GB2431859A

GB2431859A - A body protecting device comprising an array of energy absorbing cells

Info

Publication number: GB2431859A
Application number: GB0522148A
Authority: GB
Inventors: Peter James Sajic
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-10-31
Filing date: 2005-10-31
Publication date: 2007-05-09
Also published as: ATE523102T1; WO2007052015A3; EP1942759A2; EP1942759B1; GB0522148D0; ES2372867T3; CN101299938B; WO2007052015A2; JP2009513841A; JP5086268B2; US20080307568A1; CN101299938A

Abstract

A body protecting device for wearing by a user comprising: an impact surface; and an array of energy absorbing cells, wherein each of said cells comprises a tube, and wherein the longitudinal axis of the tubes of one or more of said cells is arranged at an oblique angle to the impact surface.

Description

1 Body Protecting Device 3 The present invention relates to body

protecting 4 devices. In particular, but not exclusively, the invention relates to the energy absorbing materials 6 used in devices having a relatively large curvature 7 such as safety helmets, elbow pads, knee pads, 8 shoulder pads and the like.

Safety helmets conventionally comprise a 11 substantially spheroidal outer skin of tough 12 plastics material and an inner skin of resilient 13 material such as a hard foam. The rigid outer skin 14 acts as an impact surface to transmit an impact load more evenly to the inner skin which absorbs the 16 energy imparted by the impact load.

18 The purpose of any body protecting device is firstly 19 to reduce the initial impact load transmitted to the user and secondly to absorb all of the impact energy 21 in a controlled and steady manner. It is often 22 highly desirable that the stiffness or energy 1 absorbing response of the device varies throughout 2 the device. Typically, the liner of a crash helmet 3 can have between two and ten portions of varying 4 density. It is desirable to provide a device, or material for the device, in which the stiffness or 6 energy absorbing response can be easily varied. It 7 is not known to provide a liner which uses different 8 materials or different geometrical arrangements at 9 different locations.

11 It is known that body protecting devices, in 12 particular motorcycle safety helmets, are often 13 subject to impacts more frequently at particular 14 areas or locations of the device. Also, some parts of the body of a user are more prone to injury, or 16 the effects of injury are more severe, than others.

17 It is therefore desirable to provide a device which 18 has the highest level of protection at these 19 respective areas. However, a device which provides this high level of protection at all locations is 21 more difficult or costly to produce.

23 A body protecting device which includes an array of 24 energy absorbing tubes is disclosed in WO 2005/060778. The tubes are arranged such that in 26 use they are axially loaded. The device outperforms 27 conventional devices using a hard foam material to 28 absorb impact energy.

Axially loaded columns have been used for some time 31 to improve the structural crashworthiness of 32 vehicles, roadside furniture and the like. The 1 columns of each of these known systems are typically 2 unconnected and function independently.

4 It is desirable that metal columns exhibit a multiple local buckling and folding failure mode 6 which is effective in absorbing impact energy.

7 Plastic and composite columns have a number of 8 failure modes which are efficient for absorbing 9 impact energy but all of the modes typically involve progressive crushing of one end of the column.

12 The performance and failure mode of plastic and 13 composite columns depends on a complex interaction 14 of a number of different parameters including the material used, the geometry (shape and thickness), 16 fibre alignment in composites, the use of triggers, 17 and the loading conditions. However, a careful 18 selection of these parameters can result in a safety 19 device which outperforms the metal equivalent.

21 Regardless of the material used, arrays of 22 independent columns arranged parallel or coaxial to 23 the load have generally been found to provide 24 efficient energy absorbing performance and improve the stability of the safety device. Columns tend to 26 produce a relatively constant level of energy 27 absorption as the column is progressively buckled or 28 crushed.

It is also known to use one or more cylindrical 31 structural members which are laterally loaded. In 32 other words, the axis of the cylindrical structural 1 member is normal to the loading. Impact energy is 2 absorbed as the circular cross section is 3 progressively crushed flat.

It is known to use composite materials having 6 directional fibres reinforced within a matrix 7 material. The direction of the fibres relative to 8 the loading can be varied to provide the desired 9 loading response. However, since the matrix material is solid, the composite material is 11 relatively dense. Also, the loading response of a 12 composite material having fibres oriented at an 13 angle is typically dominated by the properties of 14 the matrix material. These properties are often an order of magnitude lower than those of the fibre 16 material. Also, although the material may have 17 fibres arranged at an oblique angle to the load, the 18 structure as a whole is still arranged parallel or 19 normal to the loading.

