one or two metal connecting sleeves 10, 10a attached respectively to one and to the other of these two connection systems and which are suitable for forming a screening cage around the ends of the conductor or conductors of the corresponding cables. The present device can be used in all cases where the cables to be connected include a metal screening sheath.

Description

"Connection device for
conductor cables with a metallic sheath
sealing or shielding "
The present invention relates to devices intended to ensure the connection of conductive cables having a metallic sheath for sealing or shielding against electromagnetic induction. This is particularly the case of conductive cables used in telecommunications as well as certain cables of electrical conductors and screened conductors for computer equipment. For cables of this kind, it is therefore necessary not only to ensure the connection of the conductor (s) existing in one and the other of the ends to be connected, but also the connection of the metal sheaths of one and the other of these two ends.

 To this end, a number of devices have already been proposed specially designed for such a connection.

 Thus the French utility certificate 2,488,066 describes a device comprising two elementary connection systems intended to be attached to one and the other of the ends of the cables to be connected and which are connected together by a connecting conductor. Each of the elementary connection systems comprises contact blades intended to pass, by heating it, the outer insulating envelope of the corresponding metallic sheath for shielding or sealing in order to come into direct contact with this sheath. As for the various conductors of the corresponding ends of the two cables, they are connected to each other by other suitable connection means.

The solution thus provided provides a conductive connection between the metal sheaths of the two ends of cables to be connected. However, this connection is precarious over time. In addition, there is an interruption in the peripheral shielding and sealing screen formed by the metal sheath of the cables thus connected. However, studies carried out on radioelectric or other disturbances, for example the effect of lightning or IEMN disturbances (Impulses
Nuclear electromagnetic) have shown that it is imperative to avoid any interruption of the peripheral shielding screen to avoid "illumination" of the transmission conductors.

 The other connection devices currently used are also incapable of ensuring the continuity of the peripheral protection of the transmission conductors. This is notably the case for the device described in patent application FR 2,578,694. Again, the corresponding device simply provides a conductive connection between the shielding sheaths of the two ends to be connected, but without achieving continuity of the peripheral protective screen formed by these sheaths.

 This is why the present invention aims to achieve a connection device which is designed so as to ensure continuity of the peripheral shielding screen formed by the metal sheaths of the two ends of cables connected by this device and this, all around the transmission conductor (s) which are themselves connected by any other suitable connection means.

To this end, the connection device according to the invention is characterized in that it comprises
- on the one hand, for each metallic sheath to
connect, an elementary connection system
consisting of the combination of a socket
internal metal likely to be engaged under
the end of this sheath around the end
the corresponding conductor (s), and two
external metal half-shells intended for
to be tight around the end of this same
metal sheath and its outer casing
insulating, by suitable means of assembly,
by being placed in contact with a collar
carried by the internal metal sleeve and which
located outside the end of the
metal sheath
- on the other hand one or two metal sleeves of
connection likely to be reported on
either of these two connection systems
and which are able to constitute a cage of
shield around the end connections of the
or corresponding cable conductors.

 Indeed there is a conductive connection of this or these sheaths with the metal shielding sheath of the end of one and the other corresponding cables.

This connection is achieved by the fact that these sleeves are in contact with the two half-shells of each corresponding elementary connection system and that the latter are themselves in contact with the flange carried by the internal metal sleeve of this same system. However, this socket is in close contact with the end of the corresponding metal sheath since it is engaged inside the latter and the two corresponding half-shells are tightened around the assembly. We thus obtain in this way a complete continuity of the peripheral protection screen which must extend all around the transmission conductor (s) to be connected to avoid electromagnetic disturbances (radioelectric, IEMN, HF, etc.) by direct illumination of the transmission conductors.

 Preferably, the connection between the two elementary connection systems is ensured by two metal sleeves respectively mounted around the external half-shells of one and the other of these elementary systems and which are capable of being fitted one into the other. Each of these sleeves is advantageously constituted by two half-sleeves fixed one and the other on the two corresponding external half-shells, for example by means of assembly screws. In such a case, the joint plane of these two half-sleeves is advantageously angularly offset from that of the two corresponding half-shells.

However, other characteristics and particularities of the connection device according to the invention will appear during the following description of a few exemplary embodiments of this device. This description is given with reference to the attached drawing for information only, and on which
Figure 1 is a perspective view of a connection device according to the invention ensuring the connection of two cables having a single axial transmission conductor.

 Figure 2 is a similar view showing another embodiment of this device which is designed for the connection of two cables each comprising a bundle of multiple de-transmission conductors.

