FR2694028A1 - Road safety barrier assembly - comprises wooden rail made of half log with flat part vertical and reinforced by steel plate - Google Patents

Abstract

A wooden rail (1) is reinforced in the rear by steel reinforcing (2). The rail is made from a half log whose flat part is placed vertically, the reinforcing staying plated against this part. The steel reinforcement (2) covers the zone at the end of the rails and is fixed to them by bolts (3). A bolt (4) fixed to the two reinforcements (2) is covered by the support (5).A wooden separator serves to avoid contact of a vehicle wheel on the support in case of collision. The half log can be trapezoidal with an axis of symmetry whose large base is equal to the diameter of the circle circumscribing the trapezium. ADVANTAGE - Solves the problem of rupture of reinforcement and rail in event of collision.

Description

 BARIIIFJ7R Dr. SEWlRTTl! SMOOTH WOODEN ROUTTER WITH STEEL REINFORCEMENT, R USING HALF-ROUND I1 It is known to use wooden logs as a smooth for a safety barrier placed along roads.

However, these wooden logs have limited resistance to bending, this is why it is interesting to use a steel reinforcement placed at the rear of the log and developing over the entire length of the beam, to take up a large part of the tensile stresses of the boom subjected to the shock of a vehicle, as taught in French patent application No. 89 100 34.

 It appears that the impact behavior of such a device can pose a problem: in fact, the result of the force of the impact of the vehicle in the device is never perfectly horizontal, if only because the part of the bodywork coming into contact with the boom is rarely vertical; the forces due to the shock leading to a very significant setting in tension of the steel reinforcement, the wooden beam (of modulus of elasticity weak compared to that of steel) can turn on the side because of its inertia substantially equal by relation to a vertical plane and to a horizontal plane, when it is subjected to a resultant of non-horizontal forces. It is a known phenomenon that can be likened to a spill.

The result of the spill of the boom is that the steel reinforcement passes first below it, then in front of the boom; the two components of the device then become mechanically independent, and must therefore each withstand the forces of impact, whereas the device was designed so that they work in a combined manner, which will often lead to the rupture of the reinforcement and of the arm in wood.

The present invention provides a solution to this problem, by using a heald made in a half-log whose flat surface is placed vertically.

If the inertia of the beam in a vertical plane is much smaller than in a horizontal plane, the dumping is made very difficult, because the balance of the beam stretched in a horizontal arc during the impact will always be obtained with an orientation of the arm leading to the lowest inertia in a vertical plane.

 I1 is interesting to note that the section in dmi-circle with an inertia Jx in a horizontal plane equal to approximately 0.11 R exposing 4.9 being the radius of the circle, while its inertia Jy in a horizontal plane is worth approximately 0, 39 R exhibitor 4.

The inertia ratio therefore exceeds 3.5, whereas it is 1 for a log in a perfect circle.

A trapezoidal shape having an axis of symmetry and whose large base of the trapezoid is equal to the diameter of the circle (representing the log) circumscribed to the trapezium has the same property, namely an inertia ratio much greater than 1; this trapeze can
easily overlap in a half-log, thus leading to a shape which can be more effective on impact, due to the penetration of the edges of the trapezoidal section into the vehicle body, which leads to a very good quidage of this last.

Figure 1 illustrates the safety barrier, front view in elevation;
Figure 2 shows the same barrier, seen from the back
Figure 3 shows the same barrier, in section AA.

Figure 4 shows various trapezoidal sections that can be made in a half-log, and inscribed in its section.

FIG. 1 shows the safety device composed of a half-bolster 1, on which a steel reinforcement 2 is pressed, this reinforcement covering its two neighbors in the region of the end of the heddles so that they are secured together and with the smooth 1 by bolts 3, another bolt 4 secures the two reinforcements 2 with the support 5.

FIG. 2 represents the portion of the device seen from the rear, the overlapping of the reinforcements 2 is noted, as well as the nut of the bolt 4.

Figure 3 shows a section AA of Figure 2: it is understood that the force exerted on the heald 1 provided with its reinforcement 2, even if it is not perfectly horizontal, is not likely to modify the inclination of the section of the device, due to the ratio of the horizontal and vertical inertias of this section; we notice the presence of a wooden spacer 6, which plays a double rattle - avoid the contact of the vehicle wheel on the support in the case of - small shocks, less than 5 for example - give the visual illusion that the smooth is a complete log, if the thickness of the spacer is substantially equal to the radius of the log.

Figure 4 illustrates various trapezoidal sections that can be made from a half-log.

These forms also have great orientation stability at the time of impact due to the same reasons.

Claims (3)

1 - Road safety barrier composed of a wooden rail (1) reinforced at the rear by a steel reinforcement (2), characterized in that the rail is produced in a half-log whose flat part is placed vertically, the remaining reinforcement pressed against this part. 2 - road safety barrier according to claim 1 characterized in that the half log is cut in the shape of a trapezoid having an axis of symmetry, the large base of which is equal to the diameter of the circle circumscribed at the trapezoid, the circle representing the log of wood. 3 - Road safety barrier according to any one of the 2 first claims, characterized in that the steel reinforcements (2) are used in the region of the end of the beams, and are secured to them by the bolts (3) 4 - Road safety barrier according to any one of the first 3 claims, characterized in that a bolt (4) secures the two reinforcements (2) overlapping with the support (5).