EP0717420A1 - Manufacturing process of a shielding jacket on an electrical conductor harness, and harness obtained by such a process - Google Patents

Abstract

The fabrication procedure involves forming the electromagnetic sheath that protects the cable bundle where the cable bundle branches. A ring (b2) is fitted round the outside of the cable bundle before the branch. The protective sheath of the cable is slit to allow emergence of a branch (B2) beyond the ring. The protective sheath (EG1) is closed over the continuing part of the cable bundle, and a second ring fitted over the first ring, overlapping the end of the sheath and clamping it in place. The rings are of an electrically conductive material, and are of a flexible material coated with adhesive.

Description

The present invention relates to bundles of electrical conductors, in particular those called harnesses, which are hardened, that is to say shielded against electromagnetic disturbances, and which are intended to electrically connect the various devices of a complex electrical installation , the proper functioning of which must be ensured, even in the event of electromagnetic interference. Such harnesses are, for example, used on board aircraft, ships, tanks, etc. The present invention relates to a method for producing such an armored harness or harness, as well as the beam obtained by the implementation of said method.

It is known that these harnesses consist of a bundle of conductors, stranded or not, distributed in several sub-bundles or branches, from branch nodes arranged along said bundle and connectors arranged at the free ends of said branches.

To be able to be shielded against electromagnetic disturbances, said harnesses are coated with braided metallic sheath elements completely covering said conductors. In known manner, such metal sheath elements can be produced beforehand in the form of braid portions, then threaded onto said harness branches and finally electrically connected to each other by sleeves, for example heat shrinkable, at said knots. branch line, to ensure mechanical and electrical continuity of said metal sheath. Alternatively, also known, each metal sheath element can be braided directly on each of said branches of the harness and include an extension on another branch serving to ensure the electrical continuity of sheath. For the latter purpose, it is also possible to provide overstressing at the branching nodes.

The first of the known methods mentioned above leads to the production of shielding sheaths whose electromagnetic performance is relatively low and whose mechanical resistance, in particular to vibration, is insufficient (which moreover further reduces the electromagnetic performance).

On the other hand, the second method (braiding directly on the branches of the bundle) allows excellent electromagnetic performance and mechanical resistance. However, it often happens that, at the beginning and / or at the end of braiding, the ends of the metal strands constituting the braided sheath element straighten orthogonally to the branch carrying said element, so that the insulator of the electrical conductors objects and / or objects coming into contact with said element are perforated and / or damaged by said straightened ends. In addition, this second method often requires, so that the braided sheath elements provide sufficient protection, that said branches each carry two such elements, which increases the mass and costs.

The object of the present invention is to remedy these drawbacks by avoiding the straightened ends of the weaving strands and by ensuring the best compromise between costs, mass and electromagnetic performance.

• à l'emplacement prévu pour une extrémité d'un élément de gaine sur une branche, on dispose une première bague enserrant ladite branche ;
• on procède ensuite au tressage dudit élément de gaine de telle sorte que ladite extrémité repose sur ladite première bague ; et
• on recouvre ladite extrémité dudit élément de gaine par une seconde bague, enserrant ladite première bague.

To this end, according to the invention, the method for producing a metallic sheath of electromagnetic shielding on a bundle of multi-branch electrical conductors, method according to which elements are braided directly on the branches of said bundle, from metallic strands of qaine which surround the said conductors of the branches and which are electrically connected to each other to form said metallic sheath, is remarkable in that:

• at the location provided for one end of a sheath element on a branch, there is a first ring enclosing said branch;
• then braiding said sheath element so that said end rests on said first ring; and
• covering said end of said sheath element with a second ring, enclosing said first ring.

Thus, said rings prevent the ends of the metallic braiding strands from straightening inward and / or outward and injuring objects in contact with them. In addition, they make it possible, as will emerge from the description below, to achieve excellent electromagnetic protection, with a single braiding layer on the branches of the bundle.

Advantageously, said rings are made of an electrically conductive material, they are flexible and adhesive.

Preferably, the adhesive of said rings is also electrically conductive.

By way of example, these rings can be portions of a thin metallic strip, for example made of copper.

Thanks to these features, said rings participate strongly in the cohesion of the bundle and its shielding sheath, as well as in the electrical and mechanical continuity between the various sheath elements.

