NL2024218A

NL2024218A - Impact attenuating system

Info

Publication number: NL2024218A
Application number: NL2024218A
Authority: NL
Inventors: Huting Tomas
Original assignee: Hato World B V
Priority date: 2019-11-12
Filing date: 2019-11-12
Publication date: 2021-07-20
Also published as: NL2024218B1; US20210138287A1

Abstract

An impact attenuating system (1; 2) is provided for attenuating impact onto a landing area when exercising freestyle sports such as freestyle cycling, freestyle motorbiking, skiing, snowboarding, skateboarding, inline skating, scootering and alike. The impact attenuating system (1) comprises a first inflatable structure (14). The first inflatable structure (14) comprises a first sheet (101) and a sheet (102). A first side (111) of the first sheet is in contact with and connected to a first side (112) of the second sheet along a first plurality of parallel first connection lines (103-1, 103-2, 103-2) to form a first plurality (104) of parallel first air chambers (104-1, 104-2, 104-3). The first plurality of parallel first air chambers is inflatable to form a first plurality of parallel first tubular airbags arranged side-by-side in a first plane substantially parallel to the top surface of the landing area. A top layer (110) may be provided. A second inflatable structure (24) may be provided on top of the first inflatable structure (14).

Description

IMPACT ATTENUATING SYSTEM

FIELD The invention relates to an impact attenuating system comprising an inflatable structure, in particular impact an attenuating system for attenuating impact onto a landing area when exercising freestyle sports such as freestyle cycling, freestyle motorbiking, freestyle skiing, (inline) skating, scootering, and alike.

BACKGROUND ART When exercising freestyle sports such as freestyle cycling, freestyle motorbiking, freestyle motocross (FMX), Bicycle Motocross (BMX), freestyle skiing, snowboarding, skateboarding, inline skating, snow sleds, scootering and alike, good impact absorption is important for safety of the athlete, especially when developing, practicing and exercising new moves and tricks, e.g., jumps, and/or when the risk for falling from some elevation is considerable. Impact attenuating systems, such as airbags, are often used for this purpose. For example, the BIGAIRBAG® FREESTYLE systems that are currently on the market provide a very good impact absorption. The BIGAIRBAG® FREESTYLE systems have a lower safety zone for reducing the risk of ground contact while providing stability for a realistic landing and an upper zone providing optimum impact absorption by releasing air through the adjustable air valves. The bulb-like shape of the BigAirBag® FREESTYLE aims to provide a soft landing while also allowing for an easy exit and high throughputs. These systems provide a very good impact absorption. However, when exercising freestyle sports such as freestyle cycling and freestyle motorbiking, good impact absorption is just one of many wishes for an impact attenuating system. For example, the freestyle cyclist or freestyle motor biker also wants to drive across the impact attenuating system without being too much disturbed from the impact attenuating system, such as without experiencing too much bounce. Also, the bulb-like shape of the BigAirBag® FREESTYLE may not be optimal for some situations and some applications. For example, the bulb-like shape may deviate from the shape of the landing surface in an actual competition and/or may affect the flying time and thus the moment of impact when using it for exercising free style sports. There may e.g. be a wish for thinner systems, for lighter systems, for systems with a flatter upper surface and/or for systems which adapt more easily to the underground on which they are placed. Known impact attenuating systems thus suffer from various limitations and there is a wish to provide an impact attenuating system which alleviates at least one of the mentioned or any unmentioned limitations, or provides an alternative to existing systems.

SUMMARY A first aspect of the invention provides an impact attenuating system for attenuating impact onto a landing area. The impact attenuating system comprises a first inflatable structure. The first inflatable structure comprises a first sheet, and a second sheet. A first side of the first sheet is in contact with and connected to a first side of the second sheet along a first plurality of parallel first connection lines to form a first plurality of parallel first air chambers extending along a first direction.

The first plurality of parallel first air chambers is inflatable to form a first plurality of parallel first tubular airbags arranged side-by-side in a first plane substantially parallel to surface of the landing area under the impact attenuating system. When inflated, this an array of horizontal, side-by-side tubular air-bags is achieved to provide an impact attenuating structure for attenuating shocks when a sportsman is exercising so-called freestyle sports, in particular when landing on the landing area.

The impact surface corresponds, during use, to the externally facing upper surface of the impact attenuating system.

The impact attenuating system, when inflated, may be considered to works as a harmonica: when an objects impacts on one or some adjacent first tubular airbags below the impact surface, these airbags reduce in dimension in a direction perpendicular to the impact surface and perpendicular to the first plane while each of these one or some adjacent first tubular airbags substantially maintains its volume, such that they expand in dimension in the first plane in a direction substantially perpendicular to the first direction, whereby cause the neighboring first tubular airbags to reduce in dimension in the first place in the direction substantially perpendicular to the first direction and/or to be somewhat replaced in the first plane away from the one or some adjacent first tubular airbags in the direction substantially perpendicular to the first direction. The first plurality of parallel first air chambers may thus be considered to act as an harmonica upon an impact and replies less than known systems an elasticity of the airbag material. Thus, the first and second sheets do not need to be of such a high elasticity as in some prior art systems With the impact attenuating system, there may be some air communication between adjacent air chambers when there is an impact, but the applicant believes that the working mechanism does not rely on this and that such air communication is not very relevant for the system to work. After being inflated, the pressure in and throughout the system is believed to be and remain quite uniform.

The first sheet may be impermeable to air, which may further be referred to as a first air-impermeable sheet.

The first sheet may be semi-impermeable to air, which may further be referred to as a first air-semi-impermeable sheet.

Likewise may the second sheet may be impermeable to air, which may further be referred to as a second air-impermeable sheet.

The second sheet may be semi-impermeable to air, which may further be referred to as a second air-semi-impermeable sheet.

The skilled person will understand which degree of semi-impermeability is suitable for use in an inflatable structure and requirements and limitations depending on, e.g., the use of a continuous supply of air using, e.g., a blower.

In the below, air-permeable and air-semi- impermeable sheets may together also be referred to as a predominantly air- impermeable sheets or as (at least) semi-impermeable sheets.

The first sheet and the second sheet may be made of any suitable materials, such as PCV-coated textiles, TPU, HDPE and other plastics.

The first sheet and the second sheet may for example be made of a commercially available tarpaulin trom Mehler Texnologies, which combines properties such as strength, durability, flexibility and elasticity.

Other top sheet materials may, for example, be HDPE.

The impact attenuating system may thus provide for an efficient damping while being thin and light.

The impact attenuating system may thus be easy to transport.

The impact attenuating system may have a much reduced degree of rebound compared to known systems.

The impact attenuating system may be easy and comfortable to drive across with a bike, motorbike or alike.

As impact attenuating system may, in view of its low thickness and/or its working principle, adapt well to the shape of the underground that it is placed on.

Prior art systems are usually specially adapted for the targeted use location and shaped to match the shape of the underground.

Prior art systems may easily show buckles, folds or flexures when placed on an underground with a different shape than the system as designed for.

Embodiments of the invention may adapt to the shape of the underground better.

For example, in embodiments, a sudden 10° degree change in slope of the underground may be accommodated for without the attenuating system being specifically adapted for that change in slope.

An another example, in embodiments, a 90° degree edge in the underground may be accommodated by arranging the impact attenuating system with the air chambers extending parallel to the edge, without the impact attenuating system being specifically adapted for the specific location with the 90° degree edge.

In an embodiment, the first side of the first sheet is connected to the first side of the second sheet along the first plurality of parallel first connection lines using a plurality of lines of adhesive, a plurality of lines of glue, a plurality of glue dots arranged along a line, a plurality of welds, a plurality of seams, a plurality of stitched seams, and/or a plurality of heat seals. The adhesive may, e.g., be a pressure sensitive adhesive. The glue may, e.g., be an epoxy resin. The seams may, e.g., be stitched seams obtained from stitching with a thread of any type suitable for airbags. The welds may, e.g., have been made using ultra-sonic welding or radio-frequent welding. The seals may, e.g., have been made using heat sealing. Heat sealing may use hot air and/or a hot surface for heating at least one of the first and the second sheet along a line, letting them contact each other while heated and cooling them while remaining in contact to create the heat seal line. Connecting the first side of the first sheet to the first side of the second sheet with continuous lines of adhesive, continuous lines of glue, continuous welding lines may create a substantially air-impermeable or air-semi- permeable connection line. Connecting the first side of the first sheet to the first side of the second sheet using discontinuous lines of adhesive, glue or welds or using stitched steams may create connection lines which are semi-impermeable to air, i.e., which may exhibit a small degree of leakage between two adjacent first tubular airbags. The small degree of leakage is well acceptable for the functioning of the impact attenuating system. Stitching may be, in particular, be an economically attractive way for connecting the sheets along connection lines.

In an embodiment, the first sheet is further in contact with and connected to the second sheet along a plurality of enclosures lines enclosing the first plurality of parallel first air chambers while to form at least one air supply chamber for distributing to and suppling air from a first air inlet to the first plurality of parallel first air chambers. The enclosure lines may be formed using lines of adhesive, lines of glue, lines of glue dots arranged along a line, welding lines, seams, stitched seams, and/or heat seal lines. The enclosure lines may be substantially impermeable to air or, e.g. when stitched seams are used, semi-impermeable to air. If the enclosure lines are semi- impermeable to air, the small degree of leakage may well acceptable for the functioning of the impact attenuating system; to compensate for any leakage, operating the system with a continuous flow of air, or operating the system while providing air at regular intervals, may provide the impact attenuating system with a substantially constant air pressure. The enclosure lines thus form a first enclosure, with a first air inlet, which not only encloses the first plurality of parallel first air chambers together in arrangement of connected air chambers, but also can distribute the air from the first air inlet via the at least one air supply chambers to the first plurality of parallel first air chambers.

