Energy absorbing bollard

Abstract

An energy absorbing bollard comprising a post and a base is disclosed. The base defines a walled cavity to receive a base engaging end of the post and orient the post in an installed upright orientation. The base further comprises a lower energy absorbing region to absorb energy upon movement of the post, the lower energy absorbing region located between an inner wall of the walled cavity and a first outer surface portion of the base engaging end of the post and extending partway up the walled cavity; and an upper energy absorbing region to absorb energy upon movement of the post and having different energy absorbing characteristics to the lower energy absorbing region, the upper energy absorbing region located between the inner wall of the walled cavity and a second outer surface portion of the base engaging end of the post and positioned above the lower energy absorbing region.

Description

ENERGY ABSORBING BOLLARDPRIORITY DOCUMENTSThe present application claims priority from Australian Provisional Patent Application No. 2025900482 titled “ENERGY ABSORBING BOLLARD” and filed on 20 February 2025, the content of which is incorporated by reference in its entirety.TECHNICAL FIELD

[0001] The present disclosure relates to an energy absorbing bollard. In a particular form, the present disclosure relates to a bollard assembly suitable for inhibiting ingress of a moving vehicle into an area.BACKGROUND

[0002] Energy absorbing bollards are used for a variety of safety reasons, including inhibiting access by a vehicle into a restricted area or preventing ingress of a vehicle which may have lost control into an area requiring protection, eg, an area where the public or pedestrians may be at risk, such as a footpath, shopping strip, roadside dining area, or public transport stop. In another application, an energy absorbing bollard may provide a barrier that prevents a vehicle from striking a roadside hazard to protect the occupants of the vehicle.

[0003] Given these different requirements, compliance standards exist for bollards that are being used in a safety application. These will specify different conditions, such as vehicle speed and weight for impact testing. As an example, the Australian and New Zealand standard, AS / NZS 3845.2:2017, specifies three different vehicle speeds of 50 km / hr, 70 km / hr and 100 km / hr and two different vehicle weight classes of 1100 kg and 2270 kg for impact testing.

[0004] Typically, a given bollard configuration will be designed to meet one of these combinations of requirements (eg, a vehicle of 1100 kg travelling at 70 km / hr) and be certified accordingly. A bollard configuration that is designed to withstand a higher energy impact (eg, due to higher vehicle mass and / or speed), is likely to be too rigid and potentially cause more damage than necessary to a vehicle and its occupants due to the overly rapid deceleration of the vehicle, as compared to a bollard designed for a lower energy impact.

[0005] Unfortunately, this means that entities, such as road traffic authorities and the like, must source and maintain multiple different types of bollard configurations for the different types of expected impactsituations. It would be beneficial if a single bollard configuration could perform suitably over a range of different vehicle impact scenarios.SUMMARY

[0006] In one aspect, the present disclosure provides an energy absorbing bollard, comprisinga post; anda base defining a walled cavity to receive a base engaging end of the post and orient the post in an installed upright orientation, wherein the base further comprises:a lower energy absorbing region to absorb energy upon movement of the post, the lower energy absorbing region located between an inner wall of the walled cavity and a first outer surface portion of the base engaging end of the post and extending partway up the walled cavity; andan upper energy absorbing region to absorb energy upon movement of the post and having different energy absorbing characteristics to the lower energy absorbing region, the upper energy absorbing region located between the inner wall of the walled cavity and a second outer surface portion of the base engaging end of the post and positioned above the lower energy absorbing region.

[0007] In an aspect, an upper region deformation of the upper energy absorbing region is greater than a lower region deformation of the lower energy absorbing region, wherein the upper and lower region deformations result from absorbing energy transferred to the post from a vehicle impact.

[0008] In an aspect, the upper region deformation of the upper energy absorbing region is inelastic.

[0009] In an aspect, the upper energy absorbing region is replaceable following the upper region deformation of the upper energy absorbing region.

[0010] In an aspect, the lower region deformation of the lower energy absorbing region is elastic and is configured to maintain the post in the installed upright orientation.

[0011] In an aspect, the lower energy absorbing region is replaceable following a vehicle impact.

[0012] In an aspect, the post is replaceable following a vehicle impact.

[0013] In an aspect, wherein the post and walled cavity are substantially cylindrical in configuration.