 FIG. 3 is a view in axial section of the connection device according to FIG. 1.

 FIG. 4 is a view in cross section along the line IV-IV of FIG. 3.

 Figures 5 and 6 are perspective views showing in isolation on the one hand the internal metal sleeve of an elementary connection system of this device and on the other hand the two corresponding external half-shells.

 Figure 7 is a partial view in axial section of an alternative embodiment of these half-shells.

 Figure 8 is an axial sectional view of another embodiment of each of the elementary connection systems forming part of the present device.

 Figure 9 is a cross-sectional view of one of the half-shells of this system.

 Figure 10 is a partial view in axial section of another embodiment of the half-shells provided in each elementary connection system.

 Figure 11 is an exploded perspective view which corresponds to this embodiment.

 Figure 12 is a partial view in axial section of yet another embodiment of each elementary connection system.

 Figure 13 is a schematic view in axial section of a detail, in this case a particular mode of connection of the connection sleeves of the two elementary connection systems.

 Figure 14 is a perspective view of one of the connecting cages provided in such a case.

 Figure 15 is a perspective view of yet another embodiment of the connection device according to the invention.

 Figure 16 is a sectional view of a detail of this device.

 FIG. 17 is a perspective view showing a connection member which can be used to ensure the individual connection of the different transmission conductors of two cables.

 Figure 18 is a partial perspective view of another embodiment of the device according to the invention.

 FIG. 19 is a view in axial section of an alternative embodiment of the external half-shells of an elementary connection system of this device, a variant in which these form one body with the corresponding connecting half-shells.

 Figure 20 is a partial view in axial section of yet another embodiment of the device according to the invention.

 Figure 21 is an axial sectional view of a particular use of a part of this device.

 As already indicated, the device according to the invention is intended to be used for the connection of two cables comprising a metal sheath for sealing or shielding against electromagnetic induction. I1 may be cables such as cables 1 and 1a, or 2 and 2a shown respectively in FIG. 1 and in FIG. 2. In the first case, a single axial conductor 3 of transmission is provided embedded in a flange 4 made of plastic placed inside a metal sheath 5, itself covered by an external envelope 6 made of plastic. In the second case the corresponding cable 2 contains a bundle of multiple conductive wires 7 of transmission placed at the inside an intermediate envelope 8, the assembly being disposed inside a metal sheath 5, itself covered by an external envelope 6 made of plastic.

 In either case there is always a metal sheath 5 for shielding or sealing which is covered by a tubular external envelope 6 made of plastic. This metal sheath can be made of aluminum or any other suitable metal and its thickness can be a few hundredths of a millimeter, this sheath being earthed at both ends. Such a sheath is then able to ensure a reduction in disturbances of about 70 decibels. However, the thickness of this shielding sheath can be notably increased, which has the advantage of increasing the effect of reducing disturbances.

 As shown in the sectional view of Figure 3, the connection device according to Figure 1 comprises two elementary connection systems designated by the general references 9 and 9a. Each of these is attached to the end of one of the two identical cables 1 and the to be connected, these two elementary connection systems being themselves connected by two external metal sleeves 10 and îOa which are nested one inside each other. These two sheaths thus form a peripheral shielding cage which completely surrounds the corresponding ends of the two conductors 3 and 3a of the cables 1 and 1a, which are connected by a separate connection member 11, of the appropriate type.

 Each elementary connection system comprises an internal metal sleeve 12 and two external half-shells 13. The internal sleeve 12 has a conical external profile and its dimensions are such that it can be engaged between the flange 4 of the cable 1 or the corresponding and the metal sheath 5 for shielding the latter, as shown in FIG. 3. This engagement is made possible by the conical profile of the external wall of this socket. Due to this engagement, this is in close contact with the corresponding metal sheath 5. At its end, which corresponds to its base, this socket has an external flange 14. This obviously remains outside the metal sheath 5 and its casing 6 when the corresponding socket is engaged inside of these.

 As for the two external half-shells 13, they are also made of metal, therefore conductive. Their dimensions are such that they can be added around the end of the metal sheath 5 and its casing 6 after an internal sleeve 12 has been engaged inside of them. To this end, the internal wall of these two half-shells has a conical profile over at least part of its length. At their end turned on the side opposite to the flange 14 of the internal sleeve 12, the two half-shells 13 have an external shoulder 15 of toroidal shape which has the aim of avoiding peak effects.

