PROTECTION HELMET

DESCRIPTION

This invention relates in general to the technical field of protection helmets, for example protection helmets for motorcycling. More specifically, the invention relates to an energy absorption layer, and a protection helmet comprising said energy absorption layer. The energy absorption layer is designed to be interposed between an outer shell of the helmet and the head of a user, in order to protect the latter from collisions and impacts.

In the field of protection helmets, the use of an energy absorption layer is known, the layer being interposed between the outer shell, having the function of protection against penetration, and the head of a user. This layer has the purpose of protecting the head of the user in the event of a collision or impact, for example following a fall.

This layer is therefore made of a material capable of absorbing energy due to a collision or impact. In this way the layer can at least partially absorb the kinetic energy of the collision or impact, in order to avoid sudden decelerations of the head. Generally, this layer is made of polystyrene, in particular expanded polystyrene or polystyrene, as it is a very economical and light material which allows an excellent absorption of collision or impact energy to be obtained.

A polystyrene layer according to the prior art is present along most of the inner surface of the helmet crown, and for this reason it can also comprise air passage channels, so as to favour aeration near the head of the user.

This solution, while advantageous from many points of view, has some drawbacks.

In particular, the traditional moulding technology of the polystyrene layer, in fact, poses some significant limitations. Firstly, the coating according to the prior art creates a resistance to collisions or impacts both along a radial direction, or coming out from the head of a user, and along a direction perpendicular to the latter, for example a direction tangential to the head of the user. This results in a transmission of rotational forces to the head of the user, particularly in the event of an impact tangential to the outer surface of the helmet, which can cause injury to the user following a rotation of the head caused by the impact itself.

In fact, a layer according to the prior art is generally made by means of a single block of polystyrene which cannot be made according to complex geometries and is more suitable for absorbing impact energy in a more precise and/or complete way.

Furthermore, a traditional layer has structural limitations linked to the geometry of the aeration channels, since the latter can only be made in simple and standardised shapes, for example in a cylindrical shape. The geometry of these channels is, in fact, limited to the movement of a carriage inside the mould wherein the polystyrene element is produced, preventing the creation of complex geometries. This prevents the creation of a coating that allows an improved level of aeration of the head of a user wearing the helmet.

The invention starts from the technical problem of providing an energy absorption layer and a helmet provided with such an energy absorption layer which makes it possible to satisfy the above-mentioned needs with reference to the prior art, and to overcome the above-mentioned drawback and/or to allow further advantages to be achieved.

This is achieved by means of an energy absorption layer and a helmet as defined in the respective independent claims. Secondary characteristics are covered by the respective dependent claims.

In particular, the object of the invention is an energy absorption layer for a protection helmet intended to perform an energy absorption function in the event of a collision or impact, wherein said energy absorption layer is curved to define a convex side, corresponding to an outer side, and a concave side corresponding to an inner side defining a concavity-side zone corresponding to an inner cavity of the helmet, which in the helmet is designed to accommodate the head of an individual.

A radial direction is a direction orthogonal to, or incident with, the convex side of the energy absorption layer directed towards a central zone, or center, of the concavity-side zone.

According to an aspect of the invention, the energy absorption layer comprises a plurality of energy absorption bodies arranged in a respective radial direction and a monolithic support structure, that is, a structure made in one piece, or as a single piece, suitable to support the energy absorption bodies. More specifically, the energy absorption bodies are spaced in relation to each other and portions of said monolithic support structure are interposed in a region comprised between adjacent energy absorption bodies; moreover each of said energy absorption bodies is kept in position by said monolithic support structure and, in said position, configured to absorb mechanical energy in the respective radial direction.

The adjective “monolithic” means a structure, or other assembly, which is made of one piece in a single body, that is, in other words, a monobloc, which can have a configuration such as to laterally support the energy absorption bodies.

The energy absorption layer therefore has a plurality of energy absorption bodies, which have the sole function of energy absorption, and a monolithic support structure which has a different function from the energy absorption, support and lateral support bodies of the energy absorption bodies.

The above-mentioned technical problem is also solved by a helmet comprising:

- an outer shell having a penetration protection function, and

- an energy absorption layer associated with the outer shell.

Preferably, the helmet also includes an inner padding having a comfort function, and the energy absorption layer is interposed between the outer shell and the inner padding.

