Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
  • E01F15/00—Safety arrangements for slowing, redirecting or stopping errant vehicles, e.g. guard posts or bollards; Arrangements for reducing damage to roadside structures due to vehicular impact
  • E01F15/02—Continuous barriers extending along roads or between traffic lanes
  • E01F15/04—Continuous barriers extending along roads or between traffic lanes essentially made of longitudinal beams or rigid strips supported above ground at spaced points
  • E01F15/0407—Metal rails
  • E01F15/0438—Spacers between rails and posts, e.g. energy-absorbing means

Definitions

• the present invention relates to the field of safety barriers, which, generally consisting of a profiled rail mounted on vertical supports stuck in the ground, are arranged on either side of a road. These may be slides protecting a conventional road, a motorway, or, more particularly, a racing circuit. Generally, the rail of such a slide has a coated W section, and its vertical supports are U or C section profiles.
• the slides will restore part, absorbed by elastic deformation, of the kinetic energy of the impact, which, returning the vehicle to the roadway, puts the latter at risk of collision with another vehicle;
• the plastic deformation of the slide by which the rest of the impact energy is dissipated, generally results in a tilting of the vertical supports, which lie down, and in a depression of the rail by bending between two vertical supports.
• shock absorbing means to the slides, to, at least, limit the drawbacks which have just been mentioned.
• the present invention relates to a shock absorbing device, interposed between each vertical support and the rail, adapted to deform sufficiently to allow a sufficiently gentle damping of said shock, while not giving rise to a tilting or depression of the rail.
• a road safety barrier is provided provided with shock energy absorbing devices intervening between a slide rail and its vertical supports, each of said absorbing devices being characterized in that it comprises two arms which, starting from the vertical support, are arranged substantially in a V, in a horizontal plane, their free ends carrying the rail, said arms being adapted to open, under the effect of a constraint -
• FIG. 1 is a perspective view of a road safety barrier according to the present invention
• FIG. 2 is a sectional view, along the direction II-II of the slide of Figure 1
• Figure 3 is a sectional view, along the direction III-III of the slide of Figure 1;
• FIG. 4 and 5 are schematic views of the slide shown in the previous figures, showing its shape respectively before and after the application of a stress
• FIG. 6 and 7 are schematic views of a first alternative embodiment of a slide according to the present invention, showing its shape respectively before and after the application of a constraint
• FIGS. 8 and 9 are schematic views of a second alternative embodiment of a slide according to the present invention, showing its shape respectively before and after the application of a stress;
• FIG. 10 is a view showing the deformation of a slide according to the second alternative embodiment of the present invention, when a motor vehicle strikes it.
• Figures 1 to 5 show a first example of a road safety barrier according to the present invention.
• This slide comprises, in a known manner, a rail
• This rail is carried by vertical supports 2 inserted into the ground, here posts of rectangular section, as seen in FIG. 1.
• shock energy absorber comprising two arms 3A and 3B which, starting from the post 2, are arranged substantially in a V, in a horizontal plane, their free ends carrying the rail.
• the arms 3A and 3B are profiles of the same section as the slide rail, here a pair of coated W profiles arranged one above the other.
• these arms may have sections different from those of the rail 1, provided that they have good resistance to vertical stresses, so that they can only deform in the horizontal plane in which they are extend.
• Such a device 3 must be able to absorb most of the energy from the impact of a motor vehicle on the rail, so that the latter is not, at least, not bent by bending between two posts or tilted by post deformation 2.
• this energy absorption takes place by opening the arms 3A and 3B, so that the slide does not deforms only by bringing the rail 1 towards the posts 2.
• the arms 3A and 3B are constituted by the two ends of the same curved profile, at least part of the absorption of impact energy being by plastic deformation at the elbow of said profile.
• the initial opening angle of the arms 3A and 3B is of the order of 45 °.
• the withdrawal of the rail 1 towards the post 2 in this case, is substantially proportional, at least initially, to the variation in the opening angle of the arms.
• the resistance to deformation of the slide remains constant during the movement, and, consequently, the absorption of energy takes place regularly or gradually during the movement of opening of the arms.
• the fixing on a post 2 of the curved profile 3, forming an energy absorption device is done by means of bolts 10 passing through the bent part of said profile .
• the ends of the arms 3A and 3B are slidably mounted longitudinally along the rail 1.
• longitudinal slots 9 and 8 are formed on the flat central parts, respectively 20 and 21, of the rail 1 and of the arms 3A and 3B.
• Two slots 9 are provided, one above the other, on the free ends of the arms 3A and 3B, each of these slots being aligned with a slot 8 of the rail 1.
• Two hooking devices 11 are associated with each pair of aligned slots 8 and 9.
• Each of these devices comprises, as can be seen in FIGS. 2 and 3, a threaded rod 5 at the two ends of which bolts 6 are installed, said threaded rod passing through the slot of one of the parts of the sliding assembly as well as a bore of the other part formed in alignment with the own slot of the latter.
• one of the attachment devices 11 is integral with the rail 1 and slides in a slot 9 of the curved profile 3, while the other device 11 is integral with the end of the arm of the profile 3 in which is formed said slot 9, and slides in the corresponding slot 8 of rail 1.
• the hooking devices 11 are each in abutment against one end of the corresponding slot, the slot 9 extending, from the device 11 which passes through it, towards the post 2, while the slot 8 moves away, from the device 11 which passes through it, from this post 2.
• each of the arms 3A and 3B can therefore only slide on the rail 1 away from the post 2.
• the freedom of sliding of the arms relative to the rail is limited to the freedom that the arms 3A and 3B have of deviating from one another.
