Improvements to Skull Protection Cell

Abstract

IMPROVEMENTS INTRODUCED IN A CRANIAL PROTECTION CELL, formed by an outer shell (11, 20) internally coated by absorbent material (12, 12), said material comprising a first layer (21) immediately below the shell, of closed cell foam, rigid or semi-rigid in contact with a second layer (22) of open cell viscoelastic foam, the interface between said first and second layers being provided with interdigitations comprising cavities (24) in said first layer in which protrusions (23), provided in said second layer, fit in a complementary and cooperative manner. Absorbent supporting material are further provided in the jaw region (32), maxillary regions (33, 34) and mastoid regions. When closed, the visor (37) is embedded in the corresponding opening of the cranial protection cell, and its opening occurs in two steps, the former comprising forward movement, and the latter upward rotation. The cranial protection cell (CPC) further comprises a removable chin guard (54) whose unlocking mechanism is driven by buttons (51) located on either side of the shell.

Claims

1-12, 14. (canceled)

15. A cranial protection cell, formed by an outer shell internally coated by a double layer of impact-absorbing material, the first outer layer, located adjacent to the shell, being provided with a plurality of recesses in which complementary protrusions, provided in the second innermost layerwhich is closer to the user's head-fit, wherein the material of said first layer has greater rigidity and lower density than the low resilient material of said second layer and that said protrusions are elastically deformable under mechanical stresses.

16. The cranial protection cell according to claim 15, wherein said first layer, provided with a plurality of cavities, is composed of closed cell polyurethane foam with a density between 40 and 85 kg/m.sup.3 and a mechanical compression strength between 120 kPa and 200 kPa.

17. The cranial protection cell according to claim 15, wherein said second layer consists of open cell viscoelastic foam with low resilience, with density between 50 and 95 kg/m.sup.3 and indenting force (40%) between 80N and 150N.

18. The cranial protection cell according to claim 15, further comprising impact absorbent material supporting pads in the chin area, corresponding to the front part of the jaw.

19. The cranial protection cell according to claim 15, further comprising impact absorbent material supporting pads in the face maxillary regions.

20. The cranial protection cell according to claim 15, further comprising the provision of impact absorbent material supporting pads in the mastoid regions.

21. The cranial protection cell according to claim 15, further comprising a visor with a flap embedded in the corresponding front opening of said shell, when closed.

22. The cranial protection cell according to claim 15, wherein said visor has each side affixed to the free end of a support rod, whose opposite end is integral with a pin-shaped axis associated with an external drive button located on the right and left sides of the shell.

23. The cranial protection cell according to claim 22, wherein a substantially horizontal through slit is provided on each side of the shell, at the rear and front ends, respectively, of a first and a second flair, which constitute non-permanent fitting means of said pin.

24. The cranial protection cell according to claim 23, wherein the aperture of the visor is performed in two steps, the first one comprising forward translational movement of said pin of said first flare towards said second flare of said through slit, the second step comprising the upward rotation of the support rod about said pin when fitted into said second flare.

25. The cranial protection cell according to claim 15, further comprising the provision of a removable chin guard and respective locking mechanisms located on either side of the shell.

26. The cranial protection cell according to claim 25, wherein each locking mechanism comprises an outer drive button coupled to the first end of a swing lock, whose second end is provided with a retainer claw fitted into the teeth of a retaining member attached to the chin guard

27. The cranial protection cell according to claim 15, wherein the shell material comprises a thermoplastic material obtained by reaction injection molding (RIM).

28. The cranial protection cell according to claim 21, wherein said visor has each side affixed to the free end of a support rod, whose opposite end is integral with a pin-shaped axis associated with an external drive button located on the right and left sides of the shell.

29. The cranial protection cell according to claim 28, wherein a substantially horizontal through slit is provided on each side of the shell, at the rear and front ends, respectively, of a first and a second flair, which constitute non-permanent fitting means of said pin.

30. The cranial protection cell according to claim 29, wherein the aperture of the visor is performed in two steps, the first one comprising forward translational movement of said pin of said first flare towards said second flare of said through slit, the second step comprising the upward rotation of the support rod about said pin when fitted into said second flare.

Description

DESCRIPTION OF THE DRAWINGS

[0058] The other characteristics and advantages of the invention will be evident from the description of a preferred, and non-limiting, embodiment, given as an example, and from the figures it refers to, wherein:

[0059] FIG. 1 illustrates, in a simplified way, the shear effect resulting from the application of rotational stress.

