EP0228334B2 - Motorway crash barriers - Google Patents

Description

The present invention relates to road safety barriers.

Road safety barriers or barriers are known which are placed at the edges of roads and motorways to restrain vehicles which accidentally leave the road.

The safety barriers have one or more horizontal rails placed on posts fixed to the ground.

Generally, the beams are metal profiles and they are supported by metal posts.

Wooden safety barriers are also known which include one or more wooden beams supported by wooden posts. Each stringer is formed of identical elements which are assembled end to end.

U.S. Patent 2,085,058 (WOOD) describes road safety rails or rails in which the beams include several wooden strips and cable loops which are engaged in grooves.

U.S. Patent 1,493,088 (VAN EPPS) describes road safety barriers with wooden rails placed on wooden poles. U.S. Patent 3,989,226 (BURGESS) describes beams composed of planks which are joined end to end by two metal plates profiled in a U shape and which are fixed on a post by a bolt.

Wooden slides are less expensive than metal slides and they fit better into the landscape. However, crash barriers must meet strength standards to be certified.

We know for this a wooden slide, as described in the publication of "LE BOIS NATIONAL" of September 14, 1985 pages 19 to 21 and which comprises at least one horizontal wooden beam which is composed of logs of constant diameters, which are supported by wooden poles and whose adjacent ends are assembled end to end by means of an assembly composed of a metal part, consisting of an elongated and flat rectangular plate, and placed in the horizontal plane passing through the axis of said logs, and straddling the junction between two logs, and located in the median plane vertical thereof, which metal part also has several holes through which are engaged bolts passing through one of said logs, and on each of which the nut is screwed.

Such wooden beams must withstand a determined tensile force which is for example 200 KN and more, the problem to be solved is to carry out an end-to-end assembly of the beams which does not risk catching a vehicle which slides the along a stringer and which resist the forces imposed by the regulations.

For this, the invention relates to safety barriers intended to be placed along the roads and which therefore comprise, in a known manner, some of the elements described above, but which specifically, to solve the problem of l invention, are such that said metal assembly between two logs comprises two parts making fishplates for each junction, and which are placed on either side of said logs; each additional log has a longitudinal groove which is situated on the side of the road and which has a width and a depth slightly greater than the width and the thickness of said metal plates and one of the two metal plates is housed at the inside said groove.

According to a preferred embodiment, each splint comprises, on its internal face, spikes each comprising a pair of plates located in planes perpendicular to the plane of said splint and each spike is associated with one of said holes and is located in major part of the same side of said hole as the longitudinal center of the splint, so that the two plates of each stud penetrate into the log wood when the splint is in place and tighten the fibers of the wood, which has the effect of '' prevent the edge from bursting when a tensile force is exerted on the boom.

The two plates of each pair form an angle between 0 ° and 120 ° between them.

Advantageously, the free edge of each plate is a sharp edge.

The invention results in new crash barriers for roads and highways.

The safety barriers according to the invention which are composed of wooden logs have the advantage of being inexpensive and of fitting into mountain landscapes or rustic environments more harmoniously than the usual metal slides.

The beams of logs of constant diameter according to the invention have the advantage that the vehicles which strike the slide easily slide along it until they stop or are returned to the road. , which reduces the severity of accidents.

The assemblies between heald elements according to the invention by means of two fishplates, one of which which is situated on the side of the road is housed in a groove, does not have any roughness projecting from the slide. These assemblies are inexpensive in terms of material and costs for wood preparation and installation.

The fishplates according to the invention provided on their internal face with plates parallel to the fibers of the wood or converging towards the through holes of the bolts, make it possible to effectively and relatively inexpensively prevent the wood from bursting under the action bolts when the slides are subjected to a significant tensile force.

Laboratory tests have shown that slides fitted with such pads can withstand tensile forces of 200 kilonewtons.

The slides according to the invention comprise posts and beams made of logs, preferably in logs of constant diameter, and the diameter of the posts is smaller than the diameter of the beams, so that in the event of impact, a certain number of posts break, absorbing the energy of the impact without the beam breaking. On the other hand, the heald elements which are well held together by the ribs, remain assembled together, so that one avoids the risk of accidents due to boom sections which come off and which enter the accident vehicle or which are thrown onto the road.

The stringer deforms elastically under the effect of the shock and it remains suspended from the posts that have remained in place on either side of the accident site at substantially the same height above the ground.

The slides according to the invention are easy to repair after an accident and repairs are inexpensive.

