FR2741136A1 - BYPASS SUPPORT, IN PARTICULAR FOR WIRE ROPE PATH - Google Patents

Abstract

This is a branch support of the kind comprising an opening (20A), which, of generally circular outline, is suitable for installing a sheath (19). According to the invention, this aperture (20A) is intersected by at least one other aperture (20B) of radius (RB) different from its own (RA). Application, in particular, to the equipment of a wire cable tray.

Description

"Bypass support, especially for wire cable tray" La

  present invention relates generally to the branch supports of the type used for guiding and protecting one or more cables

  locally extracted from a bundle of cables.

  It relates more particularly, but not necessarily exclusively, to the case where, the bundle of cables being carried by a cable tray made of wires, such a bypass support is intended to be attached to this cable tray, by being in overall practice backed by one of the

side wings of it.

  Depending on local usage, various provisions are adopted. According to a first of these provisions, the bypass support is essentially intended to allow the installation, transversely with respect to the cable tray, of a sheath, which is intended to ensure the

  guiding and protecting the derivative cable (s).

  It therefore essentially comprises a simple aperture, which, having a generally circular outline, to the diameter of the sheath, is specific to the installation of this sheath, the fixing of the latter being done in practice using with a simple fitting

assembly type.

  As a result, it is necessary to date to have as many branch supports of different types as there are possible diameters for the sheath, which does not increase the costs of the assembly, both for them

  manufacturers only for installers.

  In addition, to date, the fixing of branch supports of this type on a cable tray made of wires is usually carried out using bolts or screw-nut assemblies, which requires that these cable trays be adapted to such a method of attachment and requires the installer to have the necessary bolts or screw-nut assemblies and a clamping part. According to a second arrangement corresponding to another local use, the bypass support is essentially intended to allow the fixing, to the cable tray, of a box, which is intended to ensure the establishment of the necessary sheath (s) guiding and protecting the or

derived cables.

  In this case, therefore, it essentially only has a bore suitable for the passage of the necessary fixing member.

to the fixing of such a box.

  This fixing member, which must allow the passage of the derivative cable or cables, is in practice a fitting

  of assembly of the type of the preceding one, but of separate gauge.

  Again, this results in an expensive expansion of the range of different types of bypass supports that are necessary to be able to satisfy

  either of these two provisions.

  The present invention generally has for

  subject to a reduction in this range.

  More specifically, it relates to a bypass support of the kind comprising an aperture, which, of generally circular outline, is specific to the installation of a sheath, this bypass support being generally characterized in that that, according to a first aspect, this opening is

  intersected by at least one other aperture of radius different from his.

  This bypass support is thus advantageously able to allow the mounting of a sheath having one or

  the other of two different diameters.

  The range of different branch supports which it is necessary to have in order to satisfy sheaths of different diameters is thus advantageously reduced accordingly. In addition, with equal dimensions, the quantity of material whose bypass support according to the invention is hollowed out for the formation of its openings is advantageously minimized,

  for the benefit of its mechanical resistance.

  Preferably, but not necessarily necessarily, and in a manner known per se, the bypass support according to the invention is made of sheet metal, and, being in the general form of a square, it comprises two wings, one generally horizontal, for its application on the bottom of the cable tray, the other generally vertical, for its application against the side wing concerned thereof. Preferably, also, at least one of its wings comprises at least one foldable tab, for its attachment to the

path of cables.

  Thus, any bolting or any screwing is

advantageously avoided.

  According to a second aspect, the bypass support according to the invention is further characterized in that it is adapted to receive, on request, an auxiliary support, which, for the installation of a box, has a bore specific to the passage of the fixing member necessary for fixing

this box.

  Thus, according to local customs, it can be proceeded indifferently to the installation of a sheath or to that of a

box.

  It is sufficient, if necessary, to add to the bypass support according to the invention the auxiliary support which

is associated.

  But the latter advantageously benefits from the bypass support for its attachment to the cable tray, which in turn

  simplifies manufacturing and therefore minimizes the cost.

  Preferably, between the bypass support according to the invention and the auxiliary support which is associated with it, there are complementary nesting means which make it possible to attach this support by simple snap-fastening.

  auxiliary on this bypass support.

  As before, any bolting or any screwing

is thus advantageously avoided.

