FR2756302A1 - IMPROVEMENT TO SAFETY BARRIERS - Google Patents

Abstract

The object of the present invention is to create a new device for connecting temporary barriers made up of successive barrier elements which separate a traffic lane from another traffic lane or from a site or land. A movable road safety barrier element (1) is provided at each longitudinal end (11, 12) with a covering and interlocking connecting means, and comprises an integrated longitudinal connecting member (3, 4). The technical field of the invention is that of the manufacture of separating elements (or sections or modules), particularly metallic separating elements, intended for the construction or temporary installation of mobile or movable safety barriers (or barriers). on and / or along a roadway.

Description

IMPROVEMENT TO SAFETY BARRIERS

  The present invention relates to the creation of a new device for connecting the temporary barriers consisting of successive barrier elements that separate a traffic lane from another lane or a building site or land. The technical field of the invention is that of the manufacture of separating elements (or sections or modules), particularly of metal separating elements, intended for the construction or the temporary laying of safety barriers (or slides).

  movable or moveable on a roadway and / or along it.

  These barriers have the function of preventing the exit of a vehicle during an accident. The impact of a vehicle against a barrier results in significant forces, in particular lateral bending and longitudinal traction, which the

  separator sections and their junctions (or links).

  As an indication, the barriers must be able to withstand the lateral impact, at an angle of incidence close to 20 degrees, of a motor vehicle of a mass close to

  13 tons launched at a speed close to 70 km / hour.

  The resistance of the connection between two consecutive elements of a. barrier (horizontal) lateral bending forces during an impact, is generally obtained through an overlap zone of a male end (forming a sleeve) of a section by a female end (forming a sheath) of a adjacent stretch; EP 452 893 (SPS SCHUTZPLANKEN GMBH) describes such sections; the covering is obtained by fitting sections (that is to say by interlocking along the longitudinal axis of the sections) previously aligned; such a fitting is generally carried out with a transverse or radial clearance, that is to say does not constitute a tight or forced fitting which would require the application of a longitudinal force of fitting; therefore in order to withstand the longitudinal tensile forces (in case of shock), which without other means of connection would cause the dislocation of two consecutive elements and their disengagement (they are also generally not fixed to the ground), are generally provided with a key (or pin or pin) and / or bolts, which are generally arranged in the overlap area of the two

  ends of the two consecutive sections.

  These bolts or keys, whose longitudinal axis generally extends in a plane (vertical) perpendicular to the longitudinal axis of the sections, are biased to shear, when longitudinal forces (traction) are applied to the barrier sections; in order to support these shear forces, it is necessary to multiply the number of bolts or keys and / or increase their section; in the case of using a key, it is also necessary to multiply the number (as is the case in patent EP 452893) and / or increase the section of the keyway orifices that are provided in each end part of the sections, to prevent tearing

  and / or tearing by shear forces.

  The essential disadvantage of lap joints in which the longitudinal tensile strength is provided by keys and / or bolts, is on the one hand the complexity of the solutions to provide sufficient resistance to shear forces, and on the other hand the fact that the many bolts and keys can be lost or forgotten on the road and can therefore constitute a significant danger for users of vehicles traveling on the road; the invention proposes to remedy these drawbacks and also aims to minimize the time required for the operations of joining and disconnecting sections between them, and to facilitate these operations; this last objective is essential, since each section having a length of the order of 1 to 5 meters, the realization of a barrier of 1 km of

  length requires the linking of 200 to 1000 sections placed end to end.

  The invention consists in providing a slider element or road safety barrier element, which is able to be placed on the ground, which is provided at each longitudinal end with connection means by overlap and interlocking, with a sleeve (or connector) or with another slide element, and which comprises a longitudinal connecting member, that is to say an axial stop means resistant to longitudinal traction, which is integrated that is to say which is part of the element and / or is rigidly connected to each end of said slide member; thus a male longitudinal link member integrated with a slide member can be coupled to a female member (corresponding to the male member) of longitudinal connection, which is provided on an adjacent slide member (or on a connecting sleeve of two adjacent slide members), by the end-to-end placement and alignment position of the two adjacent barrier members (or the barrier member and

a sleeve).

