The present invention relates to a pad and padding for protective apparel.
Protective apparel, including helmets and other headgear, 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. Protective apparel is 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.
Some protective apparel are rigorously tested. For example, 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 a dummy skull equipped with a helmet is subjected to a radial blow towards the head. This has resulted in modem helmets, and other apparel having good energy- absorption capacity in the case of a radial impact.
However, it is also important for protective apparel to effectively protect against an oblique impact, which combines both tangential and radial components. This may be achieved by absorbing and/or dissipating rotation energy and/or redirecting rotational energy into translational energy.
In the case of headgear, such oblique impacts result in both translational acceleration and angular acceleration of the brain. Angular acceleration causes the brain to rotate within the skull, which can result in 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.
Protective apparel has been developed that reduces the rotational energy transmitted to the wearer by oblique impacts. In some cases (such as the helmets disclosed in WO 2001/045526 and WO 2011/139224) two parts of the apparel may be configured to slide and/or shear relative to each other following an oblique impact, in order to reduce the rotational energy transmitted to the wearer. Connectors may be provided that, whilst connecting the parts of the apparel together, permit sliding and/or shearing of the parts relative to each other under an impact.
When providing protective apparel that comprises sliding and/or shearing parts, the protective function of the apparel is the primary concern. However, this is often at the expense of the comfort of the wearer, the weight and/or size of the apparel, and the cost (e.g. due to increased cost of materials and/or manufacturing).
It is an aim of the present invention to at least partially improve some of the issues described above.
According to an aspect of the invention there is provided a pad, configured to be attached to an item of protective apparel, the pad having a layered construction comprising, in order: a first support layer; a first padded layer; a first low friction layer; a second low friction layer; a second padded layer; and a second support layer connected to the first support layer so as to hold the other layers of the pad together; wherein: the first and second padded layers are configured to slide relative to each other at a sliding interface located between the first and second low friction layers; and the second support layer is configured to stretch to accommodate the sliding.
According to second aspect of the invention there is provided padding for protective apparel, the padding comprising a plurality of distinct pads integrally formed, each pad having a layered construction comprising, in order: a first support layer; a first padded layer; a first low friction layer; a second low friction layer; a second padded layer; and a second support layer connected to the first support layer so as to hold the other layers of the pad together; wherein: the first and second padded layers are configured to slide relative to each other at a sliding interface located between the first and second low friction layers; and the second support layer is configured to stretch to accommodate the sliding.
In the padding of the second aspect, optionally each pad shares a common first support layer. In the padding of the second aspect, optionally each pad shares a common second support layer. Optionally the common first support layer is connected to the common second support layer between each pad.
According to either aspect, optionally, the first and/or second low friction layers are respectively fixedly attached to the first and second padded layers respectively.
Optionally, the first and/or second low friction layer is a plastic. Optionally, the plastic is polycarbonate.
Optionally, the first support layer is formed from a first fabric. Optionally, the first fabric forms part of a hook-and-loop fastening means.
Optionally, the second support layer is formed from a second fabric.
Optionally, the first and/or second padded layer is an energy absorbing layer configured to absorb a radial component of an impact.
Optionally, the first and/or second padded layer is a comfort padded layer.
According to a third aspect of the invention there is provided, protective apparel comprising the pad or padding of any preceding aspect.
Optionally, the pad or padding forms an interface layer of the apparel configured to interface with a wearer.
Optionally, the pad or padding forms an outer layer of the apparel configured to directly receive an impact.
Optionally, the apparel is substantially formed from the padding, such that one of the first support layer and the second support layer forms an interface layer of the apparel configured to interface with a wearer and the other of the first support layer and the second support layer forms an outer layer of the apparel configured to directly receive an impact.
Optionally, the apparel is headgear.
According to a fourth aspect of the invention helmet comprising: an outer shell; an energy absorbing layer arranged radially inward of the outer shell; and the pad or padding of any previous aspect provided on a radially inward facing surface of the energy absorbing layer.