[0060] FIGS. 2-a and 2-b illustrate the increase of the torque applied to the user's head when increasing the thickness of the absorbent material layer.

[0061] FIG. 3 shows a state-of-the-art helmet fitted with a single layer absorbent material.

[0062] FIG. 4 illustrates another state-of-the-art helmet provided with two layers of expanded polystyrene foam (EPS) which differ only in that they have different densities.

[0063] FIG. 5 is a graph illustrating the relationship between angular acceleration and Diffuse Axonal Injury (DAI), developed by Gennarelli, T. A. in Head Injuries: How to Protect What, Snell Conference on HIC, May 6, 2005, Milwaukee, Wis., USA.

[0064] FIG. 6-a is a perspective view schematically showing the relationship between the layers of absorbent material used in the invention.

[0065] FIGS. 6-b and 6-c outline the deformation at the interface between the stiffer layer and the viscoelastic layer upon application of a tangential stress.

[0066] FIG. 7 shows, in detail, the provision of the absorptive material in the chin guard and in the maxillary region.

[0067] FIG. 8 shows, in detail, the provision of the absorptive material in the chin guard and in the mastoid regions.

[0068] FIGS. 9a-9e detail the mechanism of movement of the visor of the proposed cranial protection cell, illustrating its opening.

[0069] FIGS. 10-a, 10-b and 10-c detail the removable chin guard and its retention mechanism, according to the invention.

DETAILED DESCRIPTION

[0070] Referring now to FIG. 6-A, the absorbent means used in the invention comprise a first layer (21) of rigid or semi-rigid polyurethane foam of closed cells having a thickness of between 18 mm and 28 mm, a thickness of approximately 23 mm being preferably used. The density of this material varies between 40 and 85 kg/m.sup.3, preferably adopting an approximate value of 45 kg/m.sup.3 and its mechanical resistance to compression varies between 120 kPa and 200 kPa. The number of cells per cm.sup.3 and mechanical strength may vary. The invention is not restricted to the cited material, and equivalent materials with similar characteristics of density and mechanical behavior may be used.

[0071] In the impact, the head, compressing this layer, causes the collapse of the cells with consequent absorption of energy and increase of the time of impact, with permanent deformation, unlike the EPS, a fundamental function to prevent traumatic brain injury.

[0072] FIG. 6-A further shows the second layer 22, located between said first layer and the user's head. It is a viscoelastic foam with properties of high impact absorption (up to 90%), sound and vibrations, and due to the soft touch, reducing points of tension in the skin. Its function is to provide comfort and, at the moment of impact, to distribute the pressure that the head will make on the rigid layer and to be the first, and perhaps the most important, impact energy absorption system. It has a role similar to that of the cerebrospinal fluid in the central nervous system.

[0073] This second layer consists of an open cell foam, with a density between 50 and 95 kg/m.sup.3, preferably adopting the value of 65 kg/m.sup.3. The indentation strength at 40% of this material is between 80N and 150N. The thickness of this layer varies between 12 mm and 22 mm, with a preferential value of approximately 17 mm. Like the previous one, its configuration can vary taking into consideration several parameters, being able to be replaced, as before, by another material, provided that it has similar mechanical performance.

[0074] As shown by FIG. 6-A, said layers are embedded in interdigitations so that the assembly has a final thickness of not more than 35 mm, preferably 30 mm, and not 40 mm as would be expected from the sum of its thicknesses. New materials, provided that with the same mechanical behavior defined herein, may even result in the future decrease of this thickness.

[0075] Still according to FIG. 6-a, the surfaces at the interface between said layers have indented fittings, i.e. embossed configurations. In this figure, as well as in the sectional view of FIG. 6-B, a plurality of cavities 24 are noted in the first layer 21, a plurality of protrusions 23 corresponding thereto in the second layer 22, said protrusions being positioned coincidently with said cavities, in which they fit cooperatively and complementarily. The figure further shows a comfort fabric 26 between the second layer 22 and the user's head 25.

[0076] The indented fitting of the foams allows an increase in the impact absorbing surface, an increase in the deformation time and, more importantly, allows a partial longitudinal displacement between them to minimize torque on the brain. Such displacement is shown in cross-sectional views 6-b and 6-c.

