The present invention relates to a pole arrangement according to the discription herein.
A lighting pole or other type of road pole installed next to a road is usually designed to be yielding in connection with a collision so that the pole may absorb the horizontally directed forces from a colliding motor vehicle by being deformed in a suitable manner. During its deformation, the yielding pole is intended to absorb the kinetic energy of the colliding motor vehicle so that the motor vehicle is slowed down in a comparatively gentle manner instead of being subjected to a sudden halt, whereby the risk of series personal injuries for the people travelling in the motor vehicle is reduced.
Yielding road poles are previously known in many different designs. Different types of previously known yielding road poles are for instance shown in U.S. Pat. No. 5,060,437 A and US 2010/0107521 A1.
The object of the present invention is to achieve a pole arrangement of the type mentioned by way of introduction with a new and favourable design.
According to the present invention, said object is achieved by a pole arrangement having the features hererin.
The pole arrangement according to the invention comprises:
When the above-mentioned pole is hit by a colliding motor vehicle, the tubular external wall will be buckled above the reinforcement element by the force from the motor vehicle, and parts of the tubular external wall will be pressed into some of the free spaces between the supporting projections of the wedge element. The design of the wedge element with supporting projections and intermediate free spaces on the side of the wedge element facing the tubular external wall of the pole will facilitate buckling of the part of the tubular wall located between the reinforcement element and the area hit by the motor vehicle. Thus, also the upper part of the section of the tubular external wall received in the cavity of the foundation will be buckled, which results in that the tubular external wall will be flattened and bend forwards in the direction of travel of the motor vehicle at the edge of the opening of the cavity. This deformation of the tubular external wall will contribute to a relatively gentle slowing down of the motor vehicle. The kinetic energy of the motor vehicle will also generate an axial pulling force on the section of the tubular external wall received in the cavity of the foundation, so that this section is displaced upwards in the cavity together with the reinforcement element. By its engagement with the tubular external wall, the wedge element will come loose from the cavity in connection with the upwardly directed displacement of said section of the tubular external wall, which will facilitate the further buckling of the tubular external wall. During said upwardly directed displacement, the reinforcement element will be slanted in the cavity of the foundation and cause a so-called drawer effect which slows down the displacement and prevents the pole from being torn loose from the foundation. Owing to the fact that the lower end of the pole is retained in the foundation, the pole may continue to contribute to an efficient slowing down of the motor vehicle during the entire deformation process. The wedge element and the reinforcement element will consequently co-operate in creating good opportunities for a relatively gentle but efficient slowing down of a motor vehicle in connection with a collision against the pole.
According to an embodiment of the invention, the reinforcement element has an axial length which is larger than or equal to 75% of the axial length of the section of the tubular external wall received in the cavity. With a length of the reinforcement element within this interval, a sufficiently efficient drawer effect is ensured at the same time as a bucklable area of sufficient length is left on the section of the tubular external wall received in the cavity of the foundation.
According to another embodiment of the invention, the reinforcement element is tubular. The reinforcement element can hereby be produced in a simple and efficient manner at the same time as the strength of the reinforcement element easily can be adapted by choosing a suitable material and wall thickness for the reinforcement element. Furthermore, it is relatively easy to mount a tubular reinforcement element to the tubular external wall of the pole.
According to an embodiment of the invention, the pole rests against a rest surface in the cavity through a lower end of the tubular external wall or a lower end of the reinforcement element.
According to another embodiment of the invention, the above-mentioned rest surface in the cavity of the foundation is conically tapered in the direction downwards. Hereby, it may in a simple manner be ensured that the pole is correctly mounted in the foundation with the lower end of the pole centered in the cavity of the foundation at the same time as it is ensured that the lower end of the tubular external wall or the lower end of the reinforcement element, already at the start of a deformation process, is in contact with and will slide upwards along an inner surface in the cavity under the influence of decelerating frictional forces.
According to another embodiment of the invention, a lower part of the reinforcement element projects below the lower end of the tubular external wall. It can hereby be ensured that the lower end of the pole during the deformation process will slide against the inner wall of the cavity of the foundation through the lower end of the reinforcement element instead of the lower end of the tubular external wall, whereby a big deformation of the lowest part of the tubular external wall, which in the worst case could result in a lost engagement between the tubular external wall and the reinforcement element, is avoided.
According to another embodiment of the invention, the tubular external wall has a polygonal cross-sectional shape with five or more sides, wherein at least three corners of the tubular external wall bear against a respective supporting projection of the wedge element and each one of the other corners of the tubular external wall extends through an intermediate free space between two supporting projections. The corners of the tubular external which do not bear against any supporting projection and instead extends through the intermediate free spaces between the supporting projections will form fold indications which facilitates for parts of the tubular external wall to be pressed into some of the free spaces between the supporting projections of the wedge element when the pole is hit by a motor vehicle, which contributes in facilitating the initial deformation of the tubular external wall in connection with a collision.
According to another embodiment of the invention, longitudinal slits are arranged in parallel with each other in the tubular external wall and distributed in the circumferential direction thereof in order to facilitate buckling of the tubular external wall in connection with a collision against the pole, wherein these slits are arranged in an area of the tubular external wall located above the foundation and where a colliding motor vehicle is expected to hit the tubular external wall. The buckling of the tubular external wall promoted by the slits at the area where the motor vehicle hits the pole will result in flattening and bending of the tubular external wall in this area. This deformation of the tubular external wall will contribute to a relatively gentle slowing down of the motor vehicle.