In known manner, the bundles of electrical conductors generally comprise nodes each uniting three branches of said bundle. In this case, at each of said nodes, three sheath elements are formed, each of which passes from one of the three branches to one of the other two while being laterally crossed by the other of said two other branches, at least one end of said elements being trapped between said first and second rings, and the pair of branches carrying each of said three sheath elements is different from the pairs of branches carrying the other two sheath elements.

In the particular case where these three branches have different sections, it is advantageous to start by making a first sheath element carried by the two branches having respectively the smallest and the strongest section, then a second sheath element carried by the two branches respectively having the intermediate section and the smallest section and finally a third sheath element carried by the two branches having respectively the intermediate section and the largest section.

In addition, said first, second and third sheath elements may cover, respectively, all of said branch having the smallest section, all of said branch having the intermediate section and all of said branch having the largest section and, partially, near said node, said branch having the largest section, said branch having the smallest section and said branch having the intermediate section.

On the other hand, in particular when two of the three branches have at least approximately equal sections, it may be advantageous for one of said sheath elements to continuously and entirely cover said two branches.

In particular in this case, it is particularly advantageous for one of said sheath elements to start on a branch, in the vicinity of said node, and ends, on another branch, also in the vicinity of said node.

When, in a known manner, an electrical connector is mounted at the free end of a branch of the bundle carrying a metal sheath element, it is advantageous to produce a vacuum braiding tail at the end of said sheath element adjacent to said connector, to fold down said braiding tail on the end of said sheath element which externally surrounds the tip of said connector through which said branch penetrates inside thereof, and to fix by clamping said folded braiding tail and said end of said sheath element on said tip.

Thus, a solid fixing of this end of the sheath element is obtained on the connector, which makes it possible to handle the latter (connection and disconnection) without initiating de-stressing of said end.

In the particular case where the bundle of electrical conductors has the form of a harness having a main trunk gradually thinner and comprising nodes from which said branches are derived, the production of said sheath elements is preferably carried out from the branches the finest to the largest branches.

However, in order to take advantage of an already existing setting of the braiding loom producing said sheath elements and thus to reduce the total braiding time, when close branches, but not necessarily consecutive, have approximately equal sections, the braiding of the elements of corresponding sheaths are carried out consecutively.

Furthermore, the present invention also relates to a bundle of multi-branch electrical conductors coated with a metallic sheath of electromagnetic shielding, formed by sheath elements braided directly on the branches of said bundle, from metallic strands. According to the invention, at least one of the ends of said sheath elements is trapped between two superimposed rings, enclosing the corresponding branch of said bundle.

When electrical connectors are provided at the ends of said branches opposite to said node, said bundle is remarkable in that, on the side of a connector, the corresponding sheath element comprises a vacuum braiding tail, which is folded over the portion of sheath surrounding the tip of said connector through which the corresponding branch enters the connector and which is clamped against said tip.

The figures of the appended drawing will make it clear how the invention can be implemented. In these figures, identical references designate similar elements.

Figure 1 shows a portion of a bundle of electrical conductors, in the vicinity of a node connecting three branches.

Figure 2 shows, in cross section and on a larger scale than Figure 1, a bundle of electrical conductors, provided with a metal sheath of electromagnetic shielding.

FIGS. 3A to 3J schematically illustrate different stages of an example of implementation of the process for producing braided sheath elements at the node of FIG. 1, in accordance with the present invention.

FIGS. 4A to 4H illustrate an alternative embodiment of the braided sheath elements.

FIG. 5 illustrates the fixing of a sheath element in the vicinity of a connector.

FIG. 6 illustrates an exemplary implementation of the present invention for shielding a harness of conductors by the production of protective sheath elements, in accordance with the present invention.

Figure 7 shows another example of harness capable of being shielded in accordance with the invention.

In Figure 1, there is shown a portion of a bundle F of electrical conductors C, stranded or not, in the vicinity of a node N connecting three branches B1, B2 and B3 of said bundle F.

Usually, as shown in cross section in Figure 2, in order to harden said bundle F, each branch of the latter is surrounded by an element EG of braided metallic sheath G protecting the corresponding conductors C, against disturbances electromagnetic external. As has been mentioned above, preferably, each sheath element EG is produced by direct braiding on the corresponding branch of the bundle F, for example by means of a braiding loom.

As follows from the explanations below, in particular with regard to FIGS. 3A to 3J, the production of the sheath elements EG in accordance with the present invention is carried out branch after branch, with partial overlapping of another branch, in order to ensure a satisfactory covering of all N nodes.

