[0001] The present invention relates to variable geometry road barriers and methods for
manufacturing thereof.
[0002] Road barriers installed along the edges of roads protect vehicles from accidentally
exiting the road. The barriers are usually made of longitudinal beams installed on
posts.
[0003] A European patent
EP0677615 describes a variable configuration road barrier with energy dissipating means, which
comprises a post pivoted to a first base plate and a strut pivoted at one end to the
post and at the other end to a second base plate, wherein the post is pivoted to the
first base plate via a pivot pin movable in a slot provided with plastically deformable
energy dissipating means for narrowing the slot size to a size less than the diameter
of the pivot pin. Upon impact, the barrier changes its geometry such that the post
rotates with respect to the first base plate and moves along the slot, but its movement
is limited by the plastically deformable energy dissipating means. Therefore, the
energy is dissipated by plastically deforming the energy dissipating means at the
first base plate.
[0004] A US patent application
US20070007780 describes a kinetic energy absorber for connecting to a bumper of a car and comprising
a rotor connected with the bumper via a toothed bar and a multiplying gear. Upon impact
directed to the bumper, the translational motion of the bumper induces translational
motion of the toothed bar, which induces rotation of the rotor. The displacement vector
of the bumper is parallel to the displacement vector of the toothed bar.
[0005] The aim of the invention is to provide a variable geometry road barrier with alternative
energy dissipating means.
[0006] The object of the invention is a variable geometry road barrier comprising a plurality
of supports joined with at least one longitudinal beam, wherein at least one support
comprises a base, a substantially vertical tiltable post connected at its lower portion
with the base, a substantially horizontal toothed bar attached to the base and extending
substantially perpendicularly to the longitudinal beam, at least one arm connected
pivotably at its first end to an upper portion of the post, and at its second end
to an energy absorber, the energy absorber comprising at least one rotor coupled with
a toothed wheel mounted rotatably on a shaft to which the second end of the arm is
connected, the toothed wheel being meshed with the toothed bar such that the displacement
of the upper portion of the post induces rotation of the rotor.
[0007] The tiltable post can be made of a material deformable tiltably upon impact to the
upper portion of the post.
[0008] The tiltable post can be connected to the base via a tiltable joint.
[0009] The barrier may further comprise a limiter forming an extension of the toothed bar
and curved upwards.
[0010] The rotor can be a fly-wheel.
[0011] The arm may comprise a damper between its first and second end.
[0012] A pair of rotors can be mounted on the shaft at both sides of the toothed wheel.
[0013] The barrier may further comprise a pair of side toothed wheels mounted on the shaft
at both sides of the toothed wheel, a secondary shaft with a central rotor and a pair
of secondary toothed wheels mounted at both sides of the central rotor, at least one
arm coupling the primary shaft with the secondary shaft such that the secondary toothed
wheels are meshed with the side toothed wheels.
[0014] The barrier may further comprise at least one arm coupling the secondary shaft with
the upper portion of the post.
[0015] The pair of side toothed wheels may have a diameter or number of teeth larger than
that of the central toothed wheel.
[0016] The pair of secondary toothed wheels may have a diameter or number of teeth smaller
than that of the side toothed wheels.
[0017] The object of the invention is also a method for manufacturing of a variable geometry
road barrier comprising a plurality of supports joined with at least one longitudinal
beam, wherein at least one support comprises a base, a substantially vertical tiltable
post connected at its lower portion with the base, a substantially horizontal toothed
bar attached to the base and extending substantially perpendicularly to the longitudinal
beam, at least one arm connected pivotably at its first end to an upper portion of
the post, and at its second end to an energy absorber, the energy absorber comprising
at least one rotor coupled with a toothed wheel mounted rotatably on a shaft to which
the second end of the arm is connected, the toothed wheel being meshed with the toothed
bar such that the displacement of the upper portion of the post induces rotation of
the rotor, characterized in that it comprises the steps of forming and balancing of
the rotor, forming and hardening of the toothed bar, forming and hardening of the
toothed wheel and forming of the base, of the vertical tiltable post, of the arm and
assembling the elements to construct the variable geometry road barrier.