According to a fifth aspect there is provided a helmet comprising: an outer shell; a head mount configured to mount the helmet on a wearer’s head, suspended radially inward of the outer shell with a gap there between; and the pad or padding of any previous aspect provided on radially inward facing surface of the head mount.
According to a sixth aspect there is provided soft headgear for contact field sports, such as rugby and/or soccer, comprising: an inner layer configured to accommodate a wearer’s head; an outer layer covering at least a part of the inner layer; wherein the headgear is substantially formed from the padding of the second aspect, such that one of the first support layer and the second support layer forms the inner layer of the headgear and the other of the first support layer and the second support layer forms the outer layer of the headgear.
The invention is described in detail below, with reference to the accompanying figures, in which:
Between the first and second support layers 101, 102 are provided first and second padded layers 103, 104. The padded layers 103, 104 may be formed from a gel material or a foam material for example. The properties of the gel material or foam material may be selected for a specific purpose, such as for energy absorbing or comfort. For energy absorbing, a relatively high density material might be chosen such as expanded polystyrene (EPS), expanded polypropylene (EPP), expanded polyurethane (EPU), or expanded ethylene-vinyl acetate (EVA). For comfort, a relatively low density material might be chosen such as latex, EVA and/or PVC foam, for example.
Energy absorbing materials are those designed to absorb the energy of an impact. Other components may absorb that energy to a limited extent, but that is not their primary purpose and their contribution to the energy absorption is minimal compared to the energy absorption of the energy absorbing material. Indeed, although 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 protective apparel 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.
The first and second padded layers 103, 104 in the pad 100 may be any combination of material types. For example, the may both be energy absorbing, both be comfort padding or one may be energy absorbing and the other comfort padding. For applications where the pad 100 may come into contact with a wearer, i.e. at an interface between the apparel and the wearer, at least one comfort padding layer may be preferable. More preferably this may be the padded layer closest to the wearer.
The padded layers 103, 104 are preferably relatively thin in the thickness dimension, compared to width or length. Accordingly, they may be sheet-like. Indeed they may be formed from a larger sheet of material. The shape of the padded layers 103, 104 is not particularly important. However, for symmetry, circular disks may be preferred. Squares or rectangles are also suitable, as are other shapes. Preferably, the padded layers 103, 104 are the same size and shape.
Between the first and second padded layers 103, 104 are provided first and second low friction layers 105, 106. The low friction layers 103, 104 may be fixed to or integrated with respective opposing surfaces of the first and second padded layers 103, 104. Alternatively, the low friction layers 103, 104 may be loose within the pad 100. Accordingly, a low friction interface is provided between the first and second low friction layers 105, 106 and, by extension, between the first and second padded layers 103, 104. Therefore, the first and second padded layers 103, 104 are able to slide relative each other. The sliding occurs in a plane substantially parallel to the padded layers 103, 104.
The low friction layers 103, 104 may be formed from a plastic, such as polycarbonate (PC), or a composite material. In some arrangements, it may be desirable to configure the low friction layers 105, 106 such that the coefficient of friction at the sliding interface is between 0.001 and 0.3 and/or below 0.15.
The sliding may in a relative movement between first and second padding layers 103, 104 in a range of between 1 mm and 100 mm, optionally greater than 5 mm, 10 mm, or 15 mm, optionally less than 15 mm, 20 mm or 30 mm.
The above described sliding between the first and second padded layers 103, 104 is further facilitated by the second support surface 102, which is configured to stretch to accommodate the sliding. Accordingly, the second support 102 surface may be formed from a stretchable material, such as a stretchable fabric, like Lycra™.
The first support layer 101 may also be formed from a stretchable material, however, this is not necessary. In some embodiments, the first support layer 101 may be formed from a fabric material that forms part of a hook-and-loop (Velcro™) fastening means. For example, the first support layer 101 may be formed from brushed nylon (soft Velcro™). This arrangement means that the first support layer 101 and the pad 100 as a whole can easily be attached to an item of protective apparel. In alternative embodiments, alternative fastening means may be used, that are attached to the first support layer, such as poppers, magnets, glue or tape.
