Helmet

Abstract

There is provided a helmet (1) comprising: a head-engagement member (8) configured to engage with the occipital region of a head of a wearer; an adjustment mechanism configured to adjust relative positions of the head-engagement member and the front of the helmet to adjust the fit of the helmet relative to the head; and a controller (91) configured to be operated by a user to control the adjustment mechanism, the controller configured to be positioned in the occipital region of the head; wherein the head-engagement member comprises an energy-absorbing member configured to absorb energy associated with an impact directed towards the occipital region of the head.

Description

[0001] HELMET

[0002] The present disclosure relates to a helmet.

[0003] 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 materials, 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.

[0004] 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.

[0005] 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.

[0006] However, existing helmets are often designed to cover an upper part of the head only, with the lower rim of the helmet extending around a circumference of the head, above the ears of the wearer. This is particularly the case for road cycling helmets and industrial helmets (also known as hard hats). Accordingly, part of the head is not afforded protection by the helmet. In particular, the occipital region of the head, which is the lower rear portion of the head, is often left exposed by conventional helmets.

[0007] Some known helmets (for example, US 3,852,821) include padding which is attached to and extends from the rear of the helmet shell. However, this type of padding may not be suitable in helmets including an adjustment mechanism for adjusting the fit of the helmet relative to the head. The present invention aims to provide a helmet that at least partially addresses some of the problems discussed above.

[0008] According to the present invention, there is provided a helmet comprising a headengagement member configured to engage with the occipital region of a head of a wearer; an adjustment mechanism configured to adjust relative positions of the head-engagement member and the front of the helmet to adjust the fit of the helmet relative to the head; and a controller configured to be operated by a user to control the adjustment mechanism. The controller is configured to be positioned in the occipital region of the head. The headengagement member comprises an energy-absorbing member configured to absorb energy associated with an impact directed towards the occipital region of the head.

[0009] The invention is described in detail below, with reference to the accompanying figures, in which:

[0010] Fig. 1 schematically shows a cross-section through a first example helmet;

[0011] Fig. 2 schematically shows a cross-section through a second example helmet;

[0012] Fig. 3 schematically shows a cross-section through a third example helmet;

[0013] Fig. 4 schematically shows a cross-section through a fourth example helmet;

[0014] Fig. 5 schematically shows a cross-section through a fifth example helmet;

[0015] Fig. 6 schematically shows a cross-section through a sixth example helmet;

[0016] Fig. 7 schematically shows a cross-section through a seventh example helmet;

[0017] Fig. 8 schematically shows a cross-section through an eighth example helmet;

[0018] Fig. 9 schematically depicts, in a cross-section, another arrangement of a helmet;

[0019] Fig. 10 depicts the inside of an example of a helmet according to the arrangement depicted in Fig. 9.

[0020] Fig 11 depicts a side view of a helmet including an adjustment mechanism;

[0021] Fig 12 shows a rear view of the helmet of Fig 11;

[0022] Fig 13 shows a side view of another helmet having an adjustment mechanism;

[0023] Fig 14 shows a rear view of the helmet of Fig 13;

[0024] Fig 15 shows the occipital region of the head;

[0025] Fig 16 shows a rear view of a helmet having an energy absorbing member;

[0026] Fig 17 shows a rear view of another helmet having an energy absorbing member;

[0027] Fig 18 shows a rear view of another helmet having an energy absorbing member; Fig 19 shows a side view of another helmet having an energy absorbing member; Fig 20 shows a side view of the helmet of Fig 17.

[0028] 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.

[0029] General features of the example helmets are described below with reference to Figs. 1 to 8.

[0030] 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 and the energy-absorbing member (to be described later) may be the primary energy absorbing elements. Although other elements of the helmet 1 may absorb that energy to a more limited extent, this is not their primary purpose.

[0031] 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.

[0032] 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™.

[0033] 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. As illustrated in Fig. 6, the energy absorbing layer 3 of the helmet 1 may be divided into outer and inner parts 3A and 3B.

[0034] As illustrated in Fig. 8, the energy absorbing layer 3 may be divided into multiple parts arranged adjacent each other in the circumferential direction of the helmet. Fig. 8 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.

