NL2032450B1 - Energy-absorbing utility pole - Google Patents

Energy-absorbing utility pole Download PDF

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Publication number
NL2032450B1
NL2032450B1 NL2032450A NL2032450A NL2032450B1 NL 2032450 B1 NL2032450 B1 NL 2032450B1 NL 2032450 A NL2032450 A NL 2032450A NL 2032450 A NL2032450 A NL 2032450A NL 2032450 B1 NL2032450 B1 NL 2032450B1
Authority
NL
Netherlands
Prior art keywords
base
column
connection
pole
tube
Prior art date
Application number
NL2032450A
Other languages
Dutch (nl)
Inventor
Samuel Haakmat Johan
Rutgers Gerwin
Original Assignee
Nedal Aluminium B V
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nedal Aluminium B V filed Critical Nedal Aluminium B V
Priority to NL2032450A priority Critical patent/NL2032450B1/en
Priority to PCT/EP2023/069404 priority patent/WO2024013269A1/en
Application granted granted Critical
Publication of NL2032450B1 publication Critical patent/NL2032450B1/en

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
    • E01F9/00—Arrangement of road signs or traffic signals; Arrangements for enforcing caution
    • E01F9/60—Upright bodies, e.g. marker posts or bollards; Supports for road signs
    • E01F9/623—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection
    • E01F9/627—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection self-righting after deflection or displacement
    • E01F9/629—Traffic guidance, warning or control posts, bollards, pillars or like upstanding bodies or structures
    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
    • E01F9/00—Arrangement of road signs or traffic signals; Arrangements for enforcing caution
    • E01F9/60—Upright bodies, e.g. marker posts or bollards; Supports for road signs
    • E01F9/623—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection
    • E01F9/631—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection specially adapted for breaking, disengaging, collapsing or permanently deforming when deflected or displaced, e.g. by vehicle impact
    • E01F9/635—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection specially adapted for breaking, disengaging, collapsing or permanently deforming when deflected or displaced, e.g. by vehicle impact by shearing or tearing, e.g. having weakened zones
    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
    • E01F9/00—Arrangement of road signs or traffic signals; Arrangements for enforcing caution
    • E01F9/60—Upright bodies, e.g. marker posts or bollards; Supports for road signs
    • E01F9/623—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection
    • E01F9/631—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection specially adapted for breaking, disengaging, collapsing or permanently deforming when deflected or displaced, e.g. by vehicle impact
    • E01F9/638—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection specially adapted for breaking, disengaging, collapsing or permanently deforming when deflected or displaced, e.g. by vehicle impact by connection of stud-and-socket type, e.g. spring-loaded

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)

Abstract

The present invention relates to an energy-absorbing utility pole for absorbing kinetic energy of a vehicle colliding with the utility pole, the utility pole comprising: 5 - a pole base, comprising a hollow base tube configured to be inserted in the ground for securing the utility pole with respect to the ground, - a hollow tubular column, connected to the base and extending away from the base, - a tensile element, located in the base and the column, wherein the tensile element is connected to the base at a base connection and to the 10 column at a column connection, wherein the tensile element has a length larger than a connection distance between the base connection and the column connection, and wherein the difference between the length of the tensile element and the connection distance provides an excess length of the tensile element to provide a time delay for tightening the tensile element upon collision of the vehicle into the utility pole, 15 characterized in that the excess length of the tensile element is accommodated in between the base connection and the column connection.

Description

P35674NLOO/TRE
Title: Energy-absorbing utility pole
Field of the invention
The present invention relates to an energy-absorbing utility pole, for example a traffic light pole, a street lighting pole, a vehicle charging station and/or a traffic sign support, for absorbing kinetic energy of a vehicle colliding with the utility pole. The present invention further provides a method of installing a utility pole.
State of the art
At present, various types of utility poles are known, such as traffic light poles, street lighting poles, traffic sign supports, a vehicle charging station, or utility poles that have a combination of these functionalities. Utility poles generally comprise a base portion that is inserted in the ground for securing the utility pole with respect to the ground and a column portion, which may be attached to the base portion by means of a rigid bolted connection, a press-fit connection, or bonding connection or which may be integrally connected to the base portion to form a unitary utility pole. Utility poles are typically installed next to roads and may therefore be subject to vehicles that accidently collide with these poles. Conventionally, these poles are relatively stiff and rigid, which implies that vehicles abruptly come to a stop upon colliding with the pole. This may effect a relatively large amount of damage to the vehicle and may give rise to severe injuries for its passengers.
To reduce the risk of injuries resulting from such collisions, several types of collision-safe utility poles are known that reduce the impacts of collisions. A first type of a collision-safe utility pole comprises a base and a separate column that is connected to the base by means of coupling assembly. An example of such a coupling assembly is disclosed in European Patent
EP 3 081 695 B1, being configured to firmly interconnect the base and the column during normal operation of the utility pole and configured to shear off during a collision, in order to uncouple the column from the base and to prevent the pole from abruptly stopping the vehicle.
This first type of collision-safe utility pole may have the drawback that the vehicle's velocity is not reduced significantly. This may give the result that the vehicle may move further after colliding with the pole, virtually not being decelerated, possibly towards other roadside objects that are less resilient, such a trees or buildings, that abruptly stop the vehicle after all.
A second type of a collision-safe utility pole is disclosed in European patent EP 2 735 652
B1, which discloses a cable that forms a connection between a lower part and an upper part of the pole. The cable has an excess length that allows the lower part and the upper part to be held together after a vehicle has collided into the pole. As a result, the cable is able to absorb kinetic energy of the vehicle, reducing the velocity of the vehicle.
This second type of collision-safe utility pole is able to both absorb kinetic energy of the vehicle both during impact, upon breakage of the pole, and later, when the cable is tensioned.
However, the excess length of the cable is accommodated in an upper part of the pole, above a column connection thereof. This has the drawback that, during tensioning of the cable, the excess length has to pass between the column wall and the column connection, where the cable may end up being entangled. The entanglements may reduce the effectivity of the cable, possibly resulting in less kinetic energy to be absorbed.
Object of the invention
It is therefore an object of the invention to overcome the above-mentioned drawbacks, or at least to provide an alternative utility pole.
Detailed description
The present invention provides, according to a first aspect, an energy-absorbing utility pole, for example a traffic light pole, a street lighting pole, a vehicle charging station and/or a traffic sign support, for absorbing kinetic energy of a vehicle colliding with the utility pole, the utility pole comprising: - a pole base, configured to be inserted in the ground for securing the utility pole with respect to the ground, - a hollow tubular column, connected to the base and extending away from the base in a longitudinal direction of the pole, - a tensile element, located in the base and the column, wherein the tensile element is connected to the base at a base connection and to the column at a column connection, wherein the tensile element has a length larger than a connection distance between the base connection and the column connection, and wherein the difference between the length of the tensile element and the connection distance provides an excess length of the tensile element to provide a time delay for tightening the tensile element upon collision of the vehicle into the utility pole, characterized in that the excess length of the tensile element is accommodated in between the base connection and the column connection, and wherein at least part of the tensile element is folded parallel to the longitudinal direction to accommodate the excess length in between the base connection and the column connection.
The present utility pole is able to absorb kinetic energy of a vehicle, by reducing the velocity of the vehicle from a relatively high impact velocity to a relatively low exit velocity. The exit velocity may be defined by means of the so-called Theoretical Head Impact Velocity (THIV-
value). Utility poles can be classified into several categories of energy absorption, depending on the established THIV-value that is assigned after performing certain standardized tests.
Such tests typically consists of a test vehicle colliding with the pole, typically with a velocity of 100 km/h. At a certain point in the vehicle’s trajectory from the pole, typically after 12 meters, the vehicles exit velocity is measured which represents the THIV-value according to European norm EN 12767. Examples of certain exit velocity values that are defined as THIV-values are 100 km/h, 70 km/h and 50 km/h, as defined in EN12767. The present invention may provide for a utility pole in the high-energy category of energy absorption, offering the largest possible amount of kinetic energy absorbed. THIV-values of 100 km/h, 70 km/h and 50 km/h are all examples of high-energy absorbing categories.