In an embodiment, the connection lines are straight lines. In alternative embodiments, the connection lines are wobbled lines or zigzag lines extending along 5 the first direction. In embodiments, a subset of the plurality of connection lines are straight lines and another subset of the plurality of connection lines are lines of a different type. In embodiments, all connection lines in at least a subset of the connection lines comprise a straight section and a section of a different type, such as a straight section and a zigzag section.

In an embodiment, the plurality of enclosures lines comprising at least two enclosure lines arranged perpendicular to the connection lines and being spaced apart from the ends of the connection lines as far as these do not form enclosure lines. The spacing of the enclosure lines from the first plurality of parallel first air chambers creates air supply chambers extending along the enclosure lines to form at least one first air supply channel from the first air inlet to the first air chambers of the first plurality of parallel first air chambers. In embodiments, the at least two enclosure lines arranged perpendicular to the connection lines are spaced apart from the ends of the connection lines as far as these do not form enclosure lines by at least a distance in a range of 10 — 100 cm, such as in a range of 20 — 80 cm, such as in a range of 20 — 60 cm, such as in arange of 30 — 40 cm, measured when the first plurality of parallel first air chambers are in a deflated state. Such distances between the enclosure lines and the first plurality of parallel first air chambers may create an efficiently air distribution from the first air inlet via the at least one first air supply channels from the first air inlet to the first air chambers. Such enclosure lines may be efficient to manufacture. Such enclosure lines may allow an easy construction as the air distribution is integrated within the same system.

In an embodiment, the plurality of enclosure lines comprise or consist of a plurality of double-stitched seams. For example, the edges of the first and second sheets may be double-seamed, folded and stitched again after having been folded to create a strong and economically attractive connected.

In an embodiment, the impact attenuating system comprises an air blower connected to the first air inlet for providing the impact attenuating system with a continuous flow of air, or for providing the impact attenuating with air at regular intervals.

In an alternative embodiment, the impact attenuating system is arranged to cooperate with an external air blower. The impact attenuating system may comprise an air inlet connection for connecting an external air blower to the first air inlet for providing the impact attenuating system with a continuous flow of air, or for providing the impact attenuating with air at regular intervals.

In an embodiment, the first sheet and the second sheet are made of the same material.

The first sheet and the second sheet may, e.g., be made of materials commonly used for airbags, such as the materials used for BigAirBag® FREESTYLE.

The first sheet and the second sheet may, e.g., be made of technical coated fabrics comprising TPU, PVC, EVA, or PVC/PU blends and HDPE.

In embodiments, the first sheet has a first sheet length in a range of 1 — 100 meters and a first sheet width in a range of 1 — 100 meters, such as a first sheet length in a range of 5 — 100 meters and a first sheet width in a range of 2 — 40 meters such as a first sheet length in a range of 5 — 80 meters and a first sheet width in a range of 5 — 30 meters, such as a first sheet length in a range of 10 — 50 meters and a first sheet width in a range of 4 — 10 meters.

The impact attenuating system may thus be made in a wide range of dimensions, with a suitable dimension selected depending on its intended application.

A high length may be used in the major direction of use, e.g., the riding direction when landing from a ramp onto an impact attenuating system on a down-hill slope, to allow a safe landing at a wide range of distances and a safe continuation of the riding after the landing.

In an example, the first sheet has a length of 10 meters and a width of 6 meters, with, for example, connection lines at a spacing of 60 centimeters to form, when inflated, 45 cm-diameter tubular air bags, extending in the length direction of the first inflatable structure, i.e., in the longitudinal direction of a rectangular-shaped first inflatable structure.

In another example, the first sheet has a length of 10 meters and a width of 6 meters, with, for example, connection lines at a spacing of 60 centimeters to form, when inflated, 45 cm-diameter tubular air bags, extending in the width direction of the first inflatable structure, i.e., in a direction perpendicular to the length direction of the first inflatable structure.

In embodiments, the parallel first connection lines of the first plurality of parallel first connection lines extend in the length direction of the first inflatable structure when in a deflated state.

In alternative embodiments, the parallel first connection lines of the first plurality of parallel first connection lines extend in the width length direction of the first inflatable structure when in a deflated state.

In embodiments, the parallel first connection lines of the first plurality of parallel first connection lines are spaced apart at a distance in a range of 10 — 100 cm, suchas in arange of 20 — 80 cm, such as in a range of 20 — 60 cm, such as in a range of 30 — 40 cm, measured when the first plurality of parallel first air chambers are in a deflated state. The impact attenuating system may thus be made with, when inflated, a small thickness compared to some prior art systems which have a bulb-like shape. The impact attenuating system may thus be made in a wide range of thicknesses, depending on its intended application, a suitable thickness selected depending on its intended application. The smaller the distance, the smaller the height variation of the top surface of the first plurality of parallel first air chambers in inflated state will be. The height variation may be further reduced, and the surface characteristics influenced, by applying a top layer or top liner on the top surface; the smaller the distance, the flatter the top layer or top liner will be arranged and/or the less external force needs to be applied to the top layer or top liner to achieve a substantially flat top surface. The larger the distance, the higher the speed of manufacturing may be. In some embodiments, the substantially flat top surface is a flat top surface. In other embodiments, the substantially flat top surface has a height variation of less than 25%, for example less than 15%, for example less than 10%, for example less than 5% of the height of an first tubular airbag in the inflated state, where height variation is measured as the distance in the vertical plane between the vertical position of the top surface of the top layer on top of the first tubular air chamber and the vertical position of the top surface of the top layer in between two adjacent first tubular air chambers.

For example, the plurality of parallel first air chambers may be inflatable to form the first plurality of parallel first tubular airbags arranged side-by-side, in the length direction of the first inflatable structure when in the deflated state, in the first plane with a long axis of an ellipse-shaped cross-section or a diameter of a substantially circular cross-section in a range of 4 — 60 cm, such as in a range of 15 - 50 cm, such as in a range of 15 — 40 cm, such as in a range of 20 — 30 cm, measured when the first plurality of parallel first air chambers are in an inflated state.

In an embodiment, the first plurality of parallel first air chambers is inflated with air to form a first plurality of parallel first tubular airbags arranged side-by-side in a first plane substantially parallel to the impact surface. The impact attenuating system may thus be operational for use or for testing.

In an embodiment, the first plurality of parallel first air chambers is inflated using a continuous supply of air to form a first plurality of parallel first tubular airbags arranged side-by-side in a first plane substantially parallel to the impact surface. The impact attenuating system may thus be brought to operation and/or kept operational for use or for testing while any leakage of air from the impact attenuating system to the exterior may be compensated for. The impact attenuating system may thus be provided with a substantially constant internal pressure. The impact attenuating system may thus be provided with a substantially constant degree of impact attenuation.

In an embodiment, the first inflatable structure being provided in a folded and/or rolled form, the first plurality of parallel first air chambers not being inflated with air when in the folded and/or rolled form. The impact attenuating system may thus be in a compact form, allowing for easy handling and transport.

In an embodiment, the impact attenuating system further comprises a top layer covering at least part of the first plurality of parallel first air chambers for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over multiple parallel first air chambers of the first plurality of parallel first air chambers. Hereby, the impact is attenuated by multiple parallel first air chambers. This may provide for a more smooth landing upon impact. This allows impact attenuating system to better attenuate larger forces and pressures. This may alternatively or additionally also provide for a reduced risk of touching the ground surface under the impact attenuating system. The top layer may, by covering at least part of the first plurality of parallel first air chambers, be arranged for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over at least two parallel first air chambers of the first plurality of parallel first air chambers, such as over at least three or at least four parallel first air chambers..

In an embodiment, the impact attenuating system further comprises a top layer covering a first part of the first plurality of parallel first air chambers for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over multiple parallel first air chambers of the first plurality of parallel first air chambers, while a second part of the first plurality of parallel first air chambers is left uncovered. E.g., the top layer may not cover the first air chambers at the exterior side of the parallel, side-by-side arrangement of the first plurality of parallel first air chambers.

In embodiments, the top layer covers all the first plurality of parallel first air chambers for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over multiple parallel first air chambers of the first plurality of parallel first air chambers. Hereby, all first air chambers of the first plurality of parallel first air chambers and the impact may be spread until close to the edge of the impact attenuating system.

In embodiments, the top layer further provides the impact attenuating system with a substantially flat top impact surface. This may provide for an even more smooth landing upon impact and/or for a smooth driving surface when continuing driving on the top surface of the impact attenuating system after landing.

In an embodiment, the top layer is made of or comprises a technical coated fabric comprising TPU, PVC, EVA, PVC/PU blends and/or HDPE In embodiments, the top layer may be a layer of any suitable material, such as any relatively flexible air-impermeable material or semi-permeable material, such as a suitable canvas or another suitable textile, a suitable PVC-coated textile, a suitable plastic, a suitable thermoplastic rubber, PVC, polyurethane, polyethylene, silicone, ethylene vinyl acetate, HDPE, or another suitable thermoplastic polyurethane elastomer, or any other suitable material, a coated layer of one of these listed materials and a coating, e.g., a neoprene-coated fabric, or a laminate of at least one of these listed materials. A relatively flexible material, such as PVC-coated textile, may provide for a good landing characteristics when landing with, for example, a freestyle motorbike on a down-hill slope.

In other embodiments, the top layer may be a relatively stiff material. In embodiment, the top layer has a larger stiffness than the materials used for the air chambers. Hereby, the distribution over the impact in length and width over the inflatable structure(s) below the top layer may be further enhanced.

In embodiments, top layer may be a relatively stiff material that is also relatively smooth, allowing for good landing characteristics when landing with, for example, a freestyle bicycle with rubber tires with an appropriate profile on a down-hill slope. An example of a top layer with such characteristics is a top liner made from, what is commonly referred to as, “dump truck liner”. With such top layer, a smooth landing surface allowing to conveniently continue riding after the landing may be obtained.