[0035] 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 the thickest layer of the helmet 1.

[0036] 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.

[0037] 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.

[0038] 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. 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.

[0039] Figs. 1 to 4 show 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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 4A that is configured to fit a specific wearer.

[0044] Straps, e.g. chin straps, may be provided to secure the helmet 1 to the head of the wearer.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In examples, such as that of Fig. 8, 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.

[0049] 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.

[0050] 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 know 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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).

[0057] 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). 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.

[0058] 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).

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] The specific arrangements of each of the example helmets shown in Figs. 1 to 7 are described below.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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 4 A. 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.

[0087] 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.

[0088] 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

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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. 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] Fig. 8 shows a helmet 1 substantially the same as the helmet 1 shown in Fig. 6. However, in the helmet of Fig. 8, 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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. General features of a different type of helmet from those described with reference to Figs. 1 to 8 will now be described with reference to Figs. 9 and 10.

[0110] Helmets of the type described with reference to Figs. 9 and 10 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 8. Helmets of the type described with reference to Figs. 9 and 10 may also have outer plates as described with reference to Fig. 7.

[0111] Helmets of the type described with reference to Figs. 9 and 10 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 to Figs. 1 to 8. 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.

[0112] Fig. 9 schematically depicts a cross-section a helmet of a different type from those depicted in Figs. 1 to 8. Fig. 9 shows an example helmet 1 comprising a head mount 20. Although not shown in Figs. 1 to 8, 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.

[0113] 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.

[0114] As shown in Fig. 9, 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.

[0115] In a helmet 1 such as that depicted in Fig. 9, 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.

[0116] 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.

[0117] In arrangements that include 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.

[0118] 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.

[0119] Fig. 10 shows an example helmet of the type schematically depicted in Fig. 9. 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.

[0120] In the arrangement depicted in Fig. 10, 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. 10.

[0121] 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.

[0122] As shown in Fig. 10, 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. Further straps, e.g. chin straps, may be provided to secure the helmet 1 to the head of the wearer.

[0123] In the above-described helmets, the outer shell of the helmet (and optionally an energy absorbing layer) are often designed to cover the top portion of the head only. The lower rim of the outer shell (and optionally energy absorbing layer) may sit at a point above the tops of the ears of the wearer, in the vertical direction of the helmet. The lower rim may extend below the tops of the ears in some regions, and may be shaped so as to provide space for the ears. However, even in such arrangements, the lower part of the head is generally not covered by the outer layer, and energy-absorbing layer (if provided). This is the case for many types of helmets, in particular, industrial helmets (also referred to as hard hats) and cycling helmets (especially road cycling helmets).

[0124] Industrial helmets, such as those described with reference to Figs 9 and 10, are designed to protect the head from objects falling from above. Industrial helmets are typically not designed to protect the wearer from tripping or falling. Therefore, the outer shell 2 of the helmet 1 covers the top of the head but not the occipital region of the head.

[0125] In the case of sports helmets, such as road cycling helmets, a region at the back of the head is often reserved for a controller of an adjustment mechanism. An example of such a helmet is illustrated in Figs 13 and 14. As shown in Figs 13 and 14, the occipital region of the head is not covered by the outer layer 2 and energy absorbing layer 3. Instead, the occipital region of the head is left exposed, so as to accommodate controller 91 of adjustment mechanism 9.

[0126] It may therefore be desirable to provide a helmet which provides protection to the occipital region of the head. The occipital region of the head, as defined herein, is the region of the head positioned radially outwards of the occipital bone. Fig 15 shows the position of the occipital bone in the human skull. The occipital region of the head is therefore a region generally at the rear lower part of the head. In the vertical direction, the occipital region extends from the top of the neck up to and including the rear most point of the head.

[0127] Many helmets include an adjustment mechanism for adjusting the fit of the helmet relative to the head. Adjustment mechanisms work by adjusting the relative positions of a head engagement member and the front of the helmet. Figs 11 to 14 show helmets having a head engagement member 8. The head engagement member 8 is configured to engage with the occipital region of the head. This means that the head engagement member 8 is positioned substantially vertically below the lower rim of the helmet at the rearmost point of the helmet. In some arrangements, particularly those without an energy absorbing layer, the head engagement member may partially overlap with the outer layer 2, when viewed from the rear. By adjusting the position of the head engagement member relative to the front of the helmet, in the front-to-back direction of the helmet, the size of a space for the head may be adjusted.