  Preferably, but not necessarily necessarily, the auxiliary support is also made of sheet metal, and it comprises, on the one hand, a plate, which comprises the necessary drilling, and, on the other hand, along two opposite edges of this platinum, two edges at the favor of which

  the corresponding nesting means are formed.

  In addition to the fixing function which they thus assume, these flanges jointly assume, by forming a spacer, a separation function, freeing, between the plate and the bypass support, the space necessary for the intervention of the fixing ensuring the fixing of the box to this plate. However, whatever its own constitution, the auxiliary support thus associated according to the invention with a bypass support advantageously makes it possible to very simply extend the field of application thereof, thereby reducing the range of branch supports of different types which are otherwise necessary, and

  thus promoting economic standardization of the whole.

  The characteristics and advantages of the invention

  will emerge from the description which follows,

  by way of example, with reference to the accompanying diagrammatic drawings in which: FIG. 1 is a partial perspective view of a cable tray made of wires and a bundle of electric cables housed therein; Figure 2 is, on a different scale, and with local cutaway, a partial perspective view of this cable tray, with, reported locally thereon, a bypass support according to the invention; Figure 3 is, on a larger scale, a perspective view of this bypass support, with, in an exploded manner, the sheath to be fixed on it; Figure 4 is an elevational front view of the bypass support according to the invention, according to arrow IV of Figure 3; Figure 5 is a side view, along arrow V of Figure 4; Figure 6 is a top view, along arrow VI of Figure 4; Figures 7, 8, 9 and 10 are, on a larger scale, partial views in cross section, each on the lines VII-VII, VIII-VIII, IX-IX and X-X of Figure 4, respectively; FIG. 11 is a partial front elevation view which, taking up, on a larger scale, the detail of FIG. 4 marked by an insert XI in this FIG. 4, illustrates the installation of a sheath on the bypass support according to the 'invention; Figure 12 is a partial front elevational view which, similar to that of Figure 11, relates to a sheath of different diameter; Figures 13 and 14 are partial front elevational views which, also similar to that of Figure 11, each relate respectively to two alternative embodiments; Figure 15 is a perspective view which, similar to that of Figure 3, illustrates the possible splitting of the bypass support according to the invention; Figure 16 is a perspective view which, similar to that of Figure 2, illustrates the addition of an auxiliary support to the bypass support according to the invention; Figure 17 is an exploded perspective view of the assembly; Figure 18 is an elevational front view of the auxiliary support, according to arrow XVIII of Figure 17; Figure 19 is a side view, along arrow XIX of Figure 18; Figure 20 is, on a larger scale, a partial view in cross section along the line XX-XX of Figure 18; FIG. 21 is a side view illustrating the positioning of this auxiliary support on the bypass support

according to the invention.

  These figures illustrate, by way of example, the application of the invention to equipping a railway

10 wire cables.

  In a manner known per se, this cable tray 10 is formed of a trellis of wires comprising, on the one hand, longitudinal wires 11, commonly called warp wires, which run longitudinally, for example in a rectilinear manner, or so almost straight, over its entire length, and, on the other hand, established transversely from place to place along these longitudinal wires 11, being suitably subject thereto, in practice by welding, transverse wires 12, commonly known as weft threads, which are generally U-shaped. In practice, the longitudinal threads 11 extend to

  the outside of the transverse wires 12.

  In practice, too, both the longitudinal wires 11 and the transverse wires 12 are round wires, of section

  transverse circular, and these are metallic wires.

  Overall, the cable tray 10 thus comprises, in the manner of a chute, a bottom 13, which is for example substantially planar, as shown, and, substantially square with this bottom 13, two lateral wings 14, which can

  also be substantially planar, as shown.

  This cable tray 10, the bottom 13 of which is shown here horizontal, is used to provide support, housing and protection for a bundle 15 of electrical cables 16 of which at least one must be locally derived laterally from this bundle 15, by virtue of the opening of one of the meshes of one of the lateral wings 14,

as shown in Figure 1.

  In a manner also known per se, and according to arrangements described in more detail later, it is attached, externally, to do this, on the cable tray 10, a bypass support 18, for implantation, at the corresponding location , a sheath 19 suitable for guiding,

  housing and protection of the 16-wire electrical cable.

  In the embodiment shown, this sheath 19 is a flexible sheath, and it is for example a corrugated sheath. Let DA be the outside diameter of the section

transverse of this sheath 19.

