Impact absorbing structure

Abstract

The helmet includes an impact mitigation structure (100) that includes a first inner layer (102), a second outer layer (104), and a reactive layer (105) disposed between the first inner layer and the second outer layer. The reactive layer includes a plurality of elements (106) that are held between the first inner layer and the second outer layer. The reactive layer is disposed such that the plurality of elements are configured to roll to facilitate movement of the first inner layer and the second outer layer relative to one another when the second layer is impacted.

Description

[Technical Field]

[0001] The present invention relates to a shock absorbing structure, and more particularly to a shock absorbing structure having multiple layers. [Background technology]

[0002] If a person or object experiences a sufficiently large impact, injury to the person or damage to the object can occur. Significant development effort has been expended to produce impact mitigating structures, particularly helmets and body armor, that provide protection from damaging or potentially injurious impacts.

[0003] Head injuries, which can be sustained from participating in sports such as bicycling, horseback riding, or rock climbing, are a common cause of serious brain damage. Brain injuries can occur as a result of either a localized impact to the head, a sudden acceleration or deceleration within the skull, or a combination of both impact and movement. Impact protection is therefore important in preventing brain damage from head impacts.

[0004] Head protection in the form of a helmet is designed to reduce the forces exerted on a user's head during an impact. Helmets generally include at least one impact-absorbing layer designed to absorb some of the forces exerted on the helmet during an impact. Body armor similarly provides protection for other parts of the body. Summary of the Invention [Problem to be solved by the invention]

[0005] However, helmets and body armor often do not provide adequate protection against both linear and tangential forces during impact. Because oblique impacts are common, impacts often contain both linear and tangential components. Tangential forces, in particular, result in rotational acceleration of the brain, which is associated with rupture of bridging veins. This can then lead to subdural hematomas and diffuse axonal injury. Tangential forces during impact can also cause cervical spine injuries. [Means for solving the problem]

[0006] SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved shock absorbing structure. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a shock-absorbing structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 6A] FIG. 6A is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 6B] FIG. 6B is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram showing a shock-absorbing structure according to one embodiment of the present invention. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 9] FIG. 9 is a schematic diagram showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 11] FIG. 11 is a diagram illustrating the movement of various components of a shock mitigating structure according to one embodiment of the present invention. [Figure 12] FIG. 12 is a diagram illustrating the movement of various components of a shock mitigating structure according to another embodiment of the present invention. [Figure 13] FIG. 13 is a schematic diagram showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 14] 14, 15 and 16 show schematic diagrams of how reactive layer connections may be arranged according to embodiments of the present invention. [Figure 15] 14, 15 and 16 show schematic diagrams of how reactive layer connections may be arranged according to embodiments of the present invention. [Figure 16] 14, 15 and 16 show schematic diagrams of how reactive layer connections may be arranged according to embodiments of the present invention. [Figure 17] FIG. 17 is a schematic diagram showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 18] 18, 19 and 20 show schematic diagrams of how the cylindrical elements of the reaction layer may be arranged according to embodiments of the present invention. [Figure 19] 18, 19 and 20 show schematic diagrams of how the cylindrical elements of the reaction layer may be arranged according to embodiments of the present invention. [Figure 20] 18, 19 and 20 show schematic diagrams of how the cylindrical elements of the reaction layer may be arranged according to embodiments of the present invention. [Figure 21] FIG. 21 is a schematic diagram showing a shock absorbing structure according to another embodiment of the present invention. [Figure 22] FIG. 22 is a schematic cross-sectional view showing a shock absorbing structure according to another embodiment of the present invention. [Figure 23] FIG. 23 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 24AB] 24A and 24B are schematic cross-sectional views showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 25] FIG. 25 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 26] FIG. 26 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 27]FIG. 27 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 28] FIG. 28 is a schematic cross-sectional view showing a shock absorbing structure according to another embodiment of the present invention. [Figure 29] FIG. 29 is a schematic cross-sectional view showing a shock absorbing structure according to another embodiment of the present invention. [Figure 30AB] 30A and 30B are schematic diagrams showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 31] FIG. 31 is a schematic cross-sectional view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 32AB] 32A and 32B are schematic cross-sectional views showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 33AB] 33A and 33B are schematic cross-sectional views showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 34] FIG. 34 is a schematic cross-sectional view showing a shock absorbing structure according to another embodiment of the present invention. [Figure 35AB] 35A and 35B are schematic cross-sectional views showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 36] FIG. 36 is a schematic exploded view showing a shock-absorbing structure according to another embodiment of the present invention. [Figure 37] FIG. 37 is a schematic exploded view showing a shock absorbing structure according to another embodiment of the present invention. [Figure 38] 38 and 39 are schematic diagrams showing a helmet formed from an impact mitigation structure according to one embodiment of the present invention. [Figure 39] 38 and 39 are schematic diagrams showing a helmet formed from an impact mitigation structure according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Viewed from a first aspect, the present invention provides a helmet comprising an impact mitigation structure, the impact mitigation structure comprising: First inner layer; a second outer layer; and a reactive layer disposed between the first inner layer and the second outer layer, the reactive layer comprising a plurality of elements held between the first inner layer and the second outer layer; Equipped with The reactive layer is arranged such that when the second layer is impacted, multiple elements of the reactive layer are configured to roll to promote movement of the first inner layer and the second outer layer relative to one another.

[0009] Thus, the present invention provides a helmet including an impact mitigation structure. The impact mitigation structure is formed from multiple layers (a reactive layer sandwiched between an inner (first) layer and an outer (second) layer), and the reactive layer promotes (facilitates) the movement of other (e.g., impact-absorbing) layers relative to one another. When the helmet, particularly the second (outer) layer of the impact mitigation structure, is subjected to an impact (e.g., above a threshold), at least a portion of the force from the impact is transmitted to the reactive layer. This causes rolling of multiple (e.g., discrete) elements. This rolling movement of the multiple elements of the reactive layer allows the second layer to move (e.g., slide or rotate) relative to the first (inner) layer and / or vice versa. Movement of these layers can occur during and after the impact.

[0010] Those skilled in the art will appreciate that the provision of a reaction layer within the impact mitigation structure facilitates movement of the first and second layers relative to one another due to the rolling of elements between the first and second layers, and helps transfer some of the energy from the impact to the movement of the layers relative to one another, which helps transfer energy from the impact (e.g., to the reaction layer) such that the amount of energy transferred to the head that the helmet is protecting is reduced.

[0011] The reactive layer serves to convert energy from an impact into linear and / or rotational movement of the layers relative to one another. In particular, the energy from the impact can be transferred to the reactive layer (e.g., multiple elements of the reactive layer) (e.g., converted into kinetic and / or potential energy of the reactive layer (e.g., multiple elements of the reactive layer)), thereby preventing the energy from being dissipated by the helmet layers and / or transmitted to layers of the helmet adjacent to the user's head. Thus, preferably, the reactive layer (e.g., multiple elements of the reactive layer) is configured to receive kinetic and / or potential energy (from the energy of the impact) when the impact mitigation structure is impacted. This serves to reduce linear and rotational forces transmitted through the impact mitigation structure, for example, to the body that the impact mitigation structure is intended to protect. As will be appreciated, for a helmet that protects the wearer's head, this serves to reduce the likelihood of head and brain injuries.

[0012] Transferring energy to the reactive layer (by mechanical work being done on the reactive layer) and / or isolating the inner layer from forces exerted on the outer layer upon impact is in contrast to conventional helmets that either dissipate energy within the helmet (e.g., between the helmet layers) via, for example, connector deformation or interlayer friction, or that do not isolate the inner layer, which often results in a significant amount of energy being transferred to the inner layer from the initial kinetic energy of the head and helmet upon impact.

[0013] Furthermore, in at least preferred embodiments, the arrangement of the reactive layers in which the elements are held in place may be configured to introduce (or set) a certain threshold at which the elements begin to tumble (e.g., become disorganized) and allow the layers to move relative to one another. This can be used to help provide a helmet with an impact mitigating structure that is particularly suited to its use, and to help increase the amount of energy transferred to the movement of the layers relative to one another.

[0014] Preferably, the first inner layer, second outer layer and / or reaction layer are configured such that, upon impact to the impact mitigating structure, a majority of the rotational energy of the impact (i.e. that portion of the energy of the impact that causes the layers of the helmet to rotate relative to one another) is transferred to the second outer layer and / or reaction layer. The transfer of energy to the second outer layer and / or reaction layer, rather than to the inner layer(s) of the helmet, is considered to be novel and inventive in itself, and therefore, viewed from a further aspect, the present invention provides a helmet comprising a impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; a third intermediate layer positioned between the first inner layer and the second outer layer; Equipped with The first inner layer, the second outer layer, and / or the third intermediate layer are configured so that when the impact mitigation structure is subjected to an impact, a majority of the rotational energy of the impact is transferred to the second outer layer and / or the third intermediate layer.

[0015] Thus, in this aspect of the invention, the incoming rotational kinetic energy of an impact (between the head and helmet) is transferred (e.g. absorbed) to a separate intermediate layer (e.g. a reaction layer) or second outer layer disposed between the inner and outer layers of the impact mitigation structure, but is not transferred (e.g. not absorbed) to other layers or components between the layers of the impact mitigation structure. Preferably, therefore, a small amount (e.g. substantially none) of the rotational energy of the impact is dissipated between any of said layers of the impact mitigation structure.

[0016] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0017] Preferably, the impact mitigation structure (e.g., the first inner layer, second outer layer, and / or reaction layer of the impact mitigation structure) is configured to substantially decouple and / or isolate (mechanically) the first inner layer from the second outer layer, which helps to prevent rotational energy from being transmitted between the outer and inner layers of the impact mitigation structure and helps to prevent rotational energy from an impact from being transmitted to the head of the helmet wearer.

[0018] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; a third intermediate layer positioned between the first inner layer and the second outer layer; Equipped with The first inner layer, the second outer layer, and / or the third intermediate layer are configured to substantially separate and / or isolate the first inner layer from the second outer layer.

[0019] This separates and / or isolates the inner layer from the other layers of the helmet, helping to prevent rotational impacts acting on the inner layer of the helmet (preferably a helmet configured to be worn on the head) and thus on the head.

[0020] Rather than dissipating rotational kinetic energy between the layers of the helmet (as in conventional helmets), the reactive layer gains kinetic and / or potential energy from the rotational energy of the impact. This can result, for example, in random and chaotic free motion of the elements of the reactive layer, e.g., in any direction and around any axis. This energy can be thought of in the same way as the internal energy possessed by molecules and particles.

[0021] It will be appreciated that the helmet and impact mitigating structure of this aspect of the invention may comprise any (e.g., all) of the optional and preferred features outlined herein with respect to any of the other aspects and embodiments of the invention. Preferably, the inner layer, outer layer, and / or third intermediate layer are substantially decoupled and / or isolated from one another such that when the impact mitigating structure is subjected to an impact (e.g., an impact having at least a particular force), one or more (e.g., all) of the first inner layer, second outer layer, and / or third intermediate layer are substantially free to move relative to one another.

[0022] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; a third intermediate layer positioned between the first inner layer and the second outer layer; Equipped with When the impact absorbing structure is subjected to an impact, the first inner layer, the second outer layer and / or the third intermediate layer are configured to move substantially freely relative to one another.

[0023] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0024] The first layer, second layer, and reactive layer, both individually and collectively, can have any suitable and desired geometric shape. Preferably, one or more (e.g., each) of the first layer, second layer, and reactive layer has a thickness less than their other two dimensions (e.g., across the surface area of ​​each layer). Preferably, one or both of the first layer and second layer has a thickness greater than the thickness of the reactive layer. As described below, this may depend on the nature and function of the first layer and / or second layer. Preferably, the thickness of one or more (e.g., each) of the first layer, second layer, and reactive layer is substantially constant.

[0025] In preferred embodiments, one or more (e.g., all) of the first layer, second layer, and reactive layer are disposed substantially parallel to one another. Thus, preferably, the reactive layer is sandwiched between the first and second layers such that the first, second, and reactive layers are stacked on top of one another. The reactive layer can extend over substantially the same surface area as the first and / or second layers, and preferably, one or both of the first and second layers extend over a larger surface area (e.g., perpendicular to their thickness) than the surface area over which the reactive layer extends. In some embodiments, the reactive layer extends over a surface area of ​​the helmet (the helmet's impact-mitigating structure) where any impact may occur.

[0026] In a preferred embodiment, one or more (e.g., each) of the first layer, second layer, and reactive layer are curved (e.g., doubly) (e.g., across the entire surface area of ​​each layer). Preferably, the shapes and curvatures of the first layer, second layer, and reactive layer are such that they are compatible with one another. Preferably, the first layer has a convex surface facing the reactive layer (and preferably has a concave surface facing away from the reactive layer, e.g., toward the user's head). Preferably, the second layer has a concave surface facing the reactive layer (and preferably has a convex surface facing away from the reactive layer, e.g., away from the user's head). Preferably, the reactive layer has a concave surface facing the first layer and a convex surface facing the second layer.

[0027] In one embodiment, the first layer comprises a single (e.g., continuous and / or integrally formed) layer. In one embodiment, the second layer comprises a single (e.g., continuous and / or integrally formed) layer. In one embodiment, the first layer comprises multiple (e.g., discrete) sections, segments, or portions that together form the first layer. In one embodiment, the second layer comprises multiple (e.g., discrete) sections, segments, or portions that together form the second layer.

[0028] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; Equipped with one or both of the first inner layer and the second outer layer comprises a plurality of discrete portions; The impact absorbing structure further comprises a reaction layer disposed between the first inner layer and the second outer layer; the reactive layer comprises a plurality of elements held between the first inner layer and the second outer layer; and The reactive layer is arranged such that when the second layer is impacted, the plurality of elements of the reactive layer are configured to roll to promote movement of at least one of the plurality of discrete portions relative to another of the plurality of discrete portions.

[0029] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0030] The reactive layer can be disposed in any suitable and desired manner between a first inner layer (e.g., one or more portions of the inner layer) and a second outer layer (e.g., one or more portions of the outer layer). In one embodiment, the reactive layer comprises multiple (e.g., discrete) sites, sections, or portions that together form the reactive layer. For example, multiple elements of the reactive layer may be distributed in separate regions to provide multiple (e.g., discrete) sites, sections, or portions that together form the reactive layer. Thus, there may be one or more regions (e.g., sites, sections, or portions) between the first and second layers (e.g., between multiple (e.g., discrete) sites, sections, or portions of the reactive layer) where no reactive element is present.

[0031] When two or more of the first layer, second layer, and reactive layer include a plurality of (e.g., discrete) sites, sections, or portions that together form the respective layer, the plurality of (e.g., discrete) sites, sections, or portions in each layer may correspond (e.g., match) to one another. Thus, the arrangement (e.g., shape and / or size) of the plurality of (e.g., discrete) sites, sections, or portions in two or more of the first layer, second layer, and reactive layer may correspond (e.g., match and / or be the same) to one another.

[0032] When the first layer and / or the second layer (and, for example, the reaction layer) comprises a plurality of (e.g., discrete) sites, sections, or portions, preferably, the plurality of (e.g., discrete) sites, sections, or portions of the first layer and / or the second layer are configured to roll when one or more of the plurality of (e.g., discrete) sites, sections, or portions of the second layer are impacted, to promote movement of one or more of the plurality of (e.g., discrete) sites, sections, or portions of the first layer and / or the second layer relative to one another.