[0128] Where the present description refers to a “head-engagement member”, this means the occipital region head-engagement member which engages the occipital region of the head. Other parts of the helmet may of course engage other parts of the head, such as the forehead or the top of the head. Other parts of the helmet fit system (to be described later) may engage other parts of the head, such as the forehead, top or sides of the head, or any combination thereof.

[0129] Helmets having an adjustment mechanism also include a controller configured to be operated by a user to control the adjustment mechanism. The controller 91 is frequently positioned in the occipital region of the head, for easy access, as shown in Figs 11 to 14. In other words, the controller is positioned substantially vertically below the lower rim of the helmet at the rearmost point of the helmet, in the vertical direction. This means that the controller is located in a region of the head which is often exposed. When a user receives an impact to the back of the head, the controller may be forced into the back of the head and / or could disintegrate, causing harm to the wearer.

[0130] The head engagement member, adjustment mechanism, and controller may together be referred to as a helmet fit system. Further details of the adjustment mechanism will be described later.

[0131] In the present invention, the head-engagement member comprises an energy-absorbing member configured to absorb energy associated with an impact directed towards the occipital region of the head. The energy absorbing member may be configured to absorb impact energy by any of the means as described with reference to an energy absorbing layer 3 of the helmets of Figs 1 to 8. Where the present description refers to an “energyabsorbing member”, this means the energy-absorbing member of the head-engagement member, as opposed to other energy-absorbing elements provided elsewhere in the helmet.

[0132] The energy-absorbing member may be entirely or partially formed from the same material as an energy absorbing layer 3 of any of the helmets described herein. The energyabsorbing member may be entirely of partially formed from a different material (or materials) to the material of an energy absorbing layer 3 of any of the helmets described herein. The energy absorbing member may have a structure that provides energy absorbing characteristics (an energy-absorbing structure). The energy-absorbing structure may be as described above with reference to an energy absorbing layer 3. Optional configurations of energy-absorbing materials and structures of the energy-absorbing member will be discussed later.

[0133] The energy-absorbing member is configured to absorb a meaningful amount of energy associated with an impact that is expected to be survivable for the wearer. Thus, the energy absorbing member is functionally different from a component merely used as comfort padding, as discussed above with regard to Figs 1 to 8. When an impact is received by the energy-absorbing member, for example as a result of an impact generally towards the occipital region of the head of the wearer of the helmet, some of the energy will be absorbed, some of the energy may be redirected / deflected, and some of the energy may be transferred to the head. Of the energy that is absorbed, the majority of the absorbed energy is absorbed by the energy-absorbing member, rather than any other component of the helmet. Similarly, when an impact is received by an energy-absorbing layer of the helmet (as discussed with respect to Figs 1 to 8), the majority of the absorbed energy is absorbed by the energy-absorbing layer, rather than other components such as an outer shell and comfort padding.

[0134] The energy absorbing member may include energy-absorbing material and / or an energyabsorbing structure configured to absorb impact energy. However, the entire energyabsorbing member is not required to be formed from such a material or structure. For example, the energy absorbing member may include an outer layer which is not configured to absorb energy. Such an outer layer may be made from the same material(s) as any of the outer layers 2 described herein. The outer layer of the energy-absorbing member may be formed from the same or different materials as the outer layer 2 of the helmet. The energy-absorbing member may also comprise non-energy-absorbing components for attaching the energy-absorbing member to other parts of the helmet.

[0135] The energy-absorbing member is provided as part of the head-engagement member which engages with the occipital region of the head of a wearer in use. Thus, the energy absorbing member is also provided in the occipital region. The energy-absorbing member is configured to absorb energy associated with impacts directed to the occipital region of the head. Such impacts may be caused by the wearer of the helmet falling so as to hit the rear of the head, or being hit by moving or falling objects, for example. In order to protect the head against such impacts, it is not necessary that the energy absorbing member covers the entire occipital region. The energy-absorbing member may cover a sufficient area of the occipital region of the head such that an impact directed towards this region is likely to be received by the energy absorbing member such that impact energy is absorbed.

