A sliding part for protective apparel

Abstract

A sliding part for protective apparel, the sliding part being configured to provide sliding between an inner part of the protective apparel and an outer part of the protective apparel in response to an impact to the protective apparel, the sliding part comprising: an inner layer; and an outer layer; wherein the inner layer and the outer layer are configured to slide relative to each other at a low friction sliding interface in response to an impact to the protective apparel, when the sliding part forms part of the protective apparel; wherein the inner layer and the outer layer are bonded at one or more discrete bonding locations and the bonding is configured to break when a shearing force between the inner layer and the outer layer exceeds a threshold, such that the sliding is permitted at or above the threshold force, but restricted at the bonding locations, by the bonding, below the threshold force.

Description

[0001] A SLIDING PART FOR PROTECTIVE APPAREL

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a sliding part for protective apparel, such as a helmet.

[0004] BACKGROUND ART

[0005] Impact protection apparatuses generally aim to reduce the energy transferred to an object, such as a person to be protected, by an impact. This may be achieved by energy absorbing means, energy redirecting means, or a combination thereof. Energy absorbing means may include energy absorbing materials, such as a foam material, or structures configured to deform elastically and / or plastically in response to an impact. Energy redirecting means may include structures configured to slide, shear or otherwise move in response to an impact.

[0006] Impact protection apparatuses include protective apparel for protecting a wearer of the apparel. Protective apparel comprising energy absorbing means and / or energy redirecting means is known. For example, such means are implemented extensively in protective headgear, such as helmets.

[0007] Examples of helmets comprising energy absorbing means and energy redirecting means include WO 2001 / 045526 and WO 2011 / 139224 (the entirety of which are herein incorporated by reference). Specifically, these helmets include at least one layer formed from an energy absorbing material and at least one layer that can move relative to the head of the wearer of the helmet under an impact.

[0008] Implementing moving parts in protective apparel has challenges. For example, ensuring that friction between moving parts under an impact can be overcome to allow enough relative movement between parts can be challenging. Ensuring that the protective apparel can be manufactured and assembled relatively easily can be challenging.

[0009] It is the aim of the present invention to provide protective apparel that at least partially addresses some of the problems discussed above. STATEMENTS OF THE INVENTION

[0010] According to a first aspect of the disclosure there is provided a sliding part for protective apparel, the sliding part being configured to provide sliding between an inner part of the protective apparel and an outer part of the protective apparel in response to an impact to the protective apparel, the sliding part comprising: an inner layer; and an outer layer; wherein the inner layer and the outer layer are configured to slide relative to each other at a low friction sliding interface in response to an impact to the protective apparel, when the sliding part forms part of the protective apparel; wherein the inner layer and the outer layer are bonded at one or more discrete bonding locations and the bonding is configured to break when a shearing force between the inner layer and the outer layer exceeds a threshold, such that the sliding is permitted at or above the threshold force, but restricted at the bonding locations by the bonding, below the threshold force.

[0011] Optionally, the threshold force exceeds typical forces experienced during normal use of the protective apparel. Optionally, the threshold force is lower than a typical impact force to the protective apparel.

[0012] Optionally, the inner layer and outer layer are in contact with each other at the bonding locations.

[0013] Optionally, the inner layer and outer layer are compressed together at the bonding locations.

[0014] Optionally, the inner layer and / or the outer layer respectively comprise a central portion and an edge portion, the edge portion being arranged at a perimeter of the inner layer and / or the outer layer respectively and surrounding the central portion, and the one or more bonding locations are arranged in the central portion of the inner layer and / or the outer layer respectively.

[0015] Optionally, the one or more bonding locations are arranged exclusively in the central portion of the inner layer and / or the outer layer respectively. Optionally, the one or more bonding locations comprise one or more bonding points having two orthogonal dimensions in a plane of the inner and outer layers that are substantially the same size. Optionally, the bonding points are substantially circular or polygonal in shape.

[0016] Optionally, the bonding comprises a weld between the inner and outer layers.

[0017] Optionally, the inner layer comprises a low friction material.

[0018] Optionally, the inner layer comprises a polymer, such as TPU or PC.

[0019] Optionally, the outer layer is formed from a fabric, such as brushed nylon.

[0020] Optionally, the sliding part further comprises a padding layer on an inner side of the inner layer, such that the inner layer forms an intermediate layer between the padding layer and the outer layer.

[0021] Optionally, the sliding part further comprises a covering layer on an inner side of the padding layer.

[0022] Optionally, the sliding part is a comfort liner. Optionally, the comfort liner is formed by bonding the outer layer, inner layer, padding layer and covering layer together at an edge portion of the comfort liner, the edge portion being arranged at a perimeter of the comfort liner respectively. Optionally, the comfort liner is formed by additionally selectively bonding the padding layer and the covering layer at a central portion of the comfort liner surrounded by the edge portion, wherein the boding locations are provided at locations where the padding layer and the covering layer are selectively bonded.

[0023] According to a second aspect of the disclosure, there is provided a method of forming the sliding part of the first aspect, comprising: providing the inner layer and the outer layer; bonding the inner layer and outer layer at the one or more bonding locations.

[0024] Optionally, the inner layer and / or the outer layer respectively comprise a central portion and an edge portion, the edge portion being arranged at a perimeter of the inner layer and / or the outer layer respectively and surrounding the central portion, and the one or more bonding locations are arranged in the central portion of the inner layer and / or the outer layer respectively; the method further comprising additionally bonding the inner layer and outer layer at the edge portion. Optionally, the bonding at the bonding locations and the edge portion are performed in the same bonding step.

[0025] Optionally, the sliding part is a comfort liner and further comprises a padding layer on an inner side of the inner layer, such that the inner layer forms an intermediate layer between the padding layer and the outer layer, and a covering layer on an inner side of the padding layer; the comfort liner is formed by bonding the outer layer, inner layer, padding layer and covering layer together at the edge portion of the comfort liner, and by selectively bonding the padding layer and the covering layer at the central portion of the comfort liner, wherein the boding locations are provided at locations where the padding layer and the covering layer are selectively bonded. Optionally, the method comprises a fist bonding step in which the padding layer and the covering layer are selectively bonded together and a second bonding step in which the outer layer, inner layer, padding layer and covering layer are bonded together at the edge portion and the one or more bonding locations.

[0026] Optionally, the bonding process comprises welding. Optionally, the welding comprises high frequency welding.

[0027] According to a third aspect of the disclosure there is provided an item of protective apparel comprising the sliding part of the first aspect. Optionally, the item of protective apparel is a helmet. Optionally, the item of protective apparel further comprises an energy absorbing layer and / or a hard outer layer.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention is described in detail below, with reference to the accompanying figures, in which:

[0030] Fig. 1 schematically shows a cross-section through a first example helmet;

[0031] Fig. 2 schematically shows a cross-section through a second example helmet;

[0032] Fig. 3 schematically shows a cross-section through a third example helmet; Fig. 4 schematically shows a cross-section through a fourth example helmet; Fig. 5 schematically shows a cross-section through a fifth example helmet;

[0033] Fig. 6 schematically shows a cross-section through a sixth example helmet;

[0034] Fig. 7 schematically shows a cross-section through a seventh example helmet;

[0035] Fig. 8 shows an eighth example helmet;

[0036] Fig. 9 shows a first example of body armour;

[0037] Fig. 10 shows a second example of body armour;

[0038] Fig. 11 schematically shows a cross-section through a ninth example helmet;

[0039] Fig. 12 schematically depicts, in a cross-section, another arrangement of a helmet;

[0040] Fig. 13 depicts the inside of an example of a helmet according to the arrangement depicted in Fig.12;

[0041] Fig. 14 schematically shows layers forming a sliding part;

[0042] Fig. 15 schematically shows layers forming a sliding part;

[0043] Fig. 16 shows an example sliding part that is a comfort liner;

[0044] Fig. 17 shows an example sliding part that is a comfort liner;

[0045] Fig. 18 shows an example helmet in which sliding part that is a comfort liner.

[0046] DETAILED DESCRIPTION

[0047] Unless otherwise state, it should be noted that the Figures are schematic, the proportions of the thicknesses of the various layers, and / or of any gaps between layers, depicted in the Figures have been exaggerated for the sake of clarity and can of course be adapted according to need and requirements.