[0014] In an aspect, the upper energy absorbing region is formed of a crushable material.

[0015] In an aspect, the crushable material is a metal foam.

[0016] In an aspect, the upper energy absorbing region has a compressive strength of about 50 MPa.

[0017] In an aspect, the upper energy absorbing region is configured as a collar member having a central aperture to receive the post, and sized and configured to seat within the walled cavity above the lower energy absorbing region.

[0018] In an aspect, the lower energy absorbing region is formed from an elastic material having an elongation limit.

[0019] In an aspect, an elongation limit percentage of the elastic material is about 500%.

[0020] In an aspect, the lower energy absorbing region is formed from a composite rubber material.

[0021] In an aspect, the lower energy absorbing region is configured as a sleeve member having a central aperture to receive the post, and sized and configured to seat within the walled cavity.

[0022] In an aspect, the base engaging end of the post is raised with respect to the base of the walled cavity to allow the post to rotate within the walled cavity upon vehicle impact without deformation.

[0023] In an aspect, the base comprises one or more bracing members extending outwardly from the walled cavity.

[0024] In an aspect, the base is installed in the ground.

[0025] In an aspect, the installed energy absorbing bollard is configured to withstand an impact of a vehicle with a mass of 2270 kg and a speed of 70 km / hr.

[0026] In another aspect, the present disclosure provides a base for an energy absorbing bollard, the base comprising a walled cavity to receive a base engaging end of a post and orient the post in an installed upright orientation, wherein the base further comprises:a lower energy absorbing region to absorb energy upon movement of the post, the lower energy absorbing region located between an inner wall of the walled cavity and a first outer surface portion of the base engaging end of the post and extending partway up the walled cavity; andan upper energy absorbing region to absorb energy upon movement of the post and having different energy absorbing characteristics to the lower energy absorbing region, the upper energy absorbing region located between the inner wall of the walled cavity and a second outer surface portion of the base engaging end of the post and positioned above the lower energy absorbing region.BRIEF DESCRIPTION OF DRAWINGS

[0027] Embodiments of the present disclosure will be discussed with reference to the accompanying drawings wherein:

[0028] FIG. 1A is a perspective view of an energy absorbing bollard according to some embodiments;

[0029] FIG. IB is an end on view of the energy absorbing bollard illustrated in FIG. 1A;

[0030] FIG. 1C is a side view of the energy absorbing bollard illustrated in FIG. 1A;

[0031] FIG. ID is a perspective view of the energy absorbing bollard illustrated in FIG. 1A as installed according to some embodiments;

[0032] FIG. 2A is a detailed perspective view of a base for an energy absorbing bollard according to some embodiments;

[0033] FIG. 2B is a top view of the base illustrated in FIG. 2A;

[0034] FIG. 2C is a side view of the base illustrated in FIG. 2A;

[0035] FIG. 3 A is a detailed perspective view of a lower energy absorbing region according to some embodiments;

[0036] FIG. 3B is a top view of the lower energy absorbing region illustrated in FIG. 3A;

[0037] FIG. 3C is a side view of the lower energy absorbing region illustrated in FIG. 3 A;

[0038] FIG. 4A is a detailed perspective view of an upper energy absorbing region according to some embodiments;

[0039] FIG. 4B is a top view of the upper energy absorbing region illustrated in FIG. 4A;

[0040] FIG. 4C is a side view of the upper energy absorbing region illustrated in FIG. 4A;

[0041] FIGS. 5A and 5B are front sectional views of an energy absorbing bollard according to some embodiments before and after vehicle impact; and

[0042] FIG. 6 is an aboveground energy bollard absorbing arrangement comprising in this example three energy absorbing bollards according to some embodiments.

[0043] In the following description, like reference characters designate like or corresponding parts throughout the figures.DESCRIPTION OF EMBODIMENTS

[0044] Referring now to FIGS. 1A-1C, there are shown various views of an energy absorbing bollard 100 according to some embodiments. In this example, energy absorbing bollard 100, comprises a post 110 and a base 140 that defines a walled cavity 145 to receive a base engaging end 111 of the post 110 and orient the post 110 in an installed upright orientation. The base 140 further comprises a lower energy absorbing region 160 to absorb energy upon movement of the post 110. The lower energy absorbing region 160 is located between an inner wall 146 of the cavity and a first outer surface portion 112 of the base engaging end 111 of the post 110 and extending partway up the cavity 145.