With the aid of FIGS. 3A to 3J, an embodiment of the braided sheath elements EG on the bundle F is described, at the level of a node N. In the example of bundle F of FIG. 3A, it has been assumed that the beam portion F has branches B1, B2, B3 of unequal sections, the branch B1 having the smallest section and the branch B3 the largest.

As illustrated in FIG. 3B, one begins, in this example, to install a first ring b1, enclosing the branch of larger section B3 in the vicinity of the node N, at the location provided for the beginning end of a sheath element EG1 (see below). This first ring b1 can consist of a portion of electrically conductive metallic tape, for example of copper.

Preferably, this conductive tape is adhesive, with conductive glue or not, so as to be able to easily adhere to the branch B3 by perfectly matching the periphery of the latter. The tape must ensure that any straightened ends of the sheath element EG1 cannot injure the conductors C of the harness F.

Then (FIG. 3C), the bundle F is put in place in the braiding loom and there is then produced, starting approximately from the middle of the first ring b1 and in the direction of the node N, the sheath element EG1 which comprises a part P1 covering the branch B3 in the vicinity of the node N and which completely covers the branch B1. This sheath element EG1 is produced so that the branch B2 crosses it laterally, at its connection to the node N. The braiding parameters (number of braided strands, number of coils distributing said strands and no braiding) are adjusted for that said sheath element EG1 and its part P1 cover, without gaps and without overlaps, respectively the entire branch B1 and partially the branch B3. Since it is assumed that the branch B1 has a smaller section than the branch B3, it is seen that it is necessary that the braiding pitch on the branch B3 (part P1) is smaller than on the branch B1.

As shown in Figure 3D, we then block the beginning of the sheath element EG1, on the first ring b1, by a second ring b2 which encloses the corresponding end of said sheath element EG1 and which is superimposed on the first ring b1. The second ring b2 can be produced in a similar way to the first ring b1 and it ensures that the ends of the metal strands, forming said sheath element EG1, cannot straighten outwards. Thus, said ends are trapped between said first and second rings.

Then (FIG. 3E), a third ring b3 (similar to the previous ones) is placed, enclosing the sheath element EG1 on the branch B1 in the vicinity of the node N, at the location provided for the beginning end of a EG2 sheath (see below). The ring b3 must ensure that the braiding strands of this sheath element EG2 cannot damage the sheath element EG1 and / or the underlying conductors C.

Similar to what has been described above with respect to the sheath element EG1, the braiding of the bundle element F (see FIG. 3F) is continued by making, starting approximately from the middle of the third ring b3 and in the direction of node N, the sheath element EG2, which includes a part P2 covering the sheath element EG1 (that is to say the branch B1) in the vicinity of said node N and which completely covers the branch B2. The branch B3, partially covered with the braiding part P1, laterally crosses the sheath element EG2, at its connection to the node N. Of course, because of the section reports given in hypothesis, the braiding pitch of the element EG2 is larger on the branch B1 than on the branch B2.

As shown in FIG. 3G, the starting end of the sheath element EG2 is blocked on the third ring b3, by a fourth ring b4, which encloses the corresponding end of said sheath element EG2 and which is superimposed on the third ring b3. The fourth ring b4 can be produced in a similar way to the three preceding rings b1, b2 and b3 and it ensures that the ends of the metal strands, forming the sheath element EG2, cannot be straightened, these ends being trapped between said third and fourth rings b3 and b4.

Then, as shown in FIG. 3H, a fifth ring b5 (similar to the previous ones) is placed, enclosing the sheath element EG2 on the branch B2 in the vicinity of the node N, at the location provided for the start end of an EG3 sheath element (see below). The ring b5 must ensure that the braiding strands of this sheath element EG3 cannot damage the sheath element EG2 and / or the underlying conductors C.

Similar to what has been described above, there is then produced (see FIG. 3I), starting approximately from the middle of the fifth ring b5 and towards the node N, the sheath element EG3, which has a part P3 covering the sheath element EG2 (branch B2) in the vicinity of said node and which completely covers branch B3. The branch B1, covered with the sheath element EG1 and the braiding part P2, laterally crosses the sheath element EG3, at its connection to the node N. The braiding pitch on the branch B2 is greater than on branch B3. The EG3 sheath element covers the first and second rings b1 and b2 of the EG1 sheath element and locks them in position.