[0136] As noted above, the energy-absorbing member is a part of the head engagement member. The position of the head-engagement member is adjustable, relative to the front of the helmet, to adjust the helmet fit. Therefore, the energy-absorbing member is also movable along with the rest of the head-engagement member as part of the adjustment mechanism.

[0137] The position of the energy absorbing member may be arranged so as to protect areas of the occipital region of the head which would usually be left exposed by the outer layer 2 and energy absorbing layer 3. The specific location of the energy-absorbing member may be determined according to the helmet type and intended use. Some example arrangements will now be described.

[0138] In the present description, the left-to-right direction of the helmet corresponds to the left- to-right direction of the head, when the helmet is worn. The front-to-back direction of the helmet corresponds to the front-to-back direction of the head, when the helmet is worn on the head, with the wearer standing in an upright position. The vertical direction of the helmet corresponds to the direction of gravity when the helmet is worn on the head, with the wearer standing in an upright position. It will be appreciated that in use, the head may not be in an upright position, for example in road cycling. Therefore, for consistency, it is assumed that the helmet is orientated as though placed on an upright head in defining the directions of the helmet.

[0139] In some arrangements, the energy absorbing member is provided to the left side and / or the right side of the controller in the left-to-right direction of the helmet. In many arrangements, the energy-absorbing member is provided on both the left side and the right side of the controller. FIGS. 16 to 20 show arrangements in which the energy absorbing member 81 is provided on the left and right sides of the controller 91. The controller 91 of the adjustment mechanism is frequently provided in a central position in the left-to-right direction, at the rear of the head. Therefore, providing the energy absorbing member on both sides of the controller provides protection to an area of the head which is frequently left exposed, whilst still accommodating and allowing access to the controller. In other arrangements, the controller may be provided to one side. In such arrangements, the energy absorbing member may be provided on one side of the controller only.

[0140] Alternatively or additionally, the energy absorbing member may be provided above and / or below the controller in the vertical direction of the helmet. However, in some arrangements, an upper surface of the energy absorbing member may be substantially level with the uppermost point of the controller and / or a lower surface of the energy absorbing member may be substantially level with the lowermost point of the controller.

[0141] FIG.16 shows an example arrangement in which the energy-absorbing member 81 is provided on both sides of the controller 91 in the left-to-right direction of the helmet. In the Fig. 16 example, the upper and lower surfaces of the energy-absorbing member 81 (in the vertical direction) are substantially level with the uppermost and lowermost points of the controller 91, respectively. As shown in FIG. 16 the energy absorbing member 81 may be provided in two separate parts on either side of the controller 91.

[0142] FIG. 17 shows another example arrangement in which the energy absorbing member 81 is provided on both sides of the controller 91 in the left-to-right direction. The energy absorbing member 81 is provided above the controller 91, and the lower surface of the energy absorbing member 81 is substantially level with the lowermost point of the controller 91. As shown in FIG. 17, the shape of the energy absorbing member 81 may be configured to fit with (for example in a jigsaw manner) the shape of the lower rim of the helmet at the rear of the helmet 1. Where there is a gap between the lower rim of the helmet 1 and the controller 91, it may be beneficial to provide the energy absorbing member 81 in the gap so as to protect this area of the head.

[0143] FIG. 18 shows an example arrangement of a helmet 1 in which the energy absorbing member 81 is provided above, below, to the left of, and to the right of the controller 91. In some arrangements, as illustrated in FIG. 18, the energy absorbing member may comprise a single continuous member. Alternatively, the energy absorbing member may be formed of multiple (such as two, three or four) distinct parts formed from an energy-absorbing material and / or having an energy-absorbing structure. The energy absorbing member may comprise holes. For example, a hole may be provided through which the controller 91 may pass through, as shown in FIG. 18. Further holes may be provided, for example to provide ventilation.