  Preferably, the integrated longitudinal stop means forming part of the interlocking connection means provided at each end of the slide element, allow the relative immobilization along their longitudinal (common) axis of two consecutive barrier elements (or else a barrier element or a sleeve), with a small longitudinal clearance in the nested position; preferably, the ratio of the longitudinal clearance of a link (expressed in meters) in the nested position to the length (expressed in meters) of a barrier section is between. 2 x 10-4 and 8 x 10-4, preferably of the order of 4 x 10-4 to 7 x 10-4, or as an example of

  two millimeters for a stretch of four meters in length.

  Preferably, these integrated longitudinal stop means comprise at least one portion such as a rib projecting from an internal face of a side wall of a female connecting member (or sleeve) and comprise a recessed portion such that a groove, provided on an outer face of a side wall of a male connecting member (or sleeve); the hollow parts and the projecting parts are for example obtained by welding a bar-shaped part on the side walls of the male and female connecting members, or are obtained by deformation of a part

  said walls (for example obtained by stamping).

  Thus, during longitudinal traction on the connection of two barrier elements (tending to separate the elements), the longitudinal stop means respectively integrated in the sleeve and in the sheath are supported on one another by faces of contact disposed opposite one another and according to a large contact area, which

  allows the connection to withstand significant longitudinal tensile stresses.

  The barrier element junction according to the invention also makes it possible to provide a mechanical connection whose performance is close to a connection by embedding.

  therefore more resistant than current junctions.

  This connection system can also be placed at the end of concrete separators. Known assemblies of modular separators have other important disadvantages: in a key assembly, the joint creates a possible rotation between one element and the next element and causes a large lateral deformation (sometimes called dynamic or static arrow or width of operation) of a barrier during vehicle impacts; this deformation takes such a magnitude that it is no longer admissible during the impact of heavy vehicles; in addition, as soon as the clearance between key and holes is reduced to a few millimeters, the placing of the holes face to face is difficult, and consequently the introduction and / or the release of the

Cylindrical key is difficult.

  Similarly, in a bolted connection, the clearance between bolts and the holes provided in the end walls of the sections creates a possibility of rotation between a separator and the next separator. This rotation causes a large deformation during vehicle shocks; moreover, the assembly or disassembly time of a link is high because of the number of bolts (20 to 30 screws and nuts to be put in place and to screw) and immobilizes a whole team of installation and its equipment which awaits the end of the bolting one element before mounting the next; placing screw holes face-to-face is difficult and causes a waste of time. According to preferred embodiments of the invention: - the barrier element comprises overlapping connection means and interlocking provided at each end of the slide element, which means are designed to allow a transverse interlocking, preferably vertical two adjacent barrier elements or a barrier element and a connecting sleeve; thus, the interlocking of two consecutive barrier elements is obtained by a relative displacement of a first connection means provided at one end of a barrier element with a second connection means provided at one end of a second element, in a transverse path (with reference to the longitudinal axis of the barrier elements) which is preferably rectilinear and vertical, so that said movement can be effected by means of a hoist or a crane to which is suspended a barrier element; for this purpose, preferably, one end of the element comprises a female element (hollow) connecting (or sheath) provided with a peripheral opening allowing the transverse interlocking and the overlap of a male connecting element (or sleeve ) by the female connecting element; each end of the slide element comprises means of guiding and / or longitudinal centering, that is to say relative longitudinal positioning of a slide element relative to another adjacent slide element, during the movement of the slide element. interlocking two consecutive slide elements; the barrier element comprises a female interlocking connection element (or sleeve) which essentially consists of flat walls or facets constituting a tubular duct of horizontal axis and of open polygonal transverse profile, preferably of substantially trapezoidal; the duct is provided with an opening or cut provided on one of its faces (for example its large substantially horizontal base) situated in the lower part of the female connecting element; this peripheral cut allows the introduction of the male member into the duct or sleeve during vertical nesting movement; the barrier element comprises a locking member in the nested position, which is separable from the barrier element, such as one or more bolts, or which is integrated with the barrier element, and prohibits a transversal (vertical) movement of dislocation; at least one face, preferably at least two lateral faces of the female connecting element, comprises a second locking member which is separable from the barrier element, for example constituted by one or more bolts ( s), or which is integrated in the barrier element, and in this case for example consisting of one or more lugs (s) adapted to cooperate with one or more cavity (s) provided (s) on the element connecting male, to prevent deformation of the female connecting element in the vicinity of the opening provided in the lower peripheral portion thereof, and in particular to prevent the separation of the side walls of the female connecting element under the effect of a shock; the barrier element comprises means for guiding and / or centering in the relative longitudinal position of two consecutive barrier elements; these means may comprise two symmetrical parts or ribs symmetrical with respect to a substantially vertical axis, and forming a prominent wedge (whose tip is located in the lower part) provided on the internal face of a side wall of a female connecting member ; these means further comprise at least one groove of substantially vertical axis, which groove is of decreasing section (from top to bottom), and preferably symmetrical with respect to a substantially vertical axis, for example constituted or defined by two bars or ribs inclined relative to one another at an angle substantially equal to the opening angle of the prominent corner provided on the side walls of the female member, which groove is provided on the outer face of the side walls of the male link member; alternately, symmetrically or inversely, the guide and centering wedge can equip the male member or sleeve, and the corresponding groove equips the female member or sheath; in this case, the point of the wedge is directed upwards, and the section of the groove is increasing from top to bottom; - The barrier element is essentially constituted by a hollow beam of substantially constant cross-section and / or transverse inertia, provided with one or more longitudinal stiffener (s), is made of metal (for example in galvanised steel