Then, as shown in FIG. 3J, the starting end of the sheath element EG3 is locked on the fifth ring b5, by a sixth ring b6, which encloses the corresponding end of said sheath element EG3 and which is superimposed to the fifth ring b5. The sixth ring b6 can be produced in a similar manner to the previous five rings b1 to b5 and it ensures that the ends of the metal strands, forming the sheath element EG3, cannot be straightened, these ends being trapped between said fifth and sixth rings b5 and b6.

The embodiment of the invention, illustrated by FIGS. 3A to 3J, is only one example of braiding among others, which takes into account the differences in section of the branches B1, B2 and B3. However, it is immediately obvious that it is possible, for example for reasons of convenience or topology, to reverse the directions of braiding, that is to say to start braiding the sheath elements EG1, EG2 and EG3, respectively. at the ends of the branches B1, B2 and B3, opposite the node N, and finish it, respectively on the rings b1, b3 and b5.

The embodiment described with reference to FIGS. 3A to 3J and that in the reverse braiding direction, mentioned above, are particularly advantageous, since they ensure good seating of the sheath element EG1 on the branches B1 and B3, then of the EG2 sheath element on the branch B2 and on the EG1 sheath element. The EG2 sheath element is thus prevented from slipping when handling the harness during braiding. Likewise, the sheath element EG3 strongly adheres to the beam F, thanks to its retention by the sheath elements EG2 and EG1 (part P1).

Thus, even if the angle between the branches B1 and B2 is very acute (closed), there is no risk of slipping of the sheath elements EG1, EG2 and EG3.

From the above, it will be easily understood that the use of rings b1 to b6 made of adhesive conductive tape with conductive glue, is advantageous, since such rings improve electrical continuity and participate in the cohesion of the sheath elements EG1, EG2, EG3 between them.

• au voisinage du noeud N, on dispose (voir la figure 4B), une bague b7, sur la branche B1, et une bague b8, sur la branche B3. Ces bagues b7 et b8 sont comparables à la bague b1 de la figure 3B ;
• puis, on tresse un élément de gaine EG4, recouvrant partiellement la branche B1 et la branche B3, ledit élément de gaine EG4 commençant à cheval sur la bague b7 et finissant à cheval sur la bague b8 (voir la figure 4C) ;
• on recouvre les extrémités de l'élément de gaine EG4 par des bagues b9 et b10, respectivement superposées aux bagues b7 et b8 (voir la figure 4D) ;
• on tresse un élément de gaine EG5, recouvrant en continu et totalement les branches B1 et B2 (voir la figure 4E) ;
• on dispose sur l'élément de gaine EG5, sur la branche B2 et au voisinage du noeud N, une bague b11, comparable à la bague b3 de la figure 3E (voir la figure 4F) ;
• on tresse un élément de gaine EG6, commençant à cheval sur ladite bague b11 et recouvrant partiellement la branche B2 et totalement la branche B3 (voir la figure 4G) ; et
• on recouvre l'extrémité de commencement de l'élément de gaine EG6 par une bague b12, superposée à la bague b11.

In FIGS. 4A to 4H, an alternative embodiment of the sheath elements forming the braided sheath G has been shown, said variant being very particularly suitable for being implemented when the branches B1 and B2 are of identical sections (see FIG. 4A ). According to this alternative embodiment:

• in the vicinity of the node N, there is (see FIG. 4B), a ring b7, on the branch B1, and a ring b8, on the branch B3. These rings b7 and b8 are comparable to the ring b1 in FIG. 3B;
• then, a sheath element EG4 is braided, partially covering the branch B1 and the branch B3, said sheath element EG4 starting astride the ring b7 and ending astride the ring b8 (see FIG. 4C);
• the ends of the sheath element EG4 are covered with rings b9 and b10, respectively superimposed on the rings b7 and b8 (see FIG. 4D);
• a sheath element EG5 is braided, continuously and completely covering the branches B1 and B2 (see FIG. 4E);
• there is on the sheath element EG5, on the branch B2 and in the vicinity of the node N, a ring b11, comparable to the ring b3 in FIG. 3E (see FIG. 4F);
• a sheath element EG6 is braided, starting astride said ring b11 and partially covering the branch B2 and completely the branch B3 (see FIG. 4G); and
• the beginning end of the sheath element EG6 is covered with a ring b12, superimposed on the ring b11.