  In a manner known per se, the bypass support 18 comprises an aperture 20A, which, of generally circular outline, is specific to the installation of the sheath 19, its radius RA being

planned accordingly.

  In practice, the installation of the sheath 19 is done using an assembly fitting 21, comprising, in a manner known per se, two parts 21 ', 21 ", which, in screwing relationship, one relative to each other, are suitable for enclosing between them the end of the sheath 19, by intervening, one, on a first side of the bypass support 18, the other, of

the other side of it.

  According to the invention, the aperture 20A is intersected by at

  minus another aperture 20B of radius RB different from its own RA.

  For example, and as shown, this radius RB is

less than the radius RA.

  In the embodiment shown, the bypass support 18 is made of sheet metal, suitably cut and folded, and it is in the general form of a square. It therefore has two wings, namely, a wing 22, which, generally parallel to the bottom 13 of the cable tray 10, is therefore here generally horizontal, and by which it is intended to bear on the bottom 13 of the cable tray 10, on the internal face of this bottom 13, and a wing 24, which is generally vertical, and by which it is intended to bear on the lateral wing 14 concerned of the cable tray 10, on the face

external of this lateral wing 14.

  These two wings 22, 24 each have a plan in outline

  generally quadrangular, and in practice rectangular.

  At least one of them, and, in practice, each of them, comprises at least one foldable tab 25, for the

  fixing the assembly to the cable tray 10.

  In the embodiment shown, the horizontal wing 22 comprises, at a distance from each other, two foldable legs 25, which, generally parallel to one another, extend one and the other towards the wing

vertical 24.

  Jointly, the vertical wing 24 comprises, in the embodiment shown, four foldable legs 25, which, established along its lateral edges, are stepped in height, two at a row, and which, generally parallel to one another , all extend in opposite directions

to the horizontal wing 22.

  In the embodiment shown, the foldable legs 25 which thus comprise the two wings 22, 24 of the bypass support 18 are formed with the aid of punctures 26

of these.

  In the embodiment shown, the openings

  A, 20B affect the vertical wing 24.

  For at least one of the openings 20A, 20B, and, in practice, for each of these, the arc of a circle 27A, 27B which defines the outline thereof extends, even in cumulative value, over

more than 180.

  In other words, FIG. 11, the angle at the center AA, AB subtended by such an arc 27A, 27B is greater than 1800. In practice, this angle at the center AA, AB is understood

  between 180 and 260, for example being around 240.

  In any event, it is ensured that the points along which the openings 20A, 20B overlap each other are at a distance from each other less than the diameter of the sheath 19 of the smallest radius , measured at the bottom of the net, so that this sheath 19 cannot escape

  laterally with the corresponding aperture 20A, 20B.

  More generally, it is made so that a sheath 19 cannot escape laterally from the aperture

  A, 20B in which it was engaged.

  In the embodiment shown, the bypass support 18 according to the invention comprises at least two sets J of openings 20A, 20B, and at least one of these two sets J

  belongs to a breakable portion 29.

  In practice, the two sets J of openings 20A, 20B are staggered in height, with, between them, a line of least resistance 30 delimiting, in the vertical wing 24, two stages, namely, a lower stage 31, which is adjacent to the horizontal wing 22, and an upper stage, which forms the

breakable portion 29.

  The line of least resistance 30 is generally parallel to the edge 32 formed between them by the wings 22, 24, and it extends substantially at mid-height of the vertical wing 24. As is better visible at the Figure 8, this line of least resistance 30 is, for example, materialized by a groove 33, which cuts, at mid-thickness, the wing

  vertical 24, on the external face thereof.

  In the embodiment shown, the bypass support 18 according to the invention comprises, at a distance from each other, at least two sets J of openings 20A, 20B each of

its floors 31, 29.

  For example, and as shown, only two sets J of openings 20A, 20B are thus provided at each of these stages 31, 29. All these sets J of openings 20A, 20B are identical

  between them, and they generally have the same orientation.

  In practice, for each of them, the centers of the arcs

  27A, 27B are on a parallel to the edge 32.

  In the embodiment shown, the horizontal wing 22 forms a groove 34 at its connection to the vertical wing 24, to allow the intervention of the part 21 "of an assembly fitting 21, when the establishment of the

  sheath 19 is made on the lower stage 31 of the vertical wing 24.