[0045] The base 140 further comprises an upper energy absorbing region 180 to absorb energy upon movement of the post 110 and having different energy absorbing characteristics to the lower energy absorbing region 160. The upper energy absorbing region 180 is located between the inner wall 146 of the cavity 145 and a second outer surface portion (not shown) of the base engaging end 111 of the post 110 and positioned above the lower energy absorbing region 160. In various examples, and as shown in FIGS. 1A and IB, the base is designed to be installed in the ground 105 so that the upper edge of the cavity 145 is approximately level with ground level 101. In some examples, there may be up to 100 mm of additional substrate material such as pavement, bitumen, or concrete extending upwardly from the upper edge of cavity 145 for aesthetic purposes to match the surrounding ambient environment design.

[0046] By employing two different energy absorbing regions 160, 180 disposed between the inner wall 146 of the cavity 145 and the post 110, this allows the energy absorbing bollard 100 to be configured to react appropriately for different impact circumstances.

[0047] Referring now to FIG. ID, there is shown a perspective view of the energy absorbing bollard 100 illustrated in FIG. 1A as installed in the ground 105. In one example, the installation process comprises excavating a rectangular shaped cavity (eg, dimensions of 2.2 m (length) x 1.4 m (width) x 0.5 m (depth) for a single -unit installation and which can be extended accordingly for a multi -unit installation). The process then comprises covering the bed and walls of the excavation area with a concrete moisture barrier (film / plastic) and then placing the energy absorbing bollard 100 centrally in the excavated area. Reinforcing rebars and ligatures 149 are then assembled to further support the base 140 of the energy absorbing bollard 100. Following assembly, concrete is poured into the excavated area. In one example, 40 MPa concrete (max 30mm aggregate) is employed, which is simultaneously vibrated (using a concrete vibrator) during pouring to remove air pockets, to form the concrete footing encompassing the base 140. The concrete footing is then levelled to create a level and even surface, ensuring proper drainage and structural stability.

[0048] An example of a multiple bollard installation is shown in the inset of FIG. ID which depicts two roads 181 separated by a median strip 183 and where vehicles 182 are driving in opposite directions. As can be seen by inspection, the configuration of the installed base depends on where the energy absorbing bollard 100 is located with respect to the direction of vehicle movement. As an example, energy absorbing bollards installed in the median strip, and which may be subject to impacts from both directions, include installed channel sections that extend both forward and backwards with respect to the post (see below).

[0049] Referring now to FIGS. 2A-2C, there are shown various views of the base 140 for the energy absorbing bollard 100 according to some embodiments. Base 140 is generally comprised of a support structure 141 for supporting the walled cavity 145 in a substantially vertical orientation to receive the base engaging end 111 of post 110. In this example, walled cavity 145 is formed from a cylindrical pipe section that extends upwardly from a rectangular base plate member 143 forming a floor base for the walled cavity 145 to a reinforcing top plate 144 having a circular cutout corresponding to the cross-sectional dimensions of walled cavity 145. Support structure 141 further comprises two parallel flange channel sections 147 attached to opposed sides of walled cavity 145 and extending outwardly from walled cavity 145 and, in this example, both forwards and backwards with respect to the upright orientation of walled cavity 145. Channel sections 147 function as bracing or anchor members when the base 140 is buried in the ground.

[0050] As would be appreciated, while in this example the channel sections 147 extend further in one direction with respect to walled cavity 145 (eg, backwards as depicted in FIG. 2A), in other examples separate channel sections or anchor members can extend in multiple directions with respect to walled cavity 145. As a non-limiting example, multiple anchor members could extend radially from walled cavity 145 forming a hub and spoke configuration.

[0051] Support structure 141 further comprises additional ribbing or reinforcement members 148 which function to assist in maintaining the walled cavity 145 in an upright configuration during any vehicle impact so as to provide a stationary rigid surface that does not substantially move when the post 110 is impacted by a vehicle.

[0052] As referred to above, in this example walled cavity 145 is substantially cylindrical, which matches the configuration of post 110. In other examples, the post 110 may not be of a cylindrical configuration and, in these examples, the walled cavity 145 may be sized and configured to match the post configuration. As an example, one or both of the walled cavity and the post may have a multi-sided or polygonal cross section (eg, such as hexagonal or octagonal).