[0033] Thus, for example, one or more of the plurality of (e.g., discrete) regions, sections, or portions of the second layer may be arranged to move (e.g., independently) relative to other(s) of the plurality of (e.g., discrete) regions, sections, or portions of the second layer and / or to move (e.g., independently) relative to (e.g., multiple (e.g., discrete) regions, sections, or portions) of the first layer. Similarly, one or more of the plurality of (e.g., discrete) regions, sections, or portions of the first layer may be arranged to move (e.g., independently) relative to other(s) of the plurality of (e.g., discrete) regions, sections, or portions of the first layer and / or to move (e.g., independently) relative to (e.g., multiple (e.g., discrete) regions, sections, or portions) of the second layer.

[0034] The shock mitigating structure may comprise any suitable and desired number of reactive layers (and other layers). In one set of embodiments, the shock mitigating structure comprises at least two reactive layers. Preferably, the shock mitigating structure comprises additional layers. For example, a first reactive layer may be located between the first (inner) layer and the third (intermediate) layer, and a second reactive layer may be located between the third (or fourth intermediate) layer and the second layer. The additional layers may also comprise one or more low-friction layers as described herein, for example, disposed between other layers of the shock mitigating structure. There may be multiple layers between or around each reactive layer and / or low-friction layer.

[0035] The additional reactive layer(s) can be arranged in any suitable and desired configuration, for example, in substantially the same (e.g., identical) configuration as the first reactive layer. The additional (intermediate) layers can be arranged in any suitable and desired configuration, for example, in substantially the same (e.g., identical) configuration as the first and / or second layer.

[0036] The shock mitigating structure can include any suitable and desirable number of elements. In some embodiments, the number of elements in the plurality of elements is between 5 and 100,000, e.g., between 50 and 10,000, e.g., between 100 and 1,000. In one set of embodiments, the number of elements can be proportional to the size (e.g., surface area) of the shock mitigating structure (of one or more layers). For example, larger shock mitigating structures can include more elements. In one set of embodiments, the ratio of the surface area of ​​the reactive layer on which the elements are provided to the surface area of ​​the reactive layer is between 0.05 and 0.5, e.g., between 0.1 and 0.4, e.g., about 0.25.

[0037] In one set of embodiments, the ratio of the volume of the reactive layer occupied by the elements to the (total) volume of the reactive layer (i.e., the relative density of the elements) is between 0.15 and 0.6, such as between 0.2 and 0.5, such as between 0.3 and 0.4. This helps to control the amount of rotation imparted to the wearer's head through the helmet so that back rotation of the wearer's head is reduced (e.g., minimized), and preferably helps to reduce (e.g., minimize) rotational forces imparted to the wearer's head and brain as a result of an impact.

[0038] Therefore, preferably, the relative density of the sizes of the elements in the reactive layer is configured to reduce (eg, minimize) rotational forces transmitted to the wearer's head and brain as a result of an impact.

[0039] The plurality of elements may be formed from any suitable and desirable elements that facilitate movement of one layer of the impact mitigation structure relative to another. Individual elements of the plurality of elements may vary in configuration (e.g., shape, size) among themselves, or in some embodiments, the plurality of elements are substantially identical to one another. This may help improve consistency of behavior of the reaction layers throughout the impact mitigation structure.

[0040] Each element of the plurality of elements comprises a polyhedron (e.g., having (only) straight sides and flat faces). Preferably, the element is at least partially rounded, e.g., at least half of the surface area of ​​the element is rounded. Thus, in some embodiments, the element does not comprise any straight sides or flat faces. Rounded elements may be more easily rotated (e.g., rotated relative to the first and / or second layers) to facilitate movement of the first and / or second layers.

[0041] In some embodiments, the elements are (substantially) spheroidal, e.g., spherical. Spheroidal elements can rotate (e.g., roll) in multiple (e.g., any) directions, which helps to improve the motion of the first and / or second layers upon impact (e.g., independent of the direction of impact) and thus more effectively reduce force transfer through the impact mitigation structure. Such an effect can even be observed with elements having at least partially rounded surface areas.

[0042] In one embodiment, one or more (e.g., all) of the plurality of elements (e.g., each) have a dimension in one direction that is greater than a dimension in another (e.g., perpendicular) direction. Thus, for example, one or more (e.g., each) of the plurality of elements has a minimum dimension that is less than the maximum dimension of each element. The plurality of elements can be shaped in any suitable and desired manner to impart this (e.g., non-spherical) shape.

[0043] In one embodiment, one or more (eg all) of the plurality of elements are (substantially) prismatic, eg cylindrical (preferably cylindrical with a (substantially) circular cross section).

[0044] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and a plurality of cylindrical elements held between said first inner layer and said second outer layer; Equipped with The plurality of cylindrical elements are arranged such that when the second layer is impacted, the plurality of cylindrical elements are configured to roll in a direction perpendicular to their respective axes to promote movement of the first inner layer and the second outer layer relative to one another.

[0045] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may include any (e.g. all) of the optional and preferred features outlined herein with respect to any of the other aspects and embodiments of the invention. Thus, for example, the plurality of cylindrical elements form part of a reaction layer between the first inner layer and the second outer layer when the second layer is impacted.

[0046] Preferably, the dimension of the prismatic body (e.g., cylinder) along its axis (principal axis, projection axis) is greater than the dimension of the prismatic body (e.g., cylinder) perpendicular to its axis (principal axis, projection axis). Thus, for example, if the plurality of elements comprises a plurality of cylinders, the length of the cylinder along the axis of symmetry is greater than the diameter of a circle (perpendicular to the axis) forming a cross section of the cylinder. Like the plurality of elements in general, the plurality of cylinders can have a plurality of different sizes and shapes (e.g., ratios of length to diameter). Similarly, like the plurality of elements in general, the plurality of cylinders may comprise a low-friction material. The cylinders may be formed from a low-friction material or may comprise a low-friction coating.

[0047] When the elements have one dimension that is larger than another (e.g., perpendicular) dimension, the elements are preferably arranged (e.g., distributed and / or positioned) in the reaction layer such that their larger dimensions are not aligned with one another (e.g., not all of them). Thus, for example, when the elements comprise a plurality of cylindrical bodies, the axes of symmetry of the cylindrical bodies are preferably not aligned with one another (e.g., not all of them). To promote movement of the first inner layer and the second outer layer relative to one another, the non-alignment of the elements such that the elements roll in different directions when the second layer is impacted helps to control the amount and / or direction of rolling of the elements, which in turn helps to control the amount and / or direction of friction between the first layer and the second layer.

[0048] The elements of the plurality of elements can have any suitable and desired size. Applicant understands that the size of the elements can be selected depending on the intended use of the impact mitigation structure (e.g., helmet, armor). In some embodiments, the elements (each) have a maximum size (e.g., diameter) of 0.1 mm to 4 mm, e.g., 0.5 mm to 3 mm, e.g., 1 mm to 2 mm. Preferably, the elements (each) have a (maximum) size greater than one-quarter (e.g., greater than one-half) the thickness of the reaction layer, e.g., greater than one-quarter (e.g., greater than one-half) the thickness between the separation between the first and second layers.

[0049] In some embodiments, each of the plurality of elements has substantially the same shape, size, and / or dimensions. In some embodiments, the plurality of elements has a plurality of different shapes, sizes, and / or dimensions. For example, the plurality of elements may include a plurality of larger elements (having one particular size) and a plurality of smaller elements (having a different, smaller particular size).

[0050] The size, and e.g., relative density, of the elements are preferably configured to reduce (e.g., minimize) rotational forces transmitted to the wearer's head and brain as a result of an impact, e.g., to reduce (e.g., minimize) counter-rotation of the wearer's head.

[0051] The first layer and the second layer can be spaced apart from each other by any suitable and desired distance. In one embodiment, the spacing between the first layer and the second layer (e.g., at least in the region where the reactive layer is provided) is substantially constant. In this embodiment, the spacing between the first layer and the second layer (e.g., at least in the region where the reactive layer is provided) is variable. Thus, for example, there may be regions where the spacing between the first layer and the second layer in one region is smaller than the spacing between the first layer and the second layer in a different region.

[0052] If the spacing between the first and second layers is variable, the size of the elements is preferably variable (e.g., to match the spacing between the first and second layers). Thus, for example, the elements may be smaller in a first region where the spacing between the first and second layers is smaller, and the elements may be larger (compared to the size of the elements in the first layer) in a second region where the spacing between the first and second layers is larger (compared to the spacing in the first region).

[0053] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; Equipped with the first inner layer is spaced from the second outer layer by a first distance across a first region between the first inner layer and the second outer layer; the first inner layer is spaced from the second outer layer by a second distance across a second region between the first inner layer and the second outer layer; the first spacing is greater than the second spacing; and the impact mitigating structure comprising a plurality of rollable elements held between the first inner layer and the second outer layer; the plurality of rollable elements includes a first plurality of rollable elements disposed across the first region between the first inner layer and the second outer layer; the plurality of rollable elements includes a second plurality of rollable elements disposed across a second region between the first inner layer and the second outer layer; and The first plurality of rollable elements are larger than the second plurality of rollable elements.

[0054] It will be appreciated that the helmets and impact mitigation structures of this aspect of the invention may include any (e.g., all) of the optional and preferred features outlined herein with respect to any of the other aspects and embodiments of the invention. Thus, preferably, when the second layer is impacted, the plurality of elements (e.g., forming part of the reactive layer) are arranged so as to be configured to roll to promote movement of the first inner layer and the second outer layer relative to one another. Preferably, the first plurality of rollable elements have a larger maximum dimension (e.g., diameter) than the second plurality of rollable elements. Preferably, the first plurality of rollable elements have a larger minimum dimension than the second plurality of rollable elements.

[0055] The element can be formed from any suitable and desirable material. The element may comprise a substantially incompressible fluid. The element may comprise a non-Newtonian fluid. Preferably, the element is substantially (e.g., entirely) solid (i.e., the element is incompressible and has a fixed shape). For example, the element may be formed from a material having a Shore A hardness of greater than 50, e.g., greater than 100. A material with this hardness does not easily compress or deform. Using a substantially incompressible (i.e., solid) element helps improve the rolling (e.g., rotation) of the element upon impact and improves the movement of the first and second layers relative to one another.

[0056] Preferably, the elements are rigid, for example having a Young's modulus greater than 0.1 GPa, such as greater than 1 GPa, for example greater than 10 GPa.

[0057] In one set of embodiments, the elements comprise a low-friction material. The elements may be formed from a low-friction material or may comprise a low-friction coating. Any suitable and desirable low-friction material and / or coating can be used. In one set of embodiments, the coefficient of friction is less than 0.6, e.g., less than 0.4, e.g., less than 0.2, e.g., less than 0.1, e.g., less than about 0.05. In some embodiments, the low-friction material and / or coating comprises nylon. The low-friction material can improve the rolling (e.g., rotation) of the elements (e.g., relative to each other and / or relative to the first and second layers) during and / or after impact with the impact-absorbing structure by allowing the elements to roll (e.g., rotate) more smoothly during and / or after impact. This can facilitate increased and / or smoother movement of the first and second layers relative to each other during and / or after impact.

[0058] In one set of embodiments, one or more (e.g., all) of the plurality of elements, the first layer, and the second layer comprise a high-friction material and / or coating, which can help promote torque between the plurality of elements and the first layer and / or the second layer when the impact mitigating structure is impacted and the plurality of elements contact the first layer and / or the second layer. This torque (e.g., overcoming the resistance to rolling) helps the plurality of elements to roll (e.g., rather than slip and slide relative to the first and / or second layer) to promote movement of the first and second layers relative to one another.

[0059] Thus, for example, instead of providing a low friction layer between the first and second layers to facilitate movement of the layers relative to one another, the applicant has appreciated that the movement of the first and second layers relative to one another is greatly improved by the rolling of multiple elements, which rolling of the multiple elements is itself facilitated by friction between the multiple elements and the first and / or second layers.

[0060] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and a plurality of elements held between the first inner layer and the second outer layer; Equipped with One or more of the elements, first inner layer, and second outer layer comprise a high friction material and / or coating such that the elements are configured to contact one or both of the first inner layer and the second outer layer when the impact mitigation structure is impacted, whereby the high friction material causes the elements to roll to facilitate movement of the first inner layer and the second outer layer relative to one another.

[0061] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention, and thus preferably the plurality of elements form at least part of the reactive layer.

[0062] In a preferred embodiment, the elements are held directly against (e.g., in contact with) the first layer and / or the second layer, preferably without an intermediate layer or interface (e.g., a low-friction layer and / or a retaining structure (e.g., a flexible layer)) between them. This utilizes friction between the elements and the first and / or second layer to help initiate the rolling of the elements on the first and / or second layer. Preferably, the first and / or second layer with which the elements come into contact comprises a hard layer (e.g., a layer harder than the shock-absorbing layer of the shock-mitigating structure, if provided).

[0063] In one set of embodiments, one or more (e.g., all) of the plurality of elements, the first layer, and the second layer comprise a textured or structured surface. The textured or structured surface of the plurality of elements may be complementary to the textured or structured surface of the first layer and / or the second layer that contact each other when the shock mitigating structure is impacted. For example, one or more (e.g., all) of the plurality of elements, the first layer, and the second layer may comprise racks and pinions, gears, interconnecting elements, ratchets, and spindles configured to engage with each other when the shock mitigating structure is impacted. Again, this helps to facilitate torque between the plurality of elements and the first layer and / or the second layer when the shock mitigating structure is impacted.

[0064] In one set of embodiments, the hardness of the elements is greater than the hardness of the first layer and / or the second layer. However, as outlined below, the first and / or second layers may comprise harder coatings (or additional hard layers) to interface with the elements. The hardness of the elements relative to the first and / or second layers helps to improve rolling (e.g., rotation) of the elements (e.g., relative to each other and / or relative to the first and / or second layers) during and / or after impact with the impact mitigating structure by reducing (e.g., substantially eliminating) deformation of the elements upon impact.

[0065] The elements may have different shapes, sizes, and / or be made from different materials, but preferably the elements are substantially identical in one or more (e.g., all) of their shapes, sizes, and materials.

[0066] The elements may be held between the first and second layers in any suitable and desired manner. Preferably, the reactive layer is configured such that when the second layer (or, for example, the reactive layer) is impacted, the elements of the reactive layer translate (displace) to facilitate movement of the first inner and second outer layers relative to one another, e.g., in addition to being configured to roll when the elements are impacted.

[0067] In a preferred embodiment, the elements of the reactive layer are held in a particular (e.g., fixed) arrangement (e.g., array) between the first and second layers, such that the elements are held (e.g., fixed) in the particular arrangement during normal use of the helmet, but then upon impact the particular arrangement is disturbed (and, e.g., released from) allowing the elements to roll and the first and second layers to move relative to one another.

[0068] Preferably, the elements are configured to be released (e.g., from a specific arrangement) when the shock mitigating structure is subjected to an impact. Preferably, the elements are configured to roll after being released. Thus, in this manner, the elements of the reactive layer are configured to "react" to an impact, for example, by providing a low-friction interface between the first layer and the second layer (i.e., the reactive layer after the elements are released), thereby facilitating movement (e.g., sliding) of (at least a portion of) the first inner layer and (at least a portion of) the second outer layer relative to each other.

[0069] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and a plurality of elements held between the first inner layer and the second outer layer; Equipped with the plurality of elements being held in a specific arrangement between the first inner layer and the second outer layer; the plurality of elements are maintained in the specified configuration when the impact mitigation structure is subjected to an impact below a specified threshold force; when the impact absorbing structure is subjected to an impact exceeding a certain threshold force, at least some of the elements are released from the certain arrangement; and The released element is configured to facilitate movement of the first inner layer and the second outer layer relative to one another.

[0070] It will be appreciated that the helmet and impact mitigating structure of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention. Preferably, therefore, the plurality of elements form at least a portion of the reaction layer. Preferably, the impact force calculated for a particular (threshold) force is a tangential component of the impact force, e.g., one that causes the layers of the helmet to rotate relative to each other. Preferably, therefore, the particular (e.g., threshold) force is a tangential component of a force (e.g., relative to a (e.g., layer) of the impact mitigating structure) that has a particular (e.g., threshold) tangent value. This force component may cause the helmet, and therefore the wearer's head, to rotate.