[0144] As shown in FIGS. 16 to 18, the energy absorbing member 81 may be provided below the lower rim of the helmet 1 in the vertical direction of the helmet, optionally entirely below the lower rim of the helmet 1. The lower rim of the helmet 1 is the lower rim of the outer layer 2, and optionally the energy absorbing layer 3, which extends around the circumference of the head during use. The energy absorbing member 81 being positioned entirely below the lower rim means that there is no overlap between the energy absorbing member 81 and the outer layer 2 (and optionally energy absorbing layer 3) when viewed from the rear of the helmet 1. However, the uppermost point of the energy absorbing member 81 may be positioned higher than the lower most point of the outer layer 2, for example as shown in FIG. 18, where the energy absorbing member 81 is shaped so as to fit with the shape of the lower rim of the helmet 1.

[0145] Features of the adjustment mechanism will now be described. The adjustment mechanism is configured to adjust relative positions of the head-engagement member and the front of the helmet to adjust the fit of the helmet relative to the head. The adjustment mechanism 9 including the head engagement member 8, controller 91, and optionally arms or a headband (to be described later), may be referred to as a fit system. The fit system may be detachable from the rest of the helmet (i.e. from the outer layer 2 and energy absorbing layer 3). The adjustment mechanism is operable by a controller. In the illustrated arrangements, the controller is configured to be operated manually. However, the controller may alternatively or additionally be configured to be operated with a tool. In any case, the controller is accessible by a user, in order to perform the adjustment. The controller may be a dial, for example as shown in FIGS. 16 to 18. However, alternative types of controller exist, for example an arrangement of slider members positioned in the occipital region of the head, which a user slides with respect to one another to adjust the position of the headengagement member with respect to the front of the helmet.

[0146] FIGS. 11 and 12 show an example of an adjustment mechanism 9, head engagement member 8, and controller 91. In this example, the helmet 1 comprises a headband 30 extending around a circumference of the head. By rotating the dial 91, the length of the headband 30 extending around the head may be increased and decreased. This may be performed by causing parts of the headband to overlap by an increasing, or decreasing, amount. The headband 30 may be part of a head mount 20 as described with respect to FIGS. 9 and 10.

[0147] FIGS. 13 and 14 show another example of an adjustment mechanism 9, head engagement member 8 and controller 91. The adjustment mechanism 9 may comprise a pair of arms extending from the head engagement member 8. The arms extend partially around the left side and right side of the head, respectively. The arms of the adjustment mechanism 9 may together form a band extending partway around a circumference of the head. An end of each band may be fixedly secured to a part of the helmet on each side of the helmet, in the left-to-right direction, respectively. For example, an end of each arm may be fixedly attached to the energy absorbing layer 3 near the lower rim of the helmet 1, towards the front of the helmet and / or above the ears. Rotating the dial 91 may increase or decrease the length of the band (formed by the two arms) extending partway around a circumference of the head. This may work by moving an end of each arm, at the rear of the helmet, toward the controller 91, or away from the controller 91. A ratchet mechanism may be used.

[0148] The material and / or structure of at least part of the energy absorbing member 81 is selected so as to contribute to energy absorption under an impact. As discussed above, the energyabsorbing member may include non-energy-absorbing components such as a hard outer layer and and / or connectors for attachment to other parts of the helmet. A major part of the energy-absorbing member may be formed from or have an energy-absorbing material and / or structure, as described below.

[0149] The energy absorbing member may be configured to deform so as to absorb energy associated with an impact to the energy absorbing member having a radial force component. Deformation of the energy absorbing member may include elastic and / or plastic deformation. Deformation may include crushing, crumpling or collapsing of part of the energy absorbing member. Deformation may include displacement of a fluid (such as air or a liquid) provided within a bag or bladder, as discussed below.

[0150] The energy-absorbing member may be entirely or partially formed from an energyabsorbing material. For example, the energy absorbing member may include an expanded polymer foam, such as expanded polystyrene and / or polypropylene. The energy absorbing member may alternatively or additionally include a non-Newtonian viscoelastic material (optionally foam) such as D3O and / or Poron. The energy-absorbing member may include any of these materials in any combination, in different regions of the energy-absorbing member. The energy-absorbing member may be formed from the same or different material(s) as the energy absorbing layer 3 of the helmet.