  This groove 34 extends between, on the one hand, the foldable legs 25 of the horizontal wing 22, and, on the other hand, the vertical wing 24, and the latter directly forms one of the flanks. In the embodiment shown, the vertical wing 24 has, projecting, at an angle, on its internal face, a tongue 35, for its snap-fastening on a wire.

  longitudinal 11 of the cable tray 10.

  In practice, this tongue 35 affects the lower stage 31 of the vertical wing 24, in the median zone thereof, and it moves away from the horizontal wing 22 as it moves away of this vertical wing 24. In practice, also, this tongue 35 is formed

in favor of a flat 36.

  In the embodiment shown, the vertical wing 24 has, in addition to the openings 20A, 20B, various recesses 38, 39, such as at least one hole 38 and / or at least one buttonhole 39, for various uses, and , for example, for

  allow any auxiliary fixation.

  In practice, in the embodiment shown, only one hole 38 is provided, in the median zone of the vertical wing 24, and, jointly, there are four buttonholes 39, which radiate around the hole 38, and two of which, aligned one

  with the other, extend parallel to the edge 32.

  The line of least resistance 30 passes through at least

one of these recesses 38, 39.

  In practice, in the embodiment shown, it passes through the hole 38 and through the two buttonholes 39

  aligned parallel to the edge 32.

  It also passes through at least one of the punctures 26 to the

  in favor of which foldable legs are formed 25.

  In practice, two of these foldable legs 25 affecting the lower stage 31 of the vertical wing 24, the line of least resistance 30 transversely cuts across the two punctures

26 correspondents.

  For the implementation of the bypass support 18 according to the invention, it can for example be carried out as follows. Initially, this bypass support 18 is simply put in place on the cable tray 10, with its vertical wing 24 snapping onto one of the longitudinal wires 11 of the side wing 14 concerned in this cable tray 10 , thanks to the tongue 35 of this wing

vertical 24.

  Conjugated with the support of the horizontal wing 22 on the bottom 13 of the cable tray 10, this snap-fastening is sufficient for a temporary maintenance of the bypass support 18 on this route

  cables 10, which facilitates the following operations.

  Secondly, at least some of the foldable tabs 25 are hooked onto the longitudinal wires 11 of the cable tray 10, by folding these

  foldable tabs 25 around these longitudinal wires 11.

  Finally, finally, the

installation of the sheath 19.

  Depending on the outside diameter DA or DB of the cross section of the sheath 19, the positioning thereof is done with the aid of an opening 20A, as shown diagrammatically in broken lines in FIG. 11, or with the favor 20B, such

  shown schematically in broken lines in Figure 12.

  Thus, each set J of openings 20A, 20B makes it possible to implement a sheath 19 having one or the other of at least

two different diameters DA, DB.

  If the sheath 19 is placed in one or other of the openings 20A, 20B of the lower stage 31 of the vertical wing 24, the breakable portion 29 forming the upper stage of the latter can be eliminated, as shown schematically at

Figure 15.

  This can in particular be the case when the lateral wings 14 of the cable tray 10 have only one height

relatively small.

  In the above, only two openings 20A, 20B are provided for each of the games J.

  Alternatively, more than two openings 20A, 20B, 20C etc ...

  can be expected, by overlapping both in pairs.

  For example, Figures 13 and 14, three openings 20A, 20B,

C can thus be provided.

  In the embodiment shown in the figure

  13, these three openings 20A, 20B, 20C are aligned.

  In the embodiment shown in the figure

14, they are arranged in lobes.

  In all cases, the aperture 20B for example has a radius RB smaller than that RA of the aperture 20A, and the aperture 20C has for

  example a radius RC smaller than that RB of the aperture 20B.

  As will be noted, the arc defining a hole can be split. This is the case, in FIG. 13, for the aperture 20A, which is a median aperture for the assembly, and which is therefore defined by an arc of a circle divided into two portions. This is in particular the reason why it is the cumulative value of the angle at the center of the openings which is at

take into consideration.

  But, as previously indicated, it is made so that a sheath 19 cannot escape laterally from the aperture

in which she was engaged.

  In the embodiment shown, the bypass support 18 according to the invention is, moreover, according to another aspect, adapted to receive on request an auxiliary support 40, which, for the installation of a box 41, has a bore 42 suitable for the passage of a member of

  fixing 43 necessary for fixing this box 41.