[0071] Preferably, the particular arrangement of the elements of the reactive layer is configured to be disturbed (e.g., the elements are capable of rolling) when the second layer is impacted in order to promote movement of the first inner layer and the second outer layer relative to one another.

[0072] In one set of embodiments, the reactive layer is arranged such that the elements are (e.g., released) to roll (allowing the first and second layers to move relative to one another) when the shock mitigating structure (e.g., the second layer of the shock mitigating structure) is subjected to an impact with at least a certain (e.g., predetermined, threshold) force (e.g., an oblique force). Preferably, the reactive layer is therefore arranged such that the particular arrangement of the elements is (e.g., released and) disturbed when the shock mitigating structure (e.g., the second layer of the shock mitigating structure) is subjected to an impact with at least a certain (e.g., predetermined, threshold) force (e.g., an oblique force). Preferably, the reactive layer is therefore configured to hold the elements in a predetermined position (e.g., fixed or in a particular arrangement relative to the first and / or second layer) until the shock mitigating structure is subjected to an impact with at least a certain (e.g., predetermined, threshold) force (e.g., an oblique force). This serves to keep the elements together (e.g., in a particular arrangement) during normal use, and to cause them to roll (e.g., the particular arrangement is disturbed) when subjected to a (e.g., sufficiently large) impact (i.e., an impact above a particular (e.g., tangential) force).

[0073] In some embodiments, the elements are arranged to be displaced (e.g., released and) displaced from their retained locations when the shock mitigating structure (e.g., the second layer of the shock mitigating structure) is impacted, e.g., when the elements disrupt (e.g., are released from) the specified configuration. For example, the elements can be free to move, e.g., roll, from their (previously) fixed positions. In one set of embodiments, the elements are arranged to roll when the specified configuration is disrupted. For example, the elements may be arranged to roll (e.g., rotate) in their fixed positions (within the reactive layer) when the second layer is impacted.

[0074] Preferably, the reactive layer is configured such that the elements are substantially unconstrained and free to move when the shock mitigating structure is subjected to an impact (e.g., an impact having at least a particular force). Preferably, the elements are configured to undergo substantially random and chaotic free movement, e.g., in any orientation and about any axis, when they are disturbed. Preferably, the reactive layer is configured such that the elements are free to move in three dimensions when they are disturbed (e.g., released by an impact). Preferably, the reactive layer (e.g., the elements of the reactive layer) is configured to substantially prevent geometric locking relative to the inner layer and / or outer layer when the shock mitigating structure is disturbed.

[0075] Preferably, the reactive layer (e.g., a plurality of elements of the reactive layer) is configured such that when the shock mitigation structure is subjected to an impact (e.g., an impact having at least a specified force), the plurality of elements are resistant to shock within 200ms. -1 Maximum speed of 80ms -1 Preferably, the reactive layer (e.g., the plurality of elements of the reactive layer) is configured such that when the shock mitigating structure is subjected to an impact (e.g., an impact having at least a particular force), the plurality of elements have a substantially constant resistance to rolling that is substantially independent of their velocity.

[0076] The specific force required to disrupt the elements can be selected to have any suitable and desired value (e.g., a value that causes the first and second layers to move relative to one another as a result of a sufficiently large impact). In one embodiment, the specific (e.g., predetermined, threshold) force is between 10 N and 100 N, such as between 30 N and 70 N, e.g., approximately 50 N. The specific force can be selected, for example, to reflect the lowest range of forces acting on the impact mitigation structure that could cause damage (e.g., injury) to the body protected by the impact mitigation structure, or to reflect the maximum force that a user protected by the helmet could exert on the impact mitigation structure (e.g., during normal use other than impact). This relatively low specific force helps reduce the amount of energy transferred from an impact to the impact mitigation structure, initiating activation of the reactive layer and thereby reducing energy transferred to the user.

[0077] The elements can be held in any desired and suitable arrangement. Preferably, the particular arrangement includes a fixed (e.g., spatial) arrangement of the elements. For example, the elements may be held in this fixed arrangement (e.g., such that the elements have defined positions relative to one another) until the elements are disturbed by an impact. In one embodiment, the particular arrangement comprises a (e.g., regular) array. Thus, the elements may be uniformly distributed (e.g., spaced apart) within (e.g., across) the reaction layer. For example, the elements may be distributed (e.g., spaced apart) according to a geometric distribution (pattern). However, other patterns and separations of the elements are also envisioned.

[0078] The fixed (e.g., spatial) arrangement of the elements, as well as, for example, their size and / or (relative) density, are preferably configured to reduce (e.g., minimize) rotational forces imparted to the wearer's head and brain as a result of an impact, for example, to reduce (e.g., minimize) counter-rotation of the wearer's head.

[0079] The particular arrangement in which the multiple elements are held in the reactive layer may be such that the reactive layer comprises multiple layers (e.g., individual layers) of the multiple elements. Preferably, the multiple layers of elements are arranged to lie substantially parallel to one another, e.g., extending substantially perpendicular to the thickness of the reactive layer. Preferably, the multiple layers of elements overlap one another (e.g., over a majority, e.g., substantially the entire, surface area of ​​the layer). In one embodiment, the reactive layer comprises only a single layer of the multiple elements.

[0080] The plurality of elements can be held (e.g., in a particular arrangement) between the first and second layers by any suitable and desired retaining means. In one embodiment, the first and / or second layers themselves are arranged to hold the plurality of elements (e.g., in a particular arrangement) between the first and second layers (e.g., during normal use). In one set of embodiments, the impact mitigation structure comprises a support structure and / or retaining structure arranged to hold the plurality of elements (e.g., in a particular arrangement) between the first and second layers (e.g., during normal use). Preferably, the support structure and / or retaining structure are arranged to allow (e.g., to allow release of) the plurality of elements to roll when the impact mitigation structure (e.g., the second layer of the impact mitigation structure) is subjected to an impact (e.g., an impact having at least a particular force).

[0081] The elements may be held (e.g., in a particular arrangement) in the support and / or retaining structure between the first and second layers by any suitable and desirable retaining means, such as by one or more of gravity, static electricity, friction, grooves, one or more magnets, and adhesive.

[0082] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: an inner shock-absorbing layer; and an outer reactive layer disposed over at least a portion of the impact absorbing layer; Equipped with The reaction layer comprises a support structure and / or a retaining structure and a plurality of elements held by the support structure and / or the retaining structure; and The support structure and / or the maintaining structure are configured so that the elements of the reaction layer roll when the reaction layer is subjected to an impact, in order to promote movement of the reaction layer and the shock absorbing layer relative to each other.

[0083] It will be appreciated, therefore, that the present invention also provides a helmet including an impact mitigation structure having an inner impact-absorbing layer (e.g., similar to the first inner layer described herein) and an outer reactive layer on the impact-absorbing layer (e.g., excluding any additional second outer layer). The reactive layer provides a support and / or retention structure for holding a plurality of elements within the support and / or retention structure on the first layer, e.g., in a specific arrangement. When the impact mitigation structure (e.g., the reactive layer of the impact mitigation structure) is impacted, the plurality of elements are configured to roll, facilitating movement of the reactive layer relative to the impact absorbing layer. This also serves to convert a portion of the energy from the impact into movement of the layers relative to each other. This serves to absorb, deflect, and / or dissipate energy from the impact, preventing it from being transmitted to the impact absorbing layer and the head that the helmet is intended to protect.

[0084] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may include any (e.g., all) of the optional and preferred features outlined herein with respect to any of the other aspects and embodiments of the invention. For example, preferably, the elements are held within the support and / or retaining structure by one or more of gravity, electrostatic force, friction, grooves, one or more magnets, and adhesive. Preferably, the elements are held in a specific arrangement within the support and / or retaining structure. Preferably, the elements of the reactive layer (e.g., their specific arrangement) are configured to be disturbed (e.g., so that the elements are capable of rolling) when the reactive layer is impacted, thereby promoting movement of the reactive layer and the impact absorbing layer relative to one another.

[0085] In one embodiment, the retaining structure is arranged to retain the elements (e.g., within the retaining structure) when the impact mitigation structure is subjected to an impact (e.g., an impact having at least a certain force). This helps to prevent the elements from being released, for example, onto the face of a helmet wearer, when the impact mitigation structure is subjected to an impact. Therefore, preferably, the retaining structure at least partially encapsulates and / or surrounds the elements. The retaining structure surrounds the elements on one side, and the first layer or the second layer surrounds the elements on the other side. Thus, for example, the retaining structure may be arranged to retain the elements relative to the first layer or the second layer. Preferably, the retaining structure extends over at least a portion of the first layer or the second layer, for example, to retain the elements relative to the first layer or the second layer, respectively.

[0086] In some embodiments, the retaining structure substantially completely encapsulates and / or surrounds the plurality of elements, which may prevent the plurality of elements from being released when the impact mitigating structure is impacted, and may allow the retaining structure including the plurality of elements to be manufactured as separate components.

[0087] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: an inner shock-absorbing layer; and an outer reactive layer disposed over at least a portion of the impact absorbing layer; Equipped with the reaction layer comprising a support structure and the plurality of elements held by the support structure; the retaining structure substantially completely encloses and / or surrounds the plurality of elements; the support structure is configured to cause a plurality of elements of the reactive layer to roll to facilitate movement of the reactive layer and the shock absorbing layer relative to each other when the reactive layer is subjected to an impact; and The retaining structure is configured such that the elements are retained within the retaining structure when the reaction layer is impacted.

[0088] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0089] Where the retaining structure at least partially (e.g. substantially completely) encapsulates and / or surrounds the plurality of elements, preferably the retaining structure is configured such that the first and / or second layer (e.g. via the retaining layer(s) of the retaining structure) can engage with at least some (e.g. all) of the plurality of elements when the impact mitigation structure is subjected to an impact (e.g. an impact having a force equal to or greater than a particular (e.g. tangential) force).

[0090] Preferably, the retaining structure comprises two layers, wherein the plurality of elements are retained (e.g., sandwiched) between the two layers of the retaining structure. Thus, preferably, the retaining structure comprises a first retaining layer between the plurality of elements and the first layer of the impact mitigation structure, and a second retaining layer between the plurality of elements and the second layer of the impact mitigation structure.

[0091] The two layers of the retention structure are preferably joined (e.g., sealed) together around (e.g., the periphery of) the plurality of elements, for example, by adhesive, heat pressing, or ultrasonic welding. The retention structure can thus take the form of a pouch or bag that contains (and retains) the plurality of elements.

[0092] In some embodiments, the impact mitigation structure comprises both a support structure (e.g., arranged to hold the plurality of elements in a particular arrangement) and a retaining structure (e.g., arranged to maintain the plurality of elements when the impact mitigation structure is subjected to an impact). For example, the support structure can hold the plurality of elements (e.g., in a particular arrangement), and the retaining structure can maintain the support structure on the first layer or the second layer.

[0093] Preferably, to facilitate movement of the reactive layer and the shock absorbing layer relative to one another, the elements of the reactive layer are configured to be released from the reactive layer (e.g., a particular arrangement of the reactive layer) (e.g., from a particular arrangement, e.g., from the support structure and / or into the retaining structure) when the reactive layer is impacted. In some embodiments, movement of the reactive layer and the shock absorbing layer relative to one another simply involves rolling of the elements (e.g., in fixed positions), but preferably also involves displacement of one or more (e.g., all) of the elements (e.g., from a particular arrangement), displacement of the support structure and retaining structure of the reactive layer relative to the shock absorbing layer.

[0094] The plurality of elements may be attached to, embedded in, and / or housed in a support structure and / or retaining structure such that the plurality of elements are held in a particular arrangement. Preferably, the support structure and / or retaining structure is configured to maintain the plurality of elements in a particular arrangement unless (and until) the shock mitigating structure is subjected to a force greater than or equal to a particular force.

[0095] In some embodiments, the support and / or retaining structure is formed by the first and / or second layer (e.g., a portion of or feature of the first and / or second layer), e.g., complementary to the plurality of elements. The first and / or second layer can comprise (e.g., be provided with) a support and / or retaining structure (e.g., a housing or (e.g., flexible) layer) that holds the plurality of elements in a particular arrangement, e.g., sandwiched between (i.e., between) the first and second layer. In one set of embodiments, the plurality of elements may be arranged such that (e.g., when the impact mitigation structure is impacted) the first and / or second layer (e.g., a support structure of the first and / or second layer) releases the plurality of elements (e.g., the plurality of elements housed by or contained between the first and / or second layer) from the first and / or second layer (e.g., a housing formed by the first and / or second layer), thereby disturbing the plurality of elements.

[0096] In one set of embodiments, the reactive layer comprises a support structure (e.g., separate from the first and second layers) arranged to hold the plurality of elements in a particular arrangement. In these embodiments, preferably, the support structure is held (e.g., sandwiched) between the first and second layers. The support structure can be held between the first and second layers in any suitable and desired manner. For example, the support structure may simply be sandwiched (e.g., held by friction) between the first and second layers. In some embodiments, the support structure is attached to the first and / or second layer, for example, by an adhesive or bonding agent.

[0097] In one set of embodiments, the support structure (whether as part of the first layer, second layer, or reaction layer) comprises a plurality of locating points arranged to hold a plurality of elements (respectively) within the support structure, e.g., in a particular arrangement. In one embodiment, the support structure (e.g., the plurality of locating points of the support structure) comprises a plurality of recesses (e.g., in a surface of the support structure). The recesses may be formed by a plurality of protrusions from the surface of the support structure.

[0098] Preferably, each of the plurality of recesses is arranged to hold each of the plurality of elements in a specific (e.g., fixed) position (i.e., within the recess) so that the plurality of elements is held on the support structure, e.g., in a specific arrangement. Thus, preferably, the plurality of recesses are arranged to allow the plurality of elements to roll, e.g., to be released from the support structure (e.g., from a specific arrangement on the support structure), when the shock mitigation structure is impacted. Preferably, the plurality of recesses are arranged to allow the plurality of elements to translate (e.g., displace) and / or roll and rotate freely when the shock mitigation structure is impacted.

[0099] In one embodiment, the support structure (e.g., the plurality of positioning points of the support structure) comprises a plurality of connectors for connecting the plurality of elements to the support structure and holding the plurality of elements in the support structure (e.g., in a specific arrangement on the support structure). Preferably, each element of the plurality of elements is connected to a respective connector of the plurality of connectors. Preferably, the plurality of elements are arranged to disconnect (e.g., separate or detach) from the plurality of connectors when the shock mitigating structure (e.g., the second layer of the shock mitigating structure) is subjected to an impact, thereby allowing the plurality of elements to roll and / or, for example, to become disturbed (e.g., released) from the specific arrangement, e.g., allowing the plurality of elements to translate (e.g., displace) and / or rotate freely.

[0100] As noted above, in some embodiments, the plurality of elements comprises a plurality of discrete elements, e.g., when held to (and released from) a support structure (e.g., in a particular arrangement on the support structure). However, in some embodiments, the plurality of elements is connected (e.g., integrally) to a plurality of connectors and thus, e.g., to the support structure.