[0151] Alternatively, or additionally, the energy absorbing member may include an energyabsorbing structure. An energy-absorbing structure is a structure which absorbs energy associated with an impact primarily by virtue of the design of the structure, as opposed to the bulk material properties of the material(s) forming the structure. In helmets having an energy absorbing layer 3 (as described above with regard to Figs 1 to 8), the energy absorbing layer 3 may include an energy-absorbing structure having any of the features described below, in any combination.

[0152] An energy-absorbing structure may have members (such as walls or struts) which are connected to one another in such a way that they may move or deform relative to one another, when subjected to a compressive force. The members may be connected in a lattice. The structure as a whole may collapse under a compressive load, by virtue of the relative movement and / or deformation of the individual solid elements (walls, struts or projections). The spaces between adjacent walls or struts may be referred to as cells, and may contain air or another fluid. Such energy-absorbing structures may therefore be referred to as collapsible and / or cellular structures. Energy-absorbing structures may absorb energy through the work required to push the air through the spaces created by the structure, and / or the work required to deform the solid elements of the structure (walls, struts or projections).

[0153] The principle of energy absorption of an energy-absorbing structure may be similar to that of energy-absorbing materials, such as expanded polymer foams, which are formed from small air-filled cells. However, an energy-absorbing structure as referred to herein may have a structure which is designed or determined (rather than randomly arising in the process of production of a material such as polystyrene). Energy-absorbing structures may be formed by a process which controls the resultant structure, by moulding (e.g. injection moulding) or additive manufacturing, for example. Energy-absorbing structures may have a repeating pattern (repeating in two dimensions or three dimensions) of cells, which may be filled with air or another fluid. The cells may be completely or partially enclosed by surrounding walls or struts. At least a proportion of the cells may have a diameter greater than 1 mm and up to around 2 cm. An energy-absorbing structure may have cells of different sizes.

[0154] An example energy-absorbing structure is a cellular structure comprising a plurality of hollow tubes. The tubes are arranged in an array such that the open ends of the tubes form opposite outer surfaces of the structure. The tubes may be formed from a polymer. The diameter of the cell inside each tube may be in the range 1 mm to 15 mm. The structure may be arranged so that the longitudinal axes of the tubes face the outer surface of the energy-absorbing member, with the open ends of the tubes forming the outer surface (which may optionally be covered by a hard outer layer, as discussed above). In this way, an impact received by the energy-absorbing member may cause the tubular structure to collapse or crumple, with the compressive force applied along the longitudinal direction of the tubes, to maximise energy absorption by the structure.

[0155] The walls of such cellular or tubular structures may be formed by assembling a plurality of individual tubes, or by forming the walls surrounding the cells in any other manner. For example, such a structure may be formed by stacking layers of material, and joining adjacent layers to one another in certain areas and not others, so that the layers can separate from one another in places so as to form expanded cells (similar to how corrugated cardboard is formed). Such structures may also be formed by additive manufacturing or moulding, such as injection moulding.

[0156] The energy absorbing member may have an open structure which allows air to flow through the energy absorbing member. An example of such an arrangement is shown in Fig. 16. Such an arrangement may contribute to airflow so as to help the wearer to stay cool. Collapsible cellular 3D structures in particular may be chosen so as to provide this effect.

[0157] The energy absorbing member may alternatively or additionally include at least one inflatable airbag and / or fluid filled bladder. For example, any of the energy-absorbing members depicted in Figs. 16 to 20 may be configured as one or more fluid-filled bladders. The bladder may be formed from a material which is soft, pliable, flexible and / or elastic. The material of the bladder may be a polymer or elastomer, and / or may be a film. The bladder may define a closed compartment which is filled with a fluid. The fluid may be air. The fluid may be a liquid or gel configured to absorb energy from compressive forces.

[0158] The stiffness of the controller 91 under compressive forces may be greater than the stiffness of the energy absorbing member 81 under compressive forces. This means that the amount of compressive force required to deform the energy absorbing member is less than the amount of compressive force required to deform the controller. As noted above, the energy absorbing member may include non-energy absorbing components, such as a hard outer layer and / or parts for attaching the energy absorbing member to the rest of the helmet. However, although the energy absorbing member may include parts of varying stiffness under compressive loads, the stiffness of the energy absorbing member as a whole is less than that of the controller. Under an impact to the occipital region of the head, the controller 91, which is not designed to absorb energy, may transfer the impact energy to the back of the head by being forced into the head, and / or may disintegrate.