21 According to a first aspect of the present invention 22 there is provided a body protecting device for 23 wearing by a user comprising: 24 an impact surface; an array of energy absorbing cells, wherein 26 each of said cells comprises a tube, and wherein the 27 longitudinal axis of the tubes of one or more of 28 said cells is arranged at an oblique angle to the 29 impact surface.

31 The term "tube" is used to denote a hollow structure 32 having any regular or irregular geometry.

1 Preferably the tube has a cylindrical or conical 2 structure, most preferably a circular cylindrical or 3 circular conical structure.

Preferably the longitudinal axis of the tubes is 6 arranged at an angle of between 50 and 45 to a line 7 normal to the impact surface, most preferably at an 8 angle of between 50 and 30 to a line normal to the 9 impact surface.

11 Preferably the oblique arrangement of tubes is 12 adapted to provide deflecting means for causing 13 lateral deflection of the impact of an impacting 14 object at the impacting surface.

16 Preferably the impact surface is convex.

17 Alternatively, the impact surface is planar or 18 concave.

Preferably the body protecting device has an outer 21 layer providing the impact surface. Preferably the 22 body protecting device has an inner surface and the 23 axis of the one or more tubes extend from the impact 24 surface towards the inner surface. Preferably the body protecting device includes an inner layer 26 providing the inner surface. Preferably the body 27 protecting device includes an intermediate layer 28 providing the array of energy absorbing cells.

Preferably the array is localised at a particular 31 area in the plane of the body protecting device.

32 Preferably a plurality of arrays are provided at 1 discrete locations of the body protecting device.

2 Preferably the intermediate layer comprises a 3 plurality of arrays provided at discrete locations 4 below the impact surface.

6 Preferably one or more of the plurality of arrays 7 include tubes which are orientated at a different 8 oblique angle to the tubes of the other of the 9 plurality of arrays. Preferably the device also includes one or more arrays of tubes in which the 11 axis of one or more tubes is arranged at an angle 12 which is normal to the impact surface.

14 Preferably each of the plurality of arrays comprises an insert provided at a spacing member. Preferably 16 the spacing member is formed from at least a foam 17 material.

19 Preferably the body protecting device comprises a safety helmet. Alternatively, the body protecting 21 device comprises a safety pad or a liner for a 22 garment. The term "body protecting device" is also 23 intended to include a liner for a safety helmet, 24 safety pad or the like.

26 Preferably substantially each tube has a side wall 27 which abuts the side wall of at least another tube.

28 Preferably substantially each tube has a side wall 29 which is connected to the side wall of at least another tube.

1 Preferably substantially each tube has a side wall 2 which is connected to the side wall of at least 3 another tube by an adhesive. Preferably 4 substantially each tube has a side wall which is connected to the side wall of at least another tube 6 substantially along the length of the tube.

8 Alternatively, substantially each tube has a side 9 wall which is welded or fused to the side wall of at least another tube.

12 One or more tubes may be formed from an inner core 13 comprising a first material and an outer core 14 comprising a second material. Preferably each of the first and second material is a polymer.

16 Preferably the second material has a lower melting 17 temperature than the first material.

19 Preferably substantially each tube is near or adjacent to at least three other tubes. Preferably 21 substantially each tube is near or adjacent to six 22 other tubes.

24 Preferably each tube has a diameter of between 2 and 25 mm. Preferably each tube has a diameter of about 26 8 mm.

28 Preferably the thickness of the side wall of each 29 tube is less than 0.5 mm. Preferably the thickness of the side wall of each tube is between 0.1 and 0.3 31 mm.

1 Preferably the length of each tube is between 10 and 2 50mm.

4 Preferably the array of energy absorbing cells is provided as an integral material. Preferably the 6 density of the material is between 60 and 100 kg/rn3, 7 most preferably around 80 kg/rn3.

9 Preferably the integral material comprises polycarbonate, polypropylene, polyethylene, 11 polyetherirnide, polyethersulphone, 12 polyphenylsulphone, polyvinyl chloride, polyethylene 13 terephthalate, ethylene vinyl acetate or 14 acrylonitrile butadiene styrene. Preferably the material comprises Tubus HoneycombsTM.

17 According to a second aspect of the present 18 invention there is provided a body protecting device 19 for wearing by a user comprising: an impact surface; 21 an array of energy absorbing cells, wherein 22 each cell comprises a tube; and 23 deflecting means adapted to cause lateral deflection 24 of the impact of an impacting object at the impacting surface.

27 Preferably the deflecting means is provided by 28 arrangement of the axis of one or more tubes at an 29 oblique angle to the impact surface.

31 Preferably the axis of one or more tubes is arranged 32 at an angle of between 5 and 450 to a line normal 1 to the impact surface, most preferably at an angle 2 of between 5 and 30 to a line normal to the impact 3 surface.

