Patent ID: 12185785

DETAILED DESCRIPTION

FIG.1illustrates an example of a method100for fitting a pre-existing standard helmet206to a user's head202. As illustrated inFIG.2aandFIG.2b, the helmet206includes an optronic device208that is intended to be placed over the user's eyes204when the helmet is worn by the user. The optronic device208may for example be a helmet-mounted display. The standard helmet is defined according to a norm or standard suitable for a large number of users. For example, the helmet206may be a helmet of standard size (for example S, M, or L) on which the optronic device208is pre-mounted. In one example, the position of the optronic device208may be adjustable. The position can be approximately adjusted by placing the helmet on the user's head so that the device208is positioned in front of the user's eyes204.

In step102, the method100involves measuring the dimensions of the user's head. For example, the dimensions of the head may include a volume of the head202represented by spatial coordinates of the surface of the head and a position of the eyes204. For example, a 3D scan of the user's head202can be performed using a 3D scanner. The scan can for example indicate the position of the pupils when the eye is exposed to different light intensities. Furthermore, the 3D scan can indicate dimensions such as the surface area of different zones of the head202, for example temples, forehead, nape, top of the head, etc.

In step104, the method100comprises obtaining dimensions of the helmet206. For example, the dimensions of the helmet can be obtained after the helmet206has been designed (by computer-aided design), or measured after manufacturing (by reverse engineering), or obtained from a user manual of the standard helmet. In another example, a 3D scan of the helmet can be carried out to determine the dimensions thereof. The dimensions of the helmet206may for example include a volume of the helmet206represented by spatial coordinates of the inner face310of the helmet206. The shape of an inner face310of the helmet206may be determined. For example, the thickness of the helmet206may be uniform or may include zones of different thicknesses. In one example, the dimensions of the optronic device208may be measured, such as the length or width of the device208, or the position of a portion of the device208intended to be placed on the eye204.

In step106, the method100comprises defining a lining300for the helmet206so as to ensure the positioning of the optronic device in front of the user's eyes, the lining300having a top face308athat is intended to be applied against the inner face310of the helmet206and a bottom face308bthat is intended to be applied against the user's head202, the lining300having a flexible cellular structure, the manufacture of the lining300being adapted to the dimensions of the head202and to the dimensions of the helmet206. In particular, the dimensions of the head202and of the helmet206measured in steps102and104are used to define the lining300so that the optronic device208is placed precisely in front of the user's eyes204.

The lining300can be defined using three-dimensional modelling software taking into account the head dimensions measured in step102and the helmet dimensions obtained in step104.

The lining300may be defined to comprise several portions. For example, as illustrated inFIGS.3aand3bshowing examples of a lining300for a helmet206as viewed from the front and the top, the lining300may comprise several portions302a-306ccorresponding to zones of the user's head202. In the example shown inFIG.3a, the lining300comprises nine portions302a-306c. For example, the portions302a,302cmay correspond to the user's temples, the portion302bmay correspond to the user's forehead, the portion304bmay correspond to the user's nape, the portion306bmay correspond to the top of the head202, and the portions304a,304c,306a,306cmay correspond to different side portions of the head202. The zones of the head may be defined by spatial coordinates of the surface area of the user's head that are for example obtained by a 3D scan of the head in step102. In another example, as shown inFIG.3c, the lining may comprise five portions302b,306a,306b,306c,304bcorresponding to the user's forehead, nape, top of the head, and temples.

The lining300may be defined to include several portions, in which some portions are connected by one or more flexible links. As illustrated inFIG.3b, the portions302a-306cof the lining300may be connected by links320to connect several portions. The links320may for example connect the portion306awith the portion306b, the portion306bwith the portion306c, the portion302awith the portion302b, the portion302bwith the portion302c, the portion304awith the portion304b, the portion304bwith the portion304c, the portion302bwith the portion306b, and the portion306bwith the portion304b. In another example, several links320may connect two portions.

As illustrated inFIGS.3a-3d, the lining300comprises different separate portions302a-306c. These portions are advantageous because they enable the lining to be manufactured flat. Indeed, in these examples, the portions302a-306care defined so as to be detached from each other, thereby obtaining a flat lining that can then be placed in the helmet206, adopting the shape of the inner face310of the helmet206. In particular, the lining300may be manufactured flat, as shown inFIG.3c(see details below). The top face308ais designed to be in contact with the inner face310of the helmet206and can therefore be flat during manufacture. The flexibility of the lining300(generated by the flexible cellular structure and the flexible links320) and the various portions302a-306cthen enable the lining300to be inserted into the helmet206, with the shape of the lining300adapting to the shape of the inner face310of the helmet206. In one example, each portion302a-306ccan be manufactured separately, and then the portions302a-306ccan be assembled to form the lining300. For example, the detached portions302a-306cmay be defined such that cells in the cellular structure allow the portions302a-306cto be assembled by interlocking to form the lining300. The manufacture of detached portions302a-306callows the portions302a-306cto be printed separately, thereby facilitating the manufacture thereof (by 3D printing, for example). Advantageously, it is possible to use small manufacturing means, which may be transportable and less expensive than the means required to manufacture a complete lining. In another example, the portions can be defined to be partially detached from each other.

