[0001] The present invention relates to a metal (safety) traffic barrier for roadways, of
the type known as "New Jersey barrier".
[0002] A New Jersey barrier is made up by a plurality of modules or modular members connected
to one another at their ends, each module having a profile facing the side of traffic,
comprising a series of sections being differently inclined with respect to a vertical
plane, so that the module width increases when going downwards from the top to the
base. The transverse vertical cross-section is substantially shaped as two superimposed
trapezia (double trapezium), namely an isosceles trapezium in a barrier located at
the middle of a roadway, or a rectangle trapezium in a side barrier, or a scalene
trapezium. Thanks to this shape the barrier acts onto the steering wheels of an impacting
vehicle so as to redirect it along its right travel direction preventing the vehicle
from invading the opposed roadway.
[0003] At the beginning New Jersey barriers were built of concrete. Subsequently, mainly
in view of an employment in situations where a light weight or the barrier is important,
metal barriers have been proposed, particularly of galvanised steel.
[0004] Examples of New Jersey steel barriers are disclosed in EP-A 0 428 097, EP-A 0 575
705, US-A 5 145 278 and WO-A 95/03453.
[0005] The modules of these metal barriers comprise upright members for anchoring the module
to the ground and a metal sheet section or mantle secured to the upright members and
made of a painted galvanised sheet, suitably folded to form the above discussed profile.
The metal sheet of the portions forming the profile is smooth.
[0006] The resistance of the barrier to the impacts of light vehicles is provided by the
thickness of the metal sheet, typically thicker than 2 millimetres, while the resistance
to the impacts of heavy vehicles is provided by longitudinal reinforcing members.
[0007] These known mantles exhibit some drawbacks.
[0008] A first drawback concerns the safety: actually, under certain conditions, the profile
concavity of a New Jersey metal barrier with a smooth surface can favour the overturning
of an impacting vehicle.
[0009] A second drawback is that the metal sheets requires a subsequent painting step after
the press forging step through which the desired profile is imparted to the metal
sheet. As a matter of fact, the existing machinery can only forge previously painted
sheets with a thickness lower than 2 millimetres whereas, as pointed out above, the
required mechanical resistance dictates the use of sheets thicker than 2 millimetres.
A separate painting step increases the manufacturing costs. Moreover the hue of the
painted modules may be not uniform, conferring to the barrier an apparently undulated
appearance that is both anaesthetic and annoying for the driver.
[0010] According to the invention there is provided a metal traffic barrier of the above
discussed type, wherein the mantle is realised so as to eliminate the risk of overturning
an impacting vehicle and to ensure a desired resistance even with a metal sheet of
reduced thickness, whereby an already painted metal sheet can be subjected to the
forming process, with consequent economic and aesthetical advantages.
[0011] According to the invention this object is achieved by providing a traffic barrier
module having at least one relief and at least one indentation in the barrier portion
disposed above the most inclined portion, said relief and indentation extending longitudinally
for the whole length of the module.
[0012] Preferably, the traffic barrier module provides for a plurality of said longitudinal
(lengthwise) relieves and said at least one indentation is defined by adjacent relieves.
[0013] For a better understanding of the invention reference is made to the attached drawings,
in which:
- Fig. 1 is a schematic perspective view of a traffic barrier according to the invention;
and
- Fig. 2 is a cross section view along line A-A of Fig. 1.
[0014] As illustrated in the drawings, a metal traffic barrier according to the invention,
indicated as a whole by reference 1, comprises a plurality of modules or modular members
2 connected to one another at their ends by hinge means, not shown in the Figure.
[0015] The modules 2 are made up by a panel surface or mantle 3 of galvanised and painted
metal sheet, and by a plurality of upright members 4, shown with dashed line in Fig.
1.
[0016] The mantle 3 is shaped in such a way that the cross section profile of a module,
as it is typical in these barriers, is substantially shaped as two superimposed trapezia
(isosceles trapezia in traffic barriers to be located along the road centre line as
a divider as the one shown in the Figure, or rectangle trapezia in case of side barriers)
with such a profile widening when moving downwards, and with a lower half portion
providing for a change of inclination that widens the barrier supporting base, adapted
to act onto the wheels of an impacting vehicle for redirecting it into its proper
travel direction. The mantle portion forming the inclined or oblique side of the upper
trapezium is indicated by 3a, whereas the portion forming the inclined side of the
lower trapezium is indicated by 3b. Openings or cuts 5 are formed in the portion 3b
for the passage of anchor means for securing the module to the road surface. Below
the portion 3b there is provided a substantially vertical portion 3c reaching the
ground and adapted to fit a road seat, if any.