Preferably the array is localised at a particular 6 area in the plane of the device. Preferably a 7 plurality of arrays are provided at different 8 locations of the device. Preferably one or more of 9 the plurality of arrays include tubes which are orientated at a different oblique angle to the tubes 11 of the other of the plurality of arrays. Preferably 12 the liner also includes one or more arrays of tubes 13 in which the axis of one or more tubes is arranged 14 at an angle which is normal to the impact surface.

16 It is to be appreciated that the deflecting means 17 may be adapted to cause lateral deflection of the 18 impact of an impacting object in more than one 19 direction depending on the location where the object impacts the device.

22 Preferably the body protecting device comprises a 23 safety helmet. Alternatively, the body protecting 24 device comprises a safety pad or a liner for a garment. The term "body protecting device" is also 26 intended to include a liner for a safety helmet, 27 safety pad or the like.

29 According to a third aspect of the present invention there is provided a method of absorbing energy 31 imparted by an impact load applied in a first 32 direction comprising: 1 providing an array of energy absorbing cells, 2 wherein each of said cells comprises a tube; 3 orientating the array such that the 4 longitudinal axis of the tubes of one or more of said cells is at an oblique angle to the first 6 direction.

8 According to a fourth aspect of the present 9 invention there is provided a body protecting device for wearing by a user comprising: 11 a spacing member formed from a first material 12 and defining one or more receptacles in the plane of 13 the spacing member; and 14 one or more inserts formed from a second material, the or each insert located at a receptacle 16 of the spacing member.

18 It is to be appreciated that the plane of the 19 spacing member may be flat or arcuate.

21 The or each receptacle may be an aperture, recess or 22 cavity.

24 Preferably the spacing member defines a plurality of receptacles at selected locations in the plane of 26 the spacing member.

28 Preferably the first material comprises a foam.

29 Preferably the first material comprises expanded polystyrene.

1 Preferably the or each insert comprises an array of 2 energy absorbing cells, wherein each cell comprises 3 a tube. Preferably the body protecting device has an 4 impact surface and the axis of one or more tubes is arranged at an oblique angle to the impact surface.

6 Alternatively or in addition, the axis of one or 7 more tubes may be arranged at an angle which is 8 normal to the impact surface.

Preferably the axis of one or more tubes is arranged 11 at an angle of between 5 and 45 to a line normal 12 to the impact surface, most preferably at an angle 13 of between 5 and 3Q0 to a line normal to the impact 14 surface.

16 Preferably the oblique arrangement of tubes is 17 adapted to provide deflecting means for causing 18 lateral deflection of an impacting object.

Preferably the impact surface is convex.

21 Alternatively, the impact surface is planar or 22 concave.

24 Preferably the body protecting device has an inner surface and the axis of the one or more tubes extend 26 from the impact surface towards the inner surface.

28 Preferably the body protecting device comprises a 29 safety helmet. Alternatively, the body protecting device comprises a safety pad or a liner for a 31 garment. The term "body protecting device" is also 1 intended to include a liner for a safety helmet, 2 safety pad or the like.

4 Preferably substantially each tube has a side wall which abuts the side wall of at least another tube.

6 Preferably substantially each tube has a side wall 7 which is connected to the side wall of at least 8 another tube.

Preferably substantially each tube has a side wall 11 which is connected to the side wall of at least 12 another tube by an adhesive. Preferably 13 substantially each tube has a side wall which is 14 connected to the side wall of at least another tube substantially along the length of the tube.

17 Alternatively, substantially each tube has a side 18 wall which is welded or fused to the side wall of at 19 least another tube.

21 Preferably substantially each tube is near or 22 adjacent to at least three other tubes. Preferably 23 substantially each tube is near or adjacent to six 24 other tubes.

26 Preferably each tube has a diameter of between 2 and 27 25 mm. Preferably each tube has a diameter of about 28 8mm.

Preferably the thickness of the side wall of each 31 tube is less than 0.5 mm. Preferably the thickness 1 of the side wall of each tube is between 0.1 and 0.3 2 mm.

4 Preferably the length of each tube is between 10 and 50 mm.

7 Preferably the array of energy absorbing cells is 8 provided as an integral material. Preferably the 9 density of the material is between 60 and 100 kg/rn3, most preferably around 80 kg/rn3.

12 Preferably the second material comprises 13 polycarbonate, polypropylene, polyethylene, 14 polyetherimide, polyethersulphone, polyphenylsuiphone, polyvinyl chloride, polyethylene 16 terephthalate, ethylene vinyl acetate or 17 acrylonitrile butadiene styrene. Preferably the 18 second material comprises Tubus HoneyconthsTM.