 During assembly, the opposite end of these two half-shells is placed in contact with the shoulder 14 of the corresponding internal sleeve 12. This therefore provides a conductive connection between these two half-shells and the shielding sheath 5. This connection can advantageously be reinforced by the addition of screws 46, or other suitable members ensuring the joining of the collar 14 of the internal sleeve with the two corresponding half shells, as provided in FIG. 8.

 As for these two half-shells, they comprise clamping means making it possible to fix them in place. They can be screws 45 carried by one of these two half-shells and which are screwed into the other. The tightening thus produced makes it possible to obtain perfect connection contact between the internal face of the metal sheath 5 and the corresponding internal sleeve 12.

 For the connection of metal sheaths 5, 5a of small thickness, the internal sleeve 12, may advantageously include an external annular rib 16 extending transversely. To this rib corresponds a groove 17 provided in the internal wall of the two half-shells 13. However, the depth of this groove is less than the projection formed by the rib 16. Under these conditions, when the two half-shells 13 are tightened, it produces in this place a stretching of the metal of the sheath 5 due to the deformation imprinted in this sheath by the rib 16. This is therefore likely to increase the contact surface by increasing the quality of the conductive connection existing between the sheath 5 and the inner sleeve 12.

 The corresponding metallic sheath 10 or lova is attached to each of the elementary connection systems thus formed. Each of these is actually constituted by two half-sleeves 18 attached around the two corresponding half-shells 13 and fixed thereon by means of a number of screws 19 arranged radially. These screws are engaged inside longitudinal slots 20 formed in the corresponding ends of the half-sleeves 18, which allows the axial adjustment of the position of the latter.

 After tightening, there is a close contact, therefore a conductive connection, between the contact surfaces of the two half-sleeves 18, as well as between the contact surfaces of the two half-shells 13. However, an offset is provided angular, for example 90, between the joint plane AB of the two half-sleeves 18 and the joint plane CD existing between the half-shells 13.

 Each of the outer sheaths 10 or îOa thus formed extends beyond the corresponding elementary connection system in the form of a projecting cylindrical part 21 or 21a. However, one of these two parts has a flare so that they can be fitted one inside the other as shown in Figure 3. At this location the two sleeves 10 and îOa are therefore in close contact with each other, which ensures the necessary conductive connection between the metal sheaths 5 and 5a of the two cables 1 and the one to be connected, since each of these sheaths is already in contact with the corresponding elementary connection system 9 or 9a. As already indicated, the projecting parts 21 and 21a of the two sleeves 10 and îOa constitute an absolutely continuous peripheral cage around the ends of the two conductors 3 and 3a of the two cables 1 and la. Under these conditions, the present connection device not only ensures a conductive connection between the two metal sheaths 5 and 5a, but also the continuity of the closed shielding screen at the corresponding location. However, this is essential to maintain a good quality of protection against various electromagnetic or other disturbances. On this subject it is interesting to note that an interruption of the shielding screen over a length of approximately 50cm can cause an increase in the induced voltage of the order of 30dB, even if this screen is not electrically isolated.

 Preferably, the projecting parts of the sleeves 10 and 10a are fixed to one another by means of a number of radial screws 22 engaged in longitudinal slots 23 of one of these parts. In addition, a sleeve 24 made of heat-shrinkable plastic is then added to seal the assembly.

 The connection device shown in Figure 1 is designed for connecting cables with a single conductor, or a limited number of conductors. As for the device of FIG. 2, it is intended for the case of cables comprising a bundle of numerous conductors. The device differs from that of FIG. 1 only by a modification of the shape of the projecting parts 21b and 21c of the two corresponding external sheaths lOb and vioc. Indeed, these projecting parts are both flared so as to form a cage of larger diameter around the connections made between the ends of the multiple conductors 7 and 7a of the two corresponding cables 2 and 2a. This is also essential given the multiplicity of these various connections. These are produced individually by means of all appropriate systems. Optionally, it is possible to use a connection plate 25 such as that shown in FIG. 17. This part comprises a series of bores 26 intended to receive the ends of the wires. conductors 7 and 7a so as to keep them in contact with each other. This connection plate with guide spark gap allows self-protection of the cable against dielectric breaks (by breakdown).

 Due to the staggering of the various individual connections, the connection device then constitutes a multi-axial connection system, whereas in the case of FIG. 1, it constitutes a coaxial connection system.