In another example, the portions302a-306cmay be defined such that the lining300is manufactured directly with the shape of the inner face310of the helmet206. For example, the portions302a-306cmay be defined with a shape matching the inner face310of the helmet206.

In order to adjust the position of the optronic device208so that said optronic device is positioned in front of the user's eyes202, the thickness of the different portions302a-306ccan be varied. For example, the thickness of the portion306bcorresponding to the top of the head202may be greater than the thickness of the portion306ato adjust the position of the device208. In addition to enabling the optronic device208to be precisely adjusted in front of the eyes204, varying the thickness of the different portions302a-306calso allows the user to make adjustments for comfort, particularly where the helmet206is of standard size. For example, the portions302a,302ccorresponding to the user's temples may be thicker than the portion306bcorresponding to the top of the head202to improve the comfort of the helmet206. For example, the thickness of the different portions302a-306cmay be between 1 mm and 20 mm. In another example, as shown inFIG.3b, a given portion302a-306cmay have different thicknesses. For example, each of the portions306a,306bmay have different thicknesses. For example, the thickness may vary gradually within a single portion302a-306c.

In one example, the cellular structure can have a non-uniform density, the density representing the number of cells per unit area of the flattened lining. For example, the portion corresponding to the zone of the user's nape may have a cellular structure with a higher density than the portion corresponding to the zone of the top of the user's head. For example, all or some of the portions302a-306cof the lining300shown inFIG.3amay have different cell densities. In another example, the density of the cells in the lining300can be adapted to different zones of the head. For example, a portion of the lining300corresponding to the zone of the user's nape may have a cellular structure with a higher density than the portion corresponding to the zone of the top of the user's head. Thus, the flexibility of the lining can be varied by varying the density of the cells. The lower the density, the more flexible the lining300will be. Decreasing the density for example at the nape therefore enables the user to move his head202more easily (head movements cause a change in the volume of the neck, while speaking or chewing causes a change in the shape of the temples and/or the jaw). In particular, the flexibility of the lining300may be provided by the vertical walls of the cells, for example enabling the lining300to be manufactured flat and then inserted into the helmet206. Furthermore, the lining may be vertically flexible, i.e. the lining may be compressed between the top face308aand the bottom face308b. For example, superposing several layers of cells can facilitate vertical flexibility. This enables the user to move his head202more easily, and to insert his head202into the helmet206more easily. In another example, the same portion302a-306cmay have a variable cell density. For example, the density may change gradually within the same portion302a-306c.

In one example, the method100can also comprise measuring the dimensions of the equipment placed inside the helmet206and, during step106, adapting the definition of the lining to the dimensions of the equipment. For example, in step102, the user can wear equipment such as a fireproof hood, a comfort fabric (for example a foam lining placed between the user's head and the lining300to improve comfort when wearing the helmet), a mask, goggles, etc. The dimensions of the user's head can thus be measured using a 3D scan of the head and the equipment, indicating for example the volume of the head and the equipment. In another example, equipment may be placed in the helmet during step104. For example, a headset or a microphone can be built into the helmet, and the dimensions of the helmet can take into account the dimensions of the equipment.

As shown inFIGS.4aand4billustrating two portions of the lining300, the cellular structure defined in step106includes cells forming a pattern. For example, the pattern of the cellular structure may be a lattice pattern (such as a grille). In the example shown inFIG.4a, a uniform rectangular pattern is used (comprising rectangular cells). In the example shown inFIG.4b, a uniform honeycomb pattern is used (comprising honeycomb-shaped cells). In another example, a V-shaped or circular pattern may be used. In another example, a non-uniform pattern can be used, i.e. comprising cells of different sizes and/or shapes. In one example, a pattern comprising rectangular cells and honeycomb cells may be used, for example. In one example, during step106, the cellular structure may comprise through-cells extending from the top face308ato the bottom face308b. For example, as shown inFIG.3c, the rectangular cells in the portion306band the parallelepipedic cells may be through-cells extending from the top face308ato the bottom face308b. The through-cells allow for a flexible lining300that can be easily inserted and removed from the helmet206, allowing the user to move his or her head202and allowing the skin to breathe. In another example, as shown inFIGS.3band3cshowing the lining300from the side, several layers of cells may be arranged on top of each other.