The utility pole may serve various purposes along the roadside, for example to support a traffic sign, as a vehicle charging station or as a street lighting pole. Generally, the pole comprises the base and the column, which may be provided as separate components or as a single unitary component. In any case, the pole base is arranged in the ground at least partially in an installed configuration of the pole. The base may be fully arranged in the ground or may be arranged in the ground partially, protruding partially out of the ground, thereby crossing the ground level. The base is configured to form a foundation for the pole, to hold the pole substantially upright in the installed configuration, i.e. during normal use. Also during impact of a vehicle colliding with the pole, the base is configured to remain in place, in order to form an anchor for decelerating the vehicle. To this effect, the base may be embodied as a tube inserted in the ground. Alternatively, however, the base may comprise a another foundation, such as a concrete block, and/or the base may from part of a road structure, such as a viaduct or the like.
The column is connected to the base, e.g. either integrally or by means of a dedicated coupling assembly, and forms the support for the traffic sign, the streetlighting armature or the like. To this effect, the column extends aways from the base in a vertically upward direction.
Along this upward direction, a longitudinal direction of the pole can be defined, which may be substantially vertical as well. The column may be arranged above the ground level completely, but may alternatively protrude into the ground.
The base and/or the column may be made of a metallic material, for example made of aluminium. Metallic materials have the benefit of being strong and durable. Especially aluminium is also lightweight and can be extruded for manufacturing the pole. Alternatively, the base and/or the column may be made at least partially of a different material, such as a plastic material and/or a composite material.
Inside the base and the hollow column, the tensile element is arranged, which forms an additional connection between the column and the base. The tensile element is connected to the base at a base connection, for example a base connection located below the ground level.
The base connection may be formed by a transverse rod through the base, e.g. extending through the base in a transverse direction perpendicular to the longitudinal direction. The tensile element is further connected to the column at a column connection, for example a column connection located above the ground level. The column connection may also be formed by a transverse rod through the hollow column, e.g. extending through the hollow column in the transverse direction.
The base may be partially and/or completely hollow. The tensile element may be arranged inside the hollow base. This way, the tensile element may be protected.
The base connection and the column connection of the pole, e.g. both transverse rods, are spaced apart over the connection distance, which may be defined as the shortest distance between the base connection and the column connection in the installed configuration of the pole, i.e. parallel to the longitudinal direction. The length of the tensile element is larger than the connection distance, which implies that an excess length of the tensile element is defined as the difference between the length of the tensile element and the connection distance.
In case a vehicle collides with the pole, the pole may deform and rupture as a result of the impact. The deformation and rupture may reduce the velocity of the vehicle due to absorption of kinetic energy of the vehicle, but it is not desired to fully stop the vehicle upon impact directly, as that would stop the vehicle too abruptly. After rupture of the pole, the column may be taken along with the vehicle and may be separated from the base, which remains in the ground. This may have the effect that the distance between the base connection and the pole connection becomes larger.
As a result, the tensile element will be tensioned when the distance between the base connection and the pole connection becomes equal to the length of the tensile element. When the tensile element is tensioned, a second mode of energy absorption may be initiated by the pole, since the column will get to deform in front of the vehicle. This deformation will absorb additional kinetic energy, thereby further reducing the velocity of the vehicle. However, the tensioning of the tensile element will be delayed relative to the moment of rupture as a result of the excess length of the tensile element.
The present invention differs from the known energy-absorbing utility poles in that the excess length of the tensile element is accommodated in between the base connection and the column connection. This may offer a benefit for the present invention, since the excess length of the tensile element does not need to pass a tight space between the column wall and the column connection and/or the base wall and the base connection. This reduces the risk of the tensile element getting stuck or entangling when the pole is ruptured, which would influence the absorption of kinetic energy after collision and especially the moment at which the second mode of kinetic energy is absorbed.
To further improve the tensioning of the tensile element, at least part of the tensile element is folded parallel to the longitudinal direction. The folded part may reduce the shortest length between the base connection and the column connection, so that the excess length in between the base connection and the column connection is accommodated by the folded part.
The folded part of the tensile element may extend parallel to the longitudinal direction back and forth, i.e. extending alternately upward and downward, in between folds.
With the folded part, the excess length of the tensioning element may be arranged in a structured manner, improving the tensioning when the tensile element is unfolded.
Furthermore, with the folded part extending in the longitudinal direction, the unfolding of the tensile element may be improved, since the unfolding takes places in a direction parallel to the hollow interior in the column.
In an embodiment, the folded part of the tensile element comprises an even number of folds, for example two, four or six folds. The even number of folds may provide that, at the folded part, the direction of the tensile element is reversed an even number of times. Seen from the column connection, the tensile element may extend downwards to a first fold, where the tensile element is folded upwards towards a second fold, where the tensile element is folded downward, towards the base connection.
When a further even number of folds were to be provided, the accommodated excess length can be increased. Alternatively or additionally, the length of the folded part of the tensile element may be reduced, whilst still being able to accommodate the same excess length.
In an embodiment, the folded part of the tensile element is located at a lower end of the tensile element. According to this embodiment, the folded part may be located close to the base connection, inside the pole base, optionally being located in the pole base entirely. This may further improve the tensioning of the tensile element after the collision, since the column is taken along with the vehicle, whereas the folded part may remain close to, or even inside the base, not being taken along, but solely being unfolded.
Alternatively, however, the folded part of the tensile element may be located at an upper end of the tensile element, i.e. close to the column connection and inside the column.
According to a further embodiment, the tensile element may comprise more than a single folded part. For example, the tensile element may comprise a first folded part at its lower end and a second folded part at its upper end. The multiple folded parts may further improve the unfolding of the tensile element and/or may further increase the excess length that can be accommodated.
In an embodiment, the folded part of the tensile element crosses the ground level in an installed configuration of the pole. This may provide that the folded part is present at the location where the pole typically ruptures after impact of the vehicle, typically at the ground level. As such, the folded part may obtain more space to unfold, which may further improve the absorption of kinetic energy.
In an embodiment, the folded part of the tensile element is bundled, for example by means of elastic bands. The alternating upward and downward lengths of the folded part of the tensile element are preferably held together to prevent them from getting entangled, which would otherwise disadvantageously effect the unfolding. By bundling the folded parts, the upward and downward lengths are held against each other in an orderly manner.
The bundling may be carried out with one or more additional elements that encircle all upward and downward lengths of the folded part to hold them together. This may for example be done by means of elastic bands ar by means of adhesive tape, configured to rupture when the tensile element is unfolded after impact.
In an embodiment, the connection distance is between 30% and 60%, preferably between 40% and 50%, for example about 45% of the length of the tensile element in the longitudinal direction. With the connection distance being in between 30% and 60% of the length of the tensile element, the excess length of the tensile element is respectively 70% to 40% of the length of the tensile element. It was found that a ratio in this range between the length of the tensile element and the excess length is beneficial in obtaining the desired absorption of kinetic energy from the vehicle, irrespective of the height of the pole.
As an example, the column may have an overall height of about 12 meters above the ground level and the pole base may be inserted in the ground about 2 meters. The base connection may be provided at a bottom end of the pole base and the column connection may be provided at a height of about 2 meters above the ground level, such as 2,3 meters. The connection distance, in between the base connection and the column connection, is thereby about 4 meters. In this embodiment, the tensile element may have a length of 10 meters, which implies that the excess length is 8 meters. The folded part may comprise 4 folds, which implies that each one of the upward and downward lengths of the folded part, i.e. 5 in total, may have an individual length of about 1.5 meters. Accordingly, the height of the folded part is about 1.5 meters as well.
Should the folded part, however, comprise 2 folds, there would be 3 upward and downward lengths and the folded part would have a height of about 3 meters.
However, other dimensions may be used as well.
The connection distance may depend on the type and the length of utility pole. Optionally, the length of the tensile element and/or the connection distance may be the same for each utility pole, irrespectively of the overall height of the utility pole.
In an embodiment, the tensile element comprises at least one strap element, each comprising a first loop surrounding the column connection and an opposed second loop surrounding the base connection. The tensile element may thereby be formed by a single strap element, but, alternatively, the tensile element may be formed by two or more strap elements.
The first loop and/or the second loop may surround a rod inserted therethrough.
Additionally or alternatively, an opening may be provided in the at least one strap element, for example an eye, through which a rod is inserted.