[0053] In this example, as shown in FIGS. 2A-2C, walled cavity 145 further comprises an abutment member 150, which functions to ensure the base engaging end 111 of post 110 is not fully received in walled cavity 145 and there is a vertical distance or offset between the bottom of the post 110 and the baseof the walled cavity 145. This functions to raise the post 110 by a vertical distance with respect to the base of the walled cavity 145. In this example, abutment member 150 comprises an annular shelf or ledge extending inwardly from the inner wall 146 of cavity 145 which abuts against the end of the post 110 and includes a central aperture that allows the post to tilt with respect to the walled cavity 145.

[0054] In this manner, the post 110 may rotate within the walled cavity 145 upon vehicle impact in a region defined by a virtual cone defined by the walled cavity 145 which in turn determines the maximum deformation zone of both the lower and upper energy absorbing zones. This maximum deformation zone, comprising an inverted cone geometry defines the effective maximum tilt angle of the post that is available for deceleration when an errant vehicle hits the bollard post (see also FIG. 5B).

[0055] In various examples, the components of the base are formed from a suitable rigid and formable material, such as Grade 250 mild steel, which may be treated to enhance corrosion resistance, and where the components may be welded together. In various examples, the combined weight of the base 140 may be approximately 150 kg.

[0056] Referring now to FIGS. 3A-3C, there are shown various views of a lower energy absorbing member 300 which in some examples may comprise the lower energy absorbing region 160 shown in FIGS. 1A-1C.

[0057] In this example, lower energy absorbing member 300 is configured as an annular cylindrical sleeve member having an outer surface 310 sized and configured to seat within walled cavity 145 and having a central aperture 320 sized and configured to receive post 110. In this manner, lower sleeve member forms a lower energy absorbing region that is located between the inner wall 146 of the cavity 145 and an outer surface portion of the base of post 110.

[0058] In various examples, sleeve member 300 may be configured to receive a post having a non-cylindrical configuration but function as an adaptor to allow the non -cylindrical post to be received within a cylindrical walled cavity. In another example, sleeve member 300 may be configured to be received within a non-cylindrical walled cavity but be sized and shaped to receive a cylindrical post.

[0059] In one example, the lower energy absorbing region, and in this example the lower energy absorbing sleeve member 300, is configured to undergo a lower region deformation resulting from energy being transferred to the post 110 by a vehicle impact. In one example, the lower region is configured to maintain the post 110 in the installed upright orientation following a vehicle impacting the post.

[0060] In one example, the lower energy absorbing region or cylindrical sleeve member 300 is configured to have an elongation limit percentage selected from one of the following ranges including, but not limitedto: less than 400%, 400 - 450%, 450 - 500%, 500 - 550%, or greater than 550%. In one example, the elongation limit percentage is about 500 %. Throughout this specification, the term "about" means plus or minus 5% from a specified amount. For example, "about 10" refers to 9.5 to 10.5. A ratio of "about 5:1" refers to a ratio from 4.75: 1 to 5.25: 1.

[0061] In one example, lower energy absorbing region or cylindrical sleeve member 300 is formed of a composite rubber material comprised of 60% natural rubber and 30% carbon additives plus additional textile material and chemical additives. In this example, cylindrical sleeve member 300 has a tensile strength of 20 MPa, an elongation limit percentage of 520% and a Poisson's ratio of 0.5.

[0062] In one example, the lower energy absorbing region or sleeve member 300 is replaceable following a vehicle impact.

[0063] In various examples, lower energy absorbing region or cylindrical sleeve member may be selected from one or a combination of the following materials including, but not limited to; elastomers (eg, silicone, polyurethane, EPM), thermoplastic elastomers (TPE) (eg, thermoplastic polyurethane, styrene-butadiene-styrene), soft hydrogels, biopolymers (eg, based on spider silk), collagen-based substances, or high ductile metals and alloys.

[0064] In other examples, the lower energy absorbing region may be formed by inserting the post into the walled cavity and introducing a suitable resin in substantially liquid form (eg, thermoplastic polyurethane and allowing it to partway fill up the cavity 145 and be allowed to set.