[0159] The stiffness of the energy absorbing member 81 as a whole may be selected such that a meaningful amount of energy may be absorbed under an impact which is expected to be survivable for the wearer (as discussed above). The energy absorbing member 81 may have a structure which results in the component having a lower stiffness than the bulk material, and makes the component liable to deform, rather than relying on the bulk properties of the material from which it is made, as discussed above. Therefore, the material of the energy absorbing member may be the same as the material of the controller, which may facilitate manufacture and / or disposal at the end of the life of the product.

[0160] It will be appreciated that, if the controller disintegrates, some energy will be absorbed by the disintegration of the controller. However, such disintegration may be harmful to the wearer. In contrast, the energy-absorbing member is designed to absorb energy in a manner which is not harmful to the wearer, such as by any of the energy-absorbing means discussed above.

[0161] As already noted, the energy-absorbing member 81 may include an outer layer. The outer layer of the energy-absorbing member may be formed from any of the materials noted above in respect of outer layers of helmets, as discussed with reference to Figs. 1 to 8. The outer layer of the energy-absorbing member may provide rigidity to the energy-absorbing member. This may help spread the impact energy over a larger area of the energyabsorbing member. The outer layer of the energy-absorbing member may also provide protection against objects that might pierce the energy-absorbing member. Accordingly, the outer layer of the energy-absorbing member may be a relatively strong and / or rigid layer, e.g. compared to the energy-absorbing part of the energy-absorbing member. The outer layer of the energy-absorbing member may be a relatively thin layer, e.g. compared to the energy absorbing part of the energy-absorbing member. The outer layer of the energy-absorbing member may be an outer shell.

[0162] The energy absorbing member may be configured as one or more energy absorbing pads. The pad (or pads) may have an inner surface which may be curved so as to substantially conform to the shape of the head radially beneath. The pad may have an outer surface, opposite the inner surface, which may have approximately the same curvature as the inner surface. As noted above, the energy-absorbing member may include a relatively hard outer layer. This may be provided so as to substantially cover the outer surface of the energy absorbing member. Any of the energy-absorbing members referred to herein may be configured as one or more pads.

[0163] The width of the energy absorbing member may be narrower than the width of the helmet in the left-to-right direction at the widest point of the helmet. Examples of such arrangements are illustrated in Figs. 17 and 18. This arrangement may contribute to the streamlined configuration of the helmet and therefore may be particularly desirable in cycling helmets or other sports helmets. For example, the total width of the energyabsorbing member in the left-to-right direction of the helmet may be less than 80%, less than 70%, or less than 60% of the width of the helmet at its widest point.

[0164] The energy absorbing member may be configured so as not to extend beyond the rearmost point of the rest of the helmet in the front-to-back direction of the helmet. Such an arrangement is illustrated in Figs. 19 and 20. This configuration may contribute to the streamlined nature of the helmet. Alternatively, the energy absorbing member may extend beyond the rearmost point of the rest of the helmet, so as to further increase its energyabsorbing capacity.

[0165] A low friction interface may be provided between at least a part of the energy absorbing member and the occipital region of the head, so as to allow at least a part of the energy absorbing member (and optionally the whole energy-absorbing member) to slide relative to the head under an impact having a tangential force component. The energy absorbing member is principally designed to absorb energy associated with radial impact. However, a low friction interface may be provided between the energy absorbing member, or a part such as a surface of the energy absorbing member, and the head in any of the ways described with respect to the helmets of Figs. 1 to 8.