In an embodiment, the top layer comprises or is a top sheet. The top sheet may have uniform characteristics in all directions. The top sheet may provide uniform characteristics in the length direction, corresponding to the major direction of motion across the top sheet when in use, and the perpendicular direction, corresponding to a direction perpendicular to the major direction of motion across the top sheet when in use.

In an embodiment, the top layer comprises or is a top liner. The top liner may have different characteristics in its length direction than in the direction perpendicular thereto. The top liner may provide first characteristics in the length direction, corresponding to the major direction of motion across the top sheet when in use, and different second characteristics in the perpendicular direction, corresponding to a direction perpendicular to the major direction of motion across the top sheet when in use.

The first and second characteristics may, for example, comprise a friction coefficient of the liner; the first characteristics may be associated with a lower friction in the length direction than the higher friction associated with the second characteristics.

Atop liner may be obtained from a roll of liner, e.g. a roll of more than 100 meters of liner.

The top liner may be cut from the roll.

The top liner may, e.g., be a liner usually referred to as “Resi” liner.

As an example, a 6mm HDPE “Resi” liner may be used.

In an embodiment, the impact attenuating system further comprises a second inflatable structure.

The second inflatable structure comprises a third sheet and a fourth sheet.

A first side of the third sheet is in contact with and connected to a first side of the fourth sheet along a second plurality of parallel second connection lines to form a second plurality of parallel second air chambers extending along a second direction.

The second plurality of parallel second air chambers is arranged on top of the first plurality of second parallel air chambers.

This provides a second inflatable structure, on top of the fist inflatable structure, wherein the second plurality of parallel second air chambers is inflatable to form a second plurality of parallel second tubular airbags arranged side-by-side in a second plane parallel to the first plane.

The combination of the first inflatable structure and the second inflatable structure allows additional design freedom and, for some applications, provides additional advantages than an impact attenuating system with only one first inflatable structure.

An impact attenuating system with one first inflatable structure may already adequately meet the technical requirements for some applications, such as for BMX freestyle.

For some applications, the use of a top layer covering at least part of the first inflatable structure may be used to better meet the technical requirements for some applications and/or to provide additional benefits.

When using a the first inflatable structure without a second inflatable structure, the top layer may be of a relatively stiff material, for example with a stiffness that allows a top layer of a length of 25 meters of more and a width of 25 meters or less to only easily to be rolled up on its long direction, for example for transport.

For some other applications, the use of a second inflatable structure op top of the first inflatable structure, with the second inflatable structure being arranged perpendicular to the first inflatable structure, may be preferred due to further improved performance, for example to provide a further improved impact attenuation when the sportsman uses a relative heavy sports equipment is used such as a freestyle motorbike.

When using a second inflatable structure op top of the first inflatable structure in combination with a top layer on top of the second inflatable structure and the first inflatable structure, the top layer may be less stiff than when using only a first inflatable structure; the top layer may then for example have a stiffness that allows the top layer to be foldable into a compact package for easy transport.

The third and/or fourth sheets may be impermeable to air, which may further be referred to as a third and fourth air-impermeable sheet. The third and/or fourth sheet may be semi-impermeable to air, which may further be referred to as a third and fourth air-semi-impermeable sheet. In an embodiment, the second direction is perpendicular to the first direction. Hereby, the second air chambers of the second inflatable structure are oriented at a 90 degree angle relative to the first air chambers of the first inflatable structure. Such arrangement may be beneficial for impact, landing and/or crossing behavior for some applications, for example for some specific freestyle sport and/or some specific location. Other applications may better benefit from other angular arrangements. Thus, in another embodiment, the second direction is parallel to the first direction; hereby, the second air chambers of the second inflatable structure are oriented at a 0 degree angle relative to the first air chambers of the first inflatable structure. In a again another embodiment, the second direction is at an angle in a range of 0 — 90 degrees to the first direction, such as for example at 30 degrees or 45 degrees.

In an embodiment, the second plurality of parallel second air chambers is inflated with air to form a second plurality of parallel second tubular airbags arranged side-by-side in a second plane parallel to the first plane. With both the first plurality of parallel first air chambers as well as the second plurality of parallel second air chambers being inflated with air, an efficient attenuating of an impact and/or an improved driving behavior when driving across the top surface of the impact attenuating system may be obtained.

In an embodiment, the first air chambers of the first inflatable structure extend in the width direction of the impact attenuating system and the second air chambers of the second inflatable structure extend in the length direction of the impact attenuating system. Hereby, the upper of the two inflatable structures has the air chambers extending in the length direction; where the length direction is the major direction of use, e.g., is the downhill direction on a landing slope, a suitable landing and/or riding surface may be provided.

In an embodiment, the impact attenuating system further comprises a top layer covering at least part of the second plurality of parallel second air chambers formed by the third and the fourth sheet for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over multiple parallel first second chambers of the second plurality of parallel second air chambers.

Hereby, an improved impact attenuation may be achieved, and a relatively thin impact attenuating system may be provided which nevertheless has a good impact attenuation; for example, a quite uniform degree of impact attenuation may be achieved irrespective of whether a person exercising e.g. freestyle BMX lands on a position on the top layer above a top of one of the second air chambers or above a connection line between two adjacent second air chambers.

As the impact is attenuated by multiple parallel second air chambers when using such top layer, this may provide for a more smooth landing upon impact.

This allows the impact attenuating system to better attenuate larger forces and pressures.

This may alternatively or additionally also provide for a reduced risk of touching the ground surface under the impact attenuating system.

The top layer may, by covering at least part of the second plurality of parallel second air chambers, be arranged for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over at least two parallel second air chambers of the second plurality of parallel second air chambers, such as over at least three or at least four parallel second air chambers.

In a further embodiment, the top layer covering at least part of the second plurality of parallel second air chambers formed by the third and the fourth sheet further provides the impact attenuating system with a substantially flat top impact surface.

In some embodiments, the substantially flat top impact surface is a flat top surface of the impact attenuating system.

In other embodiments, the substantially flat top impact surface has a height variation of less than 25%, for example less than 15%, for example less than 10%, for example less than 5% of the height of an second tubular airbag in the inflated state, where height variation is measured as the distance in the vertical plane between the vertical position of the top surface of the top layer on top of the second tubular air chamber and the vertical position of the top surface of the top layer in between two adjacent second tubular air chamber.

In embodiments, the top layer further covering at least part of the second plurality of parallel second air chambers formed by the third and the fourth sheet provides the impact attenuating system with a substantially flat top impact surface.

Examples of top layer materials were described above with reference to a top layer covering a first inflatable structure; the examples mentioned there may be also be used here.

According to another aspect, the invention provides a sports exercise area comprising a landing area and an air supply unit. The landing area comprising an impact attenuating system according to any of the preceding claims. The air supply unit being operable to provide air to the impact attenuating system for providing the landing area with an impact attenuating surface.

As the thickness of the impact attenuating system may be relatively thin compared to known systems, and the impact attenuating system may follow the structure of the underlying surface, the sports exercise are may thus be selectively operated between an exercising mode and a production mode, e.g., used during a competition and during the final exercising therefore, with quite similar moment of impact between the two modes. The system may hereby allow the sportsman to use the same take-off method and characteristics, such as power of take-off and rotational speed when jumping and preparing for landing. With known systems, the sportsman needs to adapt his take off method and characteristics due to a significant difference between moment of impact with and without known attenuation impact systems with a significant larger thickness, and/or the jumper needs to change the setup of the exercising area. With the sport area according to the invention, exercising when practicing may thus resemble exercising when competing.

In an embodiment, the landing area has a major driving direction, for example the direction of movement when landing, and - where the impact attenuating system has a top layer, the air chambers immediately below the top layer are arranged in parallel to the major driving direction, or - where the impact attenuating system has no top layer: the air chambers forming the upper surface are arranged in parallel to the major driving direction.

In an embodiment, the landing area comprises a varying slope and the impact attenuating system is at least arranged on the varying slope.

In an embodiment, the landing area comprises an edge and the impact attenuating system is at least arranged on the edge.

In an embodiment, the sports exercise area is arranged to be selectively operated between an exercising mode and a production mode, the air supply unit being arranged to provide air to the impact attenuating system in the exercising mode for providing the landing area with impact attenuating surface, the air supply unit being arranged to not provide air to the impact attenuating system in the production mode for providing the landing area without an impact attenuating surface.

In an embodiment, the air supply unit being operable to provide a continuous flow of air to the impact attenuating system for providing the landing area with an impact attenuating surface during use. In an embodiment, the air supply unit being operable to selectively provide air to the impact attenuating system for inflating the impact attenuating system to an inflated state for providing the landing area with an impact attenuating surface prior to use and to not provide air to the impact attenuating system during use, the impact attenuating system being arranged to maintain in the inflated state for providing the landing area with an impact attenuating surface during at least a predetermined time period, the predetermined time period being at least of a sufficient length for allowing an exercising session. E.g., the impact attenuating system may be arranged to maintain in the inflated state for providing the landing area with an impact attenuating surface during at least a predetermined time period in a range of 10 — 120 minutes, such as in a range of 10 — 60 minutes, such as in a range of 10 — 30 minutes.

