The present invention relates to connectors between inner and outer parts of an apparatus. In particular the present invention relates to an apparatus, such as a helmet, that may include a sliding interface between two components.
Helmets are known for use 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.
Helmets can be of fixed size or adjustable, to fit different sizes and shapes of head. In some types of helmet, e.g. commonly in ice-hockey helmets, the adjustability can be provided by moving parts of the helmet to change the outer and inner dimensions of the helmet. This can be achieved by having a helmet with two or more parts which can move with respect to each other. In other cases, e.g. commonly in cycling helmets, the helmet is provided with an attachment device for fixing the helmet to the user's head, and it is the attachment device that can vary in dimension to fit the user's head whilst the main body or shell of the helmet remains the same size. In some cases, comfort padding within the helmet can act as the attachment device. The attachment device can also be provided in the form of a plurality of physically separate parts, for example a plurality of comfort pads which are not interconnected with each other. Such attachment devices for seating the helmet on a user's head may be used together with additional strapping (such as a chin strap) to further secure the helmet in place. Combinations of these adjustment mechanisms are also possible.
Helmets are often made of an outer shell, that is usually hard and made of a plastic or a composite material, and an energy absorbing layer called a liner. In other arrangements, such as a rugby scrum cap, a helmet may have no hard outer shell, and the helmet as a whole may be flexible. In any case, nowadays, a protective helmet has to be designed so as to satisfy certain legal requirements which relate to inter alia the maximum acceleration that may occur in the centre of gravity of the brain at a specified load. Typically, tests are performed, in which what is known as a dummy skull equipped with a helmet is subjected to a radial blow towards the head. This has resulted in modern helmets having good energy-absorption capacity in the case of blows radially against the skull. Progress has also been made (e.g. WO 2001/045526 and WO 2011/139224, which are both incorporated herein by reference, in their entireties) in developing helmets to lessen the energy transmitted from oblique blows (i.e. which combine both tangential and radial components), by absorbing or dissipating rotation energy and/or redirecting it into translational energy rather than rotational energy.
Such oblique impacts (in the absence of protection) result in both translational acceleration and angular acceleration of the brain. Angular acceleration causes the brain to rotate within the skull creating injuries on bodily elements connecting the brain to the skull and also to the brain itself.
Examples of rotational injuries include Mild Traumatic Brain Injuries (MTBI) such as concussion, and Severe Traumatic Brain Injuries (STBI) 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.
Depending on the characteristics of the rotational force, 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.
In helmets such as those disclosed in WO 2001/045526 and WO 2011/139224 that may reduce the rotational energy transmitted to the brain caused by oblique impacts, two parts of the helmet may be configured to slide relative to each other following an oblique impact. Connectors may be provided that, whilst connecting the parts of a helmet together, permit movement of the parts relative to each other under an impact.
In order to provide such a helmet, it may be desirable to provide two components that can slide relative to each other, providing a sliding interface. It may also be desirable to be able to provide such a sliding interface without substantially increasing the manufacturing costs and/or effort.
According to an aspect of the disclosure there is provided a connector for connecting inner and outer layers of an apparatus, the connector comprising: an anchor point configured to be connected to one of the inner and outer layers; a resilient portion arranged to at least partially surround the anchor point about a first axis extending in a first direction and connected to the anchor point; a peripheral portion arranged to at least partially surround the resilient portion about a second axis extending in the first direction and connected to the resilient portion, and configured to be connected to the other of the inner and outer layers; and attachment means on a surface of the connector opposite to the anchor point, for attaching the connector to the inner or outer layer not to be connected to the anchor point; wherein the resilient portion is configured to protrude from the peripheral portion in the first direction, in a connected state in which the connector is connected to the inner and outer layers, and deform to allow the anchor point to move relative to the peripheral portion in a direction perpendicular to the first direction.
Optionally, the attachment means is provided on a surface of the peripheral portion. This may improve the stability of a connection arrangement including the connector.
Optionally, the attachment means is a hook and loop attachment means. This may simplify installation of the connector
Optionally, in a non-deformed state, the resilient portion is substantially flat, and the connected state is a deformed state of the resilient portion. This feature may provide a more compact connector and actively pull components of the apparatus together for a more compact apparatus. Alternatively, in a non-deformed state, the resilient portion protrudes from the peripheral portion in the first direction. This feature may provide a connector that is relatively easily installed.
Optionally, the resilient portion extends across a central region of the connector surrounded by the peripheral region.
