A vehicle arrestor

Abstract

The invention is directed to a vehicle arrestor for catching and stopping a moving vehicle, comprising: a base member having an upwardly facing first surface for receiving the moving vehicle thereon and an opposing second surface for arranging in frictional engagement with a ground surface, the base member unconstrained to the ground surface; and an engagement member for engaging with the moving vehicle, the engagement member disposed on the first surface of the base member, wherein the base member and the engagement member are configured to engage with the moving vehicle, combining a mass of the moving vehicle with a mass of the arrestor to transfer momentum from the moving vehicle to the arrestor, and thereby decelerate the moving vehicle.

Description

A VEHICLE ARRESTORTECHNICAL FIELD

[0001] This invention relates to a vehicle arrestor.

[0002] More particularly, the invention relates to a portable vehicle arrestor system and a method for deploying same.

[0003] More particularly, the invention relates to a portable vehicle arrestor system with an attenuator.BACKGROUND

[0004] Traffic barriers, cones, attenuators and arrestors are used in a number of roadside scenarios to protect or section parts of the highway. The use scenarios typically fall into two categories: dynamic works; and stationary works.

[0005] Some works are temporary and extend over a fixed location and may endure for no more than a few hours, for example highway clearing after an accident or an emergency or a police traffic stop. In contrast, some works can be more long term, for example where building or constructions is going on along a highway and workers and equipment require protection from other road users, during working hours over days, months or even years. In addition, dynamic road works can occur where road markings are being applied to a highway in a continuous, advancing, fashion.

[0006] Where fixed barriers are to be implemented for long term works, there is a substantial investment cost to erecting the barriers prior to work commencing (and removing them after works), these costs are not recoverable / acceptable in situations where the barrier / s are only required for a short period and also do not work for mobile works.

[0007] For mobile works large truck and vehicle mounted barriers (also referred to as TMAs for the truck mounted version) were conceived. These TMAs can travel ahead of the oncoming traffic to provide a mobile crash barrier protection system for workers located on the highway. However, these TMAs are large trucks designed to absorb large amounts of kinetic energy from impacts with speeding vehicles. They are very costly in terms of both the capital andlabour costs, and as such have limited availability, requiring advance booking in most cities, and often not available at all in rural areas within Australia.

[0008] It would be desirable to provide an economical safety solution between mobile and long-term stationary works i.e. short-term stationary.

[0009] The present invention was conceived with these shortcomings in mind.SUMMARY OF THE INVENTION

[0010] In a first aspect, the invention provides a vehicle arrestor for catching and stopping a moving vehicle, comprising: a base member having an upwardly facing first surface for receiving the moving vehicle thereon and an opposing second surface for arranging in frictional engagement with a ground surface, the base member unconstrained to the ground surface; and an engagement member for engaging with the moving vehicle, the engagement member disposed on the first surface of the base member, wherein the base member and the engagement member are configured to engage with the moving vehicle, combining a mass of the moving vehicle with a mass of the arrestor to transfer momentum from the moving vehicle to the arrestor, and thereby decelerate the moving vehicle.

[0011] The arrestor is not constrained to the ground surface. As such, the arrestor is free to move in combination with the moving vehicle after engaging therewith, once the downwards force of the arrestor is overcome. The force (Newtons) to be overcome to urge the arrestor to move is equal to the mass (Kg) of the arrestor multiplied by gravity (m / s2). This allows the momentum of the moving vehicle to be at least partially transferred to the arrestor, at which time the moving vehicle and arrestor are free to move together, their combined mass decelerating the moving vehicle. This allows the arrestor according to the invention to catch and stop a moving vehicle without needing to be bolted or otherwise engaged with the ground surface or road. As such, the ground surface a.k.a. road is not damaged by the deployment of the arrestor and additional / remedial works to the road are avoided. Typically, an arrestor or TMA that is not bolted or otherwise constrained to the road is required to have significant mass, such that the kinetic energy of a moving vehicle is entirely dissipated by the sacrificial structures of the TMA. However, this makes traditional TMAs expensive to purchase / hire and heavy to haul and transport.

[0012] The speed at which the moving vehicle contacts the arrestor will determine how much energy is in the impact, and how much energy is to be dissipated to bring the moving vehicle to a stop. Any more than about 3-5km / h will result in activation of the vehicles bumper system and additional speed with result increasingly in the deformation of the moving vehicle. As the vehicle mounts the base member and impacts the engagement member, the vehicle mass and the mass of the arrestor become combined and kinetic energy from the moving vehicle is transferred to the arrestor, imparting a velocity thereto. The fictional engagement between the ground surface and the second surface of the base member assist with dissipating impact energy by virtue of friction and heat, as the arrestor moves along the ground surface in combination with the moving vehicle.

[0013] The vehicle arrestor may further comprise a support member in contact with the engagement member, the support member configured to resist deflection of the engagement member under load. The base member provides a leading edge at a front of the base member orientable towards the moving vehicle, wherein the engagement member for engaging with the moving vehicle is disposed on the first surface of the base member, spaced rearwardly from the leading edge. The leading edge may improve engagement with the ground surface. The leading edge may reduce debris from an impact being propelled under the base member. The leading edge may assist in guiding the moving vehicle towards the engagement member.

[0014] The arrestor is configured to "Catch and Slow". In a first phase "Attenuation phase" the arrestor is stationary, and the vehicle impacts the attenuator. In a second phase "Arrest phase" the vehicle impacts the arrestor, and as momentum is transferred from the vehicle to the arrestor, the arrestor transitions from stationary to dynamic dissipating energy via friction in the form of heat, and brining the combined vehicle and arrestor assembly to a halt.

[0015] The invention was conceived to catch and slow vehicles. This provides protection for assets, machinery and people working on highways, adjacent traffic and other dangers. The arrestor provides effective crashworthiness, without the need for additional vehicles or workers. Due to the portable nature and dimensions of the arrestor, it can be driven quickly and easily to the target location and rapidly deployed for as short or as long a time is needed. The arrestor does not require monitoring, and was conceived as a "drop & go" unit, once deployed the arrestor remains operational until stowed for transport and moved to a newtarget location for re-deployment. The arrestor can be hooked-up to a prime mover in some embodiments, and delivered to a worksite using normal roads and a ute (utility vehicle) or similar vehicle with towing capacity, no additional safety entourage is required. The arrestor can be stored in an accessible location where individual users can check-out and check-in the arrestor for as long or as short a time as a given job requires.

[0016] The methodology of Catch and Slow provides that, in the catch phase is the initial impact phase when the arrestor is static. The errant vehicle drives onto the base member of the arrestor, where the arrestor utilises the mass of the arrestor and the mass of the impacting vehicle. The slow phase: is when the arrestor becomes dynamic, using friction between the base member and the ground to dissipate the remaining kinetic energy from the errant vehicle.

[0017] In some embodiments, the engagement member of the arrestor may further comprise an attenuator. The attenuator may be removable. The attenuator may be replaceable. In some embodiments, the attenuator is engageable to a prime mover to transport the arrestor to a worksite. In some embodiments, the arrestor is deployed independently of the prime mover.

[0018] The attenuator may be a deformable barrier, the deformable barrier configured to deform on contact with the moving vehicle to better engage with the moving vehicle and dissipate kinetic energy through the deformation of the deformable barrier. The deformable barrier may be part of a replaceable cassette. The deformable barrier may comprise a honeycomb internal structure. The deformable barrier may comprise an outer layer. The deformable barrier may be formed from a plurality of modular units having differing deformation characteristics. After an impact the whole or a damaged section of the deformable barrier can be removed, repaired, or replaced in anticipation of a subsequent impact. In this manner the attenuator is maintained and continues to provide protection for workers and equipment located behind the arrestor, each time it is deployed.

[0019] In some embodiment of the arrestor, the deformable barrier is mounted to the engagement member. The deformable barrier may be mounted to a front portion of the rear bumper system. The deformable barrier may be mounted to a rear portion of the rear bumper system opposing the engagement barrier. In some embodiments a plurality of deformable barriers is engaged to the arrestor to provide energy absorption from high-speed impacts,where any one or more of the deformable barriers can be replaced if damaged during the impact.