[0101] The connectors may comprise protrusions from a surface of the support structure to which the elements are connected. In one embodiment, the elements are attached (e.g., impregnated or bonded) directly to the first and / or second layer (e.g., the support structure of the first and / or second layer). Thus, for example, the elements may be formed on (e.g., directly, integrally with) the first and / or second layer. Preferably, the elements are arranged to disconnect (e.g., separate or detach) from the first and / or second layer (e.g., the support structure of the first and / or second layer) when the impact mitigation structure (e.g., the second layer of the impact mitigation structure) is impacted, thereby allowing the elements to roll (e.g., be disturbed (e.g., released) from the support structure (e.g., a particular arrangement of the support structure). In these embodiments, the plurality of elements is disrupted by the force of the impact overcoming (e.g., severing) the chemical and / or physical bonds between the plurality of elements and the first layer and / or second layer (e.g., the supporting structures of the first layer and / or second layer).

[0102] In one embodiment, the support structure comprises a rigid structure formed, for example, from a polymer (e.g., a thermopolymer), which may be the same material from which the first layer and / or second layer (or, e.g., coating thereof) are formed.

[0103] In one set of embodiments, the support structure (e.g., of the reaction layer) comprises a flexible or compressible layer, such as a gel, foam, or adhesive. For example, the elements may be impregnated or embedded in a gel, foam, or adhesive to hold the elements to the support structure (e.g., in a particular arrangement on the support structure). The flexible or compressible layer preferably has a thickness greater than a (e.g., largest) dimension of the elements, e.g., between 0.1 mm and 5 mm, e.g., between 1 mm and 4 mm, e.g., between 2 mm and 3 mm.

[0104] In one set of embodiments, the retaining structure comprises a flexible (e.g., polymeric, fabric, or metallic) layer (such as a wrapping layer or retaining layer) formed on or around the plurality of elements to retain the plurality of elements in the retaining structure (e.g., in a particular arrangement in the retaining structure). In one set of embodiments, the retaining structure comprises two flexible (e.g., polymeric, fabric, or metallic) retaining layers that substantially completely encapsulate and / or surround the plurality of elements. The flexible layer(s) can retain a support structure (which itself retains the plurality of elements) to the impact mitigating structure.

[0105] The flexible (e.g., fiber) layer(s) may comprise a flexible material such as a woven fabric, mesh, fiber, or cloth. When the flexible layer(s) has one or more (preferably multiple) holes therein (e.g., in the mesh or fiber), the (respective) dimensions of the hole(s) are preferably smaller than the (respective) dimensions of the elements, preferably preventing the elements from passing through the holes in the flexible layer. This helps to maintain the elements within the maintaining structure. The flexible or compressible layer is preferably thinner than the (e.g., largest) dimension of the elements, e.g., less than 2 mm, e.g., less than 1 mm, e.g., less than 0.5 mm, e.g., less than 0.1 mm.

[0106] If the elements are held in place (during normal use) by gel, foam or adhesive, then preferably the elements are configured to release from the gel, foam or adhesive when the shock absorbing structure is impacted, e.g., above a certain (threshold) force. Preferably, the elements are configured to release from the gel, foam or adhesive by rolling (e.g., away from the gel, foam or adhesive), rather than, for example, by breaking a bond with the gel, foam or adhesive.

[0107] The manner in which the elements are held in place may be configured to release the elements when the crash mitigating structure is subjected to an impact (e.g., an impact having a force above a particular force). Preferably, the elements (e.g., each) are held in place (e.g., to one or more other surfaces, layers and / or other components of the crash mitigating structure) by a bond (e.g., adhesive), and one or more (e.g., all) of the elements are configured to release from their respective bonds by peeling away from their respective bonds (e.g., when the crash mitigating structure is subjected to an impact having a force above a particular force).

[0108] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and one or more connectors extending between the first inner layer and the second outer layer; Equipped with The first inner layer and / or the second outer layer are configured to peel from one or more connectors when the shock absorbing structure is subjected to an impact, for example, an impact having a force equal to or greater than a certain force.

[0109] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0110] For example, one or more connectors (attached to one or both of the first inner layer and second outer layer, preferably connecting the first inner layer to the second outer layer) may comprise a plurality of elements and / or a method for holding them in place. Preferably, therefore, the plurality of elements are attached to one or both of the first inner layer and second outer layer by respective (e.g. adhesive) bonds, and one or more (e.g. all) of the plurality of elements and / or their respective bonds are configured to delaminate from the first inner layer and / or second outer layer when the impact mitigating structure is subjected to an impact (e.g. having a force above a certain force).

[0111] Preferably, the one or more connectors (peel of the one or more connectors) are configured to release one or both of the first inner layer and the second outer layer from the connectors, and therefore from each other, when the shock mitigating structure is subjected to an impact (e.g., having a force above a certain force). Preferably, the one or more connectors are configured to release by rotation, e.g., the one or more connectors are configured to rotate upon impact. In one embodiment, the one or more connectors have an hourglass-like shape.

[0112] Preferably, the flexible layer(s) of the retention structure are arranged to stretch (e.g., tangentially) when the shock mitigating structure is impacted. This may help to prevent the flexible layer from tearing on impact, and thus help to maintain the elements within the retention structure. Thus, preferably, the flexible layer(s) of the retention structure are arranged not to tear, break, rupture, and / or sever (i.e., remain intact) when the shock mitigating structure is impacted, so as to maintain the elements therein.

[0113] The flexible layer(s) may be arranged to stretch elastically (and thus may be configured to substantially return to their original shape after being stretched), or the flexible layer(s) may be arranged to stretch plastically (and thus may be configured not to return to their original shape after being stretched).

[0114] Therefore, preferably the support structure and / or retention structure are arranged such that the shock absorbing structure substantially recovers to its original shape and / or position after being subjected to an impact.

[0115] In some embodiments, the flexible layer(s) of the retention structure are arranged to tear when the impact mitigation structure is subjected to an impact, for example, an impact above a certain (threshold) force. The flexible layer(s) may be arranged to tear after stretching (e.g., after a certain amount of stretching), or the flexible layer(s) may be arranged to tear without substantial stretching (e.g., in a tangential direction).

[0116] The retaining structure (e.g., the flexible layer(s) of the retaining structure) can be attached to the remainder of the shock mitigating structure in any suitable and desired manner. In one embodiment, the retaining structure is attached to the same portion of the shock mitigating structure that is adjacent to the reactive layer. Thus, for example, if the reactive layer is adjacent to the first layer and / or the second layer (and, e.g., contacts the first layer and / or the second layer, respectively, when the shock mitigating structure is impacted), then preferably the retaining structure is attached to the first layer and / or the second layer, respectively.

[0117] In one embodiment, the retaining structure is attached to a portion of the shock mitigation structure on an opposite side of the retaining structure from the plurality of elements, e.g., a portion of the shock mitigation structure adjacent to the retaining structure. Thus, for example, if the retaining structure is adjacent to the first layer and / or the second layer, the retaining structure is preferably attached to the first layer and / or the second layer, respectively, of the shock mitigation structure. If the retaining structure comprises first and second retaining layers between the plurality of elements and the first and second layers, respectively, of the shock mitigation structure, the first and / or second retaining layers are preferably attached to the first layer and / or the second layer, respectively, of the shock mitigation structure.

[0118] The retaining structure may (eg, instead of or as well as) be attached to the shock absorbing layer (eg, through or via the harder outer layer).

[0119] The retaining structure may be joined to the remainder of the shock absorbing structure, for example, at any suitable and desired portion thereof. The retaining structure may be joined, for example, by ultrasonic welding or heat pressing.

[0120] The retaining structure may be secured to the remainder of the shock absorbing structure, for example, the retaining structure (e.g., a flexible layer of the retaining structure) may be secured between the first layer and the second layer, or between the first (or second) layer and the shock absorbing layer. The retaining structure may be integrally formed with the remainder of the shock absorbing structure, for example, the retaining structure (e.g., a flexible layer of the retaining structure) may be integrally formed with one or more of the first layer, the second layer, and the shock absorbing layer.

[0121] The retention structure may be attached to the remainder of the shock mitigating structure by an adhesive, for example, the retention structure (e.g., flexible layer(s) of the retention structure) may be attached to the first and / or second layer of the shock mitigating structure by an adhesive. If the retention structure comprises one or more (e.g., flexible) retention layers, the retention layer(s) may be attached to the remainder of the shock mitigating structure (e.g., the first and / or second layers of the shock mitigating structure) during an assembly process to manufacture the shock mitigating structure. For example, various components of the shock mitigating structure (e.g., various components of the reaction layers of the shock mitigating structure) may be assembled and then attached together such that the retention layers are secured (by any suitable and desired means) to the remainder of the shock mitigating structure.

[0122] The retaining structure may be attached to the remainder of the impact mitigation structure by one or more fasteners, such as fasteners that secure the retaining structure to one or more of the first layer, the second layer, and the impact absorbing layer. The retaining structure may be attached to the remainder of the impact mitigation structure via one or more (e.g., interconnecting) notches and / or protrusions. For example, the retaining structure may be attached to one or more of the first layer, the second layer, and the impact absorbing layer via one or more notches and / or protrusions in those layers. Two or more of the first layer, the second layer, and the impact absorbing layer may include complementary notches and protrusions (e.g., protrusions that extend into the respective notches) between which the retaining structure is secured.

[0123] When the impact mitigation structure comprises a first layer, a second layer, and a retaining structure, for example, the first layer and the second layer may be directly attached to each other, the first layer and the second layer may be attached to each other via an intermediate component, and / or the first layer and the second layer may be attached to each other via a reactive layer (e.g., a retaining structure for the reactive layer).

[0124] In one set of embodiments, the first and second layers are attached directly to one another, for example by heat pressing, ultrasonic welding, or adhesive.

[0125] In one set of embodiments, the first and second layers are attached to one another via an intermediate component, e.g., by one or more struts and / or spacers extending between the first and second layers. In one embodiment, the strut(s) and / or spacer(s) are compressible and preferably configured to compress when the impact mitigation structure is impacted (e.g., when the impact mitigation structure is impacted with a force above a certain force), e.g., such that the first and / or second layers contact at least some (e.g., all) of the elements.

[0126] Thus, preferably, the first and second layers are spaced apart (e.g., the posts and / or spacers are so sized) from one another, at least over the area in which the elements are distributed, by a distance that is greater than the corresponding dimension of the elements, e.g., the posts and / or spacers are arranged to space the first and / or second layers from the elements. The first and second layers can be spaced apart (e.g., by the posts and / or spacers) by any suitable and desired distance, for example, between 1 mm and 5 mm, e.g., between 2 mm and 4 mm, e.g., about 3 mm.

[0127] Spacing the first and second layers apart by a distance greater than the size of the elements helps reduce friction between the first and / or second layers and the elements. Providing posts or spacers to attach the first and second layers together, while simultaneously spacing the first and second layers apart at and around these attachment points, also helps reduce friction between the first and second layers at or near these attachment points (e.g., locations where any of the elements may not be present nearby) when the impact mitigation structure is impacted. This helps reduce the risk of geometric locking between the first and second layers if they move relative to each other when the impact mitigation structure is impacted.

[0128] If the strut(s) and / or spacer(s) are compressible, they can be formed, for example, from foam (e.g., foam tape). The foam tape can be arranged to delaminate from the first layer and / or second layer when the impact mitigation structure is impacted (e.g., with a force above a certain force). The delamination of the foam tape (as opposed to, for example, shearing of the foam tape) can help control the specific force that displaces the first and second layers relative to one another to disrupt the multiple elements.

[0129] In one embodiment, the strut(s) and / or spacer(s) are arranged (e.g., hinged) to pivot (e.g., at either or both ends attached to the first and second layers) when the impact mitigating structure is impacted, thereby helping to allow the reactive layer (e.g., of the retaining structure and / or support structure) to move across and / or between the (e.g., doubly curved) surfaces of the first and / or second layers.

[0130] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; a reactive layer disposed between the first inner layer and the second outer layer, the reactive layer comprising a plurality of elements held between the first inner layer and the second outer layer; and one or more struts and / or one or more spacers extending between the first inner layer and the second outer layer; Equipped with The reactive layer is arranged such that when the second layer is impacted, the one or more struts and / or one or more spacers pivot so that one or both of the first inner layer and the second outer layer contact the reactive layer, thereby configuring multiple elements of the reactive layer to roll to promote movement of the first inner layer and the second outer layer relative to each other.

[0131] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0132] Preferably, at least a portion of the reactive layer (e.g., the retaining structure and / or the support structure of the reactive layer) is flexible, for example, the reactive layer (e.g., the retaining structure and / or the support structure of the reactive layer) comprises one or more hinge lines extending across at least a portion (e.g., all) of the reactive layer (e.g., the retaining structure and / or the support structure of the reactive layer). Preferably, the reactive layer (e.g., the retaining structure and / or the support structure of the reactive layer) is arranged to curve at at least a portion (e.g., all) of the one or more hinge lines when the shock-absorbing structure is impacted. This helps the reactive layer (e.g., the retaining structure and / or the reactive layer of the support structure) to bend upon impact to conform to the (e.g., doubly curved) surfaces of the first and / or second layers as they move relative to each other.

[0133] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and a reactive layer disposed between the first inner layer and the second outer layer, the reactive layer comprising a plurality of elements held between the first inner layer and the second outer layer; Equipped with the first inner layer is curved; the second outer layer is curved; the reactive layer comprising one or more hinge lines extending across at least a portion of the reactive layer; The reactive layer is arranged to facilitate movement of the first inner layer and the second outer layer relative to one another when the second layer is impacted, and to bend at least a portion of one or more hinge lines to accommodate the curved first inner layer and the curved second layer as they move relative to one another.

[0134] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention.

[0135] The hinge line in the reactive layer may comprise a springy (e.g., crimped) portion of the reactive layer, such as a reactive layer of the support structure (e.g., a reactive layer of the flexible layer(s) of the support structure), which may allow the reactive layer to flex as well as extend (stretch) when the impact mitigating structure is impacted.

[0136] Preferably, the strut(s) and / or spacer(s) are configured (e.g. have a thickness or diameter) such that when the strut(s) and / or spacer(s) pivot when the impact mitigating structure is impacted, multiple elements roll on the strut(s) and / or spacer(s).

[0137] In one embodiment, the first layer and the second layer are attached to each other at one or more points around the perimeter (e.g., outside the perimeter) of the reactive layer (e.g., the supporting structure of the reactive layer). In one set of embodiments, the first layer and the second layer are attached to each other (e.g., at one or more points) through the reactive layer (e.g., the supporting structure of the reactive layer) but avoid the perimeter of the reactive layer (e.g., the supporting structure of the reactive layer). In some embodiments, the first layer and the second layer are attached to each other both around the perimeter and through the reactive layer.

[0138] The point(s) at which the first and second layers are attached to one another may comprise discrete (spaced) point(s) and / or continuous point(s) (e.g., points extending along lines). These line(s) may, for example, define distinct regions of the reactive layer.

[0139] In some embodiments, the support post(s) and / or spacer(s) extend through the reactive layer (e.g., the supporting structures of the reactive layer). In some embodiments, one or more points at which the first and second layers are attached to one another correspond to or are located at one or more hinge lines of the reactive layer. Thus, preferably, the support post(s) and / or spacer(s) extend through one or more hinge lines of the reactive layer (e.g., the supporting structures of the reactive layer).

[0140] The attachment of the first and second layers to one another, e.g., via the support(s) and / or spacer(s), can define a hinge line(s) of the reactive layer (e.g., the supporting structure of the reactive layer). Thus, in some embodiments, the support(s) and / or spacer(s) are arranged to pivot at the hinge line of the reactive layer (e.g., the supporting structure of the reactive layer), and the reactive layer (e.g., the supporting structure of the reactive layer) is arranged to bend at the hinge line of the reactive layer (e.g., the supporting structure of the reactive layer).