The term “outer shell” refers to the layer most exposed to view, usually made of composite fibre with a thermosetting matrix or of thermoplastic material, of a protection helmet. As mentioned above, there may be an inner padding having a comfort function. The term "padding" refers to any inner lining, preferably for comfort, of the helmet designed to be placed in contact with the head of a user.

The helmet has the above-mentioned inner cavity designed to accommodate the head of an individual. For the geometry of the parts described above, since the energy absorption layer is placed on the inner side of the shell, in said helmet, the above-mentioned radial direction is a direction orthogonal to the outer shell and/or a direction extending between the outer shell and the inner cavity. A tangential direction is a point tangential direction at a surface of the inner cavity of the helmet, or of the outer shell. A tangential direction is a direction transversal to the radial direction. Ideally, the surface of the inner cavity could be thought of as a surface generated by the rotation of the head within the cavity.

The tangential direction is therefore in fact a direction transversal to a radial direction. Therefore, both in the energy absorption layer and in the helmet, a plurality of radial directions and a plurality of tangential or transversal directions can be identified.

The energy absorption layer comprises, as mentioned, the plurality of energy absorption bodies distributed at a mutual distance and arranged along respective radial directions locally orthogonal to the surface of the head of a user. In general, the monolithic support structure is preferably a structure which yields in said tangential direction and/or each portion of the monolithic support structure is preferably configured to be subjected to deformation in the event of a collision or impact in one or more tangential directions.

In practice, as mentioned above, at the basis of the invention is the consideration of the energy absorption layer as a layer wherein there are bodies or structures or portions which act as energy absorption in the radial direction, and that these bodies are supported laterally by a monolithic support structure, so as to create a combined effect between the monolithic support structure and energy absorption bodies. In this way, if a lateral or tangential impact occurs, there is no direct transmission of rotational impact energy between the outer shell and the inner cavity of the helmet. In fact, as the energy absorption bodies being separated from each other, they are unstable and substantially undergo a slight bending or folding in a tangential or lateral direction, and this movement they are only slightly obstructed by the monolithic support structure, which preferably yields.

According to an embodiment, the monolithic support structure is a structure which is obtained according to a gyroid modelling scheme such as to allow a certain yield; other modelling schemes can be chosen to form the monolithic support structure. The structure can be modelled in such a way as to form empty channels where the energy absorption bodies are received as one piece or as detached pieces.

The term "energy absorption bodies" means "structures" or "substructures" suitable for energy absorption and which are distinguishable among the plurality of lattice structures of the lattice.

Preferably, the above-mentioned monolithic support structure is a monolithic lattice, that is to say a lattice made in one piece, or in a single piece, or in other words still a porous monobloc.

According to a preferred aspect of the invention, the energy absorption bodies are spaced in relation to each other and embedded in the monolithic lattice, so as to define a plurality of lattice structures of the monolithic lattice. In practice, the monolithic support structure is a monolithic lattice and the energy absorption bodies are incorporated and distributed in the monolithic lattice. Said energy absorption bodies are spaced in relation to each other and consequently each portion of the monolithic support structure is a lattice structure of the monolithic lattice interposed in a region comprised between adjacent energy absorption bodies.

Each lattice structure is therefore part of a monolithic lattice and arranged in the region between adjacent energy absorption bodies. Each of said energy absorption bodies is configured to absorb mechanical energy in the respective radial direction and to become unstable in the tangential direction so as to limit the generation of tangential forces.

Each lattice structure advantageously yields sufficiently in the tangential direction in the event of an impact, that is to say, it is configured to yield to a collision or impact in the tangential direction. In other words, each lattice structure can deform along a tangential direction in the event of an impact, while in normal conditions of use, that is, in the absence of tangential forces, it supports the energy absorption bodies without deforming. In other words, preferably, each lattice structure of said plurality of lattice structures is configured to dampen a movement in a tangential direction of the energy absorption bodies, or to at least partially absorb the mechanical energy, that is, rotational kinetic energy, along one or more transversal directions with respect to the energy absorption layer.

More specifically, in accordance with the invention, energy absorption bodies are made available which preferably absorb energy along respective radial directions, that is to say, in such a way that the energy caused by a collision or impact along the above-mentioned radial directions can be dampened and, consequently, the head of an user undergoes minor decelerations.

The energy absorption bodies are associated with the monolithic lattice, which acts as a support, and thus gives structure to the energy absorption bodies. The energy absorption bodies are designed, as mentioned, to be interposed between the outer shell, that is, the outermost layer, of a helmet and the head.