According to yet another aspect, the invention provides a method of manufacturing a first inflatable structure for an impact attenuating system, the method comprising: - providing a first sheet, - providing a second sheet, - bringing a first side of the second sheet in contact with a first side of the first sheet along a first plurality of parallel first connection lines, - connecting the first side of the second sheet to the first side of the first sheet along a first plurality of parallel first connection lines to form a first plurality of parallel first air chambers extending along a first direction. The first plurality of parallel first air chambers is inflatable to form a first plurality of parallel first tubular airbags / elements arranged side-by-side in a first plane. In an embodiment, the first side of the first sheet is connected to the first side of the second sheet along the first plurality of parallel first connection lines using a plurality of lines of adhesive, a plurality of lines of glue, a plurality of glue dots arranged along a line, a plurality of welds, a plurality of seams, a plurality of stitched seams, and/or a plurality of heat seals. According to yet another aspect, the invention provides a method of manufacturing an impact attenuating system, the method comprises a method of manufacturing a first inflatable structure according to any embodiment, and the method further comprises:

- providing a top layer, - covering at least part of the first plurality of parallel first air chambers formed by the first sheet and the second sheet with the top layer, so as to provide the impact attenuating system with a substantially flat top impact surface.

The top layer me be a relatively stiff top layer. The top layer cooperates with the first inflatable structure to distributing an impact pressure applied to the upper exterior surface of the impact attenuating system over at least parts of multiple parallel first chambers of the first plurality of first second air chambers.

In an embodiment, the method further comprises: - prior to the covering of the at least part of the first plurality of parallel first air chambers with the top layer: inflating the first plurality of parallel first air chambers to form a first plurality of parallel first tubular airbags arranged side-by-side in a first plane.

According to yet another aspect, the invention provides a method of manufacturing an impact attenuating system, the method comprising the method of manufacturing a first inflatable structure according to any embodiment, and the method further comprising manufacturing a second inflatable structure, the manufacturing of the second inflatable structure comprising: - providing a third sheet, and - providing a fourth sheet, - bringing a first side of the third sheet being in contact with a first side of the fourth sheet along a second plurality of parallel second connection lines, - connecting the first side of the third sheet to a first side of the fourth sheet along a second plurality of parallel second connection lines to form a second plurality of parallel second air chambers extending along a second direction, - arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers with the second direction being perpendicular to the first direction.

The second plurality of parallel second air chambers is inflatable to form a second plurality of parallel second tubular airbags arranged side-by-side in a second plane parallel to the first plane. The method thus provides an impact attenuating system with the second inflatable structure arranged on top of the first inflatable structure, with, when inflated, the second plurality of parallel second tubular airbags of the second inflatable structure rotated with 90° relative to the first plurality of parallel first tubular airbags of the first inflatable structure.

In an embodiment, the method further comprises: - providing a top layer,

- covering at least part of the second plurality of parallel first air chambers formed by the third sheet and the fourth sheet with the top layer, so as to provide the impact attenuating system with an upper exterior surface arranged for distributing an impact pressure applied to the upper exterior surface of the impact attenuating system over multiple parallel second chambers of the second plurality of parallel second air chambers and/or so as to provide the impact attenuating system with a substantially flat top impact surface. The top layer me be a relatively stiff top layer or a relatively flexible top layer. The top layer cooperates with the first inflatable structure to distributing an impact pressure applied to the upper exterior surface of the impact attenuating system over at least parts of multiple parallel first chambers of the first plurality of first second air chambers. In an embodiment, the method further comprises: - prior to the covering of the at least part of the second plurality of parallel second air chambers with the top layer: inflating the second plurality of parallel first air chambers to form a second plurality of parallel second tubular airbags arranged side-by-side in a second plane.

BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter. In the drawings, Figures 1a — 1c, 2a — 2c and 3 schematically illustrate a method of manufacturing an impact attenuating system according to an embodiment and an impact attenuating system according to an embodiment, Figure 4 schematically illustrates an impact attenuating system according to an embodiment; during use, Figures 5a — 5e schematically show some details of some further embodiments, Figure 6 schematically show some details of embodiments, Figures 7a — 7c schematically illustrates some aspects of a further method of manufacturing an impact attenuating system according to a further embodiment; Figure 8 schematically illustrates an impact attenuating system according to such further embodiment, Figure 9 schematically shows a method of operation of an impact attenuating system according to an embodiment,

Figures 10a — 10b and 11a — 11d schematically illustrate various embodiments, and Figures 12a — 12b schematically illustrate embodiments of a sports exercise area an impact attenuating system according to an embodiment.

It should be noted that items which have the same reference numbers in different Figures, have the same or corresponding structural features and the same or corresponding functions, or are the same or corresponding signals. Where the function and/or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

DETAILED DESCRIPTION Throughout this document, the term “length” and “width” refer to a length and width dimension of a component, device or system as such. When a specific orientation is meant to be indicated by such a term, that is indicated explicitly or by reference to the use of the component, device or system when exercising sports.

Throughout this document, the term “length direction” and “width direction” refer to the direction along the length and along the width of a component, device or system as such. When a specific orientation is meant to be indicated by such a term, that is indicated explicitly or by reference to the use of the component, device or system when exercising sports.

Throughout this document the term “major direction” refers to the direction in which a user is moving over the system when exercising freestyle sports, e.g., the direction of riding a BMX bicycle when landing in a downhill direction when exercising tricks and moves. The term “perpendicular direction” refers to the direction in the plane of movement perpendicular to the major direction.

Throughout this document, any reference to a specific freestyle sports is only used for clarification and not intended to limit to the specific freestyle sports, unless the contrary is unambiguously implied by the context.

In the non-limiting examples below, sheets 101, 102, 201, 202 are described to be air-impermeable sheets. The sheets may alternatively be air-semi- impermeable sheets suitable for inflatable structures, such as used in known inflatable structures and such as sheets known to the skilled person.

Figures 1a — 1c, 2a — 2c and 3 schematically illustrate a method of manufacturing an impact attenuating system according to an embodiment and an impact attenuating system according to an embodiment. Figure 4 schematically illustrates an impact attenuating system 1 for attenuating impact =according to an embodiment during use, in particular upon impact of an object 99. The impact attenuating system 1 shown in Figure 4 comprises a first inflatable structure 14. The first inflatable structure 14 comprises a first air-impermeable sheet 101 and a second air-impermeable sheet 102. The first air-impermeable sheet 101 is connected to the second air-impermeable sheet 102 along a first plurality 103 of parallel first connection lines 103-1, 103-2, 103-2. More specifically, a first side 111 of the first sheet 101 is in contact with and connected to a first side 112 of the second sheet 102 along a first plurality 103 of parallel first connection lines 103-1, 103-2, 103-

3. Hereby, the first plurality 103 of parallel first connection lines 103-1, 103-2, 103-3 form a first plurality 104 of parallel first air chambers104-1, 104-2, 104-3 extending along a first direction D1.

The first side 111 of the first sheet 101 is connected to the first side 112 of the second sheet 102 along the first plurality of parallel first connection lines 103-1, 103-2, 103-3 using a plurality of lines of adhesive, a plurality of lines of glue, a plurality of glue dots arranged along a line, a plurality of welds, a plurality of seams, a plurality of stitched seams, and/or a plurality of heat seals.

The first sheet 101 is further in contact with and connected to the second sheet 102 along a plurality of enclosures lines 115-1, 115-2, 115-3, 115-4 enclosing the first plurality of parallel first air chambers 104-1, 104-2, 104-3 while to form at least one air supply chamber 120-1, 120-2 for distributing air from a first air inlet 120-0 to the first plurality of parallel first air chambers; reference is also made to Figure 9.

The plurality of enclosures lines comprising at least two enclosure lines 115- 1, 115-2 arranged perpendicular to the connection lines 103-1, 103-2, 103-3 and spaced apart from the ends of the connection lines as far as these do not form enclosure lines by at least a distance d115-1, d115-2 in a range of 10 — 100 cm, such as in a range of 20 — 80 cm, such as in a range of 20 — 60 cm, such as in a range of 30 — 40 cm, measured when the first plurality of parallel first air chambers are in a deflated state.

The first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 may be inflated with air to form a first plurality of parallel first tubular airbags 104-1, 104-2, 104-3 arranged side-by-side in a first plane substantially parallel to the surface of the underground below the first inflatable structure and substantially parallel to the top surface of the impact attenuating system. Figure 1c illustrate an inflation to a first degree, where all parallel first tubular airbags 104-1, 104-2, 104-3 have a substantial oval shape. Figure 3 shown a perspective illustration of the same.

The first sheet and the second sheet have dimensions which may be predetermined according to the intended use. The first sheet and the second sheet may have dimensions which allow a general use. The dimensions are indicated in Figure 2a.

The first sheet 101 may have a first sheet length 1101 in a range of 1 — 100 meters and a first sheet width b101 in a range of 1 — 100 meters, such as a first sheet length in a range of 5 — 100 meters and a first sheet width in a range of 2 — 40 meters such as a first sheet length in a range of 5 — 80 meters and a first sheet width in a range of 5 — 30 meters, such as a first sheet length in a range of 10 — 50 meters and a first sheet width in a range of 4 — 10 meters.

The second sheet 102 may have a second sheet length [102 equal to the first sheet length 1101 and a second sheet width b102 equal to the a first sheet width b101. Alternatively, the first and second sheet lengths and/or sheet widths may be different to allow for, e.g., some extra sheet at one or more sides of the inflatable structure for, e.g., handling and fixation.

The parallel first connection lines 103-1, 103-2, 103-3 of the first plurality 103 of parallel first connection lines may be spaced apart at a distance d113 {shown in Figures 1b, 2b and 2c) in a range of 10 — 100 cm, such as in a range of 20 — 80 cm, such as in a range of 20 — 60 cm, such as in a range of 30 — 40 cm, measured when the first plurality of parallel first air chambers are in a deflated state. When inflating, the spacing distance between the parallel first connection lines decreases, as shown in Figure 4, to an unloaded spacing d114-1 smaller than d113. When an object 99 impacts on the impact attenuating system 1 shown, at least the first air chambers below the area of impact reduce in height and their width d114-5 increases as their volume remains substantially constant. Also, if a top layer 110 is provided, the impact is distributed over multiple first air chambers 104-4, 104-5, 104-6 and the adjacent first air chambers 104-4, 104-6 also reduce in height and their width d114-4 increases. An impact on the impact attenuating system thus results in an harmonica effect of the first air chambers below and near the area of impact. This harmonica effect provides for an efficient and convenient impact absorption.