[0048] Although the examples described below relate to helmets, it should be understood that the invention applies generally to protective apparatuses, including other types of headgear and other protective apparel.

[0049] Protective apparatuses can be understood to have parts corresponding to the parts of the helmets described below. For example, protective apparatuses may have a layered structure corresponding to the layered structure of the described helmets.

[0050] Terms that are specific to a helmet, such as “radial direction” can be understood to have equivalents in the context of other protective equipment, such as “thickness direction”. A “wearer” is to generally understood as corresponding to an object that is to be protected by the protective apparatus, and “head” as a specific part of the object, e.g. a different body part, with which the apparatus is in contact.

[0051] General features of the example helmets are described below with reference to Figs. 1 to 7.

[0052] Figs. 1 to 7 show example helmets 1 comprising an energy absorbing layer 3. The purpose of the energy absorbing layer 3 is to absorb and dissipate energy from an impact in order to reduce the energy transmitted to the wearer of the helmet. Within the helmet 1, the energy absorbing layer may be the primary energy absorbing element. Although other elements of the helmet 1 may absorb that energy to a more limited extent, this is not their primary purpose.

[0053] The energy absorbing layer 3 may absorb energy from a radial component of an impact more efficiently than a tangential component of an impact. The term “radial” generally refers to a direction substantially toward the centre of the wearers head, e.g. substantially perpendicular to an outer surface of the helmet 1. The term “tangential” may refer to a direction substantially perpendicular to the radial direction, in a plane comprising the radial direction and the impact direction.

[0054] The energy absorbing layer may be formed from an energy absorbing material, such as a foam material. Preferable such materials include expanded polystyrene (EPS), expanded polypropylene (EPP), expanded polyurethane (EPU), vinyl nitrile foam; or strain rate sensitive foams such as those marketed under the brand-names Poron™ and D3O™.

[0055] Alternatively, or additionally, the energy absorbing layer may have a structure that provides energy absorbing characteristics. For example, the energy absorbing layer may comprise deformable elements, such as cells or finger-like projections, that deform upon impact to absorb and dissipate the energy of an impact.

[0056] As illustrated in Fig. 6, the energy absorbing layer 3 of the helmet 1 is divided into outer and inner parts 3A and 3B.

[0057] As illustrated in Fig 11, the energy absorbing layer 3 may be divided into multiple parts arranged adjacent each other in the circumferential direction of the helmet. Figure 11 shows such a helmet 1 of the type shown in Fig. 6, with the inner parts 3B being formed in front and back parts 3C and 3D.

[0058] The energy absorbing layer is not limited to one specific arrangement or material. The energy absorbing layer 3 may be provided by multiple layers having different arrangements, i.e. formed from different materials or having different structures. The energy absorbing layer 3 may be a relatively thick layer. For example, it may be thickest layer of the helmet 1.

[0059] Figs. 1 to 7 show example helmets 1 comprising an outer layer 2. The purpose of the outer layer 2 may be to provide rigidity to the helmet. This may help spread the impact energy over a larger area of the helmet 1. The outer layer 2 may also provide protection against objects that might pierce the helmet 1. Accordingly, the outer layer may be a relatively strong and / or rigid layer, e.g. compared to an energy absorbing layer 3. The outer layer 2 may be a relatively thin layer, e.g. compared to an energy absorbing layer 3. The outer layer 2 may be an outer shell.

[0060] The outer layer 2 may be formed from a relatively strong and / or rigid material. Preferable such materials include a polymer material such as polycarbonate (PC), polyvinylchloride (PVC) or acrylonitrile butadiene styrene (ABS) for example. Advantageously, the polymer material may be fibre-reinforced, using materials such as glass-fibre, Aramid, Twaron, carbon-fibre and / or Kevlar.

[0061] As shown in Fig. 7, one or more outer plates 7 may be mounted to the outer layer 2 of the helmet 1. The outer plates 7 may be formed from a relatively strong and / or rigid material, for example from the same types of materials as from which the outer layer 2 may be formed. The selection of material used to form the outer plates 7 may be the same as, or different from, the material used to form the outer layer 2.

[0062] In some example helmets, the outer layer 2 and / or the energy absorbing layer 3 may be adjustable in size in order to provide a customised fit. For example, the outer layer 2 may be provided in separate front and back parts. The relative position of the front and back parts may be adjusted to change the size of the outer layer 2. In order to avoid gaps in the outer layer 2, the front and back parts may overlap. The energy absorbing layer 3 may also be provided in separate front and back parts. These may be arranged such that the relative position of the front and back parts may be adjusted to change the size of the energy absorbing layer 3. In order to avoid gaps in the energy absorbing layer 3, the front and back parts may overlap.

[0063] Figs. 1 to 4 shows example helmets 1 comprising an interface layer 4. Although not shown in Figs. 5 to 7, these example helmets may also comprise an interface layer 4. The purpose of interface layer 4 may be to provide an interface between the helmet and the wearer. In some arrangements, this may improve the comfort of the wearer. The interface layer 4 may be provided to mount the helmet on the head of a wearer. The interface layer 4 may be provided as a single part or in multiple sections.

[0064] The interface layer 4 may be configured to at least partially conform to the head of the wearer. For example, the interface layer 4 may be elasticated and / or may comprise an adjustment mechanism for adjusting the size of the interface layer 4. In an arrangement, the interface layer may engage with the top of a wearer’s head. Alternatively, or additionally, the interface layer 4 may comprise an adjustable band configured to encircle the wearer’s head.

[0065] The interface layer 4 may comprise comfort padding 4A. Multiple sections of comfort padding 4A may be provided. The comfort padding 4A may be provided on a substrate 4B for mounting the comfort padding to the rest of the helmet 1.

[0066] The purpose of the comfort padding 4 A is to improve comfort of wearing the helmet and / or to provide a better fit. The comfort padding may be formed from a relatively soft material, e.g. compared to the energy absorbing layer 3 and / or the outer layer 2. The comfort padding 4 A may be formed from a foam material. However, the foam material may be of lower density and / or thinner than foam materials used for the energy absorbing layer 3. Accordingly, the comfort padding 4A will not absorb a meaningful amount of energy during an impact, i.e. for the purposes of reducing the harm to the wearer of the helmet. Comfort padding is well recognised in the art as being distinct from energy absorbing layers, even if they may be constructed from somewhat similar materials.

[0067] The interface layer 4, and / or comfort padding 4A that may be part of it, may be removable. This may enable the interface layer 4 and / or comfort padding 4A to be cleaned and / or may enable the provision of an interface layer 4 and / or comfort padding 4 A that is configured to fit a specific wearer.

[0068] Straps, e.g. chin straps, may be provided to secure the helmet 1 to the head of the wearer.

[0069] The helmets of Figs. 1 to 4 are configured such that the interface layer 4 is able to move, for example slide, in a tangential direction relative to the energy absorbing layer 3 in response to an impact. As shown in Figs. 1 to 4, the helmet 1 may also comprise connectors 5 between the energy absorbing layer 3 and the interface layer 4 that allow relative movement between the energy absorbing layer 3 and the interface layer 4, while connecting the elements of the helmet together.

[0070] The helmet of Fig. 5 is configured such that the outer layer 2 is able to move, for example slide, in a tangential direction relative to the energy absorbing layer 3 in response to an impact. As shown in Fig 5, the helmet 1 may also comprise connectors 5 between the energy absorbing layer 3 and the outer layer 2 that allow relative movement between the energy absorbing layer 3 and the outer layer 2, while connecting the elements of the helmet together.

[0071] The helmet of Fig. 6 is configured such that the outer part 3 A of the energy absorbing layer 3 is able to move, for example slide, in a tangential direction relative to the inner part 3B of the energy absorbing layer 3 in response to an impact. As shown in Fig 6, the helmet 1 may also comprise connectors 5 between the outer part 3A of the energy absorbing layer 3 and the inner part 3B of the energy absorbing layer 3, that allow relative movement between the outer part 3 A of the energy absorbing layer 3 and the inner part 3B of the energy absorbing layer 3, while connecting the elements of the helmet together.

