[0001] The present invention relates to the sector of crash barriers of the so-called New
Jersey type and more specifically to the elements which, arranged as a continuation
of each other, form these barriers.
[0002] As is known, the main function of these barriers, and therefore the elements which
form them, is to absorb as gradually as possible the stresses produced by the impact
of a motor vehicle so as to keep it on the roadway, limiting the effects of the sudden
decelerations affecting the occupants of this motor vehicle as a result of its impact
against the barrier. The crash barrier elements designed hitherto essentially comprise
a support base fixed to the ground by means of anchoring bolts which pass through
it and the abovementioned cushioning effect is obtained by adjusting the tightening
torque of the said bolts and forming the aforementioned holes in the manner of an
eyelet so that, when an impact occurs, the element is able to slide over a given length
with respect to the bolts which brake its movement owing to the friction which is
generated between the underside of their fixing nut and the base of the said support
base of the element.
[0003] This approach, however, has drawbacks, the most important of which consists in the
objective difficulties which are encountered in obtaining the desired result.
[0004] It is sufficient in fact for the temperature and humidity conditions of the surrounding
environment to change or for the abovementioned tightness setting not to be sufficiently
precise in order to produce a substantial variation in the degree of the braking frictional
force described above, adversely affecting or modifying considerably the impact cushioning
effect which may vary considerably from that stipulated by the road safety regulations.
[0005] These regulations, as is known to persons skilled in the art, prescribe that a crash
barrier element subject to an impact equivalent to the application thereon of a force
of 9000 kg should move, sliding along the anchoring bolts, a distance of 10 cm.
[0006] Another drawback associated with the present-day constructional solutions described
above consists in the greater cost resulting from the necessary operation of tightening
the anchoring bolts by means of a torque spanner, which operation, moreover, sometimes
is somewhat awkward to perform.
[0007] The inventors of the subject of the present application have therefore provided an
innovative solution which eliminates all the drawbacks mentioned above, devising a
New Jersey motorway barrier element in which a compression-deformable member is arranged
transversely between each anchoring bolt and the said element, said member absorbing,
by means of deformation, the stresses of an impact of given magnitude and allowing,
with its deformation, a transverse displacement of the crash barrier over a predefined
length.
[0008] Obviously the holes formed in the base of the element must be eyelets oriented perpendicularly
with respect to the said element and having a sufficient longitudinal length to allow
the abovementioned displacement over a predefined length.
[0009] In a barrier element according to the invention it is in fact no longer necessary
to tighten the anchoring bolts with a predefined torque, but only by an amount sufficient
to obtain the stability of the element, without producing friction between said bolts
and the base and between the latter and the ground, as in the case of the elements
designed in accordance with the state of the art.
[0010] The subject of the present invention therefore relates to a New Jersey crash barrier
element as described in the accompanying Claim 1.
[0011] Two preferred examples of embodiment of the barrier element according to the invention
will now be described, with reference also to the accompanying drawings in which:
- Fig. 1 is a cross-sectional view of the first example of embodiment of a barrier element
used as a central reservation;
- Fig. 2 is the same cross-sectional view as Fig. 1 after the element has suffered a
knock due to the impact of a motor vehicle;
- Fig. 3 is a cross-sectional view of a second example of embodiment of a barrier element
used along one side of the roadway;
- Fig. 4 is an enlarged view of part of Fig. 3.
[0012] If we consider firstly Figure 1, this figure shows how, in an New Jersey barrier
element 1 according to the invention, the support base 2 is fixed to the ground T
by means of a plurality of anchoring bolts 3 (only one of which is visible in the
drawing) which are fixed to the ground T using known methods and each of which penetrates
inside said element upwards through an eyelet 5 oriented perpendicularly with respect
to the barrier element 1.
[0013] Between the surrounding casing 7 of the latter and each anchoring bolt 3 there are
arranged two members 4 which are compression-deformable, for example two metal plates
which are folded as shown in the drawing and which are arranged symmetrically as an
extension of each other in the transverse direction with respect to the element 1.
[0014] In the case shown, these two members 4 are integral with each other and form one
piece, but could also be two parts which are separate from each other.
[0015] The assembly of the two members 4 is passed through by the shank of the bolt 3 via
a complementary hole 6 formed therein.
[0016] When the barrier element 1 is subject to the thrust F (Fig. 2) resulting from the
impact of a motor vehicle, the surrounding casing 7 transmits to one of the two members
4 (that arranged on the left-hand side in the case in question) a force which compresses
it, deforming it firstly in a resilient manner and then in a permanent manner, causing
it to crumple and shortening it by a length L. During the course of this deformation,
the resilient member 4 absorbs and dissipates in a gradual manner the kinetic energy
of the motor vehicle which caused the impact, and the barrier element 1 is displaced
over a length L equal to the length of shortening of the member 4.