Preferably, the monolithic lattice has an inner surface, suitable for facing the cavity of the helmet, and an outer surface facing the shell. The energy absorption bodies preferably extend between the inner surface and the outer surface of the monolithic lattice. The term “monolithic lattice”, and consequently also the term “lattice structure” means a structure, for example honeycomb type or porous, or spongy, or that incorporates a natural organic structure, provided with cavities or empty spaces that are homogeneously distributed throughout the lattice.

According to some embodiments, as mentioned above, the monolithic support structure is a three-dimensional structure with gyroids which yield in a direction orthogonal to the radial direction.

This yielding behaviour of the monolithic support structure and even more preferably of the monolithic lattice determines a sort of interruption in the transmission of rotational energy between the outer shell and the inner sliding cavity of the structure. This means that the rotational energy cannot be totally transmitted to the head of a user , which remains substantially stationary due to inertia. This condition makes it possible to reduce the risk of energy transmission to the head of a user and to allow a greater relative rotation of the outer shell with respect to the inner cavity in the event of a tangential impact with respect to the outer shell.

For technological needs or design choices, the entire energy absorption layer can be divided into a plurality of sub-portions or modules, which once moved close to or joined to each other define entirely the entire inner surface that defines the inner cavity of the helmet.

Basically, the absorption layer can be understood as a plurality of substructures or modules each including the monolithic support structure, such as, for example, the monolithic lattice and the plurality of energy absorption bodies.

Alternatively, the plurality of energy absorption bodies and the monolithic support structure, such as for example the monolithic lattice, is a single piece that covers the entire head of the user.

For both embodiments, the energy absorption bodies can be bodies separable from the monolithic support structure, such as for example the monolithic lattice, and in this case the monolithic lattice includes cavities where the energy absorption bodies can be inserted. Alternatively still, the energy absorption bodies can be made in one piece or integrally with the monolithic support structure, such as for example the monolithic lattice.

Each portion of the monolithic support structure, such as, for example, each lattice structure of the monolithic lattice that is located between adjacent energy absorption bodies serves to hold the energy absorption bodies in position, and preferably undergoes a slight compression in case of lateral or tangential impact, or does not obstruct a lateral movement of the energy absorption bodies, so as not to prevent the bending or folding of the respective energy absorption body. Preferably, therefore, each lattice structure is configured to provide a sort of support, or containment, for the energy absorption elements, while maintaining the possibility of being easily compressed in the event of an impact along a tangential direction.

Preferably, each of said energy absorption bodies has a greater energy absorption capacity in the radial direction than in a tangential direction. These bodies can therefore be bent in the event of a lateral or tangential impact. The tangential direction is in fact a direction parallel to a direction transversal to the radial direction, that is, a direction that passes transversely through the energy absorption layer. The energy absorption bodies in practice preferably have a preferential direction of greater compressive strength along the radial direction, that is to say a direction starting from a respective point on the surface of the head and perpendicular to it.

The presence of the energy absorption bodies allows the absorption of the radial energy caused by a collision or an impact, that is, the energy component along the radial direction. Furthermore, the structure portion of the monolithic support structure, like each lattice structure, yields in the event of a tangential impact, and favours the bending of the energy absorption bodies. This condition allows or facilitates relative rotation between the head of a user and the components of the helmet, so as to minimise the transmission of energy along directions other than the radial one, in particular along directions perpendicular to the latter.

Preferably, the energy absorption bodies are elongated bodies, that is to say having a preferred direction of local longitudinal extension, which coincides with the radial direction. These are cylindrical, cone-shaped or similar elongated bodies. The energy absorption bodies are preferably made of polymeric materials, for example of photosensitive resin.

The monolithic support structure, such as for example the monolithic lattice and each respective lattice structure, can be made according to Additive Manufacturing or 3D printing technologies. This allows customised and complex shapes to be obtained which can guarantee a better aeration of the head of a user with respect to the prior art solutions and do not have the shape limitations due to traditional moulding techniques.

Further advantages, characteristics and methods of use of the object of the invention will become evident from the following detailed description of its embodiments, presented merely by way of non-limiting examples.

It is however evident that each embodiment of the object of this disclosure can have one or more of the advantages listed above; however, no embodiment is required to simultaneously have all the listed advantages.