[0065] Referring now to FIGS. 4A-4C, there are shown various views of an upper energy absorbing member 400 which in some examples may comprise the upper energy absorbing region 180 shown in FIGS .1A-1C.

[0066] In this example, upper energy absorbing member 400 is configured as an annular cylindrical collar member having an outer surface 410 (shown with a smooth outer surface cylindrical layer in FIG. 4A) sized and configured to seat within walled cavity 145 and having a central aperture 420 sized and configured to receive post 110. In this manner, collar member forms an upper energy absorbing region that is located between the inner wall 146 of the cavity 145 and an outer surface portion of the base of post 110, which is positioned above the lower energy absorbing region 160 or, as an example, upper energy absorbing member 300 illustrated in FIGS. 3A-3C.

[0067] In various examples, collar member 400 may be configured to receive a post having a non-cylindrical configuration but function as an adaptor to allow the non-cylindrical post to be received withina cylindrical walled cavity. In another example, collar member 400 may be configured to be received within a non-cylindrical walled cavity but be sized and shaped to receive a cylindrical post.

[0068] In accordance with the present disclosure, upper energy absorbing region, and in this example the upper energy absorbing or collar member 400 is configured to have different energy absorption characteristics to the lower energy absorbing region.

[0069] In one example, the upper energy absorbing region 180, and in this example an upper region deformation of the upper energy absorbing member or collar 400 is greater than a lower region deformation of the lower energy absorbing region 160, wherein both these upper and lower region deformations result from absorbing energy transferred to the post from a vehicle impact.

[0070] In one example, the upper region deformation of upper energy absorbing region 180, and in this example the upper energy absorbing member or collar 400 is inelastic. In various examples, the upper region deformation results from a crumpling or crushing (ie, inelastic deformation) of the upper energy absorbing region 180.

[0071] In one example, the upper energy absorbing region or collar member 400 is configured to have a compressive strength selected from one of the following in ranges including, but not limited to: less than 2 MPa, 2 - 10 MPa, 10 - 20 MPa, 20 - 30 MPa, 30 - 40 MPa, 40 - 50 MPa, 50 - 60 MPa, or greater than 60 MPa. In one example, the compressive strength is about 50 MPa.

[0072] In one example, the upper energy absorbing region or member is replaceable following deformation. In this manner, an energy absorbing bollard in accordance with the present disclosure may be returned to its original condition following an impact that does not damage the post by, as an example, replacing the upper energy absorbing collar member 400 with a new collar member.

[0073] In one example, the upper energy absorbing region or collar member 400 is formed from a crushable material.

[0074] In one example, the crushable material is a metallic foam material. In one example, the metallic foam material is an aluminium foam having the mechanical and structural properties set out in TABLE 1 and having an irregular size distribution.TABLE 1Aluminium Foam Mechanical and Structural Properties

[0075] In various examples, upper energy absorbing region or collar member may be selected from one or a combination of the following materials including, but not limited to; other metallic foams (eg, steel, titanium or metal alloy), concrete (including fibre -reinforced concrete), ceramic composites, high-density polymer composites, metallic honeycomb structures (eg, aluminium, steel, titanium or metal alloy), or porous sintered materials (eg, sintered metals).

[0076] Referring back to FIGS. 1A-1C, energy absorbing bollard 100 also comprises a post 110 formed of a rigid material such as steel or the like. In one example, post 110 is formed from a high tensile alloy steel cylinder pipe section. In one example, the high tensile alloy steel is 20MnV6 which is a carbonmanganese steel micro alloyed with vanadium having the properties set out in TABLE 2.TABLE 220MnV6 Hollow Bar Mechanical Properties

[0077] In various examples, the post 110 is further treated to enhance corrosion resistance such as by hot dipped galvanising.

[0078] In one example, post 110 is approximately 1.5 m in length and has an outer diameter of 180 mm. In combination with a base 140 having a walled cavity 145 of approximately 0.5 m in length this implies a post height of approximately 1.0 m in length. In various examples, the post height will vary between approximately 1.0 m - 1.8 m in length.

[0079] Post 110 can also play a role in energy absorption, depending on the degree of impact. As an example, for a vehicle having a weight of over 2000 kg and a speed of 70 km / hr the bollard may absorb energy and bend inelastically. As would be appreciated, after such an impact, while an area may have been protected from ingress of a moving vehicle, it is likely that the entire bollard will require replacement.