[0017] By suitably designing the members 4 both in terms of dimensions and in terms of type
of material, it is possible to achieve the result that the element 1, following a
thrust of given magnitude, is displaced over a given length L (for example, as already
mentioned, equal to 10 cm for a thrust F of 9000 kg).
[0018] Obviously, the barrier element 1, during deformation of one of the members 4, may
be displaced over the said length L since it slides with its base 2 relative to the
anchoring bolts 3 by means of the already mentioned eyelet 5. In connection with the
latter, it must be pointed out that, since a predefined friction between the base
2, bolts 3 and the ground T does not have to be produced, it may have a transverse
width slightly greater than the diameter of the shank of the said bolts 3, and this
play, which constitutes a further advantage of a barrier element according to the
invention, is able to compensate for any errors in position of the anchoring bolts,
facilitating and shortening the operations involved in installation of a crash barrier.
[0019] It must be pointed out that, in the case described hitherto, the surrounding casing
7 transmitted a compressive force to one of the members 4 by means of the projecting
locators 8, but various different embodiments are possible using locators of a different
type or kind, for example by forming them on the section which forms the said casing
or another part of the barrier element (these further possible embodiments are not
shown).
[0020] The example in Figs. 1 and 2 relates to a barrier element 1 with a symmetrical and
mirror-image form relative to its vertical centre plane, to be used as a central reservation
between two adjacent carriageways, but the barrier element of the invention may also
be used, changing only its shape, as a lateral guard-rail.
[0021] An example of a barrier element 11 of this type is shown in Figures 3 and 4.
[0022] In these figures it is possible to see how the aforementioned barrier element 11
also has, as in the previous example, a support base 12 for resting on the ground
T, provided with several eyelets 15 (one of which can be seen more clearly in Fig.
4) through each of which the shank of an anchoring bolt 3 penetrates, this bolt having
the function of fixing the barrier element 11 to the ground T. Between the surrounding
casing 17 of the element 11 and each bolt 3 there is also positioned in this case
a compression-deformable member 14 arranged transversely with respect to the element
11. This member 14, which is realized for example in the form of shaped and folded
metal plate as shown in the figures, performs the already described function of absorbing,
by means of deformation and a reduction in its length, the kinetic energy associated
with the impact of a motor vehicle against a crash barrier element, and, in a manner
entirely similar to that illustrated in the previous example, it allows the barrier
element 1 on which it is mounted to be displaced transversely, following an impact
of given magnitude, over a predefined length.
[0023] In this case also, advantageously, the metal plate forming the compression-deformable
member 14 has a hole which is passed through by the shank of the anchoring bolt 3,
the fixing nut 19 of which ensures the connection between the bolt 3 itself and the
said metallic plate.
[0024] It is pointed out how, in this case also, in order to transmit the force generated
by the impact of the casing 17, the member 14 is provided with an angle-piece 18 which
is fixed to the casing 17 in a suitable position, acts as a locating element and is
in contact with the deformable member, but other solutions are also possible.
[0025] All the observations made in respect of the previous example are also applicable,
without variation, to this second example of embodiment which, as in the case of the
embodiment described first, enables the predefined object of the inventors to be achieved,
namely that of providing a barrier element 1, 11 which, without the need for special
tightening of its anchoring bolts, absorbs a predefined energy resulting from the
impact of a motor vehicle, being displaced transversely over a length predefined during
the design stage.
1. New Jersey crash barrier element (1, 11), comprising a support base (2, 12) fixed
to the ground (T) by means of several anchoring bolts (3) which pass through holes
formed therein, characterized in that each of the said holes is an eyelet (5, 15) oriented in a direction perpendicular
to the element (1, 11) and between the latter and each anchoring bolt (3) there is
positioned transversely at least one compression-deformable member (4, 14) having
dimensions such that it is deformed, being shortened by a predefined length (L), when
the barrier element (1, 11) transmits to it a compressive force of predetermined intensity,
allowing the barrier element (1, 11) to be displaced in the direction of said compressive
force sliding over the said length (L) with respect to the anchoring bolt (3) along
said eyelet (5).
2. Barrier element (1) according to Claim 1, suitable for use as a central reservation,
in which two of the said compression-deformable members (4) are positioned transversely
between the element (1) and each anchoring bolt (3), integral or not with each other,
being arranged as an extension of each other and on opposite sides of the anchoring
bolt (3).
3. Barrier element according to one of the preceding claims, in which each of the said
compression-deformable members consists of a resilient member (4, 14) having a through-hole
(6, 16) inside which the shank of a anchoring bolt (3) is inserted in a complementary
manner.