[0072] In examples, such as that of Fig. 11, in which an energy absorbing layer is split into multiple parts 3C and 3D arranged adjacent each other in the circumferential direction of the helmet, these parts may be configured to move relative to each other, as well as other parts of the helmet.

[0073] The helmet 1 of Fig. 7 is configured such that the outer plates 7 are able to move, for example slide, in a tangential direction relative to the outer layer 2 in response to an impact. As shown in Fig 7, the helmet 1 may also comprise connectors 5 between the outer plates 7 and the outer layer 2 that allow relative movement between the outer plates 7 and the outer layer 2, while connecting the elements of the helmet together.

[0074] The purpose of helmet layers that move or slide relative to each other may be to redirect energy of an impact that would otherwise be transferred to the head the wearer. This may improve the protection afforded to the wearer against a tangential component of the impact energy. A tangential component of the impact energy would normally result in rotational acceleration of the head of the wearer. It is well known that such rotation can cause brain injury. It has been shown that helmets with layers that move relative to each other can reduce the rotational acceleration of the head of the wearer. A typical reduction may be roughly 25% but reductions as high as 90% may be possible in some instances.

[0075] Preferably, relative movement between helmet layers results in a total shift amount of at least 0.5cm between an outermost helmet layer and an inner most helmet layer, more preferably at least 1cm, more preferably still at least 1.5cm. Preferably the relative movement can occur in any direction, e.g. in a circumferential direction around the helmet, left to right, front to back and any direction in between.

[0076] Relative movement can be considered to occur substantially in a plane over the relevant ranges, even though movement between layers may be rotational rather than linear. Accordingly, reference may be made below to movement in a plane.

[0077] Regardless of how helmet layers are configured to move relative to each other, it is preferable that the relative movement, such as sliding, is able to occur under forces typical of an impact for which the helmet is designed (for example an impact that is expected to be survivable for the wearer). Such forces are significantly higher than forces that a helmet may be subject to during normal use. Impact forces tend to compress layers of the helmet together, increasing the reaction force between components and thus increasing frictional forces. Where helmets are configured to have layers sliding relative to each other the interface between them may need to be configured to enable sliding even under the effect of the high reaction forces experienced between them under an impact. As shown in Figs. 1 to 7, a sliding interface may be provided between the layers of the helmet 1 that are configured to slide relative to each other. At the sliding interface, surfaces slide against each other to enable relative sliding between the layers of the helmet 1. The sliding interface may be a low friction interface. Accordingly, friction reducing means may be provided at the sliding interface. Example sliding interfaces are described further below, in relation to each of the example helmets 1 shown in Figs. 1 to 7.

[0078] The friction reducing means may be a low friction material or lubricating material. These may be provided as a continuous layer, or multiple discrete patches, or portions of material, for example. Possible low friction materials for the friction reducing means include waxy polymers such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE, Teflon™, a woven fabric such as Tamarack™, a non-woven fabric, such a felt. Such low friction materials may have a thickness of roughly 0.1-5 mm, but other thicknesses can also be used, depending on the material selected and the performance desired. Possible lubricating materials include oils, polymers, microspheres, or powders. Combinations of the above may be used.

[0079] In one example, the low friction material or lubricating material may be a polysiloxane- containing material. In particular the material may comprise (i) an organic polymer, a polysiloxane and a surfactant; (ii) an organic polymer and a copolymer based on a polysiloxane and an organic polymer; or (iii) a non-elastomeric cross-linked polymer obtained or obtainable by subjecting a polysiloxane and an organic polymer to a crosslinking reaction. Preferred options for such materials are described in WO 2017 / 148958 (the entirety of which is herein incorporated by reference).

[0080] In one example, the low friction material or lubricating material may comprise a mixture of (i) an olefin polymer, (ii) a lubricant, and optionally one or more further agents. Preferred options for such materials are described in WO 2020 / 115063 (the entirety of which is herein incorporated by reference).

[0081] In one example, the low friction material or lubricating material may comprise an ultra high molecular weight (UHMW) polymer having a density of < 960 kg / m3, which UHMW polymer is preferably an olefin polymer. Preferred options for such materials are described in WO 2020 / 115063. In one example, the low friction material or lubricating material may comprise a polyketone. Preferred options for such materials are described in WO 2020 / 260185 (the entirety of which is herein incorporated by reference).

[0082] In some arrangements, it may be desirable to configure the low friction interface such that the static and / or dynamic coefficient of friction between materials forming sliding surfaces at the sliding interface is between 0.001 and 0.3 and / or below 0.15. The coefficient of friction can be tested by standard means, such as standard test method ASTM DI 894.

[0083] The friction reducing means may be provided on, or be an integral part of, one or both of the layers of the helmet 1 that are configured to slide relative to each other. In some examples, helmet layers may be configured to have a dual function, including functioning as a friction reducing means. Alternatively, or additionally, the friction reducing means may be separate from the layers of the helmet 1 that are configured to slide relative to each other, but provided between the layers.

[0084] Instead of the sliding interface, in some examples, a shearing interface may be provided between the layers of the helmet 1 that are configured to move relative to each other. At the shearing interface, a shearing layer shears to enable relative movement between the layers of the helmet 1. The shearing layer may comprise a gel or liquid, which may be retained within a flexible envelope. Alternatively, the shearing layer may comprise two opposing layers connected by deformable elements that deform to enable shearing between the two opposing layers.

[0085] A single shearing layer may be provided that substantially fills the volume between two layers of a helmet. Alternatively, one or more shearing layers may be provided that fill only a portion of the volume between two layers of a helmet, e.g. leaving substantial space around the shearing layers. The space may comprise a sliding interface, as described above. As such, helmets may have a combination of shearing and sliding interfaces. Such shearing layers may act as connectors 5, which are described further below.

[0086] Figs. 1 to 7 schematically show connectors 5. The connectors 5 are configured to connect two layers of the helmet while enabling relative movement, e.g. sliding or shearing, between the layers. Different numbers of connectors 5 may be provided than as shown in Figs. 1 to 7. The connectors 5 may be located at different positions than as shown in Figs. 1 to 7, for example at a peripheral edge of the helmet 1 instead of a central portion.

[0087] Typically, a connector 5 comprises first and second attachment parts respectively configured to attach to first and second parts of the helmet and a deformable part between the first and second attachment parts that enables the first and second attachment parts to move relative to each other to enable movement between the first and second parts of the helmet. Connectors 5 may absorb some impact energy by deforming.

[0088] The specific arrangements of each of the example helmets shown in Figs. 1 to 7 are described below.

[0089] Fig. 1 shows a helmet 1 comprising an outer layer 2, an energy absorbing layer 3 and an interface layer 4. The interface layer 4 is provided as a single layer and comprises comfort padding.

[0090] The helmet 1 of Fig. 1 is configured such that the interface layer 4 is able to slide relative to the energy absorbing layer 3 in response to an impact. A sliding interface is provided between the interface layer 4 and the energy absorbing layer 3.

[0091] A sliding layer 6 is provided on a surface of the energy absorbing layer 3 facing the sliding interface. The sliding layer 6 may be moulded to the energy absorbing layer 3 or otherwise attached thereto. The sliding layer 6 may be formed from a relatively hard material, e.g. relative to the energy absorbing layer 3. The sliding layer 6 is configured to provide friction reducing means to reduce the friction at the sliding interface. This may be achieved by forming the sliding layer 6 from a low friction material, such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE. Alternatively, or additionally, this may be achieved by applying a low friction coating to the sliding layer 6, and / or applying a lubricant to the sliding layer 6.

[0092] Alternatively, or additionally, friction reducing means, to reduce the friction at the sliding interface, may be provided by forming the energy absorbing layer 3 from a low friction material, by applying a low friction coating to the energy absorbing layer 3, and / or applying a lubricant to the energy absorbing layer 3.

[0093] The helmet 1 shown in Fig. 1 also comprises connectors 5 attached to the interface layer 4. The connectors are also connected to the sliding layer 6 to allow relative sliding between the energy absorbing layer 3 and the interface layer 4. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as the energy absorbing layer 3 or the outer layer 2. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1.

[0094] It should be understood that such an arrangement of the energy absorbing layer 3 and the interface layer 4 may be added to any helmet described herein.

