CRASH BARRIER

Abstract: A crash barrier has an upper profile girder (1) of hollow, approximately oval cross section and a longitudinal opening on the underside. A number of posts (2) secured in the ground extend, with upper end portions (4) up through the opening. Along opposing edges (5 and 6) of the opening, the profile girder (1) has upwardly directed flanges (7 and 8, respectively). Anchorage members interconnect the posts (2) with the profile girder (1) and include support members (21) which abut against the underside of the profile girder (1) at the edges (5 and 6) of the opening and catch members (22, 23 and 34) which engage with the upper edges of the flanges (7 and 8) or with the inside of the profile girder (1) at the edges (5 and 6) of the opening. The engagement between the anchorage members and the profile girder (1) is disposed to break in the event of a collision, while joints between adjacent sections of the profile girder withsand such a collision.

Description: CRASH BARRIER TECHNICAL FIELD The present invention relates to a crash barrier comprising a number of posts secured in the ground and a hollow profile girder connected to them and having a longitudinal, downwardly directed opening, upper end portions of the posts extending up thorough the opening to the interior of the profile girder and being connected thereto by means of connection members. BACKGROUND ART Crash barriers are previously known in a multiplicity of different versions. If the crash barriers are placed along a carriageway between it and the surrounding terrain, the crash barriers will be asymmetric inasmuch as a deflector girder is placed on the side of posts supporting the deflector girder. Such a construction functions satisfactorily with the above-mentioned placing of the crash barrier, but cannot be employed if the crash barrier is to be placed between two adjacent carriageways with counterflowing traffic. In such a situation, two separate crash barriers will be needed with the "rear side" facing one another. So-called wire crash barriers are previously known which consist of a number of posts at whose upper end regions are secured a number of wires which are placed superjacent one another approximately parallel with the ground. Principally for reasons of cost, such wire crash barriers have become increasingly common, both placing between adjacent carriageways or traffic lanes with counterflowing traffic and between a carriageway and the surrounding terrain. The above-mentioned wire crash barriers may function well in the event of a collision with motor cars and other vehicles where the passengers and driver sit protected. If, on the other hand, such wire crash barriers are in collision with an unprotected road user, for example a motorcyclist, they are extremely hazardous because, on the one hand, of the slight dimensions of the wires and, on the other hand, because of sharp and projecting end regions and side edges of the posts employed. Wire crash barriers have even been banned in certain countries because of such risks. PROBLEM STRUCTURE The present invention has for its object to design the crash barrier intimated by way of introduction such that it will be suitable for placing between adjacent carriageways or traffic lanes with counterflowing traffic. The present invention also has for its object to realise a connection between an upper profile girder included in the crash barrier and posts supporting it which is such that the crash barrier outwardly presents uniform, smooth surfaces without sharp and projecting portions which might possibly injure an unprotected road user. Further, the present invention has for its object to design the crash barrier such that an upper profile girder included therein affords a gentle retardation and arrest without recoil of a colliding vehicle. Finally, the present invention has for its object to realise a crash barrier which in an improvement on prior art designs and constructions both as regards cost and aesthetic properties. SOLUTION The objects forming the basis of the present invention will be attained if the crash barrier is characterised in that the connections between the posts and the profile girder are disposed to break within a collision area in the event of a collision against the crash barrier. Further advantages will be attained according to the present invention if the crash barrier is also given one or more of the characterising features as set forth in appended Claims 2 to 20. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will now be described in greater detail hereinbelow, with particular reference to the accompanying Drawings, in which: Fig. 1 is an end elevation of a crash barrier designed according to the present invention; Fig. 2 shows the crash barrier of Fig. 1 seen from beneath; Fig. 3 shows an end elevation of a section of a crash barrier in the region of a joint between two adjacent sections; Fig. 4 shows, in a view corresponding to that of Fig. 1, an alternative embodiment of the present invention; Fig. 5 shows, in a view corresponding to that of Fig. 2, the embodiment according to Fig. 4; Fig. 6 shows, in a view corresponding to that of Fig. 1, a modified embodiment of the present invention; Fig. 7 shows a catch member included in the embodiment according to Fig. 6; and Fig. 8 shows a support member included in the embodiment according to Fig. 6. DESCRIPTION OF PREFERRED EMBODIMENTS It will be apparent from Fig. 1 that the crash barrier includes a top bar or profile girder 1 which is supported by a number of posts 2 of which one is intimated in the Figure. It will further be apparent from the Figure that the profile girder has an outwardly convex, gently arched or rounded cross section which is of greater width in the horizontal direction than applies to its height in the vertical direction. The post 2 connects to the profile girder from beneath and is connected to the profile girder in the central region thereof seen in the width direction of the profile girder. As a result, the profile girder will, in the width direction, laterally extend outside the posts 2, whereby the crash barrier will be particularly suitable for placing between two adjacent carriageways or traffic lanes. The cross section of the profile girder 1 has a circumscribed contour line which follows the outer surface of the profile girder. As will be described in greater detail below, the profile girder has a longitudinal opening 3. In the region of the opening, the circumscribed contour line is to be considered as a "natural" extension of the contour lines on either side of the opening 3, so that these extended contour lines meet without discontinuities in the region of the opening 3. The profile girder 1 is of the width in the horizontal direction which is approximately twice as great as the extent of the post 2 in the same direction, but may possibly be somewhat wider. Further, the width of the profile girder is of the order of magnitude of 1.5 to 1.7 times greater than its height. Finally, its cross sectional configuration is hollow and oval or approximately elliptical and it has a smooth outside without marked projections, folds or other irregularities. As was intimated above, the profile girder 1 has (in the position of use) on its underside a longitudinal opening 3 (see Figs. 2 and 3) through which upper end portions 4 of the posts 2 supporting the profile girder 1 extend up to the interior of the profile girder 1. The opening 3 is laterally defined by flanges 7 and 8, respectively, which are disposed along the opposing edges 5 and 6 of the opening 3 and which extend up to the interior of the profile girder. The flanges are planar and are approximately parallel with one another and with a longitudinal central vertical plane in the assembled state of the crash barrier. The two flanges 7 and 8 extend upwardly approximately to half of the vertical extent of the profile girder 1, or possibly somewhat more. On either side 5 and 6 of the longitudinal opening 3, the flanges 7 and 8 merge into lower surfaces of the profile girder, these lower surfaces extending laterally out from the opening 3. As will be described in greater detail, upper and lower edge portions of the flanges 7 and 8, as well as the lower surfaces of the profile girder 1, serve the function of engagement portions for the connection members by means of which the posts 2 are connected to the profile girder. These connection members are at least partly, and in one embodiment to a substantial degree, placed inside the circumscribed contour line of the profile girder. As a result, it will be perceived that the outwardly exposed surface of the crash barrier, or at least the profile girder 1 and its connections with the posts 2, have no projecting or sharp details or fittings which could possibly injure an unprotected road user in the event of a collision. Moreover, the crash barrier will be aesthetically attractive with a "clean" outer surface. The posts 2 display per se conventional cross sectional configuration with two parallel, opposing side surfaces 9 and 10 which between them have a web 11 which is largely V-shaped in cross section. As a result, the post 2 will have a cross sectional configuration which is reminiscent of a W or an ∑. On the opposite side of the web 11, the side edges 10 and 9 of the post have flanges 12 and 13, respectively, which are bent inwardly towards one another so that the interior of the profile of the post will thereby be accessible through an opening 14 lying between the flanges 12 and 13. A crash barrier according to the