  In the embodiment shown, there is provided, between the bypass support 18 and the auxiliary support 40, complementary fitting means making it possible to attach this support by simple snap-fastening

  auxiliary 40 on this bypass support 18.

  In practice, these complementary fitting means comprise, on the bypass support 18, at least one buttonhole 44, and, at a distance therefrom, a hook 45

directed to this buttonhole 44.

  At the same time, they comprise, on the auxiliary support 40, at least one tab 47, for cooperation with a buttonhole 44 of the branch support 18, and, at a distance from this tab 47, for cooperation with the hook 45 of the branch support 18, a tongue 48 directed in the opposite direction to the

tab 47.

  In the embodiment shown, the bypass support 18 comprises, at a distance from each other, two buttonholes 44, which affect its vertical wing 24, and which, aligned with each other, extend substantially parallel to the edge 32 that this vertical wing 24 forms with the horizontal wing 22, and the auxiliary support 40

  has, in correspondence, two legs 47.

  Jointly, in this embodiment shown, the hook 45 also affects the vertical wing 24 of the bypass support 18, and, in practice, it is formed by a folding of the free edge of this vertical wing 24 which, in the form of a butt , protrudes from the external face of this vertical wing 24, while the buttonholes 44 extend to the

vicinity of the horizontal wing 22.

  In the embodiment shown, the auxiliary support 40 is made of sheet metal, and it comprises, on the one hand, a plate 50, which has, in its central region, the bore 42, and, on the other hand, along two opposite edges of this plate 50, in this case its lower and upper edges, two flanges 51, with the aid of which the interlocking means 47, 48 are formed capable of making it possible to attach

  the assembly on the bypass support 18.

  More specifically, the tabs 47 that these interlocking means comprise are formed by angled returns from one of the flanges 51, in this case the lower flange, and the tongue 48 that they also comprise is formed by a return in angle of the other of these edges 51, in this case the

upper edge.

  In the embodiment shown, in addition to the bore 42, the auxiliary support 40 further comprises, on its plate 50, a network of recesses 53, each elongated in

buttonhole shape.

  Two of these recesses 53 extend from the bore 42, being aligned with one another along a

horizontal diameter of the assembly.

  Four more extend along the side edges of

plate 50.

  Six others extend in radius around the hole 42,

away from it.

  For the implementation of the auxiliary support 40, it

  can for example be carried out as follows.

  Initially, the box 41 is attached to

  this auxiliary support 40, using the fixing member 43.

  For example, and as shown, this fixing member 43 comprises two parts 43 ′, 43 ", which, in screwing relation to one another, are suitable for allowing the bottom 54 of the box to be pinched 41, by intervening, one, on a first side of this bottom 54 and of the plate 50 of the auxiliary support 40, the other, on the other side of this bottom 54 and of

this plate 50.

  Once the box 41 is in place on the auxiliary support 40, and once the derivative electric cable 16 engaged in the box 41 by means of one of the end pieces 55 which the latter presents laterally for this purpose, as shown in FIG. FIG. 21, the auxiliary support 40 thus carrying the box 41 is engaged, at an angle, by its tabs 47, in the buttonholes 44 of the bypass support 18 previously put in place on the cable tray 10, then, along arrow F of this figure 21, it is folded over this bypass support 18 until, by elastic deformation of the flange 51 carrying the tongue 48, it engages, by this tongue 48, under the hook 45 of the bypass support 18 ,

  as shown in Figure 16.

  Of course, the present invention is not limited to the embodiments described and shown, but

  includes any variant.

Claims (25)