[0095] Fig. 2 shows a helmet 1 comprising an outer layer 2, an energy absorbing layer 3 and an interface layer 4. The interface layer 4 is provided as a plurality of independent sections each comprising comfort padding.

[0096] The helmet 1 of Fig. 2 is configured such that the sections of the interface layer 4 are able to slide relative to the energy absorbing layer 3 in response to an impact. A sliding interface is provided between the sections of the interface layer 4 and the energy absorbing layer 3.

[0097] A sliding layer 6 is provided on a surface of the energy absorbing layer 3 facing the sliding interface. The sliding layer 6 may be moulded to the energy absorbing layer 3 or otherwise attached thereto. The sliding layer 6 may be formed from a relatively hard material, e.g. relative to the energy absorbing layer 3. The sliding layer 6 is configured to provide friction reducing means to reduce the friction at the sliding interface. This may be achieved by forming the sliding layer 6 from a low friction material, such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE. Alternatively, or additionally, this may be achieved by applying a low friction coating to the sliding layer 6, and / or applying a lubricant to the sliding layer 6.

[0098] Alternatively, or additionally, friction reducing means, to reduce the friction at the sliding interface, may be provided by forming the energy absorbing layer 3 from a low friction material, by applying a low friction coating to the energy absorbing layer 3, and / or applying a lubricant to the energy absorbing layer 3.

[0099] The helmet 1 shown in Fig. 2 also comprises connectors 5 attached to each independent section of the interface layer 4. The connectors 5 are also attached to the sliding layer 6 to allow relative sliding between the energy absorbing layer 3 and the sections of the interface layer 4. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as the energy absorbing layer 3 or the outer layer 2. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1.

[0100] It should be understood that such an arrangement of the energy absorbing layer 3 and the interface layer 4 may be added to any helmet described herein.

[0101] Fig. 3 shows a helmet 1 comprising an outer layer 2, an energy absorbing layer 3 and an interface layer 4. The interface layer 4 is provided as a single layer and comprises comfort padding 4A attached to a substrate 4B. The substrate 4B may be bonded to the outer side of the comfort padding 4A. Such bonding could be through any means, such as by adhesive or by high frequency welding or stitching.

[0102] The helmet 1 of Fig.3 is configured such that the interface layer 4 is able to slide relative to the energy absorbing layer 3 in response to an impact. A sliding interface is provided between the interface layer 4 and the energy absorbing layer 3.

[0103] The substrate 4B of the interface layer 4 faces the sliding interface. The substrate 4B may be formed from a relatively hard material, e.g. relative to the energy absorbing layer 3 and / or the comfort padding 4A. The substrate 4B is configured to provide friction reducing means to reduce the friction at the sliding interface. This may be achieved by forming the substrate 4B from a low friction material, such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE. Alternatively, or additionally, this may be achieved by applying a low friction coating to the substrate 4B, and / or applying a lubricant to the substrate 4B. In an alternative example, the substrate 4B may be formed from a fabric material, optionally coated with a low friction material.

[0104] Alternatively, or additionally, friction reducing means, to reduce the friction at the sliding interface, may be provided by forming the energy absorbing layer 3 from a low friction material, by applying a low friction coating to the energy absorbing layer 3, and / or applying a lubricant to the energy absorbing layer 3.

[0105] The helmet 1 shown in Fig. 3 also comprises connectors 5 attached to the interface layer 4. The connectors are also connected to the energy absorbing layer to allow relative sliding between the energy absorbing layer 3 and the interface layer 4. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as the outer layer 2. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1

[0106] It should be understood that such an arrangement of the energy absorbing layer 3 and the interface layer 4 may be added to any helmet described herein.

[0107] Fig. 4 shows a helmet 1 comprising an outer layer 2, an energy absorbing layer 3 and an interface layer 4. The interface layer 4 is provided as a plurality of independent sections each comprising comfort padding 4A attached to a substrate 4B. The substrate 4B may be bonded to the outer side of the comfort padding 4A. Such bonding could be through any means, such as by adhesive or by high frequency welding or stitching.

[0108] The helmet 1 of Fig. 4 is configured such that the interface layer 4 is able to slide relative to the energy absorbing layer 3 in response to an impact. A sliding interface is provided between the interface layer 4 and the energy absorbing layer 3.

[0109] The substrate 4B of the sections of the interface layer 4 faces the sliding interface. The substrate 4B may be formed from a relatively hard material, e.g. relative to the energy absorbing layer 3 and / or the comfort padding 4A. The substrate 4B is configured to provide friction reducing means to reduce the friction at the sliding interface. This may be achieved by forming the substrate 4B from a low friction material, such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE. Alternatively, or additionally, this may be achieved by applying a low friction coating to the substrate 4B, and / or applying a lubricant to the substrate 4B. In an alternative example, the substrate 4B may be formed from a fabric material, optionally coated with a low friction material. Alternatively, or additionally, friction reducing means, to reduce the friction at the sliding interface, may be provided by forming the energy absorbing layer 3 from a low friction material, by applying a low friction coating to the energy absorbing layer 3, and / or applying a lubricant to the energy absorbing layer 3.

[0110] The helmet 1 shown in Fig. 4 also comprises connectors 5 attached to the sections of the interface layer 4. The connectors 5 are also connected to the energy absorbing layer 3 to allow relative sliding between the energy absorbing layer 3 and the interface layer 4. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as the outer layer 2. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1

[0111] It should be understood that such an arrangement of the energy absorbing layer 3 and the interface layer 4 may be added to any helmet described herein.

[0112] Fig. 5 shows a helmet 1 comprising an outer layer 2 and an energy absorbing layer 3. Although not shown, an interface layer may additionally be provided.

[0113] The helmet 1 of Fig. 5 is configured such that the outer layer 2 is able to slide relative to the energy absorbing layer 3 in response to an impact. A sliding interface may be provided between the outer layer 2 and the energy absorbing layer 3

[0114] Although not shown, an additional layer may be provided on a surface of the energy absorbing layer 3 facing the sliding interface. The additional layer may be moulded to the energy absorbing layer 3 or otherwise attached thereto. The additional layer may be formed from a relatively hard material, e.g. relative to the energy absorbing layer 3. The additional layer may be configured to provide friction reducing means to reduce the friction at the sliding interface. This may be achieved by forming the additional layer from a low friction material, such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE. Alternatively, or additionally, this may be achieved by applying a low friction coating to the additional layer and / or applying a lubricant to the additional layer.

[0115] Alternatively, or additionally, friction reducing means, to reduce the friction at the sliding interface, may be provided by forming the outer layer 2 from a low friction material, providing an additional low friction layer on a surface of the outer layer 2 facing the sliding interface, by applying a low friction coating to the outer layer 2, and / or applying a lubricant to the outer layer 2.

[0116] The helmet 1 shown in Fig. 5 also comprises connectors 5 attached to the outer layer 2. The connectors 5 are also attached to the energy absorbing layer 3 (or additional layer) to allow relative sliding between the energy absorbing layer 3 and the outer layer 2. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as an interface layer. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1.

[0117] It should be understood that such an arrangement of the outer layer 2 and the energy absorbing layer 3 may be added to any helmet described herein.

[0118] Fig. 6 shows a helmet 1 comprising an outer layer 2 and an energy absorbing layer 3. As illustrated, the energy absorbing layer 3 of the helmet shown in Fig. 6 is divided into outer and inner parts 3A, 3B. Although not shown, an interface layer may additionally be provided.

[0119] The helmet 1 of Fig. 6 is configured such that the outer part 3 A of the energy absorbing layer 3 is able to slide relative to the inner part 3B of the energy absorbing layer 3 in response to an impact. A sliding interface may be provided between the outer part 3 A of the energy absorbing layer 3 and the inner part 3B of the energy absorbing layer 3.

[0120] Although not shown, an additional layer may be provided on a surface of one or both of the inner and outer parts 3 A, 3B of the energy absorbing layer 3 facing the sliding interface. The additional layer may be moulded to the inner or outer parts 3 A, 3B of the energy absorbing layer 3 or otherwise attached thereto. The additional layer may be formed from a relatively hard material, e.g. relative to the energy absorbing layer 3. The additional layer may be configured to provide friction reducing means to reduce the friction at the sliding interface. This may be achieved by forming the additional layer from a low friction material, such as PC, PTFE, ABS, PVC, Nylon, PF A, FEP, PE and UHMWPE.

