EP2974612B1 - Damping helmet - Google Patents

Description

The invention relates to a protective helmet for sports activity. Such activities may include downhill skiing, ski touring or snowboarding. The invention also extends to the practice of climbing, mountaineering, cycling or the practice of snowmobiling. Generally, a helmet forms a protection of the head, to protect the skull of the shocks that it could undergo when the user makes a fall, when an object is projected in its direction or during a collision with an object or a third person.

A classic helmet construction includes an outer shell and an inner cap. The outer shell is generally rigid, and is for example made by molding / injection of a thermoplastic material such as ABS (Acrylonitrile Butadiene Styrene) or PC (PolyCarbonate). Commonly, the inner cap is made of an expanded material such as EPS (Expandable PolyStyrene) or EPP (Expandable PolyPropylene). In order to guarantee good comfort for the user, the helmet is generally equipped with an internal cap which may, for example, be made of foam covered with fabric. The inner cap is attached to the inside of the inner cap.

A helmet is intended to reduce the risk of injury to the skull of the user, while having the least weight possible to not affect the comfort of the user.

A good helmet must therefore meet two contradictory requirements, on the one hand, have as much cushioning material as possible and, on the other hand, be as light as possible to be portable easily and not to inconvenience the user.

To ensure the safety of users, there are several standards generally defining tests and acceptance thresholds that are applied to helmets that are candidates for certification in the associated discipline. Depending on the sporting activity, the normative requirement may differ. Thus, a standard covers a specific activity. From these requirements, it follows from the characteristics that the helmet must present to provide the required protection. For example, these characteristics correspond to properties of penetration resistance and shock absorption properties as a function of the activity performed, in different areas of the helmet.

Thus, it appears a strong need to design a helmet with a good damping in its summit part, this zone being often a critical zone for the success of test with a view to obtaining a homologation.

In this zone, the damping characteristics of the helmet depend mainly on the design of the inner cap.

The most common shell construction is in the form of an envelope reproducing the morphology of the skull. To obtain the desired damping, suitable materials are used and / or the thickness of the envelope is varied. This results in a design that can weigh down the helmet, source of discomfort for the user.

Other constructions propose to report independent studs, directly on the outer shell ( US 4,766,614 ), on an inner envelope ( GB 2,240,255 ; US 4,239,136 ) or associated with the cap ( US7,774,866 ; EP 0 423 379 ). In all cases, these pads are sized to operate in compression. The damping is thus achieved by crushing the pads. In some embodiments, these pads are used to wedge the head. These different constructions, incorporating studs reported, are complex and expensive to achieve. One difficulty relates to the attachment and maintenance of the pads on the helmet.

Another construction provides an inner cap with ventilation channels defining protrusions protruding towards the user's head. This type of structure is characterized by a cap having a relatively thick layer from which the projections extend over a low height. The damping is here made by the thick layer, the projections having a channeling role of the air flow ensuring the ventilation of the top of the skull. In this construction, to obtain the desired properties, the reliefs have a height less than the thickness of the cap. The document EP 2 716 175 illustrates this type of helmet.

The object of the invention is to provide an improved helmet.

One goal is to provide a lightweight helmet structure, having good damping property.

Another goal is to provide a helmet whose structure comprises few assembled components.

Another purpose is to provide an economical helmet whose process of realization is simple.

• une coque externe,
• une calotte, constituée d'un matériau parmi l'EPS, l'EPP, la calotte étant disposée à l'intérieur de la coque et présentant une partie supérieure destinée à recouvrir au moins la partie sommitale du crâne, la calotte comprenant une première couche d'épaisseur « e » couvrant sensiblement la partie supérieure et plusieurs plots faisant saillies de la première couche en direction de la tête, d'une hauteur « h », la première couche et les plots formant une seule et même pièce.

For this purpose, the subject of the invention is a helmet as described in independent claim 1 and comprising:

• an outer shell,
• a cap, made of a material from the EPS, the EPP, the cap being disposed inside the shell and having an upper part intended to cover at least the top part of the skull, the cap comprising a first layer of thickness "e" substantially covering the upper part and several studs protruding from the first layer towards the head, a height "h", the first layer and the pads forming a single piece.

The helmet is characterized by the fact that the height of the pads is greater than the thickness of the first layer.

This structure allows to have, with few parts, a cap attached to an outer shell, a lightweight helmet with good damping characteristics. This construction allows a good anchoring of the pads on the cap and the height of the pads allows deformation by bending and / or buckling, which improves the damping properties of the helmet. In addition, the helmet is compact and has an outfit. This helmet is light and ventilated thanks to this specific construction. It also allows the use of simple cap, removable, can easily be changed.