[0020] In some embodiment, multiple deformable barriers may be included within the engagement member. In some embodiments a smaller deformable barrier toward the front of the arrestor and a larger deformable barrier towards a rear of the arrestor. The smaller deformable barrier may include a post within the engagement zone, to help catch the vehicle, and may further comprises a mean to engage with the larger deformable barrier as to two move closer to one another. As the smaller deformable barrier collapses, it is then designed to hit the larger deformable barrier. To enable this deformation mechanism, the collapsible tubes sitting above and below the rearmost, larges deformable barrier.

[0021] In some embodiments, the arrestor may further comprise a bumper system. The bumper system may be located towards the leading edge of the base member. The bumper system may be supported by at least one leg extending between the bumper system and the base member. The bumper system may be configured to support at least one of a lighting array, a registration plate, signage, and alert beacons.

[0022] In some embodiments, the engagement member may further comprise a series of collapsible tubes, extending between the bumper system and the engagement member and configured to deform under load. The tubes may be straight, extending between the bumper system and the engagement member. In some embodiments, the tubes may be curved or bowed between the bumper system and the engagement member. There may be an upper pair of tubes and a lower pair of tubes, the tubes oriented parallel to one another when viewed from in a side elevation. In some embodiment the tubes are oriented to diverge towards one another proximate the leading edge of the base member, when viewed in a side elevation. This configuration can increase the likelihood of engagement with the errant vehicle. This configuration may reduce the risk of ride down where the errant vehicle is diverted under the bumper system or under the tubes during the impact.

[0023] In some embodiment the collapsible tubes are tethered to the attenuator. The tethers may be in the form of a leash disposed within each tube and secured to the arrestor. A single leash may encircle the upper tubes and a second leash may encircle the lower tubes. The leashes ensure that the collapsible tubes remain attached to the arrestor during an impact,reducing and controlling the debris scattered on a highway after an impact and reducing potential for risk to other highway users.

[0024] In some embodiments, the tubes are mounted by sacrificial structures. These sacrificial structures may be in the form of a crash box formed from a plurality of top and side plates and an end plate for engaging the arrestor. The tubes may provide a mounting flange for engaging with the internal surfaces of the crash box, to retain end portions of the tube therein. The mounting flange may be welded to the crash box to retain the tubes therein. The mounting flange may comprise a frangible portion. The frangible portion may be a lesser material gauge that surrounding structure to allow the frangible portion to shear or tear in an impact, thereby allowing the tube to rotate and twist within the crash box, while retaining the tube in the crash box. This arrangement allows the tubes to continue to collapse and thereby dissipate kinetic energy while allowing them to break free of the mounting plate and rotate more freely.

[0025] In some embodiments, the leading edge of the engagement member may be turned downwardly towards the ground surface. In some embodiments the leading edge may be component manufactured separately and subsequently attached to the base member of the arrestor. The leading edge may be removable or replaceable. Manufacturing the leading edge as a separate component may assist in manufacturing the arrestor. In addition, the leading edge is contacted in all engagements with an errant vehicle and is therefore likely to sustain damage in most impacts. As such, the ability to replace this part independently of the base member is economical.

[0026] In some embodiments, the base member may comprise one or more reinforcing members. The reinforcing members may be arranged on the first surface of the base member. The reinforcing members may be arranged on the second surface of the base member. In some embodiments, the base member may comprise a plurality of friction increasing members.

[0027] The friction increasing members may be feet, selectively engageable with the base member to protrude from the second surface thereof toward the ground surface. The feet may be configured to provide a solid body having at least one fastener thereon for engaging with the base member, and a high friction surface or pad for contacting the ground surface. Thebase member may comprise a swage formed therein to stiffen the base member in a first direction.

[0028] In some embodiments the support member may comprises a 3D framework to channel kinetic energy away from the engagement members. The support member may be a roll cage structure. The support member may comprise a firewall located forward of the engagement member. The firewall separates the sacrificial structure forward of the support member from the permanent, solid structure rear of the engagement member. The firewall also provides a structural member for supporting and mounting other components of the arrestor.

[0029] The arrestor of the preset invention can be transported to the target location by a prime mover, such as a truck, utility vehicle or utility vehicle or ute, or flatbed but can also, in some embodiments, be connected to a truck, or ute, in the manner of a trailer. The chassis may be transportable or portable. In some embodiments, the chassis is self-powered, and can be used to transport the arrestor to the worksite independently of another vehicle (or prime mover).

[0030] The chassis may support ground engaging members configured to move between a deployed configuration and a stowed configuration. The ground engaging members may be a pair of wheels mounted to an axle and an actuator; the actuator mounted to the support member. The actuator may be in the form or struts or air bags or damping units. In this manner, the chassis of the arrestor can be raised for stowage and transportation and lowered to bring the base member into engagement with the ground for deployment. Integrating the chassis, wheels and lift mechanism into the arrestor eliminates the need for a prime moved and / or forklift and / or crane for transporting and deploying the arrestor. However, the arrestor is always disconnected from the prime mover when deployed.

[0031] The chassis of the arrestor may further comprise at least one of the following: a towing hitch for engaging with a prime mover; a container for transporting equipment; a spare wheel; n arrow board; a sub-frame for mounting the wheels and actuator to; and at least one warning beacon, having either visual or auditory alarms.

[0032] In one embodiment, the invention provides an arrestor for decelerating a moving vehicle, comprising: a planar friction member having a first (or friction) surface and an opposing second (or support) surface, the support surface supporting an engagement member configured to engage a moving vehicle, wherein the friction surface is disposed in direct contact with a ground surface, such that friction between the first surface and the ground surface resists movement of the friction member when impacted by the moving vehicle. The engagement member is configured to engage with the moving vehicle on contact therewith, such that a mass of the moving vehicle is combined with a mass of the arrestor propelling the combined vehicle and arrestor forward together and dissipating kinetic energy through heat generated between the first surface and the ground surface via friction. The engagement member can be a collapsible barrier, and / or a deformable barrier and / or an energy absorbing structure. The engagement member also configured to dissipate kinetic energy of the moving vehicle on impact therewith.

[0033] In a still further aspect, the invention provides a method for deploying a portable vehicle arrestor system, the method comprising the steps of: delivering the portable vehicle arrestor to the target location in a stowed configuration; orienting a base member of the arrestor on a ground surface such that a leading edge of the base member is directed towards a source of moving vehicles; lowering a base member of the vehicle arrestor to bring a lower (or friction) surface or the base member into frictional engagement with the ground surface. The portable vehicle arrestor system can comprise a vehicle arrestor configured for attachment with a prime mover. In some embodiments, the vehicle arrestor can be mounted to a chassis comprising a lifting mechanism allowing the vehicle arrestor to be stowed or deployed independently of a prime mover and negating the requirement for additional equipment such as trucks and forklifts for deploying the vehicle arrestor. In embodiments of the system using a vehicle arrestor configured for attachment to a prime mover, the method of deploying the portable vehicle arrestor system additionally includes the step of disengaging the prime mover from the vehicle arrestor. The vehicle arrestor mass has an impact on the working of the arrestor system and leaving the prime mover attached to the vehicle arrestor will unnecessarily increase the mass of the arrestor and risk damage to the prime mover. The mass of the arrestor and captured vehicle is combined in the event of an impact and depending on the amount ofkinetic energy to be dissipated to bring the vehicle to a stop, a velocity can be imparted to the arrestor.

[0034] In one embodiment, there is provided a method for deploying a vehicle arrestor system, the method comprising the steps of: (i) delivering the vehicle arrestor to the target location; (ii) positioning a base member of the arrestor above a ground surface at the target location such that a leading edge of the base member is directed towards a source of moving vehicles; and (iii) deploying the vehicle arrestor by placing the base member into frictional engagement with the ground surface.

[0035] The base member may be substantially planar and may include an upwardly facing first surface and opposing second surface in frictional engagement with the ground surface for receiving a moving vehicle thereon, and a support member in contact with the engagement member. The method may further comprise the step of supporting the engagement member to resist deflection thereof during impact with a moving vehicle.

[0036] In some embodiments, the step (i) delivering the portable vehicle arrestor uses a disengage able prime mover to transport the portable vehicle arrestor mounted to a chassis or trailer. Alternatively, in some embodiments, the step (i) delivering the portable vehicle arrestor uses a truck and / or forklift to transport the portable vehicle arrestor.

[0037] Various features, aspects, and advantages of the invention will become more apparent from the following description of embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Embodiments of the invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features in and described with reference to the accompanying drawing are illustrated by way of example, and not by way of limitation, of which:

[0039] Figure 1 is a schematic view of a vehicle arrestor according to one embodiment of the invention, illustrating a base member, an engagement member and a support member.