  folded) and / or plastic and / or concrete.

  The invention provides many advantages: - the invention provides a rigid connection and little deformable under the shock due to the rigidity of the connector; - The invention provides a very strong connection, the force can be transmitted by interlocking on the large surfaces in contact is greater than the force that can transmit a separator. The system brought to break will break by breaking the separator in current section and not on the link. The strength of the separator is used at 100% in both tensile and bending; - Thanks to the casing of the parts or connecting members which slide transversely (preferably vertically) on their outer faces, the invention allows the direct assembly by descent of the brought element, according to a very simple and fast movement to achieve using a lifting device, unlike the introduction of the connector usually made by a horizontal translational movement of two sections placed on the ground; the invention allows for the same reasons rapid disassembly by lifting an element to separate it from the adjacent element placed on the ground; - The trapezoidal shape of the cross section of the connector ensures automatic alignment of the new element which is guided on the previous and aligns with him; - The trapezoidal shape of the recess provided on the side of the connector and the projection provided on the side of the separator brings the new element posed by downward movement to its final location relative to the previous with a very small human intervention; - An upper bolt (or first locking member) ensures the blocking and eliminates the game, or limits the game to a value in the preferred value range indicated above, for example by slightly unscrewing the upper bolt on each side. of the junction, which gives play, and allows to create an articulation; the lateral movement of spacing of the flanges of the sheath is blocked immediately during installation, by the lugs (or second locking members); alternatively or in addition, two bolts can be added at the bottom to avoid disruption during very violent shocks where the separator could be twisted; - the separate parts (detachable from the slide) for fixing and / or locking to be screwed or transported by the technicians, are reduced to 3 bolts by connection to the

  maximum, and may be totally eliminated if necessary.

  The many advantages provided by the invention will be better understood at

  through the following description which refers to the accompanying drawings, which illustrate without

  no limiting character of the preferred embodiments of the invention.

  Unless otherwise indicated, the identical numerical references in the different

  Figures, designate identical or similar elements.

  Figure 1 shows, in the lower part, the assembly connector in perspective with the projections on a single side face limiting the hollow shape; FIG. 1 represents, in the upper part, the assembly nozzle of the separator

  in perspective with the internal projections drawn on two lateral faces.

  FIG. 2 shows the separator with its assembly ends in

  perspective and two connectors on which it can fit down.

  Figure 3 shows the assembly connector and separator assembled.

  FIG. 4 is a view along IV-IV of FIG. 3 and is a sectional view of the

connection by a horizontal plane.

  FIG. 5 schematically illustrates, in side view, a barrier being mounted, according to a second embodiment, comprising two elements assembled and placed on the ground and an element suspended in a position allowing interlocking.

  by a downward vertical movement.

  Figures 6 and 7 are respectively views according to VI and VII-VII of the

figure 5.

  In a first embodiment illustrated in FIGS. 1 to 4, the assembly of two identical rigid elements 1 of barrier is carried out by a connector or sleeve 2

  rigid fitting into each of them.

  In this embodiment, the barrier comprises a separate connection connector of two consecutive separator elements, and therefore comprises (to the nearest unit) as much

  connectors than separator elements.