[0166] The energy absorbing member of the invention may be provided in any of the helmets described herein. The energy absorbing member may be provided in a helmet comprising an outer shell and an energy absorbing layer located radially inwards of the outer shell, such as any of the helmets described with respect to Figs. 1 to 8. Further helmets having an outer layer and an energy absorbing layer are described with respect to Figs. 13, 14, 17, 18 and 20. Helmets described with respect to these Figs, may have any combination of the features described with respect to Figs. 1 to 8. The features of the adjustment mechanism described with respect to Figs. 13 and 14, and the energy absorbing member described with respect to Figs. 17, 18 and 20 may be provided (in any combination) in any of the helmets discussed with respect to Figs 1 to 8. The energy absorbing member of the invention may also be included in a helmet having an outer shell and a head mount configured to conform to the head of a wearer, wherein the head mount comprises straps extending across the top of the head, and an air gap is provided between the head mount and the outer shell. Examples of such helmets are illustrated in Figs 11, 12, 16 and 19. The helmets described with respect to Figs 11, 12, 16 and 19 may have any combination of the features described with respect to FIGS. 9 and 10. The features of the adjustment mechanism and energy absorbing member described with respect to Figs. 11, 12, 16 and 19 may be provided (in any combination) in helmets of the type discussed with respect to Figs. 9 and 10.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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 helmet comprising: a head-engagement member configured to engage with the occipital region of a head of a wearer; an adjustment mechanism configured to adjust relative positions of the headengagement member and the front of the helmet to adjust the fit of the helmet relative to the head; and a controller configured to be operated by a user to control the adjustment mechanism, the controller configured to be positioned in the occipital region of the head; wherein the head-engagement member comprises an energy-absorbing member configured to absorb energy associated with an impact directed towards the occipital region of the head.

2. The helmet of claim 1, wherein the energy-absorbing member is provided on the left side and / or right side of the controller in the left-to-right direction of the helmet.

3. The helmet of claim 1 or 2, wherein the energy-absorbing member is provided above the controller in the vertical direction of the helmet, or an upper surface of the energy-absorbing member is substantially level with the uppermost point of the controller in the vertical direction of the helmet.

4. The helmet of any preceding claim, wherein the energy-absorbing member is provided below the controller in the vertical direction of the helmet, or a lower surface of the energy-absorbing member is substantially level with the lowermost point of the controller in the vertical direction of the helmet.

5. The helmet of any preceding claim, wherein the energy-absorbing member is provided below the lower rim of the helmet in the vertical direction of the helmet.

6. The helmet of any preceding claim, wherein the controller is configured to be operated manually.

7. The helmet of any preceding claim, wherein the controller is a dial.

8. The helmet of any preceding claim, wherein the adjustment mechanism is configured to adjust the length of a band extending around a circumference of the head.

9. The helmet of any one of claims 1 to 7, wherein the adjustment mechanism is configured to adjust the length of a band extending partway around a circumference of the head.

10. The helmet of any preceding claim, wherein the stiffness of the controller under compressive forces is greater than the stiffness of the energy-absorbing member under compressive forces.

11. The helmet of any preceding claim, wherein the energy-absorbing member has an open structure which allows air to flow through the energy-absorbing member.

12. The helmet of any preceding claim, wherein the energy-absorbing member is configured as one or more energy-absorbing pads.

13. The helmet of any preceding claim, wherein the width of the energy-absorbing member in the left-to-right direction of the helmet is narrower than the width of the helmet in the left-to-right direction at the widest point of the helmet.

14. The helmet of any preceding claim, wherein the energy-absorbing member does not extend beyond the rearmost point of the rest of the helmet in the front-to-back direction of the helmet.

15. The helmet of any preceding claim, wherein the energy-absorbing member is detachable.

16. The helmet of any preceding claim, further comprising a low-friction interface positioned between at least a part of the energy-absorbing member and the occipital region of the head, which allows at least the part of the energy-absorbing member to slide relative to the head under an impact to the energy-absorbing member having a tangential force component.

17. The helmet of any preceding claim, wherein the energy-absorbing member is configured to deform so as to absorb energy associated with an impact to the energyabsorbing member having a radial force component.

18. The helmet of any preceding claim, further comprising: an outer shell; and an energy-absorbing liner located radially inwards of the outer shell.

19. The helmet of claim 18, further comprising a low-friction interface between the outer shell and the head, which allows the outer shell to slide relative to the head under an impact to the outer shell having a tangential force component.

20. The helmet of any one of claims 1 to 17, further comprising: an outer shell; and a head mount configured to conform to the head of a wearer,wherein the head mount comprises a plurality of straps that extend across the top of the head, and an air gap is provided between the head mount and the outer shell.

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