The impact attenuating system may be operated with an air supply unit 140, as shown in Figure 9. The first plurality of parallel first air chambers may be inflated using a continuous supply of air 121 to form a first plurality of parallel first tubular airbags 104-1, 104-2, 104-3 arranged side-by-side in a first plane substantially parallel to the surface of the underground below the first inflatable structure and substantially parallel to the top surface of the impact attenuating system. For easy reference, the same reference signs are used for the partially or fully inflated first tubular airbags 104- 1, 104-2, 104-3 as for the parallel first air chambers 104-1, 104-2, 104-3 formed before being connected to an air supply unit.

The first inflatable structure 14 may, when not inflated, be provided in a folded and/or rolled form.

Figure 4 shows an embodiment of the impact attenuating system comprising a first inflatable structure 14 and a top layer 110. The top layer 110 covers the first plurality 104 of parallel first air chambers for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over multiple parallel first air chambers 104-4, 104-5 of the first plurality 104 of parallel first air chambers. The top layer 110 may alternatively covers part of the first plurality 104 of parallel first air chambers, for example as shown in Figure 6.

According to embodiments, an impact attenuating system may comprise a single first inflatable structure 14 and an air inlet device. Other embodiments of an impact attenuating system, described below, may additionally comprise a top layer 110 and/or a second inflatable structure 24.

A method to manufacture a first inflatable structure 14 for an impact attenuating system 1 is described with reference to Figures 1a — 3. The method comprises providing a first air-impermeable sheet 101 and providing a second air- impermeable sheet 102, as shown in Figure 1a. Example dimensions are given above. Figure 1b and 2b illustrates that the method further comprises bringing a first side 112 of the second sheet in contact with a first side 111 of the first sheet along a first plurality of parallel first connection lines 103-1, 103-2, 103-3 spaced at a distance d113 and connecting the first side of the second sheet to the first side of the first sheet along a first plurality of parallel first connection lines 103-1, 103-2, 103-3 to form a first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 extending along a first direction D1. As shown in Figure 1c and 3, the first plurality of parallel first air chambers 104 being inflatable to form a first plurality of parallel first tubular airbags 104 arranged side-by-side in a first plane.

The first side 111 of the first sheet 101 may be connected to the first side 112 of the second sheet 102 along the first plurality 103 of parallel first connection lines 103-1, 103-2, 103-2 using a plurality of lines of adhesive, a plurality of lines of glue, a plurality of glue dots arranged along a line, a plurality of welds, a plurality of seams, a plurality of stitched seams, and/or a plurality of heat seals.

A method of manufacturing an impact attenuating system may comprise the method of manufacturing a first inflatable structure as described above, providing an air inlet system for applying air to the first inflatable structure.

In another embodiment, a method of manufacturing an impact attenuating system comprises the method of manufacturing a first inflatable structure 14 as described above and further comprises providing a top layer 110 and covering at least part of the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 formed by the first air-impermeable sheet 101 and the second air-impermeable sheet 102 with the top layer 110.

This provides the impact attenuating system with an upper exterior surface arranged for distributing an impact pressure applied to the upper exterior surface of the impact attenuating system 1 over multiple parallel first chambers 104-4, 104-5, 104-6 of the first plurality 104 of parallel first air chambers. Additionally or alternatively, this may provide the impact attenuating system with a substantially flat top impact surface.

Figures 5a — 5e schematically shows illustrative examples indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 and connected. Figure 6 schematically shows an illustrative example of another arrangement of the cover layer 110 on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 and the connection thereto, where the cover layer is not attached to the outer first air chambers, but one air chamber inward from either end of the side-by-side arrangement.

Figure 5a schematically shows an illustrative example indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 when inflated at un unloaded spacing d114. Figure 5a shows the top layer 110 being arranged over the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5a schematically shows that two sides of the top layer 110 are connected to anchors 152 in the ground 10 via ropes 151 extending through holes in the top layer (not shown) and hooks 153 fixed in the anchors 152. Alternative connections between the top layer 110 and the anchors 152 are also possible, e.g. with strips of top-sheet material replacing ropes 151.

Figure 5b schematically shows another illustrative example indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5b shows the top layer 110 being arranged over the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5b schematically shows that two ends of the top layer 110 are connected to the ends of the first and/or the second sheet 101, 102 via ropes 161 extending through holes (not shown) in the top layer and through holes (now shown) in the ends of the first and/or the second sheet 101, 102. The holes in the ends of the first and/or the second sheet 101, 102 may, .e.qg., be formed in parts of the first and/or the second sheet 101, 102 extending outside the enclosure lines.

Figure 5c schematically shows another illustrative example indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Therein, the top layer 110 is connected to anchors 152 in the ground 10 in a similar manner as in Figure 5a using ropes 171 extending through holes in the top layer (not shown) and hooks 153 fixed in the anchors 152. Further, ropes 172 extending through or connected to two ends of the top layer 110 are connected to ropes 171. Figure 5d schematically shows another illustrative example indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5d shows the top layer 110 being arranged over the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5d schematically shows that the top layer 110 is attached to the top areas of outer first parallel air chambers 104-1, 104-3 of the plurality of first parallel air chambers 104-1, 104-2, 104-3 using connections 110-g. Connections 110-g may e.g. be made using adhesives or with stitching.

Figure 5e schematically shows another illustrative example indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5e shows the top layer 110 being arranged over the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. Figure 5e schematically shows that the top layer 110 is attached to the upper side areas of the two outer first parallel air chambers 104-1, 104-3 of the plurality of first parallel air chambers 104-1, 104-2, 104-3 using connections 110-h. Connections 110-h may e.g. be made using adhesives or with stitching.

Figure 6 schematically shows another illustrative example indicating how the top layer 110 may be arranged on the first plurality 104 of parallel first air chambers 104-1, 104-2, ...., 104-N-1, 104-N. Figure 6 shows the top layer 110 being arranged over a subset 104a of the first plurality 104 of parallel first air chambers 104-1, 104-2, .... 104-N-1, 104-N. The subset 104a comprises all but the outer first air chambers of the first plurality 104 of parallel first air chambers 104-1, 104-2, .... 104-N-1, 104-N, i.e.

the subset 104a comprises parallel first air chambers 104-2, .... 104-N-1. Figure 6 schematically shows that the top layer 110 is attached to the upper side areas of the two outer first parallel air chambers 104-2, 104-N-1 of the subset 104a using connections 110-j. Connections 110-h may e.g. be made using adhesives or with stitching.

Figures 7a — 7c and 8 schematically illustrate a method of manufacturing an another impact attenuating system according to another embodiment and an impact attenuating system according to the other embodiment.

Figure 8 schematically shows an impact attenuating system 2 comprising a first inflatable structure 14 and a second inflatable structure 24, in an inflated state.

Figure 8 further shows that the impact attenuating system 2 comprises a top layer 210; embodiments of the impact attenuating system 2 may however also be provided without such top layer 210.

The first inflatable structure 14 may be similar as described with reference with Figure 4. Similar to what was described with reference to Figure 2a — 2c and Figure 4, the first inflatable structure 14 comprises a first air-impermeable sheet 101 and a second air-impermeable sheet 102. The first air-impermeable sheet 101 is connected to the second air-impermeable sheet 102 along a first plurality 103 of parallel first connection lines 103-1, 103-2, 103-2. More specifically, a first side 111 of the first sheet 101 is in contact with and connected to a first side 112 of the second sheet 102 along a first plurality 103 of parallel first connection lines 103-1, 103-2, 103-

Similar to what was described with reference to Figure 2c and Figure 4, the first sheet 101 is further in contact with and connected to the second sheet 102 along a plurality of enclosures lines 115-1, 115-2, 115-3, 115-4 enclosing the first plurality of parallel first air chambers 104-1, 104-2, 104-3 while to form at least one air supply chamber 120-1, 120-2 for distributing air from a first air inlet 120-0 to the first plurality of parallel first air chambers.

Similar to what was described with reference to Figure 4, the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 may be inflated with air to form a first plurality of parallel first tubular airbags 104-1, 104-2, 104-3 arranged side-by-side in a first plane substantially parallel to the surface of the underground below the first inflatable structure and substantially parallel to the top surface of the impact attenuating system.

Similar to what was described with reference to Figure 2a and Figure 4, the first sheet and the second sheet of the first inflatable structure 14 have dimensions which may be predetermined according to the intended use.

The first sheet and the second sheet may have dimensions which allow a general use.

The dimensions are indicated in Figure 2a.

The first sheet 101 may have a first sheet length 1101 in a range of 1 — 100 meters and a first sheet width b101 in a range of 1 — 100 meters.

The second sheet 102 may have a second sheet length 1102 equal to the first sheet length 1101 and a second sheet width b102 equal to the a first sheet width b101. The second inflatable structure 24 has a similar construction, as is shown in Figure 7a — 7c and Figure 8. The second inflatable structure 24 comprises a third air- impermeable sheet 201 and a fourth air-impermeable sheet 202. As schematically shown in Figure 7b, a first side 211 of the third sheet 201 is in contact with and connected to a first side 212 of the fourth sheet 202 along a second plurality 203 of parallel second connection lines 203-1, 203-2, 203-3 to form a second plurality 204 of parallel second air chambers 204-1, 204-2, 204-3 extending along a second direction D2. Such impact attenuating system 2, comprising a second inflatable structure 24 on top of a first inflatable structure 14, where the second inflatable structure 24 is arranged with the parallel second air chambers in the major direction of driving across the impact attenuating system 2, may show very good performance for driving across with, e.g., a freestyle motorbike, a freestyle BMX or freestyle snowboard.

