EP1016352A1

EP1016352A1 - Helmet with multiple density inner cap

Info

Publication number: EP1016352A1
Application number: EP98830815A
Authority: EP
Inventors: Maurizio Casale
Original assignee: Camau System Di Casale and C SNC
Current assignee: Camau System Di Casale and C SNC
Priority date: 1998-12-31
Filing date: 1998-12-31
Publication date: 2000-07-05

Abstract

The invention refers to an helmet of the type comprising an outer shell (30) substantially rigid and an inner cap, made of a material suitable for absorbing eventual shocks, comprising at least two superimposed layers having different densities, a low density inner layer (2), in contact with the user's head, and an outer layer (10) having an higher density, interposed between the inner layer (2) and the outer shell (30).

Description

The present invention refers to a protective helmet.
More particularly the invention refers to an helmet of the type comprising a substantially rigid outer shell and an inner cap made of a material suitable for absorbing eventual shocks.
As it is well known, the helmets, whether for sports or for working spaces, are generally realised coupling to an outer shell made of plastic material, an internal padding made of a shock-absorbing material, subsequently covered by a tissue or other material for a better comfort.
The outer shell can be molded using a coloured plastic material and afterwards decorated at will by means of paint and/or plastic adhesive sheets having various shapes and colours, according to uses.
Very important factors, whether for sports or for other fields, as for example in accident prevention, are the lightness and the aeration of the protective helmets.
It is indeed well known the use of helmets provided with aerating through holes which allow at the same time a better aeration and a lightening of the helmet itself, making less wearisome its presence on user's head.
This type of helmets provided with aerating holes is used particularly by those who practice cycling, skate-boarding, roller-skating, etc.
For other uses, as for example in the accident prevention, ski or ice skating, it is instead preferable that the outer shell is completely closed, in order to guarantee an higher robustness and rigidity and, consequently, better protection.
The inner cap, molded in a single element, is normally realised in foamed plastic material, for example polystyrene foam. That material has in fact suitable characteristics of lightness, shock resistance, shock absorbing capacity, and low cost.
Nevertheless, in order to guarantee a sufficient compactness and rigidity to the cap, it is necessary to mold the polystyrene foam at a relatively high density, with a corresponding high specific weight, negatively affecting the lightness of the helmet.
Moreover the high rigidity of the inner cap can reduce the internal comfort of the helmet.
A first object of the present invention it is therefore to provide a helmet having a particularly light and comfortable inner cap but having high safety characteristics.
Another object of the present invention it is to provide a particularly light helmet easy and cost effective to manufacture.
The above objects of the present invention are reached from an helmet as claimed in the accompanying claims.
According to the invention the helmet's inner cap comprises two superimposed layers having different densities, a low density inner layer in contact with user's head, and an outer layer having higher density.
Thanks to the presence of the low density inner layer, less rigid and lighter, the helmet according to the invention has better comfort characteristics in respect to prior art but allows, thanks to the high density outer shell, to maintain high safety characteristics.
The above objects will result more clear from the detailed description of a preferred embodiment of the helmet according to the invention with particular reference to the accompanying drawings in which:
figure 1 is a lateral view of a first layer of an inner cap of an helmet, according to a first embodiment of the present invention;
figure 2 is a lateral view of a second layer of an inner cap of an helmet, according to a first embodiment of the present invention;
figure 3 is a top view of a first layer of an inner cap of an helmet, according to a second embodiment of the present invention;
figure 4 is a top view of a second layer of an inner cap of an helmet, according to a second embodiment of the present invention; and
figure 5 is a schematic sectional view of a portion of an helmet according to the present invention.
With reference to Figures 1 and 2 it is shown a first preferred embodiment of an inner cap of an helmet according to the invention.
The inner cap comprises two separated elements, or layers, shown respectively in Figure 1 and in Figure 2, made of foamed plastic material, having different densities and easily matchable by gluing.
Figure 1 shows laterally the inner layer 2 of the cap, comprising a portion 2 substantially hemispherical, which defines an inner volume suitable for containing the user's head, and a perimetrical edge 4.
The perimetrical edge 4, which is larger than the hemispherical portion 6, provides a perimetrical supporting surface 8 for the outer layer 10 of the cap, shown in Figure 2.
The inner layer 2, in contact with the user's head, is made of low density polystyrene foam, for example 70 g/l, a light material, relatively soft and suitable for easily absorbing an eventual shock.
The outer layer 10, shown in Figure 2, is made of a single piece of high density polystyrene foam, for example a density double compared with the density of the inner layer, in order to confer rigidity and robustness to the helmet.
The outer layer 10 defines internally an hollow volume, having a shape complementary to the external surface of the portion 6 of the inner layer 2, so that it can be perfectly superimposed and it presents a very large gluing surface.
In this way, by gluing the outer layer 10, rigid and strong, on the inner layer 2, light and easily compressible in case of impact, it is obtained a cap which is light, particularly comfortable, very robust and safe in case of impact.
Alternatively the inner layer can be made of three or more superimposed layers, having different densities, glued together in order to obtain a single element.
In this first embodiment the cap is not provided with aerating through holes and both layers, made of a single piece, can be manufactured using a mold for plastic material simple and cheap.
Moreover, in order to realise helmets of different sizes, it is sufficient to mold inner layers having different thickness, using only one mold for the outer layer and for the protective/decorative outer shell.
In order to complete and finish externally the helmet it is glued, on the outer layer 10, a decorative outer shell, preferably made of transparent or coloured polycarbonate.
The decorative shell can be painted at will, according to models, uses and fashion, and can be provided with decorative adhesive sheets.
The function of the outer shell is mainly decorative, however, as it is strongly glued to the cap, it reinforces the structure and the rigidity of the helmet.
Alternatively the outer shell could be co-molded together with the outer layer 10 of the cap, using well known co-molding techniques for plastic materials, obtaining a more compact and robust structure and avoiding a gluing phase.
In Figures 3 and 4 it is schematically shown a second embodiment of a cap for an helmet according to the present invention.
The cap consists of two separate elements, or layers 14 and 24, shown in top views, respectively in Figure 3 and in Figure 4. The layers 14 and 24 are made of foamed plastic material, have different densities and are provided with aerating through holes.
An inner layer 14, having a hemispherical shape, made of low density polystyrene foam, for example 70 g/l, is provided with a plurality of through holes 16 and with a plurality of lowered channels 18 which connects the through holes 16 between them and with back openings 20 suitable for the outlet of the air from the helmet.
The inner layer 14 comprises perimetrically a supporting edge 22 for the outer layer 24 of the cap, provided with some dowels or pins 26 suitable for coupling with corresponding holes or grooves made in the lower edge of the outer layer 24.
The outer layer 24, shown in Figure 4 overlapped to the inner layer 14, comprises three separate portions 24a, 24b and 24c, glued together to form a single cap. Each portion is made of high density polystyrene foam, for example having a density double than the density of the inner layer 14, in order to guarantee rigidity and robustness to the helmet.
Alternatively the three external portions 24a, 24b and 24c can be made of materials having different densities, for example could be necessary, in order to make more robust a particular area of the helmet, to realise one portion with a density particularly high, leaving unaltered the remaining portions.
The three portions 24a, 24b and 24c of the external layer form internally a hollow volume having a shape complementary to the external surface of the inner layer 2, in order to allow a perfect superimposition.
The rigid and robust outer layer 24 is thus glued onto the inner layer 14, which is light and easily compressible in case of impact, obtaining a light cap, very robust, particularly comfortable and safe in case of impacts.
As it is shown in figure 4, each portion of the outer layer 24a, 24b, 24c, is provided with a plurality of through openings 16 in correspondence with the through openings in the inner layer 14.
The subdivision of the outer layer 24 in separate portions makes easier its quantity production in that, during manufacturing, each portion can be easily taken out from the mold along a single direction, a direction coinciding with the axis of the through openings 16.
In this embodiment it is as well possible to realise the inner layer in different thickness, in order to obtain different size helmets in a simple and cheap way, or to realise the cap in three or more superimposed layers.
Onto the outer layer 24 it is then glued, to complete and finish the helmet, a coloured shell made of polycarbonate, painted or decorated with adhesive sheets.
The decorative shell, firmly glued onto the cap, improves also the structural robustness of the helmet and its rigidity.
Alternatively the decorative shell, subdivided in suitable portions, can be co-molded with the single portions of the outer layer 24, using well known comolding technics for plastic materials.
The three portions, each provided with a part of the shell, are then glued together and glued to the inner layer 14.
In figure 5 it is shown, in a sectional view, a particular of an helmet according to the present invention, for example an helmet incorporating the double layers cap shown in Figures 1 and 2, in which are visible the inner layer 2 made of low density foam polystyrene, the outer layer 10 made of high density foam polystyrene and the decorative shell 30.
The two superimposed layers having different densities which form the inner cap of the helmet according to the invention confer better comfort characteristics and allow, thanks to the high density outer layer, to reach high safety levels.
Moreover, thanks to the presence of the low density inner layer, the helmet according to the invention is lighter than an helmet provided with a single density cap and has equivalent technical and esthetical characteristics.