[0018] The invention is shown by means of an exemplary embodiments on a drawing, in which:
Fig. 1 shows the variable geometry road barrier according to the invention with a
support according to a first embodiment.
Fig. 2 shows the first embodiment of the support in an upright position.
Fig. 3 shows the first embodiment of the support in a tilted position.
Figs. 4 and 5 show a second embodiment of the support in an upright position.
Fig. 6 shows the second embodiment of the support in a tilted position.
Fig. 7 shows the process of manufacturing of the variable geometry road barrier according
to the invention.
[0019] Fig. 1 shows the variable geometry road barrier according to the invention with a
variable geometry road barrier support according to a first embodiment, wherein the
details of the first embodiment of the support are shown in Fig. 2, showing the support
in an upright position and Fig. 3, showing the support in a tilted position, caused
by an impact to the barrier. The road barrier comprises a plurality of road barrier
supports joined with longitudinal beams 160. Each support comprises a base 101 for
securing the support to the ground. A substantially vertical tiltable post 110 is
connected at its lower portion 111 with the base 101. The post 110 may be connected
to the base 101 directly in case the tiltable post 110 is made of deformable material,
such as an elastomer. Alternatively, the post 110 may be connected to the base 101
via a joint made of a deformable material, such as a deformable elastomer block or
a tiltable joint 113 in a form of a metal spring. A substantially horizontal toothed
bar 120 attached to the base 101 extends perpendicularly to the longitudinal beams
160, i.e. along the direction of predicted impact. The support further comprises an
energy absorber, comprising at least one rotor 131, 132, preferably in form of a flywheel,
mounted on a shaft 134, the shaft being coupled with a toothed wheel 133 via a one-way
clutch. Preferably, two rotors 131, 132 are mounted on the shaft 134, one at each
side of the toothed wheel 133. Preferably, the rotor 131, 132 has a form of a flywheel.
At least one arm 150, 155 is connected pivotably at its first end 151 with the upper
portion 112 of the post 110 and at its second end 152 pivotably with the shaft 134.
The toothed wheel 133 is meshed with the toothed bar 120 such that when the post 110
is tilted, as shown in Fig. 3, the displacement of the upper portion 112 of the post
110 causes, via the arm 150, 155, displacement of the toothed wheel 133 on the toothed
bar 120, thereby inducing rotation of the toothed wheel 133 and of the rotor 131,
132. Therefore, a part of the impact energy is accumulated in the rotor 131, 132.
The amount of energy accumulated in the rotor, in other words a rotatable mass, depends
on the weight of the rotor, its diameter and rotational speed, which in turn depends
on the length and the size of teeth of the toothed bar 120 and diameter of the toothed
wheel 133. Due to the fact that the arm 150 acts on the shaft 134 at an angle inclined
with respect to a horizontal direction, it causes both rotation of the toothed wheel
133 along the toothed bar 120, as well as presses the toothed wheel 133 to the toothed
bar 120 and limits the possibility of their un-meshing. By mounting the toothed wheel
133 on the shaft 134 via a one-way clutch, the shaft 134 and the rotors 131, 132 may
continue their rotation when the translation of the arm 150, 155 ends. A limiter 159
forming an extension of the toothed bar 120 in the direction of predicted impact and
curved upwards, is used to limit the displacement of the energy absorber in case of
impacts with energy higher than the energy limit absorbable on a given length of the
toothed bar 120. The arm 150, 155 may comprise a damper between its first 151 and
second 152 end to damp the movement of the second end 152 of the arm 150 at the first
phase of the impact, which facilitates start of rotation of the rotor 131, 132.
[0020] The variable geometry road barrier may also comprise supports according to the second
embodiment, as shown in Figs. 4 and 5 in an upright position and in Fig. 5 in a tilted
position. The support comprises a base 201, a post 210, a joint 213, a limiter 259
and a toothed bar 220 similar to the respective elements of the first embodiment.