The following description refers to the appended drawings which represent, without any limiting nature, exemplary embodiments of road safety barriers according to the invention.

Figure 1 is a perspective view of a slide section according to the invention.

Figure 2 is a cross section along II-II of Figure 1.

Figure 3 is a rear view of the rear face of a first embodiment of a splint according to the invention.

Figure 4 is a perspective view of the rear face of a second embodiment of a splint according to the invention.

Figure 5 is an elevational view of one end of a slide according to the invention.

FIG. 6 is a view in elevation on a larger scale of the assembly of the inclined rail with the end of the horizontal rail of FIG. 5.

Figure 7 is a section along VII-VII of Figure 6.

Figure 8 is a horizontal sectional view of a slide element according to the invention placed in a curve.

Figures 1 and 2 show a section of a road safety barrier according to the invention. This slide comprises wooden posts 4 supporting a horizontal rail 3 which is composed of elements 3a assembled end to end. The posts 4 and the heald elements 3a are wooden logs.

The heald elements are wooden logs having a constant diameter, for example a diameter of 16, 18 or 20 cm and a length between 1.5 m and 4 m.

Preferably, the posts 4 are also wooden logs having a constant diameter of 12, 13 or 14 cm, which are therefore weaker than the heddle elements, so that in the event of an impact, they break first. absorbing part of the impact energy.

The height above ground of the posts 4 is of the order of 80 cm, so that the beams are placed at the regulatory height of 70 cm above the ground.

The wooden logs that make up the beams and posts are injected, that is, they are treated with wood preservatives such as creosote or other equivalent liquids that are injected into the wood.

The adjacent ends of two logs are assembled end to end by means of two splices 1a, 1b which are flat metal plates of elongated rectangular shape.

For example, the fishplates 1a, 1b are galvanized flat irons having a length of 500 to 1000 mm, a width of 60 to 80 mm and a thickness of 6 to 10 mm. Each fishplate is pierced with several holes 2, for example four holes which are symmetrical two by two with respect to the middle of the fishplate. The two fishplates 1a, 1b are placed on either side of the logs, in the horizontal plane passing through the axis of said logs and straddling the junction between two logs.

The two fishplates are fixed to each of the two logs by bolts 6 which each pass through the holes 2 of two fishplates located opposite one another and which pass through one of the logs and by a nut which is screwed on the part threaded bolt which is placed on the side opposite the road. The bolts 6 are for example round head bolts and square flange having a diameter of 16 mm.

Figures 1 and 2 show a preferred embodiment in which each log has a longitudinal groove 7, which is located on the side of the road, along the generatrix of the log closest to the road. The groove 7 has a width and a depth slightly greater than the width and the thickness of the metal plates 1a, 1b and the splint 1b located on the side of the road is housed entirely inside the groove 7, as well as the heads of the bolts 6 so that a vehicle which slides along the heald is not likely to catch on metal parts in relief relative to the heald.

Figure 1 shows an example in which the groove 7 extends over the entire length of the logs for ease of manufacture. Alternatively, each log may have two aligned grooves which are located at each end of the log and whose length is slightly greater than half the length of a splint.

FIG. 2 represents a cross section along II-II of FIG. 1 passing through the axis of a post 4.

The slide 3 is placed in front of the posts. In this example, one of the two ends of each log 3a is fixed to a post 4 by one of the bolts 6, which has a length sufficient to pass successively a splint 1b, a log 3a, a second splint 1a and the post 4.

An elastic washer 5 for taking up play is interposed between the rear splint 1a and a first nut 8b which is located between the post and the rear splint 1a.

A second nut 8a is screwed onto the rear end of the bolt 6 and bears against the post 4.

According to another variant shown in FIG. 8, the heddle is fixed to the posts 4 by bolts 22, the head of which is supported only on the rear splint 21b. In this case, the end of one of the logs has a housing for the head of the bolt 22.

When a car collides with a heald element, it exerts a significant force on it which is transmitted to the other elements via the fishplates and bolts.

Compression efforts are not dangerous because each log rests on the one that follows it and the wood resists compression well.

On the other hand, the tensile forces have the effect that the bolts engage between the fibers of the logs and burst them by an effect analogous to that of a wedge used to split wood.

During the tests, the beams must withstand determined tensile forces, for example tensile forces of 200 KN, and the problem to be solved is to make assemblies between logs which resist these tension forces without causing the logs to burst.

Figures 3 and 4 show the perspective views of the internal face of a splint 1, according to the invention, that is to say of the face applied against the wood.