Optionally, the resilient portion substantially covers the entirety of the central region. This may prevent the ingress of unwanted material, such as dirt, which may interfere with the performance of the connector. Alternatively, the resilient portion comprises multiple sections having gaps therebetween. Optionally, the multiple sections extend in a radial direction relative to the first axis. This may reduce the amount of material required for the connector and/or allow the resiliency of the connector to be more finely controlled.
Optionally, the peripheral portion forms a closed loop. Optionally, the peripheral portion is substantially annular and the second axis passes through the centre of the peripheral portion. These features improve the stability of the connector.
Optionally, the anchor point is aligned with the first axis.
Optionally, the first and second axes are coincident.
Optionally, the resilient portion and the peripheral portion have rotational symmetry about the coincident first and second axes. Such an arrangement may ensure the connector performs uniformly regardless of the direction of sliding movement.
Optionally, the peripheral portion is formed from a rigid material.
Optionally, the connector further comprises an insert formed from a rigid material, the insert being configured to be inserted into the peripheral portion to prevent the peripheral portion from deforming. This may improve the stability of the connector.
Optionally, the peripheral portion is formed from a resilient material.
Optionally, the resilient portion and the peripheral portion are integrally formed. This may provide a more robust connector and/or may reduce the number of parts required.
Optionally, the anchor point comprises a snap-fit connector configured to snap fit with the inner or outer layer. This may provide a relatively simple mechanism for connection, reducing installation time, and/or a relatively robust connection mechanism.
Optionally, the connector further comprises a cap configured to cover a central region of the connector surrounded by the peripheral region so as to prevent the ingress of unwanted material to the central region.
Optionally, the connector further comprises protrusions connected to the peripheral portion and configured to anchor the peripheral portion in the inner or outer layer. This may provide a stronger connection between the connector and the apparatus.
According to a second aspect of the invention there is provided an apparatus comprising: an inner layer; an outer layer; a sliding interface between the inner layer and the outer layer; and the connector according to the first aspect connected to the inner and outer layers so as to allow relative sliding between the inner and outer layers at the sliding interface, in response to an impact to the apparatus.
Optionally, the peripheral portion is arranged between the inner and outer layers. This may improve the ease of installation of the connector, e.g. allowing retrofitting to an apparatus without significantly redesigning the apparatus.
Optionally, the inner or outer layer comprises a further attachment means complementary to the attachment means of the connector.
Optionally, the apparatus is a helmet.
Optionally, the outer layer is a hard shell and the inner layer is an energy absorbing layer. Alternatively, the inner layer is a hard shell and the outer layer comprises one or more plates connected to the hard shell. Alternatively, both the inner layer and the outer layer are energy absorbing layers. Alternatively, the outer layer is an energy absorbing layer and the inner layer is an interface layer, configured to interface with a wearer's head. Optionally, the interface layer comprises comfort padding.
The invention is described in detail below, with reference to the accompanying figures, in which:
The proportions of the thicknesses of the various layers in the helmets depicted in the figures have been exaggerated in the drawings for the sake of clarity and can of course be adapted according to need and requirements.
Protective helmet 1 is constructed with an outer shell 2 and, arranged inside the outer shell 2, an inner shell 3 that is intended for contact with the head of the wearer.
Arranged between the outer shell 2 and the inner shell 3 is a sliding layer 4 (also called a sliding facilitator or low friction layer), which may enable displacement between the outer shell 2 and the inner shell 3. In particular, as discussed below, a sliding layer 4 or sliding facilitator may be configured such that sliding may occur between two parts during an impact. For example, it may be configured to enable sliding under forces associated with an impact on the helmet 1 that is expected to be survivable for the wearer of the helmet 1. In some arrangements, it may be desirable to configure the sliding layer 4 such that the coefficient of friction is between 0.001 and 0.3 and/or below 0.15.
Arranged in the edge portion of the helmet 1, in the
Further, the location of these connecting members 5 can be varied (for example, being positioned away from the edge portion, and connecting the outer shell 2 and the inner shell 3 through the sliding layer 4).
The outer shell 2 is preferably relatively thin and strong so as to withstand impact of various types. The outer shell 2 could be made of a polymer material such as polycarbonate (PC), polyvinylchloride (PVC) or acrylonitrile butadiene styrene (ABS) for example. Advantageously, the polymer material can be fibre-reinforced, using materials such as glass-fibre, Aramid, Twaron, carbon-fibre or Kevlar.