[0040] Figure 2 is a side perspective view of a vehicle arrestor according to another embodiment of the invention, illustrating a deformable member or attenuator cassette mounted to the engagement member of Figure 1.

[0041] Figure 3 is a perspective rear view of the vehicle arrestor of Figure 2, illustrating a vehicle aligned with the arrestor prior to impact therewith;

[0042] Figure 4 is a further embodiment of the arrestor having the same underlying architecture as the arrestors of Figures 1 to 3 and further comprising a bumper system and a series of deformable rails;

[0043] Figure 5A is a further embodiment of the arrestor of Figures 1-4 further comprising an additional deformable structure mounted to an inwardly facing surface of the bumper system in a deployed configuration with the base member in engagement with a ground surface;

[0044] Figure 5B is a front perspective view of the arrestor of Figure 5A in a stowed or transportable configuration for transportation to a work site;

[0045] Figure 5C is a front perspective view of another embodiment of an arrestor in accordance with the invention in a stowed or transportable configuration for transportation to a work site;

[0046] Figure 5D is a perspective view of an engagement member and deformable rails of the arrestor of Figure 5C, with a pair of deformable members opposing each other within the bounds of the deformable rails;

[0047] Figure 5E is a perspective of Figure 5D with the deformable members removed to better illustrate the deformable rails and mounting structures thereof;

[0048] Figure 5F illustrates an alternative tensioning member for the rear bumper assembly;

[0049] Figure 6A is an underside perspective of the arrestor of Figure 5, illustrating a series of feet for increasing frictional engagement with the ground surface;

[0050] Figure 6B is an enlarged underside view of Figure 6A, illustration a series of parallel spaced longitudinal members;

[0051] Figure 6C is an underside perspective of the arrestor of Figure 5C, illustrating a two- piece base member, a rearward portion of which comprises a series of stiffening swages;

[0052] Figure 7A is an isolated perspective view of a single foot member disconnected from the base member, illustrating attachment means;

[0053] Figure 7B is a perspective view of the foot of Figure 7A aligned for connection to the base member, illustrating a cross-sectional form and bevelled edges to the foot;

[0054] Figure 8 is a perspective view of the bumper system and deformable rails, illustrating crash boxes for engaging the deformable rails with a bumper beam of the bumper system;

[0055] Figure 9A is an enlarged perspective view of the crash box from Figure 8, illustrating a series of end plates, side plate and a mounting plate thereof;

[0056] Figure 9B is an enlarged perspective view of an end portion of a deformable rail with a rail end mounting plate attached;

[0057] Figure 10 is a perspective view of the engagement member and deformable rails, with an upper tube of the deformable rails displaced to reveal a restraining leash that extends therethrough;

[0058] Figure 11A is a perspective view of the crash box mounted to the engagement member, and encapsulating the end portion of the deformable tube and rail end mounting plate therein;

[0059] Figure 11 B is a perspective view of an attachment means for engaging the restraining leash to the engagement member within the crash box;

[0060] Figure 11C is a perspective view of a crash box, with the end plate removed, to illustrated a bolt extending through both the crash box and an end portion of the tube, to hold the tube within the crash box during the early stages of an impact;

[0061] Figure 12A is a side view of the deformable rails mounted to the engagement member, atop the base member;

[0062] Figure 12B is a top view of Figure 12A illustrating the bowed configuration of the deformable rails and a pair of longitudinal reinforcement rails that extend along the base member, under the deformable barrier and out to a trailing edge of the base member;

[0063] Figure 13 is a perspective view of the internal frameworks of the arrestor, the underside rails and cross-rails supporting the underside of the base member highlighted for contrast;

[0064] Figure 14 is a perspective view of the internal frameworks of the arrestor, a perimeter frame or firewall between the engagement member and the support member highlighted for contrast;

[0065] Figure 15 is a perspective view of the internal frameworks of the arrestor, a 3D framework of the support members highlighted for contrast;

[0066] Figure 16 is a perspective view of the internal frameworks of the arrestor, illustrating a subframe or chassis of the arrestor for mounting a deployment mechanism thereto, the subframe highlighted for contrast;

[0067] Figure 17A is a partial perspective view of the internal frameworks of the arrestor, illustrating the deployment mechanism for raising and lowering the base member relative to a ground surface highlighted for contrast;

[0068] Figure 17B is a perspective view of a suspension system and lifting system for raising and lowering the base member relative to the ground surface; and

[0069] Figure 18 is a perspective view of one embodiment of the arrestor stowed for transportation to a work site and hitched to a prime mover.

[0070] The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments, although not the only possible embodiments, of the invention are shown. The invention may be embodied in many different forms and should not be construed as being limited to the embodiments described below.DEFINITIONS

[0071] In the following description a "Road safety barrier system" is understood to refer to a physical barrier separating a work area and a travelled path, designed to resist penetration by an errant vehicle and as far as reasonably practicable, to redirect errant vehicles back into the travelled path.

[0072] In the following description a Truck Mounted Attenuator (TMA) is understood to refer to a safety device designed to reduce the severity of collision that can be fitted to slow moving or stationary trucks which are exposed to potential impact from behind any approaching traffic.

[0073] In the following description an Advance Warning Area (AWA) is understood to refer to an area in advance of a worksite where advance warning traffic control devices are erected to wand and inform of change to traffic conditions ahead and to five road user time to adjust their driving behaviour.

[0074] In the following description an Adjacent Clearance Area (ACA) is understood to refer to an area immediately adjacent to the traffic lane, and typically between the traffic land and the worksite that should be kept free from features what would be potentially hazardous to errant vehicles.

[0075] In the following description an arrow board is understood to refer to electronic signage boards for displaying traffic guidance or instructions. The arrow board is also sometimes referred to as an arrow sign in the industry.

[0076] In the following description a safety buffer is understood to refer to the unoccupied space between a warning area and a work area which allows for an errant vehicle to pull up before reaching the work area.DETAILED DESCRIPTION OF EMBODIMENTS

[0077] With particular reference to Figures 1 -18, there is illustrated a vehicle arrestor (100) for catching and stopping a moving vehicle (1), comprising: a base member (5) having an upwardly facing first surface (6) for receiving the moving vehicle (1) thereon and an opposing second surface (7) for arranging in frictional engagement with a ground surface (G), the base member (5) having a leading edge (9) at a front of the base member oriented towards the moving vehicle (1); an engagement member (10) for engaging with the moving vehicle (1), the engagement member disposed on the first surface of the base member (5) and spaced rearwardly from the leading edge (9); and a support member (15) in contact with the engagement member (10), the support member (15) configured to resist deflection under load, wherein the base member (5) and the engagement member (10) are configured toreceive and engage the moving vehicle (1) combining a mass of the moving vehicle (1) with a mass of the arrestor (100) to thereby decelerate the moving vehicle (1), and whereby the frictional engagement between the ground surface (G) and the second surface (7) of the base member (5) dissipates kinetic energy from the combined vehicle and arrestor assembly by means of friction.

[0078] Figure 1 is a schematic side view of the arrestor (100) according to a first embodiment, illustrating the engagement member (10) as a vertical face supported by the support member (15) and located centrally on the base member (5). The base member (5) is substantially planar maximising contact area between the lower, second surface (7) and the ground surface (G).

[0079] The arrestor (100) is deployed with the leading edge (9) oriented towards an oncoming vehicle (1) such that the vehicle mounts the base member (5) and is guided into contact with the engagement member (10). The engagement member (10) is rigid and supported by the support member (15) to stop the engagement member (10) from deforming or being deflected, thereby maintaining contact with the vehicle (1). As the vehicle (1) contact the rigid engagement member (10) the vehicle (1) begins to deform engaging with both the engagement member (10) and the base member (5) and combining the masses of the arrestor (100) and the vehicle (1).

[0080] According to the conservation of momentum: a collision occurring between two objects will have the same momentum before the collision as it will have after the collision. Therefore, the momentum lost by the first object will be equal to the momentum gained by the second object. According to Newton's third law, the impulses will be equal in magnitude and opposite in direction, such that for an inelastic collision: rriiUi + rri2U2 = (m, +rri2) vWhere ml is the mas of the vehicle, and u1 is the initial impact velocity. And m2 is the mass of the arrestor (100) and u2 is the initial velocity of the arrestor (100). V is the velocity after the collision where the mass of the vehicle and the mass of the arrestor have been combined.