Claims

Helmet suitable for containing a user's head comprising an outer shell (30) substantially rigid and an inner cap made of a material suitable for absorbing eventual shocks, characterised in that said inner cap comprises at least two superimposed layers (2,10;14,24) having different densities.
Helmet according to claim 1, characterised in that said cap comprises at least an inner layer (2,14), in contact with the user's head, and an outer layer (10,24), having a density higher than the density of the inner layer, interposed between the inner layer and the outer shell (30).
Helmet according to claim 2, characterised in that the layers (2,14;10,24) which form the cap are made of foamed plastic material.
Helmet according to claim 3, characterised in that the inner layer (2,14) and the outer layer (10,24) of the cap are glued together.
Helmet according to claim 3, characterised in that the inner layer (2,14) of said cap is made of polystyrene foam having a certain density while the outer layer (10,24) is made of polystyrene foam having a density double then the density of the inner layer.
Helmet according to claim 3, characterised in that the outer layer (10,24) is co-molded with the outer shell (30).
Helmet according to claim 1, characterised in that an outer layer (24) of said cap consists of the union of two or more portions (24a,24b,24c).
Helmet according to claim 7, characterised in that the two or more portions of the outer layer (24) are made of materials having different densities.
Helmet according to claim 7, characterised in that each portion of the outer layer (24) is co-molded with a corresponding portion of outer shell and is glued together with adjacent portions of outer layer and with said inner layer (14).
Helmet according to claim 9, characterised in that each of said two or more portions is provided with means for its centering (26) with other portions and with the inner layer.
Helmet according to any of the preceding claims, characterised in that the inner cap and the outer shell comprise one or more aerating through holes (16) which connect the inside space of the helmet, suitable for containing the user's head, with the outer space.