• the arms 3A and 3B actually carry the rail 1 while being able to move away from each other freely, without exerting any stress on the latter.
• the absorption of impact energy is effected, at least in part, by the interposition of friction or braking means between the parts mounted to slide relative to the 'other, that is to say, in the embodiment shown in Figures 1 to 5, the free ends of the arms 3A and 3B and the rail 1.
• this means of absorbing the impact energy is associated with that described above.
• This association is to be preferred because it presents a good efficiency / cost ratio, it facilitates the adjustment of the braking coefficient of the slide, and, finally, it makes it possible to best avoid any undesirable elastic deformation.
• Figures 2 and 3 show an example of arrangement implementing such a friction means between two sliding parts relative to each other.
• Friction plates 12 and 14 are fixed on, respectively, one and the other of the parts 1 and 3 of the sliding assembly, at the level of the respective flat central parts 21 and 20 of the latter, so as to be in contact with one another, between said parts 1 and 3 of the sliding assembly, as can be seen in FIG. 2.
• a pair of plates 12 and 14 is associated with each pair of aligned slots 8 and 9.
• the plates 12 and 14 of such a pair are aligned with the slots 8 and 9 corresponding, an end portion of the plate 12 lying opposite an end portion of the plate 14.
• slots 13 and 15 are provided in the plates, respectively, 12 and 14, in the extension of the slots, respectively, 8 and 9.
• the bolts 6 of the attachment devices 11, with which are associated elastic washers 16 with axial action, are tightened with a determined torque.
• the fastening devices 11 then play the role of means adapted to clamp one against the other, with an adjustable force, the two parts of the sliding assembly.
• the contact between the sliding parts 1 and 3 is made, in fact, by means of the plates 12 and 14, which will rub against each other during sliding. This friction dissipates a certain amount of impact energy into heat.
• the friction means 12 and 14 interposed between the two parts of the sliding assembly progressively brake the relative movement of these sliding parts.
• the plates 12 and 14 have a wedge shape, the thickness of each of them increasing as one moves away from the end facing the other room.
• the slope of the active surfaces of the plates 12 and 14 is, of course, chosen so as to compensate for the degressive braking effect, so that the energy absorption takes place regularly, or even gradually, during the movement of arms opening.
• the shapes of these plates 12 and 14 are chosen to be complementary, so that they extend one against the other throughout the movement.
• Figures 1 to 3 corresponds to the particular case of rails formed by the association of two coated W profiles arranged one above the other.
• the arms 103A and 103B are telescopic. Each of these arms therefore comprises two sliding parts relative to each other.
• the opening of the arms 103A and 103B is therefore possible, without modifying the interval separating the attachment points with the rail 101, by reducing the length of these arms, as can be seen in FIGS. 6 and 7.
• the ends of the arms 103A and 103B will be mounted on vertical axes integral with the rail 101, so that these arms can freely pivot in the horizontal plane in which they extend.
• friction means such as those described above may be interposed between the two sliding parts of each of the arms, in order to absorb, at least in part, the energy of the impact.
• Figures 8 and 9 show a second alternative embodiment of the present invention.
• This variant corresponds, in fact, to the variant of FIGS. 6 and 7, an additional absorbing device 213, comprising two additional arms 213A and 213B, being associated with the absorbing device 203.
• This alternative embodiment therefore avoids having to implement braking means with progressive effect such as those described in the first embodiment.
• said additional bra 213A, 213B being used only in tractio during the absorption of the impact energy, it is possible to replace each arm 213A, 213B by a cable associated with u equivalent braking means by means of friction 12, 14 of FIGS. 2 and 3.
• FIG. 10 shows, schematically, the deformation of a slide according to the second variant described, when a motor vehicle hits the rail 101 with a not too large angle of incidence.
• the rail 101 not being subject, strictly, to its vertical supports 102, can be deformed in a regular manner, without driving effect due to the reaction of the posts. It therefore bends, at the point of impact, so as to extend parallel to the direction of incident of the vehicle, then, as one moves away from the point of impact, returns gradually in a positio parallel to its initial position.
• this deformation of the rail is done by always approaching the posts 102, which allows the absorption of impact energy.
• the regular deformation of the rail 101 allows the vehicle to slide against it, making it possible to bring the latter back into the axis of the road.
• V-shaped arrangement of the arms of the shock energy absorption devices makes it possible to best combat the risk of longitudinal drive of the rail relative to its supports, when a vehicle, in particular a passenger car Formula 1 type sport, rolls against said rail.
• Another advantage provided by the present invention comes from the fact that only the shock energy absorption devices and, to a lesser extent, the rail, undergo deformations following an impact.
• the support posts are spared. This makes it much easier to replace the slides having suffered a significant shock.
• the impact energy absorption devices according to the invention which have just been described can be easily installed on the rails equipping, at present, the road network or the automobile circuits.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Vibration Dampers (AREA)
• Platform Screen Doors And Railroad Systems (AREA)
• Road Signs Or Road Markings (AREA)
• Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 1995
  • 1995-02-01 FR FR9501157A patent/FR2729980B1/fr not_active Expired - Fee Related
• 1996
  • 1996-02-01 EP EP96902326A patent/EP0807195B1/de not_active Expired - Lifetime
  • 1996-02-01 WO PCT/FR1996/000173 patent/WO1996023933A1/fr active IP Right Grant
  • 1996-02-01 ES ES96902326T patent/ES2130792T3/es not_active Expired - Lifetime
  • 1996-02-01 DE DE69602253T patent/DE69602253T2/de not_active Expired - Fee Related
  • 1996-02-01 AT AT96902326T patent/ATE179476T1/de active

Non-Patent Citations (1)

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