[0081] In a vehicle impact scenario, the vehicle will have initial velocity (u1) while the arrestor will be stationary, therefore u2 = 0. For this case: rriiUi = (mi +rri2) v

[0082] The vehicle will have an initial velocity (ui) which contributes to the kinetic energy of the collision, as:Kinetic energy Ek = 2 (mi * U12)

[0083] In the impact scenario, the velocity of the combined arrestor (100) and vehicle (1) is greatly reduced as the mass of the two objects is combined. There will still be some residual velocity (v) and the arrestor (100) and combined vehicle (1) assembly may still be moved from the original deployment location within the safety buffer. The residual energy is dissipated as heat due to the friction between the second surface (7) of the engagement member and the ground surface (G) on which the arrestor (100) is located. In this manner the arrestor (100) operates as a sentinel, guarding and protecting workers at the work site from errant vehicles entering the work site at speed.

[0084] The embodiment of the arrestor illustrated in Figure 1, is designed for low-speed impacts; for example, MASH TL1 (50km / h). The arrestor (100) does not require any energy absorption characteristics, over and above that which vehicle (1) already provides. The simple engagement member (10) and support member (15) are formed as a horizontal floor plate, and a vertical impact plate located in the mid-section of the floor plate. The support member adjacent and rearward of the engagement member (10) in relation to the leading edge (9) essentially bracing the engagement member (10).

[0085] MASH is a basis for current crash testing protocols applied to safety barriers, administered by Ausroads in line with AZ / NZS 3845 with outlines the AASHTO Manual for Assessing Safety Hardware (MASH).

[0086] The recognised Australian and New Zealand MASH test level speeds include: Test Level 1 (TL1) 50 km / h; Test Level 2 (TL2) 70 km / h; and Test Level 3 (TL3) 100 km / h.

[0087] A further embodiment of the arrestor (101) is configured for mid-level speed impacts: for example, MASH TL2 (70km / h) and illustrated in Figure 2. The underlying structure of the arrestor (101) comprises the same features as the arrestor (100): a base member (5), an engagement member (10) and a support member (15), and an additional deformable member (20). The deformable member (20) can be an attenuator, a crash barrier, an energy absorbing member or the like. The deformable member (20) is mountedto the engagement member (10) and located between the leading edge (9) and the engagement member (10). As such, the support member (15) continues to support the engagement member (10) and the deformable member (20) and resists the engagement member (10) from deflecting during an impact. Deflection of the engagement member (10) would diminish the energy absorption capability of the vehicle itself, and could result in the vehicle not engaging with the arrestor (100) and bouncing or deflecting off the engagement member (10).

[0088] Figure 3 illustrates the arrestor (101) in alignment for receiving the vehicle (1). While the vehicle and arrestor are illustrated to have 100% overlap it is understood, that in reality the vehicle alignment with the arrestor (101) and engagement member (10) may be anywhere between 1 %-100%.

[0089] The deformable member (20) is a replaceable unit that can be easily removed from the engagement member (10). Once an impact has occurred the deformable member (20) will no longer provide good energy absorption as any deformable structures therein will have been expended during the impact. It is envisaged that a number of deformable barrier structures are available, some unitary, some formed from a plurality of blocks, each block having differing crush characteristics. In some forms the deformable member (20) can comprise a highly deformable honey-comb structure which dissipates energy well and also improves engagement with the front end structure of the oncoming vehicle (1) to improve adhesions. The deformable barrier (20) can have one or more casings to provide: cohesion of barrier sections, weather proofing, friction, engagement, visibility markings and designations of grade.

[0090] A still further embodiment of the invention is the arrestor (102) illustrated in Figure 4. Arrestor (102) further comprises additional attenuation structures (25) configured for high-level speed impacts: for example, MASH TL3 (100km / h). The additional attenuation structures (25) can comprise one or more combinations of a rear bumper system (26) and a series of deformable rails (27).

[0091] The rear bumper system (26) is mounted adjacent the leading edge (9) of the base member (5). The bumper system (26) provides at least one bumper beam (28) formed as a collapsible structure (illustrated in Figure 8) for absorbing energy in low-speed collisions. Inimpacts where the vehicle velocity is low, the bumper system (26) may be the only damaged component of the arrestor (102), for example in impacts between 5kph-10kph. As the vehicle impact speed increases, the damage to the arrestor (103) will increase, and there will be an increased likelihood that the bumper system and / or collapsible structure will need to be replaced or repaired.

[0092] The bumper system (26) is adjacent the leading edge (9) of the base member (10) and as such, when the stowed arrestor (103) is being transported, this area of the arrestor is visible to traffic. As such, a registration plate and appropriate lighting will be required to drive on highways, to ensure that trailing traffic has visibility of braking lights, indicating lights, and reversing lights.

[0093] As the bumper system (26) is elevated above the base member (5) to better align the bumper beam (28) with a median height of bumper systems of other road vehicles, a dampener is provided. The dampener is illustrated in Figure 4 as a pair of legs (29) that support the bumper system (26) against the base member (5) and take the weight thereof. This reduces vibration from the bumper system (26) during transportation of the arrestor and alleviates the risk of the bumper system (26) sagging and becoming misaligned with the engagement member (5).

[0094] Further contemplated but not illustrated in Figure 4, a secondary vehicle engagement feature can be mounted to the bumper system (26) to engage and adhere the vehicle to the bumper system (26) on contact therewith. Aside from engagement with the vehicle (1) the secondary vehicle engagement features can assist with Occupant Impact Velocity (OIV - is an occupant risk evaluation criteria under MASH, measuring the velocity at which a "point-mass" occupant model impacts internal surfaces of the vehicle's occupant compartment) and avoiding ride-down of the vehicle (where the front end of the vehicle dips under rapid deceleration, which can cause poor alignment or engagement with the bumper system (26) and in worst case scenarios a failure to engage.

[0095] A further component of the additional attenuation structures (25) is illustrated in Figure 4 as the series of deformable rails (27). The deformable rails (27) comprise four curved tubes (30), two upper tubes (30a) and two lower tubes (30b). The configuration,mounting and retention of these tubes (30) will be discussed in further detail in relation to Figures 8-11 herein.

[0096] The tubes (30) form a connection between the engagement member (10) and the bumper system (26). They extend between the engagement member (10) and bumper system (26) forming a bowed ring therebetween. Too straight, and there is a risk that the tubes (30) could punch through the adjoining structures under a high-speed collision: bowed, the tube (30) will be loaded during the impact, such that their deformation will provide a further means of dissipating kinetic energy from the crash. The step-up from TL2 (70km / h) to TL3 (100km / h) requires the system to manage approximately double the kinetic energy (as the energy component is derived from the square of the vehicle's velocity). As such, significantly more attenuation members are incorporated into arrestor (103) as compared with arrestors (102) and (101), albeit all arrestors share the same base architecture and three underlying components.

[0097] The upper tubes (30a) are mounted above the deformable member (20) to the engagement member (10), while the lower tubes (30b) are mounted below the deformable member (20) to the engagement member (10). As such, the deformable member (20) is not inhibited from engagement by virtue of the addition of the deformable rails (27).

[0098] The tubes (30) are open, rolled, sections and each is mounted to the respective engagement member (10) or bumper system (26) by crash boxes (35). These boxes (35) will be described in further detail in relation to Figures 9-11 herein. Each crash box (35) encapsulates an end portion (31) of one of the tubes (30) holding it in place and maintaining orientation of the tube (30). After an impact, the crash box (35) can be easily opened to release the tube (30) from within for ease of replacement. Each box (35) is made from a plurality of metal plates, and these can be replaced as and when signs of deformation become apparent.

[0099] In addition to the crash boxes (35) the tubes (30) are mounted about a pair of restraining leashes (38). An upper leash (38a) within the upper tubes (30a) and a lower leash (38b) within the lower tubes (30b). The leashes are formed from a steel cable, and bolted (or similar) at opposing ends to the bumper system (26) and the engagement member (10). Alternatively, a single upper leash can be mounted only to the engagement member (10) orbumper system (26), whereby the leash is threaded through either both upper tubes (30a) or both lower tubes (30b) forming a closed leash therein. The bolts or retaining members can be concealed within the tubes, within the crash boxes (35).