The two or more strap elements may be arranged side-by-side. The two or more strap elements may be arranged symmetrically, for example at equal distances from the longitudinal axis of the pole, to obtain a symmetric tensile element.
Additionally or alternatively, the two or more strap elements may overlap. For example, first loops may partially or fully overlap at the column connection and/or second loops may partially or fully overlap at the base connection.
A strap element is relatively wide, compared to its thickness. This offers the effect that the strap element can be folded conveniently about a single, i.e. width axis only. The width of the strap elements may be about 5 to 25 times, such as 10 to 20 times larger than the thickness.
In particular, a total width of the strap element, i.e. a sum of the widths of the two or more strap elements when multiple strap elements are used, may be about 10 to 20 times larger than their thickness.
Furthermore, the large width of the strap element may provide a benefit over a thin cable or wire, since it reduces the risk of cutting the column and the vehicle during tensioning. Hence, a thin cable may splice to a metallic column relatively easily, offering a risk of cutting for passengers in the car. Furthermore, the cutting may negatively influence the amount of kinetic energy that can be absorbed. The strap element, instead, is relatively wide, which reduces the risk of cutting, thereby improving the unfolding and absorption of kinetic energy.
The loops of the strap element may be provided around the base connection and the column connection, which may be embodied as a transverse rod. This may offer a reliable connection between the strap element and the column or the base.
In an embodiment, the tensile element is substantially elastic in the longitudinal direction.
The elasticity of the tensile element, for example when the tensile element were to be a strap element, allows further kinetic energy to be absorbed when the tensile element is unfolded and elongated elastically afterwards. This may further reduce the exit velocity of the vehicle by converting kinetic energy of the vehicle into elastic energy in the tensile element.
In an embodiment, the tensile element comprises a polymeric material, preferably a polyester material, for example being made entirely of a polyester material. It was found by the inventors that the polymeric material is beneficial for folding upon installation and for unfolding in case of a vehicle colliding with pole. Furthermore, a polymeric material is relatively strong, being able to accommodate the relatively large stresses occurring during a collision, and lightweight, allowing the tensile element to be installed more conveniently.
In addition, polymeric materials, especially comprising polyester material, e.g. a strap element made of polyester material, have the benefit that they are relatively resistant against cutting. Hence, the ruptured ends of the pole may be sharp and could otherwise cut the tensile element. However, the polymeric material may be prone to such cutting, offering a more reliable operation.
Further benefits of a polymeric tensile element are that they are not prone to corrosion, which would be the case with steel cables, especially galvanic corrosion between a steel cable and an aluminium base and/or column. Furthermore, polymeric tensile elements are more resistant against moisture, frost, temperature variations, chemical substances and UV radiation. In addition, polymeric tensile element are insulating, both thermally and electrically.
Accordingly, these polymeric tensile elements are relatively durable and may increase the lifetime of the utility pole.
In an embodiment, the pole base further comprises: - a hollow base tube, extending in the longitudinal direction, and - an anchor plate, configured to be inserted in the ground, extending substantially in a transverse plane perpendicular to the longitudinal direction, wherein the anchor plate extends outside the base tube, seen in the transverse plane, and wherein the base connection is provided at the plate.
The hollow base tube may be similar to existing utility poles and may be installed vertically in the ground. As such, the base tube is aligned parallel to the longitudinal direction. The anchor plate is aligned perpendicular to the longitudinal direction, i.e. horizontally in the transverse plane, and projects beyond the perimeter of the hollow base tube in the transverse plane. As such, the anchor plate is configured to form an anchor in the ground, against upward pulling in the longitudinal direction. As a result of the larger projection of the anchor plate, i.e. beyond the hollow base tube, the anchor plate is able to take up larger upward forces than the hollow base tube itself.
To this effect, the base connection is provided at the anchor plate, so that the tensile element can be anchored in the ground better, compared to when it were to be connected to the base tube. A further benefit is provided, since the pole does not need to rupture by the collision to facilitate unfolding of the tensile element. Instead, the entire column and the hollow base tube can be pulled out of the ground following the collision. The anchor plate will thereby remain in the ground, holding the base connection stationary, so that the tensile element is unfolded when the column is pulled out of the ground.
The anchor plate may be installed below the hollow base tube, for example in a way that the base tube vertically rests on the anchor plate. The anchor plate may be mechanically disconnected from the hollow base tube, so that any upward movement of the base tube will not adjust the position of the anchor plate.
In an embodiment, the hollow base tube is slidable relative to the anchor plate parallel to the longitudinal direction. This sliding connection offers mutuals displacements between the anchor plate and the hollow base tube. Should the position of the hollow base tube be changed, i.e. parallel to the longitudinal direction, the anchor plate would remain in place and would remain in function for tensioning the tensile element in the case of a collision.
This may be beneficial when the column and the base remain connected upon collision, either or purpose or not. For example, in case the pole were to be unitary with an integral base and column, the entire pole can be pulled out of the ground upon impact. Furthermore, the hollow base tube may deform when being pulled out of the ground entirely, which deformation may further contribute in reducing the vehicle’s velocity.
In an embodiment, the anchor plate is mechanically disconnected from the hollow base tube. This may give the effect that a change in position of the hollow base tube will not affect the position of the anchor plate in any direction.
No direct mechanical interaction may be present between the anchor plate and the hollow base tube. At most, however, the hollow base tube may vertically rest on the anchor plate.
However, this resting contact may have no effect when the hollow base tube is upwardly pulled out of the ground.
In a further embodiment, the anchor plate comprises a central aperture, wherein the anchor plate is configured to receive the base tube in the central aperture. According to this embodiment, the anchor plate does not necessarily need to be provided below the hollow tube, with the hollow base tube resting on the anchor plate. Instead, the hollow base tube may be inserted in the central aperture in the anchor plate, so that the anchor plate can be positioned at any position along the height of the base tube.
According to this embodiment, the anchor plate may also interlock with the hollow base tube, instead of only with the tensile element, to prevent the base tube from being pulled out of the ground by means of the anchor plate.
In a further embodiment, the base connection may be embodied as a transverse metal rod that may be fastened to the anchor plate by means of U-shaped clamping bolts. The metal rod may extend across the central aperture in the anchor plate, so that the rod can pass underneath the hollow base tube. Alternatively, the hollow base tube may comprise two opposed openings through which the rod can extend, so that the rod passes through the interior of the hollow base tube.
In an embodiment, the anchor plate may be made of a material different from the material from which the base tube and/or the column is made. The anchor plate may for example be made of a non-metallic material, such as a high-density polyethylene (HDPE) material. The non-metallic anchor plate may offer the benefit that it may be prone to corrosion, or degradation in any other way, to a lesser extent and that it may be less expensive.
In an embodiment, the pole further comprises a hollow ground level tube, located inside the base and/or the column, wherein the ground level tube crosses the ground level in an installed configuration of the pole, and wherein the ground level tube surrounds the tensile element at least partially.
The hollow ground level tube is configured to strengthen the pole at least at the ground level, where the pole is most likely prone to an impact of a vehicle colliding with the pole. From this point of view, it is desirable to strengthen the pole to be able to absorb a larger amount of kinetic energy from the vehicle, compared to when no ground level tube were to be provided.
Upon impact of the vehicle, the ground level tube is configured to deform in conjunction with the column and/or the base, to improve the deformation resistance. Furthermore, the ground level tube may prevent the pole from being ruptured due to the increased stiffness added by the ground level tube.
The ground level tube may be provided concentrically with the column and/or the base, for example being arranged closely against the inner surface of the column and/or the base.
Preferably, the ground level tube spans across a coupling assembly between the column and the base to strengthen the coupling assembly, which would otherwise be a relatively weak point and/or to provide additional protection to the tensile element.
Optionally, the ground level tube may be connected to the anchor plate, so that the ground level tube can be prevented from being pulled upwardly as a result from a counter force by the anchor plate. The ground level tube may extend through the central aperture in the anchor plate. As such, the ground level tube may be connected to the anchor plate by means of the transverse metal rod that can also be used to connect the anchor plate to the hollow base tube.