• L'épaisseur « e » de la première couche est comprise entre 1 et 17,5 millimètres.
• La hauteur « h » des plots dans la partie supérieure est comprise entre 10 et 35 millimètres.
• la section moyenne des plots est comprise entre 0,5 et 5 centimètres carré.
• Plusieurs plots de la partie supérieure sont dimensionnés de sorte que leur hauteur « h » est supérieure à la plus petite dimension caractérisant la section moyenne de ces plots.
• Les plots sont répartis aléatoirement dans la partie supérieure.
• Le sommet des plots est destiné à être en contact avec la tête ou une coiffe couvrant la tête.
• Les plots présentent une forme sensiblement parallélépipédique.
• La calotte est une pièce monolithique.
• La section de la base des plots est sensiblement la même que la section du sommet des plots.
• Les plots sont orientés de sorte que leur hauteur s'étende sensiblement selon une direction verticale.
• La calotte est réalisée par moulage.
• Les plots sont évidés.

Optionally, the invention may have any of the following optional features taken alone or in combination:

• The thickness "e" of the first layer is between 1 and 17.5 millimeters.
• The height "h" of the studs in the upper part is between 10 and 35 millimeters.
• the average section of the studs is between 0.5 and 5 square centimeters.
• Several pads of the upper part are dimensioned so that their height "h" is greater than the smallest dimension characterizing the average section of these pads.
• The pads are randomly distributed in the upper part.
• The top of the studs is intended to be in contact with the head or a cap covering the head.
• The studs have a substantially parallelepiped shape.
• The cap is a monolithic piece.
• The section of the base of the studs is substantially the same as the section of the top of the studs.
• The pads are oriented so that their height extends substantially in a vertical direction.
• The cap is made by molding.
• The studs are hollowed out.

• la figure 1 est une vue en perspective d'un mode de réalisation principal d'un casque selon l'invention ;
• la figure 2 est une vue de dessous en perspective de l'intérieur du casque ;
• la figure 3 est une vue de dessous du casque ;
• la figure 4 est une vue en coupe selon IV-IV de la figure 3 ;
• les figures 5 à 6 sont des coupes partielles illustrant différents modes de déformations des plots selon l'invention.

Embodiments of the invention will now be described, by way of nonlimiting examples, with reference to the accompanying drawings, in which:

• the figure 1 is a perspective view of a main embodiment of a helmet according to the invention;
• the figure 2 is a perspective bottom view of the inside of the helmet;
• the figure 3 is a bottom view of the helmet;
• the figure 4 is a sectional view along IV-IV of the figure 3 ;
• the Figures 5 to 6 are partial sections illustrating different modes of deformation of the pads according to the invention.

The helmet 10 comprises an outer shell 11, a collar 12, a cap 13, ear cushions 14 and a jugular strap 15.

In the rest of the description, terms such as "horizontal", "vertical", "longitudinal", "transversal", "superior", "lower", "up", "down", "before" will be used. , "Back", "anterior", "posterior". These terms must be interpreted in a relative sense in relation to with the position that the helmet occupies on the head of a user in normal posture, and the normal direction of advancement of the wearer.

The helmet comprises an upper portion 101 for covering at least the "top part" of the skull, that is to say the top of the skull. It is defined by an area covering an upper part of the frontal bone and an upper part of the parietal bone. In this example, this upper portion 101 of the helmet is composed of an upper portion 111 of the outer shell and an upper portion 131 of the cap.

The outer shell 11 is monolithic, that is to say made in one block. Here it is made of polycarbonate (PC). Alternatively, it is acrylonitrile butadiene styrene (ABS), a material loaded with carbon fibers or natural fibers. The outer shell 11 is molded, for example, injected.

The cap 13 is here also monolithic. It is made of expanded polystyrene foam (EPS, which comes from the English "Expandable PolyStyrene"). It may alternatively be expanded polypropylene (EPP, which comes from the English "Expandable PolyPropylene") or other material, preferably expanded material. It is attached to the outer shell 11 to cover an inner surface 112 of the outer shell 11.

The cap 13 is designed to also surround the head of a user. The construction of its internal envelope will be detailed later.

The cap 13 may be a separate part of the outer shell 11, and assembled with the outer shell 11. Alternatively, it may be overmoulded on the outer shell 11, it is called so-called thermoforming technology or "in-mold".

To improve comfort, the outer shell 11 and the cap 13 may include openings positioned vis-à-vis so as to allow the arrival and / or evacuation of a flow of air ensuring the ventilation of the skull. the user.

In this example, the lower part of the helmet is delimited by the flange 12 fixed on the cap. This flange marks the lower edge of the outer shell 11 together with the lower edge of the cap 13. The collar is optional, the invention also applying to helmets having no flange defining the lower edge of the helmet.

The cap 13 has a structure comprising two levels in the direction of the thickness.