 FIG. 4A represents an alternative embodiment of the two external half-shells of each elementary connection system. In this variant, the contact surfaces of the two corresponding half-shells 13a do not extend radially, but are inclined so as to constitute, as it were, ramps 27 for centering which favor the range of the two half-shells 13a one against the other. For the rest, any other suitable profile of the contact surfaces of these two half-shells could be provided for this purpose.

 FIG. 7 shows another alternative embodiment of the half-shells 13 of each elementary connection system. In this variant, a semi-annular elastic blade 28 is provided inside each of the corresponding half-shells 13a. This blade, of curved section, is partially engaged inside the groove 17 of the corresponding half-shell 13b. The purpose of the elastic blades thus provided is to counteract the creep or packing effect of the external envelope 6 or 6a of the corresponding cable when the assembly is tightened.

 Furthermore, a socket 29 can be provided at the end of these half-shells which comprises the external shoulder 15. This socket 29 is intended to receive a grounding conductor 30.

 FIG. 8 shows yet another embodiment of the half-shells of each elementary connection system, which is designed to be able to be used in particular for the connection of relatively thick metal sheaths 5, 5a. The corresponding half-shells 13c have, on their internal wall, a projecting semi-annular rib 31 arranged transversely and which comprises an acute edge. Opposite, the corresponding internal bush 12c has a shallow groove 32 in place of the annular rib 16 provided in the embodiment according to FIG. 3. When the half-shells 13c are tightened, the edges 31 thus provided are brought to penetrate into the material of the outer insulating envelope 6 and pass through it to come into direct contact with the metal sheath 5 of the corresponding cable 1. This therefore makes it possible to obtain a direct conductive connection between the external half-shells 13c and this sheath metallic. In addition the penetration of the ribs 31 in the material of the outer casing 6 has the advantage of ensuring the locking in place of the end of the corresponding cable.

 To avoid completely cutting the outer sheath 6 and allowing a better attack in the material of this sheath at the time of tightening, the ends of the rib 31 of each half-shell 13c advantageously include a shelving or bevel 33. Besides, this rib does not extends only over an angle slightly less than 180 (see Figure 9) in order to avoid completely cutting the sheath 6.

 Figures 10 and 11 show an alternative embodiment in which the projecting rib provided inside the outer half-shells is constituted by a separate element 34 of semi-annular shape which also includes an internal algae edge. This element is partially housed inside a groove 35 formed in the internal wall of the corresponding half-shells 13d. However, a spring 36 is interposed to ensure elastic pressure of the penetration element 34 thus provided.

 It should be noted that in certain cables intended to be connected by means of the connection device according to the invention, there is provided a shielding sheath 5d having a series of undulations (see FIG. 12). In such a case, as in the case of relatively thick metal sheaths, it is advantageous to use the embodiment in which the external half-shells of each elementary connection system comprise a projecting rib 31 or a separate penetration element 34 inside the outer insulating casing 6 in order to ensure anchoring in this casing and direct contact with the metal sheath Sd (see FIG. 12).

 Figure 13 is a simplified partial sectional view showing the interlocking of two external sheaths 10d and 10e of a connection device according to the invention in which the conductive connection between these two sheaths is ensured by nesting of one or two cages link 37, forming multiple contacts, such as that shown in Figure 14. The purpose of using such cages is to achieve an optimum conductive connection between the projecting portions 21d and 21e of the sleeves of the two elementary connection systems.

 FIG. 15 represents a variant of the connection device according to the invention in which the corresponding external sheaths 10f and 10g are provided with an external system for connecting the ends of the metallic carrying cables 38 and 38a associated with the two conducting cables 1 and the connected by this device. To this end, a metal connection piece 39 is attached to the two sleeves 10f and long, an insulating seal 40 which can be interposed to produce a protective spark gap calibrated according to the desired level of protection, in the case of a mounting on metal posts. This system makes it possible to avoid the oxidation of such posts under the effect of telluric currents. The connection piece 39 comprises a longitudinal groove 41 intended to receive the ends of the two carrying cables 38 and 38a to be connected, a cover 42 then being reported on the whole. However, inside this cover, as well as inside the groove 41 of the part 40, there are provided several ribs 43 with algae edges intended to partially penetrate the ends of the cables 38 and 38a in order to ensure the joining of these with the present connection device and also providing a conductive connection between these two cables.

 Of course, the connection device according to the invention is not limited to the few exemplary embodiments described above for information only and which may be subject to various modifications. Thus for the permanent tightening of the two half-shells 13 (or 13a, 13b, 13c, 13d) of each elementary connection system, it is possible to provide any suitable means, other than the screws 45. Furthermore, for external protection of the assembly it is possible to provide overmolding of a plastic envelope in place of the sleeve 24 of heat-shrinkable material.