[0121] Alternatively, or additionally, this may be achieved by applying a low friction coating to the additional layer and / or applying a lubricant to the additional layer. Alternatively or additionally, friction reducing means, to reduce the friction at the sliding interface, may be provided by forming one or both of the inner and outer parts 3 A, 3B of the energy absorbing layer 3 from a low friction material, providing an additional low friction layer on a surface of the inner and outer parts 3 A, 3B of the energy absorbing layer 3 facing the sliding interface, by applying a low friction coating to the inner and outer parts 3 A, 3B of the energy absorbing layer 3, and / or applying a lubricant to the inner and outer parts 3 A, 3B of the energy absorbing layer 3.

[0122] The helmet 1 shown in Fig. 6 also comprises connectors 5 attached to the inner part 3B of the energy absorbing layer 3 (or additional layer). The connectors 5 are also attached to the outer part 3 A of the energy absorbing layer 3 (or additional layer) to allow relative sliding between the inner part 3B of the energy absorbing layer 3 and the outer part 3 A of the energy absorbing layer 3. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as an interface layer. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1.

[0123] It should be understood that such an arrangement of inner and outer parts 3 A, 3B of the energy absorbing layer 3 may be added to any helmet described herein.

[0124] Fig. 11 shows a helmet 1 substantially the same as the helmet 1 shown in Fig. 6. However, in the helmet of Fig. 11, the inner part 3B of the energy absorbing layer 3 is formed in multiple parts 3C and 3D adjacent each other in the circumferential direction of the helmet. These parts 3C and 3D are configured to move relative to each other, as well as to the outer part 3 A of the energy absorbing layer. The parts 3C and 3D may be connected to each other by one or more connectors that allow their relative movement.

[0125] Fig. 7 shows a helmet 1 comprising an outer layer 2 and an energy absorbing layer 3. As shown in Fig. 7, one or more outer plates 7 are mounted to the outer layer 2 of the helmet 1. The outer plates 7 may be formed from a relatively strong and / or rigid material, for example from the same types of materials as from which the outer layer 2 may be formed. Although not shown, an interface layer may additionally be provided. The helmet 1 of Fig. 7 is configured such that the outer plates 7 are able to slide relative to the outer layer 2 in response to an impact. A sliding interface may be provided between the outer plates 7 and the outer layer 2.

[0126] Friction reducing means, to reduce the friction at the sliding interface, may be provided by forming the outer layer 2 and / or the outer plates 7 from a low friction material, providing an additional low friction layer on a surface of the outer layer 2 and / or the outer plates 7 facing the sliding interface, by applying a low friction coating to the outer layer 2 and / or the outer plates 7, and / or applying a lubricant to the outer layer 2 and / or the outer plates 7.

[0127] The helmet 1 shown in Fig. 7 also comprises connectors 5 attached to the outer plates 7. The connectors 5 are also attached to the outer layer 2 to allow relative sliding between the plates 7 and the outer layer 2. Alternatively, or additionally, one or more of the connectors 5 may be connected to another part of the remainder of the helmet 1, such as the energy absorbing layer 3. The connectors 5 may also be connected to two or more parts of the remainder of the helmet 1.

[0128] In such an arrangement, in the event of an impact on the helmet 1, it can be expected that the impact would be incident on one or a limited number of the outer plates 7. Therefore, by configuring the helmet such that the one or more outer plates 7 can move relative to the outer layer 2 and any outer plates 7 that have not been subject to an impact, the surface receiving the impact, namely one or a limited number of outer plates 7, can move relative to the remainder of the helmet 1. In the case of an impact, this may reduce the rotational acceleration of the head of a wearer.

[0129] It should be understood that such an arrangement of outer plates 7 may be added to any helmet described herein, namely an arrangement having a sliding interface between at least two of the layers of the helmet 1.

[0130] Some helmets, such as those shown in Figs. 1 to 6, are configured to cover a top portion of the head and the above described helmet structures are appropriately located in the helmet to cover a top portion of the head. For example, a helmet may be provided to substantially cover the forehead, top of the head, back of the head, and / or temples of the wearer. The helmet may substantially cover the cranium of the wearer. Some helmets may be configured to cover other parts of the head, alternatively or additionally to a top portion. For example, helmets such as the helmet shown in Fig. 8 may cover the cheeks and / or chin of the wearer. Such helmets may be configured to substantially cover the jaw of the wearer. Helmets of the type shown in Fig. 8, are often referred to as full-face helmets. As shown in Fig. 8, cheek pads 30 may be provided on either side of the helmet 1 (i.e. left and right sides). The cheek pads 30 may be arranged within an outer layer 2 of the helmet 1 to protect the side of the face of the wearer from an impact.

[0131] The cheek pads 30 may have the same layered structure as the example helmets described above. For example, the cheek pads 30 may comprise one or more energy absorbing layers as described above, and / or an interface layer as described above, and / or layers that move relative to each other as described above, optionally, layers may be connected by connectors as described above. Alternatively, or additionally, the cheek pads 30 themselves may be configured to move relative to the outer layer 2 and, optionally be connected to the outer layer by connectors as described above.

[0132] Although, the above examples relate to helmets, as stated above, the disclosure may also relate to alternative protective apparel, such as body armour, as shown in Figs. 9 and 10. Body armour 100 may provide protection for other parts of the body, such as the shins, knees, thighs, forearms, elbows, upper arms, shoulders, chest, and back. Individual items of body armour may be provided to protect individual body parts (as shown in Fig. 9), or alternatively may be combined in apparel comprising multiple armoured regions 101 to protect more than one body part (as shown in Fig. 10). Such body armour 100 may be worn for the same activities as helmets, discussed above, including for combat, sports, and motorcycling.

[0133] The body armour 100 may have the same layered structure as the example helmets described above. For example, the body armour 100 may comprise an outer layer 2 as described above, one or more energy absorbing layers 3 as described above, and / or an interface layer as described above, and / or layers that move relative to each other as described above, and / or layers may be connected by connectors 5 as described above. General features of a different type of helmet from those described with reference to Figs. 1 to 8 and 11 will now be described with reference to Figs. 12 and 13.

[0134] Helmets of the type described with reference to Figs. 12 and 13 have an outer layer (or outer shell) 2, which may have any of the features, in any combination, of the outer layer 2 described above with respect to Figs. 1 to 7 and 11. Helmets of the type described with reference to Figs. 12 and 13 may also have outer plates as described with reference to Fig. 7.

[0135] Helmets of the type described with reference to Figs. 12 and 13 may also have an energy absorbing layer 3, which may have any of the features, in any combination, of the energy absorbing layer 3 described above with respect Figs. 1 to 7 and 11. Where used, the layer of energy absorbing material may be provided as a shell over substantially all of the surface of the hard shell facing the wearer’s head, although ventilation holes may be provided. Alternatively or additionally, localised regions of energy absorbing material may be provided between the hard shell and a head mount (described below). For example, a band of energy absorbing material may be provided around a circumference of the wearer’s head (such as around the lower edge of the outer shell) and / or a section of energy absorbing material may be provided to be located above the top of the wearer’s head.

[0136] Fig. 12 schematically depicts a cross-section of a helmet of a different type from those depicted in Figs. 1 to 7 and 11. Fig. 12 shows an example helmet 1 comprising a head mount 20. Although not shown in Figs. 1 to 7 and 11, these example helmets may also comprise a head mount 20. The head mount 20 may be provided to mount the helmet 1 on the head of a wearer. In some arrangements, this may improve the comfort of the wearer.

[0137] The head mount 20 may be provided in any form that can function to contribute to mounting the helmet to the wearer’s head. In some configurations, it may assist in securing the helmet 1 to the wearer’s head but this is not essential. The head mount 20 may be configured to at least partially conform to the head of the wearer. For example, the head mount 20 may be elasticated and / or may comprise an adjustment mechanism for adjusting the size of the interface layer. In an arrangement, the head mount 20 may engage with the top of a wearer’s head. The head mount 20 may be removable. This may enable the head mount 20 to be cleaned and / or may enable the provision of an interface layer that is configured to fit a specific wearer.