This face comprises means which are associated with each hole 2 and which are intended to tighten the fibers of the wood to prevent the bolt which passes through the hole 2 from causing the wood to burst.

FIG. 3 represents an embodiment in which the splint 1 comprises studs which are each constituted by a pair of metal plates 9a, 9b and 10a, 10b which are situated in planes perpendicular to the plane of the plate 2.

Each stud is associated with a hole 2 and is placed in whole or in part on the side of the hole opposite the end of the nearest plate 1, that is to say between the holes 2 and the middle of the plate 1, that is to say the middle in the longitudinal direction. The two plates of each crampon converge towards each other towards the end of the nearest plate 1. The pads of each stud are symmetrical with respect to the longitudinal axis x x1 of the plate 1.

The angle α that the two plates of each stud form between them is between 0 ° and 120 °.

FIG. 3 represents an example in which the point of convergence of the two plates 9a, 9b or 10a, 10b of each stud is close to the hole 2 which they frame. As a variant, the studs 9a, 9b and 10a, 10b may be slightly offset longitudinally relative to the position shown in FIG. 3 but in all cases, most of the pads are located relative to a hole 2 on the middle side longitudinal of the plate 1.

It can be seen in FIG. 3 that the free edge 11 of the plates 9a, 9b and 10a, 10b is a cutting edge which is bevelled or sharpened, so that it easily penetrates into the wood when the splint 1 is in square.

By way of numerical example, without any limiting character, the plates 9a, 9b, 10a, 10b are flat irons having a length of 60 mm, a thickness of 2 to 6 mm and a height of 10 to 40 mm, which are welded on the back of each splice.

FIG. 4 represents an alternative embodiment in which the internal face of each splint 1 comprises four studs 12 each composed of a U-shaped profile section, the core of which is welded or screwed to the internal face of the plate 1 and the two wings of which extend perpendicularly thereto and parallel to the longitudinal axis x x1 of the plate 1.

FIG. 4 represents an example in which each stud is offset entirely towards the longitudinal middle of the plate 1 relative to the hole 2 with which it is associated.

Alternatively, each stud 12 can overlap the hole 2 and, in this case, the web of the profile is also drilled for the passage of the bolt.

The embodiment according to FIG. 4 corresponds to the embodiment according to FIG. 3 in the case where the angle α = 0 °.

The example according to FIG. 4 in which the two plates of each pair are part of the same piece, can be applied to the embodiment according to FIG. 3 and conversely if the two plates of each crampon are parallel as shown in the Figure 4, they can be independent of each other as shown in Figure 3.

Figures 5, 6 and 7 show a slide end according to the invention. The left part of the figures represents the end of the horizontal rail 3 which is extended to the right by an inclined rail 13 which joins the ground and which is inclined for example by 10 ° to the horizontal.

The rails 3 and 3a are made of injected wooden logs of constant diameter and are supported by posts 4.

FIGS. 6 and 7 show, on a larger scale, the junction between the juxtaposed ends of the horizontal rail 3 and the inclined rail 13.

We see in these figures that the assembly of the two juxtaposed logs is carried out by means of two elongated fishplates located on either side of the logs in the horizontal plane of the axis thereof.

Each fishplate is made up of two sections. Thus the fishplate 14 located on the side of the road is composed of two sections 14a and 14b which each have two holes 2 for the passage of the fixing bolts of the fishplates on one of the logs. One end 15 of the section 14a is folded twice, so that it is superimposed on the end of the section 14b.

Similarly, the splint 16 located on the side opposite the road is composed of two sections 16a and 16b and one end 17 of the section 16a is folded twice and is superimposed on the end of the section 16b.

The ends 15 and 17 as well as the ends of the sections 14b and 16b are pierced with a hole through which passes an assembly bolt 18 which is engaged in the empty space between the adjacent ends of the two logs due to the inclination of the log 13 and which passes through the post 4 situated at the junction between the end of the horizontal rail and the start of the inclined rail. A nut 19 is screwed onto the threaded end of the bolt 18, located at the rear of the post and it cooperates with a washer 20 pressed against the post 4.

Thus, the two sections of each splint are hinged together, which makes it possible to vary the angle of inclination of the inclined slide.

Dotted lines in FIGS. 6 and 7 have been shown spikes 12 according to FIG. 4, which are anchored in the wood to prevent it from bursting.

The sections 14a and 14b of the splint 14, located on the side of the road, are placed in a groove 7.

FIG. 8 represents a horizontal section passing through the axial horizontal plane of the logs of a section of slide according to the invention placed along a curve of the road. We see in this figure two adjacent logs 3a, 3b, which form an angle between them.