Furthermore, the second embodiment comprises an energy absorber with enhanced energy
storage capacity as compared to the energy absorber of the first embodiment shown
in Figs. 1-3. A central toothed wheel 233 is mounted, via a one-way clutch, on a primary
shaft 234. A pair of side toothed wheels 235, 236, preferably having a larger pitch
diameter than the pitch diameter of the central toothed wheel 233, are mounted at
the sides of the central toothed wheel 233 so as to rotate along with the central
toothed wheel 233. A secondary shaft 237 carries a central rotor 231, preferably having
a form of a flywheel, and a pair of secondary toothed wheels 238, 239, preferably
having a diameter or number of teeth smaller than that of the side toothed wheels
(235, 236) mounted at the sides of the central rotor 231. The secondary shaft 237
is coupled with the primary shaft 234 via a pair of arms 240, 241 and with the upper
portion of the post 210 via a pair of arms 242, 243 such that the secondary toothed
wheels 238, 239 mesh with the side toothed wheels 235, 236. The primary shaft 234
is coupled with the upper portion 212 of the post 210 via a pair of side arms 250,
255, similarly as in case of the first embodiment. When the post 210 is tilted, as
shown in Fig. 5, the displacement of the upper portion 212 of the post 210 causes,
via the arms 250, 255, 242, 243, displacement of the toothed wheel 233 along the toothed
bar 220, thereby inducing rotation of the gearing 235, 236, 238, 239 and of the rotor
231. Therefore, a part of the impact energy is accumulated in the rotor 231. The energy
accumulator facilitates rotation of the rotor 231 to a higher speed than the rotor
131, 132 of the energy accumulator, wherein the speed depends on the gear ratio between
the toothed wheels 235, 236 and 238, 239, thereby accumulating higher energy.
[0021] Fig. 7 shows the process of manufacturing of the variable geometry road barrier according
to the invention. In steps 301-306 the elements of the energy absorber are formed,
including the rotor formed in step 301, the toothed bar formed in step 303 and the
toothed wheel(s) are formed in step 305. The elements of the energy absorber are manufactured
with high degree of precision, such as to allow efficient movement of the elements
with limited friction upon impact of forces of large magnitude. The rotor is balanced
in step 302 by precise profiling such that it can rotate with high rotational speeds.
The teeth of the toothed bar and toothed wheel(s) are hardened in steps 304, 306 such
as to withstand large forces and limit the friction between them. The other elements
of the road barrier are formed in step 307 and assembled with the energy absorber
in step 308. In order to provide high precision of manufacture of the energy absorber
and the other components of the road barrier of the invention, the following tools
can be used: a water jet cutter, a band saw, welding machines, a standard lathe, a
precision lathe, a standard miller, a precision miller, a surface grinder, an external
grinder, an internal grinder, a standard drill, a pillar drill, a hydraulic press,
a brake press, a bending machine for tubes and sections, a hydraulic bending machine,
a belt grinder, a fitter's vice, a compressor, an electro-erosion machine, a hobber,
a threader, a welder, cleaning tanks, measurement and control apparatus, a hardening
furnace, an electronic balancer, a marking-off table and marking-off tools.
[0022] The road barrier may comprise supports of the first and/or second embodiment, and
in addition it may be also supported by other, typical supports. The supports of the
first or second embodiment may be installed at places with high impact risk, such
as sharp turns, while typical supports may be installed at straight segments of the
road.
1. A variable geometry road barrier comprising a plurality of supports joined with at
least one longitudinal beam (160),
characterized in that at least one support comprises:
- a base (101, 201),
- a substantially vertical tiltable post (110, 210) connected at its lower portion
(111, 211) with the base (101, 201),
- a substantially horizontal toothed bar (120, 220) attached to the base (101, 201)
and extending substantially perpendicularly to the longitudinal beam (160),
- at least one arm (150, 155, 250, 255) connected pivotably at its first end (151,
251) to an upper portion (112, 212) of the post (110, 210), and at its second end
(152, 252) to an energy absorber,
- the energy absorber comprising at least one rotor (131, 132, 231) coupled with a
toothed wheel (133, 233) mounted rotatably on a shaft (134, 234) to which the second
end of the arm (150, 155, 250, 255) is connected, the toothed wheel (133, 233) being
meshed with the toothed bar (120, 220) such that the displacement of the upper portion
(112, 212) of the post (110, 210) induces rotation of the rotor (131, 132, 231).