As shown in Figure 7b, similar to what was described with reference to Figure 2c and Figure 4, the third sheet 201 is further in contact with and connected to the second sheet 202 along a plurality of enclosures lines 215-1, 215-2, 215-3, 215-4 enclosing the second plurality 204 of parallel second air chambers 204-1, 204-2, 204-3 while to form at least one second air supply chamber 220-1, 220-2 for distributing air from a second air inlet 220-0 to the second plurality 204 of parallel second air chambers.

Similar to what was described with reference to Figure 4, the second plurality 204 of parallel second air chambers 204-1, 204-2, 204-3 may be inflated with air to form a second plurality of parallel first tubular airbags 204-1, 204-2, 204-3 arranged side-by-side in a second plane substantially parallel to the top surface of the impact attenuating system, as shown in Figure 7c.

The third sheet 201 and the fourth sheet 202 have dimensions which may be predetermined according to the intended use and in relation to the dimensions of the first sheet and 101 the second sheet 102. The first, second, third and fourth sheet may have dimensions which allow a general use. The dimensions of the third sheet 201 and fourth sheet 202 are indicated in Figure 7a. For the dimensions of the first sheet 101 and second sheet 102, reference is made to Figure 2a.

The third sheet 201 may have a third sheet length [201 in a range of 1 — 100 meters and a third sheet width b201 in a range of 1 — 100 meters, such as a third sheet length in a range of 5 — 100 meters and a third sheet width in a range of 2 — 40 meters such as a third sheet length in a range of 5 — 80 meters and a third sheet width in a range of 5 — 30 meters, such as a third sheet length in a range of 10 — 50 meters and a third sheet width in a range of 4 — 10 meters.

The fourth sheet 202 may have a fourth sheet length 1202 equal to the third sheet length 1201 and a fourth sheet width b202 equal to the a third sheet width b201. Alternatively, the third and fourth sheet lengths and/or sheet widths may be different to allow for, e.g., some extra sheet at one or more sides of the inflatable structure for, e.g., handling and fixation.

The parallel second connection lines 203-1, 203-2, 203-3 of the second plurality 203 of parallel second connection lines may be spaced apart at a distance d213 (shown in Figures 7) in a range of 10 — 100 cm, such as in a range of 20 — 80 cm, such as in a range of 20 — 80 cm, such as in a range of 30 — 40 cm, measured when the second plurality of parallel second air chambers are in a deflated state. Figure 7c shows that the distance between adjacent second connection lines is reduced to an unloaded spacing d214-1 when inflated to be used.

Thus, in the impact attenuating system shown in Figure 8, the second plurality 204 of parallel second air chambers of the impact attenuating system 24 is arranged on top of the first plurality 104 of first parallel air chambers. The second direction D2 is perpendicular to the first direction D1, i.e., the second plurality 204 of parallel second air chambers is rotated by 90 degrees relative to the first plurality 104 of first parallel air chambers. When inflated with air, the second plurality 204 of parallel second air chambers forms a second plurality of parallel second tubular airbags arranged side-by-side in a second plane parallel to the first plane formed by the first plurality of parallel first tubular airbags.

The impact attenuating system 24 shown in Figure 8 further comprises a top layer 210 covering at least part of the second plurality 204 of parallel second air chambers formed by the third air-impermeable and the fourth air-impermeable sheet for distributing an impact pressure applied to an upper exterior surface of the impact attenuating system over multiple parallel second chambers of the second plurality of parallel second air chambers. In an example of the impact attenuating system 2 shown in Figure 8, the impact attenuating system 2 provides for an impact area of 6 meters wide and 20 meters long, intended for landing and drive-through when exercising freestyle motorcycling. Hereto: - the first inflatable structure 14 comprises a first plurality 104 of 40 parallel first air chambers extending in the width direction of approximately 50 cm diameter d114, obtained from a first and second sheet 101, 102 both of a length 1101, [102 approximately 35 meters long and a width b101, b102 of approximately 7 meters wide, stitched together using a spacing s113 between adjacent connection lines 103 of approximately 80 cm; - the second inflatable structure 24 is arranged on top of the first inflatable structure 14 and comprises a second plurality 204 of 12 parallel second air chambers extending in the length direction of approximately 50 cm diameter d214, obtained from a third and fourth sheet 201, 202 both of a length 1201, 1202 approximately 21 meters long and a width b201, b202 of approximately 10 meters wide, stitched together using a spacing s213 between adjacent connection lines 213 of approximately 80 cm; - the top sheet 210 is arranged to cover the second inflatable structure and to provide connection holes for connecting the top sheet to anchors in the ground.

Figure 9 schematically shows a method of operation of an impact attenuating system 500 according to an embodiment. The impact attenuating system 500 comprises a first inflatable structure 14. The first inflatable structure 14 comprises a first air-impermeable sheet 101 and a second air-impermeable sheet 102. A first side 111 of the first sheet 101 is in contact with and connected to a first side 112 of the second sheet 102 along a first plurality 103 of parallel first connection lines 103-1, 103- 2, 103-3 to form a first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 extending along a first direction D1. The first sheet 101 is further in contact with and connected to the second sheet 102 along a plurality of enclosures lines 115-1, 115-2, 115-3, 115-4 enclosing the first plurality of parallel first air chambers 104-1, 104-2, 104- 3 while to form at least one air supply chamber 120-1, 120-2 for distributing air from a first air inlet 120-0 to the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3. An air supply unit 140 is connected via an air connection 130 to first air inlet 120-0. The air supply unit 140 attracts air from the environment and supplies the air via the air connection 130 to the first air inlet 120-0, from where it is distributed to the first plurality 104 of parallel first air chambers 104-1, 104-2, 104-3 via the at least one air supply chamber 120-1, 120-2 as indicated by the open arrows. The construction of the inflatable structure itself thus provides for distribution as the connection lines 103-2, 103-3, as far as these do not also form the outer wall of the airbag, stop before the outer walls 115-1, 115-2 where air supply channels 120-1, 120-2 are formed on either side of the tubular air bags. So, there is no need for additional air supply and air connections on the exterior of the inflatable structure, as is the usual case for many known airbag systems such as for example for a kite bladder and its connections.

In embodiments, the air supply unit 40 is operated to continuously supply air during use of the impact attenuating system to provide for a constant air pressure in the first inflatable structure 14 while it is used for exercising sports. In other embodiments, where the first inflatable structure 14 can maintain its pressure after being inflated for at least an required minimum time, such as a duration of an exercising session, the air supply unit 40 is only operated to supply air for inflating the first inflatable structure 14 prior to use and first air inlet 120-0 or the air connection 130 may comprises a valve (not shown) allowing to maintain pressure when the supply unit 40 is not supplying air.

Thus, in exemplary embodiments, the supply unit 40 provides, during use, for a continuous supply of air to the tubular air bags via the air supply channels 120-1, 120-2. In alternative embodiments, the supply unit 40 provides, prior to use, air to the tubular air bags to fill them with air where the system is sufficiently air tight to keep a sufficient amount of air in all the tubular air bags for a sufficient amount of use time, i.e., to keep it inflated without continuously supplying air. In such alternative embodiments, the blower may be detached after the system is filled and a valve may be provided in the air inlet 120-0 or air connection 130 to prevent air flowing out of the system after it has been inflated In the embodiments describes above, the parallel connection lines were shown as straight lines. Figures 10a and 10b schematically illustrate alternative embodiments of the parallel connection lines.

Figure 10a schematically illustrates that the parallel first connection lines 103-2’, 103-3’ of the plurality 103’ of parallel first connection lines may alternatively wobble around corresponding parallel first connection line directions 123-2’ all extending along first direction D1. The shape of the wobbling line may, e.g., have a continuous first derivative. The shape of the wobbling line may, e.g., have a continuous first and second derivative. The shape of the wobbling line may e.g. correspond to a sine-wave shape. The wobbles of adjacent connection lines are shown to be in-phase Alternative embodiments with the wobbles of adjacent connection lines being in opposite phase or non-synchronized are also possible. Figure 10b schematically illustrates that the parallel first connection lines 103-2”, 103-3” of the plurality 103” of parallel first connection lines may alternatively zigzag around corresponding parallel first connection line directions 123-2’. Such zigzag may also be referred to as sawtooth. The shape of the zig-zag line may, e.g., be composed of first straight line sections 103s1 and second straight line sections 103s2 at respective angles B1 and B2 relative to the first direction D1. For example, first straight line sections 10351 and second straight line sections 103s2 may have equal lengths and the first straight line sections 10351 arranged at an angle B1 in a range of 10-60 degrees, such as in a range of 10-45 degrees, such as in a range of 10-30 degrees, and the second straight line sections 103s2 may be arranged at an angle B2 = - B1. An another example example, first straight line sections 103s1 are shorter than the second straight line sections 103s2, the first straight line sections 103s1 arranged at an angle B1 in a range of 10-75 degrees, such as in a range of 10-60 degrees, such as in a range of 10-30 degrees, and the second straight line sections 103s2 may be arranged at an angle B2 smaller than the absolute angle B1. The zigzag line may have rounded edges between the first and second straight line sections. The zigzags of adjacent connection lines are shown to be in-phase. Alternative embodiments with the zigzags of adjacent connection lines being in opposite phase or non-synchronized are also possible.

From the above, the skilled person may appreciate that other shapes can be used for the connection lines in further alternative embodiments.

In embodiments with a second inflatable structure having parallel second connection lines, similar alternative shapes may be used for the parallel second connection lines as described above for the parallel first connection lines. Further, the parallel first connection lines and the parallel second connection lines may be different. In a non-limiting example, the parallel first connection lines are wobbling and the parallel second connection lines are straight.