[0138] As shown in Fig. 12, the head mount 20 is suspended within the rest of the helmet, e.g. a cavity formed therein for accommodating the head, (e.g. the outer shell 2 and / or optional energy absorbing layer 3) such that an air gap 21 is provided between the rest of the helmet and the head mount 20. The head mount 20 may be connected to the rest of the helmet (e.g. to the outer shell 2 and / or optional energy absorbing layer 3) by connectors 25. Helmets of this type are commonly used for industrial purposes, such as by builders, mineworkers or operators of industrial machinery. However, helmets based on such an arrangement may be used for other purposes.

[0139] In a helmet 1 such as that depicted in Fig. 12, the provision of an air gap 21 between the inner surface of the outer shell 2 and the head mount 20 is intended to ensure that loading caused by an impact on the outer shell 2 is spread across a wearer’s head. In particular, the load is not localised on a point on the wearer’s head adjacent the point of impact on the helmet 1. Instead, the load is spread across the outer shell 2 and, subsequently, spread across the head mount 20 and therefore spread across the wearer’s skull.

[0140] During an impact, some of the energy of the impact may be absorbed by deformation of parts of the helmet, such as the head mount, reducing the size of the air gap. Accordingly, the size of the air gap 21 between the outer shell 2 and the head mount 20 may be chosen to ensure that, under an impact on the helmet below a threshold force that the helmet is designed to withstand, the head mount 20 does not come into contact with the outer shell 2, namely the air gap 21 is not entirely eliminated, such that the impact may be directly transferred from the hard shell to the head mount 20. However, in some example helmets, for impacts above the threshold force, the gap 21 may be eliminated, e.g. at a specification location such as the location of impact, such that the rest of the helmet contacts the head mount 20. Such example helmets may comprise an energy absorbing layer 3, which is provided in the space that would otherwise be empty and forming the air gap 21. In other words, part of the air gap 21 may be replaced by an energy absorbing layer. This may bring the rest of the helmet closer to the head mount 20. In an arrangement, the helmet 1 may be configured such that, in the absence of an impact on the helmet, the separation between the outer shell 2 and the head mount 20 at a location corresponding to the top of the head of a wearer is at least 10 mm, optionally at least 15 mm, optionally at least 20 mm, optionally at least 30 mm, optionally at least 40 mm. The magnitude of the impact that the helmet 1 is designed to withstand, and therefore the size of the air gap 21, may depend upon the intended use of the helmet 1. It should be understood that, depending on the intended use of the helmet the size of the air gap 21 may be different at different locations. For example, the air gap 21 may be smaller at the front, back or side of the helmet than it is at the location corresponding to the top of the head of the wearer.

[0141] In arrangements that include an energy absorbing layer, the energy absorbing layer may contribute to the helmet’s ability to withstand radial impacts. In particular in arrangements in which the energy absorbing material is located within the air gap between the outer shell 2 and the head mount 20 at the location corresponding to the top of the wearer’s head, it will be appreciated that the gap between the head mount and the surface of the energy absorbing layer will be smaller than the gap between the outer shell and the head mount, and may be eliminated altogether. Additionally, as a result of the energy absorbing material’s contribution in the event of a radial impact, a smaller gap between the outer shell and the head mount may be required than would be the case in the absence of the energy absorbing material.

[0142] In some arrangements, the head mount 20 may include a head band, or head ring, that at least partially surrounds the wearer’s head. Alternatively, or additionally, the head mount 20 may include one or more straps that extend across the top of the wearer’s head. Alternatively, or additionally, the head mount 20 may include a cap or shell that encapsulates an upper portion of the wearer’s head. Straps or bands that form part of the head mount may be formed from Nylon fabric. Straps or bands that form part of the head mount may be formed from plastics (non-fabric) materials. Other materials may alternatively or additionally be used.

[0143] Fig. 13 shows an example helmet of the type schematically depicted in Fig. 12. As shown, the head mount includes a plurality of straps 31 that extend across the top of the head of a wearer of the helmet 1. The straps 31 may be connected at connection points to the outer shell 2 by any of a plurality of known methods. For example, the outer shell 2 may be moulded to include sockets into which connectors 25 may be inserted.

[0144] In the arrangement depicted in Fig. 13, the head mount 20 is formed from two straps 31 that each extend between a pair of connectors 25 positioned such that the straps 31 extend across the head of the wearer of the helmet. For example, a first strap 31 may extend from a rear left position to a forward right position and a second strap 31 may extend from a rear right position to a forward left position. However, it should be appreciated that many other arrangements may be used. For example, additional straps may be provided, such that there are three, four or more straps extending across the top of the head of the wearer. An additional strap may be provided extending from left to right. A further additional strap may be provided extending from front to back. Similarly, the position of the connection points of the straps 31 to the remainder of the helmet 1 may be different from that depicted in Fig. 13.

[0145] In an arrangement where different straps 31 are in proximity to each other, for example, at the top of the wearer’s head, the straps 31 may not be connected to each other, permitting some movement of one strap relative to another. In other arrangements, the straps 31 may be connected to each other where they cross. In a further arrangement, the head mount may include one or more straps that extend from a connection point to the remainder of the helmet 1 to a point at which it is connected to other straps, for example, at a location corresponding to the top of the head of a wearer of the helmet. Finally, as noted above, in other arrangements, the head mount may be formed from components other than straps, for example from a cap or shell that can be mounted to the top of the head of the wearer of the helmet 1.

[0146] As shown in Fig. 13, the head mount may include a head ring (or headband) 30. The head ring 30 may surround, and engage with, a circumference of the head of the wearer, as shown in Fig. 10. Alternatively, the head ring may engage at least the forehead of a wearer of the helmet and may surround a portion of the head of the wearer. It should be appreciated that such a head ring 30 may be connected to the helmet 1 separately from the remainder of the head mount, such as straps 31. Alternatively, the head ring 30 may be connected to the helmet 1 by means of the straps 20. As a further alternative, the straps 20 may be connected to the rest of the helmet 1 by means of the head ring 30.

[0147] Further straps, e.g. chin straps, may be provided to secure the helmet 1 to the head of the wearer.

[0148] The present disclosure specifically relates to a sliding part 40 for a helmet (or other protective apparel). The sliding part 40 is configured to provide sliding between an inner part of the helmet and an outer part of the helmet in response to an impact.

[0149] As shown in Figs. 14 and 15, the sliding part 40 comprises an inner layer 42 and an outer layer 41. The inner layer 42 and the outer layer 41 are configured to slide relative to each other at a low friction sliding interface in response to an impact to the helmet, when the sliding part forms part of the helmet.

[0150] The sliding part 40 may comprise parts of the helmet already described above as the inner layer 42 and outer layer 42. For example, in some examples, a first of the inner or outer layers 42, 41 may comprise the outer shell 2, energy absorbing layer 3 or interface layer 4. The other of the inner or outer layers 42, 42 may comprise another of the outer shell 2, energy absorbing layer 3 or interface layer 4 configured to slide relative to the one of the outer shell 2, energy absorbing layer 3 or interface layer 4 forming the first of the inner or outer layers 42, 41. Alternatively, the other of the inner or outer layers 42, 41 may comprise only a part of the outer shell 2, energy absorbing layer 3 or interface layer 4 configured to slide relative to the one of the outer shell 2, energy absorbing layer 3 or interface layer 4 forming the first of the inner or outer layers 42, 41. Alternatively still, the one or both of the inner or outer layers 42, 41 may comprise an intermediate layer between two of the outer shell 2, energy absorbing layer 3 or interface layer 4.

[0151] Alternatively, the inner and outer layers 42, 41 may both form part of one of the outer shell 2, the energy absorbing layer 3 or the interface layer 4. Accordingly, these parts may be divided into inner and outer sub-parts that slide relative to each other. In some examples, the sliding part 40 may form the interface layer 4 of the helmet, with the inner and outer layers 42, 41 being different layers forming part of the interface layer. Such examples are shown in Figs. 16 to 18. Fig. 18 shows a specific example in which the interface layer is connected to an energy absorbing layer 3, by connectors 5. As sliding occurs within the interface layer 4, i.e. internally, the connectors 5 do not need to enable sliding between the interface layer 4 and the energy absorbing layer 3 (e.g. as shown in the example helmets of Figs. 1 to 4). However, such sliding can additionally be provided, as can the sliding described in relation to the examples of Figs. 5 to 13.

