BACKGROUND OF THE INVENTION

The present invention relates to a protective head covering, consisting mainly of a partial sphere-shaped shell, fitted with an inner lining, to protect the wearer from head injury in case of impact during accidents Such helmets are worn by race car drivers, ski racers, motorcycle riders and the like and consist of a shell, usually constructed from layers of resin and fibre and fitted with a foam inner lining, which is shaped to conform tightly to the head of the wearer. Such helmets may be constructed with or without an integral chin strap part and may be equipped with or without a transparent visor to cover the sight opening.

The impact absorbing qualities of the shell and lining of such a helmet must meet very stringent requirements and any improvement in this area is therefore most desirous, especially when at the same time raising the comfort level for the wearer.

Helmets using a resin and fibre constructed shell are already well known. However, such conventional shell construction relies only on surface curvature, as dictated by the shape of the head, and the shell\'s resin and fibre combination to provide the resilience and necessary strength to withstand impact.

The construction method for such a shell usually employs a mould into which layers of resin and fibre are formed into the required shape. Hence, the shape of the mould is entirely responsible for the forming and layering of resin and fibre into the shape of the finished shell.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a helmet shell, which, by way of its moulding method, has increased resilience, strength and impact resistance, without affecting the overall even thickness and weight of the shell wall.

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It is another object of the present invention to provide a helmet shell, which, by way of its moulding method obtains an overall shell surface with reduced drag resistance at all speeds, without affecting size and dimensions of the helmet in general.

According to the invention there is provided a protective helmet for race car drivers, ski racers, motorcycle riders and the like, comprising a shell of substantially spherical shape, constructed by way of a moulding process, using bonded layers of resin and fibre, to provide the necessary resilience and resistance to impact, at a lowest possible weight to strength ratio, wherein the bonded layers of resin and fibre, instead of following directly the usual curvature of the shell contour, create a series of small rises and depressions, alternately and adjacent to each other across the surface of the shell in a determined pattern, and wherein a depression on the exterior of the shell surface results in a rise on the interior of the shell and vice versa, and whereas all rises or depressions are preferably circular in shape and are arranged such, that, when they are viewed in cross section in any direction, appear as a continuous wave pattern or type of corrugation, with such corrugation or embossing of course to be generally known to increase rigidity and resilience.

Furthermore, such moulded shell surface, in addition to its increased strength, creates, when in movement, certain improved air flow velocities across its surface curvature and thereby aiding in the reduction of drag normally existing at the rear of a moving helmet. This reduction of drag results in less lift and buffeting, which is especially problematic for race car drivers, and eliminates a large amount of pressure on the neck muscles of the wearer and generally increases the overall comfort level. Ski racers might experience enough reduction in drag to gain a winning edge.

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INTRODUCTION, TO THE. DRAWINGS

Figure 1 of the drawings appended hereto depicts a preferred embodiment of the present invention, comprising a section through a resin and fibre layered shell wall, as located in Figure 2 at \'A-A\', illustrating the corrugation arrangement with its corresponding mould pattern;

Figure 2 of the drawings depicts a plan view of a portion of the layered helmet shell, showing the pattern of rises or depressions as appearing on the exterior side of the shell;

Figure 3 of the drawings depicts a plan view of a portion of the layered helmet shell, showing the pattern of rises or depressions as appearing on the interior side of the shell, corresponding to Figure 2;

Figure 4 of the drawings depicts a view of the shell wall with its rises or depressions in a combination of \'section through* and \'elevation beyond\' illustration;

Figure 5 of the drawings depicts a view of the shell wall in section through location \'B-B* as indicated in Figures 2 and 3.

Figure 6 of the drawings depicts a section through the shell wall showing some alternative shapes of depressions.

DETAILED DESCRIPTION OF THE DRAWINGS For the purpose of understanding the principle of the present invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contem¬ plated as would normally occur to one skilled in the art to which the invention relates.

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Figure 1 of the drawings shows an elevated view through a section of the helmet shell wall as located in figures 2 and 3 at section line \'A-A\', comprising resin layers b and c imbedding fibre layer d within, evenly following the corrugation contour line of the shell wall as formed in mould a shown in view through a section. This section view illustrates the arrangements of rises and depression creating the shell wall\'s corrugation effect, with depression h resulting in rise f and rise g resulting in depression e on their opposite sides. Increased shell wall strength can be obtained when fibre layer d is imbedded always in the centre of resin layers b and c, following all contour lines. In a resin and chopped fibre application or injection type moulding process, increased shell strength can be obtained by maintaining even shell wall thickness following all corrugation contour lines.

Figure 2 of the drawings depicts a plan view of a portion of a helmet shell, representing the exterior surface side of such a shell, showing depressions j and h and rises g and k in an evenly patterned arrangement, which, when viewed through section line \'A-A\' present an identical pattern as viewed through section line \'B-B\', and, when viewed through section line \'C-C present an identical pattern as when viewed through section line \'D-D\'. Such even pattern exists all across the helmet shell.

Figure 3 of the drawings depicts a plan view of the same portion of helmet shell as viewed in figure 2, but representing the interior surface side of that portion of the shell. The pattern appears identical except for depressions h and j, as appearing in figure 2, to be now rises f and 1, and rises g and k, as in figure 2, now to be depressions e and m. Depressions e and rise f correspond to e and f as appearing in figure 1.

Figure 4 of the drawings depicts a combination of a view through section line \'A-A\', as shown in figure 1, and an elevated view beyond such section line view.

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This illustrates the corrugation effect using the even shell wall thickness p to increase the overall shell wall dimension to q, increasing shell strength without considerably increasing weight or material of such shell construction. Dimension q is the distance between points g, gl and g2 etc. and points f, fl, f2.

Figure 5 of the drawings depicts an elevated view through section line \'B-B\' as indicated in figures 2 and 3, and illustrates the identical corrugation pattern effect when compared with view through section line \'A- A\' , where points k and j and points m and 1 correspond with points g and h and points e and f, as in figure 1, respectively.

Figure 6 of the drawings depicts a section through the shell wall illustrating a different corrugation pattern, where depressions k and j and rises m and 1 show alternate shapes to the shapes shown in figure 5.

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