In some embodiments, the first and second support layers 101, 102 may, for example, be formed from a textile, a cloth and/or a fabric. These may be constructed from synthetic yarns, such as Polyester (PES), Polyamide (PA, e.g. PA6) and/or Elastane, natural yarns, such as cotton and/or wool, or a combination of both. However, other materials may also be used, including felts and directly-formed flexible sheet materials including, for example, leather and/or artificial leather. Preferably, the inner and outer layers are made from soft, thin materials so as not to cause injury to wearers.
It should be appreciated that the first and second support layers 101, 102 may be formed from different materials and/or different types of material. The layer of material to be provided on the inside of the headgear may be selected for one particular quality, such as comfort for the wearer, while a second material may be selected for the other layer, for example for wear resistance. Alternatively, both layers may be formed from the same material.
The first and second support layers 101, 102 may be connected to each other by heat welding, stitching or other means.
Although not shown in the figures, further padded layers and corresponding low friction layers may be provided. For example rather than two padded layers with one sliding interface between them, there may be N padded layers, with N-1 sliding interfaces (where N is an integer greater than two). Three padded layers may be particularly advantageous for some applications. For example, with three padded layers, an energy absorbing padded layer can be arranged between two comfort padding padded layers.
The distinct pads 100 forming the padding 200 may vary in size and/or shape from one another, and/or in the padding materials and/or low friction materials used. However, preferably the distinct pads 100 forming the padding 200 share a common first support layer 101 and/or a common second support layer 102. Preferably still, the common support layers are connected to each other between the pads 100, e.g. at least around the perimeter of the pads and possibly also in the space between.
Below are described a number of examples of protective helmets to which the pads 100 or padding 200 may be applied. Multiple pads 100 may be used and/or multiple sections of padding 200. The proportions of the thicknesses of the various layers 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.
The helmet 1 shown in
The outer shell 2 is preferably relatively thin (e.g. compared to the energy absorbing layer 3) 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.
Although not shown, the helmet 1 may further comprise a head mount located radially inward of the energy absorbing layer 3. Pads 100 or padding 200 may be attached to an inward facing surface of the energy absorbing layer 3 or head mount that would otherwise contact the wearer’s head. Providing the above described pads 100 or padding 200 to this type of helmet improves the protection provided by the helmet against oblique impacts without compromising comfort. Further the pads 100 or padding 200 may be retrofitted to existing helmets.
Arranged between the outer shell 2 and the energy absorbing layer 3, at the sliding interface 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, the sliding layer 4 may be configured such that sliding occurs between the two parts during an impact. For example, the sliding layer 4 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.
The helmet 1 shown in
The sliding layer 4 can be provided in many different ways. 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 can be seen, the force K gives rise to a displacement 12 of the outer shell 2 relative to the energy absorbing layer 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 energy absorbing layer 3 and the outer shell 2.
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 energy absorbing layer 3 (i.e. during an impact the outer shell 2 can be rotated by a circumferential angle relative to energy absorbing layer 3).
A few possible variants of the helmet shown in
Pads 100 or padding 200 may be attached to an inward facing surface of the energy absorbing layer 3 or head mount, that would otherwise contact the wearer’s head. Providing the above described pads 100 or padding 200 to this type of helmet further improves the protection provided by the helmet against oblique impacts without compromising comfort. Further, the sliding function can be shared between different structures of the helmet, thus lowering the engineering burden on each structure or providing redundancy. The pads 100 or padding 200 may be retrofitted to existing helmets.
The head mount 13 may be provided in any form that may conform to the head of a wearer and mount 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. In some arrangements, the head mount 20 may include a head band 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. The head mounts mentioned earlier in the context of other helmets may be the same as described here.
A sliding facilitator 4 is provided radially inwards of the energy absorbing layer 3, at the sliding interface. The sliding facilitator 4 is provided to assist sliding of the energy absorbing layer 3 in relation to an head mount 13, in the same manner as discussed above in relation to the second example helmet. 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
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 head mount 13.
