EP4675046A1

EP4675046A1 - A collision-yielding post assembly, an elastomeric retention linkage for the post assembly and a method of collision-profing a signpost

Info

Publication number: EP4675046A1
Application number: EP24186147.5A
Authority: EP
Inventors: Stefan Svensson
Original assignee: Katalysator Of Kronoberg AB
Current assignee: Katalysator Of Kronoberg AB
Priority date: 2024-07-03
Filing date: 2024-07-03
Publication date: 2026-01-07

Abstract

The present disclosure relates to a collision-yielding post assembly (1) comprising a lower hollow post element (5) carried by a base (11), an upper hollow post element (3) and a linkage assembly comprising an elastomeric retention linkage (7) fixedly connected to each of the lower (5) and upper (3) post elements. The elastomeric retention linkage (7) comprising an elastomeric insert (7) extending into each of the lower (5) post element and the upper (3) post element and a rigid sacrifice linkage (9) rigidly interconnecting the lower (5) and upper (3) post elements. The disclosure also relates to an elastomeric retention linkage (7, 70) for a post assembly (1) and a method (100) of enhancing the collision resistance of a signpost.

Description

Field of the invention

The present invention relates to a collision-yielding post assembly to be used for a traffic safe pole intended to support traffic signs, traffic lights, road lighting and the like.

Background

Several 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 bolt connection, a press-fit connection or a bonding connection or 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 accidentally collide with these poles. Conventionally, these poles are stiff and rigid, which implies that vehicles abrupt come to stop upon colliding with the pole. This may affect a 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. An example of such a collision-safe utility pole is a pole provided with a frangible tube section. The frangible tube section thus needs to be strong enough to carry the utility pole with the attached traffic sign or traffic light or road light but needs to break upon impact. It must withstand flexural stresses, for example, when a person leans against or climbs on or shakes the pole. It must also resist wind loads etc., be cheap to manufacture and require low cost to repair.
The frangible tube section can be designed in diverse ways, for example:
EP 2 014 850 discloses a lamp pole consisting of a column connected to a base, where the column and the base are disengaged upon impact by breaking a bolt-like connection and the column can be removed from the base.
It is an object of the present invention to provide a utility pole for traffic signs, lights etc with improved collision proofing and that is easy to replace.