Other favourable features of the pole arrangement according to the invention will appear from the discription following below.
The invention will in the following be more closely described by means of embodiment examples, with reference to the appended drawings. It is shown in:
A pole arrangement 1 according to an embodiment of the present invention is illustrated in
The pole arrangement 1 further comprises a foundation 5 for anchoring the pole 2 to the ground, and a ring-shaped wedge element 6 for securing the pole in the foundation.
The foundation 5 is preferably made of concrete and has a vertical cavity 7 for receiving a lower section 8 of the tubular external wall 4 with the tubular external wall extending through an opening 9 at an upper end of the cavity 7. In the illustrated example, the cavity has an inner wall 10 with circular cross-sectional shape which is conically tapered in the direction downwards. At its lower end, the inner wall 10 is connected to a rest surface 11, which is conically tapered in the direction downwards and which has a bigger inclination than the inner wall 10. The foundation 5 is intended to be buried in the ground with the opening 9 of the cavity on a level with the ground surface.
The wedge element 6 extends around the tubular external wall 4 and is arranged at the upper end of the cavity 7 of the foundation at the opening 9 of the cavity. The wedge element 6 is clamped between the tubular external wall 4 and the inner wall 10 of the cavity 7 in order to secure the pole 2 in the cavity 7 by wedging. The wedge element 6 is on its inner side provided with supporting projections 14, through which the wedge element 6 bears against the tubular external wall 4. The supporting projections 14 are suitably three or more in number. The supporting projections 14 are arranged at a distance from each other as seen in the circumferential direction of the wedge element, wherein there are intermediate free spaces 15 between the supporting projections 14 as seen in the circumferential direction of the wedge element in order to allow parts of the tubular external wall 4 to be pressed into some of these free spaces 15 when the tubular external wall is buckled as a motor vehicle collides with the pole 2, as illustrated in
In the case when the tubular external wall 4 of the pole has a polygonal cross-sectional shape with an even number of sides 22, the wedge element 6 is suitably provided with half as many supporting projections 14 as the number of sides 22 of tubular external wall 4, wherein the wedge element 6 is mounted to the tubular external wall 4 in such a position that every second corner 21a of the tubular external wall 4 bears against a supporting projection 14 of the wedge element and each one of the other corners 21b of the tubular external wall 4 is arranged between two supporting projections 14, as illustrated in
The wedge element 6 is suitably made of plastic.
A reinforcement element 23 is mounted to a part of the section 8 of the tubular external wall 4 received in the cavity 7, below the wedge element 6, in order to counteract that this part is buckled when a motor vehicle collides with the pole 2. In the illustrated embodiment, said part constitutes the lower part of the section 8 of the tubular external wall 4 received in the cavity 7. An upper end 24 of the reinforcement element 23 is arranged at a distance from the above-mentioned opening 9 of the cavity 7 as seen in the axial direction, in order to allow buckling of the part of the tubular external wall 4 located between the upper end 24 of the reinforcement element and the opening 9 of the cavity when a motor vehicle collides with the pole 2. In the illustrated embodiment, the upper end 24 of the reinforcement element 23 is furthermore arranged at a distance from a lower edge 20 of the wedge element 6 as seen in the axial direction. The reinforcement element 23 is suitably dimensioned to bear as close as possible against the tubular external wall 4 and is fixed to the tubular external wall by means of suitable fastening members 25 or in another suitable manner, for instance by welding. The reinforcement element 23 is suitably tubular and has with advantage a circular cross-sectional shape, but could however as an alternative have a polygonal cross-sectional shape, for instance in correspondence with the polygonal cross-sectional shape of the tubular external wall 4, or a star-shaped cross-sectional shape. The reinforcement element 23 is preferably mounted inside the tubular external wall 4, but could as an alternative be mounted on the outside thereof.
In the illustrated embodiment, the reinforcement element 23 is mounted to the tubular external wall 4 in such a manner that a lower part 26 of the reinforcement element 23 projects below the lower end 27 of the tubular external wall 4, to thereby allow the pole 2 to rest against the above-mentioned rest surface 11 in the cavity 7 through the lower end 28 of the reinforcement element. However, the pole 2 could as an alternative rest against the support surface 11 through the lower end 27 of the tubular external wall 4.
The axial length L1 of the reinforcement element 23 is to be larger than or equal to the diameter of the above-mentioned opening 9 of the cavity 7 and smaller than or equal to 75% of the axial length L2 of the section 8 of the tubular external wall 4 received in the cavity 7. The axial length L1 of the reinforcement element 23 is suitably 40-60%, preferably about 50%, of the axial length L2 of the section 8 of the tubular external wall 4 received in the cavity 7.
The reinforcement element 23 is suitably made of steel.
The tubular external wall 4 is with advantage provided with longitudinal slits 30, which are arranged in parallel with each other in the tubular external wall 4 and distributed in the circumferential direction thereof in order to facilitate buckling of the tubular external wall 4 when a motor vehicle collides with the pole 2. The slits 30 are arranged in an area of the tubular external wall 4 which is located above the foundation 5 and where a colliding motor vehicle is expected to hit the tubular external wall 4. The slits 30 are suitably three or more in number.
The invention is of course not in any way limited to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a person skilled in the art without thereby deviating from the basic idea of the invention as defined in the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/SE2015/050647 | 6/3/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/190981 | 12/17/2015 | WO | A |
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20170121997 A1 | May 2017 | US |