Preferably the array defines a first and second 21 discontinuous surface. Preferably a sealing 22 material is provided at one or both of the first and 23 second discontinuous surfaces.

According to a fifth aspect of the present invention 26 there is provided a method of forming a body 27 protecting device for wearing by a user, the method 28 comprising: 29 forming a spacing member from a first material, the spacing member defining one or more receptacles 31 in the plane of the spacing member; 1 forming one or more inserts from a second 2 material; and 3 locating the or each insert at a receptacle of 4 the spacing member.

6 it is to be appreciated that the plane of the 7 spacing member may be flat or arcuate.

9 Preferably the spacing member defines a plurality of receptacles at selected locations in the plane of 11 the spacing member.

13 Preferably the method includes locating the or each 14 insert at the receptacle before or during forming the spacing member.

17 Preferably the method includes encapsulating the or 18 each insert within the spacing member.

Preferably the first material comprises a foam.

21 Preferably the first material comprises expanded 22 polystyrene.

24 Preferably the body protecting device comprises a safety helmet. Alternatively, the body protecting 26 device comprises a safety pad or a liner for a 27 garment. The term "body protecting device" is also 28 intended to include a liner for a safety helmet, 29 safety pad or the like.

1 Preferably the or each insert comprises an array of 2 energy absorbing cells, wherein each cell comprises 3 a tube.

Preferably the array of energy absorbing cells is 6 provided as an integral material. Preferably the 7 density of the material is between 60 and 100 kg/rn3, 8 most preferably around 80 kg/m3.

Preferably the second material comprises 11 polycarbonate, polypropylene, polyethylene, 12 polyetherirrijde, polyethersulphone, 13 polyphenylsulphone, polyvinyl chloride, polyethylene 14 terephthalate, ethylene vinyl acetate or acrylonitrile butadiene styrene. Preferably the 16 second material comprises Tubus HoneycombsTM.

18 Preferably the array defines a first and second 19 discontinuous surface. Preferably the method includes providing a sealing material at one or both 21 of the first and second discontinuous surfaces.

23 An embodiment of the present invention will now be 24 described, by way of example only, with reference to the accompanying drawings, in which: 27 Fig. 1 (a) is a perspective view of a safety helmet 28 in accordance with a first aspect of the present 29 invention; 31 Fig. 1 (b) is a sectional side view of a portion of 32 the safety helmet of Fig. 1 (a); 2 Fig. 2 is a plan view of a tubular array of cells 3 used in the safety helmet of Fig. 1 (a); Fig. 3 is a side view of a tubular array of cells 6 used in the safety helmet of Fig. 1 (a); 8 Fig. 4 is a selection of graphs of test results for 9 an arrangement of cells at 5 to the loading under various test conditions; 12 Fig. 5 is a selection of graphs of test results for 13 an arrangement of cells at 30 to the loading under 14 various test conditions; 16 Fig. 6 is graph of a summary of test results for an 17 arrangement of cells at various angles to the 18 loading and at three impact velocities and for a 19 material at a cold temperature; 21 Fig. 7 is graph of a summary of test results for an 22 arrangement of cells at various angles to the 23 loading and at three impact velocities and for a 24 material at an ambient temperature; 26 Fig. 8 is graph of a summary of test results for an 27 arrangement of cells at various angles to the 28 loading and at three impact velocities and for a 29 material at a hot temperature; 1 Fig. 9 is a cross sectional side view of a portion 2 of a safety helmet in accordance with a fourth 3 aspect of the present invention; Fig. 10 is a plan view of the portion of the safety 6 helmet of Fig. 9; 8 Fig. 11 is a side view of a safety helmet showing 9 testing locations; and 11 Fig. 12 is a front view of the safety helmet of Fig. 12 11.

14 Fig. 1 (a) and (b) shows a first embodiment of a body protecting device in the form of a safety 16 helmet 10. The helmet 10 comprises a first material 17 or core 20 which is sandwiched between a second 18 material or outer layer 30 and a third material or 19 inner layer 40. The outer layer 30 provides an impact surface. Each of the outer 30 and inner 50 21 layer are bonded to the core using an adhesive. In 22 this embodiment, each of the first, second and third 23 materials are continuous throughout the (arcuate) 24 major plane of the helmet 10.

26 The core has a tubular structure which may be a 27 cylindrical arrangement as shown in Fig. 2. The 28 tubes 22 are arranged in a close packed array such 29 that the gap between adjacent tubes is minimised.