Summary

It is an object of the present invention to solve, or at least mitigate, parts or all the above-mentioned problems. To this end, there is provided a collision-yielding post assembly comprising a lower hollow post element carried by a base; an upper hollow post element; and a linkage assembly comprising an elastomeric retention linkage fixedly connected to each of the lower and upper post elements. The elastomeric retention linkage comprising an elastomeric insert extending into each of the lower post element and the upper post element; and a rigid sacrifice linkage rigidly interconnecting the lower and upper post elements.
Upon collision with a vehicle, the rigid sacrifice link is deformed or breaks, while the lower post and base may remain stationary so as not to be displaced in the ground. Thereby, the need to dig a new base into the ground is obviated. Instead, the upper post element may be re-connected to the lower post element with a new linkage assembly. The rigid sacrifice linkage ascertains that the upper post element is not moved by wind load or other external forces which may be encountered during normal use. The elastomeric retention linkage ascertains that the upper post element is retained and not slung away by the collision, and may also serve to resiliently return the upper post element to an upright position such that the post may continue to temporarily serve until repaired or replaced. The arrangement of the elastomeric retention linkage inside the hollow upper and lower post elements provides protection against sabotage and sunlight, and enables the upper and lower post elements to be joined by a strong elastic element without any substantial exterior structures. The rigid sacrifice linkage may be made of e.g. steel or plastic. Typically, the upper and lower post elements may be made of metal, for example steel. The base may comprise a body of e.g. concrete or plastic configured to be anchored in the ground. The elastomeric insert may comprise insert ends extending into, and fixedly connected to, the respective upper and lower post elements.
Preferably, the rigid sacrifice linkage may be embedded in the elastomeric retention linkage.
Such an arrangement may facilitate replacement of the linkage assembly.
In one embodiment, each of the upper and lower post elements may be attached to the elastomeric retention linkage by a respective through fastener penetrating the insert and mutually opposing walls of the post elements.
Such a design enables an easy assembly and attachment when replacing the elastomeric retention linkage. According to embodiments, the through fastener may be a permanent through fastener. For example, the through fastener may be defined by an elongate rivet. Alternatively, the through fastener may be a releasable fastener, for example a threaded fastener.
Preferably, the elastomeric retention linkage may comprise a channel extending from the lower post element to the upper post element.
This enables electrical cables to extend from the lower post element to the upper post element via the insert. Such a post assembly is particularly well suited for e.g. traffic lights.
In one embodiment, the elastomeric retention linkage may comprise two or more insert elements which are separable from each other along the channel.
Such an arrangement facilitates positioning electrical cables in the channel without disconnecting the cables from one of the upper and lower posts.
Preferably, the elastomeric retention linkage may comprise a laterally extending flange separating the upper and lower post elements.
Such a flange counteracts damage to the meeting ends of the upper and lower post elements in the event of a collision. Moreover, the flange may serve as an axial end stop limiting the insertion depth of the respective insert ends of the elastomeric retention linkage into the respective post elements. According to embodiments, the outer contour of the flange may match the outer contour of the upper and lower post elements. Thereby, the flange does not define any substantial horizontal faces which may accumulate rain, which minimizes corrosion of the post assembly.
In one embodiment, the flange can separate the upper post element from the lower post element by less than 30 mm.
Such a flange thickness results in a highly limited compression range in the axial direction of the post elements. This relaxes the requirements on the sacrifice linkage's attachment to the upper and lower post elements. For example, fewer attachment points result in a sufficient rigidity of the interface between the upper and lower post elements.
Preferably, the upper post element can be attached to each of the rigid sacrifice linkage and the elastomeric retention linkage by an upper fastener, and/or the lower post element is attached to each of the rigid sacrifice linkage and the elastomeric retention linkage by a lower fastener.
The attachment of each respective post element to both the rigid sacrifice linkage and the elastomeric retention linkage using the same respective fastener simplifies assembly.
In one embodiment, the rigid sacrifice linkage may be attached at respective outside faces of the upper and lower post elements.