In Figure 5, there is shown the end L of a braided metallic sheath element EG (which can be any one of the elements EG1, EG2, EG3, EG5 or EG6), opposite the node N and it has been assumed that this end L was connected by external fitting on the end piece EB of a connector CN. The branch of the harness F, which carries the sheath element EG, penetrates inside the connector CN, through the said end piece EB. In this case, it is advantageous to provide, at the external part of the end L, a vacuum braiding tail Q, which is folded over the part of the end L fitted onto the end piece EB and which is clamped there against this by a hose clamp Co.

Of course, the braiding of the sheath element can start with the tail Q and end by imprisonment between said first and second rings (b1, b2; b3, b4; b5, b6; b11, b12), or vice versa start on said rings and terminate with said braiding tail Q. Such a braiding tail is easy to perform when empty, when the bundle F is not in place in the loom to be braided.

The harness H, shown in FIG. 6, represents a particular case of bundle of conductors F, in which the conductors C form a main trunk, from nodes from which branches are derived. In the example of FIG. 6, the harness H comprises nodes Ni five in number (i = 1, 2, 3, 4 or 5) and the branches leaving or arriving at a node Ni bear the references B1i, B2i and B3i, by analogy to branches B1, B2 and B3 above.

In FIG. 6, arrows have been drawn symbolizing the direction of braiding of the various sheath elements: the origin of an arrow marks the start of braiding and the end of an arrow indicates the braided branch and the end point of braiding. The thickness of the lines of the branches of the harness symbolizes the sections of the different branches.

The metal sheath is formed on the harness H of FIG. 6 by progressing from the branches of smaller sections towards the branches of larger sections, by implementing the features illustrated by FIGS. 3A to 3J or 4A to 4H, According to the case.

Thus, we begin by making the sheath element EG11 which begins on the branch B31 (which corresponds to the branch B22 of the node N2) and ends on the terminal branch B11 of smaller section. Then, the sheath element EG21 is produced, which begins on the branch B11 and ends on the branch B21, of section greater than the branch B11 but less than the branch B31.

If the branch B12 has the same section as the branch B21 (that is to say that the braiding parameters are the same for said branches B12 and B21), the sheath element EG12 which covers the branch B12 is then produced. and begins on branch B32 (which corresponds to branch B23 of node 3). This optimizes the braiding time and the use of the braiding loom, subsequently producing the sheath elements having the same weaving parameters.

The sheath element EG31 is then produced by making it start on the branch B21, cover the entire branch B31 (B22) and stop on the branch B12.

We then proceed to the braiding of the element EG13, which covers the branch B13 with beginning on B33 (B24), because the branches B31 and B13 are supposed to be similar. Then, to that of the element EG32 starting from the branch B13, covering the branch B32 (B23) and stopping on the branch B31 (B22).

The two branches B15 and B25 are assumed to have the same section. We can then make a short sheath element EG5 starting from B14 (B35) near the node N5 and stopping on the branch B15, near N5. The branches of identical section B15 and B25 are then covered by a single sheath element EG15 (EG25), which begins at the end of the branch B15 and stops at the end of the branch B25.

• on réalise un court élément de gaine EG4, qui part de la branche B33 (B24) à proximité du noeud N4 et qui s'arrête sur la branche B14 (B35), toujours à proximité du noeud N4 ;
• on réalise l'élément de gaine EG14, qui commence sur la branche B25, recouvre la branche B14 (B35) et se termine sur la branche B34, à proximité du noeud N4 ;
• enfin, on réalise l'élément de gaine continu EG33-EG34 qui part de la branche B32 (B23) et recouvre les branches B33 (B24) et B34, en passant par le noeud N4.

The branches B33 (B24) and B34 have neighboring sections, which makes it possible to use, on the braiding loom, identical numbers of strands and coils, only the braiding pitch being different. We can then follow the following procedure:

• a short sheath element EG4 is produced, which leaves from the branch B33 (B24) near the node N4 and which stops on the branch B14 (B35), always near the node N4;
• the sheath element EG14 is produced, which begins on the branch B25, covers the branch B14 (B35) and ends on the branch B34, near the node N4;
• finally, the EG33-EG34 continuous sheath element is produced which starts from the branch B32 (B23) and covers the branches B33 (B24) and B34, passing through the node N4.

FIG. 7 represents a harness H ′ comprising several branches connecting different equipment (not shown) and having variable sections, but having no main axis serving the different directions.