2. The variable geometry road barrier according to claim 1, wherein the tiltable post
(110, 210) is made of a material deformable tiltably upon impact to the upper portion
(112, 212) of the post (110, 210).
3. The variable geometry road barrier according to any of previous claims, wherein the
tiltable post (110, 210) is connected to the base (101, 201) via a tiltable joint
(113, 213).
4. The variable geometry road barrier according to any of previous claims, further comprising
a limiter (159, 259) forming an extension of the toothed bar (120, 220) and curved
upwards.
5. The variable geometry road barrier according to any of previous claims, wherein the
rotor (131, 132, 231) is a fly-wheel.
6. The variable geometry road barrier according to any of previous claims, wherein the
arm (150, 155, 250, 255) comprises a damper between its first (151, 251) and second
(152, 252) end.
7. The variable geometry road barrier according to any of previous claims, wherein a
the toothed wheel (133, 233) is mounted rotatably on the shaft (134, 234) via a one-way
clutch.
8. The variable geometry road barrier according to any of previous claims, wherein a
pair of rotors (131, 132) are mounted on the shaft (134) at both sides of the toothed
wheel (133, 233).
8. The variable geometry road barrier according to any of previous claims, further comprising
- a pair of side toothed wheels (235, 236) mounted on the shaft (234) at both sides
of the toothed wheel (233),
- a secondary shaft (237) with a central rotor (231) and a pair of secondary toothed
wheels (238, 239) mounted at both sides of the central rotor (231),
- at least one arm (240, 241) coupling the primary shaft (234) with the secondary
shaft (237) such that the secondary toothed wheels (238, 239) are meshed with the
side toothed wheels (235, 236).
10. The variable geometry road barrier according to claim 9, further comprising at least
one arm (242, 243) coupling the secondary shaft (237) with the upper portion (212)
of the post (210).
11. The variable geometry road barrier according to any of claims 9-10, wherein the pair
of side toothed wheels (235, 236) has a larger pitch diameter than the pitch diameter
of the central toothed wheel (233).
12. The variable geometry road barrier according to any of claims 9-11, wherein the pair
of secondary toothed wheels (238, 239) have a smaller pitch diameter than the pitch
diameter of the side toothed wheels (235, 236).
13. A method for manufacturing of a variable geometry road barrier comprising a plurality
of supports joined with at least one longitudinal beam (160), wherein at least one
support comprises a base (101, 201), a substantially vertical tiltable post (110,
210) connected at its lower portion (111, 211) with the base (101, 201), a substantially
horizontal toothed bar (120, 220) attached to the base (101, 201) and extending substantially
perpendicularly to the longitudinal beam (160), at least one arm (150, 155, 250, 255)
connected pivotably at its first end (151, 251) to an upper portion (112, 212) of
the post (110, 210), and at its second end (152, 252) to an energy absorber, the energy
absorber comprising at least one rotor (131, 132, 231) coupled with a toothed wheel
(133, 233) mounted rotatably on a shaft (134, 234) to which the second end of the
arm (150, 155, 250, 255) is connected, the toothed wheel (133, 233) being meshed with
the toothed bar (120, 220) such that the displacement of the upper portion (112, 212)
of the post (110, 210) induces rotation of the rotor (131, 132, 231), characterized in that it comprises the steps of forming and balancing of the rotor (131, 132, 231), forming
and hardening of the toothed bar (120, 220), forming and hardening of the toothed
wheel (133, 233) and forming of the base (101, 201), of the vertical tiltable post
(110, 210), of the arm (150, 155, 250, 255) and assembling the elements to construct
the variable geometry road barrier.