De Martino, Giovanni Battista (Via Raiola, 19 Castellammare di Stabbia, I-80053, IT)
Iacoangeli, Cesare (Ilva Pali Dalmine S.r.l. Via Terragneta, 90 Torre Annunziata, I-80058, IT)
Pernetti, Mariano (Ilva Pali Dalmine S.r.l. Via Terragneta, 90 Torre Annunziata, I-80058, IT)
De Martino, Giovanni Battista (Via Raiola, 19 Castellammare di Stabbia, I-80053, IT)
Iacoangeli, Cesare (Ilva Pali Dalmine S.r.l. Via Terragneta, 90 Torre Annunziata, I-80058, IT)
| 1. | 1) A semirigid, positioncorrectable, collision energydissipating guardrail comprising a number of posts (3), and at least one shaped rail (5) for sustaining collision by a vehicle; said shaped rail (5) being fitted to each of said posts (3) by a respective fastening assembly (6); each of said posts (3) being connected to a respective spacer arm (21,53) to which is fitted a bottom rail (19) extending parallel to said shaped rail (5); and the guardrail being characterized by said bottom rail (19) being located at such a height from ground level (49) as to be engaged by a supporting structure of a light vehicle. |
| 2. | A guardrail as claimed in Claim 1, characterized in that said supporting structure is defined by the usual front hood or by a fender for protecting a wheel of the vehicle. |
| 3. | A guardrail as claimed in Claim 1 or 2, characterized in that said bottom rail (19) has a top edge (34) located at a level slightly below the level of a bottom edge (12) of said shaped rail (5). |
| 4. | A guardrail as claimed in Claim 3, characterized in that said bottom rail (19) has a horizontal axis (23) located at a distance (L) of 400 to 600 mm from said ground level (49). |
| 5. | A guardrail as claimed in Claim 3 or 4, characterized in that said bottom rail (19) is set back vertically with respect to said shaped rail (5). |
| 6. | A guardrail as claimed in Claim 5, wherein said shaped rail (5) is defined by a section having three ridges separated by two grooves (4); characterized in that said bottom rail (19) is set back by a distance (D) of 10 to 50 mm with respect to a vertical plane (P) of said grooves (4); and in that the difference between the level of said bottom edge (12) of the shaped rail (5) and said top edge (34) of the bottom rail (19) ranges between 10 and 120 mm. |
| 7. | A guardrail as claimed in one of the foregoing Claims, characterized in that said bottom rail (19) comprises a vertical central wall (33), and a bottom wall (36) sloping towards said post (3). |
| 8. | A guardrail as claimed in Claims 3 and 7, characterized in that said top edge of said bottom rail (19) is defined by a horizontal top wall (34). |
| 9. | A guardrail as claimed in Claim 7 or 8, characterized in that said bottom wall (36) is slopped at an angle ranging between 20° and 30°. |
| 10. | A guardrail as claimed in one of Claims 7 to 9, characterized in that said spacer arm (21) is defined by a channel section having one end (41) shaped with a profile (42,43) complementary to the cross section of said bottom rail (19). |
| 11. | A guardrail as claimed in Claim 10, characterized in that said spacer arm (21) is connected to said bottom rail (19) by a connecting bracket (47). |
| 12. | A guardrail as claimed in Claim 11, characterized in that said bottom rail (19) is defined by segments (37) of a length corresponding to the distance between two of said posts (3); said bracket (47) being fitted by a bolt (48) to the ends of two contiguous segments (37) of said bottom rail (19). |
| 13. | A guardrail as claimed in Claim 12, characterized in that said slopped wall (36) of each of said segments (37) has two downwardlyopen recesses (38); each of said recesses (38) being engaged by said bolt (48) of the corresponding bracket (47). |
| 14. | A guardrail as claimed in one of Claims 9 to 13, characterized in that said spacer arm (21) is connected to the respective post (3) by a central bolt (30) and two lateral bolts (32); said central bolt (30) being located slightly above said lateral bolts (32). |
| 15. | A guardrail as claimed in Claim 14, characterized in that, at said lateral bolts (32), said spacer arm (21) has two horizontal slots (28) enabling a limited amount of rotation of said spacer arm (21) about said central bolt (30). |
| 16. | A guardrail as claimed in one of Claims 7 to 14, wherein each of said posts (3) comprises a double fastening assembly (6) connected to two opposite shaped rails (5); and a double spacer arm (53) connected to two opposite bottom rails (19); characterized in that said double spacer arm (53) has two symmetrically shaped ends (54) to receive said two bottom rails (19). |
BACKGROUND ART In known guardrails of the above type, a shaped rail, normally with three ridges, is fitted to a number of posts by respective fastening assemblies, which provide for dissipating the collision energy of a vehicle and for correcting the position of the rail to prevent the vehicle from going over the rail.