31 Fig. 3 (a) shows a first arrangement of tubes 22 32 according to the invention when subject to a load 1 50. The load 50 is normal to the plane of the core 2 20. Each tube 22 has a longitudinal axis 24 which 3 is at an oblique angle 26 to the direction of the 4 load 50. The longitudinal axis 24 of each tube 22 is also at a reciprocal oblique angle 26 to the 6 plane of the core.

8 Fig. 3 (b) shows a second arrangement of tubes 22 9 according to the invention when subject to a load 50 which is applied in a first direction. In this 11 case, each tube 22 has a longitudinal axis 24 which 12 is normal to the plane of the core 20. However, the 13 core 20 is arranged such that the plane of the core 14 20 is at an oblique angle 26 to the first direction.

This arrangement represents another method of 16 absorbing the energy imparted by an impact load.

18 Although Fig. 3 (a) and (b) shows a planar 19 arrangement of tubes 22, it is to be appreciated that an impact loading to a spherical structure such 21 as a crash helmet or safety pad tends to be in a 22 direction normal to a tangent of the sphere.

23 Therefore, the same oblique arrangement would be 24 present when the tubes are curved to form the core of a crash helmet or safety pad.

27 Each tube has a diameter of 8 mm, a thickness of 28 between 0.1 and 0.3 mm, and a length of around 35 29 mm. This results in a slenderness ratio (the ratio of the length to the diameter) of around 4, and an 31 aspect ratio (the ratio of the diameter to the 32 thickness)of between 25 and 80.

2 The use of these geometric values, particularly the 3 low thickness used, results in a stable failure mode 4 of progressive buckling being achieved, even though the tubes are at an angle to the loading.

6 Instability, which could lead to a global buckling 7 failure mode, is avoided since the tubes are 8 connected to, and supported by, adjacent tubes.

9 Being connected to six other tubes which are circumferentially spaced around the tube provides 11 such support in any direction normal to the axis of 12 the tube.

14 The tubes may be bonded together using an adhesive.

Another suitable method is to form the tubes from an 16 inner core of a first material and an outer core of 17 a second material, the cores being co-extruded. The 18 second material can be selected to have a lower 19 melting temperature than the first material.

Typically, a difference of between 15 and 20 21 Celsius can be used. During forming, the tubes can 22 be heated to a temperature between the melting 23 temperature of the first and second material. This 24 causes the side walls of the tubes to become welded or fused together. This method allows easier 26 forming of shapes and gives better consistency 27 during forming.

29 It is to be appreciated that the tubes need not be connected to provide support to each other, or even 31 be abutting, as long as the tubes are in close 1 proximity such that they come into contact following 2 a small amount of deformation.

4 It has been found that the present invention can outperform arrangements in which the tubes are 6 parallel or normal to the loading. It is believed 7 that the main reason for this is that the angled 8 arrangement of tubes produces a reaction load which 9 has both a parallel and a normal component relative to the loading. The normal component causes lateral 11 deflection of the impacting object relative to the 12 body protecting device during deformation of the 13 tubes. The overall angled displacement of the head 14 form results in a longer total time period for the impact event. Also, deflection of the impacting 16 object reduces the magnitude of the loading in the 17 parallel direction. Thus, the total impact energy 18 is absorbed at a lower magnitude over a longer time 19 period.

21 Another reason for the superior performance of the 22 invention may be the contribution of bending of the 23 tubes without buckling. There is therefore another 24 mode of absorbing energy in addition to the mode of progressive buckling exhibited by both a 26 conventional arrangement and the invention.

28 Figs. 4 and 5 are representative samples of test 29 results for a material according to the invention which is impacted at two different impact 31 velocities: 4 and 6.7 m/s. Also, three different 32 temperatures of the material were used: a relatively 1 cold temperature of -30 C, an ambient temperature of 2 20 C, and a relatively hot temperature of 110 C. In 3 Fig. 4, a tube angle of 5 to the loading was used.

4 In Fig. 5, a tube angle of 30 to the loading was used.

7 The test results of Figs. 4 and 5 measure the 8 acceleration of the impacting object during the 9 impact event. The impact force is directly proportional to the acceleration of the impacting 11 object since the impact force is simply the product 12 of the mass of the impacting object and its 13 acceleration. In each of the tests, the force 14 increases and then decreases in a steady manner.

Therefore, the impact energy is absorbed in a 16 controlled and steady manner.

18 Various test results are summarised in Figs. 6 to 8.

19 It is clear that the impact force that would be transmitted to a wearer of the associated body 21 protecting device tends to decrease as the tube 22 angle is increased. This is particularly the case 23 at ambient or cold temperatures which are more 24 likely to be the environmental conditions during use.

