AU2017268574B2

AU2017268574B2 - Energy Absorption Device

Info

Publication number: AU2017268574B2
Application number: AU2017268574A
Authority: AU
Inventors: Dallas Rex James
Original assignee: Valmont Highway Technology Ltd Australia; Valmont Highway Technology Ltd
Current assignee: Valmont Highway Technology Ltd
Priority date: 2009-04-07
Filing date: 2017-11-29
Publication date: 2019-02-14
Anticipated expiration: 2030-04-07
Also published as: AU2017268574A1; AU2019202998B2; AU2019202998A1; AU2014277803A1

Abstract

Abstract A method of absorbing energy from a moving object upon impact wherein the method comprises the steps of: utilizing at least two types of energy absorbing elements, to absorb at least some of the energy of the impact, in an energy absorbing apparatus, wherein a first type of element absorbs the majority of the energy absorbed by a first compression step of a compressing fluid contained within a first sealed volume, and dissipated said majority of the energy absorbed by the apparatus, the first type of energy absorbing element is in the form of a shell comprising at least one external wall; wherein at least one subsequent type of energy absorbing element continues to absorb energy after the first type of element has ceased operation and can no longer absorb energy via a second compression step of compressing said subsequent energy absorbing element(s).

Description

ENERGY ABSORPTION DEVICE

This application is a divisional application of AU2014277803 the entire contents of which are incorporated herein by reference

STATEMENT OF CORRESPONDING APPLICATIONS

This application is based on the Provisional Specification filed in relation to

New Zealand Patent Application Number 576140, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This invention relates to an energy absorbing device.

BACKGROUND ART

A wide variety of energy absorbing apparatus are available for use in situations where it is desirable to absorb the energy of an impact.

For ease of reference only, the present invention will now be described with regard to roading applications, where impact of an erratic vehicle with a stationary object, (such as for example only: a wall, utility, pole or tree) can cause severe injury and/or death to occupants travelling in the vehicle. Similarly, vehicles that have been driven off course may be significantly slowed down by contact with an energy absorbing apparatus, reducing the danger when entering areas of risk, particularly at high speeds.

Vehicle collisions with stationary objects are a large contributor to deaths and serious injuries. To reduce the damage to occupants during a collision, a number of assemblies have been devised to absorb and/or transfer the energy from the impact.

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It is well known to use containers filled with water or sand as energy absorbing devices between roadways and stationary objects. One of the major disadvantages of this system is that the devices are relatively heavy, and in the case of the water filled devices, often difficult to maintain.

It is also well known to use air tight containers to absorb impact energy. These are somewhat effective, however once the container has had an initial impact and the container shattered or broken, there is no further way that energy can continue to be absorbed. These containers are known to be used both on land and sea, however they are not particularly effective when receiving a high energy impact.

US Patent 5,123,775 describes an impact attenuator to absorb the impact of vehicular collisions. The device described in this patent includes a fibreglass shell which defines a cavity in the interior thereof. Housed within the cavity is a plurality of layers of empty aluminium beverage cans. Each layer consists of a plurality of cans stacked end to end in a number of columns in the direction of anticipated impact. Each of the layers is then separated by a cardboard divider to maintain separation between the layers, and the assembled cans are then surrounded by a burlap shroud before being encased within the fibreglass shell.

This assembly has a number of disadvantages. As the aluminium cans are stacked end to end within the layers, the device will only function at its most effective when the collision occurs in a direction which is head-on into the end of the cans. This limits the types of situation where this assembly can be used and also may increase risk to a vehicle occupant if the apparatus is impacted from the nonpreferable angle. Additionally as the individual layers of cardboard and cans are not fixed together, the energy absorbed on impact is not readily transferred throughout all layers of the device, limiting the effectiveness of the entire device to absorb impact. This system is also fairly labour intensive to produce, as individual cans need to be correctly positioned within columns and then layers, with

2017268574 21 Dec 2018 cardboard dividers. The can and cardboard interior needs to then be encased in a burlap sack, then inserted within a fibreglass shell, making the process of producing the assembly time consuming and labour intensive.