present invention consists of a plurality of profile girders 1 joined together in a long sequence after each other and all of which, at least apart from the end regions of the crash barrier, have the same cross sectional configuration. In a joint region, which is shown in Fig. 3, a joint profile 15 is inserted interiorly in the profile girder, and has a cross section which is substantially identical to the cross section of the profile girder 1. The joint profile 15 is dimensioned in such a manner that it may be slid, more or less without clearance, into end regions of mutually meeting profile girders 1. The joint profile 15 also has inwardly directed flanges 16 and 17 which, on joining of adjacent profile girders, abut against the outsides of the flanges 8 and 7, respectively, of the profile girders. In terms of mechanical strength, the profile girder 1 is dimensioned to be able to be deformed to a considerable extent and also undergo major changes in cross sectional configuration in the event of a collision. On the other hand, it is important that the profile girder is not wrenched off or joints between adjacent profile girders are broken so that the profile girders have free ends. In order to realise a reinforcement in the joint region between two adjacent profile girders 1 without the cross sectional configuration of the profile girder being stabilised excessively, there are provided, in addition to the joint profiles 15, longitudinal strip irons or plate profiles 18 which abut against the sides of the two flanges 16 and 17 of the joint profile 15 facing away from one another. The plate profiles 18 are of a material thickness which is considerably greater than the material thickness in both the profile girder 1 and in the joint profile 15 and, as a result, may make a major contribution to mechanical strength, in particular tensile strength, in the joint region between two adjacent profile girders 1. The plate profile 18 is of a length so as to extend on both sides of the joint between the ends of adjacent profile girders 1 and has, along its longitudinal extent, a hole pattern in which bolts 19 are inserted which also extend through corresponding openings in the mutually abutting flanges 7 and 17, and 8 and 16, respectively, on the profile girders 1 and joint profile 15. It will be clearly apparent from Fig. 3 that the heads of the bolts 19 are located in the longitudinal opening 3 in the profile girder 1, for which reason they are located inside the circumscribed outer contour of the profile girder. Further, the heads of the bolts are conveniently accessible via the longitudinal opening 3. It will finally be apparent that the plate profiles have, in their openings, threads for accommodating and tightening the bolts 19. It will be apparent from the foregoing that the joint between two adjacent profile girders is disposed in its entirety interiorly in the profile girder. It has somewhat surprisingly proved that the joint between the upper end portions 4 of the posts 2 and the profile girder 1 could be broken in the event of a collision against the crash barrier so that the profile girder 1 will thereby, without breaking, be permitted to be deformed and bent out laterally along a relatively long length, a collision area, which may, depending upon the circumstances, amount to one or a few tens of metres. For this reason, there are no coarse material cross sections in the regions where the posts 2 co-operate with the profile girders 1. The connection members which interconnect the posts and the profile girders have thus substantially the same material thickness as both the posts 2 and the profile girders 1. The connection members include lower support members 21 which, from beneath, abut against the underside of the profile girder 1 on either side of the longitudinal opening 3. As a result, they will co-operate with lower engagement portions along opposing edge portions 5 and 6 of the opening 3 or at or on lower edge portions of the flanges 7 and 8. As has been intimated, the support members 21 extend from the opposing edges 5 and 6 of the opening 3 away from the opening 3 and connect with their upper surfaces to the downwardly directed edge portions of the profile girder adjacent its opening 3. The support members 21 are in the form of flaps or projections which, in the longitudinal direction of the profile girder, have a slight, limited length which is clearly apparent from Fig. 2. Thus, the length extent of the support members in the longitudinal direction of the profile girder is only approximately twice as great as their projection away from the opening 3, i.e. of the order of magnitude of a few centimetres. The connection members further include catch members 22 which engage with the profile girder 1 interiorly therein