27 High speed video playback of an impact event shows 28 the impacting object being deflected laterally as 29 the tubes are deformed.

31 In a body protecting device, it is possible to vary 32 the angle of the tubes relative to the impact 1 surface such that the stiffness or energy absorbing 2 response of the material varies throughout the 3 device. Using an integral core material allows 4 moulding of a material which has an array of tubes at any angle up to 45 . This eliminates the need to 6 cut the material at a particular angle which would 7 result in substantial wastage.

9 Fig. 9 shows a body protecting device for wearing by a user, again a safety helmet 100, according to a 11 fourth aspect of the present invention.

13 The helmet 100 comprises a spacing member 110 formed 14 from a first material, which is an expanded polystyrene foam. The spacing member 110 defines a 16 number of receptacles or cavities 112 at selected 17 locations in the (arcuate) major plane of the 18 spacing member 110.

An insert 120, 122, 124 formed from a second 21 material, is encapsulated within each cavity.

22 Alternatively, apertures or recesses can be formed 23 in the spacing member 110. Methods of providing 24 such formations in foam materials are well known.

26 The inserts 120, 122, 124 may be positioned during 27 forming of the spacing member 110 or inserted 28 afterwards, such as by forming pockets in the 29 spacing member 110. 31 Each insert 120, 122, 124 comprises an array of 32 energy absorbing

tubes as described for the first 1 embodiment of the invention. For some of the 2 inserts 122, 124, the axis of the tubes are arranged 3 at an oblique angle to an impact surface 102 of the 4 helmet 100. Also, the specific oblique angle may differ for these inserts 122, 124. For the 6 remainder of the inserts 120, the axis of the tubes 7 are arranged at an angle which is normal to the 8 impact surface 102.

Fig. 10 is a plan view of the helmet 100 with the 11 arrow 140 pointing outwards from the front of the 12 helmet 100.

14 At the front and rear of the helmet 100, which have a smaller radius section, the helmet 100 is more 16 stiff and using an insert 120 with an angle of 90 17 to the impact surface 102 is beneficial. At the two 18 side portions of the helmet 100, which have a higher 19 radius section, the helmet 100 is more flexible and using an insert 124 with an angle of 30 , and even 21 up to 45 , to the impact surface 102 is beneficial.

22 The top of the helmet 100 has a section of 23 intermediate radius and using an insert 120 with an 24 angle of 15 to the impact surface 102 is beneficial.

27 Helmet stiffness at any particular location can vary 28 depending on the stiffness or thickness of the 29 materials used, as well as the radius of curvature.

The tube angle can be varied to meet these 31 requirements and optimise the overall energy 32 absorbing performance of the helmet 100.

2 As previously described, the arrays of the inserts 3 are provided as an integral material. The inserts 4 may be of any geometric shape. Typical dimensions of the inserts are 75 mm2 for a square insert and a 6 diameter of 90 mm for a circular insert.

8 Each array defines a first 130 and second 132 9 discontinuous surface. A sealing material (not shown) is provided at both of these discontinuous 11 surfaces. This prevents the foam material from 12 entering the open ends of the tubes.

14 The inserts 120, 122 provide a high level of protection from impact loads. The arrays are 16 located at particular predetermined areas where 17 impacts occur more frequently or which are adjacent 18 to parts of the body of a user which are more prone 19 to injury, or the effects of injury are more severe.

Moreover, the orientation of the tubes can be 21 arranged to provide the optimum protection for a 22 particular location.

24 Helmets tend to be tested at these vulnerable locations to ensure that they meet acceptable levels 26 of safety. Two safety standards are the European 27 standard EC R22-05 and the US standard SNELL 2005, 28 both of which specify similar testing locations.

29 Figs. 11 and 12 show the testing locations 151 -155 for EC R22-05.

1 The distance to the testing locations 151 -155 is 2 taken from a reference point 160 located at the top 3 and centre of the visor aperture 162. These 4 distances are given in the standard. Inserts can be provided at each of these locations 151 -155.

7 In other areas of the helmet 100, an acceptable 8 level of protection is still provided by the foam 9 spacing member 110. Indeed, the level of protection is at least equal to that of conventional helmets 11 which use only a foam core.

13 Various modifications and improvements can be made 14 without departing from the scope of the present invention.

Claims

1 CLAIMS 3 1. A body protecting device for wearing by a user 4

comprising: an impact surface; 6 an array of energy absorbing cells, wherein 7 each of said cells comprises a tube, and wherein the 8 longitudinal axis of the tubes of one or more of 9 said cells is arranged at an oblique angle to the impact surface.