[0080] Referring now to FIGS. 5 A and 5B, there are shown front sectional views of an energy absorbing bollard 500 according to some embodiments before and after a vehicle impact. As depicted, a vehicle (not shown) impacting an energy absorbing bollard 500 in accordance with the present disclosure will do so with a certain mass and speed imparting a force and energy to the post 510 at a location above the ground 101 causing the post to move laterally or deflect from the installed upright position. In accordance with the present disclosure, the base 540 comprising the walled cavity will comprise a lower and an upper energy absorbing regions 560, 580 having different energy absorbing characteristics.

[0081] In one example, an upper region deformation 583 of the upper energy absorbing region 580 is greater than a lower region deformation 563 of the lower energy absorbing region 560 where both the upper and lower region deformations 583, 563 result from absorbing energy transferred to the post from a vehicle impact. As can be seen, there will be greater lateral movement of post 510 in the upper energy absorbing region 580 compared to the lower energy absorbing region 560 due to the orientation and configuration of the post with respect to the walled cavity 545 as post 510 rotates.

[0082] As discussed previously, the upper region deformation 583 of the upper energy absorbing region 580 is inelastic by the selection of a suitable material. In this example, the upper energy absorbing region 580 may inelastically deform and following the impact (and depending on the amount of damage) this region may simply be replaced. In various examples, the lower region deformation 563 of the lower energy absorbing region is elastic and is configured to maintain the post in the installed upright orientation (as indicated by arrows).

[0083] An energy absorbing bollard in accordance with the present disclosure may be optimised, as an example, for controlled deformation and effective energy dissipation of impact energy from a vehicle with a gross kerb mass of up to 2270 kg travelling at speeds of up to 70 km / hr but beneficially still provide a suitable bollard for lower energy impacts.

[0084] As would be appreciated, for increasing energy of vehicle impact it may only be necessary to replace the upper energy absorbing region after it has inelastically deformed. As the energy of vehicle impact increases, it may be necessary to replace both the upper energy absorbing region and lower energy absorbing region if it has gone beyond its elastic limit. For a vehicle impact of very high energy, the post may also deform or bend and require replacement.

[0085] In each of the above cases, the same bollard functions to provide its proper function and further allow the bollard to be restored to its original state by replacing one or more components. As would be appreciated, only a single bollard design in accordance with the present disclosure may be adopted to satisfy a large range of expected vehicle impact scenarios.

[0086] Referring now to FIG. 6, there is shown an aboveground energy absorbing bollard arrangement 600 comprising in this example three energy absorbing bollards according to some embodiments. In this example, and similar to energy absorbing bollard 100, each bollard comprises a base 640 that defines a respective walled cavity 645 that each receive a post 610. In this example, the base 640 comprises a metal plate or similar and the walled cavities 645 are attached and extend upwardly from the metal plate.

[0087] In accordance with the present disclosure, each walled cavity 645 further comprises a lower energy absorbing region (not shown) to absorb energy upon movement that extends partway up the walled cavity 645 and an upper energy absorbing region 680 having different energy absorbing characteristics to the lower energy absorbing region. In this example, the energy absorbing bollard arrangement 600 are spaced closer together (eg, 400 mm to 1000 mm) and can effectively withstand the same impact energies as larger single bollard installations.

[0088] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that such prior art forms part of the common general knowledge.

[0089] It will be understood that the terms “comprise” and “include” and any of their derivatives (eg, comprises, comprising, includes, including) as used in this specification, and the claims that follow, is to be taken to be inclusive of features to which the term refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied.

[0090] In some cases, a single embodiment may, for succinctness and / or to assist in understanding the scope of the disclosure, combine multiple features. It is to be understood that in such a case, these multiple features may be provided separately (in separate embodiments), or in any other suitable combination. Alternatively, where separate features are described in separate embodiments, these separate features may be combined into a single embodiment unless otherwise stated or implied. This also applies to the claims which can be recombined in any combination. That is a claim may be amended to include a feature defined in any other claim. Further a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0091] It will be appreciated by those skilled in the art that the disclosure is not restricted in its use to the particular application or applications described. Neither is the present disclosure restricted in its preferred embodiment with regard to the particular elements and / or features described or depicted herein. It will be appreciated that the disclosure is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope as set forth and defined by the following claims.