Reference will be made to the accompanying drawings, in which:

Figure 1 shows a schematic view of an energy absorption layer according to an embodiment of the invention.

Figure 2 shows a schematic view of the energy absorption layer wherein energy absorption bodies are detached from the respective monolithic support structure.

Figure 3 shows a side sectional view of a helmet according to an embodiment of the invention.

Figure 4 shows an enlarged side view of a section detail of Figure 3, where the energy absorption layer is shown.

Figure 5 shows a plan view of an energy absorption layer of the helmet of Figure 3.

Figures 6 to 9 show enlarged sectional views of a portion of the energy absorption layer according to further embodiments.

With reference to the accompanying drawings, the reference numeral 10 indicates an energy absorption layer 10 and the reference numeral 100 generally indicates a protection helmet according to an embodiment of the invention. The helmet 100 comprises an outer shell 1, preferably a padding (not shown in the drawings), and the energy absorption layer 10.

The energy absorption layer 10 includes a plurality of energy absorption bodies 3 and a monolithic support structure 8 represented, in the example of Figures 3-9, by a monolithic lattice defining, as described below, a plurality of portions of the lattice or a plurality of lattice structures 4.

In particular, each lattice structure 4 of the monolithic lattice is interposed between adjacent energy absorption bodies 3. In particular, the energy absorption bodies 3 are arranged or positioned between the inner cavity 101 and the outer shell 1. In other words, the portions of monolithic support structure 8 interposed between the energy absorption bodies 3 can be flexible and yielding solid bodies, or lattice structures.

The monolithic support structure 8, in this case for example of the above-mentioned monolithic lattice, has a plurality of hollow areas or empty spaces. Each of the energy absorption bodies 3 is housed within a respective space of the monolithic lattice. Each of the energy absorption bodies 3 can be made in one piece or be detachable with respect to the monolithic support structure 8, in this case, for example, the above-mentioned monolithic lattice.

According to the embodiment of Figures 1 and 2, the monolithic support structure 8 is made, for example, according to gyroid modelling, and there are therefore no empty spaces except for those occupied by the energy absorption bodies 3. In other words, according to the embodiment of Figures 1 and 2, the monolithic support structure 8 has empty spaces which accommodate energy absorption bodies 3, and the remaining portion of the structure does not have cavities. In all cases it is also possible to identify one or more radial directions 5, which extend between an inner region 101 of the helmet 100, for example a region for housing the head of a user, and the outside of the helmet. In particular, the energy absorption bodies 3 are configured to absorb mechanical energy, that is, kinetic and/or potential energy, along the one or more radial directions 5.

In other words, each of the energy absorption bodies 3 can absorb mechanical energy along one of the radial directions 5, in such a way that the set of energy absorption bodies 3 can allow the absorption of mechanical energy along a plurality of radial directions 5 that go from the surface of the outer shell 1 towards the inner padding 2.

According to a preferred embodiment, the energy absorption bodies 3 extend along three dimensions, that is, they have a three-dimensional shape. In particular, one of the three dimensions, called the extension dimension, can be greater than the other two dimensions, that is, it can have greater extension. More particularly, the extension dimension can extend along one of the radial directions 5. This configuration favours the absorption of mechanical energy by the energy absorption bodies 3 along one or more radial directions 5.

As mentioned above, the monolithic support structure 8 is a structure in which yields in the tangential direction in order to allow a movement of the energy absorption bodies 3.

Preferably, each portion of the energy absorption layer 8, and in the example the lattice structure 4, is configured to dampen a movement in a tangential direction of the energy absorption bodies 3 or to absorb at least partially the mechanical energy, that is, the rotational kinetic energy along one or more tangential directions 51 , which are transversal directions, for example perpendicular or oblique, with respect to one or more radial directions 5. In other words, each lattice structure of the monolithic lattice can guarantee at least a partial absorption of mechanical energy along one or more transversal directions 51 , since it yields along said transversal directions 51 with respect to the energy absorption bodies 3.

The energy absorption bodies 3 are in fact destined to bend or collapse substantially in the event of an impact in a tangential direction.

According to a preferred embodiment, the energy absorption bodies 3 have a tubular shape with constant or variable section. In particular, they can have a tubular shape wherein the section does not vary moving along the direction of extension, or they can have a tubular shape wherein the section narrows or widens or is variable moving along the direction of extension. For example, the energy absorption bodies 3 can have a tubular shape with a constant section (Figure 4), or a hollow truncated cone shape (Figures 8 and 9), or a hollow barrel shape (Figures 6 and 7).