The inner shell 3 is considerably thicker and acts as an energy absorbing layer. As such, it is capable of damping or absorbing impacts against the head. It can advantageously be made of foam material like expanded polystyrene (EPS), expanded polypropylene (EPP), expanded polyurethane (EPU), vinyl nitrile foam; or other materials forming a honeycomb-like structure, for example; or strain rate sensitive foams such as marketed under the brand-names Poron™ and D3O™. The construction can be varied in different ways, which emerge below, with, for example, a number of layers of different materials.
Inner shell 3 is designed for absorbing the energy of an impact. Other elements of the helmet 1 will absorb that energy to a limited extent (e.g. the hard outer shell 2 or so-called ‘comfort padding’ provided within the inner shell 3), but that is not their primary purpose and their contribution to the energy absorption is minimal compared to the energy absorption of the inner shell 3. Indeed, although some other elements such as comfort padding may be made of ‘compressible’ materials, and as such considered as ‘energy absorbing’ in other contexts, it is well recognised in the field of helmets that compressible materials are not necessarily ‘energy absorbing’ in the sense of absorbing a meaningful amount of energy during an impact, for the purposes of reducing the harm to the wearer of the helmet.
A number of different materials and embodiments can be used as the sliding layer 4 or sliding facilitator, for example oil, Teflon, microspheres, air, rubber, polycarbonate (PC), a fabric material such as felt, etc. Such a layer 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. The number of sliding layers and their positioning can also be varied, and an example of this is discussed below (with reference to
As connecting members 5, use can be made of, for example, deformable strips of plastic or metal which are anchored in the outer shell and the inner shell in a suitable manner.
As can be seen, the force K gives rise to a displacement 12 of the outer shell 2 relative to the inner shell 3, the connecting members 5 being deformed. Significant reductions in the torsional force transmitted to the skull 10 can be obtained with such an arrangement. A typical reduction may be roughly 25% but reductions as high as 90% may be possible in some instances. This is a result of the sliding motion between the inner shell 3 and the outer shell 2 reducing the amount of energy which is transferred into radial acceleration.
Sliding motion can also occur in the circumferential direction of the protective helmet 1, although this is not depicted. This can be as a consequence of circumferential angular rotation between the outer shell 2 and the inner shell 3 (i.e. during an impact the outer shell 2 can be rotated by a circumferential angle relative to the inner shell 3).
Other arrangements of the protective helmet 1 are also possible. A few possible variants are shown in
In
An interface layer 13 (also called an attachment device) is provided, to interface with (and/or attach helmet 1 to) a wearer's head. As previously discussed, this may be desirable when energy absorbing layer 3 and rigid shell 2 cannot be adjusted in size, as it allows for the different size heads to be accommodated by adjusting the size of the attachment device 13. The attachment device 13 could be made of an elastic or semi-elastic polymer material, such as PC, ABS, PVC or PTFE, or a natural fibre material such as cotton cloth. For example, a cap of textile or a net could form the attachment device 13.
Although the attachment device 13 is shown as comprising a headband portion with further strap portions extending from the front, back, left and right sides, the particular configuration of the attachment device 13 can vary according to the configuration of the helmet. In some cases the attachment device may be more like a continuous (shaped) sheet, perhaps with holes or gaps, e.g. corresponding to the positions of vents 7, to allow air-flow through the helmet.
A sliding facilitator 4 is provided radially inwards of the energy absorbing layer 3. The sliding facilitator 4 is adapted to slide against the energy absorbing layer or against the attachment device 13 that is provided for attaching the helmet to a wearer's head.
The sliding facilitator 4 is provided to assist sliding of the energy absorbing layer 3 in relation to an attachment device 13, in the same manner as discussed above. The sliding facilitator 4 may be a material having a low coefficient of friction, or may be coated with such a material.
As such, in the
However, it is equally conceivable that the sliding facilitator 4 may be provided on or integrated with the outer surface of the attachment device 13, for the same purpose of providing slidability between the energy absorbing layer 3 and the attachment device 13. That is, in particular arrangements, the attachment device 13 itself can be adapted to act as a sliding facilitator 4 and may comprise a low friction material.
In other words, the sliding facilitator 4 is provided radially inwards of the energy absorbing layer 3. The sliding facilitator can also be provided radially outwards of the attachment device 13.
When the attachment device 13 is formed as a cap or net (as discussed above), sliding facilitators 4 may be provided as patches of low friction material.
The low friction material may be a waxy polymer, such as PTFE, ABS, PVC, PC, Nylon, PFA, EEP, PE and UHMWPE, or a powder material which could be infused with a lubricant. The low friction material could be a fabric material. As discussed, this low friction material could be applied to either one, or both of the sliding facilitator and the energy absorbing layer.