  The rigid elements 1 to be assembled or "separators" are shaped to present at each of their two ends a sleeve of identical shape in tube, open (mark 15) on its entire lower face, and intended to cover the "connector" 2 during 'a

  movement of setting up the separator by descent.

  The connection sleeve has a tube shape (solid or hollow) that comes

  cover down the complementary tube shape of the end of the separator.

  Once the separator 1 descended according to the vertical arrow 8 on the connector 2, the connector could slide longitudinally in the separator. To prevent this movement is provided on the outer face of each side flank 21, 22 of the connector, a substantially vertical hollow form 3. This hollow form receives a shape 4 projecting substantially vertically existing inside on each lateral flank 17, 18 of

  the recess or end sleeve of the separator 1.

  The contact and the support of the bars 41, 42 fixed to the walls 17, 18 of the separator 1, by their external lateral faces, on the inner lateral faces 3a and 32a of the bars 31 and 32 fixed to the walls 21, 22 of the connector 2 , thus ensures a connection resistant to longitudinal traction (along the axis 9); the support of the side walls disposed opposite 17, 21, respectively 18, 22 of the separator and the connector, via the

  bars 31, 32, 41, 42 provide a connection resistant to lateral bending.

  This form is not only resistant to disassembly by lifting, a bolted connection 52, 53 is provided at the top to prevent the lifting of the separator

  1 relative to the connector 2 in case of impact.

  If they are subjected to a lateral bending force, (along the horizontal transverse axis 91) the extreme lower edges of the walls 17, 18 of the sheath of the separator tend to deviate due to the presence of the blank 15; to prevent this movement, a bolt 62, 63 for lateral attachment to each side face 21, 22 of the connector is provided; alternatively two lugs 71 protruding from the separator can come jam in a reservation (port 72) provided on the connector. The two solutions are described and marked in FIGS. 1 to 3, whereas only one is sufficient to ensure

function.

  To align the last element placed with the previous, the section of the connector is flared, preferably trapezoidal, and narrower at the top. By the simple movement of descent, the separator 1 is aligned with the previous one with a

  very small human intervention.

  To precisely position the last element placed relative to the previous one, the recess or groove 3 provided on the side of the connector and delimited by the bars 31, 32 is wider upwards, and the corresponding projection 4, 41, 42 provided on the separator 1 is narrower in its lower part. Thus by the simple descent movement 8, the separator 1 is positioned at its defminitive location relative to the previous one with a very small human intervention; preferably a weak game

  longitudinal is kept in the position of stop (nesting).

  The separate connection element (or connector) shown in FIGS. 1 to 4 connects two consecutive separators such as that marked 1. The connector 2 is composed of a

  metal tube (or a solid piece or metal profiles welded together).

  The separator 1 comprises at each of its longitudinal ends a reservation composed of a metal tube (or an extruded part or metal profile welded together), constituting a sheath open over its entire lower face 15 intended to cover the connector 2 during a movement of setting

separator in place by descent.

  The connector has on the outside on each side a hollow shape or substantially vertical groove 3 intended to receive the male portion 4 which slides inside the groove. The hollow form 3 is made and / or limited by two bars 31 and 32 fixed inclined with respect to a median axis and / or symmetry 94 which is parallel to the plane of the wall 22; the bars 31, 32 which are inclined relative to each other by an angle 102, for example between 5 and 45 degrees, thus delimit a groove 3 whose section decreases from top to bottom. The operating principle remains valid if one of the bars 31 or 32 is vertical. The operating principle remains valid if the two bars 31 and 32 are vertical, the introduction of part 4 would be

  however more difficult and part 4 should be beveled at its low end.

  In a complementary manner, the separator 1 comprises on the inside of each flank a substantially vertical protruding form 4 intended to slide in the female part 3 of the connector. The projecting shape 4 is limited by the bars 41 and 42 fixed inclined with respect to a median axis and / or symmetry 93 which is parallel to the plane of the wall 18; the bars 41, 42 which are inclined with respect to one another by an angle 101 preferably equal to the angle 102, for example between 5 and 45 degrees, thus constituting a rib 4 whose section decreases by top to bottom. The operating principle remains valid if one of the bars 41 or 42 is vertical. The operating principle remains valid if only one of the vertical bars 41 or 42 is provided, the introduction of part 4

  in part 3 being more difficult.