[0141] While one support structure and / or one retaining structure may be used to hold multiple elements, for example, in a particular arrangement, in one set of embodiments, the impact mitigation structure comprises multiple (e.g., discrete) support structures and / or multiple (e.g., discrete) retaining structures, each arranged to hold the multiple elements on its respective support structure and / or retaining structure (e.g., in its respective particular arrangement). This may (e.g., depending on the nature of the impact) serve to increase the specific force required to disturb the multiple elements, or to allow only a portion of the multiple elements to be disturbed at a time. This may serve to control the magnitude of the specific force required to disturb the multiple elements, or to control the movement of the first and second layers relative to each other so as to limit it to the location of the impact.

[0142] Thus, the reactive layer may comprise multiple discrete portions, each comprising multiple elements, e.g., a respective support structure and / or retaining structure. The discrete portions of the reactive layer may be defined (delineated) by one or more hinge lines of the reactive layer. One or more (e.g., all) of the discrete portions of the reactive layer and support structure and / or retaining structure may comprise any or each of the preferred and optional features outlined herein for the individual reactive layer, support structure and / or retaining structure.

[0143] When the impact mitigating structure (e.g., the second layer or the reactive layer of the impact mitigating structure) is subjected to an impact (e.g., an impact of above a certain force), e.g., according to one or more of the embodiments described herein, the plurality of elements (e.g., a particular arrangement of the plurality of elements) can be configured such that the plurality of elements roll (e.g., such that they are disturbed and capable of rolling) in any suitable and desired manner to promote movement of the first layer relative to the second layer (or reactive layer) relative to each other, depending on how the support structure and / or retaining structure holds the plurality of elements, e.g., in a particular arrangement.

[0144] In one set of embodiments, the support structure is arranged to fail (e.g., rupture and / or collapse) when the shock mitigating structure (e.g., the second layer or the reactive layer of the shock mitigating structure) is impacted, for example when it is impacted with a force above a certain (e.g., threshold) force. Preferably, the elements are arranged such that they are released from the particular arrangement (and are e.g., free to move) when the support structure is broken. Preferably, the elements are arranged such that they are free to move (e.g., translate and / or rotate) when they disrupt (e.g., are released from) the particular arrangement, allowing the first and second layers to move (e.g., slide) relative to each other (or the first layer relative to the reactive layer).

[0145] In one embodiment, one or more (e.g., all) of the plurality of elements are connected together (e.g., with connectors extending therebetween), e.g., in, as part of, in addition to, or instead of, the support structure and / or the maintaining structure. In one embodiment, one or more (e.g., all) of the plurality of elements are connected to one or more (e.g., all) of the plurality of elements. Thus, for example, pairs of elements may be connected, (e.g., linear) strings of elements may be connected, or (two- or three-dimensional) webs or arrays of elements may be connected.

[0146] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and a plurality of elements held between the first inner layer and the second outer layer; Equipped with the plurality of elements are held between the first inner layer and the second outer layer by a plurality of connectors extending between the plurality of elements and one or more of the first inner layer, the second outer layer, and other of the plurality of elements; the plurality of connectors are configured to release at least some of the plurality of elements when the shock absorbing structure is subjected to an impact; and The released element is configured to facilitate movement of the first inner layer and the second outer layer relative to one another.

[0147] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention, and thus preferably the plurality of elements form at least part of the reactive layer.

[0148] One or more (e.g., all) of the plurality of elements can be connected together in any suitable and desired manner. In one embodiment, the elements are connected together by one or more of strings, cords, threads, springs, tapes, webbing, mechanical fasteners (latches, hooks, gates, etc.), and rods. The connections between the elements can be one or more of the following: flexible, rigid, plastic, elastic, brittle, and frangible. Thus, the connections between the elements can be configured to stretch, deform, peel, break, sever, and rupture when the impact mitigation structure is impacted, for example, when the impact exceeds a threshold. Preferably, this operates to release the plurality of elements when the impact mitigation structure is impacted.

[0149] In some embodiments, the connection(s) between the elements are configured to remain intact (e.g., not stretch, not deform, not break, not sever, not break, or one or more of) when the impact mitigation structure is impacted. In these embodiments, the elements may be configured to release differently (e.g., from a particular arrangement), for example, from the support structure, within the retaining structure, or from connections to, for example, the first layer and / or the second layer.

[0150] The connection(s) between the elements may be taut (and, e.g., unable to stretch) or slack (and, e.g., able to stretch, e.g., tighten, e.g., when the crash mitigation structure is impacted). Tensioning or slacking the connections may help to control the force (e.g., tensile force) at which the connections stretch, deform, break, sever, or rupture when the crash mitigation structure is impacted.

[0151] In some embodiments, the connection(s) between the elements extend through or are connected to one or more of the other components (e.g., layers) of the shock mitigating structure. The connection(s) between the elements may be configured to at least partially release from the other components (e.g., layers) of the shock mitigating structure when the shock mitigating structure is subjected to an impact, e.g., an impact above a threshold, e.g., in addition to the connection(s) between the elements being configured to one or more of stretch, deform, break, sever, and rupture. In some embodiments, the connection(s) between the elements may be configured to at least partially remain through or be connected to one or more of the other components (e.g., layers) of the shock mitigating structure when the shock mitigating structure is subjected to an impact, e.g., an impact above a threshold.

[0152] In one embodiment, one or more (e.g., all) of the plurality of elements are configured to be at least partially maintained by the support structure when the shock mitigation structure is subjected to an impact, e.g., above a threshold. In this embodiment, preferably, one or more (e.g., all) of the plurality of elements are configured to roll relative to (e.g., at least partially within) the support structure. For example, the support structure may include a housing for one or more (e.g., all) of the plurality of elements, where the plurality of elements are configured to roll relative to (e.g., at least partially within) the housing.

[0153] Preferably, one or more portions of one or more (e.g., all) of the plurality of elements are exposed (e.g., protrude) from the support structure (e.g., the housing of the support structure), and wherein the exposed portion(s) of one or more (e.g., all) of the plurality of elements are configured to contact (and e.g., roll against) one or both of the first layer and the second layer.

[0154] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; a second outer layer; and a plurality of elements held between the first inner layer and the second outer layer; Equipped with the plurality of elements are held in the housing between the first inner layer and the second outer layer such that at least a portion of the plurality of elements are exposed to one or both of the first inner layer and the second outer layer; the exposed portions of the plurality of elements are configured to contact one or both of the first inner layer and the second outer layer when the impact mitigation structure is impacted; and The elements are configured to roll within the housing to facilitate movement of the first inner layer and the second outer layer relative to one another.

[0155] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention, and thus preferably the plurality of elements form at least part of the reactive layer.

[0156] The first and second layers may, for example, be designed to perform different (or similar) functions in the impact mitigation structure. In one set of embodiments, one or both of the first and second layers comprise an impact (energy) absorbing layer. In at least preferred embodiments, such an impact absorbing layer is designed to provide some protection against bulk forces caused by an impact. Preferably, therefore, the impact absorbing layer is positioned to absorb at least a portion of the normal component of the forces exerted on the impact mitigation structure during an impact.

[0157] The shock-absorbing layer(s) (first layer and / or second layer) can be formed from any suitable and desired material, such as expanded polystyrene (EPS). In one preferred set of embodiments, the shock-absorbing layer(s) (first layer and / or second layer) comprise a hollow cell structure, for example, a hollow cell structure comprising a plurality of hexagonal cells (in cross section). Preferably, at least a plurality of the cells are tessellated with one another. For example, the shock-absorbing layer(s) (first layer and / or second layer) may comprise a micro-truss lattice or an out-of-plane honeycomb structure.

[0158] Preferably, the shock-absorbing layer comprises a hard coating or layer (e.g., a shell) on the surface (of the first and / or second layer) between which (e.g., in contact with) the reactive layer and has (approximately) the same hardness as the plurality of elements. Preferably, the coating or layer has a hardness greater than that of the first and / or second layer (e.g., the shock-absorbing layer) on which it is provided. For example, the shock-absorbing layer may be coated with (or attached to) a polycarbonate layer (which may, for example, be harder than the material of the shock-absorbing layer). This may help the plurality of elements (if applicable) to roll and thus move relative to the reactive layer, the first layer, and / or the second layer.

[0159] Where the impact mitigating structure comprises a support or retaining structure, preferably the support or retaining structure is arranged to hold a plurality of elements (e.g. within the support structure) adjacent to (e.g. against) the first or second layer. Preferably, the support or retaining structure is attached to the first or second layer such that the support or retaining structure holds a plurality of elements (e.g. multiple elements in the support structure) adjacent to (e.g. against) the first or second layer, respectively.

[0160] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: shock-absorbing layer; a shell layer, the shell layer being harder than the shock absorbing layer; a plurality of elements disposed adjacent to the shell layer; and a support or retention structure positioned to hold the plurality of elements adjacent to the shell layer; Equipped with The support structure, the retaining structure and / or the plurality of elements are configured such that when the shock absorbing structure is subjected to an impact, the plurality of elements contact and roll against the shell layer to promote movement of the shell layer and the retaining structure relative to each other.

[0161] It will be appreciated that the helmet and impact mitigating structure of this aspect of the invention may comprise any (e.g., all) of the optional and preferred features outlined herein with respect to any of the other aspects and embodiments of the invention. For example, preferably, the retention structure is arranged to retain the elements (e.g., within the retention structure and / or between the retention structure and the shell layer) when the elements are released after an impact. Preferably, the support structure and / or retention structure are attached to the shell layer. Preferably, the support structure, retention structure, and / or elements together form a reactive layer. Preferably, there is no intermediate layer (e.g., a low-friction layer and / or retention structure (e.g., a flexible layer)) between the shell layer and the elements, e.g., the elements are held directly to the shell layer by the support structure or retention structure. Preferably, the shell layer and / or elements comprise a high-friction material and / or coating.

[0162] The shell layer, the shock absorbing layer, the support or retention structure, and the plurality of elements may be arranged relative to one another in any suitable and desired manner, for example, according to the embodiments outlined herein.

[0163] In some embodiments, the retaining or supporting structure and the plurality of elements are present between the shock absorbing layer and the shell layer. In some embodiments, the shell layer is attached to or comprises a portion of the shock absorbing layer, for example as a layer (inner or outer layer) of the shock absorbing layer or a coating of the shock absorbing layer, and the retaining or supporting structure and the plurality of elements are present inside or outside the shell layer.

[0164] In some embodiments, the support structure or retention structure is the innermost or outermost part of the shock mitigation structure. In some embodiments, the shock mitigation structure comprises an additional layer (e.g., an inner or outer layer), and the retention structure or support structure and multiple elements are between the additional layer and the shell layer. Thus, in these embodiments, the additional layer may be the innermost or outermost part of the shock mitigation structure. The additional layer preferably comprises a thin and / or hard layer (e.g., a shell layer). Preferably, this additional layer comprises a second layer as outlined herein. In such embodiments, the optional and preferred features outlined herein in relation to the second layer may apply to the additional layer as well.

[0165] In one set of embodiments, the second layer comprises a flexible layer (e.g., a metal, polymer, and / or fabric layer). Thus, in some embodiments, the second layer can function as a retaining or support structure for multiple elements of the reactive layer. In such embodiments, the optional and preferred features outlined herein in relation to the retaining or support structure can apply to the second layer as well.

[0166] In one set of embodiments, the second layer comprises an outer shell (e.g., elastic, rigid). If the second layer comprises a shock-absorbing layer, the shock-mitigating structure can comprise an (additional) outer shell, with the second layer disposed (e.g., sandwiched) between the reactive layer and the outer shell. If the shock-mitigating structure comprises an additional outer shell, it is the outer shell that receives the impact (thereby allowing the second layer to be impacted (or receive the impact) through the outer shell).

[0167] Preferably, the thickness of the outer shell is (e.g., significantly) less than the thickness of the first layer. When the impact mitigation structure comprises a second layer and an outer shell, preferably, the thickness of the outer shell is (e.g., significantly) less than the thickness of the second layer. Thus, the outer shell may (if necessary) comprise, for example, a membrane at least partially covering the reaction layer and / or the second layer. Preferably, the membrane comprises a bilayer, eg, covering (enveloping) both sides of the reactive layer (eg, multiple elements of the reactive layer).

[0168] Preferably, the outer shell is formed from a rigid material such as a thermoplastic, e.g., polycarbonate, carbon fiber, or composite material, but may be made from any suitable and desired material. Preferably, the material forming the outer shell has a high strength to weight ratio.

[0169] Preferably, the surfaces of the first and second layers between which the reactive layer is disposed, as well as, for example, the outer shell, if provided, have low-friction surfaces, e.g., low-friction surfaces with a (relatively) large surface area. For example, one or more (e.g., all) of the first layer, the second layer, and, for example, the outer shell, are provided with a low-friction coating and / or formed from a low-friction (e.g., self-lubricating) material at least on their adjacent surfaces. Preferably, the surfaces also have a large relative overlap. The low-friction surfaces and large relative overlap can help the first layer, the second layer, and the reactive layer (and, for example, the outer shell) to move relative to each other when subjected to an impact.

[0170] In one embodiment, the impact mitigating structure comprises a low-friction interface (e.g., layer) between one or more (e.g., all) of the first layer, second layer, and elements, provided by a (low-friction) material of the first layer, second layer, and / or elements, a (low-friction) coating of the first layer, second layer, and / or elements, and / or an additional (low-friction) layer between one or more (e.g., all) of the first layer, second layer, and elements.

[0171] The low-friction interface can be located in (substantially) all of the regions between the first and second layers, e.g., in all regions where a reactive layer and a plurality of elements are present. In some embodiments, the low-friction interface and / or the plurality of elements are provided in one or more discrete regions between the first and second layers (and, e.g., not in other regions between the first and second layers). The region(s) where the low-friction interface and / or the plurality of elements are provided may at least partially coincide with one another (e.g., may at least partially overlap), or the region(s) where the low-friction interface and / or the plurality of elements are provided may be distinct from one another (e.g., may not overlap).

[0172] This is believed to be novel and inventive in itself and therefore viewed from a further aspect the present invention provides a helmet comprising an impact mitigating structure, said impact mitigating structure comprising: First inner layer; second outer layer; a plurality of elements held between the first inner layer and the second outer layer; and a low-friction interface disposed between the first inner layer, the second outer layer, and one or more of the plurality of elements; and The plurality of elements and the low-friction interface are configured such that the plurality of elements of the reaction layer roll to promote movement of the first inner layer and the second outer layer relative to one another when the impact mitigation structure is impacted, and / or the low-friction interface is configured to act between one or more of the first inner layer, the second outer layer and the plurality of elements.

[0173] It will be appreciated that the helmets and impact mitigating structures of this aspect of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein in relation to any of the other aspects and embodiments of the invention. Preferably, therefore, the plurality of elements and low friction interface form at least part of the reactive layer.

[0174] Preferably, the surfaces of the first and second layers between which the reactive layer is disposed comprise hard surfaces, e.g., hard surfaces having (approximately) the same hardness as the elements. For example, one or more (e.g., all) of these surfaces of the first layer, the second layer (and, e.g., the outer shell) comprise a hard (e.g., polycarbonate) coating (or an additional layer attached thereto) at least on their adjacent surfaces and / or are formed from a hard material (e.g., polycarbonate). For example, a hard shell(s) (e.g., layer(s)) may be provided between the first and / or second layer and the reactive layer, as opposed to the first and / or second layer being provided with a coating or formed from a hard material. A hard surface (e.g., having (approximately) the same hardness as the elements) may help the first, second, and reactive layers to move relative to one another upon impact.

[0175] In one set of embodiments, the second layer (e.g., or outer shell) is designed to absorb (e.g., remove) at least a portion of any rotational forces resulting from an impact. In preferred embodiments, when the second layer (e.g., or outer shell) is subjected to an impact (e.g., an impact having a force above a certain force), the perturbation (e.g., movement) of the elements allows the second layer to translate (e.g., slide) on the first layer (e.g., by the elements moving between them). Preferably, the elements are arranged to rotate, which can help the second layer translate (e.g., slide) on the first layer with reduced resistance.