 But again many other variations are possible. FIG. 18 illustrates a variant in which the two elementary connection systems are connected by a single metal sheath 10f constituted by two half-sheaths 18f, one and the other ends of which are attached respectively around the external half-shells of the one and the other of these two elementary systems. The fixing of these half-sleeves 18f on the corresponding half-shells 13f is ensured by screws 19f engaged in longitudinal notches 20f provided in the ends of the half-sleeves 18f, which allows a certain freedom of position adjustment. single 10f thus formed plays exactly the same role as the two complementary sheaths 10 and îOa provided in the previous embodiments. In fact, it provides a conductive connection between the shielding sheaths of the two corresponding cables and it constitutes a shielding cage around the connections of the ends of the conductors of these two cables.

 FIG. 19 illustrates another variant in which the two metallic connection sleeves, carried by the two elementary connection systems, and which are able to be fitted one inside the other, each consist of two half-sleeves 18g making body with the 13g half-shells of these two elementary systems. As shown in FIG. 19, each of these half-sleeves 18g therefore consists of a skirt-shaped extension forming an integral part of the half-shell 13g of the corresponding elementary connection system. The connecting sleeves thus formed are able to be fitted into one another in the same way as the sleeves 10 and îOa of the previous embodiments, to play the same role as these.

 As already indicated, the device according to the invention is intended to be used for the connection of cables to one or more conductors each time these comprise a metallic sealing or shielding sheath. However, the present device can also be used for the connection of cables 2h and 21 comprising several concentric shielding sheaths, for example two sheaths 5 and 5h or 5 and 5i.

 In such a case (see FIG. 20), two pairs of elementary connection systems are provided, such as the systems 9 and 9a provided in the embodiment according to FIGS. 1 to 4. In this case, two concentric elementary systems 9h and 49h for the 2h cable, and two other concentric elementary systems 91 and 491 for the cable 21. The two internal systems 49h and 49i provide a connection with the first shielding sheath 5 of the two cables 2h and 2i. As for the two external systems 9h and 9i, they make a connection with the second shielding sheath 5h or 5i of these same two cables.

 However, the elementary systems of each pair are connected to each other respectively by two sleeves 10 and by two other sleeves 10h and 10i. The two sleeves of each pair are nested one inside the other.

However, they could be replaced by a single sheath, as in the case of FIG. 18. The two internal sheaths 10 finally ensure the connection of the internal sheaths 5 of shielding of the two cables 2h and 2i. As for the two external sheaths 10h and 101, they connect the two external shielding sheaths 5h and 5i of these two cables.

 Furthermore, due to the design of the device according to the invention, part of it can be used to secure a shielded cable 2j on a metal wall 50 that this cable must pass through. This fixing is then ensured with the constituent elements of a single elementary connection system 9 or 9a. The internal sleeve 12 of this system is engaged inside the shielding sheath 5 of the corresponding cable 2j and the two half-shells 13 are then added around. After interposing a support washer 51 in two parts, the assembly is engaged inside the passage hole 52 provided in the wall 50.

The external shoulder 15 of the half-shells 13 being fixed on the support washer 51 by means of screws 53, this washer is itself fixed on the wall 50 by means of other screws 54. A cap 55 d sealing can be added on the whole. Optionally the half shells 13 could be modified so that the support washer 51 is an integral part of these.

 The device thus constituted has the advantage of ensuring the connection of the sheath. metal shielding 5 with the metal wall 50 which can form a Faraday cage, which allows the flow of parasitic screen current outside the corresponding protected enclosure. Moreover, such an enclosure then plays in a way the same role as the shielding cage constituted by the metal sleeves provided in the embodiments previously described. However, in such a case, a large cable, thus fixed at its entry into such a metal cage, can then be connected to one or more protective sheaths of one or more cables emerging from this same cage.