  The hollow form 3 can also be obtained by machining a connector consisting of a solid piece not hollowed out; the projecting shape 4 can also be obtained by machining a single piece consisting of a solid non-recessed piece going from the outer edge of

  the piece 41 at the outer edge of the piece 42.

  The bars 31, 32 (respectively 41, 42) are fixed by welding (or any other suitable means such as bolting) on each side of the connector 2

(respectively of the separator 1).

  The locking relative vertical movements of the separator relative to the connector, is provided by a connection marked 5 Figure 3 in the upper part. It is made by an oblong hole 51 made in the upper horizontal wall of the sheath It passes a bolt 53 which is screwed into a round threaded hole 52 provided in the

  upper horizontal wall 24 of the connector, as shown in Figures 1 to 3.

  This first locking can be realized, in the case of a hollow connection tube, with a reinforcing plate and a bolt welded to the back or a welded reinforcing plate with a threaded hole directly in the reinforcing plate as shown

figure 1.

  The blocking of the separation of the cheeks of the separator is ensured by a link in the lower lateral part marked 6. It is realized by a threaded round hole made in the lateral part 62 in which is screwed the bolt 63 passing through an oblong hole 61 provided in each side wall 17, 18 of the separator. The piece 62 can be made in the case of a hollow connection tube with reinforcing plate and a bolt welded to the back or a reinforcing plate welded with a threaded hole directly into the reinforcing plate

as shown in FIG.

  The blocking of the separation of the cheeks of the separator can also be ensured by a link in the lower lateral part marked 7. It is realized by a reservation pending 72 receiving the lug 71 of the separator; the lug of the separator is pointed or beveled for

  facilitate assembly during descent 8 as shown in Figures 1 and 2.

  A first element overlapping a connector is placed on the ground, the connector protruding waiting for the next element. A second element is lifted by a lifting gear and one of its longitudinal ends is presented above the

  connector pending, then the second element is lowered to cover.

  During the downward movement, the trapezoidal shape of the narrower connector section in the upper part imposes on the separator being laid a

  alignment with the previous element without manual intervention.

  During the downward movement the trapezoidal shape of the protrusions on the sides of the wider connector at the top places the separator being laid at the

  exact distance from the previous item without manual intervention.

  Once the new element is installed the lifting gear can be immediately released to achieve a new cycle; the immediate recess is a significant improvement allowed by the invention in the previous systems bolted by plates the lifting gear must remain active to bring by successive movements all the holes of the many bolts facing each other. The step can not intervene

  that once the bulk of the bolts put in place.

  After separation of the separator and release of the hoist the link is

  completed by a technician who then screws the upper bolt 53 and the two bolts 63.

  The efforts developed during the clamping completes the alignment of the last element placed. The screwing of the bolts can be carried out by hand on the beginning of the race and

  must be made to the key that in their last millimeters of race. With reference to FIGS. 5 to 7 which illustrate a second mode of

  embodiment of the invention, the barrier illustrated in FIG. 5 is in this case obtained by the end-to-end fitting of the barrier elements 1 with a mutual overlap zone 100 between two consecutive barrier elements, without the use of a separate connecting sleeve.

  intermediate as is the case in the embodiment illustrated in Figures 1 to 4.

  In this case, as illustrated particularly in FIG. 7, each barrier element 1 comprises, at its first longitudinal end 11, a female member 13 or connecting sleeve, and comprises at its second longitudinal end 12 an element

male or connecting sleeve 14.

  All the elements 1 of the barrier are identical, and the sleeve 13 of the barrier element 1 shown in FIG. 5 is able to engage by a descending vertical translation movement (according to the arrow indicated in FIG. 5) around the sleeve 14. equipping the barrier element 1 already laid on the ground, until coming into a position of engagement of the sleeve 14 in the sleeve 13 and covering the sleeve by the sheath, that is to say causing a partial recovery of two elements of

  consecutive barriers over a length or area marked 100 Figure 5.

  For this purpose, the male part or sleeve 14 provided at the end 12 of the element 1 has a lateral narrowing 103 whose value is at least equal to the thickness 104 of the end portion of the side walls 18 of the sheath female 13, to allow free sliding of the side walls 17, 18 of the sleeve 13 along the outer faces of the side walls 21 and 22 of the male sleeve 14 of the adjacent element, during the

  downward movement (marked 8 figure 5).