In an embodiment, the anchor plate comprises a central aperture, wherein the anchor plate is configured to receive the hollow ground level tube in the central aperture. According to this embodiment, the anchor plate does not necessarily need to be provided below ground level tube, with the hollow base tube resting on the anchor plate. Instead, the ground level tube may beinserted in the central aperture in the anchor plate, so that the anchor plate can be positioned at any position along the height of the ground level tube.
According to this embodiment, the anchor plate may also interlock with the ground level tube, to prevent the ground level tube from being pulled out of the ground by means of the anchor plate.
In a further embodiment, the base connection may be embodied as a transverse metal rod that may be fastened to the anchor plate by means of U-shaped clamping bolts. The metal rod may extend across the central aperture in the anchor plate, so that the rod can pass underneath the ground level tube. Alternatively, the ground level may comprise two opposed openings through which the rod can extend, so that the rod passes through the interior of the ground level tube.
In a further embodiment, the anchor plate interlocks with the ground level tube, the anchor plate receives the hollow ground level tube in the central aperture and the hollow base tube is positioned above the anchor plate. This way, the utility pole may be installed and/or removed relatively easily.
In an embodiment, the ground level tube is made of different material than the base and/or the column, preferably made of a softer material, for example made of a polymeric material, such as high-density polyethylene (HDPE). The softer material used for the ground level tube may provide for a different deformation behaviour, compared to the column and the base alone, for example offering a larger shear flow rate to absorb kinetic energy over a larger deformation strain.
In addition, the polymeric ground level tube may prevent the tensile element from getting into contact with the column and the base, i.e. which are generally made of a metallic material, after a vehicle collides with the pole. This may prevent the tensile element from being cut by metallic parts of the pole. Instead, the polymeric ground level tube may be softer to introduce less damage to the ground level tube.
In an embodiment, the pole further comprises a strengthening tube, located inside the column, wherein the strengthening tube surrounds the tensile element at least partially, and wherein the column connection is provided through the strengthening tube. The strengthening tube may be arranged at least partially above the ground level and is configured to strengthen the column, for improving the column’s resistance against a collision. The strengthening tube may be provided concentrically with the column, for example being arranged closely against the inner surface of the column wall. As a result, the wall thickness of the column wall is increased locally by the strengthening tube. The strengthening tube may be expanded inside the column, to allow for a tight fit inside the column.
The strengthening tube may be beneficial, since it may not be necessary to provide the entire column with the large wall thickness. Only the critical parts of the column may be provided with the strengthening tube, to limit the amount of material that needs to be used for manufacturing the pole.
The column connection may be provided at the strengthening tube, so that the tensile element is attached to the column at a relatively strong part of the column. The column connection may be embodied as a transverse rod, such as a transverse bolt, which may be fastened through opposed openings in the column and the strengthening tube, being secured with a nut.
A transverse bolt forming the column connection may optionally be provided with a bushing around it, i.e. between the bolt's screw thread and the tensile element. The bushing may reduce the chances of damaging of the tensile element by the screw thread.
In an embodiment, in an installed configuration of the pole, a lower end of the strengthening tube may be located above an upper end of the ground level tube to avoid interference therebetween. In particular, a diameter of the strengthening tube may be approximately equal to a diameter of the ground level tube.
In an embodiment, the column is provided with an access port in the column wall, to access the interior of the column and possible electric components located in the interior of the column. The strengthening tube may be provided in the column at the location where the access port is provided, to strengthen the column around the access port, since that would otherwise become a weak point. The strengthening tube may be provided with a similar opening, to provide a passage towards the column interior.
The access port may be provided with a removable closure, to close off the access port.
The opening in the strengthening tube may be dimensioned smaller than the access port, so that the closure can be placed against the strengthening tube inside the access port.
The strengthening tube may be asymmetric along the longitudinal direction, for example having a larger, e.g. higher portion above the access port, compared to the portion located below the access port.
In an embodiment, the pole further comprises a coupling assembly in between the base and the column, configured to break upon impact of the vehicle colliding with the utility pole.
The coupling assembly may be configured to form a controlled point where the pole may break upon impact by a vehicle colliding with the pole. As a result of this predicted rupture point, the unfolding of the tensile element and tensioning thereof may be controlled more accurately, to improve the absorption of kinetic energy.
The coupling assembly may be provided at the ground level, so that the base is arranged in the ground entirely and that column is arranged above the ground level entirely. Alternatively, the coupling assembly may be provided below the ground level, so that the column is arranged in the ground partially, or above the ground level, so that the base protrudes out of the ground partially.
In a further embodiment, the base comprises an upper end portion wherein the column comprises a bottom end portion, facing the upper end portion, and wherein the coupling assembly is a shear-off coupling assembly, comprising a plurality of holding elements configured to hold the bottom end portion and the upper end portion against each other until a transverse stress between the base and the column exceeds a threshold stress, ie. during collision of a vehicle.
The shear-off coupling assembly may be arranged above the ground level, for example at a level corresponding to a typical height of a front bumper of a car. The shear-off coupling assembly may offer the benefit that it is configured to hold the base and the column together in the installed configuration of the pole.
Upon impact of a vehicle, the holding elements become subject to a horizontal shear stress between the base and the column. As soon as the shear stress exceeds a threshold shear stress, the holding elements may become loosened, releasing the connection between the base and the column. Accordingly, the pole may be configured to absorb a relatively low amount of kinetic energy from the vehicle, which may be beneficial when it is desired not to decelerate the vehicle too much upon impact.
In a further or alternative embodiment, the coupling assembly comprises a bolted connection between the base and the column, and wherein the bolted connection is configured to rupture when the transverse stress exceeds the threshold stress. The pole may thereto comprise opposed flanges attached to the column and the base, which may be fastened to each other by means of multiple bolts. The bolts may be selected in correspondence with an intended failure criterium for the coupling assembly, so that the bolted connection is configured to rupture in case a vehicle collides with the pole, when the transverse stress exceeds the threshold stress.
Optionally, one of the flanges of the utility pole may be made of a relatively strong and/or ductile material, whereas the other one of the flanges may be made of a relatively weak and/or brittle material. The bolts may fasten both flanges to each other. Upon impact of a vehicle into the pole, the brittle one of the flanges may rupture upon impact, due to the high forces that occur. This may rupture the connection between the base and the pole, to allow the pole to be taken along by the vehicle.
In an alternative embodiment, the base and the column are formed as a unitary utility pole, e.g. being integrally connected to each other. The base and the column may be formed by one and the same piece, for example being manufactured integrally, for example by means of an extrusion process.
In the utility pole according to this embodiment, the pole base may be defined as the part of the unitary pole being arranged in the ground, i.e. below the ground level. Similarly, the pole column may be defined as the part of the unitary pole being arranged above the ground, i.e. above the ground level.
In a further embodiment, the pole base may comprise a solid base block, for example may of a relatively heavy material, such as concrete. The base block may be buried in the ground to form a foundation for the pole. The base connection for the tensile element may be provided at the base block, so that the tensile element can be tensioned upon collision with respect to the base block.
According to a second aspect, the present invention provides an energy-absorbing utility pole, for example a traffic light pole, a street lighting pole, a vehicle charging station and/or a traffic sign support, for absorbing kinetic energy of a vehicle colliding with the utility pole, the utility pole comprising: - a hollow pole base, configured to be inserted in the ground for securing the utility pole with respect to the ground, - a hollow tubular column, connected to the base and extending away from the base in a longitudinal direction of the pole, - a tensile element, located in the base and the column, wherein the tensile element is connected to the base at a base connection and to the column at a column connection, wherein the tensile element has a length larger than a connection distance between the base connection and the column connection, and wherein the difference between the length of the tensile element and the connection distance provides an excess length of the tensile element to provide a time delay for tightening the tensile element upon collision of the vehicle into the utility pole, characterized in that the hollow pole base comprises: - a hollow base tube, extending in the longitudinal direction, and - an anchor plate, configured to be inserted in the ground, extending substantially in a transverse plane perpendicular to the longitudinal direction,
wherein the anchor plate extends outside the base tube, seen in the transverse plane, and wherein the base connection is provided at the plate.
The utility pole according to the second aspect of the invention may comprise one or more of the features and/or benefits disclosed herein in relation to the utility pole according to the first aspect of the invention, in particular as recited in the claims. Especially, all features and benefits disclosed in relation to claim 1 can apply mutatis mutandis for the utility pole according to this second aspect.