12
2. A body protecting device as claimed in Claim 1, 13 wherein the axis of each tube is arranged at an 14 angle of between 5 and 45 to a line normal to the impact surface.

17
3. A body protecting device as claimed in Claim 1, 18 wherein the axis of each tube is arranged at an 19 angle of between 15 and 30 to a line normal to the impact surface.

22
4. A body protecting device as claimed in any 23 preceding claim, wherein the oblique arrangement of 24 tubes is adapted to provide deflecting means for causing lateral deflection of the impact of an 26 impacting object at the impacting surface.

28
5. A body protecting device as claimed in any 29 preceding claim, wherein the impact surface is convex.

1
6. A body protecting device as claimed in any 2 preceding claim including an inner surface, and 3 wherein the axis of the one or more tubes extends 4 from the impact surface towards the inner surface.

6
7. A body protecting device as claimed in any 7 preceding claim, wherein the array is localised at a 8 particular area in the plane of the body protecting 9 device.

11
8. A body protecting device as claimed in any 12 preceding claim, wherein a plurality of arrays are 13 provided at different locations of the body 14 protecting device.

16
9. A body protecting device as claimed in Claim 8, 17 wherein one or more of the plurality of arrays 18 include tubes which are orientated at a different 19 oblique angle to the tubes of the other of the plurality of arrays.

22
10. A body protecting device as claimed in Claim 8 23 or 9, wherein the device also includes one or more 24 arrays of tubes in which the axis of one or more tubes is arranged at an angle which is normal to the 26 impact surface.

28
11. A body protecting device as claimed in any of 29 Claims 8 to 10, wherein each of the plurality of arrays comprises an insert provided at a spacing 31 member.

1
12. A body protecting device as claimed in Claim 2 11, wherein the spacing member is formed from at 3 least a foam material.

13. A body protecting device as claimed in any 6 preceding claim, wherein the body protecting device 7 comprises a safety helmet.

9 14. A body protecting device as claimed in any preceding claim, wherein substantially each tube has 11 a side wall which abuts the side wall of at least 12 another tube.

14 15. A body protecting device as claimed in any preceding claim, wherein substantially each tube has 16 a side wall which is connected to the side wall of 17 at least another tube.

19 16. A body protecting device as claimed in Claim 15, wherein substantially each tube has a side wall 21 which is connected to the side wall of at least 22 another tube by an adhesive.

24 17. A body protecting device as claimed in Claim 15 or 16, wherein substantially each tube has a side 26 wall which is connected to the side wall of at least 27 another tube substantially along the length of the 28 tube.

18. A body protecting device as claimed in any 31 preceding claim, wherein one or more tubes may be 32 formed from an inner core comprising a first 1 material and an outer core comprising a second 2 material.

4 19. A body protecting device as claimed in Claim 18, wherein each of the first and second material is 6 a polymer, and wherein the second material has a 7 lower melting temperature than the first material.

9 20. A body protecting device as claimed in any preceding claim, wherein substantially each tube is 11 near or adjacent to at least three other tubes.

13 21. A body protecting device as claimed in any 14 preceding claim, wherein substantially each tube is near or adjacent to six other tubes.

17 22. A body protecting device as claimed in any 18 preceding claim, wherein each tube has a diameter of 19 between 2 and 25 mm.

21 23. A body protecting device as claimed in any 22 preceding claim, wherein the thickness of the side 23 wall of each tube is less than 0.5 mm.

24. A body protecting device as claimed in any 26 preceding claim, wherein the length of each tube is 27 between 10 and 50 mm.

29 25. A body protecting device as claimed in any preceding claim, wherein the array of energy 31 absorbing cells is provided as an integral material.

1 26. A body protecting device as claimed in any 2 preceding claim, wherein the density of the material 3 is between 60 and 100 kg/rn3.

27. A body protecting device as claimed in Claim 6 25, wherein the integral material comprises one of 7 polycarbonate, polypropylene, polyethylene, 8 polyetherimide, polyethersulphone, 9 polyphenylsulphone, polyvinyl chloride, polyethylene terephthalate, ethylene vinyl acetate or 11 acrylonitrile butadiene styrene.

13 28. A body protecting device for wearing by a user 14 comprising: an impact surface; 16 an array of energy absorbing cells, wherein 17 each cell comprises a tube; and 18 deflecting means adapted to cause lateral 19 deflection of the impact of an impacting object at the impacting surface.

22 29. A body protecting device as claimed in Claim 23 28, wherein the deflecting means is provided by 24 arrangement of the axis of each tube at an oblique angle to the impact surface.

27 30. A body protecting device as claimed in Claim 28 29, wherein the axis of each tube is arranged at an 29 angle of between 5 and 450 to a line normal to the impact surface.