Claims (14)

 1.- Connection device for conductive cables having a metallic sealing or shielding sheath against electromagnetic induction, this device comprising two elementary connection systems intended to be fixed respectively on one and the other sheaths to be connected and which are themselves connected to each other by a conductive link, while the cable conductors are connected by other suitable connection means, characterized in that it comprises  - on the one hand, for each metal sheath (5, 5a) to be connected, an elementary connection system (9, 9a) constituted by the combination of an internal metal sleeve (12, 12b) capable of being engaged under the end of this sheath around the end of the corresponding conductor (s) (3, 7), and two external metal half-shells (13, 13a, 13b, 13c, 13d) intended to be clamped around 1? end of this same metal sheath (5, 5a) and of its outer insulating envelope (6), by suitable means (45) of assembly, being placed in contact with a flange (14) carried by the internal metal sleeve (12, 12c) and which is arranged outside the end of the metal sheath (5, 5a) and its outer insulating envelope (6)  - on the other hand one or two metal sleeves (10, 10a, lOb, vioc, lord, 10e, 10f) for connection which can be attached to the half-shells (13, 13a, 13b, 13c, 13d) of the one and the other of these two connection systems and which are capable of constituting a shielding cage around the connections of the ends of the conductor (s) of the corresponding cables.  2.- Connection device according to claim 1, characterized in that the internal metal sleeve (12, 12b, 12c) of each elementary connection system (9, 9a) is secured to the corresponding external half-shells (13, 13a , 13b, 13c, 13d) by means of screws (46) or other connecting members passing through the flange (14) of this internal metal sleeve.  3.- Connection device according to claim 1 or 2, characterized in that the internal metal sleeve (12) of each elementary connection system (9, 9a) comprises a transverse annular rib (16) capable of causing a stretching of the corresponding material of the corresponding metal sheath (5, 5a) by imparting a corresponding deformation to it, the internal wall of the two external half-shells (13) having a groove (17) facing it.  4.- Connection device according to claim 1 or 2, characterized in that, on their internal wall, the two external metal half-shells (13b) of each elementary connection system comprise a semi-annular transverse rib (31) to sharp edge able to penetrate and pass through the insulating outer casing (6) of the corresponding metallic sheath (5) to come into contact with the latter.  5.- Connection device according to claim 4, characterized in that the semi-annular ribs, provided on the inner wall of the two half-shells (13d) of each elementary connection system, are constituted by independent elements (34) subjected to the pressure of thrust springs (36) and which are partially housed inside a transverse groove (35) provided in these two half-shells.  6.- Connection device according to one of the preceding claims, characterized in that the connection of the two elementary connection systems (9, 9a) is ensured by two metal sleeves (10, lova) attached respectively around the external half-shells (13, 13a) of one and the other of these two elementary systems and which are capable of being fitted one into the other.  7.- Connection device according to claim 6, characterized in that the connection sleeve of each elementary connection system consists of two half-sleeves (18) fixed one and the other on the two external half-shells (13) corresponding.  8.- Connection device according to claim 7, characterized in that in each connection system, the joint plane (AB) of the two connecting half-sleeves (18) of each elementary connection system is angularly offset with respect to the joint plane (CD) of the two corresponding half-shells (13).  9.- Connection device according to one of claims 6 to 8 characterized in that the external sleeves (10, lova, lOb, vioc) of connection are fixed on the half-shells (13) of the two elementary connection systems by through screws (19) engaged in longitudinal slots (20) provided in these sleeves, which allows a position adjustment in the longitudinal direction.  10.- Connection device according to claim 6, characterized in that the metal connection sleeves carried by the two elementary connection systems, and which are capable of being fitted one into the other, are constituted by half sleeves (18g) integral with the half-shells (13g) of these elementary connection systems.  11.- Connection device according to one of the preceding claims, characterized in that between the external sleeves (lord, 10th) for connection of the two elementary connection systems, two complementary cages (37) are provided for providing a multitude of connecting contacts between these sleeves.  12.- Connection device according to one of claims 1 to 5, characterized in that the connection of the two elementary connection systems is provided by a single metal sheath (10f), one and the other ends are reported respectively around the outer half-shells (13f) of one and the other of these two elementary systems and fixed thereon by means of screws (19f) or the like preferably engaged in notches or longitudinal slots (20f).  13.- Connection device intended to ensure the connection of cables comprising two or more concentric shielding sheaths, characterized in that it comprises several pairs of elementary connection systems according to one of the preceding claims intended to be connected respectively to the one and the other of the shielding sheaths of each cable (2h, 2i), the elementary connection systems of the same pair being connected by one or two metallic connection sleeves (10, 10h, lOi) according to the claims previous.  14.- Connection device according to one of the preceding claims, intended to be used in the case of a conductive cable associated with a carrying cable, and characterized in that the external metallic sheath (s) (10f, long) of this device carries receiving and fixing elements (39, 42) for the ends of the corresponding carrying cable (38, 38a), and there is interposed an insulating seal (40) providing a protective spark gap.