[0017] Conventional longitudinal reinforcing members, schematically shown at 6, are associated
in a known manner to the mantle, for providing the barrier with the desired resistance
against the impacts of heavy vehicles.
[0018] According to the invention, at least the (shock-absorbing) upper portion 3a of the
surface of the mantle 3 has a fret pattern profile, with at least one longitudinal
relief 7 and at least one longitudinal indentation 8 extending for the whole length
of each module 2.
[0019] Preferably, there is provided a plurality of relieves 7, with each indentation 8
being defined between two of said relieves.
[0020] In the above illustrated conditions, the cross-section profiles of the relieves and
the indentations are equal. In the Figure a trapezoidal cross-section profile has
been represented, particularly that of an isosceles trapezium. Of course different
cross-section profiles are possible, e.g. rectangular, square, arcuated, triangular
profiles, and so on.
[0021] It is further possible to use profiles of the portion 3a in which the indentations
are formed in a central area of a zone defined between two relieves and are joined
to these latter by flat portions. In such cases the cross-section profiles of the
relieves can be different from those of the indentations.
[0022] The fret pattern or "Greek key" profile confers to the mantle an improved resistance
to collisions, whereby the mantle can be formed as a metal sheet thinner than that
conventionally used in metal barriers. For example, a sheet with a thickness of 1.8
millimetres can be employed.
[0023] This way not only the overall weight of each module is reduced, but a previously
painted galvanised plate or iron sheet can be used, thus eliminating the painting
step of the formed sheet. As pointed out above, this reduces the general manufacturing
costs and further allows to get modules with a uniform appearance, thus eliminating
the unpleasant and annoying "waving" effect, typical of traffic barriers assembled
with modules that have been painted after their shaping.
[0024] The presence of ribs, in addition to providing a reinforcement of the structure,
makes the barrier less prone to cause the overturn of the vehicles in case of collision.
[0025] Moreover, the indentations 8 can be used for example to accommodate cat's eyes and/or
other devices.
[0026] It is evident that the preceding description has been supplied as a mere and non-limiting
example of the invention and that modifications and changes are possible without departing
from the scope of the invention. Particularly, the barrier upper portion 3b could
be substantially vertical. Additionally, although Figure 1 shows a traffic barrier
to be used as a roadway divider, the invention can be applied in side barriers provided
with a single collision surface.
1. A metal traffic barrier for roadways, of the New Jersey type, comprising a plurality
of modules (2) each formed by a mantle (3) fixed to a plurality of upright members
(4) and having a profile comprising a plurality of portions (3a, 3b, 3c) having different
inclinations with respect to a vertical plane, the inclination being maximum in correspondence
of a portion (3b) in the lower half of the module (2), whereby the cross-section of
said module (2) widens from the top of the barrier (1) towards its base, characterized in that at least one portion (3a) of said profile, disposed above said portion of maximum
inclination (3b), provides for at least one relief (7) and at least one indentation
(8), both said relief and indentation longitudinally extending along the whole length
of the module (2).
2. A metal traffic barrier as claimed in claim 1, characterized in that said at least one portion (3b) comprises a plurality of parallel relieves (7).
3. A metal traffic barrier as claimed in claim 2, characterized in that said at least one indentation (8) is defined by adjacent longitudinal relieves (7).
4. A metal traffic barrier as claimed in any of the preceding claims, characterized in that said at least one relief (7) and said at least one indentation (8) have a transverse
cross-section selected from the group of trapezoidal, rectangular, triangular, circumferentially
arcuated or ellipsoidally arcuated.
5. A metal traffic barrier as claimed in any of the preceding claims, characterized in that it is formed by a metal sheet with a thickness smaller than 2 millimetres.
6. A metal traffic barrier as claimed in claim 5, characterized in that it is formed by a metal sheet painted in advance.