The hollow base tube of this utility pole may be similar to existing utility poles and may be installed vertically in the ground. As such, the base tube is aligned parallel to the longitudinal direction. The anchor plate is aligned perpendicular to the longitudinal direction, i.e. horizontally in the transverse plane, and projects beyond the perimeter of the hollow base tube in the transverse plane. As such, the anchor plate is configured to form an anchor in the ground, against upward pulling in the longitudinal direction. As a result of the larger projection of the anchor plate, i.e. beyond the hollow base tube, the anchor plate is able to take up larger upward forces than the hollow base tube itself.
To this effect, the base connection is provided at the anchor plate, so that the tensile element can be anchored in the ground better, compared to when it were to be connected to the base tube. A further benefit is provided, since the pole does not need to rupture by the collision to facilitate unfolding of the tensile element. Instead, the entire column and the hollow base tube can be pulled out of the ground following the collision. The anchor plate will thereby remain in the ground, holding the base connection stationary, so that the tensile element is unfolded when the column is pulled out of the ground.
The anchor plate may be installed below the hollow base tube, for example in a way that the base tube vertically rests on the anchor plate. The anchor plate may be mechanically disconnected from the hollow base tube, so that any upward movement of the base tube will not adjust the position of the anchor plate.
In an embodiment, the hollow base tube is slidable relative to the anchor plate parallel to the longitudinal direction. This sliding connection offers mutuals displacements between the anchor plate and the hollow base tube. Should the position of the hollow base tube be changed, i.e. parallel to the longitudinal direction, the anchor plate would remain in place and would remain in function for tensioning the tensile element in the case of a collision.
This may be beneficial when the column and the base remain connected upon collision, either or purpose or not. For example, in case the pole were to be unitary with an integral base and column, the entire pole can be pulled out of the ground upon impact. Furthermore, the hollow base tube may deform when being pulled out of the ground entirely, which deformation may further contribute in reducing the vehicle's velocity.
In an embodiment, the anchor plate is mechanically disconnected from the hollow base tube. This may give the effect that a change in position of the hollow base tube will not affect the position of the anchor plate in any direction.
No direct mechanical interaction may be present between the anchor plate and the hollow base tube. At most, however, the hollow base tube may vertically rest on the anchor plate.
However, this resting contact may have no effect when the hollow base tube is upwardly pulled out of the ground.
In an embodiment, the pole further comprises a hollow ground level tube, located inside the base and/or the column, wherein the ground level tube crosses the ground level in an installed configuration of the pole, and wherein the ground level tube surrounds the tensile element at least partially.
The hollow ground level tube is configured to strengthen the pole at least at the ground level, where the pole is most likely prone to an impact of a vehicle colliding with the pole. From this point of view, it is desirable to strengthen the pole to be able to absorb a larger amount of kinetic energy from the vehicle, compared to when no ground level tube were to be provided.
Upon impact of the vehicle, the ground level tube is configured to deform in conjunction with the column and/or the base, to improve the deformation resistance. Furthermore, the ground level tube may prevent the pole from being ruptured due to the increased stiffness added by the ground level tube.
The ground level tube may be provided concentrically with the column and/or the base, for example being arranged closely against the inner surface of the column and/or the base.
Preferably, the ground level tube spans across a coupling assembly between the column and the base to strengthen the coupling assembly, which would otherwise be a relatively weak point and/or to provide additional protection to the tensile element.
Optionally, the ground level tube may be connected to the anchor plate, so that the ground level tube can be prevented from being pulled upwardly as a result from a counter force by the anchor plate. The ground level tube may extend through the central aperture in the anchor plate. As such, the ground level tube may be connected to the anchor plate by means of the transverse metal rod that can also be used to connect the anchor plate to the hollow base tube.
In an embodiment, the anchor plate comprises a central aperture, wherein the anchor plate is configured to receive the base tube and/or the hollow ground level tube in the central aperture. According to this embodiment, the anchor plate does not necessarily need to be provided below the base tube and/or the ground level tube, respectively, with the respective tube resting on the anchor plate. Instead, the hollow base tube and/or the ground level tube may be inserted in the central aperture in the anchor plate, so that the anchor plate can be positioned at any position along the height of the base tube and/or the ground level tube.
According to this embodiment, the anchor plate may also interlock with the hollow base tube and/or the ground level tube, instead of only with the tensile element, to prevent the base tube from being pulled out of the ground by means of the anchor plate.
In a further embodiment, the anchor plate interlocks with the ground level tube, the anchor plate receives the hollow ground level tube in the central aperture and the hollow base tube is positioned above the anchor plate. This way, the utility pole may be installed and/or removed relatively easily.
In a further embodiment, the base connection may be embodied as a transverse metal rod that may be fastened to the anchor plate by means of U-shaped clamping bolts. The metal rod may extend across the central aperture in the anchor plate, so that the rod can pass underneath the hollow base tube. Alternatively, the hollow base tube may comprise two opposed openings through which the rod can extend, so that the rod passes through the interior of the hollow base tube.
In an embodiment, the anchor plate may be made of a material different from the material from which the base tube and/or the column is made. The anchor plate may for example be made of a non-metallic material, such as a high-density polyethylene (HDPE) material. The non-metallic anchor plate may offer the benefit that it may be prone to corrosion, or degradation in any other way, to a lesser extent and that it may be less expensive.
According to a further aspect, the present invention provides a method of installing a utility pole according to any of the preceding claims, comprising the steps of: - arranging the base in the ground, - arranging the column on the base, and - connecting the tensile element to the base at the base connection and to the column at the column connection.
The method according to the third aspect of the invention may comprise one or more of the features and/or benefits disclosed herein in relation to the utility poles according to the first or second aspect of the invention, in particular as recited in the claims.
According to the present method, the installation of the utility pole additionally comprises the step of connecting the tensile element, relative to known other method for installing utility poles. The tensile element may be connected to the column and the base after both have been aranged at the intended location. Alternatively, however, the tensile element may be connected to the column and the base before the base in arranged in the ground. The latter may be especially beneficial where the utility pole is a unitary utility pole, which can be assembled conveniently prior to installation.
In an embodiment of the method, the step of connecting the tensile element to the base connection is carried out prior to the step of arranging the base in the ground. In an embodiment of the method, the step of connecting the tensile element to the column connection is carried out after the steps of arranging the base in the ground and arranging the column on the base.
Alternatively or additionally, the column comprises an access port in the column wall and the step of connecting the tensile element to the column connection may be carried out through the access port. To effect this connection, a person may position the tensile element inside the column with one hand, having their arm protruding through the access port. With their other hand, the person may, for example, protrude the transverse rod through the column to fix the tensile element to the column. This way of installing the utility pole may be more user-friendly than existing methods for installing existing utility poles, since, for example, the tensile element can be connected to the column when the column is erected. However, this step may be done at a small height above ground level, instead of high above the ground, as in the prior art.
In an embodiment wherein the utility pole comprises an anchor plate and a ground level tube, the step of arranging the base in the ground may comprise the steps of interlocking the anchor plate and the ground level tube, arranging the anchor plate in the ground, and, optionally at a later stage, positioning the hollow base tube over the ground level tube. This way, installation and/or removal of the pole base may be performed relatively easily as the anchor plate and ground level may be arranged in the ground in an earlier stage and function as a guide for positioning the base tube over the ground level tube, for example above the anchor plate.
Brief description of drawings
Further characteristics of the invention will be explained below, with reference to embodiments, which are displayed in the appended drawings, in which:
Figure 1 schematically depicts an embodiment of a utility pole comprising a hollow pole base;
Figure 2 schematically depicts another embodiment of a utility pole;
Figure 3A schematically depicts an embodiment of a tensile element comprising a strap element;
Figure 3B schematically depicts an embodiment of a tensile element comprising two strap elements;
Figure 3C schematically depicts a side view of the tensile elements of Figure 3A and 3B, when bundled and connected inside an utility pole,
Figure 4A schematically depicts an enlarged view of section E of Figure 3C;
Figure 4B schematically depicts an embodiment of an anchor plate;
Figure 4C schematically depicts an assembly comprising a tensile element, ground level tube and an anchor plate;
Figure 4D schematically depicts the assembly of Figure 4C, provided with a column of a utility pole; and
Figure 5 schematically depicts the utility pole according to the embodiment of Figure 1, after collision with a vehicle
Throughout the figures, the same reference numerals are used to refer to corresponding components or to components that have a corresponding function.