From what has just been described, it will be understood that the harness H 'of FIG. 7 can be coated with a braided protective sheath, just like the harness H of FIG. 6.

It can thus be seen that, thanks to the present invention, shielding sheaths for harnesses are easily produced, while benefiting from an excellent compromise between cost, mass and electromagnetic performance. In fact, except at the branching nodes, these sheaths have only one layer of braiding.

Claims (14)

Method for producing a metallic sheath of electromagnetic shielding (G) on a bundle (F) of electrical conductors (C) multibranch, method according to which braiding elements are directly braided on the branches of said bundle, from metallic strands sheath (EG) which surrounds said branch conductors and which are electrically connected to each other to form said metallic sheath,
characterized in that: - At the location provided for one end of a sheath element on a branch, there is a first ring (b1, b3, b5) enclosing said branch; - Then braiding said sheath element (EG1, EG2, EG3) so that said end rests on said first ring; and - Said end of said sheath element is covered by a second ring (b2, b4, b6), enclosing said first ring. Method according to claim 1,
characterized in that said rings are made of an electrically conductive material. Method according to one of claims 1 or 2,
characterized in that said rings are flexible and adhesive. Method according to claim 3,
characterized in that the glue of said rings is electrically conductive. Method according to one of claims 1 to 4, applied to a bundle of electrical conductors comprising nodes each joining three branches of said bundle,
characterized in that, at each of said nodes (N), three sheath elements (EG1, EG2, EG3) are formed, each of which passes from one of the three branches to one of the other two by being laterally crossed by the other of said two other branches, at least one end of said elements being trapped between said first and second rings, and in that the pair of branches carrying each of said three sheath elements is different from the pairs of branches carrying both other sheath elements. Method according to claim 5,
characterized in that, said three branches having different sections, one begins by producing a first sheath element (EG1) carried by the two branches (B1, B3) having respectively the smallest and the largest section, then a second element sheath (EG2) carried by the two branches (B2, B1) having respectively the intermediate section and the smallest section and finally a third sheath element (EG3) carried by the two branches (B2, B3) having respectively the intermediate section and the strongest section. Method according to claim 6,
characterized in that said first, second and third sheath elements (EG1, EG2, EG3) overlap, respectively, the whole of said branch (B1) having the smallest section, the whole of said branch (B2) having the intermediate section and the whole of said branch (B3) having the largest section and, partially, near said node, said branch (B3) having the highest section, said branch (B1) having the smallest section and said branch (B2) having the intermediate section. Method according to claim 5,
characterized in that, two of said three branches (B1-B2) having at least approximately equal sections, one of said sheath elements (EG5) continuously covers all of said two branches. Method according to claim 8,
characterized in that one of said sheath elements (EG4) begins on a branch, in the vicinity of said node (N), and ends, on another branch, also in the vicinity of said node. Process according to any one of Claims 1 to 9,
characterized in that, an electrical connector (CN) being mounted at the free end of one of said branches carrying such a metal sheath element, a vacuum braiding tail is produced at the end of said sheath element adjacent to said connector , in that said braiding tail is folded over the end of said sheath element which externally surrounds the end piece of said connector through which said branch penetrates inside said connector and in that said tail is fixed by clamping braided folded and said end of said sheath member on said tip. Method according to any one of Claims 1 to 10, applied to a bundle of conductors (H) having a progressively thinner main trunk and comprising nodes (Ni) from which said branches are derived,
characterized in that the production of said sheath elements is carried out from the thinnest branches (B11) to the largest branches (B34). Method according to claim 11,
characterized in that, when branches (B12, B21 - B33, B34) close, but not necessarily consecutive, have approximately equal sections, the braiding of the corresponding sheath elements is carried out consecutively. Bundle of multi-branch electrical conductors (F) coated with a metallic sheath of electromagnetic shielding (G), formed by sheath elements (EG) braided directly on the branches of said bundle, from metallic strands,
characterized in that at least one of the ends of said sheath elements is trapped between two superimposed rings (b1, b2 - b3, b4 - b5, b6), enclosing the corresponding branch of said bundle. Beam according to claim 13, provided with electrical connectors at the ends of said branches opposite to said node,
characterized in that, on the side of a connector, the corresponding sheath element comprises a vacuum braiding tail, which is folded over the sheath portion surrounding the end piece of said connector by which the corresponding branch enters the connector and which is clamped against said tip.

Images