[0152] The low friction interface between the inner and outer layers may be provided in any of the ways described above in relation to the examples of Figs. 1 to 13.

[0153] As shown in Figs. 14 and 15, the inner layer 42 and the outer layer 41 are bonded at one or more discrete bonding locations 43. Fig. 14 shows the inner and outer layers 42, 41 spaced apart, with arrows indicating the bonding locations 43, where the inner layer 42 and the outer layer 41 are bonded. After bonding, the inner and outer layers 42, 41 may be close to each other or in contact with each other, as shown in Fig. 15. The inner layer 42 and outer layer 41 may be in contact with each other at the bonding locations 43, for example. The inner layer 42 and outer layer 41 may be compressed together at the bonding locations 43, for example.

[0154] The bonding is configured to break when a shearing force between the inner layer 42 and the outer layer 41 exceeds a threshold, such that the sliding is permitted at or above the threshold force, but restricted at the bonding locations by the bonding below the threshold force.

[0155] Bonding is provided at one or more discrete bonding locations 43. The term discrete may refer to a distinct and separate bonding location 43. The bonding locations 43 may not be provided across substantially all of the sliding part 40. The bonding locations 43 may be localised to one or more specific regions of the sliding part 40, each specific region forming a minor proportion of the surface the inner layer 42 or the outer layer 41, preferably less than 50%, or less than 25% of the surface of the inner layer 42 or the outer layer 41. A number of bonding locations, e.g. one to five, may be clustered within each specific region, for example. As shown in Fig. 17, three bonding locations 43 are provided in a specific region corresponding to the top of the head. The majority of the sliding part 40, in particular the surface the inner layer 42 or the outer layer 41 may be devoid of bonding.

[0156] The dimensions of the bonding locations 43 may be substantially smaller than the dimensions of the inner layer 42 and / or outer layer 41 respectively, in two orthogonal directions. For example, the bonding locations should not substantially span one of the dimensions of the inner layer 42 and / or outer layer 41, e.g. when in situ within the helmet.

[0157] The bonding locations 43 may comprise one or more bonding points having two orthogonal dimensions (in a plane of the inner and outer layers) that are substantially the same size. For example, the bonding points may be substantially circular or regular- polygonal in shape. Alternatively, the bonding locations 43 may comprise one or more bonding strips having two orthogonal dimensions (in a plane of the inner and outer layers), one of the two orthogonal dimensions being substantially larger than the other. For example, the bonding points may be substantially oval or rectangular in shape.

[0158] The inner layer 42 and / or the outer layer 41 may respectively comprise a central portion 46 and an edge portion 47. The edge portion 47 may be arranged at a perimeter of the inner layer 42 and / or the outer layer 41 respectively and surrounding the central portion 46. The one or more bonding locations 43 may be arranged in the central portion 46 of the inner layer 42 and / or the outer layer 41 respectively. Fig. 17 illustrates this in the context of an example described further below. As shown in Fig. 17, edge portions 47 may also include edges (perimeter) of cut-out sections, as well as outermost perimeter edges defining the overall shape of the inner and outer layers 42, 41. The central portion 46 not only includes the portion of the sliding part 40 corresponding to the bonding locations 43 shown in Fig. 17, which also happens to be relatively central to the sliding part 40 in general, but also includes other portions of the sliding part 40 between the edge portions, such as those provided in the arm-like projections in the upper section, or lower-most section of the sliding part 40 shown in Fig. 17, e.g. along any of the dashed lines shown in Fig. 17.

[0159] As shown in Fig. 17, the one or more bonding locations 43 may be arranged exclusively in the central portion of the inner layer 42 and / or the outer layer 41 respectively.

[0160] The bonding at the bonding locations 43 may be provided such that the threshold force exceeds typical forces experienced during normal use of the helmet. This may include typical forces experienced when performing an activity for which the helmet is proscribed (e.g. motor racing, motorcycle racing, cycling, horse riding, skating, running, walking, climbing, impacts to the wearer but not the helmet, etc). These may include non-impact forces from the wearer’s movement, g-force or air-resistance. The bonding at the bonding locations 43 may be provided such that the threshold force is lower than a typical impact force. A typical impact force may be a force likely to cause injury to a wearer of the helmet. This threshold force may be different for different helmets designed for different activities. For example, in motorcycle racing, due to high speeds, air-resistance is high and the helmet needs to maintain stability under such forces, but the typical impact force (e.g. with the ground during a crash) is also high. By comparison, for cycling, the threshold force may be significantly lower due to the lower typical forces during normal use and lower typical impact forces.

[0161] The term “injury” as used herein generally refers to blunt force injuries, e.g. specifically those caused by rotational components of an impact, and thus rotation of the head in the example of a helmet, such as brain injuries. Examples of such injuries that may be prevented or mitigated by the helmet include Mild Traumatic Brain Injuries (MTBI) such as concussion, and Severe Traumatic Brain Injuries (STB I) such as subdural haematomas (SDH), bleeding as a consequence of blood vessels rapturing, and diffuse axonal injuries (DAI), which can be summarized as nerve fibres being over stretched as a consequence of high shear deformations in the brain tissue. The term “injury” as used herein does not refer to wounds such as cuts, scratches or lacerations. These may occur from even minor contact forces to the head, below the threshold for injury.

[0162] Accordingly, the bonding at the bonding locations 43 may act to prevent unwanted sliding during normal use, while still enabling sliding to protect the wearer during an impact likely to cause injury to the wearer. Unwanted sliding may be distracting or uncomfortable to the wearer.

[0163] The threshold force may be determined by the bond strengths of each bond at each bonding location 43, as well as how multiple bonding locations are arranged in relation to each other. The threshold force may be different in different directions. For example, two, three, or more bonds may be arranged substantially in a line. The threshold force in such an example may be greater in a direction parallel to the line than in a direction perpendicular to the line.

[0164] Two or more bonding locations may be arranged in a line which corresponds to a direction in which unwanted relative displacement between the inner layer and the outer layer is most probable in normal use of the protective apparel. This may be a front-to-back, side- to-side, or top-to-bottom direction of the protective apparel, for example. Where the protective apparel is a helmet, this may be a front-to-back, side-to-side, or top-to-bottom direction of the helmet.

[0165] Alternatively, or additionally, one or more of the bonding locations 43 may be arranged at locations that have a relatively high amplitude of unwanted relative displacement between the inner layer and the outer layer during normal use. This may be a top, crown, back, front, or side portion, in a helmet, for example.

[0166] Fig. 16 shows an example in which the sliding part is an interface layer 4. As shown, the interface layer 4 may be a comfort padding layer or comfort liner specifically. In this example, the sliding part further comprises a padding layer 44 on an inner side (the upper side in the Figure) of the inner layer 42, such that the inner layer 42 forms an intermediate layer between the padding layer 44 and the outer layer 41. As shown, the sliding part may further comprise a covering layer 45 on an inner side of the padding layer 44, e.g. formed from fabric (such as a mesh fabric).

[0167] The inner layer 42 may comprise a low friction material. The low friction material may facilitate sliding at the sliding interface. The inner layer 42 may comprise a polymer, such as TPU or PC, for example. The inner layer 42 may comprise a low friction coating. The inner layer may comprise any of the low friction materials described above.

[0168] The outer layer 41 may be formed from a fabric. The fabric may be a loop part of hook and loop system. For example, the fabric may be a brushed fabric such as brushed nylon. The outer layer 41 may be configured to attach to an outer part of the helmet (e.g. energy absorbing layer 3 and / or outer shell 2) via a hook and loop connection, the hook part being provided to the outer part and forming the connector 5. The bonding may comprise a weld between the inner and outer layers 42, 41. The bonding may be performed by heat, high frequency or ultrasonic welding, for example. This may be in combination with compression of the inner and outer layers 42, 41 together. Alternatively, bonding may comprise stitching or adhesive.