Claims

CLAIMS1. An energy absorbing bollard, comprising:a post; anda base defining a walled cavity to receive a base engaging end of the post and orient the post in an installed upright orientation, wherein the base further comprises:a lower energy absorbing region to absorb energy upon movement of the post, the lower energy absorbing region located between an inner wall of the walled cavity and a first outer surface portion of the base engaging end of the post and extending partway up the walled cavity; andan upper energy absorbing region to absorb energy upon movement of the post and having different energy absorbing characteristics to the lower energy absorbing region, the upper energy absorbing region located between the inner wall of the walled cavity and a second outer surface portion of the base engaging end of the post and positioned above the lower energy absorbing region.

2. The energy absorbing bollard of claim 1, wherein an upper region deformation of the upper energy absorbing region is greater than a lower region deformation of the lower energy absorbing region, wherein the upper and lower region deformations result from absorbing energy transferred to the post from a vehicle impact.

3. The energy absorbing bollard of claim 2, wherein the upper region deformation of the upper energy absorbing region is inelastic.

4. The energy absorbing bollard of claim 3, wherein the upper energy absorbing region is replaceable following the upper region deformation of the upper energy absorbing region.

5. The energy absorbing bollard of any one of claims 2 to 4, wherein the lower region deformation of the lower energy absorbing region is elastic and is configured to maintain the post in the installed upright orientation.

6. The energy absorbing bollard of any one of claims 1 to 5, wherein the lower energy absorbing region is replaceable following a vehicle impact.

7. The energy absorbing bollard of any one of claims 1 to 6, wherein the post is replaceable following a vehicle impact.

8. The energy absorbing bollard of any one of claims 1 to 7, wherein the post and walled cavity are substantially cylindrical in configuration.

9. The energy absorbing bollard of any one of claims 1 to 8, wherein the upper energy absorbing region is formed of a crushable material.

10. The energy absorbing bollard of claim 9, wherein the crushable material is a metal foam.

11. The energy absorbing bollard of any one of claims 1 to 10, wherein the upper energy absorbing region has a compressive strength of about 50 MPa.

12. The energy absorbing bollard of any one of claims 1 to 11, wherein the upper energy absorbing region is configured as a collar member having a central aperture to receive the post, and sized and configured to seat within the walled cavity above the lower energy absorbing region.

13. The energy absorbing bollard of any one of claims 1 to 12, wherein the lower energy absorbing region is formed from an elastic material having an elongation limit.

14. The energy absorbing bollard of claim 13, wherein an elongation limit percentage of the elastic material is about 500%.

15. The energy absorbing bollard of any one of claims 1 to 14, wherein the lower energy absorbing region is formed from a composite rubber material.

16. The energy absorbing bollard of any one of claims 1 to 15, wherein the lower energy absorbing region is configured as a sleeve member having a central aperture to receive the post, and sized and configured to seat within the walled cavity.

17. The energy absorbing bollard of any one of the preceding claims, wherein the base engaging end of the post is raised with respect to the base of the walled cavity to allow the post to rotate within the walled cavity upon vehicle impact without deformation.

18. The energy absorbing bollard of any one of the preceding claims, wherein the base comprises one or more bracing members extending outwardly from the walled cavity.

19. The energy absorbing bollard of any one of the preceding claims, wherein the base is installed in the ground.

20. The installed energy absorbing bollard of claim 19, wherein the energy absorbing bollard is configured to withstand an impact of a vehicle with a mass of 2270 kg and a speed of 70 km / hr.

21. A base for an energy absorbing bollard, the base comprising a walled cavity to receive a base engaging end of a post and orient the post in an installed upright orientation, wherein the base further comprises:a lower energy absorbing region to absorb energy upon movement of the post, the lower energy absorbing region located between an inner wall of the walled cavity and a first outer surface portion of the base engaging end of the post and extending partway up the walled cavity; andan upper energy absorbing region to absorb energy upon movement of the post and having different energy absorbing characteristics to the lower energy absorbing region, the upper energy absorbing region located between the inner wall of the walled cavity and a second outer surface portion of the base engaging end of the post and positioned above the lower energy absorbing region.

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