  1. Bypass support, in particular for cable tray (10) made of wires, of the type comprising an aperture (20A), which, having a generally circular outline, is suitable for installing a sheath (19), characterized in that that said aperture (20A) is intersected by at least one other aperture (20B) of radius (RB) different from hers (RA).   2. Bypass support according to claim 1, characterized in that, for at least one of the openings (20A, 20B), the arc of a circle (27A, 27B) which defines its outline   extends, albeit cumulatively, over 180.   3. Bypass support according to claim 2, characterized in that the angle at the center (AA, AB) subtended by the arc of a circle (27A, 27B) defining the outline of an aperture   (20A, 20B) is between 180 and 260.   4. Bypass support according to any one of   Claims 2, 3, characterized in that, for each of the   openings (20A, 20B), the arc of a circle (27A, 27B) which defines it   the outline extends over 180.   5. Bypass support according to any one of   Claims 1 to 4, characterized in that it comprises at least two sets (J) of cutouts (20A, 20B).   6. Bypass support according to claim 5, characterized in that at least one of the sets (J) of openings (20A,   20B) belongs to a breakable portion (29).   7. Bypass support according to claim 6, characterized in that the two openwork sets (20A, 20B) are staggered in height, with, between them, a line of least resistance (30) delimiting two stages (31, 29 ) of which a form the breakable portion (29).   8. Bypass support according to claim 7, characterized in that it comprises, at a distance from each other, at least two sets (J) of openings (20A, 20B) at each of its floors (31, 29).   9. Bypass support according to any one of   Claims 1 to 8, characterized in that, made of sheet metal,   and being in the general form of a square, it has two wings (22, 24), one said here horizontal, the other said here vertical, at least one of which comprises at least one foldable tab (25) for fixing the assembly to a cable tray (10).   10. Bypass support according to claim 9, characterized in that each of the wings (22, 24) comprises at minus a foldable tab (25).   11. Bypass support according to any one of   Claims 9, 10, characterized in that the openings (20A,   20B) affect the vertical wing (24).   12. Bypass support according to any one of   Claims 9 to 11, characterized in that the horizontal wing   (22) forms a groove (34) at its connection to the wing vertical (24).   13. Bypass support according to any one of   Claims 9 to 12, characterized in that, for snap-fastening   on a longitudinal wire (11) of the cable tray (10), the vertical wing (24) has, projecting, at an angle, on its face internal, a tongue (35).   14. Bypass support according to any one of   Claims 9 to 13, characterized in that the vertical wing   (24) has various recesses (38, 39), such as at least one   hole (38) and / or at least one buttonhole (39).   15. Bypass support according to the claims   7 and 14, taken together, characterized in that the line of least resistance (30) passes through at least one recess (38, 39). 16. Bypass support according to claim 15, characterized in that, at least one of the foldable legs (25) that comprises the vertical wing (24) being formed by means of a puncture (26) thereof. ci, the line of least resistance   (30) also goes through this flat (26).   17. Bypass support according to any one of   Claims 1 to 16, characterized in that it is adapted to   receive, on request, an auxiliary support (40), which, for the installation of a box (41), has a bore (42) suitable for the passage of the fixing member (43) necessary for the fixing this box (41).   18. Bypass support according to claim 17, characterized in that there is provided, between it and the auxiliary support (40), complementary fitting means making it possible to attach it by simple snap-fastening this support auxiliary (40).   19. Bypass support according to claim 18, characterized in that said fitting means comprise, on it, at least one buttonhole (44), and, at a distance therefrom, a hook (45) directed towards this buttonhole (44), and, on the auxiliary support (40), at least one tab (47), for cooperation with the buttonhole (44), and, at a distance from this tab (47), for cooperation with the hook (45) , a   tongue (48) directed in the opposite direction to the tab (47).   20. Bypass support according to the claims   9 and 18, taken together, characterized in that the buttonhole (44) and the hook (45) affect the vertical wing (24). 21. Bypass support according to claim 20, characterized in that the hook (45) is formed by a fold of the free edge of the vertical wing (24), which, in the form of a stick, protrudes on the external face of this vertical wing (24), and the buttonhole (44) extends in the vicinity of the horizontal wing (22).   22. Bypass support according to any one of   claims 18 to 21, characterized in that it comprises,   distance from each other, two buttonholes (44), and the auxiliary support (40) comprises, in correspondence, two legs (47).   23. Bypass support according to any one of   claims 18 to 22, characterized in that the support   auxiliary (40) is made of sheet metal and comprises, on the one hand, a plate (50), which has the bore (42), and, on the other hand, along two opposite edges of this plate (50), two ledges (51), through which the means are formed   corresponding fitting (47, 48).   24. Bypass support according to the claims   19 and 23, taken together, characterized in that the tab (s) (47) which comprise said interlocking means are formed by angled returns from one of the flanges (51), and the tongue (48) which also comprise these interlocking means is formed by a square back to the other of these edges (51).   25. Bypass support according to any one of   Claims 17 to 24, characterized in that the support   auxiliary (40) comprises a network of elongated recesses (53) each in the shape of a buttonhole.