In the embodiments describes above, the plurality 115 of enclosure lines were shown as straight lines. Figure 10b illustrates alternative embodiments of a plurality 115’ of enclosures lines. A subset of the plurality 115’ of enclosures lines shown in Figure 10b are not straight, but have a zig-zag shape, similar to the connection lines 103-2” shown in Figure 10b. In the example show, the enclosures lines 115-3" and 115-4’ extending substantially in parallel to the connection lines 103”

also have a zigzag shape. In the example shown, the zigzags of the enclosure lines 105-3’ and 105-4’, i.e., the ones parallel to the connection lines, are shown with the same period and phase as the connection lines. However, they may alternatively be in opposite phase of non-synchronized. Also, the periods of the zigzag of the enclosure lines and of the connection lines may be different. The skilled person may appreciate that other shapes can be used for the enclosure lines in further alternative embodiments.

In the embodiments of the impact attenuating system 2 with a second inflatable structure 24 on top of a first inflatable structure 14, and in some further embodiments covered with a cover layer 210, describes above -for example with reference to Figure 8, the second inflatable structure 24 was described as being arranged perpendicular on top of the first inflatable structure 14. Figures 11a - 11d schematically illustrate alternative embodiments with different arrangements of the two inflatable structures 14, 24, where the , the second inflatable structure 24 was described as being arranged perpendicular on top of the first inflatable structure 14 is various exemplary angles. It is further noted that additional inflatable structures could be provided to form an impact attenuating system with three or even more inflatable structures stacked on top of each other.

Figure 11a schematically illustrates the arrangement of the first inflatable structure 14 and the second inflatable structure 24 in an embodiment of an impact attenuating system. The first inflatable structure 14 has, similar as described, above a first plurality of parallel first air chambers extending along a first direction D1. The second inflatable structure 24 has, similar as described above, a second plurality of parallel second air chambers extending along a second direction D2. The second direction D2 is at an angle a relative to the first direction D1. In this document, this may also be indicated as “the second inflatable structure is arranged at an angle a to the first inflatable structure” or with similar terminology.

Figure 11b schematically illustrates an embodiment of the an impact attenuating system wherein the second direction D2 is at an angle indicated as a90 relative to the first direction D1, where a90 = 90 degrees The second plurality of parallel second air chambers is thus arranged perpendicular to the first plurality of parallel second air chamber. In this document, this may also be indicated as “the second inflatable structure is arranged perpendicular to the first inflatable structure” or with similar terminology.

Figure 11c schematically illustrates an embodiment of the an impact attenuating system wherein the second direction D2 is at an angle indicated as a00 relative to the first direction D1, where a00 = 0 degrees The second plurality of parallel second air chambers is thus arranged parallel to the first plurality of parallel second air chamber. In this document, this may also be indicated as “the second inflatable structure is arranged parallel to the first inflatable structure” or with similar terminology.

Figure 11d schematically illustrates an embodiment of the an impact attenuating system wherein the second direction D2 is at an angle indicated as a45 relative to the first direction D1, where a45 = 45 degrees The second plurality of parallel second air chambers is thus arranged at a 45 degrees angle to the first plurality of parallel second air chamber. In this document, this may also be indicated as “the second inflatable structure is arranged diagonal to the first inflatable structure” or with similar terminology.

The second plurality of parallel second air chambers may alternatively be thus arranged at other suitable angles to the first plurality of parallel second air chambers. For example, an angle of a = 30 degrees may be used.

Figures 12a — 12b schematically illustrate embodiments of a sports exercise area comprising an impact attenuating system according to an embodiment.

Figure 12a schematically illustrates an embodiment of a sports exercise area 510 comprising an impact attenuating system 501 according to an embodiment. The example may for example be a freestyle motorbike area. The sports exercise area 510 comprises a jump ramp 511 with a jump surface 513, and a landing ramp 516 comprising a landing area 514, 515. The landing area 514, 515 comprises a varying slope: a first, top part 514 of the landing area has a major convex slope and a second, lower part 515 of the landing area has a major concave slope.

The landing area 514, 515 comprises an impact attenuating system 501 according to an embodiment. The impact attenuating system 501 is arranged on the varying slope 514, 515. The sport exercise are also comprises an air supply unit (not shown). The air supply unit is operable to provide air to the impact attenuating system 501 for providing the landing area with an impact attenuating surface.

The landing area 514, 515 may comprise an impact attenuating system 501 according to an embodiment as shown in Figure 8. The impact attenuating system 501 may thus have a first inflatable structure 14 comprising first air chambers in a first direction D1, corresponding to the width direction, and a second inflatable structure 24 comprising second air chambers in a second direction D2, corresponding to the length direction, corresponding to the major direction of movement when moving down the slope of landing area 514, 515. The impact attenuating system 501 may have a top layer 210. An alternative landing area 514, 515 may comprise an impact attenuating system 501 according to an embodiment as shown in any one of Figure 4 — 6. The impact attenuating system 501 may thus have a first inflatable structure 14 comprising first air chambers in a direction D2, corresponding to the length direction, corresponding to the major direction of movement when moving down the slope of landing area 514, 515. The impact attenuating system 501 may have a top layer 110. When a relatively stiff top layer is used, an impact attenuating system with only a first inflatable structure and a top layer may already provide adequate performance.

According to an example, the sports exercise area 510 shown in Figure 12a is arranged to be selectively operated between an exercising mode and a production mode.

The air supply unit is arranged to provide air to the impact attenuating system in the exercising mode for providing the landing area with impact attenuating surface, while the air supply unit is arranged to not provide air to the impact attenuating system in the production mode for providing the landing area without an impact attenuating surface.

When exercising, a motorbike driver riding a freestyle motorbike accelerates onthe jump ramp 511 to reach a suitable speed to jump from the jump surface 513 and then perform any tricks while being in the air and before landing on the landing area 514, 515 of the landing ramp 518. If the jump is unexpectedly short, he may land on the first, top part 514 of the landing area.

If the jump is optimally executed, he may land on the part of the landing area with its transition from the major convex slope to the major concave slope of the second, lower part 515, or beyond that.

Due to the impact and surface performance of the impact attenuating system 501, he may continue to drive downward on the landing area 514, 515 on a relatively safe and soft surface.

In case the tricks fail and the biker lands out of balance, the impact and surface performance of the impact attenuating system 501 may often still allow him to continue driving.

If the trick does not succeed, he may fall and land on a safe impact surface of the impact attenuating system 501. Ramps 516 and/or 516 could be a natural ramp, e.g., a shaped snow slope.

The ramp could alternatively be an artificial ramp, e.g., a man-made construction of for example concrete, metal, wood and/or any other suitable material(s). The ramp could alternatively be an inflatable ramp that can be setup almost anywhere.

The impact attenuating system in combination with an inflatable ramps may be particularly cost effective, mobile and ideal for setting up at events and competitions.

Figure 12b schematically illustrates an embodiment of a sports exercise area 520 comprising an impact attenuating system 502 according to an embodiment. The example may for example be a freestyle biking area. The sports exercise area 520 comprises a shaped jumping hill 521 with a downhill part 522 and a jump surface 523, and a shaped landing hill 526 comprising a landing area 524, 525. The landing area 524, 525 comprises a varying slope: a first, top part 524 of the landing area may start off horizontally and has a major convex slope and a second, lower part 525 of the landing area has a major concave slope.

The landing area 524, 525 comprises an impact attenuating system 501 according to an embodiment. The impact attenuating system 502 is arranged on the varying slope 524, 525. The sport exercise are also comprises an air supply unit (not shown). The air supply unit is operable to provide air to the impact attenuating system 501 for providing the landing area with an impact attenuating surface.

The landing area 524, 525 may comprise an impact attenuating system 502 according to an embodiment as shown in Figure 8. The impact attenuating system 501 may thus have a first inflatable structure 14 comprising first air chambers in a first direction D1, corresponding to the width direction, and a second inflatable structure 24 comprising second air chambers in a second direction D2, corresponding to the length direction, corresponding to the major direction of movement when moving down the slope of landing area 524, 525. The impact attenuating system 501 may have a top layer 210.

An alternative landing area 524, 525 may comprise an impact attenuating system 502 according to an embodiment as shown in any one of Figure 4 — 6. The impact attenuating system 502 may thus have a first inflatable structure 14 comprising first air chambers in a direction D2, corresponding to the length direction, corresponding to the major direction of movement when moving down the slope of landing area 524, 525. The impact attenuating system 502 may have a top layer 110. When a relatively stiff top layer is used, an impact attenuating system with only a first inflatable structure and a top layer may already provide adequate performance. In some embodiments and for some applications, an impact attenuating system with only a first inflatable structure may already be sufficient to accommodate for the needs of the sportsman.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments. For example, the sheets 101, 102, 201, 202 may have different shapes than the rectangular shapes mentioned in the description. E.g., the sheets may have rounded corners, have a oval shape, a trapezium shape, any other suitable shape; for such sheets, the terms length and width may relate to the length and width of the smallest rectangle that can enclose the shape. The distance between adjacent first connection lines may be different from the distance between adjacent second connection lines. Distance between adjacent connection lines within a single inflatable structure may all be the same; alternatively, the distance between connection lines may vary within an inflatable structure such as to provide, for example, different diameter air chambers at various heights along a landing area on a slope. Other embodiments of the impact attenuating system may comprise three or more inflatable structures on top of each other. More than one air inlets may be provided on a single inflatable structure. More than one top layer may be provided.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

Conclusions

An impact attenuation system (1) for attenuating impact on a landing area (514, 515), the impact attenuation system comprising a first inflatable structure (14), the first inflatable structure (14) comprising: - a first cloth (101), and - a second fabric (102), - wherein a first side (111) of the first fabric (101) is in contact and connected to a first side (112) of the second fabric (102) along a first plurality (103 ) of parallel first connecting lines (103-1, 103-2, 103-3) to form a first plurality (104) of parallel first air chambers (104-1, 104-2, 104-3) extending in a first direction (D1).