Thereby, a maximum rigidity may be obtained for the minimum of mechanical breaking strength. Moreover, the rigid sacrifice linkage may easily be replaced after minor collisions not causing damage to the elastomeric retention linkage. Still further, the rigid sacrifice linkage may be easily inspected for damage.
Preferably, the base may be buried in the ground, and an upper end of the lower post element is above ground.
This facilitates replacement of the linkage assembly. Preferably, the upper end of the lower post element is at least 5 cm above ground; such a position facilitates attaching the linkage assembly by one or more fasteners penetrating an outer wall of the lower post element from the outside. Preferably, the upper end of the lower post element is less than 20 cm above ground. Thereby, the torque generated by the impact of a collision, acting on the base, is minimized.
In one embodiment, the upper post element may carry a traffic sign.
As an alternative, the upper post element may carry a traffic light, or streetlights and the post may be arranged in the vicinity to busy roads and areas.
Preferably, the elastomeric retention linkage may comprise polyurethane.
Thanks to the relative stiffness of polyurethane, the elastomeric retention linkage contributes with further resistance against wind load and other external forces which may be encountered during normal use.
Preferably, the upper and/or the lower post element may have circular cylindrical shape. The post elements may also have other forms, such as rectangular or square shape.
In one embodiment, a horizontal cross-section of the upper and/or the lower post element can have a diameter of at least 60 mm. The outer diameter of the post element may be between 60-140 mm. The upper and lower post element can preferably have the same horizontal cross-section area but can however have different horizontal cross-section areas, where the cross-sectional area of the upper post element is smaller than the cross-sectional area of the lower post element.
In one embodiment, the ridged sacrifice linkage can comprise a horizontal cross-section area of at least 300 mm2. The rigid sacrifice linkage may be of steel, but other materials are possible such as plastic. The horizontal cross-section must have a dimension to withstand wind load and other external forces which may be encountered during normal use but needs to be deformed or break upon collision.
According to a second aspect, parts or all the above-mentioned problems are solved, or at least mitigated, by an elastomeric retention linkage for a post assembly comprising a hollow insert adapted to define a channel between an upper and a lower post element of the post assembly. The insert comprises two insert ends, arranged opposite to each other in the extension direction of the insert, adapted to be inserted in the respective post element of the post assembly, a lateral extending flange adapted to separate the post elements apart, and through holes adapted to each receive a mounting fastener penetrating the insert and mutually opposing walls of the post elements when the elastomeric retention linkage is connected to the post assembly.
The elastomeric retention linkage has the same advantages as described above regarding the collision-yielding post assembly. The insert ends are arranged opposite each other along the longitudinal extension direction of the tube. The insert ends may be chamfered to make the insert into to respective post element easier as well as abutment against the inside of respective post element. Each insert element can be provided with at least two through holes.
In one embodiment, the insert may consist of two identical, mirrored halves, which together form a unit. If the post assembly is to carry a traffic light or a streetlight, cables will be arranged within the post elements. During installation, and especially during replacement of the insert, the cable routing is facilitated if the insert consists of two parts that can be connected around the cables.
According to a third aspect, parts or all of the above mentioned problems are solved, or at least mitigated, by a method of collision-proofing a sign post, comprising the steps of: cutting the sign post into two post elements, an upper and a lower post element; providing each post element with through mounting holes on opposing walls; providing a rigid sacrifice linkage with corresponding mounting holes; inserting an elastomeric retention linkage according to claim 16 or 17 into the upper and lower post element until the flange separates the post elements apart; arranging the rigid sacrifice linkage at respective outside faces of the post elements; and inserting a through fastener into each through mounting hole from the outside for attachment of the post elements with the retention linkage and the rigid sacrifice linkage. According to this method is possible to amend an ordinary signpost into a collision proof signpost that acquires the same advantage as the collision-yielding posy assembly as described above.
It is noted that embodiments of the invention may be embodied by all combinations of features recited in the claims. Further, it will be appreciated that the various embodiments described for the device are all combinable with the method as defined in accordance with the second aspect of the present invention, and vice versa.