and, more precisely, with the upper edge regions of the two flanges 7 and 8, i.e. with upper engagement portions on the profile girder 1. The catch members 22 are also of extremely limited extent in the longitudinal direction of the profile girder 1, which is also apparent from Fig. 2. More precisely, the longitudinal extent of the catch members 22 in the longitudinal direction of the profile girder is of the same order of magnitude as the extent of the support members 21 in the same direction. The catch members 22 are disposed at the upper ends of upwardly directed flat profiles or sheet strips 23 which are located between each respective flange 7 and 8 and adjacent sides 9 and 10, respectively, on the post 2. Both the support members 21 and the rods 23 extend downwards a distance under the underside of the profile girder 1 along the opposing side edges 9 and 10 of the post 2. Immediately beneath the profile girder, there is provided a screw union 24 which extends through both the support members 21 and the rods 23. It will be clearly apparent from Fig. 2 that the nuts of the screw union 24 are easily accessible interiorly in the open profile which forms the post 2. In order to prevent the support members 21 from rotating about the screw unions, opposing and lower regions of them have flanges 25 directed towards the post 2 and surrounding lower portions of the rods 23. In order to permit vertical adjustment of the position of the profile girder 1, at least the holes provided for the screw unions 24 in the side surfaces 9 and 10 of the posts are slightly oblong in the vertical direction. In the event of a collision against a crash barrier according to the present invention, it is essential that the barrier may yield without permitting the colliding vehicle to pass through the crash barrier and possibly enter a counterflowing carriageway or traffic lane. However, the deformation must not be so great that it runs the risk of jeopardising the safety of traffic in a counterflowing carriageway or traffic lane. Through the deformations in the crash barrier, an absorption will be effected of the energy of the colliding vehicle so that this is retarded and arrested in a more or less gentle manner. A yieldable crash barrier according to the present invention also entails that the risk that a colliding vehicle uncontrollably recoils out from the crash barrier after a collision is reduced to a considerable degree. According to the present invention, the energy absorption on a collision takes place among other things in two different ways, partly by bending of the profile girder in its entirety and partly by deformation or compression of its cross sectional configuration. In both of these respects, the longitudinal opening 3 located at the bottom is important, since it permits the above-mentioned deformations without weakening the profile girder against tensile, propelling forces. In order that the above-considered energy absorption, i.e. the deformation of the profile girder can take place, it is important , as was mentioned above, that the interconnections between each individual post 2 and the profile girder 1 are disposed to break or be released within a collision area if the crash barrier were to be subjected to a collision. Against the above background, it is vital that the catch members 22, the rods 23 and the support members 21 be considered as relatively easily deformable, which also applies to the upper edge regions of the upwardly directed flanges 7 and 8 of the profile girder. Thus, it is in these listed components that the deformations are principally to occur so that the profile girder 1 may possibly be released from the posts 2 in the event of a collision and gently retard the colliding vehicle without this running the risk of passing through the profile girder because of a breakage in it or in a joint between adjacent sections of it. The embodiment according to Figs. 4 and 5 does not differ from that described above in respect of the profile girder 1 and the posts 2. On the other hand, the connection members by means of which the profile girder 1 is secured to the posts 2 have a slightly different detailed design. In the embodiment according to Figs. 4 and 5, the support members 21 at a post 2 are mutually interconnected via a substantially horizontal intermediate section 26. The intermediate section extends horizontally out from a plate 27 which abuts against and is complementary to the web section 11 of the post 2. The plate is vertically adjustably secured in the post by means of a screw union 28 and a vertically extending and elongate opening 29 provided in the web 11. The catch members 22 at a post 2 are also mutually interconnected by the intermediary of a substantially horizontal clamping member 30 which, via a clamping