[0176] The second layer (e.g., or outer shell) may be arranged to resist fracture upon impact (e.g., an impact above a threshold force). However, in some embodiments, the second layer (e.g., and / or outer shell) is arranged to fracture upon impact (e.g., an impact having a force above a certain force), for example, if the second layer (e.g., and / or outer shell) is (e.g., relatively) thin and / or stiff.

[0177] The first and second layers (e.g., and / or outer shell) may be arranged to separate (e.g., completely) when the crash mitigating structure is subjected to an impact (e.g., an impact having a force above a certain force), e.g., to allow continued movement of the layers relative to each other. Preferably, the (e.g., second) outer layer is arranged to delaminate from the remainder of the crash mitigating structure (so that it can no longer transfer energy to the remainder of the crash mitigating structure) when the crash mitigating structure is subjected to an impact (e.g., an impact having a force above a certain force).

[0178] Preferably, therefore, the outer layer is attached to the remainder of the crash mitigation structure such that the outer layer is configured to peel away from the remainder of the crash mitigation structure when the crash mitigation structure is subjected to an impact (e.g., an impact having a force above a certain force). Preferably, the reactive layer and / or the outer layer are configured such that after the outer layer peels away from the crash mitigation structure, the outer layer is substantially free to move away from the remainder of the crash mitigation structure. This helps to deflect the impact away from the remainder of the crash mitigation structure (e.g., attached to the wearer's head) and reduces the chance of the outer layer becoming geometrically locked to the remainder of the crash mitigation structure, thereby reducing the energy of the impact transmitted to the remainder of the crash mitigation structure.

[0179] If the shock mitigating structure comprises a retaining structure, for example attached to an outer layer, the outer layer is preferably configured to peel away from the retaining structure (for example the (second) retaining layer of the retaining structure) when the shock mitigating structure is subjected to an impact (for example an impact having a force above a certain force). This allows the outer layer to separate from the rest of the shock mitigating structure upon impact, while the retaining structure remains intact, thus allowing the retention of multiple elements.

[0180] Thus, in some embodiments, the retention structure is arranged to remain attached to (a part of) the remainder of the impact mitigation structure (e.g., to the (first) inner layer) when the impact mitigation structure is subjected to an impact (e.g., an impact having a force above a certain force), for example when the outer layer peels off from the remainder of the impact mitigation structure.

[0181] In some embodiments, for example where the retaining structure comprises one or more flexible layers, the outer layer is arranged to remain attached (e.g. stretched and / or deformed) to the rest of the shock mitigating structure (e.g. including the (second) retaining layer of the retaining structure) when the outer layer is displaced less than a certain (threshold) distance relative to the rest of the shock mitigating structure, for example during a first stage of impact. Preferably, the outer layer is configured to delaminate from the retaining structure (e.g. the (second) retaining layer of the retaining structure) when the outer layer is displaced at least a certain (threshold) distance relative to the rest of the shock mitigating structure, for example during a second stage of impact.

[0182] The particular (threshold) distance may be any suitable and desired distance, for example, between 5 mm and 100 mm, for example between 10 mm and 80 mm, for example between 20 mm and 70 mm, for example between 40 mm and 60 mm, for example about 50 mm.

[0183] Thus, in some embodiments (e.g., when the crash mitigating structure is subjected to an impact having a force equal to or greater than a certain force), the outer layer is arranged to attach to the rest of the crash mitigating structure with a displacement of less than a certain (threshold) distance (and the retaining structure is arranged to deform and / or stretch to accommodate this displacement), and then to delaminate from the rest of the crash mitigating structure at the certain (threshold) distance. This helps to provide contact between the various different components of the crash mitigating structure, such that in a first stage of impact the reactive layer can facilitate movement of the first and second layers relative to each other, and in a second stage of impact the outer surface can continue to move away from the rest of the crash mitigating structure, allowing the retaining structure to retain multiple elements.

[0184] Preferably, the manner in which the outer layer is attached to the rest of the impact mitigating structure (e.g., according to any one of the embodiments outlined herein) is configured to facilitate this two-stage behavior.

[0185] The timescale over which an impact acts on the shock mitigating structure, for example the timescale before the outer layer delaminates from the remainder of the shock mitigating structure, can be any suitable and desired timescale, hi one set of embodiments the shock mitigating structure is configured such that when the shock mitigating structure is subjected to an impact (e.g. an impact having a force equal to or greater than a particular force), the outer layer delaminates from the remainder of the shock mitigating structure after less than 50 milliseconds, for example less than 20 milliseconds, for example less than 10 milliseconds, for example less than 5 milliseconds.

[0186] The impact mitigating structure may be any suitable and desirable impact mitigating (e.g., absorbing) structure arranged to mitigate forces in an impact (e.g., absorb energy from an impact). Although the above aspects and embodiments have been described primarily with respect to helmets, applicants understand that the impact mitigating structure of helmets is applicable to other types of impact mitigating structures.

[0187] Thus, viewed from a further aspect, the present invention provides: First inner layer; a second outer layer; and a reactive layer disposed between the first inner layer and the second outer layer, the reactive layer comprising a plurality of elements held between the first inner layer and the second outer layer; A shock absorbing structure comprising: The reactive layer is arranged such that when the second layer is impacted, multiple elements of the reactive layer are configured to roll to promote movement of the first inner layer and the second outer layer relative to one another.

[0188] Viewed from a further aspect, the present invention provides: an inner shock-absorbing layer; and an outer reactive layer disposed over at least a portion of the impact absorbing layer; A shock absorbing structure comprising: The reaction layer comprises the support structure and / or the retaining structure and a plurality of elements held by the support structure and / or the retaining structure; and The support structure and / or the maintaining structure are configured to cause the elements of the reactive layer to roll in order to facilitate movement of the reactive layer and the shock absorbing layer relative to each other when the reactive layer is subjected to an impact.

[0189] It will be appreciated that the impact mitigating structures of these aspects of the invention may comprise any (e.g. all) of the optional and preferred features outlined herein with respect to any of the other aspects and embodiments of the invention. Similarly, the invention provides impact mitigating structures corresponding to all other aspects directed to helmets.

[0190] The impact mitigation structure may be (e.g., form part of) the armor of the vehicle. However, in at least preferred embodiments, the impact mitigation structure is wearable. A wearable impact mitigation structure is preferably positioned to protect a wearer from injury upon impact. For example, the impact mitigation structure may be configured to be worn (e.g., attached) to a person or object (e.g., vehicle) to provide protection against an impact received by the impact mitigation structure. As such, the impact mitigation structure may form part of an element of clothing or body armor. In such an embodiment, preferably, a first layer is positioned closest to (e.g., attached to) the person or object (e.g., vehicle), and disturbance of the elements promotes movement of a second layer (or reaction layer) relative to the first layer.

[0191] In embodiments in which the impact mitigation structure is a helmet, the first layer is preferably the inner layer of the helmet, and the second layer is preferably the outer layer of the helmet. When the impact mitigation structure comprises an outer shell, the outer shell preferably comprises the outer layer of the helmet. These layers are preferably curved, e.g., approximately hemispherical, to help improve the fit of the layers to the head and increase the injury protection provided by the helmet. These features apply equally to other body armor elements, e.g., that fit other parts of the body.

[0192] In embodiments where the impact mitigating structure includes a helmet, it will be appreciated that the present invention may reduce rotation and rotational force transfer of the user's head when the helmet is impacted because the second (and / or reaction) layer is able to translate (e.g., slide or rotate) relative to the first layer and the user's head. By reducing tangential forces on the user's head, the risk of cervical spine injury and brain injury from head impact is further reduced.

[0193] Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0194] Impact mitigation structures serve to protect users or objects by absorbing and / or deflecting the energy of an impact. In oblique impacts, which are a common type of impact, impact mitigation structures can be subjected to large linear and tangential forces. These forces can cause rapid deceleration of the user and / or object, potentially resulting in serious injury. An embodiment of the present invention aims to provide an improved impact mitigation structure that reduces the risk of serious injury during an impact.

[0195] 1 to 37 show shock absorbing structures according to various embodiments of the present invention.

[0196] 1 is a schematic cross-sectional view through a portion of a shock mitigating structure 100. The shock mitigating structure 100 has the following components: a first layer 102, a second layer 104, and a reactive layer 105. The reactive layer 105 is formed from a plurality of discrete elements 106 and is disposed between the first layer 102 and the second layer 104. The plurality of discrete elements 106 are held in a specific arrangement (e.g., a regular array) in the reactive layer 105 between the first layer 102 and the second layer 104.

[0197] The first layer 102 may be an energy absorbing layer, such as for a helmet, and the second layer 104 may be a rigid outer shell. In one particular example, the first layer 102 is an expanded polystyrene liner with a polycarbonate shell coating, and the second layer 104 is a polycarbonate shell. However, it will be appreciated that there are many different materials that are suitable for the first layer 102 and the second layer 104, depending, for example, on the application of the impact mitigating structure 100.

[0198] In Figure 1, the discrete elements are spheres (e.g., balls) 106. Although only four spheres 106 are shown in Figure 1, it will be understood that the impact mitigating structure 100 extends beyond the portion shown in Figure 1 such that the reactive layer 105 can comprise any suitable number of spheres 106. Although the spheres 106 shown in Figure 1 are spherical, the reactive layer 105 can also be formed from other types of spherical or rounded discrete elements.

[0199] The first layer 102 and the second layer 104 are formed to accommodate the spheres 106 therebetween. The first layer 102 and the second layer 104 form a support structure, housing, or container for the spheres 106, thereby holding the spheres 106 in a particular "semi-rigid" arrangement. In this arrangement, the spheres 106 have freedom of movement, while the reaction layer 105 as a whole is fixed between the first layer 102 and the second layer 104. For example, each sphere 106 can move a fixed distance relative to adjacent spheres in the arrangement. However, due to the diameter of the spheres 106 compared to the separation (e.g., distance) between the first layer 102 and the second layer 104, the spheres 106 cannot swap (e.g., change) their positions.

[0200] During use, when the shock mitigating structure 100 (e.g., the second layer (e.g., outer layer) of the shock mitigating structure 100) is subjected to an impact having a force above a certain threshold force, the first layer 102, the second layer 104, and the reactive layer 105 are subjected to forces such that they can no longer provide a support structure, housing, or container for the sphere 106. This may result in the second layer 104 being displaced, broken, or pushed out by the force of the impact. The sphere 106 is disrupted (destroyed) from its particular arrangement in the reactive layer 105 such that it is no longer held in arrangement between the first layer 102 and the second layer 104. The behavior of the sphere 106, the first layer 102, the second layer 104, and the reactive layer 105 after impact is described in more detail in connection with FIG. 11 .

[0201] Figure 2 is a schematic cross-sectional view through a portion of a shock mitigating structure 200 according to another embodiment of the present invention. Similar to the shock mitigating structure 100 shown in Figure 1, the shock mitigating structure 200 shown in Figure 2 comprises a first layer 202, a second layer 204, and a reactive layer 205. Furthermore, the arrangement of these layers relative to each other is the same as that shown in Figure 1.

[0202] 1, the discrete elements of the reactive layer 205 of the impact mitigating structure 200 are spheres 206, 207, 208 of different diameters. In particular, the reactive layer 205 is formed from a plurality of spheres 206, 207, 208 of three different diameters.

[0203] First layer 202 and second layer 204 form a support structure, housing, or container for spheres 206, 207, 208 in the same manner as described in connection with Figure 1. However, due to the difference in size, spheres 206, 207, 208 shown in Figure 2 may have more freedom of movement than sphere 106 shown in Figure 1, particularly upon impact. However, the spheres are still maintained in a semi-rigid arrangement between first layer 202 and second layer 204.

[0204] Figure 3 is a schematic cross-sectional view through a portion of a shock mitigating structure 300 according to another embodiment of the present invention. Similar to the shock mitigating structure 100 shown in Figure 1, the shock mitigating structure 300 of Figure 3 comprises a first layer 302, a second layer 304, and a plurality of spheres 306 forming a reaction layer 305.

[0205] 3, however, each sphere 306 is connected to the first layer 302 by a connector 310. Each connector 310 holds the corresponding sphere 306 in a fixed position, allowing multiple spheres to be held in a fixed arrangement. The connectors 310 and spheres 306 are made from the same material as the first layer 302 and are integrally formed on the first layer 320. When the impact mitigation structure is subjected to an impact above a certain threshold force, the connectors 310 are arranged to fracture, allowing the spheres 306 to be released and move from their previously fixed positions.

[0206] 4 and 5 are schematic cross-sectional views through parts of shock-absorbing structures 400, 500 according to other embodiments of the present invention.

[0207] Similar to the shock mitigating structure 100 shown in Figure 1, in the embodiment shown in Figure 4, the shock mitigating structure 400 includes a first (e.g., shock absorbing) layer 402, a second (e.g., outer shell) layer 404, and a plurality of spheres 406 forming a reactive layer. However, additional mechanisms are provided to hold the spheres 406 in a particular arrangement.

[0208] The first layer 402 includes a number of "dimples" (small depressions), e.g., indentations or recesses, on the surface of the first layer 402. The dimples are sized so that each dimple holds one sphere 406 in a fixed position. These dimples may be spaced at a regular (e.g., uniform) distance from each other throughout the first layer 402 to provide a uniform placement (e.g., array) of the spheres 406 throughout the reaction layer. They may also be spaced according to a geometric distribution.

[0209] When the impact mitigating structure is subjected to an impact above a certain threshold force, sufficient energy is imparted to the sphere to displace it from the dimple in the first layer 402 and release it from its fixed arrangement in the reactive layer.

[0210] Additionally or alternatively, in some embodiments, the spheres 406 may be chemically and / or physically bonded to the first layer 402. This helps to provide an increased threshold force required to disturb and displace the spheres from their fixed positions.

[0211] Figure 5 shows another impact mitigating structure 500 including a first layer 502, a second layer 504, and a plurality of spheres 506 (forming a reactive layer) in a manner similar to the embodiment shown in Figure 4. The spheres 506 are impregnated or bonded to the second layer 504 to hold the spheres 506 in a particular arrangement.

[0212] When the shock mitigating structure is subjected to an impact above a certain threshold force, sufficient energy is imparted to overcome the chemical and / or physical bonds of the spheres 506 to the second layer 504 and release them from their fixed arrangement in the reactive layer. The spheres 506 can then move from their previous fixed arrangement.

[0213] 6A is a schematic cross-sectional view through a portion of a shock mitigating structure 600 according to another embodiment of the present invention. Similar to the shock mitigating structures shown in previous figures, the shock mitigating structure 600 comprises a first (e.g., shock absorbing) layer 602, a second (e.g., outer shell) layer 604, and a reactive layer 605.

[0214] The reactive layer 605 shown in Figure 6A is formed from a plurality of spheres 606 and a gel structure 614 in which the spheres 606 are embedded. The spheres 606 are smaller than those seen in previous figures, such that there are multiple spheres 606 disposed throughout the gel structure 104. It will be understood that a variety of different sizes of spheres 606 are within the scope of this embodiment.

[0215] Sphere 606 is suspended in gel structure 614. By suspending sphere 606 in gel structure 614, sphere 606 is held in a fixed arrangement between first layer 602 and second layer 604. However, sphere 606 may maintain freedom of movement within gel structure 614, for example, due to the flexibility of the gel.

[0216] When the shock absorbing structure is subjected to an impact above a certain threshold force, the gel structure 614 ruptures or collapses, allowing the spheres 606 to be released from their fixed positions within the reactive layer. The spheres 606 can then move from their previous fixed positions.