A number of other reading barriers are known, such as those constructed using tyres. One such longitudinal barrier is described in WO 03/097964. This patent specification describes a longitudinal barrier constructed from a plurality of tyres that are configured in a staggered brick type fashion or are stacked on top of each other to form columns. The tyres are held in position by a series of cables, wire rope, or stakes depending on the configuration of the tyres. One disadvantage with this system is that tyres solely absorb the impact of a vehicle. For example the energy of the impact is only transferred to horizontally adjacent tyres via upright supports (binding devices 16, 26 or 47) The binding devices have a small surface area so the transfer of force to a tyre is limited. This invention is also labour intensive as it requires holes 13 to be cut into the tyres, refer to Figures 1,3 and 5. Once the tyres have had holes introduced to them, there is a reduction in the amount of energy that can be absorbed or transferred through the system, further reducing the effectiveness of the tyres in absorbing impact. The barrier of WO 03/097964 is also limited slightly in that it is not surrounded by an outer shell or casing. The addition of an outer casing or shell seals the air inside the barrier, providing further resistance when the barrier is absorbing an impact.

In summary, the problem with the prior art assemblies such as shown in US 5,123,775 and WO 03/097964 is the fact the vehicle itself still has to absorb the majority of the force of impact, which cannot be transferred or absorbed by the assembly, for the reasons mentioned above. In the case of US 5,123,755 the impact absorption efficiency is limited is by the aluminium cans not being connected to either each other or the layered cardboard. On impact, the cans may fall apart from each other once the fibreglass housing has been shattered, further

2017268574 21 Dec 2018 increasing the energy that needs to be absorbed by the vehicle instead of the barrier. These problems occur due to both prior art assemblies relying on the resilience of the individual materials to absorb the majority of the impact. Each of the above assemblies are also potentially time consuming and labour intensive to manufacture on a large scale.

It would therefore be useful to have an assembly where the elements within the assembly are all interconnected in such a way, to increase the amount of energy that is absorbed and/or transferred to the assembly from an impacting vehicle, thereby decreasing the amount of force conveyed back to the occupants of the colliding vehicle. Additionally, it would also be an advantage to have an assembly that could be quickly and easily manufactured using readily available materials. It would be a further advantage to have an assembly that could be constructed in a range of shapes, such as; circular, square; a line, to suit a range of applications, without being expensive to construct.

Conventional energy absorbing apparatus and road barriers including those as described above only utilise a single type of energy absorbing element. It would also be useful if there could be provided an energy absorbing device which can utilise at least 2 types of energy absorbing elements.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not

2017268574 21 Dec 2018 constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or 'comprising' is used in relation to one or more steps in a method or process.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is provided a method of absorbing energy from a moving object upon impact wherein the method comprises the steps of:

utilizing at least two types of energy absorbing elements, to absorb at least some of the energy of the impact, in an energy absorbing apparatus, wherein a first type of element includes first sealed volume and absorbs the majority of the energy absorbed by the apparatus by a first compression step of a compressing fluid contained within the first sealed volume, the first type of energy absorbing element is in the form of a shell comprising at least one external wall and dissipates said majority of the energy absorbed by the apparatus;

wherein at least one subsequent type of energy absorbing element continues to absorb energy after the first type of element has ceased operation and can no longer absorb energy via a second compression step compressing said at least one subsequent type of energy absorbing element;

wherein the first type of element absorbs energy until the first sealed volume becomes no longer sealed,

2017268574 21 Dec 2018 wherein the shell defines the first sealed volume, and the first type of energy absorbing element absorbs energy, at least in part, by compression of the fluid within the shell, until the shell ruptures, and wherein the subsequent types of energy absorbing elements include a second type of energy absorbing element that absorbs energy, at least in part, by being crushed, and wherein the second type of energy absorbing element includes one or more interior walls within the energy absorbing apparatus, further defining the shell, and wherein the subsequent types of energy absorbing elements include a second sealed volume containing a fluid within the interior walls and absorb energy at least in part by compression of the fluid in the second sealed volume, followed by crushing of the interior walls.