The attachment device 13 can be fixed to the energy absorbing layer 3 and/or the outer shell 2 by means of fixing members 5, such as the four fixing members 5a, 5b, 5c and 5d in
According to the arrangement shown in
A frontal oblique impact I creating a rotational force to the helmet is shown in
In general, in the helmets of
Connectors that may be used within a helmet are described below. It should be appreciated that these connectors may be used in a variety of contexts and are not to be limited to use within helmets. For example, they may be used in other devices that provide impact protection, such as body armour or padding for sports equipment. In the context of helmets, the connectors may, in particular, be used in place of the previously known connecting members and/or fixing members of the arrangements discussed above.
In an arrangement, the connector may be used with a helmet 1 of the type shown in
The liner 15 may be removable. This may enable the liner to be cleaned and/or may enable the provision of liners that are modified to fit a specific wearer.
Between the liner 15 and the energy absorbing layer 3, there is provided an inner shell 14 formed from a relatively hard material, namely a material that is harder than the energy absorbing layer 3. The inner shell 14 may be moulded to the energy absorbing layer 3 and may be made from any of the materials discussed above in connection with the formation of the outer shell 2. In alternative arrangements, the inner shell 14 may be formed from a fabric material, optionally coated with a low friction material.
In the arrangement of
As shown, the liner 15 may be connected to the remainder of the helmet 1 by way of one or more connectors 20, discussed in further detail below. Selection of the location of the connectors 20 and the number of connectors 20 to use may depend upon the configuration of the remainder of the helmet.
In an arrangement such as shown in
The sections of comfort padding 16 may have a sliding interface provided between the sections of comfort padding 16 and the remainder of the helmet 1. In such an arrangement, the sections of comfort padding 16 may provide a similar function to that of the liner 15 of the arrangement shown in
It should also be appreciated that the arrangement of
In
In
In another arrangement, the connector may be used with a helmet 1 of the type shown in
In yet another arrangement, the connector may be used with a helmet 1 of the type shown in
The outer plates 17 may be mounted to the relatively hard layer 2 in a manner that provides a low friction interface between the outer surface of the relatively hard layer 2 and that least a part of a surface of the outer plate 17 that is in contact with the outer surface of the relatively hard layer 2, at least under an impact to the outer plate 17. In some arrangements, an intermediate low friction layer may be provided between the hard layer 2 and the plates 17
In addition, the manner of mounting the outer plates 17 may be such that, under an impact to an outer plate 17, the outer plate 17 can slide across the relatively hard layer 2 (or intermediate low friction layer). Each outer plate 17 may be connected to the remainder of the helmet 1 by one or more connectors 20.
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 17. Therefore, by configuring the helmet such that the one or more outer plates 17 can move relative to the relatively hard layer 2 and any outer plates 17 that have not been subject to an impact, the surface receiving the impact, namely one or a limited number of outer plates 17, can move relative to the remainder of the helmet 1. In the case of an oblique impact or a tangential impact, this may reduce the transfer of rotational forces to the remainder of the helmet. In turn, this may reduce the rotational acceleration imparted on the brain of a wearer of the helmet and/or reduce brain injuries.
Possible arrangements of connectors 20 will now be described. For convenience the connectors will generally be described as connecting an interface layer (e.g. liner 15 or padding layer 16) to an energy absorbing layer of a helmet, such as is shown in
The connector 20 generally comprises an anchor point 21 configured to be connected to the interface layer of a helmet. The connector 20 further comprises a resilient portion 22 arranged to at least partially surround the anchor point 21, about a first axis A extending in a first direction, and connected to the anchor point 21. A peripheral portion 23 of the connector 20 is arranged to at least partially surround the resilient portion 22, about a second axis B extending in the first direction, and connected to the resilient portion 22. The peripheral portion 23 is also configured to be connected to the energy absorbing layer 3 of the helmet and/or an intermediate low friction layer 4 associated with the energy absorbing layer 3. The connector 20 further comprises attachment means 24, on a surface of the connector opposite to the anchor point 21, for attaching the connector 20 to the energy absorbing layer 3. The resilient portion 22 is configured to deform to allow the anchor point 21 to move relative to the peripheral portion 23 in a direction perpendicular to the first direction.
In the example shown in
However, alternative arrangement are possible, for example, the anchor point 21 may be connected to the energy absorbing layer 3 by glue, a hook-and-loop arrangement or a magnet instead.