Detailed description of embodiments
Figure 1 schematically depicts an embodiment of a utility pole 1, in particular a street lighting pole. The utility pole 1 comprises a hollow pole base 2, configured to be inserted in the ground for securing the utility pole 1 with respect to the ground. The pole base 2 is arranged in the ground at least partially in the installed configuration of Fig. 1, protruding partially out of the ground, thereby crossing the ground level G. The base 2 is configured to form a foundation for the pole 1, to hold the pole 1 substantially upright in the installed configuration.
The utility pole 1 comprises a hollow tubular column 3. The column 3 is connected to the base 2 and extends aways from the base 2 in a vertically upward direction to form the support for streetlighting armature 9. This upward direction defines a longitudinal direction L of the pole 1, which is substantially vertical. The column 3 and the base 2 are at least partially made of extruded aluminium.
The utility pole 1 also comprises a tensile element 4, located in the base 2 and the column 3. The tensile element 4 is connected to the base 2 at a base connection 21 and to the column at a column connection 31, and has a length larger than a connection distance CD between the base connection 21 and the column connection 31.
The difference between the length of the tensile element 4 and the connection distance
CD provides an excess length of the tensile element to provide a time delay for tightening the tensile element 4 upon collision of a vehicle 99into the utility pole 1.
The excess length of the tensile element 4 is accommodated in between the base connection 21 and the column connection 31. At least part 41 of the tensile element 4 is folded parallel to the longitudinal direction L to accommodate the excess length in between the base connection 21 and the column connection 31. The folded part 41 extends alternately upward and downward, in between folds 42
The base connection 21 is formed by a transverse rod that extends through the base 2, in a transverse direction perpendicular to the longitudinal direction L. The column connection 31 is located above the ground level G and is also formed by a transverse rod that extends through the hollow column 3 in the transverse direction.
The folded part 41 of the tensile element 4 is located at a lower end of the tensile element 4, close to the base connection 21, and entirely inside the pole base 2. The folded part 41 comprises an even number of folds 42, in particular four folds 42. From the column connection 31, the tensile element 4 extends downwards to a first fold, where the tensile element is folded upwards towards a second fold, where the tensile element is folded downward, to extend towards a third fold, and again upwards towards a fourth fold, after which the tensile element 4 extends downward towards the base connection 21.
The folded part 41 may also be located at an upper end of the tensile element, close to the column connection 31 and inside the column 3. The tensile element 4 may comprise more than a single folded part 41, such as a first folded part at its lower end and a second folded part at its upper end.
The folded part 41 is located entirely below the ground level G but may also cross the ground level G. The folded part 41 may be bundled by means of additional element 43, such as a band or tape, that encircles all upward and downward lengths between the folds 42 of the folded part 41. The additional element 43 is configured to rupture when the tensile element is unfolded after impact. Alternatively, no or multiple additional elements 43 may be provided, as depicted in Fig. 3C.
The connection distance is between 30% and 60%, in particular between 40% and 50%, for example about 45% of the length of the tensile element 4 in the longitudinal direction
L. As such, the excess length of the tensile element 4 is between 70% to 40% of the length of the tensile element 4.
In this embodiment, the column has an overall height of 12 meters above the ground level G and the pole base 2 is inserted in the ground about 2 meters below the ground level
G. The base connection 21 is provided at a bottom end of the pole base 2 and the column connection 31 is provided about 2 meters above the ground level G. The connection distance
CD is 4 meters. The tensile element 4 has a length of 10 meters, thus an excess length of 6 meters. Each one of the upward and downward lengths of the folded part has an individual length of about 1.5 meters.
The tensile element 4 comprises at least one strap element 44, 44’, for example a single strap element 44 as depicted in Fig. 3A, or multiple strap elements 44’ arranged side-by-side,
as depicted in Fig. 3B. Each strap element 44, 44’ comprises a first loop 45 surrounding the column connection 31 and an opposed second loop 46 surrounding the base connection 21.
The two or more strap elements 44° may be arranged symmetrically, for example at equal distances from the longitudinal axis L of the pole. The width of the strap elements 44, 44 is about 5 to 25 times larger than their thickness. In particular, the width of the strap element 44 is about 10 to 20 times larger than its thickness and the sum of the widths of the two or more strap elements 44’ is about 10 to 20 times larger than their thickness.
The tensile element 4 is substantially elastic in the longitudinal direction L and comprises a polymeric material, in particular a polyester material. The tensile element 4 is entirely made of the polyester material.
The pole base 2 is a hollow base, formed by a hollow tube inserted into the ground, integral with the column 3. The pole base 2 comprises a hollow base tube 22 extending in the longitudinal direction and an anchor plate 23, configured to be inserted in the ground, and to form an anchor in the ground, against upward pulling in the longitudinal direction. The anchor plate 23 extends substantially in a transverse plane perpendicular to the longitudinal direction
L, outside the base tube 22, seen in the transverse plane. The anchor plate is aligned perpendicular to the longitudinal direction L, i.e. horizontally in the transverse plane, and projects beyond the perimeter of the hollow base tube 22 in the transverse plane. As such, the anchor plate is configured to form an anchor in the ground, against upward pulling in the longitudinal direction. The base connection 21 is provided at the plate 23.
The anchor plate 23 is installed below the base tube 22 and mechanically disconnected from the hollow base tube 22, so that any upward movement of the base tube will not adjust the position of the anchor plate 23. As such, the hollow base tube 22 is slidable relative to the anchor plate 23 parallel to the longitudinal direction L. In another embodiment, the hollow base tube may be slidably mechanically connected to the anchor plate, for example via slotted holes.
An embodiment of an anchor plate 23 is depicted in Fig. 4B. The anchor plate comprises a central aperture 24, and the anchor plate 23 is configured to receive the ground level tube 5 in the central aperture 24, for example by having a corresponding shape. Additionally or alternatively, the anchor plate 23 may be configured to receive the hollow base tube 22 in the central aperture 24.
The base connection 21 is embodied as a transverse metal rod 25 fastened to the anchor plate 23 by means of U-shaped clamping bolts 26. The U-shaped clamping bolts 26 clamp the metal rod 25 to the anchor plate 23 by means of nuts 27.
The anchor plate 23 is made of a non-metallic material, such as high-density polyethylene (HDPE).
The pole 1 further comprises a hollow ground level tube 5, located inside the base 2 and the column 1. The ground level tube 5 crosses the ground level in an installed configuration of the pole 1, and surrounds the tensile element 4 at least partially. The ground level tube 5 extends above the ground level G and is configured to strengthen the pole at least at the ground level. The ground level tube 5 is provided concentrically with the column 3 and the base 2, for example being arranged closely against the inner surfaces thereof.
The base 2 and the column 3 are formed as a unitary utility pole, e.g. being integrally connected to each other. The base 2 and the column 3 are formed by one and the same piece, being manufactured integrally by means of an extrusion process.
The ground level tube 5 extends through the central aperture 24 in the anchor plate and is connected to the anchor plate 23 by means of the metal rod that forms the base connection 21. The ground level tube 5 comprises two opposed openings 51 through which the rod extends and interlocks with the ground level tube 5.
In other embodiments, the ground level tube 5 may be omitted and, for example, the base tube 22 may be arranged in the central aperture 24.
The ground level tube 5 is made of a softer material than the base 2 and the column 3, in particular a polymeric material, such as a HDPE.
The pole 1 further comprises a strengthening tube 6, located inside the column 3, wherein the strengthening tube 6 surrounds the tensile element 4 at least partially, and wherein the column connection 31 is provided through the strengthening tube 6. The strengthening tube 6 is arranged at least partially, in particular completely, above the ground level G and is configured to strengthen the column 2, for improving the column’s resistance against a collision.
The strengthening tube 6 is provided concentrically with the column 2 by being arranged closely against the inner surface of the column wall to locally increase the column 3 wall thickness with strengthening tube 6. The strengthening tube 6 is expanded inside the column 2 to achieve a tight fit inside the column.