The adjacent ends of these two logs are assembled by two fishplates 21a, 21b, which are folded in the horizontal plane at an angle β, which is for example 6 °. As before, each fishplate has four holes for the passage of four bolts 6, which each pass through two fishplates and one of the logs. The splint 21a and the heads of the bolts located on the side of the road are housed in a groove 7.

To adapt the slide to curves of different radii, we vary the folding of the fishplates and the length of the logs. For example, if the radius of curvature of the road is less than 14 meters, logs with a length of 1.50 m are used and fishplates bent at 6 °. If the radius of curvature is between 14 m and 19 m, logs with a length of 2 m and fishplates bent at 6 ° are used. If the radius of curvature is between 19 m and 24 m, logs with a length of 2.50 m and fishplates bent at 6 ° are used. For radii of curvature between 24 m and 50 m, logs with a length of 2.50 m and a folding angle of 3 ° are used. For radii of curvature greater than 50 m, logs are used having a length of 2.50 m and a joint angle of the fishplates less than 3 °.

The above description represents safety barriers comprising a single beam. It is specified that this example is not limiting and that a slide according to the invention can comprise several horizontal rails of the same composition.

Claims (10)

1. Crash barrier for roads, of the type comprising at least one horizontal guard rail in wood (3), which is composed of round logs of woods of constant diameter (3a) each one having two ends, logs which are supported by wooden posts (4), and of which the adjacent ends are assembled end-to-end by assembling means composed of at least one metallic piece, constituted of an elongated and flat metallic plate, straddling the junction between two logs, which comprises a plurality of holes through which bolts (6) are engaged which bolts traverse one of said logs and on each one of which is screwed a nut, characterized in that said assembling means comprise two metal pieces forming fish-plates for each junction, and which are placed on either side of said logs, inside the horizontal plane traversing the axis of said logs, and each log (3) comprises a longitudinal groove (7) which is situated on the road side and which has a width and a depth slightly greater than the width and the thickness of said metallic plates and one of the two metallic plates (1b) is housed inside said groove (7).
2. Crash barrier according to claim 1, characterized in that each fish-plate comprises on its inner face, cramp-irons each one comprising a pair of strips (9a, 9b, 10a, 10b) situated in planes that are perpendicular to the plane of said fish-plate and each cramp-iron is associated with one of said holes (2) and is situated for the most part on the same side of said hole (2) as the longitudinal middle of the fish-plate, such that the two strips of each cramp-iron penetrates into the wood of the log when the fish-plate is in position and compresses the fibers of the wood, the effect of which is to prevent the wood from splitting when a pulling force is exerted on the rail.
3. Crash barrier according to claim 2, characterized in that the two strips of each cramp-iron form between them an angle (α) comprised between 0° and 120°.
4. Crash barrier according to any one of claims 2 and 3, characterized in that the free edge (11) of each strip is a cutting edge.
5. Crash barrier according to claim 3, characterized in that each cramp-iron is composed of two strips (9a, 9b or 10a, 10b) which converge towards each other and towards the nearest of said plates (1) and which are symmetrical with respect to the longitudinal axis (x x1) of said plate.
6. Crash barrier according to claim 3, characterized in that each cramp-iron is constituted by a U-section (12), of which the web is fixed to the back of the fish-plate and of which the sides are parallel to the longitudinal axis (x x1) of the fish-plate.
7. Crash barrier according to any one of claims 1 to 6, characterized in that the assembly means between two logs which constitute, one an end of a horizontal rail (3) and the other, the beginning of an inclined rail (13), comprises two fish-plates (14, 16) each one of which is constituted of two sections (14a, 14b and 16a, 16b) which are articulated on a bolt (18) which passes in the free space between the two logs and through a post (4) placed at the rear of the junction between the two logs.
8. Crash barrier according any one of claims 1 to 7, placed along a curve of the road, characterized in that it is composed of round logs (3a, 3b) of which the length varies with the radius of curvature of said curve and which are assembled by means of two fish-plates (21a, 21b) which are bent according to an angle (β) which varies with the radius of curvature of the curve.
9. Crash barrier according to any one of claims 1 to 8, characterized in that said rail is fixed to each one of said posts (4) by a nut (22) which traverses said post and of which the head bears against the fish-plate (21b) situated on the side opposite the road.
10. Crash barrier according to any one of claims 1 to 9, characterized in that the logs constituting the posts (4) have a constant diameter smaller than the diameter of the rail elements.

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