1 31. A body protecting device as claimed in any of 2 Claims 28 to 30, wherein the array is localised at a 3 particular area in the plane of the device.

32. A body protecting device as claimed in any of 6 Claims 28 to 30, wherein a plurality of arrays are 7 provided at different locations of the device.

9 33. A body protecting device as claimed in Claim 32, wherein one or more of the plurality of arrays 11 include tubes which are orientated at a different 12 oblique angle to the tubes of the other of the 13 plurality of arrays.

34. A method of absorbing energy imparted by an 16 impact load applied in a first direction comprising: 17 providing an array of energy absorbing cells, 18 wherein each of said cells comprises a tube; 19 orientating the array such that the longitudinal axis of the tubes of one or more of 21 said cells is at an oblique angle to the first 22 direction.

24 35. A body protecting device for wearing by a user comprising: 26 a spacing member formed from at least a first 27 material and defining one or more receptacles in the 28 plane of the spacing member; and 29 one or more inserts formed from a second material, the or each insert located at a receptacle 31 of the spacing member.

1 36. A body protecting device as claimed in Claim 2 35, wherein the or each receptacle is an aperture, 3 recess or cavity.

37. A body protecting device as claimed in Claim 35 6 or 36, wherein the spacing member defines a 7 plurality of receptacles at selected locations in 8 the plane of the spacing member.

38. A body protecting device as claimed in any of 11 Claims 35 to 37, wherein the first material 12 comprises a foam.

14 39. A body protecting device as claimed in any of Claims 35 to 38, wherein the or each insert 16 comprises an array of energy absorbing cells, 17 wherein each cell comprises a tube.

19 40. A body protecting device as claimed in Claim 39, including an impact surface, and wherein the 21 axis of one or more tubes is arranged at an oblique 22 angle to the impact surface.

24 41. A body protecting device as claimed in Claim 40, wherein the axis of one or more tubes is 26 arranged at an angle of between 5 and 45 to a line 27 normal to the impact surface.

29 42. A body protecting device as claimed in Claim 40 or 41, wherein the oblique arrangement of tubes is 31 adapted to provide deflecting means for causing 32 lateral deflection of an impacting object.

2 43. A body protecting device as claimed in any of 3 Claims 35 to 42, including an inner surface, and 4 wherein the axis of the one or more tubes extend from the impact surface towards the inner surface.

7 44. A body protecting device as claimed in any of 8 Claims 35 to 43, wherein the body protecting device 9 comprises a safety helmet.

11 45. A body protecting device as claimed in any of 12 Claims 39 to 43, wherein substantially each tube has 13 a side wall which abuts the side wall of at least 14 another tube.

16 46. A body protecting device as claimed in Claim 17 45, wherein substantially each tube has a side wall 18 which is connected to the side wall of at least 19 another tube.

21 47. A body protecting device as claimed in Claim 22 46, wherein substantially each tube has a side wall 23 which is connected to the side wall of at least 24 another tube substantially along the length of the tube.

27 48. A body protecting device as claimed in any of 28 Claims 39 to 43 or any of Claims 45 to 47, wherein 29 the array of energy absorbing cells is provided as an integral material.

1 49. A body protecting device as claimed in any of 2 Claims 39 to 43 or any of Claims 45 to 48, wherein 3 the array defines a first and second discontinuous 4 surface, and wherein a sealing material is provided at one or both of the first and second discontinuous 6 surfaces.

8 50. A method of forming a body protecting device 9 for wearing by a user, the method comprising: forming a spacing member from a first material, 11 the spacing member defining one or more receptacles 12 in the plane of the spacing member; 13 forming one or more inserts from a second 14 material; and locating the or each insert at a receptacle of 16 the spacing member.

18 51. A method as claimed in Claim 50, wherein the 19 spacing member defines a plurality of receptacles at selected locations in the plane of the spacing 21 member.

23 52. A method as claimed in Claim 50 or 51, 24 including locating the or each insert at the receptacle before or during forming the spacing 26 member.

28 53. A method as claimed in any of Claims 50 to 52, 29 including encapsulating the or each insert within the spacing member.

1 54. A method as claimed in any of Claims 50 to 53, 2 wherein the first material comprises a foam.

4 55. A method as claimed in any of Claims 50 to 54, wherein the or each insert comprises an array of 6 energy absorbing cells, and wherein each cell 7 comprises a tube.

9 56. A method as claimed in Claim 55, wherein the array defines a first and second discontinuous 11 surface, and the method includes providing a sealing 12 material at one or both of the first and second 13 discontinuous surfaces.