The column connection 31 is formed by a transverse rod 32, such as a transverse bolt, which may be fastened through opposed openings 33 in the column 3 and the strengthening tube 8, being secured with a nut 35. The transverse bolt is provided with a bushing 35 around it between the bolt’s screw thread and the tensile element 4. The bushing 35 may reduce the chances of damaging of the tensile element 4 by the screw thread.
The column 3 is provided with an access port 7 in the column wall, to access the interior of the column 3 and possible electric components located in the interior of the column 3. The strengthening tube 6 is provided in the column 3 at the location where the access port 7 is provided, to strengthen the column 3 around the access port. The strengthening tube 6 is provided with a similar opening 61, to provide a passage towards the column interior.
The access 7 port is provided with a removable closure 71, to close off the access port 7. The opening 61 in the strengthening tube 6 is dimensioned smaller than the access port 7, so that the closure 71 can be placed against the strengthening tube 6 inside the access port 7.
The strengthening tube 6 is asymmetric along the longitudinal direction L and has a larger, e.g. higher portion above the access port 7, compared to the portion located below the access port 7.
Figure 2 schematically depicts another embodiment of an utility pole 1. The pole base 2 comprises a solid base block 28, for example may of a relatively heavy material, such as concrete. The base block 28 is buried in the ground to form a foundation for the pole 1. The base connection 21 for the tensile element 4 is provided at the base block 28, so that the tensile element 4 can be tensioned upon collision with respect to the base block 28. The base may also have another shape and/or be part of a road structure, such as a viaduct or the like.
The pole 1 further comprises a coupling assembly 8 in between the base 2 and the column 3, configured to break upon impact of the vehicle colliding with the utility pole 1. The coupling assembly 8 is configured to form a controlled point where the pole may break upon impact by a vehicle colliding with the pole 1.
The coupling assembly 8 is provided below the ground level G, so that the column 3 is arranged in the ground partially. Alternatively, the coupling assembly may be arranged above the ground level G or at the ground level G.
The coupling assembly 8 comprises a bolted connection 81 between the base 2 and the column 3, and the bolted connection 81 is configured to rupture when a transverse stress exceeds the threshold stress. The pole 3 comprises opposed flanges 82 attached to the column 3 and the base 2, which are fastened to each other by means of multiple bolts 81 that are selected in correspondence with an intended failure criterium for the coupling assembly 8, so that the bolted connection 81 is configured to rupture in case a vehicle collides with the pole, when the transverse stress exceeds the threshold stress. One of the flanges 82 may be made of a relatively strong and/or ductile material, whereas the other one of the flanges may be made of arelatively weak and/or brittle material.
In an alternative embodiment, the base 2 comprises an upper end portion and the column 3 comprises a bottom end portion, facing the upper end portion, wherein the coupling assembly 8 is a shear-off coupling assembly comprising a plurality of holding elements configured to hold the bottom end portion and the upper end portion against each other until a transverse stress between the base and the column exceeds a threshold stress, i.e. during collision of a vehicle.
In some embodiments, the ground level tube 5 may span across the coupling assembly 8.
The utility pole 1 may be installed by arranging the base 2 in the ground, arranging the column 3 on the base, and connecting the tensile element 4 to the base 2 at the base connection 21 and to the column 3 at the column connection 31.
The tensile element 4 may be connected to the base connection 21 and/or to the column connection 31 prior to arranging the base 2 in the ground and/or prior to arranging the column 3 on the base. The tensile element 4 may for example be connected to the transverse bolt 32 through the access port 7.
Furthermore, prior to installation of the base 2 in the ground, the anchor plate 4 and the ground level tube 5 may be interlocked, for example by arranging the transverse rod 25 through openings in the ground level tube 5. Optionally, the at least one tensile element 4 is connected simultaneously, for example by advancing the transverse rod 25 through second loop 46. This may then result in the assembly of Fig. 4C, which may be arranged in the ground prior to the base tube and/or the column 3. At a later stage, the base tube 22 and the column 3 may be positioned over the ground level tube 5, which then functions as a guide, to result in the assembly of Fig. 4D. After connecting the column connection 31 and/or electric connections, the access port 7 may be closed with closure 71.
As depicted in Fig. 5, kinetic energy of a vehicle, by reducing the velocity of the vehicle 99 is absorbed as when a vehicle collides with the pole 1, the pole 1 may deform and rupture, reducing the velocity of the vehicle 99. Alternatively, the entire column 3 may be pulled out of the ground following the collision.
After rupture and/or pull-out of the pole 1, the column 3 may be taken along with the vehicle 99 and may be separated from the base 2, which remains in the ground. This may have the effect that the distance between the base connection 31 and the pole connection 21 becomes larger than in the installed configuration of the pole 1.
The anchor plate 23 remains in the ground, holding the base connection stationary, so that the tensile element 4 is unfolded. As the tensile element 4 is folded parallel to the longitudinal direction, the tensile element is unfolded in a direction parallel to the hollow interior of the base 2 and/or the column 3. The tensile element 4 does not need to pass a tight space between the column wall and the column connection 31 and/or the base wall and the base connection 21.
As a result, the tensile element 4 will be tensioned when the distance between the base connection and the pole connection becomes equal to the length of the tensile element 4, and a second mode of energy absorption is initiated by the pole 1, since the column 3 may deform in front of the vehicle 99. This deformation will absorb additional kinetic energy, thereby further reducing the velocity of the vehicle. However, the tensioning of the tensile element will be delayed relative to the moment of rupture as a result of the excess length of the tensile element 4.

Claims (17)

CONCLUSIESCONCLUSIONS 1. Energie-absorberende elektriciteitsmast, bijvoorbeeld een verkeerslichtmast, een straatverlichtingsmast, een oplaadstation voor voertuigen en/of een steun voor verkeersborden, voor het absorberen van kinetische energie van een voertuig dat tegen de elektriciteitsmast botst, waarbij de elektriciteitsmast omvat: - een mastbasis, ingericht om in de grond te worden gebracht om de elektriciteitsmast vast te zetten ten opzichte van de grond, - een holle buisvormige kolom, verbonden met de basis en zich in een lengterichting van de mast uitstrekkend vanaf de basis, - een trekelement, dat zich in de basis en de kolom bevindt, waarbij het trekelement is verbonden met de basis bij een basisverbinding en met de kolom bij een kolomverbinding, waarbij het trekelement een lengte heeft die groter is dan een verbindingsafstand tussen de basisverbinding en de kolomverbinding, en waarbij het verschil tussen de lengte van het trekelement en de verbindingsafstand een overlengte van het trekelement verschaft om een tijdvertraging te verschaffen voor het aanspannen van het trekelement bij botsing van het voertuig tegen de elektriciteitsmast, met het kenmerk dat, de overtollige lengte van het trekelement is ondergebracht tussen de basisverbinding en de kolomverbinding, en waarbij ten minste een deel van het trekelement evenwijdig aan de lengterichting is gevouwen om de overlengte tussen de basisverbinding en de kolomverbinding onder te brengen.1. Energy-absorbing electricity pole, for example a traffic light pole, a street lighting pole, a vehicle charging station and/or a traffic sign support, for absorbing kinetic energy from a vehicle colliding with the electricity pole, wherein the electricity pole comprises: - a pole base, designed to be inserted into the ground to fix the electricity pole relative to the ground, - a hollow tubular column, connected to the base and extending in a longitudinal direction of the pole from the base, - a tension element, which extends in the base and the column, where the tension element is connected to the base in a base connection and to the column in a column connection, where the tension element has a length greater than a connection distance between the base connection and the column connection, and where the difference between the length of the tension element and the connection distance provides an excess length of the tension element to provide a time delay for tightening the tension element upon collision of the vehicle against the electricity pole, characterized in that the excess length of the tension element is accommodated between the base connection and the column connection, and wherein at least part of the tensile element is folded parallel to the longitudinal direction to accommodate the excess length between the base connection and the column connection. 