The first level forms a first layer 132 of thickness "e" covering the skull of the user. This first layer substantially reproduces the shape of the outer shell. The outer surface 1321 of this first layer is fixed on the inner surface 112 of the outer shell. This assembly can be achieved by gluing, melting, overmoulding or other technology. The thickness e of this layer is not necessarily constant over the entire internal surface of the helmet. For example, it may be thicker on the upper part of the cap and less thick on the lower part, namely, the front, side and rear. As we have seen previously, the first layer 132 may include openings for aeration of the skull.

The second level of the structure of the cap comprises a set of reliefs 133, 134 projecting from the inner surface 1322 of the first layer 132, in the direction of the head of the user. The shape of these reliefs varies according to their positioning.

In the lower part of the cap (the front, side and rear parts), the reliefs form blocks 134, for example parallelepipedal of variable thickness. Thus, each block is slightly thick in its lower part and thicker in its upper part. The blocks are regularly distributed on the inner lower periphery of the cap 13. Channels are thus formed between the blocks. These channels are used for the circulation of air for ventilation of the skull.

In the upper part 131 of the cap (top part), the reliefs form studs 133. In the illustrated example, these studs are parallelepipeds having a height "h" substantially constant. These parallelepipeds have however, different sections, relative to each other. In a variant, they may have identical sections. Alternatively, these pads may take other polyhedral or cylindrical forms. It can be truncated pyramids, cylinders, truncated cones. Similarly, the height of these studs is not necessarily constant. It is thus possible to provide areas where the height of the pads is greater in order to obtain, for example, more damping. Again, channels are formed between the pads. These channels are used for the circulation of air for ventilation of the skull. According to the embodiment described, the distribution of the pads is random in the upper part 131. Alternatively, the distribution can follow a regular pattern.

The total thickness "T" of the cap corresponds to the sum of the thickness "e" of the first layer and the height "h" of the reliefs, blocks 134 or pads 133. The total thickness "T" may vary depending on the parts of the cap concerned.

The invention also resides in the fact that, in the upper portion 131 of the cap, a majority of pads have a height sufficient to obtain a deformation complementary or alternative to the compression of the pad, in order to improve the damping properties of the pad. helmet. This deformation can be "buckling" or bending. In this case, the pads are sized and arranged so that they can not only compress but also deform in a non-axial direction. Thus, the pads do not deform only by compression as in the majority of the constructions of the prior art.

The Figures 5 and 6 illustrate examples of deformations of these pads following an impact materialized by the vector "F". The stud 133, biased by the effort "F", bears against the skull or the cap, represented here by the plane "P". The stud 133 then deforms in compression, initially, then in a non-axial direction, in a second step, because of its dimensioning. To the figure 5 the deformation is similar to a buckling. To the figure 6 the deformation is like a flexion. The deformation of the stud can be different from one block to another depending on the impact zone and the dimensions of the stud. It is not necessary that all the studs respect the recommended ratio, the absorption of the shock can be cashed by a few pads. The damping properties are nevertheless better if there are many studs having a height greater than the thickness of the first layer.

To obtain this complementary or alternative deformation, the proposed construction comprises sufficient anchoring of the base of the studs and a height of the studs allowing this additional deformation. The first layer 132 of thickness "e" and allows to secure the pads together to create a monobloc structure and homogeneous. In addition, in order to obtain a satisfactory deformation, the height "h" of the pads is greater than the thickness "e" of the first layer.

Moreover, to obtain a complementary or even more efficient deformation, some studs placed in areas of preferred deformations have a height "h" greater than the smallest dimension characterizing the average section of these pads. The smallest dimension may be a side of a square section, the smallest height of a parallelogram section, the diameter of a cylinder. The higher the height is greater this dimension, the more it will facilitate the additional deformation sought. The pads can then more easily deform in a non-axial direction.

According to one embodiment having good damping, the section of the base of the pads is substantially the same as the section of the top of the pads. It is therefore best to avoid having pyramid-shaped studs or tilted cones. If this is not the case, the stud will essentially deform in compression which is not the desired behavior.

It has been found, surprisingly, that compared to conventional "full" caps, that is to say without pads, damping properties of a cap comprising such pads are significantly better at total thickness equivalent. For example, the acceleration measured at the level of the head after an impact on the summit part is at least 15% less between a cap with studs and a cap without studs.

Thus the pads 133 act as shock absorbers (crashbox) similar to car bumpers. The kinetic energy generated by the shock is thus dissipated by these pads in addition to the absorption inherent in the material of the cap. This double dissipation improves the damping compared to a cap without pads of equivalent thickness.

The damping therefore results mainly from the deformation of the pads 133 and weakly via the thickness of the first layer 132. The first layer serves essentially to create a monobloc structure by connecting the pads together.

In these examples, the height ratio "h" on thickness "e" is greater than one. Good damping results are obtained with a thickness "e" of between 1 and 17.5 millimeters and / or with a height "h" of between 10 and 35 millimeters, the previously defined ratio to be respected. For comfort, the total thickness "T" of the cap is preferably less than 40 millimeters.