[0100] The leashes (38a, 38b) do not serve any purpose regarding energy absorption, instead they provide a redundancy system to mitigate the risk of debris. Even when any sections of the tubes (30) are pulled apart or disconnected from each other, the leash running through all sections keeps them together.

[0101] These retaining leashes ensure that under impact loading the deformation of any given tube (30) will not result in the tube being released from the respective crash box (35) and springing free of the arrestor (102). The tube (30) coming free would result in a diminished energy absorption capacity of the arrestor (103) and could further pose a risk of impalement if impacted by the vehicle.Attenuator Deformation Concept

[0102] It has become apparent with some barrier technologies on the market that smaller vehicles can "dive" underneath the attenuator and fail to engage with the safety structure adequately. This diving motion effectively wedges the impacting vehicle between the attenuator and the road instead of imparting kinetic energy into the attenuator to deform and collapse the energy absorbing structure. The result can then cause the attenuator to ride-up over the top of the vehicle bonnet. A key factor in this diving motion is a mismatch between a bumper height of the moving vehicle (e.g. lower vehicles such as sports cars) and the attenuator, and additionally a low centre of gravity which also encourages the diving motion under deceleration particularly where the vehicle centre of gravity is lower than the attenuator.

[0103] In view of the above, the inventor conceived of a concept based around a "bubble" idea whereby the point of impact exerts a lesser influence on the deformation of the arrestor because wherever the "bubble" or circular frame structure is impacted a similar result will occur. To develop this concept, focus was placed on location of the bumper system (26) and how the impact energy is channelled back into the energy absorbing structures (26, 30, 20, 33), and how it collapses inwardly to attenuate / absorb the kinetic energy as consistently as possible: regardless of the vehicle or the angle at which the arrestor (102) is impacted.

[0104] The following aspects of the arrestor (102) were developed to address the above issues: a) Alignment of upper tubes (30a) to the lower tubes (30b). As illustrated in Figure 12A the pair of upper tubes (30a) have a top-down alignment, while the lower tubes (30b) have a bottom-up alignment (not horizontal or aligned in parallel). This configuration aids in controlling the engagement and deformation of the deformable rails (27) to remain more centralised upon impact, directing energy outwardly towards the engagement member (10). This arrangement also allows the ends of the tubes (31) closest to the bumper system (26) to be closer together to maximise overlap height with vehicle bumper systems. b) Crash boxes (35) engagement with the tube ends (31). As referenced above, in addition to different size of vehicles there is also variability regarding the angle at which a vehicle may impact the bumper system (26). To help address impact overlap issues, the inventor looked for a more flexible connection between the tubes (30), the bumper system (26) and the trailer chassis (50). The crash boxes (35) proved to be surprisingly effective during crash testing whereby each tube end (31) is encapsulated within a respective crush box (35), and a fracture point is engineered into the connection to allow the tube ends (31) to partially disconnect from the crash box (35) during impact but remaining therein, allowing the tube ends (31) to rotate, twist, etc. and deform within the crash box (35) in a controlled manner. This is discussed in further details in relation to Figures 9A, 9B and 11 herein. c) Bumper system support legs (29). As the arrestor (100,101,102) incorporates the base member (5) for catching the impacting vehicle, the inventor conceived of configuring the legs (29) to provide additional engagement structures, thereby helping to catch smaller vehicles and protect against diving of the vehicle between the deformable rails (27) and base member (5). This provides increased accommodation for a range of different vehicles and impact angles as commonly seen in the mix of vehicles on roads of today.

[0105] A still further embodiment of the invention is the arrestor (103) illustrated in Figures 5A and 5B. Arrestor (103) further comprises an additional or second deformable member (21)configured for higher-level speed impacts: for example, MASH TL3 (100km / h) and above. The second deformable member (21) is mounted to a rear face of the bumper system (26) and faces the first deformable member (20). Like deformable member (20) the additional deformable member (21) can be a replaceable barrier, a honeycomb barrier, or a tailored barrier.

[0106] Surrounding the first deformable member (20) is a support (24). The support (24) is illustrated as surrounding the perimeter of the deformable member (20) entirely in Figures 5A- 5D, however, it can also be configured to only partially surround the deformable member (20). The support (24) is mounted to the engagement member (10). The outer surface of the deformable member (20) can also be wrapped with a thinner, cover layer of aluminium (for example between 1 mm-2mm) to assist in containing the internal honeycomb structure of the deformable member (20) therein during an impact. Similar supports and wrapping can be provided on one or more of the other deformable members (21, 22), although not shown in the Figures.

[0107] The support (24) can be made from a resilient material, for example steel or aluminium. In one embodiment the aluminium material is about 4mm in gauge to provide a base of the first deformable member (20) with support and stability. This can prevent the deformable barrier from slipping, delaminating or losing connection to the engagement member (10) during a high-speed impact. The support (24) also provides support and stability to the deformable member (20) when being transported and subject to vibrational forces caused by road inputs.

[0108] The additional deformable member (21) is mounted between the upper and lower tubes (30a, 30b) and does not hamper the tubes' ability to absorb impact energy during a crash. As the tubes deform, the additional deformable member (21) is brought closer and closer to the deformable barrier (20) until the point where the two deformable members (20, 21) contact each other and dissipate energy therebetween.

[0109] The base member (5) is the only portion of the arrestor (100,101,102,103) in contact with the ground (G). The base member (5) is substantially planar, to maximise contact with the ground (G) and provide a leading edge (9). The leading edge (9) is integrally formed with the base member (5) and is inclined towards the ground (G). This is to prevent or at leastreduce the risk of the vehicle not mounting the base member (5) on initial contact. In some embodiments, the leading edge can be formed from a separate component and mounted to the base member (5) for use. This allows the leading edge (9) to be easily removed, or repaired if it sustains damage during an impact.

[0110] Figure 5C illustrates an alternative embodiment of the arrestor (103'), similar in working to arrestor (103), the arrestor (103') employs a lifting mechanism (61') and an alternative spare wheel (68) mounting location to arrestor (103).

[0111] The arrestor (103') comprises the same components as arrestor (103) however, the crash boxes (35) have increased dimensions. The oversized crash boxes (35) allow more space for the curved tubes (30) to move around whilst still being constraint therein. This arrangement can also soften the crash characteristics of the arrestor (103') providing a softer crash pulse or deceleration pulse for any occupants in the vehicle (1). Figures 5C-5E also illustrate a pin or bolt (35a) added to each of the front and rear crash boxes (35). The pins (35a) are configured to lock each tube (30a, 30b) to their respective crash box (35) and provide additional control to the rotation of each tube under impact.

[0112] Each of the pins (35a) can be more easily seen in Figure 5D, which is an enlarged view of the engagement member (10) and deformable members (20, 21) mounted thereto. Figure 5E is the same view as that of Figure 5D, with the deformable members (20, 21) removed. The pins (35a) are embodied as eyebolts in Figure 5D, each eye-bolt extending through one of the upper crash boxes (35) and through the end of each respective tube (30a, 30b). The eyebolt can thus be used as a shackle point for lifting / strapping the deformable rails (27) during loading and replacement.

[0113] The threaded stem (35b) of each eyebolt is about 200mm and runs right through the crash box (35) and tube therein (illustrated in Figure 11C). A head (17) of the eye-bolt can be threadingly disengaged from the stem (35b), to remove the protruding head (17) of each eyebolt from the deployed arrestor (103, 103') as illustrated in Figure 9A. The stem (35b) of pin (35a) thus allows an end of each tube (30a, 30b) to rotate around the pin (35a) within the crash box (35). A similar pin (35a) arrangement is configured for each of the lower crash boxes (35), without the head (17) to the eye-bolt as there is no lifting required from the lower tubes (30b).

[0114] In Figure 5E a series of baffles (8) can be seen located between the engagement member (10) and the base member (5) to support this joint under high-impact loading. The baffles (8) can be welded, or bolted, to retain them in position. Also seen in Figures 5D and 5E are a pair of supplementary legs (29a) which serve to partially support and to damp the rear bumper assembly (26) when the arrestor (103, 103') is being transported to a site for deployment.