As shown in
It should be understood that the term anchor point refers generally to any structure configured to attach (or anchor) the connector 20 to a part of the helmet 1. However, in some embodiments, the anchor point 21 may be relatively small compared to the connector 20 so as to be located substantially at a point on the connector 20, e.g. a point on the first axis A.
The peripheral portion 23 is primarily provided for connection of the connector 20 to the energy absorbing layer 3. However, the peripheral portion 23 may also provide strength and stability to the connector 20. Accordingly, the peripheral portion may be formed from a relatively rigid material compared to the material forming the resilient portion 22. The rigid material may be configured to retain its shape, under an impact to the helmet 1, while the resilient portion 22 deforms under the same impact. The rigid material may be, for example, PTFE, ABS, PVC, PC, Nylon, PFA, EEP, PE, UHMWPE, and metal.
As shown in
As shown in
The peripheral portion 23 may have a substantially flat outer surface (i.e. facing away from the anchor point 21). This surface may be configured to connect to the energy absorbing layer 3. The flat surface may be in a plane perpendicular to the first direction.
The attachment means 24 may be provided on a surface of the peripheral portion 23, as shown in
In other examples different attachment means may be provided, such as snap pin(s), magnet(s), or adhesive.
In the example connector 20 of
In the example shown in
In the example shown in
As shown, the resilient portion 21 is substantially cup-shaped. In other words the resilient portion 22 defines a concave region, coinciding with the central region defined by the peripheral portion 23. In this example, the concave region defined by the resilient portion 22 is completely surrounded by the resilient portion 22 about the first axis A. In other words, the resilient portion 22 is continuous, i.e. has no gaps or holes therein. Further, the resilient portion 22 is arranged such that the cup-shape tapers in from the peripheral-portion-side to the anchor-point-side.
As shown in
As shown in
When connected to the helmet 1, the resilient portion 22 may be in a non-deformed or deformed state. The resilient portion 22 is able to deform/further deform to allow the anchor point 21 to move relative to the peripheral portion 23 in a direction perpendicular to the first direction.
As with the previous example connectors 20, when connected, the resilient portion 22 of the present example is configured to protrude from the peripheral portion 23 in the first direction, through the outer shell 2. The resilient portion 22 substantially remains in its non-deformed state when it is connected thus. However, some deformation may occur. The resilient portion 22 is able to deform (or further deform) to allow the anchor point 21 to move relative to the peripheral portion 23 in a direction perpendicular to the first direction.
Further, the anchor point 21 of the present example connector 20 is different to that of the previous example connector 20. In particular, the anchor point of the present example connector comprises a through hole 21 for the insertion of a snap-pin. The interface layer may comprise a corresponding snap-pin housing.
As shown in
As shown in
Generally, the connectors 20 described above may be configured such that the peripheral portion lies substantially in a plane parallel to the layer to which it is attached, i.e. a plane substantially perpendicular to the radial direction of a helmet. The first and/or second axes described above may be configured to extend substantially in the radial direction of a helmet. The connector 20 may permit relative movement between layers substantially perpendicular to the radial direction of a helmet.
Various arrangements are described above for attaching the peripheral portion 23 to the helmet. However, alternatively, the peripheral portion 23 may be part of, or integrally formed with, the energy absorbing layer 3.
Some example helmets, such as those shown in
Some example 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
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. The cheek pads 30 may comprise inner and outer layers that can move relative to each other as described above.
The connectors described above may connect the check pads 30 to a portion of the outer shell 2 of the helmet 1 to enable relative sliding between the cheek pad and the outer shell, or may connect inner and outer layers of the cheek pad 30 to enable sliding between the inner and outer layers.
Although, the above examples relate to cases in which the apparatus is a helmet, the apparatus may be alternative protective apparel. For example, the apparatus may comprise body armour 100 for other parts of the body, such as the shins, knees, thighs, forearms, elbows, upper arms, shoulders, chest and back, as shown in
The body armour 100 may have the same layered structure as the example helmets described above. For example, as shown in
It should be understood that features of each of the examples described above may be combined. For example any one of the above examples may be modified to include features described in relation to any other of the examples. For example, any one of the different arrangements of the peripheral portion 23 and/or resilient portion 22 may be interchanged. Further, any one of the arrangements for aligning or anchoring the peripheral portion in the outer shell 2 may be used with any of the described connectors 20 and in combination with other arrangements. Further still, any type of fastening means may be used to connect the anchor point 21 of any of the above connectors to the helmet 1.
Number | Date | Country | Kind |
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1918754.1 | Dec 2019 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/085816 | 12/11/2020 | WO |