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and nonlimiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein:

Fig. 1 illustrates a schematic view of a collision-yielding post assembly according to a first aspect of the invention in unassembled state;
Fig. 2 illustrates a schematic view of a ground foundation of the collision-yielding post assembly according to Fig. 1;
Fig. 3 illustrates a schematic view of an elastomeric retention linkage of the collision-yielding post assembly according to Fig. 1;
Fig. 4 illustrates a schematic view of a rigid sacrifice linkage of the collision-yielding post assembly according to Fig. 1;
Fig 5. Illustrates a schematic view of the collision-yielding post assembly of Fig.1 in assembled state; and
Fig. 6 illustrates a schematic view of a second embodiment of the elastomeric retention linkage of the collision-yielding assembly according to Fig. 1;
Fig. 7 illustrates a schematic view of a method according to a third aspect of the invention.

All the figures are schematic, not necessarily to scale, and only show parts which are necessary to elucidate the embodiments, wherein other parts may be omitted.

Detailed description of the exemplary embodiments

Fig. 1 illustrates all constituent parts of a collision-yielding post assembly 1 according to a first aspect of the invention. The assembly 1 comprises an upper 3 and a lower 5 post element, an elastomeric retention linkage 7, a rigid sacrifice linkage 9 and a base 11 to carry the lower post element 5.
In the embodiment shown, the upper 3 and lower 5 post elements, each is hollow and has a circular cylindrical shape. The material of the post elements is preferably galvanized steel or aluminium to be corrosion resistant but could be for example a plastic material. A horizontal cross-section of each of the post elements has a diameter of between 60 - 140 mm and a wall thickness of 4 mm. In the embodiment shown, the upper 3 and the lower 5 post elements have a cross-section with the same diameter, but the upper post element 3 can be narrower compared to the lower post element 5. The post elements 3, 5 can have other shapes than circular cylindrical shape, such as rectangular, square or elliptical shape.
The upper post element 3 is significant longer than the lower post element 5, and preferably has a length of 1-3 m. The upper post element 3 has an upper end portion 13 and a lower end portion 15, arranged opposite to each other along the extension direction of the post assembly 1. The lower end portion 15 is adapted to be fixedly connected with the lower post element 5 through the elastomeric retention linkage 7 and the rigid sacrifice linkage 9 as will be discussed below. The upper end portion 13 may be covered by a lid to avoid that water enters inside the post element 3. Instead of a lid can a street light assembly be connected to the upper end portion 13. A traffic light and/or traffic and information signs may be attached to the upper post element 3 at different hights above the ground.
The lower post element 5 is significant shorter than the upper post element 3 and has a length of 20-40 cm. The lower post element 5 has an upper end portion 17 and a lower end portion 19, arranged opposite to each other along the extension direction of the post assembly 1. The upper end portion 17 is adapted to be fixedly connected with the upper post element 3 through the elastomeric retention linkage 7 and the rigid sacrifice linkage 9 as will be discussed below. The lower end portion 19 is connected to the base 11.
The base 11, illustrated in Fig. 2, may comprise a body of for example steel, concrete or plastic configured to be anchored in the ground. In the embodiment according to Fig. 2, the base 11 comprises a body of recycled plastic and is equipped with wing-shaped parts 21 to prevent that the base 11 turns within the ground when loaded. The base 11 has an upper end portion 23 and a lower end portion 25, arranged opposite to each other along the extension direction of the base 11. The lower end portion 25 is provided with a plate 27 for the base 11 to stand firmly within the ground. The lower end portion19 of the lower post element 5 is attached to the upper end portion 23 of the base 11 by a clamping arrangement. The connection between the lower post element 5 and the base 11 could also be a bolt connection or a bonding connection. When the lower post element 5 is attached to the base 11, the upper end portion 17 of the lower post element 5 is arranged less than 20 cm above ground but at least 5 cm above ground. The connection between the base 11 and the lower post element 5 may be protected by a seal hood 28. In the embodiment of Fig. 2, the seal hood 28 is a square shaped lid with walls arranged above ground and is adapted to abut the ground to prevent that water, chemicals, dog urine and other dirt comes in contact with the connection between the lower post element 5 and the base 11 and cables that may run within the post assembly 1, but other solutions are possible.