[0115] Figure 5F illustrates an alternative damping assembly for the rear bumper (26) comprising a pair of flexible tensioners (12). Each tensioner (12) is mounted to between the engagement member (10) and the base member (5) to extend between a pair of fixed tensioner mounts (13). The tensioner (12) is also threaded through a guide (14) mounted to the crash box (35), the guide (14) illustrated in this embodiment as an eyebolt, allowing the tensioner (12) to turn through a 90-degree angle. The tensioner (12) can comprise a rope, a wire rope, a chain, a cable or similar flexible material that can be tensioned between the engagement member (10) and base member (5). The tensioner (12) is tightened (tensioned) to stop the "flapping" and reverberation of the base member (5) during towing, which is urged to bounce with the weight of the rear bumper system (26) supported thereon. The tensioners (12) can be easily removed or loosened when the arrestor (103, 103') is deployed, to reduce the risk of creating debris during an impact (which can negatively impact MASH requirements).

[0116] An upper, first surface (6) of the base member (5) supports all remaining components of the arrestor (100,101,102,103) and can be stiffened by box members or longitudinal rails(40) illustrated in Figures 5A and 5B. These rails (40) can extend along the base member (5) in short sections or can extend along the base member (5) from the engagement member (10) to a rear, trailing edge (11) of the base member (5). Additional smaller reinforcing members(41) can also be used for more localised stiffening of the base member (5) (see Figures 6A and 6B). These smaller reinforcing members (41) can be mounted to any one of more of the first side (6) and the second side (7) of the base member (5).

[0117] Figure 6A illustrates an underside perspective view of the arrestor (103) having a series of reinforcing members (41) disposed in spaced parallel relationship across the base member (5) and located toward the leading edge (9). In addition, a series of friction members or feet(45) are arranged in pairs in a "chevron" configuration across the entirety of the second side (7) of the base member (5).

[0118] These feet (45) can be seen in greater detail in Figure 6B, protruding from the second, underside (7) of the base member (5), assisting in supporting the arrestor (100,101, 102, 103) on the ground surface (G) and increasing frictional engagement therewith.

[0119] The base member (5) can be made from a single panel, but alternatively can be formed from two or more panel sections (5a, 5b) and sub-assembled with the engagement member (10) or other subsystems of the arrestor (103'), as illustrated in Figure 6C. The sections (5a, 5b) can be welded together, or bolted together and can use connectors (5c) in the form of metal plates, bolted, or riveted to the panels (5a, 5b) to support the joint therebetween. The rear most panel (5a) is also illustrated in Figure 6C to have a side skirt (9a) similar to the lip (9) to improve the engagement with the ground surface (G) and to stop objects and crash debris from being propelled under the base member sections (5a, 5b) during an impact.

[0120] Manufacturing the base member (5) from two panels (5a, 5b) allows the panels to be made from different materials and / or different material grades and / or different material thicknesses (or gauges). In Figure 6C, it is contemplated that the forward most portion (5b) will be formed from steel in an 8mm gauge material. This places more weight over the axles (wheels 70) of the arrestor (103') and provides mass to the arrestor (103') in use. Meanwhile, the rear most portion (5a) can be formed from aluminium in an 8mm thickness (for example aluminium 5083-H116), which reduces the weight of the arrestor (103') and reduces the unsupported weight, cantilevered off the wheels (70), when the arrestor (103') is in the stowed configuration for transportation. In this manner, the material and gauge of the base member (5) or base member portions (5a, 5b) can also be tailored to adjust the overall mass of the arrestor (103, 103'). The rear most section (5a) in Figure 6C is illustrated to have a series of evenly spaced swages or forms (41a) extending perpendicularly to the engagement member (10). These forms (41a) provide stiffness to the base member (5) without incurring any mass penalty, as experienced with the use of reinforcing members (41) in arrestor (103). The feet(46) are arranged across the base member (5) to avoid intersecting with the forms (41a).

[0121] Figures 7A and 7B illustrate an enlarged perspective view of a single foot (46) disengaged (7 A) and aligned for engagement (7B) with the base member (5). The foot (46)comprises an elongate body (47) supporting at least one (here two) fastener (49) for selectively engaging and disengaging the foot (46) from the base member (5). The body (47) can be formed integrally with the fastener, for example a protruding spigot or a captive nut, or can be manufactured separately. The body (47) supports a high friction surface (48) that extends from the body (47) toward the ground (G) when mounted to the base member (5). These feet (45) increase the friction between the base member (5) and the ground (G) to minimise or at least reduce movement of the arrestor (100,101,102,103) during an impact and to increase the friction with the ground (G) to dissipate heat via said frictional engagement. After each use, the feet (45) can be removed, replaced or re-treaded ready for subsequent use. The high friction surface (48) can be made from rubber, recycled tyres, or resins and plastics that are available.

[0122] Returning to the tube mounting and crash boxes (35), Figure 8 illustrated and enlarged perspective view of a front end of the arrestor (103). For ease of view, selected components of the bumper system (26) have been removed to reveal the bumper beam (28). The beam (28) is formed from four beam portions (28a-28d) arranged in closed formation to define a perimeter of the bumper system (26). These beam portions can be formed from rolled or extruded sections and are preferably formed from metal, e.g. steel, aluminium etc. They are configured to sit above the ground surface (G) within an acceptable local bumper height range, when the arrestor (103) is deployed. Also illustrated in Figure 8 are the legs (29) supporting an underside of beam portion (28b) and taking the weight of the bumper system (26) thereon. These legs (29) can be solid tubes but can alternatively contain damping units (hydraulic or springs) to thereby reduce noise and vibration when the arrestor (103) is being transported to a work site.

[0123] With most of the bumper system (26) removed in Figure 8, the crash boxes (35) mounting the tubes (30) are readily visible. Illustrated in Figure 9A, the crash boxes (35) comprise a mounting plate (36), a pair of opposing side plates (37), and a pair of opposing end plates (32). The mounting plate (36) has four spaced apertures for affixing the mounting plate (36) to either of the bumper system (26) or the engagement member (10), wherein the side plates (37) and end plates (32) can then be arranged to form a perimeter around the endportion (31) of the tube (30b). These plates (37, 32) can be cut from the arrestor (103) after a crash event to enable the tubes (30) to be replaced.

[0124] Figure 9B illustrates the end portion (31) of a tube (30b) which is welded or otherwise affixed to a mounting flange (34). The flange (34) is formed from a plate with a central aperture for receiving the end portion (31) of the tube (30b). The end portion (31) of each tube (30b) extends through the aperture of the flange (34) to allow for the flange (34) to be welded around the periphery of the tube (30). The weld (31a) can be continuous or can be disposed in short runs around the end portion (31) of the tube (30b). The flange (34) is substantially square and planar and provides at least one protruding tab (33) for mounting engagement with the plates (37, 32) of the crash box (35). This reduces the difficulty of achieving a sound engagement between the tube (30) and the crash box (35) facilitating ease of mounting and replacement of the tubes (30) of the series of deformable rails (27).

[0125] When the end portion (31) of the tube is inserted into the crash box (35) the one or more tabs (33) are welded to adjacent side and end plates (32, 37) to anchor the flange (34) and thereby anchor the tubes (30a.30b) within the respective crash box (35). Each of the side plates and end plates (32, 37) provides weld access apertures (32a, 27a) for welding between the crash box (35) and the flange (34). The end portion (31) of the tube (30b) extends through the mounting flange (37) defining an initiator (31 b) at the front of each tube (30). The initiator (31 b) extends forward of the weld apertures (32, 37a) to the mounting plate (36) when mounted in the crash box (35). The pins / bolts (35a) can be received in the initiators (31 b) to better control the motion and release of the tubes (30a, 30b) from within the respective crash box (35), as shown in Figure 11C.

[0126] To help address impact overlap issues (the alignment between the engagement structure and the errant vehicle when viewed in a top view), the inventor looked for an engineered connection between the tubes (30), the deformable rails (27) and the trailer chassis (50). The crash boxes (35) proved to be surprisingly effective during crash testing whereby the tube end (31) is encapsulated within the crush box (35), and a fracture point is engineered into the connection to allow the tube ends (31) to rotate, twist, etc. and deform within the crash box (35) i.e. in a controlled manner. The fracture points are shown in Figure 9B as a plurality of tabs (33) protruding from the mounting flange (34).

[0127] The tabs (33) are welded to the crash box (35) through weld apertures (32a, 37a) making the mounting flange (34) a sacrificial component. The tube (30) has a wall thickness of about 6mm-14mm, the plates of the crash boxes (35) have a wall thickness of about 8mm- 16mm and the mounting flange (34) has a wall thickness of about 4-10mm. As such, the plates (32, 36, 37) of the crash box are thicker than walls of the tubes (30), each of which are thicker than a thickness of the mounting flange (34).