According to another aspect of the present invention there is provided an energy absorbing apparatus for absorbing energy from a moving object upon impact, comprising:

at least two types of energy absorbing elements configured to absorb at least some of the energy of the impact, wherein a first type of energy absorbing element is formed by one or more external walls of the apparatus, defining an enclosed volume encompassing:

- a fluid; and

- a subsequent type of energy absorbing element, wherein the subsequent type of energy absorbing element is formed by a plurality of interior walls, the interior walls and the one or more external walls integrally formed and together defining a single unitary shell defining the enclosed volume, wherein each interior wall forms a tube spanning between opposing sides of the shell, and wherein the tubes are spaced part in the enclosed volume so that each is surrounded by the fluid;

wherein the first energy absorbing element absorbs and dissipates the majority of the energy absorbed by the apparatus by compression of the fluid contained within the enclosed volume until the shell ruptures, and wherein the subsequent type of energy absorbing element continues to absorb energy after the first energy absorbing element has ceased operation and can no longer absorb energy.

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BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1	shows a perspective view of the energy absorbing device of the present invention;
Figure 2	shows a perspective cross section of the energy absorbing device of Figure 1;
Figure 3	shows a perspective view of modular safety device in accordance with one preferred embodiment which includes a number of energy absorbing devices as shown in Figure 1;
Figure 4	shows a plan view of a modular safety device in accordance with another preferred embodiment which includes a number of energy absorbing devices shown in Figure 1; and
Figure 5	shows a plan view of a housing which includes a number of energy absorbing devices as shown in Figure 1 in accordance with a still further preferred embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Figures 1 and 2 show an energy absorption device 100 in accordance with one preferred embodiment of the present invention. The energy absorption device 100 is made from medium density polyethylene and has 6 external walls 101 - 106 which form an outer rectangular shell 200. As best seen in Figure 2 the shell 200 defines a first internal area 210 that acts as an air cushion when the device 100 is sealed on all sides as shown in Figure 1.

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The first internal area 210 is further defined by interior walls 300. As shown in Figures 1 and 2, interior walls 300 span across internal area 210 of the shell, running parallel between opposing sides of the shell 200. Interior walls 300 are octagonal in shape and define a space 310 within interior walls 300. In this embodiment there are four interior walls 300 shown, however it is envisioned that there may be any number of interior walls 300 located within shell 200.

In use, device 100 may be positioned to receive an impact from direction X, Y or Z or any angle in between as indicated by the axis in Figure 1. On impact, shell 200 contains air which is compressed by the initial energy of impact and this absorbs the majority of the impact energy then when the shell ruptures the remaining impact energy is transferred to (i.e. absorbed by) interior walls 300 which get crushed, absorbing more energy from the impact. As would be appreciated by a person skilled in the art, the more interior walls 300 positioned within housing 200 the more surfaces will be available for absorbing impact energy.

The devices 100 of the present invention may also be used as modules arranged within a further housing or arranged together to form a larger energy absorbing device.

Figure 3 shows a modular safety device generally indicated by arrow 500. The modular safety device 500 has four energy absorbing devices 501 - 504 which are connected by cables 505 and 506 which pass through apertures (not shown) in the energy absorbing devices 501 - 504. The modular safety device 500 in use can be wrapped around an object (not shown).

For example the modular safety device 500 can have multiple energy absorbing elements and can be wrapped around a power pole (not shown) one or more times to create one or more protective layers about the pole.

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Although not shown it should be appreciated that the energy absorbing elements

500 can also be orientated so as to absorb the energy of an impact along the longitudinal axis of the device 500.

Figure 4 shows a modular safety device 600 which has number of modular energy absorbing devices 601 which surround the trunk of a tree 602. The energy absorbing devices 601 have apertures in the form of an integrally moulded tube (not shown) which passes from side to side to enable connection of adjacent energy absorbing devices 601. The energy absorbing devices 601 are connected via a cable 603 which is threaded through adjacent energy absorbing devices which are then wrapped around a tree and the two cable ends are clamped together so as to form a ring.

Figure 5 shows an alternate modular safety device 700. The modular safety device

700 has a first housing 701 connected via bolts (not shown) to a second housing 702. The modular safety device 700 surrounds a power pole 703. The first housing

701 has had the top of the housing removed in order to show the energy absorbing devices 704 which are located therein. As can be seen the centrally located energy absorbing device of which only the top one of a stack of two can be seen is horizontally orientated (i.e. lying down). By way of contrast the side energy absorbing devices on either side of the centrally positioned stack of devices are orientated vertically (i.e. standing up).