[0169] The sliding part may be formed by providing the inner layer 42 and the outer layer 41 (e.g. on top of each other) and bonding the inner layer and outer layer at the one or more bonding locations 43. The method of forming the sliding part may further comprise additionally bonding the inner layer 42 and outer layer 41 at the edge portion 47. However, the bonding at the edge portions 47 does not perform the same function as the bonding at the central portion. Instead, the bonding at the edge portion 47 is configured to define and provide structural integrity to the sliding part as a whole. Accordingly, the bonding at the edge portions 47 may not be configured to break at the threshold force required to break the bonding at the bonding locations 43. This may be achieved by the relatively large surface area of the bonding at the edge portions 47 compared to the bonding at the bonding locations 43, e.g. if the same bonding process is used for each.

[0170] Both the bonding at the bonding locations and the bonding formed at the edge portion 47 may be performed in the same step. However, they may alternatively be performed in different steps.

[0171] In an example where the sliding part is a comfort liner, the comfort liner may be formed by bonding the outer layer 41, inner layer 42, padding layer 43 and covering layer 44 together at the edge portion of the comfort liner, and by selectively bonding the padding layer 43 and the covering layer 44 at the central portion of the comfort liner. Fig. 17 shows such an example, in which the comfort liner is removed from the helmet and flattened out, with the edge portions 47 shown in solid lines and the locations of the selective bonding of the padding layer 43 and the covering layer 44 shown by the dashed lines. This selective bonding partitions the padding, e.g. for improved comfort.

[0172] As shown in Fig. 17, the bonding locations 43 may be provided at locations where the padding layer 43 and the covering layer 44 are selectively bonded.

[0173] The method of forming the comfort liner 4 may comprise a first bonding step in which the padding layer 43 and the covering layer 44 are selectively bonded together and a second bonding step in which the outer layer 41, inner layer 42, padding layer 43 and covering layer 44 are bonded together at the edge portion and the one or more bonding locations 43.

[0174] The bonding process may comprise welding, as described above. The padding layer 43 and the covering layer 44 may be placed in welding apparatus for the first step, then the outer layer 41, inner layer 42, padding layer 43 and the covering layer 44 placed in the same, or different welding apparatus for the second step.

[0175] An additional step of cutting out the comfort liner at the edge portion may be performed, e.g. by die cutting.

[0176] Helmets as described above may be used in various activities. These activities include combat and industrial purposes, such as protective helmets for soldiers and hard-hats or helmets used by builders, mine-workers, or operators of industrial machinery for example. Helmets, are also common in sporting activities. For example, protective helmets may be used in ice hockey, cycling, motorcycling, motor-car racing, skiing, snow-boarding, skating, skateboarding, equestrian activities, American football, baseball, rugby, soccer, cricket, lacrosse, climbing, golf, airsoft, roller derby, and paintballing.

[0177] Examples of injuries that may be prevented or mitigated by the helmets described above include Mild Traumatic Brain Injuries (MTBI) such as concussion, and Severe Traumatic Brain Injuries (STB I) such as subdural haematomas (SDH), bleeding as a consequence of blood vessels rapturing, and diffuse axonal injuries (DAI), which can be summarized as nerve fibres being over stretched as a consequence of high shear deformations in the brain tissue.

[0178] Depending on the characteristics of the rotational component of an impact, such as the duration, amplitude and rate of increase, either concussion, SDH, DAI or a combination of these injuries can be suffered. Generally speaking, SDH occur in the case of accelerations of short duration and great amplitude, while DAI occur in the case of longer and more widespread acceleration loads. Variations of the above described examples are possible in light of the above teachings. It is to be understood that the invention may be practiced otherwise and specifically described herein without departing from the spirit and scope of the invention.

Claims

CLAIMS1. A sliding part for protective apparel, the sliding part being configured to provide sliding between an inner part of the protective apparel and an outer part of the protective apparel in response to an impact to the protective apparel, the sliding part comprising: an inner layer; and an outer layer; wherein the inner layer and the outer layer are configured to slide relative to each other at a low friction sliding interface in response to an impact to the protective apparel, when the sliding part forms part of the protective apparel; wherein the inner layer and the outer layer are bonded at one or more discrete bonding locations and the bonding is configured to break when a shearing force between the inner layer and the outer layer exceeds a threshold, such that the sliding is permitted at or above the threshold force, but restricted at the bonding locations by the bonding, below the threshold force.

2. The sliding part of claim 1, wherein the threshold force exceeds typical forces experienced during normal use of the protective apparel.

3. The sliding part of claim 1 or 2, wherein the threshold force is lower than a typical impact force to the protective apparel.

4. The sliding part of any preceding claim, wherein the inner layer and outer layer are in contact with each other at the bonding locations.

5. The sliding part of any preceding claim, wherein the inner layer and outer layer are compressed together at the bonding locations.

6. The sliding part of any preceding claim, wherein the inner layer and / or the outer layer respectively comprise a central portion and an edge portion, the edge portion being arranged at a perimeter of the inner layer and / or the outer layer respectively and surrounding the central portion, and the one or more bonding locations are arranged in the central portion of the inner layer and / or the outer layer respectively.

7. The sliding part of any preceding claim, wherein the one or more bonding locations are arranged exclusively in the central portion of the inner layer and / or the outer layer respectively.

8. The sliding part of any preceding claim, wherein the one or more bonding locations comprise one or more bonding points having two orthogonal dimensions in a plane of the inner and outer layers that are substantially the same size.

9. The sliding part of claim 8, wherein the bonding points are substantially circular or polygonal in shape.

10. The sliding part of any preceding claim, wherein the bonding comprises a weld between the inner and outer layers.

11. The sliding part of any preceding claim, wherein the inner layer comprises a low friction material.

12. The sliding part of any preceding claim, wherein the inner layer comprises a polymer, such as TPU or PC.

13. The sliding part of any preceding claim, wherein the outer layer is formed from a fabric, such as brushed nylon.

14. The sliding part of any preceding claim, wherein the sliding part further comprises a padding layer on an inner side of the inner layer, such that the inner layer forms an intermediate layer between the padding layer and the outer layer.

15. The sliding part of any preceding claim, wherein the sliding part further comprises a covering layer on an inner side of the padding layer.

16. The sliding part of any preceding claim, wherein the sliding part is a comfort liner.

17. The sliding part of claim 16, wherein the comfort liner is formed by bonding the outer layer, inner layer, padding layer and covering layer together at an edge portion of thecomfort liner, the edge portion being arranged at a perimeter of the comfort liner respectively.

18. The sliding part of claim 17, wherein the comfort liner is formed by additionally selectively bonding the padding layer and the covering layer at a central portion of the comfort liner surrounded by the edge portion, wherein the boding locations are provided at locations where the padding layer and the covering layer are selectively bonded.

19. A method of forming the sliding part of any preceding claim, comprising: providing the inner layer and the outer layer; bonding the inner layer and outer layer at the one or more bonding locations.

20. The method of claim 19, wherein the inner layer and / or the outer layer respectively comprise a central portion and an edge portion, the edge portion being arranged at a perimeter of the inner layer and / or the outer layer respectively and surrounding the central portion, and the one or more bonding locations are arranged in the central portion of the inner layer and / or the outer layer respectively; the method further comprising additionally bonding the inner layer and outer layer at the edge portion.

21. The method of claim 20, wherein the bonding at the bonding locations and the edge portion are performed in the same bonding step.

22. The method of any one of claims 19 to 21, wherein: the sliding part is a comfort liner and further comprises a padding layer on an inner side of the inner layer, such that the inner layer forms an intermediate layer between the padding layer and the outer layer, and a covering layer on an inner side of the padding layer; the comfort liner is formed by bonding the outer layer, inner layer, padding layer and covering layer together at the edge portion of the comfort liner, and by selectively bonding the padding layer and the covering layer at the central portion of the comfort liner, wherein the boding locations are provided at locations where the padding layer and the covering layer are selectively bonded.

23. The method of claim 22, comprising a fist bonding step in which the padding layer and the covering layer are selectively bonded together and a second bonding step in which the outer layer, inner layer, padding layer and covering layer are bonded together at the edge portion and the one or more bonding locations.

24. The method of any one of claims 19 to 23, wherein the bonding process comprises welding.

25. The method of claim 24, wherein the welding comprises high frequency welding.

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