[0128] When mounted to the arrestor, the tubes (30) are held in place by the crash box (35) encapsulating the mounting flange (34) welded around the tube (30). Upon impact, the 6mm mounting flange (34) (as the weakest part within the crash box (35)) fails, allowing the tube (30) to rotate and deform within the crash box as dictated to it by the forces of the particular impact. Allowing for the tube ends (31) to rotate and twist within the crash boxes in a controlled manner. Any fragments of the tabs (33) or mounting flange (34) are captured and retained within the crash box (35) to assist with debris control. During an impact event, the forward section or initiator (31 b) of each tube (30) is impacted by the end plate 36 triggering the initiator (31 b) to begin collapsing (plasticly deforming) in a regular and efficient energy absorbing, axial manner. This plastic deformation of the tubes (30) can assist in dissipating kinetic energy from the impact.

[0129] Figure 10 illustrates a perspective view of the series of deformable rails (27) with one of the upper tubes (30a) offset from the assembly to reveal the upper restraining leash (38a). This leash (38a) extends through the entire length of the upper tubes (30a) and is mounted at opposing ends thereof to the engagement member (5). The mountings are illustrated in more detail in Figures 11A and 11 B.

[0130] A mounting plate (23) is affixed to the end plate (36) of the crash box (35) with an eyelet (23a) or similar mounting feature, whereby an end portion (39) of the leash (38a) can be selectively engaged and disengaged with the eyelet (23a) to secure the leash (38a) within the tube (30a). Figures 11A-11C also illustrate the pin (35a) with as an eye-bolt head (17) which can be used for constructing the arrestor (100, 101, 102, 103, 104) and can also be used for lifting and positioning the arrestor for deployment. Figure 10 additionally illustrates a rear bumper deformable member or third deformable member (22) mounted to an opposing side of the bumper system (26) to the second deformable member (21). Like the first deformablemember (20) and the second deformable member (21), the third deformable member (22) can be a replaceable barrier, a honeycomb barrier, or a tailored barrier. Each of the deformable members (20, 21, 22) can be replaced after an impact, and selectively reengaged to provide a tailored level of energy absorption to the arrestor (100,101, 102, 103).

[0131] Figures 12A and 12B illustrate respectively, a side view and a top view of the arrestor (103). The tubes (30) extend from the engagement member (10) towards the leading edge (9) but stop short of the leading edge (9). The upper and lower tubes (30a, 30b) are not positioned parallel to the base member (5) but instead flare outwardly, diverging from the leading edge (9) towards the engagement member (10). This orientation assists in improving the management of crash energy during the impact. This orientation can provide a more efficient crush pattern to the tubes, minimising the likelihood of a vehicle diving under the barrier while also reducing the likelihood of the upper tube (30a) and the lower tubes (30b) being splayed away from each other and not properly engaged. Poor engagement with the tubes (30) can result in the tubes (30) bending or otherwise deflecting away from the impacting vehicle: this is an inefficient means of dissipating kinetic energy as once bent out of the way, the tube can absorb little further energy. A consistent, axial collapse of the tube (30) provides the most efficient energy absorption, but this form of axial collapse is unlikely to be sustainable over the length of the tube (30) due to the impacting angle of the errant vehicle and other real- world factors.

[0132] The top view of Figure 12B illustrates a pair of longitudinal rails (40) that extend from the trailing edge (11) of the base member to the engagement member (10) and protrude towards the leading edge (9) only as far as the deformable barrier (20). These longitudinal rails (40) provide a stiffening effect to the base member (5) and facilitate the mounting of the arrestor to a trailer or prime mover for ease of transportation.

[0133] Figures 13-16 illustrate stiffening structures within the arrestor (102, 103) to facilitate transport and performance of the arrestor when deployed. Figure 13 illustrates a chassis (50) configured from a plurality of frame members. A lower portion of the chassis (50) (in highlight) comprises a plurality of frame members extending both laterally (51) and longitudinally (52) across a breadth and a length of the base member (5). Although illustrated in Figures 13-16 as a plurality of beams and bars the components of the chassis (50) form a support structurein the form of a roll-cage structure and can be formed from beams, bars, rolled sections, tubes and the like.

[0134] Figure 14 illustrates a fire wall structure (53) oriented vertically and located between the support member (15) and the engagement member (10). The fire wall (53) comprises vertical support members (54) and horizontal support members (55).

[0135] Figure 15 illustrates and internal 3D framework (56) of the support member (15). The framework (56) comprises a plurality of beams (59), perimeter beams (57) braces (58) to form the 3D framework. These beams (57, 58, 59) can be bolted or welded together and can be formed from rolled sections, extrusions, or solid bars. In preferred embodiments, the 3D framework is primarily constructed from steel or similar strength metals to reduce the risk of damage or deformation during an impact. The 3D framework of the support member (15) is anticipated to last for the life of the arrestor (103) and is not a deformable or replaceable component of the arrestor (103). Where additional weight is required the 3D framework can provide cavities for insertable weights to further increase the mass of the arrestor (103).

[0136] The 3D framework (56) is further configured to support portions of a lifting mechanism enabling the arrestor (103) to transition between a stowed and a deployed configuration. Once contemplated lifting mechanism (61) is illustrated in Figure 17A, having an articulated linkage (63) and an actuator (62). The actuator (62) is configured to selectively drive the linkage (63) thereby raising and lowering the arrestor (103) relative to the ground (G) on demand.

[0137] Figure 17B illustrates an alternative embodiment of the lift mechanism (61'), as mounted to arrestor (103'). The lift mechanism (61') comprises an upper cross member or torsion bar (75) pivotally mounted to each of a pair of trailing arms (76) by air struts (62'). The torsion bar (75) is engaged via a pair of torsion bar mount brackets (77) to a pair of damper units (78). Each of the pair of damper units (78) is respectively mounted via a seat (79) to each respective trailing arm (76). Fluid can be transmitted to and from the damper units on demand, to raise or lower the lift mechanism (61') and thereby transition the arrestor (103') between the stowed configuration for transport, and the deployed, operative configuration at the worksite.

[0138] A rearmost portion of each trailing arm (76) is rotatably mounted to a lower suspension cross-member (80) having a stabilizer or sway bar (81) disposed thereacross, the sway bar (81) mounted to the trailing arms (76) via at least one sway bar bushing (82). At a foremost position on each trailing arm (76) is an upper control arm (84) which in turn supports a knuckle (83) for rotatably supporting one of the pair of wheels (70). The subframe (60) is thus used to mount the main suspension components of the arrestor (103') and also to configure the lift mechanism (61').

[0139] Figure 16 illustrates the subframe (60) of the arrestor (103) in the form of a lower perimeter frame for supporting a suspension and lifting mechanism (61, 61') for the arrestor (103, 103') to enable the arrestor (103, 103') to be raised and lowered between the stowed configuration for transport, and the deployed, operative configuration at the worksite.

[0140] Figure 18 illustrated one embodiment of the arrestor (103) having a trailer mounting frame (64) and towing hitch (65) for attaching the arrestor (103) to a prime mover, illustrated as a utility vehicle or ute (2).

[0141] Returning now to Figures 5A and 5B, a variety of optional features can be mounted to the arrestor (100, 101, 102, 103) for ease of use and for compliance with regulatory requirements. For example, the arrestor (100,101,102,103) can additionally provide an arrow board (66) for providing directional signage around an advance warning area or an adjacent clearance area. This signage can be a mere warning or a direction to road user to divert traffic flow away from the worksite. The arrow board (66) can be configured to transition between an operation and non-operational mode for ease of transport by virtue of hydraulics or pneumatic arms (66a) or similar mechanism.

[0142] The arrestor (103) can further provide alert beacons (67), or illumination to assist with visibility and safety around a work side. Said beacons (67) can further comprise auditory accompaniments.

[0143] The arrestor (100,101,102,103) is contemplated to be trailer mountable and provides the frame (64) and hitch (65) for ease of connection with a prime mover. The frame (64) can further be used to store additional equipment, such as remote barriers / signage, spare wheels (68), cones, tools and equipment (69) etc.

[0144] In the deployed configuration, wheels (70) on the trailer are raised by the lifting mechanism (61) to place the base member (5) in direct contact with the ground surface (G). In this deployed configuration, the wheels (70) are nestled within the support member (15) and shielded by mud guards (71) so as not to protrude from the support member (15) or interfere with the working of the arrestor (100,101,102,103). Further adornments to the arrestor (100,101,102,103) include taillights (72), registration plate (73) and warning signage locations (74) to name but a few.