  Guiding and longitudinal positioning of two elements relative to each other during this fitting operation in a transverse direction, is performed by cooperation of the projections 4 or vertical ribs provided on the inner faces of the side walls 17 , 18 of the sleeve 13 with the vertical recessed grooves 3

  provided on the outer face of the side walls 21 and 22 of the male sleeve 14.

  This vertical interlocking operation is made possible by means of a cutout or opening 15 provided, in line with the female sheath 13, in the horizontal bottom wall or base 105 of the element 1 by which the element 1 may for example rest on the ground, which opening 15 is defined in particular by a ridge 16 provided in the

bottom wall 105.

  In the case where the side walls 17 and 18 of the sleeve 13 have a certain elasticity, the locking means preventing the vertical extraction or lifting of one element relative to another may be obtained by tabs or claws, as identified 54 Figures 6 and 7, which are adapted to be housed in the lower part of the side walls 21 and 22 of the male sleeve which is covered by the sleeve, at the end of interlocking race, thanks to a cavity or recess (such 55 (5) provided in the lower part of the side walls 21, 22; the integrated legs 54 can be

  obtained by folding a tongue provided at the lower end of the walls 17, 18.

Claims (10)

  1. Element (1) movable road safety barrier, which is provided at each longitudinal end (11, 12) connecting means by overlap and interlocking, characterized in that it comprises a member   (3, 4) integrated longitudinal link.   2. Barrier element according to claim 1 wherein the overlap connection means provided at each end of the element allows a transverse interlocking, preferably vertical, two adjacent barrier elements or an element (1 ) and a connecting sleeve (2), and preferably the connecting and overlapping connection means comprise a female connecting element, or sheath, provided with a peripheral opening (15) allowing the transverse interlocking and the overlap of a male element of   connection, or sleeve, by the female connecting element.   3. Barrier element according to any one of claims 1 or 2 in   wherein each end of the member has integrated means (3, 4, 31, 32, 41, 42) for relative longitudinal positioning of a slide member relative to another adjacent slide member, upon movement   interlocking two consecutive slide elements.   4. Barrier element according to any one of claims 1 to 3 in   which each end of the element comprises abutment means (3, 4)   integrated longitudinal, with longitudinal play.   5. Barrier element according to any one of claims 1 to 4   comprising a female element (or sleeve) of overlap connection and interlocking provided with an opening (15) or cut in its lower part, which female connecting element is preferably of substantially trapezoidal section and is provided with an opening or cut provided on its large base substantially horizontal and located in the lower part of the female connecting element.   A barrier element according to any one of claims 1 to 5 which   comprises a first locking member in a nested position, such as a bolt (53), which prohibits a transverse (vertical) disengagement movement, and in which at least one lateral face of a female connecting element comprises a second locking adapted to cooperate with a male connecting element, to prevent the deformation of the female connecting element in the vicinity of an opening provided in the part   lower peripheral of this one.   7. Barrier element according to any one of claims 1 to 6 which   has at least one portion (such as a rib) projecting from an inner face of a side wall of a female connecting member or sheath, and has a recessed portion (such as a groove) provided on a external face of a side wall of a male connecting member or sleeve, which recessed parts and projections are obtained by welding a bar-shaped part on the side walls of the male and female connecting members, or are obtained by deformation of a part said walls.   8. Barrier element according to any one of claims 1 to 7 which   has integrated means for guiding and centering relative longitudinal position of two consecutive barrier elements, which guide means comprise two parts or ribs (4, 41, 42) protruding symmetrical with respect to a vertical axis and forming a prominent corner, which are provided on the internal face of a side wall (17, 18) of a female connecting member, and the guide means further comprise at least one groove (3, 31, 32) of vertical axis, which groove is of decreasing section and symmetrical with respect to a vertical axis, for example constituted by two bars or ribs (31, 32) inclined relative to each other by an angle substantially equal to the opening angle the prominent corner provided on the side walls of the female member, which groove is provided on the outer faces of the side walls of the organ male bond.   9. Barrier element according to any one of claims 1 to 8 which is   essentially constituted by a hollow beam provided with one or more   stiffener (s) internal (s) longitudinal (ux).   10. Barrier element according to any one of claims 1 to 9 which is essentially metallic.