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims.

Claims

WHAT WE CLAIM IS:

1. A method of absorbing energy from a moving object upon impact wherein the method comprises the steps of:

utilizing at least two types of energy absorbing elements, to absorb at least some of the energy of the impact, in an energy absorbing apparatus, wherein a first type of element includes first sealed volume and absorbs the majority of the energy absorbed by the apparatus by a first compression step of a compressing fluid contained within the first sealed volume, the first type of energy absorbing element is in the form of a shell comprising at least one external wall and dissipates said majority of the energy absorbed by the apparatus;

wherein at least one subsequent type of energy absorbing element continues to absorb energy after the first type of element has ceased operation and can no longer absorb energy via a second compression step compressing said at least one subsequent type of energy absorbing element;

wherein the first type of element absorbs energy until the first sealed volume becomes no longer sealed, wherein the shell defines the first sealed volume, and the first type of energy absorbing element absorbs energy, at least in part, by compression of the fluid within the shell, until the shell ruptures, and wherein the subsequent types of energy absorbing elements include a second type of energy absorbing element that absorbs energy, at least in part, by being crushed, and wherein the second type of energy absorbing element includes one or more interior walls within the energy absorbing apparatus, further defining the shell, and wherein the subsequent types of energy absorbing elements include a second sealed volume containing a fluid within the interior walls and absorb energy at least in part by compression of the fluid in the second sealed volume, followed by crushing of the interior walls.
2. The method of absorbing energy as claimed in claim 1, wherein the fluid is a gas.

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3. The method of absorbing energy as claimed in claim 2, wherein the fluid is air.
4. The method of absorbing energy as claimed in claim 1, wherein the interior walls are substantially tubular in shape and integrally formed with the shell, and wherein the interior walls extend across the shell along a major dimension of the shell.
5. The method of absorbing energy as claimed in claim 1, wherein prior to the first type of element ceasing operation, the first type of energy absorbing element absorbs between 50%-90% of the energy absorbed by the apparatus.
6. An energy absorbing apparatus for absorbing energy from a moving object upon impact, comprising:

at least two types of energy absorbing elements configured to absorb at least some of the energy of the impact, wherein a first type of energy absorbing element is formed by one or more external walls of the apparatus, defining an enclosed volume encompassing:

- a fluid; and

- a subsequent type of energy absorbing element, wherein the subsequent type of energy absorbing element is formed by a plurality of interior walls, the interior walls and the one or more external walls integrally formed and together defining a single unitary shell defining the enclosed volume, wherein each interior wall forms a tube spanning between opposing sides of the shell, and wherein the tubes are spaced part in the enclosed volume so that each is surrounded by the fluid;

wherein the first energy absorbing element absorbs and dissipates the majority of the energy absorbed by the apparatus by compression of the fluid contained within the enclosed volume until the shell ruptures, and wherein the subsequent type of energy absorbing element continues to absorb energy after the first energy absorbing element has ceased operation and can no longer absorb energy.

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7. The energy absorbing apparatus of claim 6, wherein each tube is deformable to absorb energy following rupture of the one or more external walls of the shell.
8. The energy absorbing apparatus of claim 6, wherein the fluid is a gas.
9. The energy absorbing apparatus of claim 8, wherein the fluid is air.
10. The energy absorbing apparatus of claim 6, wherein the first type of energy absorbing element absorbs energy by compression of the fluid within the shell until the one or more external walls of the shell ruptures.
11. The energy absorbing apparatus of claim 6, wherein the tubes absorb energy at least in part by being crushed.
12. The energy absorbing apparatus of claim 6, wherein the tubes extend across the enclosed volume along a major dimension of the shell.
13. The energy absorbing device of claim 6, wherein the tubes form a second enclosed volume containing a fluid, and wherein the second type of energy absorbing element absorbs energy at least in part by compression of the fluid in the second enclosed volume, followed by crushing of the interior walls.
14. A housing adapted for surrounding stationary objects, said housing including a number of energy absorbing devices as claimed in claim 6.