Known guardrails also comprise a wheel rail parallel to and below the shaped rail, and which is normally located about 300 mm off the ground to engage the wheel of a colliding light vehicle and so prevent the vehicle from nosing upwards.
In one known guardrail, the wheel rail is fitted directly to the posts and, being set back considerably
with respect to the shaped rail, is of only limited effectiveness by being engaged by the vehicle wheel after the vehicle collides with the shaped rail.
In another known guardrail, the wheel rail is fitted to each post by a spacer arm, so that the wheel rail and the shaped rail are substantially the same distance from the post; and the spacer arm is hinged to the post by a pin and a slot tapering in width so as to offer a certain resistance to the sliding movement of the pin during collision.
When struck by the wheels of an industrial vehicle capable of bending the spacer arms, this type of wheel rail tends to drop and therefore fails to prevent the vehicle from colliding with the post and jamming beneath the guardrail.
DISCLOSURE OF INVENTION It is an object of the present invention to provide a guardrail of the above type, in which the bottom rail contributes effectively towards absorbing the collision energy of the vehicle, and provides for eliminating the aforementioned drawbacks typically associated with known wheel rails.
According to the present invention, there is provided a semirigid, position-correctable, collision- energy-dissipating guardrail comprising a number of posts, and at least one shaped rail for sustaining collision by a vehicle; said shaped rail being fitted to
each of said posts by a respective fastening assembly ; each of said posts being connected to a respective spacer element to which is fitted a bottom rail extending parallel to said shaped rail, and is characterized by said bottom rail being located at such a height from ground level as to be engaged by a supporting structure of a light vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS Two preferred embodiments of the invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a cross section of a semirigid guardrail in accordance with a first embodiment of the invention; Figure 2 shows a view in perspective of a detail in Figure 1; Figure 3 shows a side view of an arm for supporting the bottom rail in Figure 1; Figure 4 shows a front view of the Figure 1 bottom rail; Figure 5 shows a cross section of a semirigid guardrail in accordance with a further embodiment of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in Figure 1 indicates as a whole a semirigid guardrail of the type installed along the edge of a road 2. Guardrail 1 comprises a number of posts 3
(only one shown in Figure 1); and a horizontal shaped rail 5. More specifically, shaped rail 5 is a known type comprising three ridges separated by two grooves 4, and is connected to a top portion 10 of each post 3 by a fastening assembly 6.
Each post 3 is defined by a metal channel section with the concavity facing one of the two adjacent posts 3; each channel section comprises two lateral walls 7 (Figure 2), and an intermediate wall 8 perpendicular to rail 5 ; each wall 7 terminates with a partial wall 8' parallel to wall 8 ; each post 3 is fitted vertically into the ground, at the side of road 2, by a bottom portion 9 (Figure 1); rail 5 comprises a top edge-11 and a bottom edge 12; and assembly 6 comprises a spacer 13 carried by post 3, an energy dissipator 14 located between rail 5 and spacer 13, and a body 16 connected telescopically to top portion 10 of post 3.
Spacer 13 provides for substantially rigid connection at the initial stage in the collision of a vehicle with rail 5, and for position adjustment, via rotation and translation of post 3 and spacer 13, at a subsequent collision stage. At the final collision stage, body 16 is released from post 3 to enable release of rail 5 from post 3, substantially as described in Italian Patent Application T094A000822 filed by CENTRO ACCIAI S. P. A.
Guardrail 1 also comprises a tie defined by a metal
strip 17 connected by a bracket 18 to the rear edge of each spacer 13; and a bottom rail 19, which is substituted for the usual wheel rail of known guardrails, extends parallel to and below shaped rail 5, and is fitted to a spacer arm 21 connected to post 3 as described later on.
According to the invention, arm 21 is defined by a channel section having a vertical central wall 22 with a horizontal axis 23, and two horizontal wings 24. Close to one end 26 (Figure 3) of central wall 22, central wall 22 comprises a circular hole 27 above axis 23; and two horizontal slots 28 along axis 23 and equidistant from hole 27.
Accordingly, wall 8 (Figure 1) of post 3 comprises a central hole 29 and two lateral holes 31 mating respectively with hole 27 and slots 28 in wall 22; and post 3 is connected to arm 21 by a central bolt 30 (Figure 2) in holes 27 and 29, and by two lateral bolts 32 in the two lateral holes 31 and two slots 28.
Bottom rail 19 is defined by a section having a vertical central wall 33, a horizontal top wall 34, and a subvertical bottom wall 36 sloping towards post 3 at an angle ranging between 20° and 30° and preferably of 25°. Bottom rail 19 is defined by segments 37 (Figure 4) of a length corresponding to the distance between two adjacent posts 3. More specifically, wall 36 of each segment 37 has two downwardly-open recesses 38 separated
by a distance equal to the center distance of two posts 3, so as to define two overlapping portions 39 between two contiguous segments 37.