Similarly, the average section of the pads is preferably between 0.5 and 5 square centimeters. With a small section, the pad deforms more easily in a non-axial direction. With a larger section, the stud deforms less in a non-axial direction. However, the top 1331 of the stud has a larger contact area with the skull which is more comfortable because the transmitted stress is lower. A good compromise is a section between 1 and 4 cm ² .

According to a preferred embodiment, the first layer 132 is characterized by a small thickness "e", less than 10 millimeters. This small thickness makes it easy to adapt the shape of the shell to that of the outer shell while favoring high-damping pads. In addition, the reduced thickness of the first layer and the spacing of the pads reduce the amount of damping material effective and necessary. As a result, it helps to lighten the helmet, which is a very important element important, even fundamental, for a sports helmet. It was found that, unlike conventional helmet constructions, it was not necessary to have a continuous thickness over the entire surface of the cap to achieve a good level of protection.

The cap is a "monolithic" piece in the sense that the first layer 132 and the pads 133 form a single piece. Nevertheless, the cap may be constructed in several parts, each comprising a first layer and reliefs. By being a single block, it greatly simplifies the realization of the cap. On the other hand, it reduces the number of components of the helmet compared to a helmet with many studs reported.

To further simplify the realization of the cap, the pads are designed so that the cap can be unmolded by a simple movement of the tool. This means, in this example, that the pads are oriented so that their height extends substantially in a vertical direction.

Thanks to the invention, the cap can be made using an economical material, the EPS and or EPP, making the most of its damping properties. Thanks to the obvious of the inner envelope of the cap by the realization of the pads, it reduces the volume of material of the cap and therefore the weight of the helmet. This lightening brings wearing comfort to the user without denying the required safety. The reduction of damping material is then compensated by the potential of deformation of the pads.

In this example, the top 1331 of the pads 133 is intended to be in contact with the head or a cap covering the head. Generally, the helmets incorporate a cap making the interface between the head of the user and the cap. This brings a better comfort because the cap can be made of a material more pleasant to the touch. In addition, it can easily be changed if it deteriorates, for example, by prolonged contact with sweat.

In the illustrated embodiment, the pads are full. Alternatively, one can consider to hollow out the pads to further lighten the structure. In this case, the cap would consist of hollow studs.

In summary, the studs 133 of the upper part 131 of the cap serve two main functions, on the one hand, shock absorption and, on the other hand, ventilation of the skull.

The invention is not limited to these embodiments. It is possible to combine these embodiments.

The invention is not limited to the embodiment previously described but extends to all the embodiments covered by the appended claims.

Claims (14)

1. Helmet (10) comprising:

   - an outer shell (11),

   - a cap (13) consisting of a material chosen from among EPS and EPP, the cap being arranged inside the shell and having an upper part (131) intended to cover at least the top part of the skull, the cap comprising a first layer (132) of thickness "e" substantially covering the upper part and a plurality of blocks (133) projecting from the first layer in the direction of the head, by a height "h", the first layer and the blocks forming one and the same part (13),

   characterized in that the height "h" of the blocks is greater than the thickness "e" of the first layer.
2. Helmet (10) according to Claim 1, characterized in that the thickness "e" of the first layer is between 1 and 17.5 millimetres.
3. Helmet (10) according to Claim 1, characterized in that the thickness "e" of the first layer is less than 10 millimetres.
4. Helmet (10) according to one of the preceding claims, characterized in that the height "h" of the blocks in the upper part is between 10 and 35 millimetres.
5. Helmet (10) according to one of the preceding claims, characterized in that the average cross section of the blocks is between 0.5 and 5 square centimetres.
6. Helmet (10) according to one of the preceding claims, characterized in that a plurality of blocks of the upper part are dimensioned such that their height "h" is greater than the smallest dimension characterizing the average cross section of these blocks.
7. Helmet (10) according to one of the preceding claims, characterized in that the blocks are distributed randomly in the upper part.
8. Helmet (10) according to one of the preceding claims, characterized in that the apex (1331) of the blocks is intended to be in contact with the head or a cover covering the head.
9. Helmet (10) according to one of the preceding claims, characterized in that the blocks have a substantially parallelepipedal shape.
10. Helmet (10) according to one of the preceding claims, characterized in that the cap is a monolithic part.
11. Helmet (10) according to one of the preceding claims, characterized in that the cross section of the base of the blocks is substantially the same as the cross section of the apex of the blocks.
12. Helmet (10) according to one of the preceding claims, characterized in that the blocks are oriented such that their height extends substantially in a vertical direction.
13. Helmet (10) according to one of the preceding claims, characterized in that the cap is produced by moulding.
14. Helmet (10) according to one of the preceding claims, characterized in that the blocks are hollowed out.

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