Multiple sliding facilitators 4 may be provided, e.g. 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 head mount 13 can be fixed to the energy absorbing layer 3 and/ or the outer shell 2 by means of connectors 5, such as the four connectors 5a, 5b, 5c and 5d in
Pads 100 or padding 200 may be attached to an inward facing surface of the head mount 13 that would otherwise contact the wearer’s head. Providing the above described pads 100 or padding 200 to this type of helmet further improves the protection provided by the helmet against oblique impacts without compromising comfort. Further, the sliding function can be shared between different structures of the helmet, thus lowering the engineering burden on each structure or providing redundancy. The pads 100 or padding 200 may be retrofitted to existing helmets.
In a helmet such as that depicted in
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 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. 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.
As shown in
In an arrangement, the connectors 25 may be configured to be relatively elastic, namely to have a lower modulus of elasticity than the outer shell 2 and/or the head mount 20. For the avoidance of doubt, references to the modulus of elasticity of a component refers to the ratio of the force exerted on the component to the extension induced by the force within a given range of extension. It should be appreciated that, for a component formed from multiple elements, this may differ from the modulus of elasticity for the bulk material from which it is formed.
By connecting the head mount 20 to the outer shell 2 using relatively elastic connectors 25, the outer shell 2 may rotate relative to the head mount 20 in response to an impact, providing corresponding benefits in respect of managing impact energies that were discussed above. Depending on the intended use of the helmet and the configuration of the helmet and the connectors 25, the outer shell 2 may be able to rotate relative to the head mount 20 about different axes, such as an axis extending generally from the front to the back of the head of the wearer, an axis extending generally from side to side of the head of the wearer and an axis extending generally parallel to the spine of the wearer. Appropriate design of the helmet and the connectors 25 enables control of rotation of the outer shell 2 relative to the head mount 20 about the different axes in response to different impacts.
Pads 100 or padding 200 may be attached to an inward facing surface of the head mount 13 that would otherwise contact the wearer’s head. Providing the above described pads 100 or padding 200 to this type of helmet further improves the protection provided by the helmet against oblique impacts without compromising comfort. Further, the sliding function can be shared between different structures of the helmet, thus lowering the engineering burden on each structure or providing redundancy. The pads 100 or padding 200 may be retrofitted to existing helmets.
In contrast to the above described examples, the pads 100 or padding 200 may form an outer layer (i.e. with respect to the wearer) of the apparel configured to directly receive an impact. For example, the pads 100 or padding 200 may be attached to the outer surface of the outer shell, or energy absorbing layer, of any of the example helmets described above. In a specific example, a single layer of padding 200 (appropriately shaped) may be configured to cover the entire outer shell 2.
In another specific example shown in
The apparel shown in
The headgear 40 is substantially formed from padding 200 such that the first support layer 101 forms an inner layer configured to accommodate a wearer’s head. Accordingly, the inner layer defines a cavity within which a head can be inserted. The second support layer 102 forms an outer layer of the headgear 40. The padded layers 103, 103, and low friction layers 104, 105 are configured to absorb and/or redirect energy of an impact between the headgear and an object.
The pads 100 of the padding 200 may be configured to cover the top and/or sides of the wearer’s head. Preferably, the padded layers 103, 104 are made from soft, thin materials so as not to cause injury to players.
In the above example headgear 40, it may be preferable that the padding layers facing towards the wearer has the same texture, hardness and/or density as the padding facing away from the wearer. This may ensure that the forces experiences by the wearer and an opponent are similar.
In the above example headgear 40, it may be preferable that the padded layer has a maximum uncompressed thickness of no more than 1 cm, and/or has a maximum density of no more than 60 kilograms per cubic meter, or optionally no more than 45 kilograms per cubic meter.
Alternatively, the headgear 40 may be provided in the form of a headband configured to encircle the wearer’s head. The headband may be configured to at least cover the forehead of the wearer. The ears may also be covered.
Variations of the above described embodiments 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.
Number | Date | Country | Kind |
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2009991.7 | Jun 2020 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/067836 | 6/29/2021 | WO |