A second end 41 (Figure 3) of wall 22 of each arm 21 has a profile complementary to the cross section of bottom rail 19 and comprising a vertical edge 42 and a sloping edge 43, which respectively engage wall 33 and wall 36 of rail 19. Close to end 41, wall 22 has a hole 44 on which one leg of an L-shaped bracket 47 is fitted by means of a bolt 46 (Figure 2).
The other leg of bracket 47 is located adjacent to sloping edge 43 of arm 21, and is connected by another bolt 48 to two contiguous segments 37 of bottom rail 19.
More specifically, bolt 48 engages a respective recess 38 of each of the two contiguous segments 37, so that each segment 37 may be assembled or removed by loosening bolts 48 of respective posts 3 and engaging or upwardly disengaging recesses 38 of segment 37.
As is known, the wheels of light vehicles such as cars and small vans have a radius of less than 300 mm, and are protected at the top by a portion of the supporting structure, which acts as a fender and, at the front, also as a hood supporting the bumper and respective light assembly. The supporting structure is therefore extremely resistant and, in the event of collision, possesses considerable energy which may be absorbed at least partly by rail 19 before the vehicle
body actually engages shaped rail 5.
Holes 29,31 in post 3 are advantageously so located as to position axis 23 of rail 19 at such a height L from ground level 49 as to enable rail 19 to be engaged by the supporting structure of the vehicle. In particular, top wall 34 of rail 19 is located slightly below bottom edge 12 of shaped rail 5, e. g. at a level 10 to 40 mm, and preferably about 20 mm, below the level of edge 12.
Post 3, in turn, is so sized that axis 23 of arm 21 is located at a distance L of 400 to 600 mm, and preferably 510 mm, from ground level 49; and arm 21 is of such a length as to set vertical wall 33 of rail 19 slightly back vertically with respect to shaped rail 5.
For example, distance D between wall 33 of rail 19 and the vertical plane P of grooves 4 of shaped rail 5 is 10 to 50 mm and preferably about 30 mm.
Guardrail 1 described operates as follows.
At the first stage in the collision of a car against guardrail 1, the front and lateral supporting structure of the car engages vertical wall 33 of bottom rail 19, which deforms and dissipates part of the kinetic energy of the car. At the next collision stage, the top of the car body engages shaped rail 5, while the bottom of the car body also engages sloping wall 36 of bottom rail 19.
At the first collision stage, therefore, engagement
of bottom rail 19 by the resisting structure of the car prevents the wheel from striking post 3; and, not being permitted to rotate with respect to post 3, bottom rail 19 makes no attempt to lessen the impact and so prevents the car from getting past.
In the event of collision involving an industrial vehicle with larger-diameter wheels, bottom rail 19 may also be engaged directly by the wheel, and shaped rail 5 struck by the supporting structure of the vehicle. In this case, by virtue of the diameter of bolts 30 and 32, the impact against bottom rail 19 eventually snaps bolts 30 and 32, so that bottom rail 19 ceases to resist the vehicle, and guardrail 1 shifts to a greater extent than when struck by a light vehicle.
In a further embodiment of the invention, the guardrail 51 (Figure 5) is a traffic-dividing type comprising two shaped rails 5 on either side of post 3, and two corresponding bottom rails 19; and fastening assembly 6 of post 3, in this case, comprises a double spacer 52 and two opposite dissipators 14 identical to those of guardrail 1.
The two bottom rails 19 are identical, and are connected to a double spacer arm 53, which is connected to post 3 by a central bolt 30 and two lateral bolts 32 in the same way as arm 21 in Figure 1, and comprises two symmetrically shaped ends 54 for connecting the two rails 19.
In this case, guardrail 51 is higher than in Figure 1; the distance L of axis 23 of arm 53 from ground level 49 may advantageously be 500 to 700 mm, and is preferably 540 mm; and the distance between the level of horizontal wall 34 of each bottom rail 19 and the level of bottom edge 12 of shaped rail 5 may be 60 to 120 mm, and is preferably about 90 mm.
When struck by a vehicle on either one of the two sides, guardrail 51 operates in the same way as already described for guardrail 1 in Figure 1.
As compared with known guardrails, the advantages of guardrail 1,51 featuring bottom rail 19 according to the invention will be clear from the foregoing description. In particular, bottom rail 19 is so located as to assist in absorbing the collision energy of a car, by being engaged first by a supporting structure, as opposed to the wheel, of the vehicle.
Clearly, changes may be made to guardrail 1,51 as described herein without, however, departing from the scope of the accompanying Claims. For example, slots 28 in arm 21 or 53 may be so located as to allow a certain amount of angular adjustment with respect to post 3.