[0217] In some embodiments, instead of the gel structure 614, the reactive layer 605 can comprise an adhesive or flexible liner (e.g., plastic packaging) that holds the spheres 606 in a fixed arrangement between the first layer 602 and the second layer 604.

[0218] Figure 6B shows a shock mitigating structure 650 similar to that seen in Figure 6A. The shock mitigating structure 650 comprises a first layer 652 and a reactive layer 605 formed from a plurality of spheres 656 and a gel structure 664. However, the shock mitigating structure 650 does not comprise an outer layer.

[0219] When the shock mitigating structure is impacted by the reactive layer 605, the gel structure 614 will rupture or collapse such that the sphere 656 is released and pushed out of the shock mitigating structure 650. The sphere 656 can then move away from the shock mitigating structure 650, taking with it some of the energy that was applied to the structure 650 during the impact.

[0220] It will also be appreciated that in the embodiments previously described herein, some of the structures and features for holding the discrete elements in a particular arrangement (e.g., the connectors in FIG. 5) are also suitable for embodiments in which the shock mitigating structure includes a first layer and a reactive layer, but no second layer, and embodiments having any suitable combination of such features may also be provided.

[0221] 7 is a schematic diagram of a portion of an impact mitigating structure 700 according to an embodiment of the present invention. The impact mitigating structure 700 is formed from a reactive layer 705 disposed between an expanded polystyrene layer 702 having a polycarbonate coating and a polycarbonate outer shell 704. The reactive layer 705 may be provided in any suitable and desired arrangement, for example, as shown in any one (or combination) of FIGS. 1-6B.

[0222] Figures 1-7 show embodiments of a shock mitigating structure comprising primarily a first layer, a second layer, and a reactive layer. In the embodiments shown in Figures 8-10, the shock mitigating structure comprises an additional layer. Again, in these figures, the reactive layer may be provided in any suitable and desired arrangement, for example, as shown in any one (or combination) of Figures 1-6B.

[0223] 8, the impact mitigating structure 800 includes a first layer 802 and a second layer 804. The first layer 802 and the second layer 804 are both energy absorbing layers, and are arranged to absorb energy imparted by, for example, an impact. A reactive layer 805 is arranged between the impact absorbing layers 802, 804. The first layer 802 and / or the second layer 804 may have a hard (e.g., polycarbonate) coating on their surface in contact with the reactive layer 805. The impact mitigating structure 800 further includes a hard outer layer 812, for example, bonded to the second layer 804.

[0224] When the impact mitigating structure 800 is impacted, the hard outer layer 812 remains in position on the second layer 804, while the first layer 802 and second layer 804 can move relative to each other. In other embodiments, the hard outer layer 812 can be pushed away from the second layer 804 upon impact.

[0225] 9, the impact mitigation structure 900 includes a first layer 902 that is a cellular (e.g., honeycomb) structure with a plurality of tessellating cells. The impact mitigation structure 900 also includes a second layer 904, formed of, for example, expanded polystyrene, which functions as a shock absorbing layer. A reactive layer 905 is positioned between these two layers. Both the first layer 902 of the cellular structure and the expanded polystyrene layer 904 may include a hard (e.g., polycarbonate) coating on their surface that contacts the reactive layer 905. A polycarbonate shell 912 is disposed on the exterior of the second layer 904.

[0226] 10, the impact mitigating structure 1000 comprises a first polycarbonate layer 1002 and a second polycarbonate layer 1004. A reactive layer 1005 is located between the polycarbonate layers 1002, 1004. The impact mitigating structure 1000 further comprises an impact absorbing layer 1016 (e.g., an expanded polystyrene layer or a cellular structure having a plurality of tessellated cells) located below the polycarbonate layers 1002, 1004 and the reactive layer 1005.

[0227] The cellular structures 902, 1016 (if present) may be arranged to provide protection against forces resulting from an impact (eg, functioning as a shock absorbing structure).

[0228] 11 and 12 show the behavior of the impact mitigating structure during and / or after an impact above a certain threshold force.

[0229] Figure 11 is a diagram illustrating the shock absorbing structure 100 seen in Figure 1. When an impact is applied to the outer second layer 104, the energy from the impact is transferred to the first layer 102, the second layer 104, and the reactive layer 105. The force of the impact disrupts the alignment of the spheres 106 in the reactive layer 105. The spheres 106 can then rotate and roll due to the increased degrees of freedom, as shown by the arrows in Figure 11.

[0230] The rotation and rolling of the spheres 106 helps the first layer 102 and the second layer 104 slide and move relative to each other. As shown by the arrows indicating the direction of movement in FIG. 11, the first layer 102 and the second layer 104 move in different directions relative to each other. This results in well-controlled movement of the first layer 102 and the second layer 104 relative to each other. For example, the first layer 102 and the second layer 104 can move relative to each other over a distance of 40 mm to 50 mm, depending on the magnitude of the impact.

[0231] It will be appreciated that the movement of the first layer 102 and the second layer 104 relative to one another due to the turbulence and movement of the spheres 106 within the reactive layer 105 helps to remove some of the energy from the impact, particularly in an oblique impact on the second layer 104. This helps to reduce the energy from the impact that is transmitted to other parts (remaining parts) of the impact mitigation structure 100, and helps to reduce the effect of the impact on, for example, a body protected by the impact mitigation structure 100.

[0232] FIG. 12 illustrates an impact mitigation structure formed from a first layer 1202 and a reactive layer 1205. The discrete elements 1206 of the reactive layer 1205 are held in a particular arrangement by a flexible material (e.g., similar to the arrangement shown in FIGS. 6A and 6B ). Alternatively, the discrete elements can be held in a particular arrangement using connectors (e.g., similar to the arrangement shown in FIG. 3 ). Upon impact with a force above a certain threshold force, the discrete elements 1206 begin to rotate, breaking from the rest of the reactive layer 1205 and releasing from the first layer 1202. The discrete elements 1206 transfer energy from the impact away from the first layer 1202, thereby reducing energy transfer to the first layer and, for example, a person or object wearing the impact mitigation structure.

[0233] Figure 13 shows a schematic of a portion of an impact mitigating structure 1300 in which elements 1306 of a reactive layer 1305 located between a first inner layer 1302 and a second outer layer 1304 are connected together by a series of connectors 1307. As shown in Figure 13, the elements 1306 are connected together by linear strings. Embodiments are envisioned in which the elements 1306 are connected together in two-dimensional or three-dimensional arrays.

[0234] FIG. 14 schematically illustrates how connections 1407, 1408, 1409 between elements 1406 of a reactive layer may be arranged relative to a shock absorbing layer 1416, for example, with a shell layer 1402. Connections 1407 may be rigid and brittle, so as to break apart upon impact. Connections 1408 may be springy or elastic, so as to stretch upon impact and, for example, return to their original state thereafter. Connections 1409 may be slack, so as to tighten upon impact. Thus, it will be appreciated that when a shock mitigating structure containing a reactive layer having elements connected together by connections is impacted, the connections will be disrupted (e.g., stretched, broken, or tightened) to allow movement of the elements, thereby facilitating movement of the layers of the shock mitigating structure relative to one another.

[0235] 15 shows schematically how connections 1507 between elements 1506 of a reactive layer may be connected to a shock absorbing layer 1516 with a shell layer 1502. As shown, the connections 1507 between elements 1506 pass through the shock absorbing layer 1516 and the shell layer 1502, forming a string between the elements 1506 and the connections 1507. In operation, the connections 1507 may release from the shock absorbing layer 1516 and the shell layer 1502 and / or break themselves to allow movement of the elements 1506, thereby facilitating movement of the layers of the shock mitigating structure relative to one another.

[0236] 16 schematically illustrates elements 1606 individually connected to a shock absorbing layer 1616 with a shell layer 1602, for example, via spring-loaded connections 1607. As shown, the connections 1607 between the elements 1606 pass through the shock absorbing layer 1616 and the shell layer 1602. In operation, the connections 1607 may stretch and / or release from the shock absorbing layer 1616 and the shell layer 1602 and / or break to allow movement of the elements 1606, thereby facilitating movement of the layers of the shock mitigating structure relative to one another.

[0237] 17 shows a schematic representation of an impact mitigating structure 1700 having a reactive layer 1705 between an outer layer 1704 and a shell layer 1702 covering an energy absorbing layer 1716. In the reactive layer 1705, the elements 1706 are cylindrical. Upon impact to the impact mitigating structure 1700, which causes the elements 1706 of the reactive layer 1705 to roll (thus promoting movement of the outer layer 1704 and the shell layer 1702 relative to one another), the cylindrical elements 1706 will preferentially roll in a direction perpendicular to their axis of symmetry.

[0238] 18 is a diagram showing the rolling of cylindrical elements 1806 of the reaction layer when an impact is applied to the shock-absorbing structure. As shown in the figure, the cylindrical elements 1806 roll in a direction perpendicular to their symmetry axes.

[0239] FIG. 19 shows schematically that, for example, cylindrical elements 1906 of the reaction layer can be connected together by (e.g., string-like) connectors 1907 in a manner similar to the elements of the reaction layer shown in FIG. 13.

[0240] FIG. 20 shows schematically that in a manner similar to the elements of the reaction layer shown in FIG. 15, for example, cylindrical elements 2006 of the reaction layer may be connected together by (e.g., string-like) connectors 2007 that pass through the shock absorbing layer 1516 and the shell layer 1502 of the shock mitigating structure.

[0241] FIG. 21 schematically illustrates a shock mitigating structure 2100 having a reactive layer 2105 between an outer layer 2104 and a shell layer 2102 that covers an energy absorbing layer 2116. Similar to the shock mitigating structure shown in FIG. 17, in the reactive layer 2105, the elements 2106 are cylindrical. However, as shown in FIG. 21, the cylindrical elements 2106 are arranged with their axes not all aligned with one another. Thus, when the shock mitigating structure 2100 is subjected to an impact that causes the elements 2106 of the reactive layer 2105 to roll (thus promoting movement of the outer layer 2104 and shell layer 2102 relative to one another), the cylindrical elements 2106 roll in multiple different directions. This helps to control friction between the outer layer 2104 and shell layer 2102 as they move relative to one another.

[0242] 22 shows a schematic cross-section through an impact mitigating structure 2200. The impact mitigating structure 2200 includes a shell layer 2202 covering an energy absorbing layer 2216, and a reactive layer 2205 between the outer layer 2204 and the shell layer 2202. The outer layer 2204 includes multiple undulations such that it has outwardly protruding portions and inwardly protruding recesses. Thus, the spacing between the outer layer 2204 and the shell layer 2202 varies throughout the reactive layer 2205. To accommodate the varying spacing between the outer layer 2204 and the shell layer 2202, the elements 2206, 2207 of the reactive layer 2205 have multiple different sizes that correspond to the spacing between the outer layer 2204 and the shell layer 2202. For example, reactive layer 2205 includes larger elements 2206 when the spacing between outer layer 2204 and shell layer 2202 is greater, and includes smaller elements 2207 when the spacing between outer layer 2204 and shell layer 2202 is smaller.

[0243] 23 shows a schematic cross-section through a shock mitigating structure 2300. The shock mitigating structure 2300 has a shell layer 2302 covering an energy absorbing layer 2316, and a reaction layer 2305 between the outer layer 2304 and the shell layer 2302. The reaction layer 2305 includes a housing 2307 for one or more rolling elements 2306. The housing 2307 partially encases the rolling elements 2306 such that a portion of the rolling elements 2306 is exposed. In operation, when the shock mitigating structure 2300 is impacted, the exposed portion of the rolling elements 2306 contacts the outer layer 2304, facilitating movement of the outer layer 2304 relative to the shell layer 2302 due to rolling of the elements 2306 within the housing 2307.

[0244] 24A and 24B show schematic cross-sections through a shock mitigating structure 2400. The shock mitigating structure 2400 has a shell layer 2402 covering an energy absorbing layer 2416, and a reactive layer 2405 between the outer layer 2404 and the shell layer 2402. In the reactive layer 2405, an element 2406 is held in place (during normal use) between the shell layer 2402 and the outer layer 2404 by a patch of adhesive 2407. In operation, when the shock mitigating structure 2400 is impacted (as shown in FIG. 24B ), the element 2406 is released by rolling (e.g., peeling) away from the patch of adhesive 2407, allowing it to roll freely, thus facilitating movement of the outer layer 2404 relative to the shell layer 2402.

[0245] 25 schematically shows a cross section through a shock mitigating structure 2500. The shock mitigating structure 2500 has a reactive layer 2505 between an outer layer 2504 and an inner layer 2502. The reactive layer 2505 has rolling elements 2506. One or more (e.g., all) of the inner layer 2502, the outer layer 2504, and the rolling elements 2506 have high friction surfaces. In operation, when the shock mitigating structure 2500 is impacted, friction between the elements 2506 and one or both of the inner layer 2502 and the outer layer 2504 creates a torque that causes the elements 2506 to roll, thus promoting movement of the outer layer 2504 relative to the inner layer 2502.

[0246] 26 shows a schematic cross-section through a shock mitigating structure 2600. The shock mitigating structure 2600 includes a reactive layer 2605 between an outer layer 2604 and an inner layer 2602. The reactive layer 2605 includes rolling elements 2606. The inner layer 2602, the outer layer 2604, and the rolling elements 2606 each have interlocking notches formed in their surfaces. In operation, when the shock mitigating structure 2600 is impacted, the interlocking notches between the elements 2606, the inner layer 2602, and the outer layer 2604 act like teeth and pinion gears, creating a torque that causes the elements 2606 to roll, thereby facilitating movement of the outer layer 2604 relative to the inner layer 2602.

[0247] Figure 27 shows a schematic cross section through an impact absorbing structure 2700. The impact absorbing structure 2700 is similar to that shown in Figure 10 in that it includes two thin layers 2702, 2704 on either side of a plurality of rolling elements 2706 of a reactive layer, and further includes a thicker inner impact absorbing layer 2716. The thin layers 2702, 2704 (e.g. made of polycarbonate) are harder than the inner impact absorbing layer 2716 (e.g. made of EPS).

[0248] The reactive layer also includes a flexible (e.g., fiber) layer 2711 that is bonded to the thin layer 2702 adjacent to the shock absorbing layer 2716. The flexible layer 2711 holds the plurality of rolling elements 2706 in place within the reactive layer, maintaining the plurality of rolling elements 2706 between the flexible layer 2711 and the thin layer 2702 upon impact.

[0249] Figure 28 shows a schematic cross-section through a shock absorbing structure 2800. The shock absorbing structure 2800 is similar to that shown in Figure 27 in that it includes a flexible layer 2811 that supports a plurality of rolling elements 2806 of the reactive layer. In this shock absorbing structure 2800, the flexible layer 2811 is the outermost layer of the shock absorbing structure 2800 and does not include an additional outer layer (e.g., a rigid layer). The flexible layer 2811 is bonded directly to the shock absorbing layer 2816 rather than to any intermediate (rigid) thin layer, which is not shown in this embodiment.

[0250] Figure 29 shows a schematic cross-section through a shock mitigating structure 2900. The shock mitigating structure 2900 is similar to that shown in Figure 28 in that it has similar components: a shock absorbing layer 2916, a flexible layer 2911, and a plurality of rolling elements 2906 of a reactive layer held between the shock absorbing layer 2916 and the flexible layer 2911. However, in the embodiment shown in Figure 29, the order of the layers is reversed, with the flexible layer 2911 being the innermost layer (e.g., positioned adjacent the head of a wearer of a helmet incorporating the shock mitigating structure 2900) and the shock absorbing layer 2916 on the outside.

[0251] Figures 30A and 30B are schematic diagrams of a shock mitigating structure 3000, with Figure 30A being a partially exploded view. The shock mitigating structure 3000 is similar to that shown in Figure 27 in that it includes a shock absorbing layer 3016, an outer (hard and thin) layer 3004, and an intermediate reactive layer including a plurality of rolling elements 3006 maintained by a flexible layer 3011.