Preferably, as mentioned above, the energy absorption bodies 3 are associated with the monolithic support structure 8, and therefore with each portion thereof which can be a lattice structure 4, in a fixed or removable way. For example, the energy absorption bodies 3 can be housed, preferably with very low tolerances, inside suitable spaces formed in the monolithic support structure 8, that is, for example, between each lattice structure 4 and can be released from the latter or can be directly connected to the lattice structure 4. Alternatively, the energy absorption bodies 3 are only inserted with interlocking between the lattice structures 4.

The energy absorption bodies 3 can be released from, or re-associated with, the lattice structure 4 in case of disassembly or assembly.

The energy absorption bodies 3 can alternatively be made in a single piece with the monolithic support structure 8.

Preferably, the energy absorption bodies 3 are made of polymeric material, for example a photosensitive resin. Alternatively, they can be made of very thin metal material which can be chosen on the basis of structural needs or of thermoplastic material.

In general, the energy absorption bodies 3 are made of a material which allows a stiffness and a plastic yielding to be guaranteed along one or more radial directions 5 which is similar to that of the expanded polystyrene used in the prior art solutions.

Preferably, each portion of the monolithic support structure 8, like each lattice structure 4, is made of polymeric material, for example photosensitive resin or another material suitable for being produced by 3D printing or alternatively consisting of a plurality of resin modules thermoplastic moulded with traditional techniques such as injection moulding.

According to a preferred embodiment of the invention, the above-mentioned monolithic support structure 8, such as for example the above-mentioned lattice as a whole or each lattice structure 4 and/or the energy absorption bodies 3 are made by means of 3D printing or Additives Manufacturing technologies. These technologies make it possible to create complex shapes that can effectively absorb the mechanical energy and at the same time allow improved aeration of the head of a user, thanks to the presence of special aeration channels or cavities. Furthermore, 3D printing technologies can allow a customisation of each portion of the monolithic support structure 8, such as for example of each lattice structure 4 and/or of the energy absorption bodies 3, in such a way as to make the absorption of mechanical energy more efficient, for example as a function of the shape of the head of a user.

In particular, it is possible to modify the thickness and the relative dimensions of the energy absorption bodies 3 and/or of each lattice structure 4 to more effectively define the absorption of mechanical energy along the one or more radial directions 5 and the behaviour along the one or more transversal directions 51.

In fact, Figures 4-7 show energy absorption bodies with different thicknesses.

Preferably, each lattice structure 4 is made according to a spongy structure, that is, a structure consisting of thin columnar structures with different orientation and intertwined with each other to form different cavities within the structure itself. For example, the lattice structure 4 can be inspired by the shape of a spongy bone tissue.

The invention, described according to preferred embodiments, allows the set aims and objectives to be achieved for overcoming the limits of the prior art.

In particular, the energy absorption bodies 3 can absorb mechanical energy along the one or more radial directions 5 but not in the tangential direction. Each lattice structure 4 can guarantee at least partial absorption of mechanical energy along one or more transversal directions 51. In this way, an interruption of motion in the tangential direction is created thanks to a bending of the energy absorption bodies 3 and the absorption by the lattice structure. In this way it is possible to obtain a relative rotation between the head of a user and the helmet in the event of a tangential impact to the outer surface of the helmet, in such a way that the transmission of rotational forces to the head of the user can be minimised.

For example, the energy absorption bodies 3 are called upon to absorb mechanical energy when the impact occurs along their direction of extension. The energy absorption bodies 3 can rotate relative to the head of the user and return to their original position at the end of the impact. In this way, the energy absorption bodies 3 can absorb any subsequent impacts along their direction of extension.

Furthermore, the invention allows a greater thermal comfort to be obtained for a user, thanks to the improved aeration made possible by the lattice structure 4, with respect to the prior art solutions. It is to be understood that the energy absorption layer 10 as a whole can be a single piece covering the entire head of a user, or alternatively it can be a module structure, comprising a plurality of sub-portions each including one or more energy absorption bodies and a portion of the monolithic support structure. The invention has thus far been described with reference to its embodiments. It is to be understood that there may be other embodiments pertaining to the same inventive core, all falling within the scope of protection of the claims set forth below.