The elastomeric retention linkage 7, according to a first embodiment, is illustrated in Fig. 3. The elastomeric retention linkage 7 is defined by an elastomeric insert 7. The insert 7 has the same shape as the post elements 3, 5 but is 1-3 mm narrower than inner diameter of the the post elements 3, 5 and is adapted to abut the respective inside walls of the post elements 3, 5 when attached. The insert 7 is hollow and forms a channel 29 between the post elements 3, 5, when attached. A laterally extending flange 31 is arranged on the outside of the insert 7, around its circumference. The insert 7 may comprise two or more insert elements, which are separable from each other along the channel 29. In the embodiment shown, the insert 7 comprises one insert element, and the flange 31 is continuous. The flange 31 could also consist of several portions, evenly distributed around the circumference of the insert 7. The flange 31 has thickness of 1 to 3 mm above the insert 7. The insert 7 has an upper end 33 and a lower end 35. These ends 33, 35 have chamfered edges and are adapted to the inserted into the respective upper 3 and lower 5 post elements and abut the respective insides of the post elements 3, 5 when attached. When the insert 7 is arranged in the respective upper 3 and lower 5 post elements, the flange 31 will define an axial end stop limiting the insertion depth. The flange 31 has thus as large horizontal cross-section as the respective post elements 3, 5. The insert 7 is preferably made by polyurethane due to its stiffness properties, but other materials are possible.
In the embodiment shown in Fig. 1, the linkage 9 is provided by two rigid, rectangular plates 9a, 9b but other solutions are possible. One of the plates 9a is shown more clearly in Fig 4. The plates 9a, 9b are preferably made from a steel sheet but could also be formed from a plastic material. Each plate 9a, 9b is identical and has a horizontal cross-section area of at least 300 mm2 The plates 9a, 9b are adapted to be arranged on the outsides of the lower 5 and upper post elements and are each provided with through holes 37, 39, for connecting the post elements 3, 5, the elastomeric retention linkage 7 and the rigid sacrifice linkage 9 with each other by introducing a through fastener into each through hole 37, 39.
Fig. 5 illustrates the collision-yielding post assembly 1 in an assembled state. The elastomeric insert 7 has been introduced into the respective upper 3 and lower 5 post elements, the rigid plates 9a, 9b has been on arranged on mutually opposite sides of the post elements 3, 5. The post elements 3, 5, the elastomeric insert 7 and the rigid plates 9a, 9b have been provided with respective, mutually upper and lower through hole 37, 39. A respective fastener 41 has been arranged in these through holes 37, 39 for to attach the upper 3 and the lower 5 post elements with both the elastomeric insert 7 and the rigid plates 9a, 9b. A traffic light 43 has been attached to the upper end 13 of the upper post element 3. Since the post elements 3, 5, the elastomeric insert 7 and the base 11 are hollow, there is provided a channel through the entire assembly 1, which makes it suitable for cable routing through the assembly 1 down into the ground when the base 11 has been anchored within the ground.
At a collision with the collision-yielding post assembly 1, the rigid sacrifice linkage 9a, 9b is arranged to break while the elastomeric retention linkage 7 is arranged to ascertain that the upper post element 3 is retained and not slung away by the collision and serve to resiliently return the upper post element 3 to a reasonably upright position such that the post assembly 1 can continue to temporarily serve until replaced.
The second aspect of the invention, an elastomeric retention linkage for a post assembly, can be deduced from the description of Figs, 1-5.
Fig. 6 is schematic illustration of a second embodiment of an elastomeric retention linkage 70. The linkage 70 is provided by two identical, mirrored halves 70a, 70b. The halves 70a, 70b are adapted to be arranged around a cable arrangement that runs within the post assembly 1. This second embodiment is preferably used when transferring an ordinary post assembly for a traffic light or a streetlight into a collision-yielding post assembly according to the method described below.
Fig. 7 illustrates a method 100 of collision-proofing a signpost according to a third aspect of the invention.
The method comprises the following steps:

cutting 110 the signpost into two post elements, an upper 3 and a lower 5 post element;
providing 12 each post element 3, 5 with through mounting holes 37, 39;
providing 130 a rigid sacrifice linkage 9a, 9b with corresponding mounting holes 37, 39;
inserting 140 an elastomeric retention linkage 7 according to claims 16 or 17 into the upper and lower post elements 3,5 until the flange 31 separates the post elements 3, 5;
arranging 150 the rigid sacrifice linkages 9a, 9b at respective outside faces of the post elements 3, 5; and
inserting 160 a through fastener 41 into each through mounting holes 37, 39 for connection of the post elements 3, 5 with the elastomeric retention linkage 7 and the rigid sacrifice linkage 9a, 9b.

By this method it can collision-proofing an existing signpost so that it obtains the same advantages as the collision-yielding post assembly discussed above.
The invention has been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.
In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

Claims

A collision-yielding post assembly (1) comprising
a lower hollow post element (5) carried by a base (11);

an upper hollow post element (3); and

a linkage assembly comprising

an elastomeric retention linkage (7) fixedly connected to each of the lower (5) and upper (3) post elements, the elastomeric retention linkage (7) comprising an elastomeric insert (7) extending into each of the lower post element (5) and the upper post element (3); and

a rigid sacrifice linkage (9) rigidly interconnecting the lower (5) and upper post (3) elements.
The collision-yielding post assembly (1) according to claim 1, wherein the rigid sacrifice linkage (9) is embedded in the elastomeric retention linkage (7).
The collision-yielding post assembly (1) according to any of the preceding claims, wherein each of the upper (3) and lower (5) post elements is attached to the elastomeric retention linkage (7) by a respective through fastener penetrating the insert (7) and mutually opposing walls of the post elements (3, 5).
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the elastomeric retention linkage (7) comprises a channel (29) extending from the lower post element (5) to the upper post element (3).
The collision-yielding post assembly (1) according to claim 4, wherein the elastomeric retention linkage (7) comprises two or more insert elements which are separable from each other along the channel (29).
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the elastomeric retention linkage (7) comprises a laterally extending flange (31) separating the upper (3) and lower (5) post elements.
The collision-yielding post assembly (1) according to claim 6, wherein the flange (31) separates the upper post element (3) from the lower post element (5) by less than 30 mm.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the upper post element (3) is attached to each of the rigid sacrifice linkage (9) and the elastomeric retention linkage (7) by an upper fastener, and/or the lower post element (5) is attached to each of the rigid sacrifice linkage (9) and the elastomeric retention linkage (7) by a lower fastener.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the rigid sacrifice linkage (9) is attached at respective outside faces of the upper (3) and lower (5) post elements.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the base (11) is buried in the ground, and an upper end (17) of the lower post element (5) is above ground.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the upper post element (3) carries a traffic sign.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the elastomeric retention linkage (7) comprises polyurethane.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the upper (3) and/or the lower (5) post element has circular cylindrical shape.
The collision-yielding post assembly (1) according to claim 13, wherein a horizontal cross-section of the upper (3) and/or the lower (5) post element has a diameter of at least 60 mm.
The collision-yielding post assembly (1) according to any of the preceding claims, wherein the ridged sacrifice linkage (9) comprises a horizontal cross-section area of at least 300 mm2.
An elastomeric retention linkage (7) for a post assembly (1) comprising a hollow insert (7) adapted to define a channel (29) between an upper (3) and a lower (5) post element of the post assembly (1), wherein the insert (7) comprises
two insert ends (33, 35), arranged opposite to each other in the extension direction of the insert (7), adapted to be inserted in the respective post element (3, 5) of the post assembly (1),

a lateral extending flange (31) adapted to separate the post elements (3, 5) apart, and

through holes (37, 39) adapted to each receive a mounting fastener penetrating the insert (7) and mutually opposing walls of the post elements (3, 5) when the elastomeric retention linkage (7) is connected to the post assembly (1).

17. An elastomeric retention linkage (7) according to claim 16, wherein the insert (70) consists of two identical, mirrored halves (70a, 70b), which together forms a unit.

18. A method (100) of collision-proofing a signpost, comprising the steps of:
cutting (110) the signpost into two post elements, an upper (3) and a lower (5) post element;

providing (120) each post element (3, 5) with through mounting holes (37, 39) on opposing walls of each element (3, 5);

providing (130) a rigid sacrifice linkage (9) with corresponding mounting holes (37, 39)

inserting (140) an elastomeric retention linkage (7) according to claim 16 or 17 into the upper (3) and lower (5) post element until the flange (31) separates the post elements (3, 5) apart;

arranging (150) the rigid sacrifice linkage (9) at respective outside faces of the post elements (3, 5); and

inserting (160) a fastener into each through mounting hole (37, 39) from the outside for connection of the post elements (3, 5) with the elastomeric retention linkage (7) and the rigid sacrifice linkage (9).