[0252] The flexible layer 3011 is attached to the shock absorbing layer 3016 by interconnecting notches 3013 in the shock absorbing layer 3016 and the reactive layer.

[0253] Figure 31 shows a schematic cross section through an impact absorbing structure 3100. The impact absorbing structure 3100 is similar to that shown in Figure 27 in that it comprises two thin layers 3102, 3104 on either side of a plurality of rolling elements 3106 of a reactive layer, and further comprises a thicker inner impact absorbing layer 3116. The thin layers 3102, 3104 (e.g. made of polycarbonate) are harder than the inner impact absorbing layer 3116 (e.g. made of EPS).

[0254] The reactive layer also includes a flexible (e.g., fiber) layer 3111 that surrounds and encapsulates the plurality of rolling elements 3106. The flexible layer 3111 holds the plurality of rolling elements 3106 in place within the reactive layer and maintains the plurality of rolling elements 3106 within the flexible layer 3111 upon impact.

[0255] Figures 32A and 32B show schematic cross-sectional views through a shock mitigating structure 3200. The shock mitigating structure 3200 is similar to that shown in Figure 31 in that it includes a flexible (e.g., textile) layer 3211 that surrounds and encapsulates a plurality of rolling elements 3206 of a reactive layer.

[0256] The flexible layer 3211 is attached (e.g., with an adhesive) on either side to the thin outer layer 3204 and the inner shock absorbing layer 3216. The flexible layer 3211 has a plurality of hinge lines 3213 where the two sides of the flexible layer 3211 are attached to each other, which separates the plurality of rolling elements 3206 into a plurality of discrete portions of the reactive layer.

[0257] 32B shows the behavior when the shock absorbing structure 3200 is subjected to an impact with a tangential component (component parallel to the plane of the outer layer 3204). In the first stage of the impact, the outer layer 3204 is displaced relative to the inner shock absorbing layer 3216. Because the flexible layer 3211 is attached to the outer layer 3204 and the inner shock absorbing layer 3216, the flexible layer 3211 deforms and stretches but does not rupture.

[0258] This impact also causes the outer layer 3204 and the inner shock absorbing layer 3216 to contact the rolling elements 3206 through the respective sides of the flexible layer 3211. This causes the rolling elements 3206 to roll due to friction between the contact points of the outer layer 3204, the flexible layer 3211, the inner shock absorbing layer 3216, and the rolling elements 3206. This promotes movement of the outer layer 3204 relative to the inner shock absorbing layer 3216.

[0259] During displacement of the outer layer 3204 relative to the inner shock absorbing layer 3216, the hinge lines 3213 of the flexible layer 3211 allow the reactive layer to flex so that the reactive layer can accommodate this displacement, especially when the outer layer 3204 and the inner shock absorbing layer 3216 have double curved surfaces.

[0260] If the impact has a force less than a certain threshold force, the outer layer 3204 remains attached to the flexible layer 3211. After the impact, the flexible layer 3211, and therefore the outer layer 3204, return to their original positions. If the impact has a force greater than a certain threshold force, the outer layer 3204 delaminates from the flexible layer 3211 and separates from the rest of the impact mitigating structure 3200. The release of the outer layer 3204 from the flexible layer 3211 allows the flexible layer 3211 to return to its original position while maintaining the plurality of rolling elements 3206.

[0261] Figures 33A and 33B show schematic cross-sectional views through a shock absorbing structure 3300. The shock absorbing structure 3300 is similar to that shown in Figures 32A and 32B in that it includes a flexible (e.g., fibrous) layer 3311 that surrounds and encapsulates a plurality of rolling elements 3306 of the reactive layer between a thin outer layer 3304 and an inner shock absorbing layer 3316. A plurality of struts 3315 connect the thin outer layer 3304 and the inner shock absorbing layer 3316.

[0262] The struts 3315 pass through the flexible layer 3311, dividing the reactive layer into a plurality of discrete sections, each containing a plurality of rolling elements 3306. The struts 3315 are positioned such that they pivot (e.g., at their points of attachment to the outer layer 3304 and inner shock absorbing layer 3316) when the shock mitigating structure 3300 is subjected to an impact that displaces the outer layer 3304 relative to the inner shock absorbing layer 3316.

[0263] The pivoting of the struts 3315 helps to allow the reactive layer to move between the (e.g., double-curved) surfaces of the outer layer 3304 and the inner shock absorbing layer 3316 when the outer layer 3304 is displaced relative to the inner shock absorbing layer 3316, as shown in FIG. 33B.

[0264] Figure 34 shows a schematic cross section through a shock mitigating structure 3400. The shock mitigating structure 3400 is similar to that shown in Figures 32A and 32B in that it includes a flexible (e.g., textile) layer 3411 between a thin outer layer 3404 and an inner shock absorbing layer 3416 that surrounds and encapsulates a plurality of rolling elements 3406 of the reactive layer.

[0265] The flexible layer 3411 has a plurality of hinge lines 3413 where the two sides of the flexible layer 3411 are attached to each other, thereby separating the plurality of rolling elements 3406 into a plurality of discrete portions of the reactive layer. The hinge lines 3413 are formed by crimping the flexible layer 3411 in a spring-like manner, thereby allowing the reactive layer to flex as well as stretch when the impact mitigating structure 3400 is impacted, which again helps to conform to the moving surfaces of the outer layer 3404 and inner impact absorbing layer 3416.

[0266] Figures 35A and 35B show schematic cross-sections through a shock mitigating structure 3500. The shock mitigating structure 3500 is similar to that shown in Figure 7 in that it comprises a thin outer layer 3504 and an inner shock absorbing layer 3516 with a plurality of rolling elements 3506 of a reactive layer disposed therebetween.

[0267] The outer layer 3504 and the inner shock absorbing layer 3516 are attached to each other around their respective peripheries by compressible foam tape 3515. In operation, as shown in Fig. 35B, when the impact mitigating structure 3500 is impacted, the impact causes the compressible foam tape 3515 to compress so that the outer layer 3504 and the inner shock absorbing layer 3516 contact the respective sides of the plurality of rolling elements 3506. This contact of the outer layer 3504 and the inner shock absorbing layer 3516 with the plurality of rolling elements 3506 causes the plurality of rolling elements 3506 to roll, thereby facilitating movement of the outer layer 3504 and the inner shock absorbing layer 3516 relative to each other.

[0268] The compressible foam tape 3515 prevents the outer layer 3504 and the inner shock absorbing layer 3516 from contacting each other, thereby reducing friction between the outer layer 3504 and the inner shock absorbing layer 3516 and helping to prevent geometric locking between the outer layer 3504 and the inner shock absorbing layer 3516.

[0269] Figure 36 shows a schematic exploded view of a shock absorbing structure 3600. The shock absorbing structure 3600 is similar to that shown in Figure 31 in that it includes two thin layers 3602, 3604 on either side of a plurality of rolling elements 3606 in a reactive layer, and further includes a thicker inner shock absorbing layer 3616. The thin layers 3602, 3604 (e.g., made of polycarbonate) are harder than the inner shock absorbing layer 3616 (e.g., made of EPS).

[0270] The reactive layer also includes flexible (e.g., fiber) layers 3611 a, 3611 b that surround and encapsulate the plurality of rolling elements 3606. The flexible layers 3611 a, 3611 b hold the plurality of rolling elements 3606 in place within the reactive layer and maintain the plurality of rolling elements 3606 within the flexible layers 3611 a, 3611 b upon impact.

[0271] The flexible layers 3611 a, 3611 b are formed from an upper flexible layer 3611 a and a lower flexible layer 3611 b. When the impact mitigating structure 3600 is assembled, for example, by heat pressing the upper and lower flexible layers 3611 a, 3611 b together at different hinge lines, the plurality of rolling elements 3606 are separated into discrete portions, for example, as shown in Figures 32A and 32B.

[0272] Figure 37 shows a schematic exploded view of a shock absorbing structure 3700. The shock absorbing structure 3700 is similar to that shown in Figure 27 in that it includes two thin layers 3702, 3704 on either side of a plurality of rolling elements 3706 in a reactive layer, and further includes a thicker inner shock absorbing layer 3716. The thin layers 3702, 3704 (e.g., made of polycarbonate) are harder than the inner shock absorbing layer 3716 (e.g., made of EPS).

[0273] The reactive layer also includes a flexible (e.g., fiber) layer 3700 that is bonded to a thin layer 3702 adjacent to an impact absorbing layer 3716. The flexible layer 3711 holds the plurality of rolling elements 3706 in place within the reactive layer, maintaining the plurality of rolling elements 3706 between the flexible layer 3711 and the thin layer 3702 upon impact.

[0274] When the impact mitigating structure 3600 is assembled, an adhesive layer 3171 is coated on the inner thin layer 3702 such that the flexible layer 3711 is bonded to the thin layer 3702. Furthermore, to distribute the plurality of rolling elements 3706 on the thin layer 3702, the plurality of rolling elements 3706 are cut into discrete portions, for example as shown in Figures 32A and 32B.

[0275] The two thin layers 3702, 3704 are connected to each other by heat pressing at a line 3719 at the periphery of each of the two thin layers 3702, 3704.

[0276] Figures 38 and 39 illustrate how the impact mitigating structures of the present invention may be formed into helmets 3800, 3900. In helmet 3800 shown in Figure 38, an outer (e.g., shell and / or impact absorbing) layer 3804 and an inner cellular structure 3802 can be seen. A reactive layer, not shown for clarity, is disposed between first (inner cellular structure) layer 3802 and second (outer) layer 3804. The reactive layer may be provided in any suitable and desired arrangement, for example, as shown in any one (or combination) of Figures 1-37, although it will be understood that the various layers may be provided in a curved configuration to provide the shape of helmet 3800.

[0277] In FIG. 39, helmet 3900 includes a first (inner, impact-absorbing) layer 3202 formed from expanded polystyrene substantially covered by a second (outer shell) layer 3904 formed from hard polycarbonate. The first (inner, impact-absorbing) layer 3902 may also include a hard coating on a surface that contacts the reactive layer. The reactive layer, not shown for clarity, is disposed between first (inner) layer 3902 and second (outer) layer 3904. The reactive layers may be provided in any suitable and desired arrangement, for example, as shown in any one (or combination) of FIGS. 1-37, although it will be understood that the various layers may be provided in a curved configuration to provide the shape of helmet 3900.

[0278] Thus, one skilled in the art will appreciate that an impact mitigating structure according to an embodiment of the present invention, in which multiple elements are disorganized upon impact to promote movement of the first and second layers relative to one another, can help reduce forces transmitted through the impact mitigating structure, for example, to a user or object that it protects. This provides an advantage over known impact mitigating structures, and particularly when the impact mitigating structure is a helmet, can provide a significant advantage over known helmets, and can help reduce brain injuries, for example.

[0279] However, it will be further understood that many variations of the specific arrangements described herein are possible within the scope of the present invention. For example, while the cross-sections shown in the drawings, which are schematic representations of embodiments of the present invention, show flat layers of the shock mitigating structure (for clarity), it will be understood that in at least preferred embodiments, these layers of the shock mitigating structure are curved (e.g., doubly).

Claims

1. 1. A helmet comprising an impact mitigation structure, the impact mitigation structure comprising: a first inner layer; a second outer layer; and a reactive layer disposed between the first inner layer and the second outer layer, the reactive layer comprising a plurality of elements held between the first inner layer and the second outer layer; Equipped with the reactive layer is arranged such that, when the second outer layer is impacted, a plurality of elements of the reactive layer are configured to roll to promote movement of the first inner layer and the second outer layer relative to one another; The first inner layer and the second outer layer are arranged to completely separate upon impact. Said helmet.

2. The helmet according to claim 1 , wherein the reaction layer is arranged to allow the plurality of elements to roll when the impact mitigation structure is subjected to an impact having at least a particular force.

3. The helmet according to any one of claims 1 to 2, wherein the reaction layer is configured such that when the impact absorbing structure is subjected to an impact, the plurality of elements are released by the impact and the plurality of elements move freely in three dimensions.

4. The helmet according to claim 2, wherein the specific force is between 10N and 100N, for example between 30N and 70N, for example about 50N.

5. the plurality of elements being held in a specific arrangement between the first inner layer and the second outer layer; When the impact absorbing structure is impacted, at least some of the elements are released from the specific arrangement; and the released element is configured to facilitate movement of the first inner layer and the second outer layer relative to one another. A helmet according to any one of claims 1 to 4.

6. The helmet according to any one of claims 1 to 5, wherein the number of elements in the plurality of elements is between 5 and 100,000, for example between 50 and 10,000, for example between 100 and 1,000.

7. 7. A helmet according to any one of claims 1 to 6, wherein the ratio of the surface area of ​​the reaction layer on which the elements are provided to the surface area of ​​the reaction layer is between 0.05 and 0.5, for example between 0.1 and 0.4, for example about 0.

25.

8. The helmet according to any one of claims 1 to 7, wherein the plurality of elements have a size greater than a quarter of the thickness of the reaction layer.

9. A helmet according to any one of the preceding claims, wherein the elements are made from a material having a Shore A hardness of more than 50, for example more than 100.

10. 10. A helmet as described in any one of claims 1 to 9, wherein one or more of the plurality of elements, the first layer, and the second layer are provided with a material or coating such that the plurality of elements are configured to contact one or both of the first inner layer and the second outer layer when the impact mitigation structure is impacted, thereby causing the material or coating to roll the plurality of elements and promoting movement of the first inner layer and the second outer layer relative to each other.

11. The helmet according to any one of claims 1 to 10, wherein the hardness of the elements is greater than the hardness of the first layer and / or the second layer.

12. 12. The helmet of claim 1, wherein the plurality of elements are held in a specific arrangement between the first layer and the second layer, and the specific arrangement of the plurality of elements of the reaction layer is configured to be disturbed to promote movement of the first inner layer and the second outer layer relative to each other when the second layer is subjected to an impact.

13. 13. The helmet of claim 12, wherein the impact mitigation structure comprises a support structure arranged to hold the elements in the particular arrangement and to release the elements when the impact mitigation structure is subjected to an impact.

14. 14. The helmet according to any one of claims 1 to 13, wherein the surface of the first layer and / or the second layer between which the reaction layer is arranged is provided with a hard coating or layer having the same hardness as the elements and / or a higher hardness than the hardness of the first layer and / or the second layer on which the coating or layer is provided.

15. the impact absorbing structure includes a retaining structure disposed to retain the plurality of elements between the first layer and the second layer; the retaining structure is arranged to retain the elements when the impact absorbing structure is subjected to an impact. A helmet according to any one of claims 1 to 14.

16. 16. The helmet of claim 15, wherein the retention structure substantially completely encloses and / or surrounds the plurality of elements.

17. 17. A helmet according to claim 15 or 16, wherein the retention structure comprises a flexible layer at least partially encapsulating and / or surrounding the elements.

18. 18. The helmet of claim 17, wherein the flexible layer is arranged to stretch when the impact mitigating structure receives an impact.

19. 19. A helmet as claimed in claim 17 or 18, wherein the flexible layer is arranged to prevent the impact mitigating structure from tearing, breaking, rupturing and / or being destroyed upon impact.

20. 20. The helmet of claim 17, 18 or 19, wherein the flexible layer is attached to the first inner layer and / or the second outer layer by an adhesive.

21. 21. The helmet of any one of claims 1 to 20, wherein the first layer and the second layer are attached to one another by one or more struts and / or one or more spacers extending between the first layer and the second layer.

22. 22. The helmet of claim 21, wherein the one or more struts and / or the one or more spacers are compressible and configured to compress when the crash mitigation structure is subjected to an impact.

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