[0145] In embodiments of the arrestors (100, 101, 102) where a trailer mounting is not incorporated into the support member (15), the arrestor can be mounted on a truck, or flat bed, and simply lifted into position on the ground surface (G). This negates the need for trailer mounting, many of the reinforcement frameworks, wheel, lifting mechanism and subframe components of the arrestor. Some of the reinforcement frameworks are still required as a form or roll cage to provide strength, support and torsional stiffness to the arrestor in use.

[0146] The invention also provides a method for deploying a vehicle arrestor system, the method comprising the steps of: delivering the vehicle arrestor (100, 101, 102, 103) to a target location in a stowed configuration; positioning a base member (5) of the arrestor above a ground surface (G) of the target location, the leading edge (9) of the base member (5) oriented towards a source of oncoming vehicles; and deploying the vehicle arrestor by bringing the base member (5) of the vehicle arrestor into frictional engagement with the ground surface (G). The source of oncoming vehicles can be a road, driveway, laneway, highway, motorway, freeway or the like.

[0147] In some embodiments, the vehicle arrestor (102,103,103') can be configured to selfdeploy, using the lifting mechanism (61,61') to raise and lower the base member (5) between the stowed and deployed configurations. In other embodiments, a crane, forklift or similar device is required to locate, orient and deploy the arrestor (100, 101).

[0148] Once in the deployed configuration, the utility vehicle or prime mover is disconnected from the arrestor, to avoid any damage thereto. A further reason for disconnecting the utility vehicle or prime mover is that if the arrestor (100, 101, 102, 103) was to be attached to the utility vehicle the arrestor would not be as effective, the additional mass and connection to the utility vehicle hampering the very means by which the arrestor operates. Adding the massof a connected vehicle would change the crash dynamics of the arrestor substantially. Both in the "Catch" (or static, attenuation) phase, by adding more mass to the arrestor, and also during the "Slow" (or arrest) phase as a physical impediment to the necessary movement of the arrestor through the arrest phase. Not being connected to a prime mover during deployment is commercially useful, as the prime mover can be redeployed to other tasks and does not need to remain with the arrestor (100, 101).

[0149] Typical truck mounted attenuators rely of the mass of the truck (or attachment vehicle) to provide sufficient mass to support the attenuator: there is no such thing as too much mass. In these products, the large mass of the truck is being used entirely to support the deformable structure, and all energy dissipation is confined to the deformation of the errant vehicle and the deformable structure. The truck supporting the attenuator is not intended to be damaged in an impact, as this would render the TMA unusable after every impact. The present arrestor is to be distinguished over these truck mounted attenuators, as the present arrestor is design to receive and combine with the errant vehicle, such that the combined mass of the vehicle and the arrestor continue to move together but at a greatly reduced velocity to that of the initial vehicle velocity. The friction between the base member of the arrestor and the ground surface then dissipates remaining impact energy by means of heat, generated from friction between the ground surface and the base member. In this manner, the ability of the arrestor to move, once combined with the vehicle, is a necessary function of the arrestor for impacts over a certain speed.

[0150] It will be appreciated by persons skilled in the art that numerous variations and modifications may be made to the above-described embodiments, without departing from the scope of the following claims. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

[0151] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein.

[0152] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

[0153] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, ie. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.LEGEND

Claims

THE CLAIMS1. A vehicle arrestor for catching and stopping a moving vehicle, comprising: a base member having an upwardly facing first surface for receiving the moving vehicle thereon and an opposing second surface for arranging in frictional engagement with a ground surface, the base member unconstrained to the ground surface; and an engagement member for engaging with the moving vehicle, the engagement member disposed on the first surface of the base member, wherein the base member and the engagement member are configured to engage with the moving vehicle, combining a mass of the moving vehicle with a mass of the arrestor to transfer momentum from the moving vehicle to the arrestor, and thereby decelerate the moving vehicle.

2. The arrestor of claim 1, wherein the arrestor is free to move in combination with the moving vehicle after engaging therewith.

3. The arrestor of claim 1 or claim 2, wherein energy is transferred from the moving vehicle to the arrestor, imparting a velocity thereto on engagement with the moving vehicle.

4. The arrestor of any one of claims 1-3, wherein the frictional engagement between the ground surface and the second surface of the base member dissipates energy from the combined moving vehicle and arrestor by means of friction.

5. The arrestor of any one of claims 1-4, wherein the arrestor further comprises a support member in contact with the engagement member, the support member configured to stabilise the engagement member under load.

6. The arrestor of any one of claims 1-5, wherein the engagement member comprises at least one attenuator.

7. The arrestor of claim 6, wherein the at least one attenuator is a deformable barrier, the deformable barrier configured to deform on contact with the moving vehicle to engage with the moving vehicle and dissipate kinetic energy through the deformation of the deformable barrier.

8. The arrestor of claim 7, wherein the deformable barrier is part of a replaceable cassette.

9. The arrestor of claim 7 or claim 8, wherein the deformable barrier comprises a support, at least partially surrounding a perimeter of the deformable barrier.

10. The arrestor of any one of claims 6-9, further comprising a bumper system located towards a leading edge of the base member.

11. The arrestor of claim 10, wherein at least one of: (i) a second attenuator is mounted to a front portion of the bumper system opposing the engagement member; and (ii) a third attenuator is mounted to a rear portion of the bumper system.

12. The arrestor of claim 10 or claim 11, wherein the bumper system is supported by at least one leg extending between the bumper system and the base member.

13. The arrestor of any one of claims 10-12, wherein the bumper system is configured to support at least one of a lighting array, a registration plate, signage and an alert beacon.

14. The arrestor of any one of claims 10-13, wherein the engagement member further comprises a deformable member, extending between the bumper system and the engagement member, configured to deform under load.

15. The arrestor of claims 14, wherein the deformable member is mounted to at least one of the engagement member and the bumper system by a sacrificial crash box.

16. The arrestor of any one of claims 1-15, wherein the leading edge of the engagement member is turned downwardly towards the ground surface.

17. The arrestor of any one of claims 1-16, wherein the base member comprises a plurality of friction increasing members disposed on the second surface.

18. The arrestor of claim 17, wherein the friction increasing members are selectively engageable with the base member.

19. The arrestor of any one of claims 1-18, wherein the support member comprises an internal framework to channel kinetic energy away from the engagement member during an impact.

20. The arrestor of claim 19, wherein the chassis supports ground engaging members configured to move between a deployed configuration and a stowed configuration.

21. An arrestor for decelerating a moving vehicle, comprising: a base member having a friction surface and an opposing support surface, the support surface supporting an engagement member thereon, configured to engage a moving vehicle wherein the friction surface is disposed in direct contact with a ground surface, such that friction between the first surface and the ground surface resists movement of the base member when impacted by the moving vehicle, the base member unconstrained to the ground surface.

22. The arrestor of claim 21, wherein the engagement member is configured to engage with the moving vehicle on contact therewith, such that a mass of the moving vehicle is combined with a mass of the arrestor propelling the combined vehicle and arrestor forward together and dissipating kinetic energy via friction generated between the first surface and the ground surface.

23. The arrestor of any one of claims 1 -22, wherein the arrestor is either engageable with a prime mover to transport the arrestor to a worksite; or mounted to a chassis, for transporting the arrestor to a work sire.

24. A method for deploying a vehicle arrestor system, the method comprising the steps of: i. delivering the vehicle arrestor to a target location; ii. positioning a base member of the arrestor above a ground surface of the target location such that a leading edge of the base member is oriented towards a source of moving vehicles, the base member supporting a vehicle engaging member thereon for engaging a moving vehicle; and iii. deploying the vehicle arrestor by bringing the base member into frictional engagement with the ground surface, the base member unconstrained to the ground surface.

25. The method of claim 24, wherein the vehicle engaging member comprises at least one of an energy absorbing member and a deformable member.

26. The method of claims 24 or claim 25, wherein the step (i) of delivering the vehicle arrestor uses a disengageable prime mover to transport the vehicle arrestor mounted to a chassis.

27. The method of any one of claims 24-26, wherein the step (i) delivering the vehicle arrestor uses a truck and / or forklift to transport the vehicle arrestor.

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