The impact mitigation system of claim 1, wherein the first side of the first fabric is connected to the first side of the second fabric along the first plurality of parallel first connecting lines (103-1, 103-2, 103-3) using a a plurality of lines of adhesive, a plurality of lines of glue, a plurality of glue dots arranged along a line, a plurality of welds, a plurality of seams, a plurality of stitched seams, and/or a plurality of heat seals.

The impact mitigation system of any preceding claim, wherein the first fabric (101) further contacts and connects to the second fabric (102) along a plurality of containment lines (115-1, 115-2, 115-3, 115 -4) enclosing the first plurality of parallel first air chambers (104-1, 104-2, 104-3) to form at least one air supply chamber (120-1, 120-2) for diffusing air from a first air supply ( 120-0) to the first plurality of parallel first air chambers.

An impact attenuation system according to any preceding claim, wherein the plurality of containment lines comprises at least two containment lines (115-1, 115-2), arranged perpendicular to the connecting lines (103-1, 103-2, 103-3) and to spaced from the ends of the connecting lines insofar as they do not form boundary lines by at least a distance (d115-1, d115-2) in a range of 10 - 100 cm, for example in a range of 20 - 80 cm,

e.g. in a range of 20 - 60 cm, e.g. in a range of 30 - 40 cm, measured when the first plurality of parallel first air chambers are in a deflated condition.

The impact attenuation system of any preceding claim, wherein at least a portion of the first plurality of parallel first connecting lines (103-1, 103-2, 103-3) are straight lines, wobbly lines or zigzag lines.

Impact mitigation system according to any one of the preceding claims, wherein the first fabric (101) has a first fabric length (1101) in a range of 1-100 meters and a first fabric width (b101) in a range of 1-100 meters, for example a first fabric length in a range of 5 - 100 meters and a first fabric width in a range of 2 - 40 meters, for example a first fabric length in a range of 5 - 80 meters and a first fabric width in a range of 5 - 30 meters, for example a first fabric length in a range of 10 - 50 meters and a first fabric width in a range of 4 - 10 meters.

An impact attenuation system according to any preceding claim, wherein the parallel first connection lines (103-1, 103-2, 103-3) of the first plurality (103) of parallel first connection lines (103) are spaced (d113) from each other placed in a range of 10 - 100 cm, e.g. in a range of 20 - 80 cm, e.g. in a range of 20 - 60 cm, e.g. in a range of 30 - 40 cm, measured when the first plurality of parallel first air chambers be in a deflated state.

The impact mitigation system of any preceding claim, wherein the first plurality (104) of parallel first air chambers (104-1, 104-2, 104-3) is inflated with air around a first plurality of parallel first tubular airbags (104- 1, 104-2, 104-3) arranged side by side in a first plane substantially parallel to the impact surface.

The impact mitigation system of claim 8, wherein the first plurality of parallel first air chambers are inflated using a continuous supply of air to form a first plurality of parallel first tubular airbags arranged side by side in a first plane substantially parallel to the impact surface .

An impact attenuation system according to any one of claims 1 to 7,

wherein the first inflatable structure is provided in a collapsed and/or coiled form, the first plurality of parallel first air chambers being uninflated in the collapsed and/or coiled form.

The impact mitigation system of any preceding claim, further comprising a topsheet (110) covering at least a portion of the first plurality (104) of parallel first air chambers to distribute an impact pressure applied to an upper outer surface of the impact mitigation system over a plurality of parallel first air chambers. air chambers (104-4, 104-5) of the first plurality (104) of parallel first air chambers.

An impact mitigation system (2) according to any one of claims 1 to 10, further comprising a second inflatable structure (24), the second inflatable structure comprising: - a third sheet (201), and - a fourth sheet (202).

- wherein a first side (211) of the third fabric (201) is in contact and connected to a first side (212) of the fourth fabric (202) along a second plurality (203) of parallel second connecting lines (203-1 , 203-2, 203-3) to form a second plurality (204) of parallel second air chambers (204-1, 204-2, 204-3) extending in a second direction (D2), the second plurality (204) of parallel second air chambers is arranged on top of the first plurality (104) of first parallel air chambers.

The impact attenuation system of claim 12, wherein the second direction (D2) is perpendicular to the first direction (D1).

The impact mitigation system of claim 12, wherein the second direction (D2) is parallel to the first direction (D1).

The impact mitigation system of claim 12, wherein the second direction (D2) is 45 degrees to the first direction (D1).

The impact attenuation system of any preceding claim, wherein at least a portion of the second plurality of parallel second connecting lines (203-1, 203-2, 203-3) are straight lines, wobble lines or zigzag lines.

The impact mitigation system of any one of claims 12 to 16, wherein the second plurality (204) of parallel second air chambers 1s inflates with air to form a second plurality of parallel second tubular airbags arranged side by side in a second plane parallel to the first plane.

The impact attenuation system of any one of claims 12 to 17, further comprising a topsheet (210) comprising at least a portion of the second plurality (204) of parallel second air chambers formed by the third fabric (201) and the fourth fabric (202). covered to distribute an impact pressure applied to an upper outer surface of the impact mitigation system among a plurality of parallel second chambers of the second plurality of parallel second air chambers.

The impact attenuation system of claim 11 or 18, wherein the top layer (110; 210) provides the impact attenuation system with a substantially flat top impact surface.

A sports practice area (510) comprising a landing area (514, 515} and an air supply unit (140), the landing area (514, 515) comprising an impact mitigation system (1; 2) according to any preceding claim, and wherein the air supply unit ( 140) is operable to supply the impact attenuation system with air to provide the landing area with an impact attenuation surface.

The sports practice area (510) of claim 20, wherein the landing area (514, 515) comprises an alternating slope and the impact mitigation system is adapted to the alternating slope.

The sports practice area (510) according to any one of claims 20 to 21, wherein the sports practice area 1s is directed to be selectively operated between a practice mode and a production mode, the air supply unit being arranged to supply the impact mitigation system with air in the practice mode around the landing area. to be provided with an impact attenuating surface,

wherein the air supply unit is arranged not to supply air to the impact attenuation system in the production mode to provide the landing area without an impact attenuation surface.

A method of manufacturing a first inflatable structure (14) for an impact mitigation system, the method comprising: - providing a first fabric (101), - providing a second fabric (102), - contacting a first side (112) of the second cloth with a first side (111) of the first cloth along a first plurality of parallel first connecting lines (103-1, 103-2, 103-3), - connecting the first side of the second cloth with the first side of the first fabric along a first plurality of parallel first connecting lines (103-1, 103-2, 103-3) about a first plurality (104) of parallel first air chambers (104-1, 104-2, 104 -3) extending in the first direction (D1).

The method of claim 23, wherein the first side of the first fabric is joined to the first side of the second fabric along the first plurality of parallel first joining lines using a plurality of lines of adhesive, a plurality of lines of glue, a plurality of glue dots arranged along a line, a plurality of welds, a plurality of seams, a plurality of stitched seams, and/or a plurality of heat seals.

A method of manufacturing an impact attenuation system, the method comprising the method of manufacturing a first inflatable structure for an impact attenuation system according to any one of claims 23 to 24, and wherein the method further comprises: - providing a topsheet (110), - covering at least a portion of the first plurality of first parallel air chambers formed by the first fabric and the second fabric with the top layer, so as to provide the impact attenuation system with an upper outer surface adapted to distribute an impact pressure applied to the upper outer surface of the impact attenuation system over a plurality of parallel first chambers of the first plurality of parallel first air chambers and/or so as to provide the impact attenuation system with a substantially flat top impact surface.

A method of manufacturing an impact mitigation system according to claim 25, the method further comprising: - for covering at least the portion of the first plurality of parallel first air chambers with the top layer: inflating the first plurality of parallel first air chambers to form a first plurality of parallel first tubular airbags arranged side by side in a first plane.

A method of manufacturing an impact mitigation system (2), the method comprising the method of manufacturing a first inflatable structure (14) according to any one of claims 23 to 24, and wherein the method further manufacturing a second inflatable structure (24 ) includes. wherein manufacturing the second inflatable structure comprises: - providing a third fabric (103). and - providing a fourth cloth (104).

- contacting a first side of the third cloth with a first side of the fourth cloth along a second plurality of parallel second connecting lines, - connecting the first side of the third cloth with a first side of the fourth cloth along a second plurality of parallel second connecting lines to form a second plurality of parallel second air chambers extending in a second direction.

- arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers.

28. Method for manufacturing an impact attenuation system according to claim 1

27. wherein arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers comprises: arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers with the second direction perpendicular to the first direction.

The method of manufacturing an impact mitigation system according to claim 27, wherein arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers comprises: arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers with the second direction parallel to the first direction.

The method of manufacturing an impact attenuation system according to claim 27, wherein arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers comprises: arranging the second plurality of parallel second air chambers on top of the first plurality of second parallel air chambers with the second direction at an angle other than 0 degrees and other than 90 degrees to the first direction, e.g. below 30 degrees or 45 degrees.

A method of manufacturing an impact mitigation system according to any one of claims 27 to 30, the method further comprising: - providing a top layer (110), - covering at least a portion of the second plurality of parallel first air chambers formed by said third cloth and the fourth cloth with the top layer, so as to provide the impact attenuation system with an upper outer surface adapted to distribute an impact pressure applied to the upper outer surface of the impact attenuation system over a plurality of parallel second chambers of the second plurality of parallel second air chambers and/or to impact mitigation system so as to provide a substantially flat upper impact surface.

32. Method for manufacturing an impact attenuation system according to claim 1

31. the method further comprising: - before covering at least the portion of the second plurality of parallel second air chambers with the topsheet: inflating the second plurality of parallel first air chambers to form a second plurality of parallel second tubular airbags, arranged side by side in a second plane.