element in the form of a screw union 31, may be brought into abutment against the intermediate section 26 in the vertical direction. Hereby, the catch members 22 and then support members 21 will between them clamp upper and lower engagement portions of the profile girder 1. In this embodiment, the connection members are, for the greater part, placed inside the circumscribed outer contour line of the profile girder 1. Figs. 6-8 show a further modified embodiment of the present invention. In this embodiment, the profile girder 1 is of a cross sectional configuration which is more reminiscent of a parallelogram or a rhomboid with gently rounded "corner portions". The surfaces between them are largely planar. Further, the projection of the profile girder laterally on both sides of the post 2 is greater than that which applies in the above-described embodiments, so that the profile girder, in this embodiment, is approx. 2-2.5 times wider than the post. Finally, the two upwardly directed flanges 7 and 8 are considerably longer than is the case in the above-described embodiments. The connection members for interconnecting the upper portions 4 of the posts 2 with the profile girder 1 include, also in this embodiment, support members 21 which abut against the outside of the profile girder immediately adjacent both edges 5 and 6 of the opening 3, i.e. in the regions of the lower edges of the flanges 7 and 8. As will be apparent from Fig. 6, the support members 21 have a bending angle between the shank facing towards the post 2 and the shank facing towards the underside of the profile girder 1, the bending angle being slightly more obtuse than the angle between the side surface 9 or 10 of the post and the underside of the profile girder adjacent the opening 3. This implies that, when the bolt 24 is tightened, the support member 21 will be bent to a slightly more acute angle, for which reason it will abut with a certain spring tension against the underside of the profile girder. This deformation of the support member 21 is also facilitated by the fact that it lacks the two flanges 25 which are illustrated in Fig. 2. For engagement interiorly in the profile girder 1, there is, in this embodiment, a counterpart to the above-described catch members 22. This counterpart has a rod 23 which is connected to the post 2 in the same manner as described above. In the upper end, the rod has, at opposing vertical edges, two angled, vertical portions 34 whose plane of extent is approximately at right angles to the plane of extent of the rod 23 and which have downwardly directed projections 35 whose lower end surfaces 36 abut against the inside of the profile girder 1 immediately at the opposing edges 5 and 6 of the opening 3, i.e. in the regions of the lower edges of the flanges 7 and 8. Between the downwardly directed projections 35 and the rod, there are downwardly directed accommodation spaces 37 in which the flanges 7 and 8 are located. In this embodiment, there is no engagement between the flanges 7 and 8 or their upper edges (see Fig. 6). In one variation of this embodiment, the accommodation spaces 37 are shallower so that engagement occurs between the upper edges of the flanges 7 and 8. Regardless of how the engagement with the profile girder 1 takes place, the angled portions 34 are constructed so as to give way in the event of a collision against the crash barrier. The lower ends of the rods 23 are connected to the post 2 and the support members 21 by means of bolts 24. The openings in the rods 23 through which the bolts 24 extend are open and are in communication with the periphery of the rods 23 by the intermediary of grooves 38 which, at their ends discharging in the bolt opening, are narrower than the diameter of the bolt 24 and which, in the event of a collision against the crash barrier, facilitate the release of the rods from the posts 2. Counterparts to the grooves 38 may also be employed in the embodiments according to Figs. 1-3. While the profile girder 1 has been shown as having an oval or possibly elliptical cross section, it is possible to design the profile girder with other cross sections, for example circular cross section, a recumbent rectangular cross section where the vertical, opposing side edges are gently arched while the upper side may be substantially planar. Further, the cross section of the profile girder is suitably symmetrical about a longitudinal centre vertical plane. Finally, it is also possible to design the profile girder 1 to be asymmetric in that the elongate opening is offset laterally in one direction so that the projection of the profile girder laterally outside the posts 2 will be greater in one direction. Such an embodiment is best suited for placing between a carriageway and the surrounding terrain.