[0077] As shown in FIG. 6-C, part of the tangential forces acting on the helmet are dissipated by the deformation of the indentations 23, thus there is only partial transmission of the forces to the motorcyclist's head (which is symbolized by the length of the arrows). Also, in a radial impact the head begins to compress the viscoelastic and then the semi-rigid, the first deformation of which is done sidewards (into the cavities) and only then for the longitudinal direction. This increases the impact time by decreasing the force, as demonstrated previously.

[0078] FIG. 7 is an illustrative view of support of the absorbent material 32 in the chin guard 31, which surrounds the submental region creating an additional attachment point. In addition to this material, the supports 33 and 34 of the absorptive material are provided in the maxillary regions, allowing greater protection of the user in case of frontal impact.

[0079] FIG. 7 further shows one of the external drive buttons 35 of the visor lock, as will be described in connection with FIG. 9.

[0080] As shown in FIG. 8, the invention further provides support points 36 of the absorptive material in the mastoid regions, thereby creating a third retention point, in addition to the submental region and jugular strap.

[0081] The set of FIGS. 9-a . . . 9-e refers to the visor of the cranial protection cell (PC) of the invention. FIG. 9-A is a cross-sectional internal view of the cranial protection cell showing the elements forming part of the visor movement mechanism, as will be described below.

[0082] FIG. 9-B is a partial external view of the CPC showing one of the drive buttons 35 of the mechanism, located on the side of the shell, there being a similar, symmetrically disposed button on the opposite side of the shell.

[0083] According to the detailed internal view of FIG. 9-C, this button is internally associated with a pin 40 which is the axis of rotation of the mechanism suspending the visor 37 which is attached to one end of a rod 38 whose other end is integral with said pin. According to the invention, there is provided a substantially horizontal through slit 39 on each side of the shell, which is provided at both ends of the flares on which said pin engages; in the normally closed position, the pin 40 fits in the first flare 39a. As can be seen, in this position the lower edge of the visor is recessed relative to the front face 41 of the shell, which prevents its accidental opening by the wind pressure when at high speeds.

[0084] To open the visor, buttons 35, which disengage each of the pins 40 from the first flare are pushed horizontally forward the set consisting of the pins 40, rods 38 and visor 37 to the position shown in FIG. 9-d, where pins 40 fit into the second front flare 39b of each of said through slits. As shown in the figure, the visor is now in an advanced position relative to the front of the shell.

[0085] To complete the aperture, the rods rotate about the fulcrum pins 40, as indicated in FIG. 9-E, this rotation being limited by the contact of safety locks 38a at the ends of the rods 38 with the upper edge 42 of the shell opening.

[0086] FIGS. 10-a, 10-b and 10-c refer to a CPC chin guard. FIG. 10-a illustrates a side view of the CPC with the chin guard in its normal position. This figure illustrates one of the buttons 51 which drive the chin guard unlocking mechanism, wherein another identical button is provided on the opposite side of the shell.

[0087] FIG. 10-b is a detailed view corresponding to the B-B section of the previous view. The detail shows the button 51, the swing lock 52 provided with a retainer claw (not referenced), the toothed retaining element 53 which is attached to the groove 54 and the main shell 11 of the CPC.

[0088] As shown in FIG. 10-b, the button 51 is coupled to the first end of the swing lock 52 by means of a shaft (not referenced). Hence, when the button 51 is pressed the lock will oscillate through a seesaw effect, unlocking the retainer claw at the second end of the teeth of the retaining member 53, the withdrawal of the chin guard 54 being then released by simple forward sliding, as shown in FIG. 10-c.

[0089] In brief, the cranial protection cell (CPC) of the present invention stands out from the conventional helmets for a number of advantages, among which the following stand out: [0090] face protective structure, protecting against frontal impacts; [0091] reduction of the risk of Torque and Diffuse Axonal Injury [0092] reduced weight, around 1 kg, with more comfort and less aerodynamic drag; [0093] visor fitting system, increased optical efficiency and removable chin guard; [0094] absorptive material in the mastoid regions; [0095] better CPC retention in the user's head; [0096] smooth shell without protrusions, avoiding the head locking against some external obstacle, which contributes to reduce or prevent torque.

[0097] Thus, the Cranial Protection Cell represents a radically innovative concept when compared to known helmets, overcoming the technique known from the functional point of view, extending in a significant and scientific way the protection of the skull and, consequently, of the brain, which is, in synthesis, that what we are.