2. Elektriciteitsmast volgens conclusie 1, waarbij het gevouwen deel van het trekelement een even aantal vouwen omvat, bijvoorbeeld twee, vier of zes vouwen.2. Electricity mast according to claim 1, wherein the folded part of the tension element comprises an even number of folds, for example two, four or six folds. 3. Elektriciteitsmast volgens conclusie 1 of 2, waarbij het gevouwen deel van het trekelement zich bevindt bij een onderuiteinde van het trekelement.3. Electricity pylon according to claim 1 or 2, wherein the folded part of the tension element is located at a lower end of the tension element. 4. Elektriciteitsmast volgens een van de voorgaande claims, waarbij het gevouwen deel van het trekelement, in een geïnstalleerde toestand van de mast, het maaiveld doorkruist.4. Electricity mast according to any of the preceding claims, wherein the folded part of the tension element, in an installed state of the mast, crosses the ground level. 5. Elektriciteitsmast volgens een van de voorgaande conclusies, waarbij het gevouwen deel van het trekelement is gebundeld, bijvoorbeeld door middel van elastische banden.5. Electricity pylon according to any of the preceding claims, wherein the folded part of the tension element is bundled, for example by means of elastic bands. 6. Elektriciteitsmast volgens een van de voorgaande claims, waarbij de verbindingsafstand tussen 30% en 60%, bij voorkeur tussen 40% en 50%, bijvoorbeeld ongeveer 45% bedraagt van de lengte van het trekelement in de lengterichting.6. Electricity mast according to one of the preceding claims, wherein the connection distance is between 30% and 60%, preferably between 40% and 50%, for example approximately 45% of the length of the tension element in the longitudinal direction. 7. Elektriciteitsmast volgens een van de voorgaande claims, waarbij het trekelement ten minste een riemelement omvat, elk omvattend een eerste lus rond de kolomverbinding en een tegenoverliggende tweede lus rond de basisverbinding.7. Electricity pole according to any of the preceding claims, wherein the tension element comprises at least one belt element, each comprising a first loop around the column connection and an opposing second loop around the base connection. 8. Elektriciteitsmast volgens een van de voorgaande claims, waarbij het trekelement in de lengterichting in hoofdzaak elastisch is.8. Electricity pylon according to one of the preceding claims, wherein the tension element is substantially elastic in the longitudinal direction. 9. Elektriciteitsmast volgens een van de voorgaande conclusies, waarbij het trekelement een polymeermateriaal omvat, bij voorkeur een polyestermateriaal, bijvoorbeeld volledig gemaakt van een polyestermateriaal.9. Electricity pylon according to any of the preceding claims, wherein the tensile element comprises a polymer material, preferably a polyester material, for example made entirely of a polyester material. 10. Elektriciteitsmast volgens een van de voorgaande conclusies, waarbij de basis verder omvat: - een holle basisbuis, die zich uitstrekt in de lengterichting, en - een ankerplaat, ingericht om in de grond te worden gebracht, die zich in hoofdzaak uitstrekt in een dwarsvlak dat loodrecht staat op de lengterichting, waarbij de ankerplaat zich buiten de grondbuis uitstrekt, gezien in het dwarsvlak, en waarbij de basisverbinding is voorzien aan de ankerplaat.10. Electricity pylon according to any of the preceding claims, wherein the base further comprises: - a hollow base tube, which extends in the longitudinal direction, and - an anchor plate, designed to be inserted into the ground, which extends substantially in a transverse plane that is perpendicular to the longitudinal direction, whereby the anchor plate extends outside the ground pipe, seen in the transverse plane, and where the base connection is provided to the anchor plate. 11. Elektriciteitsmast volgens conclusie 10, waarbij de ankerplaat een centrale opening omvat en waarbij de ankerplaat is ingericht om de basisbuis te ontvangen in de centrale opening.11. Electricity mast according to claim 10, wherein the anchor plate comprises a central opening and wherein the anchor plate is designed to receive the base tube in the central opening. 12. Elektriciteitsmast volgens conclusie 10 of 11, waarin de holle basisbuis parallel aan de lengterichting verschuifbaar is ten opzichte van de ankerplaat.12. Electricity pylon according to claim 10 or 11, wherein the hollow base tube is slidable parallel to the longitudinal direction relative to the anchor plate. 13. Elektriciteitsmast volgens een van de conclusies 10 — 12, waarbij de ankerplaat mechanisch is ontkoppeld van de holle basisbuis.13. Electricity mast according to any one of claims 10 - 12, wherein the anchor plate is mechanically decoupled from the hollow base tube. 14. Elektriciteitsmast volgens een van de voorgaande conclusies, verder omvattend een holle maaiveldbuis, die zich binnen de basis en/of de kolom bevindt, waarbij de maaiveldbuis in een geïnstalleerde toestand van de mast het maaiveld doorkruist, en waarbij de maaiveldbuis ten minste gedeeltelijk het trekelement omgeeft.14. Electricity pylon according to any of the preceding claims, further comprising a hollow ground level tube, which is located within the base and/or the column, wherein the ground level tube crosses the ground level in an installed condition of the mast, and wherein the ground level tube at least partially covers the surrounding tensile element. 15. Elektriciteitsmast volgens conclusie 14, waarbij de maaiveldbuis van een ander materiaal is gemaakt dan de basis en/of de kolom, bij voorkeur gemaakt van een zachter materiaal, bijvoorbeeld gemaakt van een polymeermateriaal, zoals hoge- dichtheid polyethyleen (HDPE).15. Electricity pylon according to claim 14, wherein the ground level tube is made of a different material than the base and/or the column, preferably made of a softer material, for example made of a polymer material, such as high-density polyethylene (HDPE). 16. Elektriciteitsmast volgens een van de voorgaande conclusies, verder omvattend een verstevigingsbuis, die zich binnenin de kolom bevindt, waarbij de verstevigingsbuis het trekelement ten minste gedeeltelijk omgeeft, en waarbij de kolomverbinding is voorzien door de verstevigingsbuis.16. Electricity pylon according to any of the preceding claims, further comprising a reinforcing tube located inside the column, wherein the reinforcing tube at least partially surrounds the tensile element, and wherein the column connection is provided by the reinforcing tube. 17. Werkwijze voor het installeren van een elektriciteitsmast volgens een van de voorgaande conclusies, omvattend de stappen van het: - het in de grond aanbrengen van de basis, - het op de basis aanbrengen van de kolom, en - het verbinden van het trekelement aan de basis bij de basisverbinding en aan de kolom bij de kolomverbinding.17. Method for installing an electricity pylon according to any of the preceding claims, comprising the steps of: - arranging the base in the ground, - arranging the column on the base, and - connecting the tension element to the base at the base connection and on the column at the column connection.
NL2032450A 2022-07-12 2022-07-12 Energy-absorbing utility pole NL2032450B1 (en)

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PCT/EP2023/069404 WO2024013269A1 (en) 2022-07-12 2023-07-12 Energy-absorbing utility pole

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838661A (en) * 1972-07-10 1974-10-01 R Medley Post
WO1985002636A1 (en) * 1983-12-13 1985-06-20 Sven Runo Vilhelm Gebelius Device for pole-shaped elements
GB2202564A (en) * 1987-03-20 1988-09-28 Uk Lift Company Limited The Collapsible post
WO2011120069A1 (en) * 2010-04-01 2011-10-06 Michael Griffiths Utility pole
EP2735652A1 (en) * 2012-11-27 2014-05-28 Sapa Profiles NL B.V. A traffic-safe and collision energy absorbing pole
EP3081695B1 (en) 2015-04-13 2019-05-29 Nedal Aluminium B.V. Utility pole with shear off coupling assembly

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838661A (en) * 1972-07-10 1974-10-01 R Medley Post
WO1985002636A1 (en) * 1983-12-13 1985-06-20 Sven Runo Vilhelm Gebelius Device for pole-shaped elements
GB2202564A (en) * 1987-03-20 1988-09-28 Uk Lift Company Limited The Collapsible post
WO2011120069A1 (en) * 2010-04-01 2011-10-06 Michael Griffiths Utility pole
EP2735652A1 (en) * 2012-11-27 2014-05-28 Sapa Profiles NL B.V. A traffic-safe and collision energy absorbing pole
EP2735652B1 (en) 2012-11-27 2018-08-22 Sapa Profiles NL B.V. A traffic-safe and collision energy absorbing pole
EP3081695B1 (en) 2015-04-13 2019-05-29 Nedal Aluminium B.V. Utility pole with shear off coupling assembly

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