Claims: WHAT IS CLAIMED IS: 1. A crash barrier comprising a number of posts (2) secured in the ground and a hollow profile girder (1) connected to them and having a longitudinal, downwardly directed opening (3), upper end portions (4) of the posts extending up thorough the opening to the interior of the profile girder and being connected thereto by means of connection members, characterised in that the connections between the posts and the profile girder are disposed to break within a collision area in the event of a collision against the crash barrier. 2. The crash barrier as claimed in Claim 1, characterised in that the profile girder (1) is of greater width in the horizontal direction than the posts (2); and that the projection of the profile girder laterally outside the posts (2) is substantially equal on both sides of the crash barrier. 3. The crash barrier as claimed in any of Claims 1 or 2, characterised in that the profile girder (1) is of a cross section with greater width in the horizontal direction than height in the vertical direction. 4. The crash barrier as claimed in any of Claims 1 to 3, characterised in that the profile girder (1) has a cross sectional configuration with gently rounded outer contour, such as an oval or ellipse-like outer contour. 5. The crash barrier as claimed in Claim 4, characterised in that the outer contour has a major axis which is substantially horizontal. 6. The crash barrier as claimed in any of Claims 1 to 5, characterised in that the longitudinal opening (3) of the profile girder (1) in the width direction is restricted by flanges (7, 8) which extend upwards from opposing side edges (5, 6) of the opening; and that connection members whose purpose is to interconnect a post (2) with the profile girder (1) are disposed to engage with upper and lower portions of the flanges. 7. The crash barrier as claimed in any of Claims 1 to 5, characterised in that the profile girder (1) has, on either side (5, 6) of the longitudinal opening (3), lower wall portions (33); and that connection members whose purpose is to interconnect a post (2) with the profile girder are disposed to engage with these lower wall portions. 8. The crash barrier as claimed in any of Claims 1 to 6, characterised in that the connection members, in relation to the dimensions of the profile girder, have slight dimensions for release of the profile girder from the posts (2) in the event of a collision. 9. The crash barrier as claimed in any of Claims 1 to 6 or 8, characterised in that at least one edge portion of the flanges (7, 8) is disposed to be deformed on collision against the crash barrier for release of the profile girder (1) from the posts (2). 10. The crash barrier as claimed in any of Claims 1 to 9, characterised in that the connection members include support members (21) which are connected to the posts (2) and which abut against the profile girder (1) in the region of the edge areas (5, 6) of the opening (3). 11. The crash barrier as claimed in any of Claims 6, 8 or 9, characterised in that the connection members include catch members (22) which are connected to the posts (2) and which engage with upper edge portions of the flanges (7, 8). 12. The crash barrier as claimed in Claim 11, characterised in that the catch members (22) are disposed at upper end portions of connection portions (23) which extend downwards between the flanges (7, 8) and adjacent side surfaces (9, 10) on the posts. 13. The crash barrier as claimed in Claims 10 and 11, characterised in that the support members (21) and the catch members (22) are connected to the posts by the intermediary of common anchorage members (24). 14. The crash barrier as claimed in Claim 13, characterised in that the support members (21) at a post (2) are interconnected to each other by the intermediary of a substantially horizontal intermediate section which is securable in the post; that the catch members (22) at a post are interconnected to each other by the intermediary of a substantially horizontal clamping portion; and that the clamping portion is clampable against the intermediate section by means of a clamping member. 15. The crash barrier as claimed in Claim 14, characterised in that the intermediate section is vertically adjustably secured in the post (2). 16. The crash barrier as claimed in any of Claims 1 to 5 and 7, characterised in that the connection members include catch members (22) which are interconnected with the posts (2) and which have abutment surfaces (32) which abut against the upper side of the lower wall portions (33). 17. The crash barrier as claimed in Claim 16, characterised in that the profile girder (1) on either side of the opening (3) has upwardly directed flanges (7, 8); and that the catch members (22) are disposed to straddle them. 18. The crash barrier as claimed in Claim 17, characterised in that the catch members (22) are disposed on connection portions which extend downwards between the flanges (7, 8) and adjacent side surfaces (9, 10) on the posts. 19. The crash barrier as claimed in Claims 10 and 16, characterised in that the catch members (22) and the support members (21) are connected to the post (2) by the intermediary of common anchorage members (24). 20. The crash barrier as claimed in Claim 11 or 16, characterised in that the catch members (22) have an opening through which an anchorage member (24) extends; and that the opening is connected to an edge portion of the catch member by the intermediary of a groove (38) or a recess of lesser width than the transverse dimension of the anchorage member. 21. The crash barrier as claimed in any of Claims 1 to 20, characterised in that a joint between two adjacent sections of the profile girder (1) is dimensioned for at least equally great tensile strength in the longitudinal direction of the profile girder as the portions of the profile girder located between the joints.

Inventors: WELANDSON ANDERS, WELANDSON, ANDERS
Applicants: VARMFOERZINKING AB, WELANDSON ANDERS, AB VARMFOERZINKING, WELANDSON, ANDERS
Application year: 2001
Main classification: E01F15
IPC codes: E01F15