In one example, during step106, a first zone and a second zone of the cellular structure may be defined, the first zone having a first pattern and the second zone having a second pattern. For example, the first zone and the second zone may correspond to a separate portion302a-306cof the lining300as shown inFIG.3a. Each portion302a-306ccan have a different pattern (different pattern and/or different size cells). Alternatively, some portions302a-306cmay also have the same pattern while other portions302a-306cmay have a different pattern. In another example, the first zone and the second zone may correspond to zones of the head such as the nape, the temples or the top of the head. Each zone of the lining300corresponding to a zone of the head can have a different pattern (different pattern and/or different size cells). Alternatively, some zones of the lining300corresponding to a zone of the head can also have the same pattern while other zones may have a different pattern. For example, the portion302amay have a honeycomb pattern and the portion302bmay have a circular pattern. As shown inFIG.3c, the portion306bmay have a rectangular pattern and the portions306a,306cmay have a parallelepipedic pattern. In another example, a given portion302a-306cmay have several zones, each zone comprising different cells. In another example, the different patterns may be the same pattern (for example honeycomb) with different sizes. For example, the size of the pattern may change gradually within the same portion302a-306c. Adapting the pattern therefore allows the flexibility of the lining300and user comfort to be adjusted. Indeed, different patterns allow for different flexibilities that can, for example, facilitate movement of the head (for example, about the user's nape).

In step108, the method100comprises manufacturing the lining300as defined in step106. As mentioned above, in one example, the lining300can be manufactured flat by defining several flat portions302a-306c. The lining300may be manufactured by additive manufacturing, such as by stereo lithography of material in liquid state, powder sintering, and fusion of solid-wire material (for example using three-dimensional (3D) printing). The lining300can be made of elastomeric material. For example, the lining300can be made of nylon, polyurethane or polystyrene. In one example, different portions of the lining300may be made of different materials. In particular, materials of different flexibility may be used, helping to improve user comfort and allowing the user to easily move his head covered by the helmet206containing the lining300. In one example, the lining300may be manufactured flat by additive manufacturing. As noted above, the lining300may comprise several portions302a-306b. The portions302a-306benable the lining300to be manufactured flat. Indeed, each portion can be manufactured by flat 3D printing, as illustrated inFIG.3d. Each portion can be made of a flexible material. The flexibility of the material of the lining300and the different portions302a-306cthen enable the lining to be inserted into the helmet and to easily adapt to the shape of the inner face310of the helmet. Manufacturing the portions302a-306cflat therefore simplifies manufacturing and reduces manufacturing time. Indeed, there is no need for an additional step such as the manufacture of a 3D-printing substrate in the shape of the helmet, which would have to be removed afterwards once the helmet has been made. This also reduces the waste generated by the manufacturing process since there is no additional material to remove. Moreover, flat manufacturing allows the lining300to be manufactured directly on a substrate of the printer, without requiring a manufacturing substrate having the shape of the desired lining (for example, a substrate having the shape of the inner face310of the helmet206). For example, in the case of the lining inFIG.3d, the portion306bcorresponding to the top of the head may be first manufactured flat by 3D printing on the substrate of the printer. The links320can be manufactured by 3D printing, allowing the portion306bto be connected to the other portions302b,306a,304b,306b. These links can be flexible links. The links can be made of a flexible material suitable for 3D manufacturing, such as a polymer (for example nylon, polyurethane or polystyrene). The lining300and the links320can be made of the same material or a different material. Each portion is then manufactured flat by 3D printing about the portion306b, with the portion306bremaining stationary during manufacture. All of the portions of the lining300can therefore be manufactured flat.

In another example, as shown inFIG.3b, the lining300may be printed on a substrate having the shape of the inner face310of the helmet206. For example, a substrate can be obtained in advance for each helmet of standard size (for example S, M, or L) and the lining can be manufactured on the substrate corresponding to the helmet into which the lining300will be inserted. For example, the substrate can be obtained by moulding the standard helmet. This ensures that the lining300, once inside the helmet206, fits the shape of the inner face310of the standard helmet206used.

These manufacturing methods reduce material waste compared to the machining or moulding typically used in the manufacture of customized helmets. Furthermore, these methods allow a helmet adapted to fit a user's head to be made quickly from an existing helmet.

In step110, the method100includes placing the lining inside the helmet206. The user can then wear the helmet with the optronic device208precisely adjusted to his eyes as a result of the lining placed inside the helmet206.

The invention described above both provides accurate positioning of the optronic device208on the user's eyes, and therefore a helmet206that is stationary when worn, and provides comfort when wearing the helmet, even for an extended period of time. Thus, the method100described above achieves a balance between flexibility and rigidity of the lining300, allowing for precise positioning and comfort. Furthermore, the portions and the flat manufacturing of the portions help to simplify manufacturing, to reduce manufacturing time, and to reduce manufacturing waste.

Although the invention has been illustrated and described in detail using a preferred embodiment, the invention is not limited to the examples disclosed. Other variants may be deduced by the person skilled in the art without thereby moving outside the scope of protection of the claimed invention. For example, althoughFIGS.4aand4billustrate honeycomb or rectangular cells in a uniform pattern, a person skilled in the art will understand that there are many patterns available to vary the properties of the lining, for example flexibility and comfort. Furthermore, the person skilled in the art will understand that the thickness, cell density, and pattern can be simultaneously adapted to position the optronic device in front of the user's eyes, as well as to improve comfort and head movement. Moreover,FIGS.3a-3dillustrate examples of portions of the lining. However, the person skilled in the art will understand that there are other examples comprising different numbers, shapes and designs of portions that can be used to fit a helmet to a user's head.